text:
# Superconductivity (cond-mat.supr-con)

• We analyze the finite temperature phase diagram of the boson-fermion-Hubbard model with Feshbach converting interaction, using the coherent state path integral method. We show, that depending on the position of bosonic band, this type of interaction, even if weak, it can drive the system into the resonant superfluid phase in the strong bosonic interaction limit. It turns out that this phase can exist for an arbitrary number of fermions (i.e. fermionic concentration between 0 and 2) but with the bosonic particle number pinned to an integer value. We point out that the standard time of flight method in optical lattice experiments can be adequate technique to confirm the existence of this resonant phase. Moreover, in the non-resonant regime, the enhancement of critical temperature of superfluid phase due to Feshbach interaction is also observed. We account this interesting phenomena for hole or particle-like pairing mechanism depending on the system density and mutual location of fermionic and bosonic bands.
• We use neutron polarization analysis to study temperature dependence of the spin excitation anisotropy in BaFe$_2$As$_2$, which has a tetragonal-to-orthorhombic structural distortion at $T_s$ and antiferromagnetic (AF) phase transition at $T_N$ with ordered moments along the orthorhombic $a$-axis below $T_s\approx T_N\approx 136$ K. In the paramagnetic tetragonal state at 160 K, spin excitations are isotropic in spin space with $M_a=M_b=M_c$, where $M_a$, $M_b$, and $M_c$ are spin excitations polarized along the $a$, $b$, and $c$-axis directions of the orthorhombic lattice, respectively. On cooling towards $T_N$, significant spin excitation anisotropy with $M_a>M_b\approx M_c$ develops below 3 meV with a diverging $M_a$ at $T_N$. The in-plane spin excitation anisotropy in the tetragonal phase of BaFe$_2$As$_2$ is similar to those seen in the tetragonal phase of its electron and hole-doped superconductors, suggesting that spin excitation anisotropy is a direct probe of doping dependence of spin-orbit coupling and its connection to superconductivity in iron pnictides.
• We review the recent progress in understanding the transport properties of spin-split superconductors under non-equilibrium conditions. Recent experiments and theories demonstrate a rich variety of transport phenomena occurring in devices based on such materials that suggest direct applications in thermoelectricity, low-dissipative spintronics, radiation detection and sensing. We discuss different experimental situations and present a complete theoretical framework based on the quantum kinetic equations. Within this framework we provide an accurate description of the non-equilibrium distribution of charge, spin and energy, which are the relevant non-equilibrium modes, in different hybrid structures. We also review experiments on spin-split superconductors and show how transport measurements reveal the properties of the non-equilibrium modes and their mutual coupling. We discuss in detail phenomena like spin injection and diffusion, relaxation of the different electronic degrees of freedom, very large thermoelectric effects and the non-equilibrium dynamics of spin-split superconductors.
• Unequivocal signatures of Majorana zero energy modes in condensed matter systems and manipulation of the associated electron parity states are highly sought after for fundamental reasons as well as for the prospect of topological quantum computing. In this Letter, we demonstrate that a ring of Josephson coupled topological superconducting islands threaded by magnetic flux and attached to a quantum dot acts as an excellent parity-controlled probe of Majorana mode physics. As a function of flux threading through the ring, standard Josephson coupling yields a $\Phi_0=h/(2 e)$ periodic features corresponding to $2\pi$ phase difference periodicity. In contrast, Majorana mode assisted tunneling provides additional features with $2\Phi_0$ ($4\pi$ phase difference) periodicity, associated with single electron processes. We find that increasing the number of islands in the ring enhances the visibility of the desired $4\pi$ periodic components in the groundstate energy. Moreover as a unique characterization tool, tuning the occupation energy of the quantum dot allows controlled groundstate parity changes in the ring, enabling a toggling between $\Phi_0$ and $2\Phi_0$ periodicity.
• A subtle balance between competing interactions in strongly correlated systems can be easily tipped by additional interfacial interactions in a heterostructure. This often induces exotic phases with unprecedented properties, as recently exemplified by high-Tc superconductivity in FeSe monolayer on the nonmagnetic SrTiO3. When the proximity-coupled layer is magnetically active, even richer phase diagrams are expected in iron-based superconductors (FeSCs), which however has not been explored due to the lack of a proper material system. One promising candidate is Sr2VO3FeAs, a naturally-assembled heterostructure of a FeSC and a Mott-insulating vanadium oxide. Here, using high-quality single crystals and high-accuracy 75As and 51V nuclear magnetic resonance (NMR) measurements, we show that a novel electronic phase is emerging in the FeAs layer below T0 ~ 155 K without either static magnetism or a crystal symmetry change, which has never been observed in other FeSCs. We find that frustration of the otherwise dominant Fe stripe and V Neel fluctuations via interfacial coupling induces a charge/orbital order with C4-symmetry in the FeAs layers, while suppressing the Neel antiferromagnetism in the SrVO3 layers. These findings demonstrate that the magnetic proximity coupling is effective to stabilize a hidden order in FeSCs and, more generally, in strongly correlated heterostructures.
• Electronic structure has been studied in lightly electron doped correlated spin-orbit insulator Sr$_2$IrO$_4$ by angle-resolved photoelectron spectroscopy. We have observed coexistence of the lower Hubbard band and the in-gap band, the momentum dependence of the latter traces that of the band calculations without on-site Coulomb repulsion. The in-gap state remained anisotropically gapped in all observed momentum area, forming a remnant Fermi surface state, evolving towards the Fermi energy by carrier doping. These experimental results show a striking similarity with those observed in deeply underdoped cuprates, suggesting the common nature of the nodal liquid states observed in both compounds.
• We report ab-plane Hall Effect and magnetoresistivity measurements on La2-xCexCuO4 thin films as a function of doping for magnetic fields up to 14T and temperatures down to 1.8K. A dramatic change in the low temperature (1.8 K) normal state Hall coefficient is found near a doping Ce=0.14. This, along with a nonlinear Hall resistance as a function of magnetic field, suggests that the Fermi surface reconstructs at a critical doping of Ce= 0.14. A competing antiferromagnetic phase is the likely cause of this Fermi surface reconstruction. Low temperature linear-in-T resistivity is found at Ce=0.14, but anomalously, also at higher doping. We compare our data with similar behavior found in hole-doped cuprates at a doping where the pseudogap ends
• We study the emergent band topology of two-dimensional sheets of sub-gap Andreev bound states in the three-terminal Josephson junctions. We scrutinize on the symmetry constraints of the scattering matrix in the normal region connecting superconducting leads that enable for the topological nodal points in the spectrum of Andreev states. When the scattering matrix possesses time-reversal symmetry the gap closing points are accidental and topologically trivial as they carry vanishing Berry fluxes. In contrast, for the time-reversal-broken case, we find topological monopoles of the Berry curvature and corresponding phase transition between states with different Chern numbers. The latter is controlled by the structure of the scattering matrix that can be tuned by a magnetic flux piercing through the junction area in a three-terminal geometry. Topological regime of the system can be identified by nonlocal conductance measurements that we compute explicitly for a particular parametrization of the scattering matrix in the case where each reservoir is connected by a single channel.


text:
Dear teacher , Please help me with the below question ?? A field is 102m long and 25 m broad. A tank 10 m long, 5 m broad and 4 m deep is dug out from the middle of the field and the earth removed is evenly spread over the remaining part of the field. Find the rise in the level of the remaining part of the field in cm .

• 2
What are you looking for?

format: plain


text:
Get terrain elevation for a given polygon

pointDTM_get(polygon, distance = 1, print_iter = TRUE)

## Arguments

polygon

the polygon layer with only one object (its area is limited to the 20 ha * distance parameter), the input coordinate system must be EPSG:2180

distance

distance between points in meters (must be integer and greater than 1)

print_iter

print the current iteration of all (logical, TRUE default)

## Value

a data frame with vector points and terrain elevation (EPSG:2180, Vertical Reference System:PL-KRON86-NH)

## Examples

if (FALSE) {
library(sf)
polygon_path = system.file("datasets/search_area.gpkg", package = "rgugik")
}


text:
# Windows Vista Delayed Again (1 Viewer)

### Users Who Are Viewing This Thread (Users: 0, Guests: 1)

#### dduardo

##### Technology Mentor
Staff Emeritus
Here is the official press release:

Businesses will be able to get Vista this November while everyone else will have to wait until January 2007.

It was supposed to be released in the fall of 2006, just in time for the holidays, but it isn't going to work out that way.

On a related note, the next version of OS X is still on target to be released this year.

Last edited by a moderator:

#### scott1

dduardo said:
Businesses will be able to get Vista this November while everyone else will have to wait until January 2007.
Why do businesses get it frist?Do they have to pay more because of commical lincening and they get it eariler because MS wants to make more money of the commical lincen then everone elese and they want to make sure there's more copies for them.

#### dduardo

##### Technology Mentor
Staff Emeritus
It's strange that businesses are getting it first because the reason Microsoft says they are delaying Vista is over security concerns.

#### Nothing000

They are going to go out of business because of this one. The competition is going to eat them alive.

#### Nothing000

Dude, I am telling you. They are going under within the next 3 to 6 months.

#### Nothing000

What the heck happened with that anti-trust case? I thought they were forced to start another company to compete with, or allow another company to take over so much of the market to create competition, or something along those lines.
Wasn't the rulling something like that or were they just ordered to pay fines?

#### Anttech

Exactly why do you think that?

#### Nothing000

Think what, that they will go under?

#### Anttech

yes... back up your statements with some facts...

#### Nothing000

They will go out of business because of all of the stiff competition. I was just kidding. Get it? They barely have competition. Haha. Funny, funny.

#### franznietzsche

dduardo said:
It's strange that businesses are getting it first because the reason Microsoft says they are delaying Vista is over security concerns.

Actually, I think its hilarious. Either they're lying about why they're delaying, the business version has a different codebase, or more likely, they don't actually care about the security of their customers.

Staff Emeritus
Gold Member

#### dduardo

##### Technology Mentor
Staff Emeritus
Moonbear, you spoke too soon. Office is now official delayed until 2007:

http://www.eweek.com/article2/0,1895,1942069,00.asp

---------------------

There is also a lot of buzz on the internet today about another possible Vista development reset. Microsoft is even bringing in people from the Xbox team to help out:

http://www.smarthouse.com.au/Computing/Platforms?Article=/Computing/Platforms/R7G5G6U4 [Broken]

The last reset was a few years ago when they switched from the windows xp code base to the windows 2003 code base.

------------------

The programmers working for Microsoft aren't that happy either:

"Basically we do not believe Vista will make January 2007 or even March 2007. Anyone with any access knows what a frankenstein's monster NT is on the inside. At some point there is a law of diminishing returns trying to do anything to it at all, it seems like that limit is being reached today. The release is pushed back because of bugs but fixing those bugs will create more bugs. It is just godawful to be honest. And the process gets in the way at every step.

At some point we will have to do something and i know at least some in my team privately agree with me. We will have to throw out everything and start again. This is what Apple did with OSX, and sure it was painful, but it worked and now they're kicking our asses. We should have done that in 2000. Now it is even more obvious we should do it. Start again and just run a compatibility layer on top. Apple did it with classic why can't we???

IF we manage to ship vista at ALL then it is a miracle and the absolute last rev we can possible do working like this. It is insane the manhours wasted rearranging a house of cards. We need to START AGAIN PEOPLE.

I honestly do not believe we can ship another OS in this way. Either we do an OSX or Vista is the end of the line, YOU KNOW IT'S TRUE!!!

And BTW mini PLEASE enable https on your comments page. You would have to be nuts to post here from inside the network via plain http. Anyone else wants to do it, do what i do, email the comment (encrypted) to a friend and get him to post it. Anyone who thinks SMG doesn't have a filter looking at anything to or from minimsft is kidding themselves."

==========

"Being a 10 year vet I feel ashamed and sad. This company is a mess on so many levels."

==========

"Vista is a disaster. The "reset" you mention is nothing less than a FAILURE to SHIP. What you're working on now isn't Longhorn, it's SP4. Don't kid yourself.
If you want to salvage your career, flee to Office, or better yet, get the heck out of the company before it all collapses."

%%%%%%%%%%%%%%

It is looking more and more like another Windows ME disaster, or even possibly worse.

Last edited by a moderator:

#### Ivan Seeking

Staff Emeritus
Gold Member
I just bought a new computer with XP SP2 installed.

When I bought my old computer I jumped to ME as it was just out. Won't do that again. Also, a few months later when I installed XP in place of ME, my software warranty was void. Anyway, at this point I allow about a year before for going with major upgrades.

#### -Job-

I got a Windows Vista copy from MSDN but the serial didn't work, so i couldn't preview it. I will try again when i have the time.

#### franznietzsche

None of that is surprising. Vista was originally supposed to ship in '04 ? (I believe, maybe it was '05). They've already dropped every real new feature as of late last year, leaving only MASSIVE new MINIMUM requirements and a shiny new interface to waste those required resources on. Oh and "security" too. They finally took care of that. Right?

I certainly wouldn't say that the company is in any immediate financial danger, but if they don't pull a hail mary on this, they are gonna be badly injured strategically. Especially if this ends like ME (or worse). They're gonna lose a lot of credibility with how much they've staked on Vista, and how long it would take them to start from scratch. Think of the boat they're in. They can't do what Apple did and grab a UNIX base for a new OS, they'd lose all credibility among what brand loyalists they have. Well maybe not, given how sheepish such people are. The next few years are going to be very interesting for them, strategically. Gates is a brilliant businessman, I think it will be interesting to see what he does to handle it. If he's grown weak and ineffectual through his own success, accustomed to not having to compete, or if he'll be able to pull together, show strong leadership and maintain dominance. It'll be very interesting indeed.

#### -Job-

The Windows NT Kernel is not as bad as people might have you believe, but i'm not an expert in this matter, i only took one Operating Systems course. Maybe some expert will come around here and enlighten me.

#### Anttech

NT is ok, it is a true multiuser enviroment, although not many people treat it that way...

This thread is funny, they have delayed a release due to some incompitant project managment, and we have people saying that M$will go bankrupt, we have links to sites predicting that M$ will "throw away" uncountable manhours of work because of a perception that the code base is bad....

I'll reserve judgement untill I see some actual facts rather than hearsay!

It probabaly wouldnt be a bad thing for me or any other IT proffesional if M\$ lost a lot of market share, at least the market would open up, and more technology would come out and thus more work ;) BUT i doubt that is going to happen... Anyway the merger of Alcitel and Lucent is more interesting to me (off topic I know, sorry)

### The Physics Forums Way

We Value Quality
• Topics based on mainstream science
• Proper English grammar and spelling
We Value Civility
• Positive and compassionate attitudes
• Patience while debating
We Value Productivity
• Disciplined to remain on-topic
• Recognition of own weaknesses
• Solo and co-op problem solving


text:
# Material balance without chemical reactions

This is a practice question that I am trying. I am a student learning about material balance-

I am trying to find the mass composition of stream D. The one written in pencil is the values that I have found in advanced-

My attempt-

I have made a material balance around separator 2 ignoring the recycle stream,

I done up a component X balance-

$1250 X + (120 \times 0.3) = (379.08 \times 0.374) + (90.92 \times 0.222)$

I solve for x $= 0.10076$

Similarly,I done up a component Y balance-

$125 Y + (120 \times 0.7) = (379.08\times0.626) + (90.92\times 0.778)$

I solve for Y $= 0.1792$

I know this is wrong as the composition of X and Y total does not add up to 1. Where did I go wrong or what must I do ?


text:
Enable contrast version

# Tutor profile: Raffa M.

Inactive
Raffa M.
Tutor for more than 10 years (private and at University)
Tutor Satisfaction Guarantee

## Questions

### Subject:Trigonometry

TutorMe
Question:

Consider a triangle with the sides $$a$$, $$b$$ and $$c$$ and the angles $$\alpha$$, $$\beta$$ and $$\gamma$$ where $$\alpha$$ is the angle opposite of $$a$$ etc. We know that $$b = 5$$ $$cm$$, $$\beta = 90°$$ and $$\alpha = 36,87°$$ Calculate $$a$$, $$c$$, $$\gamma$$ and the area $$A$$ of the triangle.

Inactive
Raffa M.

To calculate $$\gamma$$ we use that for each triangle the sum of all angles equals $$180°$$. Therefore we know that $$\alpha + \beta + \gamma = 180°$$, so that $$\gamma = 90° - 36,87° = 53,13°$$ Since $$\beta = 90°$$ we have a right triangle. To calculate $$c$$ we use that $$\cos(\alpha) = \frac{c}{b}$$. Since we know $$\alpha$$ and $$b$$ we get $$c = \cos(\alpha)b = 0,8 * b = 4$$ $$cm$$ To calculate $$a$$ we can either use the angles again or the Pythagorean theorem (because we have a right triangle). Since $$b$$ is the side opposite to the right angle it is the hypotenuse in our triangle, so $$b^2 = a^2 + c^2$$. That means $$a^2 = \sqrt{b^2 - c^2} = \sqrt{25 - 16} = 3$$ $$cm$$. The formula for the area of a triangle is $$A = \frac{1}{2}gh$$ where $$g$$ is a side of the triangle and $$h$$ is the height of the triangle, perpendicular to $$g$$. In our example we can use $$a$$ as the height since it is perpendicular to $$c$$. We get for the area $$A = \frac{1}{2}ca = \frac{1}{2}4*3 = 6$$ $$cm^2$$

### Subject:Basic Math

TutorMe
Question:

Let $$a$$, $$b$$ and $$c$$ all be different from $$0$$. Solve for $$a$$: $$4a + 12,5b^2 = \frac{14}{3}ac + abc$$ What condition must be fulfilled for $$a$$ to have a solution?

Inactive
Raffa M.

At first we use equivalent transformations to bring all the terms with $$a$$ on one side: $$12,5b^2 = \frac{14}{3}ac + abc - 4a$$ Ultimately to solve the equation for a we need to have a result that looks like $$a = ...$$. All the terms on the right side of the equation contain $$a$$ but $$a$$ is not standing by itself. To get that we need to bracket $$a$$ out of the terms on the right side, so the right side will look like $$a(...+...+...)$$. In general to bracket $$x$$ out looks like that: $$xy + xy = x(y + z)$$. Doing that on the right side of our equation we get: $$12,5b^2 = a(\frac{14}{3}c + bc - 4)$$ Now the right side simply is $$a$$ times a number depending on $$b$$ and $$c$$. To have a standing alone we divide both sides by $$(\frac{14}{3}c + bc - 4)$$. Doing that we get $$a = \frac{12,5b^2}{(\frac{14}{3}c + bc - 4)}$$. For $$a$$ to have a solution the denominator of the fraction $$\frac{12,5b^2}{(\frac{14}{3}c + bc - 4)}$$ must be different from zero. If we look at $$(\frac{14}{3}c + bc - 4) = 0$$ and add $$4$$ on both sides to have an expression for $$b$$ and $$c$$ we get $$\frac{14}{3}c + bc) = 4$$. That means the denominator is different from zero if $$\frac{14}{3}c + bc) \neq 4$$.

### Subject:Calculus

TutorMe
Question:

What is the derivative of $$f(x) = \cos(x)\sin(x) + e^{\sin(x)}$$ ?

Inactive
Raffa M.

To determine $$f'(x)$$ we use the sum rule for $$f(x) = g(x) + h(x)$$, so $$f'(x) = g'(x) + h'(x)$$ and part the problem into two: At first we take a look at $$g(x) = \cos(x)\sin(x)$$. Here we have a product of two functions which means that we need to use the product rule to derive $$g(x)$$. As a reminder, the product rule says $$(u(x)v(x))' = u'(x)v(x) + u(x)v'(x)$$. We know that $$\cos'(x) = -\sin(x)$$ and $$\sin'(x) = \cos(x)$$. Therefore using the product rule we get $$g'(x) = \cos^2(x) - \sin^2(x)$$. Now we take a look at $$h(x) = e^{\sin(x)}$$. Here we have a composite function which means that we need to use the chain rule to derive it. The chain rule says: $$(u(v(x))' = v'(x)u'(v(x))$$. That means $$v(x)$$ is the inner function and $$u(x)$$ is the outer function. In our example $$e^x$$ is the outer function and $$\sin(x)$$ is the inner function. We know that $${e^x}' = e^x$$ and $$\sin'(x) = \cos(x)$$. Using the chain rule we get $$h'(x) = \cos(x)e^{\sin(x)}$$. Now using $$f'(x) = g'(x) + h'(x)$$ we get $$f'(x) = \cos^2(x) - \sin^2(x) + \cos(x)e^{\sin(x)}$$.

## Contact tutor

Send a message explaining your
needs and Raffa will reply soon.
Contact Raffa


text:
#### Volume 25, issue 7 (2021)

 Recent Issues
 The Journal About the Journal Editorial Board Editorial Interests Subscriptions Submission Guidelines Submission Page Policies for Authors Ethics Statement ISSN (electronic): 1364-0380 ISSN (print): 1465-3060 Author Index To Appear Other MSP Journals
Quot schemes of curves and surfaces: virtual classes, integrals, Euler characteristics

### Dragos Oprea and Rahul Pandharipande

Geometry & Topology 25 (2021) 3425–3505
##### Abstract

We compute tautological integrals over Quot schemes on curves and surfaces. After obtaining several explicit formulas over Quot schemes of dimension-$0$ quotients on curves (and finding a new symmetry), we apply the results to tautological integrals against the virtual fundamental classes of Quot schemes of dimension $0$ and $1$ quotients on surfaces (using also universality, torus localization and cosection localization). The virtual Euler characteristics of Quot schemes of surfaces, a new theory parallel to the Vafa–Witten Euler characteristics of the moduli of bundles, is defined and studied. Complete formulas for the virtual Euler characteristics are found in the case of dimension-$0$ quotients on surfaces. Dimension-$1$ quotients are studied on K3 surfaces and surfaces of general type, with connections to the Kawai–Yoshioka formula and the Seiberg–Witten invariants, respectively. The dimension-$1$ theory is completely solved for minimal surfaces of general type admitting a nonsingular canonical curve. Along the way, we find a new connection between weighted tree counting and multivariate Fuss–Catalan numbers, which is of independent interest.

However, your active subscription may be available on Project Euclid at
https://projecteuclid.org/gt

We have not been able to recognize your IP address 18.232.59.38 as that of a subscriber to this journal.
Online access to the content of recent issues is by subscription, or purchase of single articles.

or by using our contact form.

##### Keywords
Quot schemes, virtual classes, tautological integrals, virtual Euler characteristics
##### Mathematical Subject Classification 2010
Primary: 14C17, 14D20
Secondary: 14C05, 14J28, 14J80


text:
# DYNO eddy current brake. take 2!

Discussion in 'Performance Mods' started by HeadSmess, Jan 19, 2014.

right! the scrap yards open after the break, ive been paid for the last week of slavery, the pile of bills has shrunk, i can return to this project!

purchased, after much scavenging...one piece of brass (grrrrr, there wasnt any copper i could see that was suitable, alloy would have possibly been better anyway- and cheaper!) cut as a 8 " or so disc. there was a whole stack of them. i think theyre rejects because of the small nick in one edge (opposite my thumb) due to bad cutter programming...

also scored a nice 1:1 right angle drive

anyways! the plan!

bore hole in centre, trim edge, balance using a whipstick. (a long mandrel, held in chuck, disc at far end. mandrel rides in tailstock centre. spin it up with crayon held just off disc edge, back off tailstock centre just a touch, and disc will "wobble" and be marked at the heaviest point. drill out small spot of material, retest, repeat till perfect)

machine that alloy thingy as a hub with bearings. bolt to disc. probably better to balance it after all that, rather than just the disc. im planning on running this straight off the crank now

then get a steel plate, set it up on a bush so it can be slide back and forth along the shaft. cover the thing in neo magnets and by decreasing clearance between magnets and disc...achieve adjustable eddy current braking.

may end up silver soldering some brass strips to the back, to make a rudimentary fan. possibly two discs with the strips in between for a "slotted" rotor... getting too far ahead of myself now!

the disc with the magnets will be the stationary "torque" member.

yay. lenz law

now where to find some big neo magnets that are fairly cheap...

wow. a 4" X 1 " disc has 262 kg of pull! and costs about that much too! (oh yeah... one place i worked at, a client bought in his "fishing" magnets. they needed a permit because they CAN KILL YOU! "fishing" as in fishing out the auger that just fell apart 2 km down in a sand and water filled hole)

or a 12x5mm with 4kg of pull...20 pack for $42 sounds betterer...thats 240 kg or so of pull for$120

<
2. ### FabianWell-Known Member

HeadSmess, can you please expand on that story. It sounds """SO""" 'Dr Evil'

well, if you think that not many people can curl 100kg, let alone 240 kg concentrated in a 100mm diameter area... get that on your chest, and suddenly you discover that;

thats basically it the ones this guy had were 100 mm cubes! i think they were rated at around 1 tonne of pull! even need special delivery drivers and all that stuff. nasty things! credit cards? wiped from 2 metres

oh, and horizontal boring rigs are also deadly when something goes wrong

in this case, it was just the auger/reamer fell apart near the end of a hole. theres only one way to keep drilling to finish the job. get all those diamond insert filled lumps of steel out of the muck! a single blade weighed in around 150kg, so you needed something pretty good to drag them out of what was basically quicksand. well, big multi million dollar lawsuit and someone was fired... not me! id already walked by that point

guys on the oil rigs hate broken tips too....they have to lift kilometres of pipe VERTICALLY! can take months to clear a broken head...

4. ### FabianWell-Known Member

That's an unfathomable amount of magnetic attraction.
More interesting is how such magnets are made?

wiki would answer all that. all i know is that neo loses its power at a very low temperature...that could be a problem for what im doing what with radiant heat. meh. theres other types of magnets and i dont really think it will be an issue anyway. seems to be about 70c...

this guy was only able to transport his so freely cus they were already stuck to something... still powerful, but clinging like barnacles to a rock... kept clean as supplied and they jump to anything magnetic that gets too close. hence the danger. hmmm. barnacle cannon :wacko:

most magnets are sintered out of some collection of ground up goop. ferrite is basically cast iron, alnico is aluminium cobalt and nickel, neo is another weird collection again... pretty interesting how they build the super powerful magnets that make the superconductors look wimpy... a superconductor is used mainly because once the field is established it persists as long as its kept cold. while they do make strong magnetic fields...they arent the strongest.

dont ask me what makes a magnet do its thing but. bit like gravity and time, noone really knows...

money=progress.

25 magnets coming my way. 6.1kg pull each, or...4,200 gauss.

gives me about 100,000 gauss in total.

some spreadsheet calculator came up with figures of 400 amps in a 30cm conductor spinning at 5000rpm... 270 ft/lbs of force on a conductor carrying 400 amps in a 100,000 gauss field... . . . . . . . . . . . .

im pretty sure this will work? otherwise, i got some good fridge magnets...

25 neo magnets are freaking STRONG! without a good grip, theres no chance of pulling 6kg directly off a steel bench.

so, havent pulled the cover off the lathe yet, just played with magnets all last night...

the quick "swipe" past the previously pictured brass disc encountered serious resistance, with just one magnet... its why lenz law is a law...its always going to do it. and as ill be trying to do it with 25 magnets, at quite a few more RPM...

so. i guess i have to do some machining now!

8. ### FabianWell-Known Member

Still reading and still got my bag of popcorn beside me.

yay. i return, at last.

i finally machined up the disc. quite tricky really. involved shrink fits and mandrels and its good to practise such things.

so. i found a (dodgy) camera that works. has a pathetic mic. when i got it from fleabay it didnt work at all! maybe leaving them for a year helps? they have to ripen or something... :jester:

oh!

dodgy vid! ignore the date...

[video] http://youtu.be/-1g8bDLXNAQ[/video]

here you can see it does stop rather quickly. yes, its not safe yet! i can feel the braking force, iunno if the video shows it too well... but basically my hand stopping the magnets will be replaced with a set of scales and a torque arm... me will will be replaced with a bench, and a safety shield. be spinning it at crank speed! just a felixibke...wtf? flexible!! coupling:jester: between it and engine under test.

gotta find bearings with a larger ID, these are just old crank bearings... larger shaft, then find that PERFECT 10mm thick steel disc off the back of a speaker that i cant find... grrrr.... this is what happens i lose stuff too much junk! anyway. steel disc, ill machine with evenly spaced pockets to take the magnets. for now, a faceplate is good enough and just happens to slide on the shaft i have

length of runs will be determined by how hot the disc gets!

also buy a few hundred magnets perhaps...? they took up a lot less space than i expected...

need to experiment with the polarity of the magnets... alternating or monopole?

but.

it works neat-o

10. ### FabianWell-Known Member

only "better" bearing...6003 rather than 6202.. 17mm ID

hmmm....crank bearings huh?

Last edited by a moderator: Dec 15, 2015

i dont forget about things and i dont give up... i simply stop and ruminate for a while. life keeps getting in the way

found my lump of steel. just wanted to use it cus its nice and soft...magnetically and machining wise.

magnet disc...

fresh off the mill. obviously 24 neo magnets will sit in them there pockets. no need for glue. im never getting the one i stuck in so far back out!

ive decided the whole thing works better when the magnets are alternating in polarity. much better.

this just makes me realise how time can fly past...

tried writing a code so they would slowly spiral in rather than just be on the circumference, but other than rewrite a few thousand lines by hand, i had to put up with it. wont affect anything.

Last edited: Apr 27, 2014
13. ### 074KUMember

Looking very nice, I hope one day my machine work looks that good. I have been keeping an eye on this thread for a while now and can hardly wait to see the finished product in action.

cheers. tis the machine, but i take credit for using it and it took me a while to set it up.

next mill/lathe i buy, im getting a surface plate and doing some scraping. makes the world of difference on cheap chinese muck

you got me in the mood to go take pics of what i just made...

back. phone camera sucks

just the hub. very small spigot to centralise on. what you cant see is its 50mm of 90mm round bar at the back...(life getting in the way...set of carbide tools i bought were 2mm too high, so i decided i would machine all 50 at once...now i got all these lathe tools i can use . but i had to do at least one for this job) now for some holes on a pcd, some countersunk screws, and all i need is the shaft and adjuster doodad. that gets things to the rotating/loading point...

then some v block type clamp to hold the shaft steady. scales... grrrr. scales.

brrr. getting cold. meh. go rug up and drill some holes

15. ### 074KUMember

Sounds like you have it all planned out. I humbly volunteer to risk my ride for the sake of testing her when its all together :jester:
I think Fabian is going to be pounding on your door to give this little beaut a go. :grin5:
All joking aside I imagine it will be a very solid well built Dyno if your brake is anything to go by, Thank you for keeping us updated with all that sexy metal.

I think I am going to have to drag the wood heater into the workshop myself in the next few days, not enough light or warmth to keep up with my desire to mess about in the workshop, Women don't understand our sacrifices.

boring....

as the title says, today was boring, literally.

the part ive been dreading...the part i knew would take all day...9am to...its 4pm ish now

the spindle.

how to bore a 25mm hole 150mm deep? my 22mm drill bit has only 120mm of flute to use!

once that was over, the rest was easy. just wasting time with a finishing tool, nice slow feed whilst turning slow with a funny tool...

rightio..

erm. boring the hole. custom boring bar using a lump of old HSS endmill as a cutter

then we started getting all the rust off the outside...note the mandrel in the chuck for concentricity

old lord poobah here decided he wanted a nice smooth finish so made a funky tool... well, taking 4mm off in one pass with HSS is always ugly

first finin pass.

there is no final pass!

but... there is a finished...semi finished product

so. a long brass plug goes down the hole. it has a hole bored through it, tapped to M14x1 (just cus i have that size handy, saves doing an internal thread) and another hole at right angles at the far end.

this spindle i made needs the small hole tapped, firstly, to retain the disc.

then its getting a slotted hole down near the end.

the hole in the brass plug should line up with this slot.

the previously posted magnet disc, will have a bolt through it, engaging with the brass plug.

then a lead screw is stuffed down the end of it, threading into the brass plug.

so when i turn the handle, the magnet disc assembly will move towards or away from the rotor.

a whole freakin day...im going out and getting something to eat...

some number crunching, showing how easy this is in theory...

If torque and angular speed are known, the power may be calculated. The relationship when using a coherent system of units (such as SI) is simply

P = \tau \omega
where P is power, \tau is torque, and \omega is angular speed. But when using other units or if the speed is in revolutions per unit time rather than radians, a conversion factor has to be included. When torque is in pound-foot units, rotational speed (f) is in rpm and power is required in horsepower:

P \text{(hp)} = {\tau \text{(ft} {\cdot} \text{lbf)} \times f \text{(rpm)} \over 5252}
The constant 5252 is the rounded value of (33,000 ftÂ·lbf/min)/(2π rad/rev).

When torque is in inch pounds:

P \text{(hp)} = {\tau \text{(in} {\cdot} \text{lbf)} \times f \text{(rpm)} \over 63{,}025}
The constant 63,025 is the rounded value of (33,000 ftÂ·lbf/min) Ã— (12 in/ft)/(2π rad/rev).

seee if that posts properly, otherwise...

http://en.wikipedia.org/wiki/Horsepower

so.

lets say i have a foot long reaction arm. of course i will!

and my scales, in pounds, reads 10 when i load the thing down at 5000rpm....

so, take the equation...

10x5000/5252=

9.5hp.

rotational speed, measured torque...hp seasy

3.6 lb at 6500rpm? 4.45 hp...etc etc...

now, my only thinking bit at the moment is mounting this spindle...

so, i need the torque reaction from the magnet disc. i guess the easy way is to just make the slot slightly oversize and let the thing spin slightly on the shaft, is how ive been picturing it so far. other option is to mount the spindle itself on bearings, the slot is tight with minimal play, and the reaction arm is clamped to the spindle... lets me use plain old spring scales but i think a proper load cell is on the horizon...

18. ### FabianWell-Known Member

I like how you've sexed up your post with a bit of maths.

well, its there, it works. hmm. i gotta mount it on the lathe and take a video. anyways.

i was browsing just now and came across this...

http://atom007.heimat.eu/tmt/gsf_dyno.html

now, it might sound impossible, dyno an engine with just a microphone?

the explanation makes it clear. engine produces a given frequency at given rpm.

it takes so much power to accelerate a given weight to a given speed.

knowing the gear ratio and mass being moved, and the rpm, one can deduce the power required...

not catering in wind resistance which complicates the issue but hey...

stuck on a bench, testing the magnetos signal, rather than a mic...and just a heavy weight being accelerated, like an inertia dyno. one knows the mass, one knows the rpm, one knows the change in speed per second or acceleration...

so whyd i make this thing anyway? lol

20. ### 074KUMember

I like the look of that program, The wind resistance thing seems a bit of a pain.. Maybe just mount the rear wheel on some sort of freewheeling drum and strap the bike down with a load equal to riders weight and input 0 for the Cd value?

The rest of it seems fairly straight forward to produce, bit of veroboard, few components from Jaycar or the like, maybe a couple of spade terminals wired into the parallel with the CDI to allow quick and easy hookup if you felt like doing further dyno work.

Mount a Bicycle computer to the rear wheel, multiple magnets for more accurate reading as suggested..

May not be 100% accurate that way but should at least give enough information to determine if change X is "good" or "bad".

I dunno, I am just spitballing here.

All that being said I am still very keen to see how your project is panning out. 16:
May have to stick the bike on the ferry and come give it a whirl :laugh2:


text:
# Riemann sum help!!!!

by blahblah33
Tags: area, definite integral, integration, riemann, riemann sum
 P: 2 1. The problem statement, all variables and given/known data Use Riemann sum with ci= i3/n3 f(x)= $$\sqrt[3]{x}$$ +12 from x=0 to x=18 n= 6 subintervals Approximate the sum using Riemann's Sum 2. Relevant equations $$\Sigma f(ci) \Delta$$ xi is the equation for riemanns sum i think 3. The attempt at a solution i tried plugging in stuff using that, but i must've done something wrong because the answer i got was 200 off the actual area under the curve...
 P: 2 also, is my original equation for riemann's sum correct? is there a limit involved?

 Related Discussions Calculus & Beyond Homework 0 Calculus & Beyond Homework 3 Calculus & Beyond Homework 2 Differential Geometry 8 Calculus & Beyond Homework 7


text:
# Slow load of Mediawiki landing page in IIS8 using PHP, MySQL, FastCGI

• ### Question

• User-1602494344 posted

I've read a lot of posts regarding this issue where a PHP website (in my case Mediawiki), takes between 10 - 15 seconds to load when browsing the landing page for the first time in a session. While there are a lot of suggestions of configuring output_buffering in PHP, DNS resolution in MySQL, PHP caching using Wincache or APC, short of using Apache (which is not an option), I have yet to find a working solution. I have gone through every iteration of Mediwiki fine tuning, and to the best of my knowledge, fine tuning of MySQL, PHP and IIS. I don't believe that any of individual technology is causing the bottleneck, but I feel that the protocol interfaces between the different technologies (e.g PHP Manager for IIS, FastCGI, or URL Rewrite) could be the issue. I have tried to come at this from different angles, have upgraded hardware and used different servers with Server 2008 R2 and Server 2012, all with exactly the same result.

It's interesting to note that on both environments, with different OS' and hardware configurations (memory, RAID etc), the time to load is exactly the same - around 15 seconds. It's like there is a sequence of events that need to sequentially transpire in order for the site to finish loading. My setup is as follows:

1. Windows Server 2012 x64 with IIS 8
2. PHP v5.4.14 (x86) Non Thread Safe for compatibility requirements for Wincache
3. MySQL 5.5 (x64), administered with MySQL Workbench 5.2
4. Mediawiki 1.20.2

Additional information regarding my server components are:

• IIS URL Rewrite
• IIS PHP Manager
• IIS FastCGI
• Wincache enabled
• 8GB Memory with RAID 10 configuration

Not sure what else is relevant, but I'm hoping that there is a property or configuration that needs to be enabled that will provide the solution. All help is greatly appreciated, and I look forward to documenting the resolution.

Tuesday, July 23, 2013 2:18 AM

• User-1602494344 posted

Success!! I have been able to achieve the response times that I was looking for, without having to move off the Microsoft platform. To resolve this issue, I did the following:

1.  One of the biggest impacts, reducing the load from 15 seconds down to around 6 or 7 was to enable Mediawiki caching and acceleration, as detailed in this post: http://www.charlesrcook.com/archive/2012/09/12/mediawiki-iis7-output-caching-and-friendlyshort-urls.aspx. In short, enable the following in your Mediawiki localsettings.php file:

$wgCacheDirectory = "c:\your\path\to\cache";$wgFileCacheDirectory = "c:\your\path\to\cache ";
$wgEnableSidebarCache = true;$wgUseFileCache = true;
$wgShowIPinHeader = false;$wgEnableParserCache = true;
$wgCachePages = true;$wgMainCacheType = CACHE_ACCEL;
$wgMessageCacheType = CACHE_ACCEL;$wgParserCacheType = CACHE_ACCEL;
$wgMemCachedServers = array(); Make sure your local IUSR and IIS_IUSR accounts have "Modify" permissions on the cache directory, or else the files and directories from Mediawiki caching engine will not be able to write to them. 2. I made some minor changes to caching in PHP using Wincache, but that hardly had any affect - enable and configure it if you wish from a PHP perspective, but don't expect a major jump. The same thing goes for MySQL query caching - my Wiki site is relatively small, with minimum usage, so MySQL query caching wasn't a huge improvement. 3. The final nail in the coffin to bring the site up to speed was modifying the$wgDBserver setting in my Mediawiki LocalSettings.php file. It was set to "Localhost", and this post http://forums.iis.net/t/1153459.aspx/3/10 suggested that using "Localhost" on Windows 7 onwards, and Server 2008 onwards starts getting IPv6 involved in the querying of the page.  The transport layer had to resolve localhost and was doing so by negotiating between an IPv4 and an IPv6 address,  which PHP and MySQL needed to resolve before allowing the page to render. It appears that this is still not a fully supported integrated protocol, so setting \$wgDBserver to the IPv4 address of "127.0.0.1" took the rendering from 6 seconds to just on 1 second - problem solved!

Having IIS, Mediawiki, PHP and MySQL all on one Windows Server 2008 or Server 2012 does work, once the above settings are applied.

• Marked as answer by Tuesday, September 28, 2021 12:00 AM
Wednesday, July 24, 2013 2:17 AM


text:
# What is the distance between (-1,7) and (4,3)?

Dec 2, 2015

$d \left(A , B\right) = \sqrt{41}$

#### Explanation:

$A = \left(4 , 3\right)$ and $B = \left(- 1 , 7\right)$

Using the Euclidean distance

We have d(A,B)=sqrt((-1-4)^2+(7-3^2)

which is $d \left(A , B\right) = \sqrt{41}$


text:
# Is quantum computing a meme? All this talk and no one seems to achieve anything

Bidwell

Is quantum computing a meme? All this talk and no one seems to achieve anything.

idontknow

@Bidwell
Sure it's not Moore's law but we're making steady progress. This shit is not exactly easy.

The religion of bumping particles have absolutely no proof for any of their claims, they don't even know electrons exists still to this day. Why do you think that after spending x amount of billions of dollars on CERN, they only want to build an even LARGER one now?

Methnerd

Do quantum computers work if no one is observing them?

Sharpcharm

@idontknow
Who's we?

Snarelure

@Bidwell
All this talk and no one seems to achieve anything
yeah because it's really fucking hard.

Is quantum computing a meme?
Far from it. So quantum computing could be used to do a bunch of cryptography bullshit, but fuck that, the real application of quantum computing is molecular dynamics.

So it's really fucking hard to simulate molecules and shit. Figuring out where electrons is fucking hard man, but we need to do this so we can figure out what the forces in a molecule are. Most often we don't fucking do this because it takes like a goddamn long time to figure out where they are, like a day even for small molecules.

When we do, we just figure out where the electrons are once and assume they don't fucking change much, and then guess what forces are with fucking springs that approximate things. So instead of a molecule going zip-zop-bippity-bop, it just goes boinga-woinga-woing when we simulate it.

Well this fucking sucks because our simulations aren't that accurate. So if we want to simulate stuff moving around, well we need to figure out where the electrons are for each step. Simulations like this tend to take months and even then still aren't that accurate.

Quantum computing could let us figure out where the electrons are FAST. Like sonic fast, maybe even in minutes!

If we can do this shit fast we can figure out how to make drugs, organic solar cells, new materials, and nanotech FAST! This will change the world a heck of a lot more than the government being able to decrypt all your anime porn.

Skullbone

oh man that's great bait, have a (you). I lel'd

Burnblaze

@Sharpcharm
Humanity

SniperGod

Do you see the delusion of the atomists belief that electrons and a "negative" charge exist? They believe that magical bumping particles are what nature works on which is hogwash. "Really fucking hard" is more like "really fucking impossible" because THEY AREN'T THERE. All it is is a perturbation of (ether, energy, atom, whatever you want to call it) a force and the magnitude it causes.
Quantum quacks were clueless as to what the double slit experiment resulted in, if they had just done it with water drops they would have realized what "electrons" really are.
Pic related

LuckyDusty

Yep, modern science has turned into utter nonsense. Trying to describe the non-physical, physically. Stick to the physical or don't call what you're doing science, it's more conceptual logic than anything.

Crazy_Nice

@Bidwell
quantum "computer"
literally just a tube

hairygrape

@Crazy_Nice
Well most computers just look like boxes. It's what is on the inside that counts

@SniperGod
@LuckyDusty
Are you guys trolling or just retarded

Techpill

@hairygrape
what is it

PurpleCharger

No, that's the funny part! Not only is there no proof of electrons, but there's also no proof of protons or neutrons either! Gravitons, thiston, thatton, whateverton are all THEORETICAL "particles" that somehow work in this "Quantum glue" or whatever the fuck they're calling it nowadays.
Also there is no proof of "dark matter", "anti matter" or any other such nonsense. Everything in the universe is charge and discharge via pressure mediation.

Nojokur

@PurpleCharger
How do you explain the Millikan drop experiment? What predictions does your model make that differ from conventional subatomic theory that would allow us to test it?

iluvmen

The oil does not conduct electricity as well and the charge created changes the electomagnetic permitivity in the chamber. The xray creates the waveform perturbations to cause the oil drops with a lower electric permeability to "float" or slow down.

@Bidwell
Seriously how are quantum computers supposed to work in principle?
Like qubits represent multiple bits as a superposition and it does all its calculations at once, but then to get an answer you have to collapse the qubit solution to a single bit state anyway so what was the point?

Techpill

@iluvmen
I feel like you're not understanding the point of the Milikan drop experiment. It provides tremendous evidence for the quantization of charge, which is a key property we identify with electrons. How does your theory resolve the fact that charge comes in integer multiples of some small unit charge?

Methnerd

@PurpleCharger
There's no proof of protons, neutrons or electrons
What the fuck

TreeEater

Fuck, this is why Veeky Forums is my favourite board.

Sharpcharm

Like qubits represent multiple bits as a superposition and it does all its calculations at once, but then to get an answer you have to collapse the qubit solution to a single bit state anyway so what was the point?

There's a couple really clever algorithms that can extract some really useful information and collapse the superposition in a way that gives you some information about all the answers. These are really rare though, only the quantum fourier transform and the search algorithm run faster on quantum computers. Aside from that, there is quantum simulation.

BlogWobbles

He could then switch on the electric field, and adjust it so that the electric force just precisely balanced the force of gravity on the drop.

Gee I wonder why. Also, in this article I am not seeing how this relates to an electron being a particle, all I see is a description of Coulombs which is just a unit of measurement. Where does the fucking electron come from? A fantasy dimension?
@Methnerd

I know right? You'd think that explanations would be given instead of descriptions when talking about bumping particles, but no. You get no "source" of where they come from, according to quantum physics they just "come out of nowhere" or "phase in and out of reality"

TechHater

@Snarelure
fucking

JunkTop

@Bidwell
no one seems to achieve anything
Probably because you don't understand the material or follow its development.

https://en.wikipedia.org/wiki/Timeline_of_quantum_computing

haveahappyday

@Techpill
Some really cold stuff.

Techpill

@Bidwell
I'm a retarded but I might be able to explain it.

So uh there was this article in like pcworld like ten years ago about how someone was using an organic material to store information and supposedly the read/write speed as well as the density are much better than typical computers. But who knows there are always those stories of new kinds of memory that store 15 tb on your microsized penis but anyway

Let's say you're trying to simulate some shit with a regular computer. Disregarding the fact that our universe itself is just a model of what's really there, when you work with a computer you build a model and do basic computations at ridiculous speeds to attain an approximation of what would really happen.

But when you use a medium of experimentation that more closely resembles the thing you're trying to model, it would hypothetically be much easier to attain an accurate approximation.

For example if you were to somehow use molecules themselves as a way to experiment on different ways to manipulate molecules naturally you'd have a model that would run at 1x the speed of what it would be like in real life. Now that sounds totally stupid for a great number of reasons. But essentially the idea is simply that we have perhaps developed the type of technology we have right now to the point of diminishing returns and that there are certain things in the realm of all things math that would much better be simulated via things other than binary code. If we did have a magic molecule manipulator it would basically be a simple machine that was really not a computer at all but removed the need.

So the idea with quantum computing is just taking be advantage of the different mechanisms that influence how things behave on a quantum level. Imagine if we had an outline of how something would behave, such that we could simply refer to that outline as opposed to doing calculations.

SomethingNew

@Bidwell
what is the tube

DeathDog

@Bidwell
quantum people want you to believe that the slit experiment duality shows that photons are everywhere all at once. sounds stupid right?
nobody would give them money to research that.
but what if we could use that principle to destroy all encryption and spy on everyones emails.
i wonder who would give them money to do that. everyone?
so does it work or not?
well they haven't managed yet.

BinaryMan
Firespawn

@Snarelure
quantum computing is molecular dynamics
Takes one to simulate one. Is there anything to be learned?

TechHater

@TechHater

Evil_kitten

@Firespawn
did you read any of that? I'm saying that quantum computers could allow us to do the quantum chemistry fucking fast.

Now let's go back to what I actually said:
the real application of quantum computing is molecular dynamics.
@TechHater
Go fuck yourself. Here I'll help:
>>>/hm/

Boy_vs_Girl

@BinaryMan
give me a quick rundown on dilution refrigerators

Are they the only thing that can be used to cool quantum computers?

Lord_Tryzalot

@Snarelure
quantum computers
breaking synchronous encryption
No

AwesomeTucker

@Snarelure
Quantum computing could let us figure out where the electrons are FAST. Like sonic fast, maybe even in minutes!
How?

Illusionz

goddamn i'm going back to /pol/

JunkTop

@Bidwell
Lrn2meme fgt pls

Crazy_Nice

@Snarelure
Quantum computing could let us figure out where the electrons are FAST. Like sonic fast, maybe even in minutes!
How do you know this for sure?

Gigastrength

god bless this mess

Sharpcharm

@Sharpcharm
This, quantum computers only perform better if they're running algorithms made for a quantum computer. Otherwise it's the same performance of a classical computer.

RumChicken

@BlogWobbles
You get no "source" of where they come from, according to quantum physics they just "come out of nowhere" or "phase in and out of reality"

So god created those particles?

Nude_Bikergirl

@Bidwell
Is quantum computing a meme? All this talk and no one seems to achieve anything.

Is electrical computing a meme? All this talk and no one seems to achieve anything.

likme

@Crazy_Nice
Literally just a tube
You're literally just a tube dude, think about it.

PackManBrainlure

@Snarelure
DAE love typing a bunch of FUCKING swear words on the internet because it makes them feel like a FUCKING adult? FUCK yeah.

RavySnake

@Snarelure
delusional

Dreamworx

@AwesomeTucker
@Crazy_Nice
Everything takes minutes, especially if you allow for fractional and large numbers of them.

Google has partially demonstrated that this can work:

@PackManBrainlure
@RavySnake
You have no fucking clue how goddamn awesome it would be to do computational quantum chemistry orders of magnitude faster.

kizzmybutt

There are no "particles". The closer you look the more parts show up. It's not a simulation, nor a spontaneous creation. It always was by necessity, this is why the "0" argument exists. SOMETHING cannot be derived from NOTHING with any mathematical formula. In fact math is just an expression based on how accurately we can observe and record things, it means nothing when trying to figure out a question like that.
The closest example I can give you is a hologram:

I would like anyone here to explain to me how this works

You can cut a hologram into as many piece as you like and they will all show the same image. Kinda like how you can divide a magnet into a million pieces and they will all have their own separate magnetic fields. That is because there is no difference between the two, it is the same thing force causing both things to happen.

How far we can look into depends on how much more qualitative our instruments and technology becomes.
@Nude_Bikergirl
Where does the quantum computer get the ability to manipulate these alleged particles? Other particles? Lol. I suppose you think a particle accelerator can work without electricity and magnetic fields too right?

Illusionz

@Bidwell
I don't think it's a meme.
I'm not an expert but let us try to think this through.
Computing can be understood on our macro scale
Computing does things, and has its limitations which are derived from its properties on a macro scale
Quantum things do things that can be understood only on a quantum scale.
quantum computing does computing things whose limitations are derived from quantum properties

Nude_Bikergirl

@Bidwell
The problem is that all achievements have big consequences but since no one has made it cheap to make, affodable, and integrated into already functioning systems it isn't going too far.

Snarelure

@kizzmybutt
So it's not a simulation, and it's not created by god?
Then what is our universe?

MPmaster

I never said it wasn't created by God. I said that it goes on forever and never stopped nor started. the closer you look with better technology the more parts appear. Physicists think they're seeing quantum particles when all they're seeing is smaller turbulence resulting in smashing turbulence together.

But really all it is is pressure mediation, in the form of space and counter space. This DOES exist and we utilize that to make energy/evolve/cause every phenomena know to man and the universe and comes in the form of a toroidal/hypertroidal centrifuge. This is why every single equation we have only measures a rate of change etc. We could never come up with equations for "atoms at rest" or "photons at rest" because there is NEVER any object "at rest"quite simply because of the right hand rule, everything always must be moving in such a chaotic, but simplistic as a whole fashion. An "expression" could be used, but not a mathematical absolute.

You don't have "negative" and "positive" charge, you have "charge" and "discharge". The only thing that makes atoms and elements appear and act different is because they have a different arrangement of these hold fasts that act like rubber bands. Snap one and they'll snap the next and so on.
Space and counter space are not one thing in of themselves, but one side of the same coin. This is also why "free energy" and perpetual machine cannot last forever, because you can only take energy from where it is to where it isn't, not create it out nothing.In this system you're essentially moving energy out of everything in the universe via induction and the magnitude of said induction only peters out into infinitesimally small turbulence on a grand scale.

And that is a good thing because if we were to create "free energy" we would essentially be creating another universe every time we use energy. "Nowhere" cannot exist so to create energy would be creating "something" to take it from.

SniperGod

It really is hard to conceive of, but it is basically a yes and no kind of answer. Take another holographic type of equation like the Fibonacci sequence. There is a "math formula", but it's really an expression. The problem is that you need the previous number because it's a recurrence relation. You cannot make a "math formula" for the Fibonacci sequence to find the "Nth" term because eventually you'll run into a limitation of the formula. You would have to calculate to the end of phi to figure out the true answer, something that HAS NO END.

RavySnake

@MPmaster
@SniperGod
IS THIS PSEUDOSCIENCE?

CouchChiller

@MPmaster
I said that it goes on forever
but the universe is expanding
also entropy

there has to be an end

or will there be a big crunch?

FastChef

This thread is quite a spectacle
It's hard to tell if you've finished, but if not then please continue

New_Cliche

@RavySnake
@CouchChiller
Entropy in what? Expanding into what? A system that always gets smaller and smaller and larger and larger? Why do you think more powerful magnets have a smaller magnetic field? Why do you suppose lasers become more powerful the more concentrated they are? Why are computers more powerful now and able to calculate better then when they were large boxes with tapes in them? Engines? Motors? You would think that bigger things have more energy right? They do not. Smaller things have more COHERENCY, thus you're directing the energy that's already there more and more efficiently.

How can a thing end when it never started?

Spazyfool

they don't even know electrons exists still to this day

@New_Cliche
But more powerful magnets have larger magnetic fields.

And also- actually, I don't think I can even begin to untangle this. Carry on user.

Evilember

@kizzmybutt
something cannot be derived from nothing with any mathematical formula

Hmm. What about $\delta E \delta t \geqslant \frac{\hbar}{2}$? This formula describes that energy can be "created from nothing", albeit for very, very short periods of time.

Flameblow

Help me understand where you are coming from.

There are no atoms / particles / whatever, and what we perceive as matter is just a result of energy being projected through a medium?

New_Cliche

@TechHater

Nojokur

@haveahappyday
actually it's some really hot stuff that they're desperately trying to cool down

BinaryMan

@Evilember
albeit for very, very short periods of time

@Spazyfool
No proofs, all theories. Please prove me wrong. Go ahead and mention Millikan oil drop experiment and I will be glad to tell you that it would not have produced the results without the xray or the electromagnet, the experiment would not have produced the result it did.

@Flameblow
There are no atoms / particles / whatever, and what we perceive as matter is just a result of energy being projected through a medium.

Via induction coherency, permeability, permittivity, and the LOSS of inertia AKA change, yes. All projected via magnetism!

No they really don't. Go take a n45 and a n55 Gauss magnet and record the distance which one can grip and the n45 will grab further away. The n55 Gauss magnet will hold strong yes because MORE INDUCTION, was passed through it. Size doesn't matter it's the RATE OF INDUCTION in the magnet.
Compare it to a gyroscope. When you speed up the gyroscope it wants to remain in one spot because it's mass has become COHERENT. You can nudge it, and it will try it's best to remain straight and will take up less spacial foot print. When it starts losing that momentum what happens? It wobbles, you can tip it and it'll start to shift around and precess more, it will take up MORE spacial footprint because it has a LESS COHESIVE mass.

What would have more gravity? An Earth sized Earth or an Earth sized sun? Both have the same about of mass, but there is one key difference. THE RATE OF INDUCTION OF THAT MASS.

PurpleCharger

@BinaryMan
@Flameblow
(You)

There are no atoms / particles / whatever, and what we perceive as matter is just a result of energy being projected through a medium.

Via induction coherency, permeability, permittivity, and the LOSS of inertia AKA change, yes. All projected via magnetism!

So this implies that we could literally bring corporeal things into "existence" with the correct application of energy.

Ignoramus

Lunatick

@PurpleCharger
Correct, but correcting the "existence" part with "moving existence" with the application of energy, the magnitude of which can never be comprehended or measured...

@Ignoramus
yes, but that would be counter space with everything connected to each other, not just "special snowflake particles".

Lord_Tryzalot

@Lunatick
the magnitude of which can never be comprehended or measured...

god did it with his thoughts alone

obviously god is an alien being with access to technology we can only imagine

CouchChiller

@Lord_Tryzalot
No, any such being would be constrained by it's own creation. Something that has no common measurement would mean there is no such technology in the universe exists to conjure it's existence, only to manipulate it based on it's past alone and it's future approximated with an expression (which is just a guess).

FastChef

@CouchChiller
Just to clarify I was talking about aliens and their technology, not God. God much like what I just stated has no common measurement. You could say that only an omnipotence like that could create what we cannot by the limitations of what is logical to us.
In any case we're doomed and blessed at the same time by such a system; we can have fun with it, but cannot create or destroy it by its design.

Inmate

@Evilember
This formula describes that energy can be "created from nothing",
no it doesnt

Methnerd

@kizzmybutt
it's a brainlet who doesn't know shit about math tries to make an argument by waving his hands around grade-school math he learned from an alcoholic single mother teacher who dropped out of college
really taking my noggin' for a joggin' ain'tcha?

Carnalpleasure

@BinaryMan
Okay so what happens when we die?
Is there an afterlife?

StonedTime

@Evil_kitten

BunnyJinx

@Flameblow
I think he might have watched "spirit science" with all the bullshit about toroidal stuff. Spirit science is made by some guy thats making youtube videos while he is, presumably, high. You really have too watch a video to believe that its possible to spout so much nonsense at once.

@BunnyJinx
why is it bullshit though?

SomethingNew

Well I think it is worth entertaining. After all it would make sense for everything to be fractal. We might be looking at smaller and smaller particles forever.

Also, we think of particles because it is something that seems tangible, where in reality it is probably not tangible. Perhaps a bridge between science and mysticism makes more sense.

CouchChiller

@Bidwell
It's a meme insofar as people thinking its going to make all PCs super fast
it isn't

@Bidwell
Yes and no, but mostly yes.

You see quantum computers have a error rate because parts of the system are effected by uncertainty. So most setups have a secondary sever farm to double check the data integrity. The faster and more powerful quantum computers have a higher error rate.

So the "best" quantum computer people brag about amount to flipping a coin really really fast then sending that random data to a lot of regular super computers to correct it. In which case the quantum computer doesn't really matter much.

There are some application specific quantum computers that work more like dominions, where the computer is carefully setup to simulate one specific problem and then collapses to find the solution. These types have been show to be helpful in solving the specific problem they were built to solve. But they are very complex and only built to solve one problem, which can still be worth the trouble in limited cases. But that is not how people typically think of computers. So that type is more like running a simulated experiment.

Bidwell

@Methnerd
Is so arrogant and stubborn that he can't contemplate nature being as simplistic as possible so he thinks that Math (a human language) can explain it.

I haven't even used an iota of math to describe something so simple that even math proves by not being able to prove that it isn't true. Math is a limitation.
Please enlighten me how math explains how the universe works and I will tell you that YOU'RE WRONG. There is no equation that explains it, they only measure a rate of change, nothing EVER stays still in the universe. Usually these equations are accompanied by this inconvenient thing called an "expression". I'm sure you see where I'm going with this so I won't jog your noggin' too hard.

@Carnalpleasure

Methshot

@Bidwell
the purpose of math is to describe reality
thanks for confirming you don't know shit about math, babby
i wish you'd stop posting like you knew anything about anything but i know you wont

Raving_Cute

@Methshot
Well it sure as hell can't EXPLAIN IT EITHER. When you DESCRIBE SOMETHING you state what you OBSERVE based on your PERSPECTIVE. To record these observations in our PERSPECTIVE we use MATH. So yes we use math to aid in understanding the reality we live in. BUT.
When you have an EXPLANATION you already know how it works, it is understandable. You do not need math to explain anything.

What do you think math is since you're obviously an expert

BinaryMan

@Raving_Cute

t. associate math prof

@Methshot
Yes that kind of thinking is why we have grown physicists talking about "virtual particles" and other made up bullshit tailored to fit specific mathematical formula.

haveahappyday

@Nojokur
Pretty sure quantum computers use like no energy but they just have to keep them cold to stop the atoms from moving around or something.

Techpill

Still avoiding the question. I now honestly believe that I know more math than you since you can't even tell me what it's used for.
Are you learning it just to become a teacher or something? If so then it doesn't surprise me that you can't even answer a basic question.

Skullbone

@AwesomeTucker
@Crazy_Nice
Basically, all quantum systems can be described with essentially the same maths. E.g. any 2-level system is can be modeled as a spin-1/2 particle etc. Because of this, if you set up a quantum computer to be (approximately) analogous to another quantum system you can just let it evolve and say with some confidence that the real system will behave in a similar way.

This is hard to do.

TalkBomber

@Techpill
I now honestly believe that I know more math than you since you can't even tell me what it's used for.
Mathematics can be used to describe reality but that's not the only thing it does.

Things like cryptography are pretty much entirely abstract but you still need maths.

TurtleCat

@Methnerd
Kek

VisualMaster

@Methnerd
Yes, they literally don't work if someone is measuring them.

Harmless_Venom

not the only thing it does

it also DESCRIBES abstract things.

So we're back to square one again. Please tell me how math is anything other than a description.

massdebater

@Bidwell
Any thing with Quantum- before it is a meme...

JunkTop

@PurpleCharger
no proof of antimatter
we're not allowed to call non- or low radiating matter and non- or weakly interacting matter dark matter because I say so
Sure hope this is is bait.

whereismyname

Can you physically build a Quantum Computer using a Quantum Computer?

@Bidwell
meaning what?
also how do you know this for sure
you literally don't

Evil_kitten

@Bidwell
No it's not a meme. Actually USC is doing good research in such topic:

Illusionz

Lets call the same thing something completely different for no logical reason other than the fact that our tools are not technologically advanced enough to see what's really going on.

I will call it like it is because quantum physics literally states so with words such as "theory", "proposed", or any other description that amount to "lol we don't know either". There have been NUMEROUS experiments involving the creation of absolute zero and NON of them have done so, nor have they had a reading of absolute zero in space. Why is that important you ask? That tells me something that should be quite obvious even to the most casual of observers, in that "empty space doesn't exist because there is matter and EM radiation which IS NOT NOTHING circulating throughout it. I'm not degrading my understanding by taking someone's word for it, that's for group thinking retards who can't think for themselves. When they can start throwing EXPLANATIONS around then maybe it will peak my interest, but right now they're basically meme tier as far as I'm concerned.

Wikipedia(not just wikipedia mind you):

"Dark matter is a hypothetical type of matter distinct from baryonic matter (ordinary matter such as protons and neutrons), neutrinos and dark energy. Dark matter has never been directly observed; however, its existence would explain a number of otherwise puzzling astronomical observations."

And that is their argument for every particle they have made up. "Oh we don't know what this similarly acting force is when you do x to it, put it in x coordinates, charge it with electricity, throw it into space, etc... . Why don't we do all those things to it and then say that each individual result is a modality that doesn't interact with the other! Each individual result have their own set of rules even though they're all affected by this incommensurable equilibrium!"

Quantum physicists are insane.

Lord_Tryzalot

meaning that no matter how many drugs you took, how many beauty products you used, how many people you fucked or how much money you made, the result is the same. Your corpse will be buried or your ashed burned, you will recycle into the earth as carbon and water or a critter won't starve for a couple days. There will be nothing left but the magnitude of memories in your loved ones lives, but eventually that will go to.
Where you go from there I cannot tell you, but I can tell you that as a being of matter, you are also subject to it's laws.

TL;DR: We'll all find out some day.

BunnyJinx

@Illusionz
Oh, I see. This entire thread, you've been speaking in the language of quantum field theory, haven't you? No wonder everyone thinks you're crazy.
Personally, I don't know how widely accepted QST is, but I'm sure it's not as quack as it sounds on the surface.
I will say you're wrong about not using math. Math is all about communicating explanations. Without math, you can never have a workable explanation. Even if everything really is just waves and rates of change, you can still describe that mathematically.
Remember, the universe follows it's own rules, whatever they may be. The fact that perpetual motion machines can't exist is proof of this. Therefore, there is a method underpinning the madness, which means it can be grasped and understood. If it can be understood, it can be described mathematically. That's what quantum field theorists are trying to do.


text:
# [Tex/LaTex] wrong with the \begin{definition}

pdftexundefined

I am completely new in LaTeX. I wrote this below code in TeXworks but it doesn't work:

\documentclass{article}
\usepackage{amsthm}
\begin{document}
\section{Introduction}
In this section I introduce some concepts which we need to fully understand the Ellipsoid method.
\begin{definition}
A set $S\in \mathbb R^n$ is said affine set if for every $x,y \in S$ and every $\lambda in \mathbb R$ we have $\lambda x+(1-\lambda )y\in S$.
\end{definition}
\end{document}

Very simple: there is no definition theorem-like environment by default. There's only a ‘definition’ theorem style. So here is how to define it, numbered by section:

\documentclass{article}
\usepackage{amsthm, amssymb}
\theoremstyle{definition}
\newtheorem{definition}{Definition}[section]

\begin{document}

\section{Introduction}
In this section I introduce some concepts which we need to fully understand the Ellipsoid method.
\begin{definition}
A set $S\in \mathbb R^n$ is said affine set if for every $x,y \in S$ and every $\lambda \in \mathbb R$ we have $\lambda x+(1-\lambda )y\in S$.
\end{definition}

\end{document}


text:
# Jordan normal form options from minimal polynomial

what is the Jordan normal form options from this minimal polynomial 𝑚𝐴(𝑥) = $𝑥^3 − 2x^2$. 4X4 matrix

I know of course that the 2 eigenvalues are 0,2.

• Can you tell what the algebraic multiplicities and geometric multiplicities of the two eigenvalues are? – Ted Shifrin Jul 8 '18 at 17:43
• if i knew that i won't ask the question , need to find all the possible options. – Bentzi Rozen Jul 8 '18 at 17:44

The characteristic polynomial is a multiple of the minimal polynomial, and they have the same irreducible factors, we face only two possibilities: $$\chi_A(x)=x^3(x-2),\quad\chi_A(x)=x^2(x-2)^2.$$
• ok , i also get it , but what about the jordan form , we need geometric multiplicities , its right to say that for the first one with $x^3$ the possible geometric multiplicities is 3,1 2,1 or 1,1 ? – Bentzi Rozen Jul 8 '18 at 18:01
• For the case with $x^3(x-2)$, there are are only two possible Jordan normal forms. Check which is a root of the minimal polynomial (this shouldn't be long with a product by blocks). – Bernard Jul 8 '18 at 18:24


text:
# zbMATH — the first resource for mathematics

LTL with arithmetic and its applications in reasoning about hierarchical systems. (English) Zbl 1415.68144
Barthe, Gilles (ed.) et al., LPAR-22. 22nd international conference on logic for programming, artificial intelligence and reasoning, Awassa, Ethiopia, November 17–21, 2018. Selected papers. Manchester: EasyChair. EPiC Ser. Comput. 57, 343-362 (2018).
Summary: The computational bottleneck in model-checking applications is the blow-up involved in the translation of systems to their mathematical model. This blow up is especially painful in systems with variables over an infinite domain, and in composite systems described by means of their underlying components. We introduce and study linear temporal logic with arithmetic (LTLA), where formulas include variables that take values in $$\mathbb{Z}$$, and in which linear arithmetic over these values is supported. We develop an automata-theoretic approach for reasoning about LTLA formulas and use it in order to solve, in PSPACE, the satisfiability problem for the existential fragment of LTLA and the model-checking problem for its universal fragment. We show that these results are tight, as a single universally-quantified variable makes the satisfiability problem for LTLA undecidable.
In addition to reasoning about systems with variables over $$\mathbb{Z}$$, we suggest applications of LTLA in reasoning about hierarchical systems, which consist of subsystems that can call each other in a hierarchical manner. We use the values in $$\mathbb{Z}$$ in order to describe the nesting depth of components in the system. A naive model-checking algorithm for hierarchical systems flattens them, which involves an exponential blow up. We suggest a model-checking algorithm that avoids the flattening and avoids a blow up in the number of components.
For the entire collection see [Zbl 1407.68021].

##### MSC:
 68Q60 Specification and verification (program logics, model checking, etc.) 03B44 Temporal logic 68Q45 Formal languages and automata
Full Text:


text:
featuresCount order sam file?
1
0
Entering edit mode
4.4 years ago
noeD ▴ 100

Hello!

I am using featuresCount for read summarization, with the following command:

featureCounts -T 5 -t exon -g gene_name -a genomehg38.gtf -o counts.txt file.sam

I am wondering if I had to sort by name my sam file before to use featureCounts. I have read the featuresCount's documentation but I didn't understand it.

Best

featuresCount RNA-Seq gtf sort • 2.8k views
2
Entering edit mode

It would be helpful for you to understand how featurecounts works if you tried both the options. Try it with and without sorted sam and let us know if it makes any difference.

From here ,

Due to internal requirements of featureCounts (ie., since it only counts feature hits if both read ends align to the same feature), these coordinate-sorted BAM input files are detected by the featureCounts binary and name-sorted prior to processing. Name-sorting occurs by featureCounts itself (as part of the binary), on a single core and in the current working directory.

1
Entering edit mode

Thank you! I have tried now and the results were the same :) Thank you again!

0
Entering edit mode

Thanks @noeD

2
Entering edit mode
4.4 years ago
h.mon 33k

No, you do not need to sort by name, although it needs either position or name sorted sam / bam. From the manual, page 29:

Automatically detect input format (SAM or BAM).

Automatically sort paired-end reads. Users can provide either location-sorted or name- sorted bams files to featureCounts. Read sorting is implemented on the fly and it only incurs minimal time cost.

0
Entering edit mode

I apologize in advance for the stupid question... but what you mean with "No, you do not need to sort by name, although it needs either position or name sorted sam / bam"? I tried the tool without providing other files and it works, but I would like to be sure that it is the right procedure. Thank you for your kindly help!

0
Entering edit mode

How did you get your sam file? Did you sort it, or know if the mapper sorts it on the fly? And what do you mean by

I tried the tool without providing other files

What other files? You only need the gtf annotation and the sam / bam mapping file.

0
Entering edit mode

It is the result of the alignment by HISAT 2... I didn't re-order it after that and I don't know if the mapper sorts it on the fly...

1
Entering edit mode

I don't think it does. You may want to try samtools sort on the HiSAT2 output.

0
Entering edit mode

I have tried to use featuresCount sorting the read and without doing it... I obtained the same result...


text:
# Chapter 4 - Applications of the Derivative - 4.9 Antiderivatives - 4.9 Exercises: 35

$${x^4} - 3{x^2} + C$$

#### Work Step by Step

\eqalign{ & \int {\frac{{4{x^4} - 6{x^2}}}{x}dx} \cr & {\text{split the numerator}} \cr & = \int {\left( {\frac{{4{x^4}}}{x} - \frac{{6{x^2}}}{x}} \right)dx} \cr & = \int {\left( {4{x^3} - 6x} \right)dx} \cr & {\text{use power rule for indefinite integrals}} \cr & = 4\left( {\frac{{{x^4}}}{4}} \right) - 6\left( {\frac{{{x^2}}}{2}} \right) + C \cr & {\text{simplify}} \cr & = {x^4} - 3{x^2} + C \cr & {\text{check by differentiation}} \cr & {\text{ = }}\frac{d}{{dx}}\left( {{x^4} - 3{x^2} + C} \right) \cr & = 4{x^3} - 6x \cr}

After you claim an answer you’ll have 24 hours to send in a draft. An editor will review the submission and either publish your submission or provide feedback.


text:
#### ${{\mathit \Xi}^{0}}$ MASS

The fit uses the ${{\mathit \Xi}^{0}}$, ${{\mathit \Xi}^{-}}$, and ${{\overline{\mathit \Xi}}^{+}}$ masses and the ${{\mathit \Xi}^{-}}−{{\mathit \Xi}^{0}}$ mass difference. It assumes that the ${{\mathit \Xi}^{-}}$ and ${{\overline{\mathit \Xi}}^{+}}$ masses are the same.
VALUE (MeV) EVTS DOCUMENT ID TECN  COMMENT
 $\bf{ 1314.86 \pm0.20}$ OUR FIT
$1314.82$ $\pm0.06$ $\pm0.20$ 3120
 2000
NA48 ${{\mathit p}}{}^{}\mathrm {Be}$, 450 GeV
• • We do not use the following data for averages, fits, limits, etc. • •
$1315.2$ $\pm0.92$ 49
 1972
HLBC
$1313.4$ $\pm1.8$ 1
 1968
HBC
References:
 FANTI 2000
EPJ C12 69 Precision Measurement of the ${{\mathit \Xi}^{0}}$ Mass and the Branching Ratios of the Decays ${{\mathit \Xi}^{0}}$ $\rightarrow$ ${{\mathit \Lambda}}{{\mathit \gamma}}$ and ${{\mathit \Xi}^{0}}$ $\rightarrow$ ${{\mathit \Sigma}^{0}}{{\mathit \gamma}}$
 WILQUET 1972
PL 42B 372 The Masses of the ${{\mathit \Xi}}$ Hyperons
 PALMER 1968
PL 26B 323 Precision Measurement of the ${{\mathit \Omega}^{-}}$ and ${{\mathit \Xi}^{0}}$ Masses


text:
## ordinal numbers list

List of Ordinal Numbers in Latin. As to numbers 20-90, remove the y, and add -ieth for ordinal numbers. Ordinal number; a number defining the position of something in a series, such as ‘first’, ‘second’, or ‘third’. K prezentaci je přiložen pracovní list pro žáky, který obsahuje cvičení z … And as you may have guessed, the numbers in this set end with 31st because the intention was for the ordinal number to be paired with Months of the Year and Days of the Week flashcards for practice with dates. Also, you must use a hyphen (-). Use our lovely resources to teach year 1 & 2 students about what ordinal numbers are. ; Ordinal numbers refer to a position in a series. Ordinal numbers. This is a fantastic bundle which includes everything you need to know about ordinal numbers across 28 in-depth pages. Wollen Sie online Englisch lernen? Ordinal numbers in German are set up in a particular fashion. Year. Below is a list of the Cardinal Numbers and Ordinal Numbers in Irish. For example: My first car was white, but my second car was red. ; Any ordinal name that doesn't end in st, nd, rd (as in "first", "second", or "third"), ends in th. An Ordinal Number is a number that tells the position of something in a list, such as 1st, 2nd, 3rd, 4th, 5th, etc. * In American English zero is used.. 1.1.5. They only show rank or position. For numbers in between 20-100, we use the ordinal number ending in -gésimo or -agésimo + the unique singular ordinal number 1-9, as in vigésimo primero (21st). Numbers in words: The ordinal numbers 1st → first, 2nd → second and 3rd → third are irregular. These are used as the base from which to form all the ordinal numbers between twentieth and ninety-ninth. Created Date: 7/1/2015 3:34:06 PM Add th to the cardinal number to form the ordinal number: six → sixth. Ordinal numbers. They include: When talking about dates in Polish; When talking about the time (for example when saying something is "1 o'clock" = godzina pierwsza. Ordinal Numbers Divisible by Ten. As you view the chart, keep in mind that all of these ordinal numbers can be written together or apart, as in decimoprimero or décimo primero . Latin Ordinal numbers tell the order of things in a set: first, second, third, etc. List of Ordinal Numbers in Irish. Testen Sie einfach gratis unsere Französischkurse. Os ordinal numbers (números ordinais) são números utilizados para indicar ordem ou hierarquia relativamente a uma sequência.. No inglês, a formação dos números ordinais é diferente da formação dos ordinais em português: apenas o último número é escrito sob a forma ordinal. An ordinal indicator is a character, or group of characters, that follows a number denoting that it is an ordinal number, as opposed to a cardinal number.. For English speaking countries, this corresponds to the suffixes -st, -nd, -rd, -th in written ordinals (represented either on the line 1st, 2nd, 3rd, 4th or as superscript, 1 st, 2 nd, 3 rd, 4 th).. The first use of ordinal numbers is to describe the order of objects, often written in the “figure” form. Numbers list in English. Pages in category "Ordinal numbers" The following 48 pages are in this category, out of 48 total. 25,798 Downloads . Irish Ordinal numbers tell the order of things in a set: first, second, third, etc. Ordinal numbers. I am twenty years old. Ordinal Numbers. English Numerals - things to remember . The ordinal numbers can be written using numerals as prefix and adjectives as a suffix, for example, 1st, 2nd, 3rd, 4th, 5th, 6th and so on. For example, the ordinal number of 1 is first, 2 is second, and 3 is third. Today is his nineteenth birthday. cardinal: 80 = eighty -> ordinal: eightieth = 80th ; cardinal: 90 = ninety -> ordinal: ninetieth = 90th ; Full article: how to write out ordinal numbers in words in (US) American English, using letters instead of numerals Here there are a couple of the main ordinal numbers, from 1st up to 19th, you can find a longer list in the full article: Englische Grammatik-Tipps mit Gymglish. The following diagram shows ordinal and cardinal numbers from one to twenty. An ordinal number is a number that indicates position or order in relation to other numbers: first, second, third, and so on.Author Mark Andrew Lim defines ordinal numbers: "Ordinal numbers do not represent quantity, but rather indicate rank and position, such as the fifth car, the twenty‐fourth bar, the second highest marks, and so on," (Lim 2015). Luckily there's only a small amount of numbers you have to learn. Ordinal Numbers. We have a wonderful range of engaging resources from pirate-themed display posters, to worksheets, interactive PowerPoints, activities, games and ordinal number stories to teach your students how to find ordinal numbers. Ordinal numbers are numbers that represent place or position. Ordinal Numbers Worksheets. Below is a list of the Cardinal Numbers and Ordinal Numbers in Latin. We also use ordinal numbers to talk about dates. Das Verständnis der Grammatik ist für das Verständnis einer Sprache entscheidend. My first friend is a student. Copyright © Mathseeds and Blake eLearning 2015 79 Number sense Lesson 63 • Worksheet 4 Check Name Ordinal numbers. By sakura A WS to learn vocabulary about the seasons, the names of the days and months, and ordinal numbers. Define ordinal numbers: ordinal numbers are numbers denoting an item’s place in a series. We use ordinal numbers to talk about the "order" of things or to define a thing's position in a series. There are many situations and sentences where you will need to use ordinal numbers. Use of Ordinal Numbers. This is a list of some countable ordinals in increasing order.. 0, the least ordinal; 1, the least successor ordinal $$\omega$$, 1st transfinite ordinal $$\omega+1$$, 1st transfinite successor ordinal $$\omega2$$, 2nd transfinite limit ordinal $$\omega2+1$$, 1st successor ordinal after the 2nd transfinite limit ordinal
ordinal numbers list 2021


text:
Address 1501 Farmerville Hwy, Ruston, LA 71270 (318) 255-2555 http://www.csruston.com

# histogram error Goldonna, Louisiana

Warning: NOT YET PROOFREAD Here's a moderately common problem: you make a bunch of observations of data, falling into some buckets or bins in a histogram, and maybe they have different Retrieved from the Connexions Web site: http://cnx.org/content/m16298/1.11/ ^ a b c Scott, David W. (1992). However, bins need not be of equal width; in that case, the erected rectangle is defined to have its area proportional to the frequency of cases in the bin[3] The vertical Best wishes, Ted. -------------------------------------------------------------------- E-Mail: (Ted Harding) Fax-to-email: +44 (0)870 094 0861 Date: 03-Nov-05 Time: 15:45:35 ------------------------------ XFMail ------------------------------ Previous message: [R] How to calculate errors in histogram

Ripley, Modern Applied Statistics with S (2002), Springer, 4th edition. Histogram Errors Neat example of how to think the right way in maths Return to top Please note this site uses cookies, and your consent is assumed if you continue to The message of the formula we found is that N, not Nk, is what describes 'how much data' we have collected in working out the bin total. Yep.

These two are of the same order if h {\displaystyle h} is of order s / n 1 / 3 {\displaystyle s/n^{1/3}} , so that k {\displaystyle k} is of order N. Neural Computation. 19 (6): 1503â€“1527. Skip to content User Menu User Login Register with suchideas.comInformationRegistering with our User Community enables you to access even more...Join now for free!

As you can see, this will have an effect of somewhat "flattening" the histogram, and of smoothing irregular variation from bin to bin. Based on your location, we recommend that you select: . doi:10.1002/wics.54. ^ Nancy R. A histogram can be thought of as a simplistic kernel density estimation, which uses a kernel to smooth frequencies over the bins.

Let Sk be the sum of all weights of the observations/events lying in this bin, Now here we have two sets of random variables - Nk is the number of observations doi:10.1093/biomet/66.3.605. ^ https://maikolsolis.wordpress.com/2014/04/26/optimizing-histogram-cross-validation/ ^ Freedman, David; Diaconis, P. (1981). "On the histogram as a density estimator: L2 theory". Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences. 186: 343â€“414. Comparing to the next bin, the relative change of the frequency is of order h / s {\displaystyle h/s} provided that the derivative of the density is non-zero.

For each data-point xi, with associated dxi, and for each bin j, use this to compute the "probability" pij that a point with mean xi and "error" dxi should fall into So instead of thinking about our Nk weights Wj, let's think about N weights, Nk of which are the original Wj, and the rest of which are... Hence typically, when this ratio is fairly small, the larger source of error is determined by whether .) Application to the histogram problem In the histogram problem, we can easily come Look up histogram in Wiktionary, the free dictionary.

Consider first the mean of the random sum X1 + ... + XM. Data by proportion Interval Width Quantity (Q) Q/total/width 0 5 4180 0.0067 5 5 13687 0.0221 10 5 18618 0.0300 15 5 19634 0.0316 20 5 17981 0.0290 25 5 7190 Then the histogram remains equallyÂ»ruggedÂ«as n {\displaystyle n} tends to infinity. Zeitschrift fÃ¼r Wahrscheinlichkeitstheorie und verwandte Gebiete. 57 (4): 453â€“476.

Freedmanâ€“Diaconis' choice The Freedmanâ€“Diaconis rule is:[18][10] h = 2 IQR  ( x ) n 1 / 3 , {\displaystyle h=2{\frac {\operatorname {IQR} (x)}{n^{1/3}}},} which is based on the interquartile range, Then, finally, we use similar formulae for M to recover From this, and the above expression for the expectation of the sum, we have our answer: which you probably wouldn't have If s {\displaystyle s} is theÂ»widthÂ«of the distribution (e. So can we avoid this mess altogether?

Pisani, R. Plugging this into the boxed formula above, we get ... The expected number of the N which might "really" be in bin j is then Ej = sum(P[,j]) and its variance (assuming that the "errors" in the xi are independent of D.

MathWorks does not warrant, and disclaims all liability for, the accuracy, suitability, or fitness for purpose of the translation. I need this for a curve fitting > algorithm. > > I have seen many crude ways of working out the error in each bin based > on the bin count Rare events - Poisson distribution In accordance with the so-called law of small numbers or the law of rare events (or more formally, the Poisson limit theorem), if the probability of This leads to the common practice in high energy physics etc.

This is likely due to people rounding their reported journey time.[citation needed] The problem of reporting values as somewhat arbitrarily rounded numbers is a common phenomenon when collecting data from people.[citation In a more general mathematical sense, a histogram is a function mi that counts the number of observations that fall into each of the disjoint categories (known as bins), whereas the Some theoreticians have attempted to determine an optimal number of bins, but these methods generally make strong assumptions about the shape of the distribution. If so, what algorithm does it use? > > 2) Could anybody please point me in the right direction (papers, books, > websites etc.) > > Thanks, > > -- >

Thus, if we let n be the total number of observations and k be the total number of bins, the histogram mi meets the following conditions: n = ∑ i = Nonetheless, equal-width bins are widely used. Remark A good reason why the number of bins should be inversely proportional to n 1 / 3 {\displaystyle n^{1/3}} is the following: suppose that the data are obtained as n This type of histogram shows absolute numbers, with Q in thousands.

OCLC682200824. ^ US 2000 census. ^ Dean, S., & Illowsky, B. (2009, February 19). A. (1926). "The choice of a class interval". Tips using a $1 bin width, skewed right, unimodal Tips using a 10c bin width, still skewed right, multimodal with modes at$ and 50c amounts, indicates rounding, also some outliers p.15.

Such Ideas.comCopyright: © Carl Turner & SuchIdeas.com 2009-2013 Home Articles Mathematics *Lucid* Journal Categories Info Contact Welcome to the site!