text:
• Create Account

## One Game World, Multiple Interfaces...

Old topic!

Guest, the last post of this topic is over 60 days old and at this point you may not reply in this topic. If you wish to continue this conversation start a new topic.

39 replies to this topic

### #21wodinoneeye  Members

1669
Like
0Likes
Like

Posted 15 January 2012 - 06:56 PM

One problem you will have to address is between the different roles (fps/rpg/rts) is how depedant they are and what happens when you cannot fill a role
at any point in time? If there is no strategic level player(s) is there anything to guide the lower roles and if no lower then the orders get carried out by dumb bots(or not at all)? If any role is placed by incompetant/uncooperative players (locally) do the other roles interacting in that locality have their game experience suffer?

Writing logic to competantly fill the roles when players arent available can be quite difficult.

Restrictions to prevent player abuse (force players to act as expected) can be monolithic or incomplete.

Doing such a game for 2 roles is usually difficult enough but with additional tiers that complicates making it work quite a bit more.
--------------------------------------------Ratings are Opinion, not Fact

### #22T e c h l o r d  Members

191
Like
0Likes
Like

Posted 16 January 2012 - 06:36 AM

One problem you will have to address is between the different roles (fps/rpg/rts) is how depedant they are and what happens when you cannot fill a role
at any point in time? If there is no strategic level player(s) is there anything to guide the lower roles and if no lower then the orders get carried out by dumb bots(or not at all)? If any role is placed by incompetant/uncooperative players (locally) do the other roles interacting in that locality have their game experience suffer?

Writing logic to competantly fill the roles when players arent available can be quite difficult.

Restrictions to prevent player abuse (force players to act as expected) can be monolithic or incomplete.

Doing such a game for 2 roles is usually difficult enough but with additional tiers that complicates making it work quite a bit more.

I'm a firm believer that all games should take advantage of Artificial Intelligence to fill in human-player gaps and perform repetitive tasks. However, Balance is always an issue in Multiplayer games with complex interactions and their solutions would game dependent. The impact to the world between the roles could be both explicit and implicit. I would speculate that its completely possible to develop such a game very few balancing issues especially if rules in place are very concise.

### #23Art Whiz  Members

194
Like
0Likes
Like

Posted 16 January 2012 - 09:25 AM

Hi TechLord. Even if I like your idea a lot, after thinking about it for a while, I don't see it working. First of all, what would be the Commander's role? And why would anyone listen to him? Besides, both the Commander and players must co-exist online at the same time to communicate and carry on tasks. I just don't see it happen...

You could think about it as to a Guild from WoW, except that Commanders have a top-view interface over the battlefield and tell players what to do, where to go... While this is nice in theory is kind of hard to implement in reality. That's just my point of view; it was not my intention to rain on your parade. I will be following this topic. ;)

♥♥♥ Legen... wait for it... dary Game Art for your every needs! ♥♥♥

### #24Morphia  Banned

101
Like
0Likes
Like

Posted 16 January 2012 - 12:59 PM

both the Commander and players must co-exist online at the same time to communicate

Why !?! What is sense in this : if one of them On-Line then he Drive Group (s) , if Both Commander On-Line then Drive of Groups is
Greatly !!

If not a have Humanity Player in game location ( GL ) then you will lancing NPC RTS player into your Groups , but then game
must consist AI tactical NPC : this is CompaRate ( CR ) with Automatically Battle fight .

Movement : light version especially endurance ChekPointS - first Vector1 of move Plus second Vector2 plus Next VectorN and
all of this Save in Massive and will have Matrix of MovementS - see as stanDarth method ))

Game Interface Manager ^|^ Deep Space Engineering

### #25ddn3  Members

1610
Like
1Likes
Like

Posted 17 January 2012 - 12:40 PM

I'm seeing a couple of powerful trends in gaming which have the potential to dominate the industry. I think this is one of them.

-Unified game world with multiple game "views" (Dust 514)
-Free to play everything with tiered service model (Battlefield Heros, Free Realms, etc..)
-Procedural worlds with strong physical modeling (Drawf Fortress, Minecraft, etc..)
-Open instanced multiplayer worlds, join anytime (Minecraft, Guild Wars, etc..)
-Cloud based gaming (Onlive, Gaikai, etc..)
-Casual gaming (web, mobile, social games etc..)

Of course they all have existing precedent but as time goes on, I think these models will start to dominate the gaming scene.

-ddn

### #26T e c h l o r d  Members

191
Like
0Likes
Like

Posted 18 January 2012 - 08:23 AM

I'm seeing a couple of powerful trends in gaming which have the potential to dominate the industry. I think this is one of them. -Unified game world with multiple game "views" (Dust 514) -Free to play everything with tiered service model (Battlefield Heros, Free Realms, etc..) -Procedural worlds with strong physical modeling (Drawf Fortress, Minecraft, etc..) -Open instanced multiplayer worlds, join anytime (Minecraft, Guild Wars, etc..) -Cloud based gaming (Onlive, Gaikai, etc..) -Casual gaming (web, mobile, social games etc..) Of course they all have existing precedent but as time goes on, I think these models will start to dominate the gaming scene. -ddn

Amazing!

ddn3, I've also recognized these trends which have subconciously inspired me to develop a Collaborative Cloud-based Game Development Platform that consolidates a Interactive Lobby, Content Creation Tools, Game Systems/Mechanics, Microtransactions, Marketing and Online Distribution into one a single product. The question I'm asked the most often is Do you think you can pull it off?

### #27ddn3  Members

1610
Like
0Likes
Like

Posted 19 January 2012 - 01:18 AM

I'm seeing a couple of powerful trends in gaming which have the potential to dominate the industry. I think this is one of them. -Unified game world with multiple game "views" (Dust 514) -Free to play everything with tiered service model (Battlefield Heros, Free Realms, etc..) -Procedural worlds with strong physical modeling (Drawf Fortress, Minecraft, etc..) -Open instanced multiplayer worlds, join anytime (Minecraft, Guild Wars, etc..) -Cloud based gaming (Onlive, Gaikai, etc..) -Casual gaming (web, mobile, social games etc..) Of course they all have existing precedent but as time goes on, I think these models will start to dominate the gaming scene. -ddn

Amazing!

ddn3, I've also recognized these trends which have subconciously inspired me to develop a Collaborative Cloud-based Game Development Platform that consolidates a Interactive Lobby, Content Creation Tools, Game Systems/Mechanics, Microtransactions, Marketing and Online Distribution into one a single product. The question I'm asked the most often is Do you think you can pull it off?

I think you can! I agree with your assessment and will also add that such a system would not just benefit "games" but any pro-creative act be it software engineering, pure mathematics, art, music etc.. Imagine a cloud based virtual environment where one programmer writes up a algorithm using visual forms much like legos, while his peers (separated by 100s of miles in the real world) review the construct, copying and improving, all source controlled and versioned. After they run and debug it they can post the entire process as an annotated YouTube video tutorial for others to learn from..

-ddn

### #28Morphia  Banned

101
Like
-1Likes
Like

Posted 20 January 2012 - 12:22 PM

Interactive Lobby

lobby for RPG character ?! if have the Chosen RPG-character ( as few NPC ) then may be lobby for One : Chosen One !! .
Game Interface Manager ^|^ Deep Space Engineering

### #29Morphia  Banned

101
Like
0Likes
Like

Posted 22 January 2012 - 02:55 PM

Multiplayers On-Line Hidden Objects ( very popular Style ... ) :

Game Interface Manager ^|^ Deep Space Engineering

### #30T e c h l o r d  Members

191
Like
0Likes
Like

Posted 23 January 2012 - 05:25 PM

Multiplayers On-Line Hidden Objects ( very popular Style ... ) :

My apologies Morphia, but, I don't understand what you're trying to get at.

One World, Multiple Interfaces is a design philosophy. I'm a big fan of Text-based gaming, especially web-based collaborative games. I enjoy text-based games so much that I'm integrating multiple text-only game engines (MUD, Interactive Fiction, Grid-Game and Action-Text) into my Super 3D Game Platform's Shell. A Command Line Interface (which also integrates IRC and Scripting Console). With S3GP Shell, Text Games co-exist on the 3D Client.

### #31Stormynature  GDNet+

4931
Like
0Likes
Like

Posted 19 February 2012 - 08:46 AM

One aspect you might give consideration to is the strong utilsation of clan/guild builds. Teamwork is often a core component of such situations which could lend itself to the discipline you would want for the larger scale activities.

### #32wodinoneeye  Members

1669
Like
0Likes
Like

Posted 24 February 2012 - 02:25 AM

I am looking at a design for a MMORPG based on a solo game (Bioshock) with at least 2~3 interface modes where there is :
1) a FPS interface (your gaming machine) for combats and exploring, and
2) a bunch of NPCs to order around to do the grindy stuff (help in combat too) - the RTS elements of rebuilding the ruined City the game is set in, and
3) the Tablet/Palmtop interface for minigames that have results in the main game, interplayer communications (mail, auction house, etc..) and some NPC task management.

You can find a series of posting covering it at :

http://irrationalgames.com/community/forums/bioshock-general-discussion/bioshock-first-person-mmo

http://rapturerebornmmorpg.wikia.com/wiki/Main_Page

which cover alot of different advanced aspects
(better NPC AI, modular object world instead of 'static' levels, auto-generation of parts of game world (terrain and quests), and player created assets)

Its all alot of features most companies (who are stuck in the WOW mentality) wont be touching for years leaving us in the backsliding feebleness most MMORPGs are today.

Edited by wodinoneeye, 12 May 2013 - 07:40 AM.

--------------------------------------------Ratings are Opinion, not Fact

### #33wodinoneeye  Members

1669
Like
0Likes
Like

Posted 24 February 2012 - 02:38 AM

Hi TechLord. Even if I like your idea a lot, after thinking about it for a while, I don't see it working. First of all, what would be the Commander's role? And why would anyone listen to him? Besides, both the Commander and players must co-exist online at the same time to communicate and carry on tasks. I just don't see it happen... You could think about it as to a Guild from WoW, except that Commanders have a top-view interface over the battlefield and tell players what to do, where to go... While this is nice in theory is kind of hard to implement in reality. That's just my point of view; it was not my intention to rain on your parade. I will be following this topic. ;)

I recall some two tiered game along time ago with 2 leaders of opposite sides and a bunch of player fighting.
The commanders coerced their minions into following orders by setting goals (markers/whatever) that awarded advancement when they were carries out.

I dont remember whatever came of that game. I wouldnt doubt they would need a way to almost instantly replace a commander who dropped out.

Likewise any large number of players trying to work together (in a coordinated way) needs a replacement system to feed in replacesments for anyone who drops out (which with 50 players would likely be one every 30 second the way people play these days).

Waiting for enough players even to gather is usually a problem and really needs to be some continuous thing with ad-hoc groups.
--------------------------------------------Ratings are Opinion, not Fact

### #34jefferytitan  Members

2508
Like
0Likes
Like

Posted 25 February 2012 - 06:15 PM

One possibility is that a particular game mode is almost like a specialisation. For example, if an RTS guy "harvests" an area it would yield say 50% of the material to be found there, but an RPG guy could manually check everywhere and get 100% of the stuff. Or an FPS guy could drive a vehicle, but it's FPS style and he doesn't have the options to change gears, upgrade the car, etc, so he's much slower than a dedicated racer. The racer could be a courier transporting stuff from town to town. An FPS guy could have a door hacking tool which is slow and/or sometimes fails, or a puzzle guy could be a dedicated hacker that other people can call on as required. He could also hack stuff that other players can't such as surveillance systems.

### #35Tinholt  Members

136
Like
0Likes
Like

Posted 25 February 2012 - 06:54 PM

Sorry for going a little of topic.

Let us say we do create such a world, wouldn't that at least need a better understanding of AIs and how they can interact with other players? I suppose we need a world that is working without anything holding it up, so if we give the player the option to opt in some kind of activity we can never assure that both sides will be equal without a waiting list (which could be killing if there is nothing else for the player to do/gain). AI should take on a more proactive role, instead of those which we say in many strategy games where it would just react when the odds are ever in his favor. Plus we must not forget the interaction of the player with the AI as non-enemy.

The problem with this kind of game is the capacity to entertain. Its quite easy to give everyone a job, however we don't want to annoy them by giving them tedious work that requires no effort whatsoever, no matter how big the pay offs are (for that the player uses cheats).

### #36jefferytitan  Members

2508
Like
0Likes
Like

Posted 25 February 2012 - 07:01 PM

Its quite easy to give everyone a job, however we don't want to annoy them by giving them tedious work that requires no effort whatsoever, no matter how big the pay offs are

Didn't you just describe an MMORPG? ;)

### #37Tinholt  Members

136
Like
0Likes
Like

Posted 26 February 2012 - 02:21 AM

Its quite easy to give everyone a job, however we don't want to annoy them by giving them tedious work that requires no effort whatsoever, no matter how big the pay offs are

Didn't you just describe an MMORPG? ;)

Let's take WoW for a most obvious example. You only do those dull daily quests so you get money/xp/whatever to make you richer before you start Raiding. Still nobody likes them.

### #38Sandman  Members

2210
Like
0Likes
Like

Posted 27 February 2012 - 04:39 PM

Morphia: please stop spamming this thread (or any other thread for that matter) with random, irrelevant videos.

Also, the rest of your posts are kind of hard to follow, and don't make a whole lot of sense. Perhaps a bit more time spent on the post itself and less time finding YouTube videos might help a bit?

### #39Pureaqua  Members

100
Like
0Likes
Like

Posted 01 March 2012 - 10:18 AM

Hy Techlord,
i have been thinking about such a multi-genre game as u describe it for a long time. I placed my idea in the sci-fi genre and thought of joinig RTS/FPS/Simulation. In short it would happen like raiding in wow. a group of people specialized in different areas would meet to achieve a common goal. in my case it would go a little bit like this. a battleship, carrying all players would enter a hostile solar-system to raid a planet. the Space-Admiral (RTS) would launch the fighters and protect the dropships heading for the planet. Arriving on the planet again a RTS player would start his normal routine with building his base/units to achieve his goal of e.g. protecting a digging site. The FPS player would actually choose what to do. either help the RTS as a hero unit, by his free will and only accepting orders if he wants to or go on his own mission. This missions would be e.g. infiltrate a underground compound and destroy generators which will slow down the response of the planets garrison by a big deal.
I also have come to believe that the two following points , imho, would be very important to be kept at anytime
- Players should be rewarded for playing together and helping each other. If the dont cooperate then the mission should still be fun for them individually.
- Even if all players but one drop the common game, it would still have to be possible for him to "go home" safely.

hope that this thread keeps fresh

### #40AltarofScience  Members

935
Like
0Likes
Like

Posted 03 March 2012 - 08:50 AM

Morphia: please stop spamming this thread (or any other thread for that matter) with random, irrelevant videos.

Also, the rest of your posts are kind of hard to follow, and don't make a whole lot of sense. Perhaps a bit more time spent on the post itself and less time finding YouTube videos might help a bit?

I always thought Morphia was a spam bot and wondered why it was never deleted. Is it an actual person? It just sounds like a bot and then it posts the videos.

Old topic!

Guest, the last post of this topic is over 60 days old and at this point you may not reply in this topic. If you wish to continue this conversation start a new topic.


text:
# What are the odds?

Let’s multiply together a bunch of numbers which are less than one and see how small they get!

If that sounds like fun, then you’ll love this sleek new infographic (of which the above is just the teaser) posted this morning at BoingBoing. The graphic is based on this blog post by Dr. Ali Binazir, who apparently has an AB (same as a BA) from Harvard, an MD from the UC San Diego School of Medicine, and an M.Phil. from Cambridge.

I’ll save you the effort of clicking through: the good doctor estimates the probability of “your existing as you, today”. His estimate consists of (what else?) multiplying a bunch of raw probability estimates together without conditioning! And I’ll give you a hint as to the conclusion: the odds that you exist are basically zero! Astounding.

I should add that it seems he was forced to add a disclaimer that “It’s all an exercise to get you thinking…” and (obliquely) admit that the calculation is bogus at the end of the post, however.

Is there any branch of mathematics which is abused so extravagantly as probability? I think these sorts of abuses are beyond even the most egregious statistical claims, no?

This entry was posted in Extralusionary Intelligence, Mathematics Basterdizations, Nitpicker's Paradiso, Off The Deep End. Bookmark the permalink.

### 15 Responses to What are the odds?

1. aram says:
2. John Sidles says:

Hmmm … wasn’t it Fermi who first asked “Where is everyone?”

And no-one’s complaining about his question. 🙂

A contemporary survey is Dave Waltham’s Testing Anthropic Selection: A Climate Change Example (Astrobiology 11(2): 105-114, 2011).

But c’mon … what’s the probability that climatic instability might induce planetary ecological collapse? It’s kinda nutty even to consider it! 🙂

3. Richard Gill, the statistician who relentlessly criticized the shoddy case against Lucia de Berk (the nurse Aram mentions), has also written thoughtful papers about quantum foundations and Bell inequalities.

4. There are 1146 characters in this post. They are all ASCII. The probability of this page is therefore (approximately) 1.4 times 10^(-2760). That seems highly unlikely. Therefore I do not believe in this post.

5. John Sidles says:

It’s desirable (IMHO) to distinguish between mockery of bad methods (which is OK) and mockery of good questions (which is less obviously a good thing).

The question asked is concretely “What are the odds?” and answers are sought that broadly illuminate any aspect of human existence in the Anthropocene.

So let us reflect — without much regard for comedic potential — whether “What are the odds?” is a good question?

As has already been mentioned, Enrico Fermi was among the first to ask it; subsequently von John Neumann considered it in his 1955 essay “Can we survive technology?” (answer: maybe); and nowadays we have thoughtful essays like James Hansen’s “The runaway greenhouse effect” (per the YouTube video of that title).

It is notable that in subsequent decades, the attempt to give serious answers to the Fermi/ von Neumann/ Hansen questions have engaged multiple themes of quantum physics. It is notable too, that the Pontiff of Rome (for one among many) has directed his Pontifical Academy to consider this general class of questions and answers in-depth.

Shall the Quantum Pontiffs follow the lead of Fermi/ von Neumann/ Hansen/ Benedict? What (if anything at all) does contemporary QIT have to say regarding “the odds” of present and future human existence?

If QIT is solely or mainly about mathematical analysis then perhaps the Magic Eight Ball’s sobering answers are appropriate: â€¢Â Reply hazy, try again â€¢ Ask again later â€¢ Better not tell you now â€¢ Cannot predict now â€¢ Concentrate and ask again â€¢ Don’t count on it â€¢ My reply is no â€¢ My sources say no â€¢ Outlook not so good â€¢ Very doubtful.   🙁

Yet if QIT is about more than proving theorems perhaps the Magic Eight Ball’s optimistic answers apply: â€¢ It is certain â€¢ It is decidedly so â€¢ Without a doubt â€¢ Yes — definitely â€¢ You may rely on it â€¢ As I see it, yes â€¢ Most likely â€¢ Outlook good â€¢ Signs point to yes â€¢ Yes!   🙂

• aram says:

True: there is a serious question about how to take an honestly Bayesian approach to hard questions like “how risky is this mortgage-backed security?” or “is there intelligent life on other planets?”

Challenges include model uncertainty, and the dependence of answers on the chosen prior, combined with the difficulty of formalizing the process by which we agree on a prior. These are great questions for science/social science/epistemology, and it’s true, I don’t have any great insights into answering them. But I can at least point out how not to approach them.

• John Sidles says:

That’s true, Aram. Golly, perhaps the empirical fact that the answer to Fermi’s question “Where is everyone?” is not known to be “Sleeping in our guest bedroom” can be construed as Bayesian evidence for $P \ne NP$.

The reasoning being that if $P = NP$, then galaxy-spanning universe-filling star-ships would be *easy* to design, eh? And so our visitors would already be here! 🙂

6. In related news: patent for compressing random sources http://gailly.net/05533051.html

The best part is: “It is commonly stated that perfectly entropic data streams cannot be compressed. This misbelief is in part based on the sobering fact that for a large set of entropic data, calculating the number of possible bit pattern combinations is unfathomable. For example, if 100 ones and 100 zeros are randomly distributed in a block 200 bits long, there are
200C100 = 9.055 10^58
combinations possible. The numbers are clearly unmanageable and hence the inception that perfectly entropic data streams cannot be compressed. The key to the present compression method under discussion is that it makes no attempt to deal with such large amounts of data and simply operates on smaller portions.” Brain. Explode.

• aram says:

Oh, I like that: the shorter blocks have larger fluctuations, so a larger fraction of them have low-entropy empirical distributions. You don’t need big savings; just asymptotically compress 1 bit to 0.999999 bits (in expectation) and then you can iterate. Can anyone see the flaw? 🙂

7. John Sidles says:

This Quantum Pontiff column inspires reflection upon the computational difficulty of essay-writing. Essays upon the general theme of dumbness, e.g. “Here is an egregious mathematical misunderstanding that is instantiated in a dumb patent” can be constructed efficiently via cherry-picking searches and lint-picking critical analyses; such essays are (computationally speaking) among the easiest to construct.

Essays upon the opposite theme “Here is a deep mathematical/physical insight that is instantiated in a foresighted patent” are tougher to construct (but why exactly?) and yet we feel instinctively that this class of topics too is interesting (but why exactly?).

Searching the intellectual property literature for historical names yields Norbert Wiener’s US#2024900, John von Neumann’s US#2815488, and Philip Anderson’s US#3335363. And there are more recent oddball patents like US#5307410 “Interferometric quantum cryptographic key distribution system” by some guy named Charles Bennett, and US#5768297 “Method for reducing decoherence in quantum computer memory” by Peter Shor.

There is even a pending application with the intriguing title “Physical realizations of a universal adiabatic quantum computer” (US#12/098,348) … presumably this application represents the nearest approximation that the present art allows to an enabling disclosure, and thus illuminates the pace of progress subsequent to the mid-90s patents of Bennett and Shor.

Bill GASARCH in his Computational Complexity weblog has taken to baldly predicting (in this week’s column for example) that “Quantum computers will never be practical.” A natural and important question for the Quantum Pontiff weblog to address is simply, is Bill right? 🙂

8. John Sidles says:

Stimulated in large measure by the ideas disclosed in Peter Shor’s 1998 patent “Method for reducing decoherence in quantum computer memory” (US#5768297), a panel of experiments met in January 2002 to produce version 1.0 of the now-celebrated “Quantum Information
Science and Technology Roadmap” (LA-UR-02-6900) whose concrete ten-year goal (page ES-1) was

“To develop by 2012 a suite of viable emerging-QC technologies of sufficient complexity to function as quantum computer science test-beds in which architectural and algorithmic issues can be explored.”

The QIST Roadmap called for test-beds to include (by 2012) the experimental demonstration of concatenated error-correcting codes on systems of 50 physical qubits.

There are only six weeks left on the 2002 QIST Roadmap, and so now is a natural time to review lessons-learned from the past decade 2002-2011, and perhaps begin conceiving roadmaps for the next decade 2012-2022. To my mind, such reviews are most useful when they are mindful of the advice of historian John Toland

“What follows is a factual saga [in which] the facts speak for themselves, and if any conclusion was reached, it was that there are no simple lessons in history, that it is human nature that repeats itself, not history. We often learn more about the past from the present, in fact, than the reverse.”

If the Quantum Pontiffs don’t review the past decade of quantum computing, who will? In the event that quantum computing does not review its past, are its future prospects diminished? Is the Fortnow/GASARCH weblog articulating an emerging scientific consensus when it predicts â€œQuantum computers will never be practicalâ€? Supposing that the “never practical” hypothesis is correct, then what should be the defining objectives and practical challenges of quantum information science?

These and similar questions are what I would like to see discussed here on The Quantum Pontiff.

9. John Sidles says:

As a concrete suggestion, perhaps during 2012 the Quantum Pontiffs might solicit guest-posts on the general theme “Ten Years After QIST” from the eighteen members of the 2002 QIST Experts Panel: David Awschalom, Carlton Caves, Michael Chapman, Robert Clark, David Cory, Gary Doolen, David DiVincenzo, Artur Ekert, P. Chris Hammel, Richard Hughes, Paul Kwiat, Seth Lloyd, Gerard Milburn, Terry Orlando, Duncan Steel, Umesh Vazirani, K. Birgitta Whaley, and David Wineland.

If versions 1.0 and 2.0 of the QIST Roadmap (documents LA-UR-04-1778 and LA-UR-02-6900 respectively) were over-optimistic with respect to the narrow objective of error-corrected quantum computing, these same documents were if anything under-optimistic with respect to the striking advances of the past ten years in our mathematical understanding of quantum coherence/decoherence, in our computational capabilities for simulating complex dynamical systems, and with respect to practical advances in strategically critical technologies like dynamic polarization, sensing, and spectroscopy.

It would be great to see these themes discussed on The Quantum Pontiff, with a view toward inspiring similarly striking advances in the coming decade.

10. John Sidles says:

Folks, there’s a memorable scene in the movie Apollo 13 in which flight engineer Sy Liebergot tells flight chief Gene Kranz: “Gene, the Odyssey is dying.”

To be blunt, the Theoretical Physics StackExchange is similarly at-risk: there are not enough questions, comments, and answers being posted to sustain a viable physics forum.

Is it really true that theoretical physics has too few questions and/ or too few people who care to ask/answer those questions, to sustain the Theoretical Physics StackExchange?

I’ve set myself the goal of asking/answering one or two physics questions a month; the point being that if every active researcher did this, the success of Theoretical Physics StackExchange would be assured … to the immense benefit (IMHO) of every active researcher.

My just-posted question for this month is “How does one geometrically quantize the Bloch equations?”. If you’ve got answers to this or any other physics question, please post-’em.

format: plain


text:
Tags
 IOS SQL HTML C RUBY-ON-RAILS MYSQL ASP.NET DEVELOPMENT RUBY .NET LINUX SQL-SERVER REGEX WINDOWS ALGORITHM ECLIPSE VISUAL-STUDIO STRING SVN PERFORMANCE APACHE-FLEX UNIT-TESTING SECURITY LINQ UNIX MATH EMAIL OOP LANGUAGE-AGNOSTIC VB6

# Does Nim support type inference?

By : Kristen Manila
Date : September 15 2020, 03:00 PM
this will help I saw this example in Nim, it requires explicit type specification for int and bool, although there's enough information to infer both (like TypeScript would do). , From the manual:
code :

Share :

## Why does Java not support type inference for constructors?

By : Sachin
Date : March 29 2020, 07:55 AM
seems to work fine This is a Java 7 improvement also known as the diamond operator. The syntax will be:
code :
List<String> strings = new ArrayList<>();

## Why does JDK Map.get not support type inference on the return value

By : user3494956
Date : March 29 2020, 07:55 AM
I wish this helpful for you Because it isn't (in general) safe to do this. A Map specifically declares that its values may be any type of Object, not just Foo, so in typical usage one should not be assigning its values to anything else. Doing so would be a programmer error usually, which the type system should (and does) help you avoid. If you want to do something like that, there's always casting, which makes your intent explicit.

## Does C# support type inference of the return type?

By : Μάριος Μιχαήλ
Date : March 29 2020, 07:55 AM
Hope this helps This is just a curiousity about if there is a fundamental thing stopping something like this (or correct me if there's already some way): , Because what would happen if you did this?
code :
static void M(int x){}
static void M(double x){}
static T N<T>() {}
...
M(N());

## Implicit parameters break type inference or inference does not suffice for their resolution?

Date : March 29 2020, 07:55 AM
Hope that helps The issue here is that scala cannot infer the O type because it is not present in Insert
code :
// I is in the parameter list but there is no O to be found
case class Insert[I, O](arg: I)(implicit evidence: Ordering[O])

scala> val i = Insert(3)
<console>:9: error: diverging implicit expansion for type Ordering[O]
starting with method Tuple9 in object Ordering
val i = Insert(3)

## Type inference:The initializer in the declaration is used to drive the inference engine,and is required

By : Amier Smith
Date : March 29 2020, 07:55 AM


text:
Archives

Testing equality of location parameters and quantiles of $S(\geq 2)$
by A. K. MD. EHSANES SALEH and K. M. HASSANEIN
Vol. 14 No. 1 (1986)
Contact with author not yet established; unable to provide full text.


text:
## higher order rate laws

$aR \to bP, Rate = -\frac{1}{a} \frac{d[R]}{dt} = \frac{1}{b}\frac{d[P]}{dt}$

Belle Calforda3f
Posts: 67
Joined: Fri Sep 29, 2017 7:07 am

### higher order rate laws

would Lavelle ever expect us to derive integrated rate laws greater than second order?

Danah Albaaj 1I
Posts: 50
Joined: Fri Sep 29, 2017 7:07 am

### Re: higher order rate laws

No, because as he has mentioned many times. We won't really be be involving ourselves with reactions that are more than second order due to their complexity.


text:
Dear Internet Explorer user: Your browser is no longer supported

Please switch to a modern browser such as Microsoft Edge, Mozilla Firefox or Google Chrome to view this website's content.

# Climate change: Is Australia serious?

I don’t believe Australia’s announcement of a 5% cut in greenhouse gas emissions goes far enough to prevent a climate change catastrophe.

Today Prime Minister Kevin Rudd announced that Australia will cut its greenhouse gas emissions by 5% of 2000 levels by 2020. If an international agreement were made, Australia could make a cut of up to 15%.

The announcement of such a low target has angered many in the community, who were expecting a much stronger response from Canberra . Like many Australians, I am also disappointed with the government’s weak emissions target.

Just last Saturday, the nations of the European Union announced that they would cut their greenhouse emissions by 20%, rising to 30% if an international agreement is reached. At the Climate Change conference in Bali in 2007, the Australian Government said it supported a 25-40% cut on 1990 emission levels by 2020. Now it seems that the government has changed its mind.

This announcement comes as a major disappointment, not just for Australia and for the environment but the new Labor government’s environmental credibility.

After 11 years of Liberal rule under climate change skeptic John Howard, there was an expectation that Labor would lead Australia to a dignified position on climate change. Indeed, Rudd’s first act as PM was to ratify the Kyoto Protocol, which earned Australia a standing ovation at the United Nations Climate Change Conference.

With today’s announcement, Rudd has effectively squandered Australia’s chance to make a real difference. After Mr. Rudd had personally declared that he wanted Australia to be a “creative middle world power“, today’s announcement suggests otherwise. Timidity on climate change will not put Australia in a leadership power position in Asia, let alone globally.

Nothing Australia can practically do in relation to climate change will prevent irreversible climate change, because our overall emissions are so small (1.2% of world emissions). Therefore, Australia has to demonstrate moral leadership, so that the big polluters – particularly India (4.9%), Russia (5.6%), China (18.4%) and the United States (22.2%) – will act upon the example that our nation sets. We’ve led the pack on tariff reduction and free trade, so why not carbon emissions?

Australia stands to lose more than many countries from climate change. The Great Barrier Reef will be completely destroyed, as will many other iconic natural wonders. Many of our agricultural districts will be more prone to drought and bushfires will become far more commonplace.

Those opposed to higher emission targets raise concerns about job losses. In some cases this is quite a legitimate concern, and governments need to plan around this to minimise the effects on individuals. That said, segments of Australia’s economy were subjected to pain when our tariff barriers were torn down and yet we all collectively recovered and later enjoyed the benefits of a lean and efficient economy. The only difference this time is that the subject of concern is far more serious. Whilst free trade could ultimately wait until all nations are ready, the climate can’t.

Australia needs to show real leadership on climate change, and do it now. Our nation needs to make a real commitment to reform, in order to convince the ‘big polluters’ to do likewise.

A paltry 5% emissions reduction target is nothing but a national embarrasement and demonstrates the Commonwealth Government’s lack of committment to the environment. It also shows the government’s contempt for younger Australians who will have to live with the consequences of this generation’s lack of foresight and leadership.

One response to “Climate change: Is Australia serious?”

On 27 January 2009, Shweta wrote:

Australia’s Climate Action groups from across Australia are heading to Canberra, encircling Parliament House on the first day of sitting. After Rudd’s pathetic announcement of 5% emission cuts for Oz, his failure to meet the bar at international negotiations, and \$4 Billion pledged in hard cash to the coal industry, it is clear that Rudd is not serious about climate change. That’s why it’s time to take mass community action.

This year is our ONE CHANCE to affect international policy. Failing that, we are saying goodbye to the world as we know it.

JOIN ME… or be as lame as Kevin Rudd.
http://www.climatesummit.org.au/

Event Details:
What: Australia’s Climate Action Summit
Where: Parliament House, Canberra
When: 8am, February 3, 2009

    <q cite="">


text:
# Legendre transformation

In mathematics, two differentiable functions f and g are said to be Legendre transforms of each other if their first derivatives are inverse functions of each other:

$Df=\left(Dg\right)^{{-1}}$

f and g are then said to be related by a Legendre transformation. Legendre transformations are named after Adrien-Marie Legendre. They are unique up to an additive constant which is usually fixed by the additional requirement that

$f(x)+g(y)=\left\langle x,y\right\rangle .$

The Legendre transformation is its own inverse, and is related to integration by parts.

## Applications

Legendre transformations are used in thermodynamics to transform between the different thermodynamic potentials, and in classical mechanics to derive Hamiltonian mechanics from Lagrangian mechanics, as well as the other way around.

## Examples

The exponential function ex has x ln xx as a Legendre transform since the respective first derivatives ex and ln x are inverse to each other. This example shows that the respective domains of a function and its Legendre transform need not agree.

$u(x)={\frac {1}{2}}\,x^{t}\,A\,x$

with A a symmetric invertible n-by-n-matrix has

$v(y)={\frac {1}{2}}\,y^{t}\,A^{{-1}}\,y$

as a Legendre transform.

## Legendre transformation in one dimension

In one dimension, a Legendre transform to a function f : R → R with an invertible first derivative may be found using the formula

$g(y)=y\,x-f(x),\,x=f^{{\prime -1}}(y)$

This can be seen by integrating both sides of the defining condition restricted to one-dimension

$f^{\prime }(x)=g^{{\prime -1}}(x)$

from x0 to x1, making use of the fundamental theorem of calculus on the left hand side and substituting

$y=g^{{\prime -1}}(x)$

on the right hand side to find

$f(x_{1})-f(x_{0})=\int _{{y_{0}}}^{{y_{1}}}y\,g^{{\prime \prime }}(y)\,dy$

with g′(y0) = x0, g′(y1) = x1. Using integration by parts the last integral simplifies to

$y_{1}\,g^{\prime }(y_{1})-y_{0}\,g^{\prime }(y_{0})-\int _{{y_{0}}}^{{y_{1}}}g^{\prime }(y)\,dy=y_{1}\,x_{1}-y_{0}\,x_{0}-g(y_{1})+g(y_{0})$

Therefore,

$f(x_{1})+g(y_{1})-y_{1}\,x_{1}=f(x_{0})+g(y_{0})-y_{0}\,x_{0}$

Since the left hand side of this equation does only depend on x1 and the right hand side only on x0, they have to evaluate to the same constant.

$f(x)+g(y)-y\,x=C,\,x=g^{\prime }(y)=f^{{\prime -1}}(y)$

Solving for g and choosing C to be zero results in the above-mentioned formula.

## Geometric interpretation

For a strictly convex function the Legendre-transformation can be interpreted as a mapping between the graph of the function and the family of tangents of the graph. (The tangents are well-defined at all but at most countably many points since a convex function is differentiable at all but at most countably many points.)

The equation of a line with slope m and y-intercept b is given by

$y=mx+b$

For this line to be tangent to the graph of a function f at the point (x0, f(x0)) requires

$f\left(x_{0}\right)=mx_{0}+b$

and

$m=f^{{\prime }}\left(x_{0}\right)$

f′ is strictly monotone as the derivative of a strictly convex function, and the second equation can be solved for x0, allowing to eliminate x0 from the first giving the y-intercept b of the tangent as a function of its slope m:

$b=f\left(f^{{\prime -1}}\left(m\right)\right)-m\cdot f^{{\prime -1}}\left(m\right)$

## Legendre transformation in more than one dimension

For a differentiable real-valued function on an open subset U of Rn the Legendre conjugate of the pair (U, f) is defined to be the pair (V, g), where V is the image of U under the gradient mapping Df, and g is the function on V given by the formula

$g(y)=\left\langle y,x\right\rangle -f\left(x\right),\,x=\left(Df\right)^{{-1}}(y)$

where

$\left\langle u,v\right\rangle =\sum _{{k=1}}^{{n}}u_{{k}}\cdot v_{{k}}$

is the scalar product on Rn.

Alternatively, if X is a real vector space and Y is its dual vector space, then for each point x of X and y of Y, there is a natural identification of the cotangent spaces T*Xx with Y and T*Yy with X. If f is a real differentiable function over X, then ∇f is a section of the cotangent bundle T*X and as such, we can construct a map from X to Y. Similarly, if g is a real differentiable function over Y, ∇g defines a map from Y to X. If both maps happen to be inverses of each other, we say we have a Legendre transform.

## Convex conjugates

### Definition

For a function

$f:{\mathbb {R}}^{n}\rightarrow {\mathbb {R}}\cup \{+\infty \}$

taking values on the extended real number line the Legendre transformation can be generalized to the Legendre-Fenchel transformation or convex conjugate of f by

$f^{\star }:{\mathbb {R}}^{n}\rightarrow {\mathbb {R}}\cup \{+\infty \}$
$f^{{\star }}\left(p\right)=\sup \left\{\left\langle x,p\right\rangle -f\left(x\right):x\in {\mathbb {R}}^{n}\right\}=-\inf \left\{f\left(x\right)-\left\langle x,p\right\rangle :x\in {\mathbb {R}}^{n}\right\}$

### Examples of convex conjugates

The convex conjugate of an affine function

$f(x)=\left\langle a,x\right\rangle -b,\,a\in {\mathbb {R}}^{n},b\in {\mathbb {R}}$

is

$f^{\star }\left(x^{\star }\right)={\begin{cases}b,&x^{\star }=a\\\infty ,&x^{\star }\neq a\end{cases}}$

The convex conjugate of the absolute value function

$f(x)=\left|x\right|$

is

$f^{\star }\left(x^{\star }\right)={\begin{cases}0,&\left|x^{\star }\right|\leq 1\\\infty ,&\left|x^{\star }\right|>1\end{cases}}$

The convex conjugate of the exponential function is

$\exp ^{\star }\left(x^{\star }\right)={\begin{cases}x^{\star }\ln x^{\star }-x^{\star },&x^{\star }>0\\0,&x^{\star }=0\\\infty ,&x^{\star }<0\end{cases}}$

### Properties of convex conjugation

Convex-conjugation is order-reversing: if fg then f*g*. The convex conjugate of a closed convex function is again a closed convex function. The convex conjugate of a polyhedral convex function (a convex function with polyhedral epigraph) is again a polyhedral convex function. For any proper convex function f and its convex conjugate f* Fenchel's inequality (also known as the Fenchel-Young inequality) holds:

$\left\langle p,x\right\rangle \leq f(x)+f^{\star }(p)$

The convex conjugate of a function is always lower semi-continuous. The biconjugate f** (the convex conjugate of the convex conjugate) is also the closed convex hull, i.e. the largest lower semi-continuous convex function smaller than f. Therefore, f = f** iff f is convex and lower semi-continuous.

## Further properties

### Scaling properties

The Legendre transformation has the following scaling properties:

$f(x)=a\cdot g(x)\Rightarrow f^{\star }(p)=a\cdot g^{\star }\left({\frac {p}{a}}\right)$
$f(x)=g(a\cdot x)\Rightarrow f^{\star }(p)=g^{\star }\left({\frac {p}{a}}\right)$

It follows that if a function is homogeneous of degree r then its image under the Legendre transformation is a homogeneous function of degree s, where 1/r + 1/s = 1.

### Behavior under translation

$f(x)=g(x)+b\Rightarrow f^{\star }(p)=g^{\star }(p)-b$
$f(x)=g(x+y)\Rightarrow f^{\star }(p)=g^{\star }(p)-p\cdot y$

### Behavior under inversion

$f(x)=g^{{-1}}(x)\Rightarrow f^{\star }(p)=-p\cdot g^{\star }\left({\frac {1}{p}}\right)$

### Behavior under linear transformations

Let A be a linear transformation from Rn to Rm. For any convex function f on Rn, one has

$\left(Af\right)^{\star }=f^{\star }A^{\star }$

where A* is the adjoint operator of A defined by

$\left\langle Ax,y^{\star }\right\rangle =\left\langle x,A^{\star }y^{\star }\right\rangle$

A closed convex function f is symmetric with respect to a given set G of orthogonal linear transformations,

$f\left(Ax\right)=f(x),\;\forall x,\;\forall A\in G$

if and only if f* is symmetric with respect to G.

### Infimal convolution

The infimal convolution of two functions f and g is defined as

$\left(f\star _{\inf }g\right)(x)=\inf \left\{f(x-y)+g(y)\,|\,y\in {\mathbb {R}}^{n}\right\}$

Let f1, …, fm be proper convex functions on Rn. Then

$\left(f_{1}\star _{\inf }\cdots \star _{\inf }f_{m}\right)^{\star }=f_{1}^{\star }+\cdots +f_{m}^{\star }$


text:
# Hypothetical Situation for sorting in $O(n)$ using median finding machine that works in $O(\sqrt{n})$

In a hypothetical world, we have a machine that can find median of $$n$$ numbers in $$O(\sqrt{n})$$. (Of course this machine is not real).

Can we use this machine to sort an array in $$O(n)$$?

I don't know how can I approach these type of questions which have a wrong statement as given. I know if the machine also partitions the array when finding the median, we can sort the array in $$O(n)$$ using $$T(n) = 2T(n/2) + O(\sqrt{n})$$.

But the question didn't say anything about partitioning. So if we assume that it doesn't change the array in any way and just finds the median, Can we use this machine to sort the array in $$O(n)$$ or not?

• Easy. Finding the median is $\Theta(n)$, therefore sqrt(n) >= cn, and since we can sort in O(n^2 / sqrt(n)), we can sort in O(n). – gnasher729 Jan 20 at 18:51
• "In a hypothetical world, we have a machine that ..." actually means that "We are given a hypothetical machine that ..., hence this world becomes a hypothetical world." That is, we can use whatever we can do besides using this machine. In particular, you can use the partition technique. – John L. Jan 20 at 21:18


text:
## sql server – SQL – global temporary table versus normal table

I have a stored procedure that I use to load csv files to SQL. Initially, this will massively insert the file into a global temporary table and then at the end it will do:

``````select cast(column1 as int) (column1), column2, column3... into table from ##temptable
``````

and then proceed to release the temptable ##

Before "selecting in the table from ## temptable" I run a series of selection queries in the temporary table to determine what the columns should be (and I'm sure this works correctly).

Note that having a table (normal or temporary) before creating the final output table is essential for the stored procedure.

What I would like to know is if it is better to use a global temporary table or if I should use a normal table or does it make no difference?

I have seen several articles on the differences between temporary tables and table variables, but I have not seen anything when it comes to comparing global temporary tables with normal tables and it is difficult for me to test this correctly in my environment.

## Temporary access to the page with URL sent to the email

I want to protect a certain page with a password. The problem is that I want to unlock it for users who have an active reservation (I am using WooCommerce reservations). I thought that a good idea could be to send an email to each user with an active reservation X minutes before the actual reservation begins with a private and temporary link to that blocked page. The link must use a token to unlock it automatically.
I don't know if this is possible in the WordPress environment.

Thank you!

## Algorithms – Temporary complexity of simple functions related to bits

A function `Pow` that calculates $$y = a ^ k$$ it occurs where $$k$$ is a
integer length $$n$$ bits:

``````function Pow(a, k)     { k >= 0 }
z := a;
y := 1;
m := k;
while m != 0 do
if m mod 2 = 1 then
y := y * z;
end if
m := m div 2;
z := z * z;
end while
return y;
end function
``````

Calculate the complexity of the weather in the worst case and the average time
complexity of this function. The dominant operation is a comparison
operation performed on line 6. Briefly describe the value of $$k$$ when
The worst case occurs.

So, I think the number of comparisons depends on the length of $$k$$ in terms of its bits.

Leave $$k = 0$$: (binary $$0$$ also what is $$1$$ little bit):

$$Rightarrow 0$$ comparisons

Leave $$k = 1$$: (binary $$1$$ also what is $$1$$ little bit):

$$Rightarrow 1$$ comparison

Leave $$k = 8$$: (binary $$1000$$ which $$4$$ bits)

$$Rightarrow 4$$ comparisons

Leave $$k = 15$$: (binary $$1111$$ which $$4$$ bits)

$$Rightarrow 4$$ comparisons

Leave $$k = 16$$: (binary $$10,000$$ which $$5$$ bits)

$$Rightarrow 5$$ comparisons

I think you can see a pattern.

Any set number $$2 h, 2 ^ h + 1, cdots, 2 ^ h + 1} – 2, 2 h + 1} – 1 } quad land quad h> 0$$, is $$h + 1$$ long pieces and therefore $$h + 1$$ comparison.

Then i think $$T_ {avg} (n) = T_ {worse} (n) = n in O (n)$$

But $$n$$ is the number of bits of $$k$$ number. Take function $$k$$ as a parameter, no $$n$$. So, my solution is not the desired one, I think.

In terms of $$k$$ I think it would look like this:

$$T_ {worse} (k) = lfloor log_ {2} (2k) rfloor in O ( log k)$$

$$T_ {avg} (k) = lfloor log_ {2} (2k) rfloor in O ( log k)$$

Questions:

1. It is the solution in terms of $$k$$ Right?
2. The solution in terms of $$n$$: How would you rate that, personally? Know the task description of the above.

I have published a similar thread in the mathematical stack exchange, but I would like to get more opinions on this from the CS experts themselves.

## python – Pyinstaller. Temporary files from the Datacompy package are not generated

I have made an application that uses Datacompy to compare two excel from the values of a column. In the console it works perfect for me, but when doing the .exe with pyninstaller (pyinstaller Main.py –onefile) and when executing the program, I get the following console error:

``````Exception in Tkinter callback
Traceback (most recent call last):
File "tkinter__init__.py", line 1705, in __call__
File "Main.py", line 45, in search_file
File "Main.py", line 66, in open_file_csv
File "site-packagesdatacompycore.py", line 445, in report
File "site-packagesdatacompycore.py", line 581, in render
FileNotFoundError: (Errno 2) No such file or directory:
``````

Thank you!!

## postgresql – Generating insert instructions for a table without creating any temporary tables

I can generate insert declarations for any table using the query

``````select 'INSERT INTO table values ('||id||', '''||currency||''')'
from testone ;
``````

But I want to include a where condition in it. So, is it possible to include conditions between them or is there an alternative way to generate the insertion instructions for a table by adding some conditions between them and without the need for a temporary table?

## shell: alternative to the temporary file in Bash

Some backup Blow The script on my machine copies the file names of specific directory entries into a text file.

Executing the script can gather existing names and find new ones, but then make sure that the names inserted in the backup file are sorted and unique.

``````local file=~/bar-entries.txt
touch "\$file" "\${file}_"
find ~/foo/bar -maxdepth 1 -type d ! -name bar | cat <"\$file" - | sort | uniq > "\${file}_"
mv "\${file}_" "\$file"
``````

Can this code be optimized? As if wondering if some Blow build or an external command could allow you not to trust a temporary file and edit the file instead.

## postgresql – How to design a unique table / index where uniqueness is temporary?

I have a table that records movies observed in a cinema:

``````CREATE TABLE cinema_movie_name (
id integer DEFAULT nextval('cinema_movie_name_id_seq'::regclass) PRIMARY KEY,
cinema_id integer NOT NULL REFERENCES cinema(id) ON DELETE CASCADE ON UPDATE RESTRICT,
name text NOT NULL,
movie_id integer REFERENCES movie(id) ON DELETE SET NULL ON UPDATE RESTRICT,
created_at timestamp with time zone NOT NULL DEFAULT now()
);

``````

Every time we see a new movie name in the cinema, we record it in this table and assign it to `movie_id` in our database.

The current singularity is applied in `(cinema_id, name)`that is to say

``````CREATE UNIQUE INDEX cinema_movie_name_cinema_id_name_idx ON cinema_movie_name(cinema_id, name);

``````

The problem is that for a long time, there may be several different movies with the same name, that is, after an arbitrary length of time `(id, cinema_id, name, movie_id)` It becomes invalid.

Therefore, I need to create an index that imposes a unique constraint on `(cinema_id, name)` Y `created_at` ± 3 months

How to create a unique index with a temporary column?

## Upload the file to s3 directly from drupal 8 instead of using temporary storage

I have a file upload form in drupal 8 where I am loading 3 different assets and they can be about 2 GB or more in size.
I have the s3fs module enabled and configured correctly, but due to temporary storage, it takes me a long time to load it into the web server. First it is loaded in the "/ tmp" directory and then in "s3". I also modified the Apache configuration to handle large file uploads.

Is there any way to speed up this charging process?
If possible, how to get the properties of the loaded file to edit the action in the same form?

## dynamic: activation of the update of an InputField that has {Temporary, update function}

I have a DynamicModule that contains several InputFields and a button to cause recalculation. The calculation takes a while, so I am using the dynamic formulation [varname, {temporary, updatefunction}]. But if I have the cursor in a field that I have edited, and then I click on the recalculate button, the recalculation is performed without the updated version of varname. What can I add to the button code to induce the update, regardless of the field in which the cursor is located? For example, is there a way to simulate putting a tab key in the input sequence, which would cause the cursor to leave the current field and move on to the next one?

## mysql: PHP PDO call procedure and shortly after selecting the temporary table

I have a procedure that creates a temporary table and I need to select it shortly after. I am using pdo and it always returns some error, in my last code the error 500 appears and I don't know where to go.

``````\$proc = \$this->conn->prepare("CALL proc_busca_disponivel(?)");
\$proc->bindParam(1, \$id_evento, PDO::PARAM_INT, 4000);
\$proc->execute();
\$proc->closeCursor();

\$stmt = \$this->conn->prepare("SELECT * from LISTA_DISPONIVEL");
\$stmt->execute();

\$res = \$stmt->fetchAll(PDO::FETCH_ASSOC);

var_dump(\$res);
``````

It is not me who creates the database. If I execute the queries in the mysql panel, it returns perfectly, so I conclude that I am missing the point.
I also activated and deactivated the pdo buffers, as I had indicated it in the error in other attempts to create the code, but so far I have only passed error 500.

``````\$this->conn->setAttribute(PDO::MYSQL_ATTR_USE_BUFFERED_QUERY, true); //ou false dá no mesmo
``````


text:
# Solve Predator-Prey Equations

This example shows how to solve a differential equation representing a predator/prey model using both ode23 and ode45. These functions are for the numerical solution of ordinary differential equations using variable step size Runge-Kutta integration methods. ode23 uses a simple 2nd and 3rd order pair of formulas for medium accuracy and ode45 uses a 4th and 5th order pair for higher accuracy.

Consider the pair of first-order ordinary differential equations known as the Lotka-Volterra equations, or predator-prey model:

$\begin{array}{l}\frac{\mathrm{dx}}{\mathrm{dt}}=\mathit{x}-\alpha \mathrm{xy}\\ \frac{\mathrm{dy}}{\mathrm{dt}}=-\mathit{y}+\beta \mathrm{xy}.\end{array}$

The variables $\mathit{x}$ and $\mathit{y}$ measure the sizes of the prey and predator populations, respectively. The quadratic cross term accounts for the interactions between the species. The prey population increases when no predators are present, and the predator population decreases when prey are scarce.

### Code Equations

To simulate the system, create a function that returns a column vector of state derivatives, given state and time values. The two variables $\mathit{x}$ and $\mathit{y}$ can be represented in MATLAB as the first two values in a vector y. Similarly, the derivatives are the first two values in a vector yp. The function must accept values for t and y and return the values produced by the equations in yp.

yp(1) = (1 - alpha*y(2))*y(1)

yp(2) = (-1 + beta*y(1))*y(2)

In this example, the equations are contained in a file called lotka.m. This file uses parameter values of $\alpha =0.01$ and $\beta =0.02$.

type lotka
function yp = lotka(t,y)
%LOTKA  Lotka-Volterra predator-prey model.

%   Copyright 1984-2014 The MathWorks, Inc.

yp = diag([1 - .01*y(2), -1 + .02*y(1)])*y;

### Simulate System

Use ode23 to solve the differential equation defined in lotka over the interval $0. Use an initial condition of $\mathit{x}\left(0\right)=\mathit{y}\left(0\right)=20$ so that the populations of predators and prey are equal.

t0 = 0;
tfinal = 15;
y0 = [20; 20];
[t,y] = ode23(@lotka,[t0 tfinal],y0);

### Plot Results

Plot the resulting populations against time.

plot(t,y)
title('Predator/Prey Populations Over Time')
xlabel('t')
ylabel('Population')
legend('Prey','Predators','Location','North')

Now plot the populations against each other. The resulting phase plane plot makes the cyclic relationship between the populations very clear.

plot(y(:,1),y(:,2))
title('Phase Plane Plot')
xlabel('Prey Population')
ylabel('Predator Population')

### Compare Results of Different Solvers

Solve the system a second time using ode45, instead of ode23. The ode45 solver takes longer for each step, but it also takes larger steps. Nevertheless, the output of ode45 is smooth because by default the solver uses a continuous extension formula to produce output at four equally spaced time points in the span of each step taken. (You can adjust the number of points with the 'Refine' option.) Plot both solutions for comparison.

[T,Y] = ode45(@lotka,[t0 tfinal],y0);

plot(y(:,1),y(:,2),'-',Y(:,1),Y(:,2),'-');
title('Phase Plane Plot')
legend('ode23','ode45')

The results show that solving differential equations using different numerical methods can produce slightly different answers.


text:
## High q-State Clock Spin Glasses in Three Dimensions and the Lyapunov Exponents of Chaotic Phases and Chaotic Phase Boundaries    [PDF]

Efe Ilker, A. Nihat Berker
Spin-glass phases and phase transitions for q-state clock models and their q $\rightarrow \infty$ limit the XY model, in spatial dimension d=3, are studied by a detailed renormalization-group study that is exact for the d=3 hierarchical lattice and approximate for the cubic lattice. In addition to the now well-established chaotic rescaling behavior of the spin-glass phase, each of the two types of spin-glass phase boundaries displays, under renormalization-group trajectories, their own distinctive chaotic behavior. These chaotic renormalization-group trajectories subdivide into two categories, namely as strong-coupling chaos (in the spin-glass phase and, distinctly, on the spinglass-ferromagnetic phase boundary) and as intermediate-coupling chaos (on the spinglass-paramagnetic phase boundary). We thus characterize each different phase and phase boundary exhibiting chaos by its distinct Lyapunov exponent, which we calculate. We show that, under renormalization-group, chaotic trajectories and fixed distributions are mechanistically and quantitatively equivalent. The phase diagrams of arbitrary even q-state clock spin-glass models in d=3 are calculated. These models, for all non-infinite q, have a finite-temperature spin-glass phase. Furthermore, the spin-glass phases exhibit a universal ordering behavior, independent of q. The spin-glass phases and the spinglass-paramagnetic phase boundaries exhibit universal fixed distributions, chaotic trajectories and Lyapunov exponents. In the XY model limit, our calculations indicate a zero-temperature spin-glass phase.
View original: http://arxiv.org/abs/1301.2794


text:
Duke Mathematical Journal

On unitarity of spherical representations

Jesper Bang-Jensen

Article information

Source
Duke Math. J., Volume 61, Number 1 (1990), 157-194.

Dates
First available in Project Euclid: 20 February 2004

Permanent link to this document
https://projecteuclid.org/euclid.dmj/1077296652

Digital Object Identifier
doi:10.1215/S0012-7094-90-06108-3

Mathematical Reviews number (MathSciNet)
MR1068384

Zentralblatt MATH identifier
0752.22011

Citation

Bang-Jensen, Jesper. On unitarity of spherical representations. Duke Math. J. 61 (1990), no. 1, 157--194. doi:10.1215/S0012-7094-90-06108-3. https://projecteuclid.org/euclid.dmj/1077296652

References

• [1] J. Bang-Jensen, The multiplicities of certain $K$-types spherical representations, Journal of Functional Analysis (to appear).
• [2] D. Barbasch, The unitary dual for complex classical Lie groups, Invent. Math. 96 (1989), no. 1, 103–176.
• [3] K. D. Johnson and N. R. Wallach, Composition series and intertwining operators for the spherical principal series. I, Trans. Amer. Math. Soc. 229 (1977), 137–173.
• [4] A. W. Knapp and E. M. Stein, Intertwining operators for semisimple groups. II, Invent. Math. 60 (1980), no. 1, 9–84.
• [5] B. Kostant, On the existence and irreducibility of certain series of representations, Lie groups and their representations (Proc. Summer School, Bolyai János Math. Soc., Budapest, 1971), Halsted, New York, 1975, pp. 231–329.
• [6] B. Speh and D. A. Vogan, Jr., Reducibility of generalized principal series representations, Acta Math. 145 (1980), no. 3-4, 227–299.
• [7] D. A. Vogan, Jr., Representations of real reductive Lie groups, Progress in Mathematics, vol. 15, Birkhäuser Boston, Mass., 1981.
• [8] D. A. Vogan, Jr., Unitarizability of certain series of representations, Ann. of Math. (2) 120 (1984), no. 1, 141–187.
• [9] D. A. Vogan, Jr., The unitary dual of $\rm GL(n)$ over an Archimedean field, Invent. Math. 83 (1986), no. 3, 449–505.
• [10] D. A. Vogan, Jr., Unitary representations of reductive Lie groups, Annals of Mathematics Studies, vol. 118, Princeton University Press, Princeton, NJ, 1987.
• [11] J. A. Wolf, The action of a real semisimple Lie group on a complex flag manifold. II. Unitary representations on partially holomorphic cohomology spaces, American Mathematical Society, Providence, R.I., 1974.


text:
Subjects -> TRANSPORTATION (Total: 212 journals)     - AIR TRANSPORT (9 journals)    - AUTOMOBILES (26 journals)    - RAILROADS (10 journals)    - ROADS AND TRAFFIC (9 journals)    - SHIPS AND SHIPPING (39 journals)    - TRANSPORTATION (119 journals) TRANSPORTATION (119 journals)
 Showing 1 - 53 of 53 Journals sorted alphabetically Accident Analysis & Prevention       (Followers: 117) Analytic Methods in Accident Research       (Followers: 8) Applied Mobilities       (Followers: 2) Archives of Transport       (Followers: 18) Asian Transport Studies Botswana Journal of Technology       (Followers: 1) Case Studies on Transport Policy       (Followers: 16) Cities in the 21st Century       (Followers: 15) Danish Journal of Transportation Research / Dansk Tidsskrift for Transportforskning       (Followers: 2) Decision Making : Applications in Management and Engineering       (Followers: 1) Economics of Transportation       (Followers: 14) Emission Control Science and Technology       (Followers: 2) eTransportation       (Followers: 2) EURO Journal of Transportation and Logistics       (Followers: 15) European Transport Research Review       (Followers: 24) Geosystem Engineering       (Followers: 2) IATSS Research IEEE Open Journal of Intelligent Transportation Systems       (Followers: 7) IEEE Vehicular Technology Magazine       (Followers: 7) IET Electrical Systems in Transportation       (Followers: 11) IET Intelligent Transport Systems       (Followers: 11) IFAC-PapersOnLine       (Followers: 1) International Journal of Applied Logistics       (Followers: 11) International Journal of Crashworthiness       (Followers: 12) International Journal of e-Navigation and Maritime Economy       (Followers: 5) International Journal of Electric and Hybrid Vehicles       (Followers: 11) International Journal of Electronic Transport       (Followers: 9) International Journal of Heavy Vehicle Systems       (Followers: 7) International Journal of Intelligent Transportation Systems Research       (Followers: 14) International Journal of Mobile Communications       (Followers: 9) International Journal of Ocean Systems Management       (Followers: 3) International Journal of Services Technology and Management       (Followers: 1) International Journal of Sustainable Transportation       (Followers: 18) International Journal of Traffic and Transportation Engineering       (Followers: 18) International Journal of Transportation Engineering       (Followers: 1) International Journal of Transportation Science and Technology       (Followers: 11) International Journal of Vehicle Systems Modelling and Testing       (Followers: 3) Journal of Advanced Transportation       (Followers: 16) Journal of Big Data Analytics in Transportation       (Followers: 1) Journal of Mechatronics, Electrical Power, and Vehicular Technology       (Followers: 6) Journal of Modern Transportation       (Followers: 9) Journal of Navigation       (Followers: 279) Journal of Sport & Social Issues       (Followers: 12) Journal of Sustainable Mobility       (Followers: 3) Journal of Traffic and Transportation Engineering (English Edition)       (Followers: 5) Journal of Transport & Health       (Followers: 10) Journal of Transport and Land Use       (Followers: 25) Journal of Transport and Supply Chain Management       (Followers: 16) Journal of Transport Geography       (Followers: 28) Journal of Transport History       (Followers: 12) Journal of Transportation and Logistics       (Followers: 4) Journal of Transportation Safety & Security       (Followers: 11) Journal of Transportation Security       (Followers: 3) Journal of Transportation Systems Engineering and Information Technology       (Followers: 12) Journal of Transportation Technologies       (Followers: 15) Journal of Waterway Port Coastal and Ocean Engineering       (Followers: 8) Journal on Vehicle Routing Algorithms Les Dossiers du Grihl       (Followers: 1) LOGI ? Scientific Journal on Transport and Logistics       (Followers: 1) Logistics       (Followers: 3) Logistics & Sustainable Transport       (Followers: 6) Logistique & Management Mobility in History       (Followers: 5) Modern Transportation       (Followers: 12) Nonlinear Dynamics       (Followers: 19) Open Journal of Safety Science and Technology       (Followers: 17) Open Transportation Journal Packaging, Transport, Storage & Security of Radioactive Material       (Followers: 4) Periodica Polytechnica Transportation Engineering Pervasive and Mobile Computing       (Followers: 8) Proceedings of the Institution of Mechanical Engineers Part F: Journal of Rail and Rapid Transit       (Followers: 15) Promet : Traffic &Transportation Public Transport       (Followers: 20) Recherche Transports Sécurité       (Followers: 1) Research in Transportation Business and Management       (Followers: 8) Revista Transporte y Territorio       (Followers: 1) Revue Marocaine de Management, Logistique et Transport Romanian Journal of Transport Infrastructure       (Followers: 1) SourceOCDE Transports       (Followers: 2) Sport, Education and Society       (Followers: 13) Sport, Ethics and Philosophy       (Followers: 3) Streetnotes       (Followers: 1) Synthesis Lectures on Mobile and Pervasive Computing       (Followers: 1) Tire Science and Technology       (Followers: 3) Transactions on Transport Sciences       (Followers: 6) Transport       (Followers: 17) Transport and Telecommunication       (Followers: 5) Transport in Porous Media       (Followers: 1) Transport Problems       (Followers: 5) Transport Reviews: A Transnational Transdisciplinary Journal       (Followers: 10) Transport technic and technology       (Followers: 1) Transportation       (Followers: 33) Transportation Geotechnics       (Followers: 1) Transportation in Developing Economies Transportation Infrastructure Geotechnology       (Followers: 8) Transportation Journal       (Followers: 16) Transportation Letters : The International Journal of Transportation Research       (Followers: 6) Transportation Research Interdisciplinary Perspectives       (Followers: 3) Transportation Research Part A: Policy and Practice       (Followers: 41) Transportation Research Part B: Methodological       (Followers: 39) Transportation Research Part C: Emerging Technologies       (Followers: 31) Transportation Research Procedia       (Followers: 7) Transportation Research Record : Journal of the Transportation Research Board       (Followers: 36) Transportation Safety and Environment       (Followers: 2) Transportation Science       (Followers: 25) Transportation Systems and Technology TRANSPORTES       (Followers: 6) Transportmetrica A : Transport Science       (Followers: 8) Transportmetrica B : Transport Dynamics       (Followers: 1) Transportrecht       (Followers: 1) Travel Behaviour and Society       (Followers: 11) Travel Medicine and Infectious Disease       (Followers: 4) Urban Development Issues       (Followers: 3) Urban, Planning and Transport Research       (Followers: 32) Vehicles Vehicular Communications       (Followers: 4) World Electric Vehicle Journal World Review of Intermodal Transportation Research       (Followers: 6) Транспортні системи та технології перевезень

Similar Journals
 Journal on Vehicle Routing AlgorithmsNumber of Followers: 0      Hybrid journal (It can contain Open Access articles) ISSN (Print) 2367-3591 - ISSN (Online) 2367-3605 Published by Springer-Verlag  [2626 journals]
• Solving a real-life roll-on–roll-off waste collection problem with
column generation
• Abstract: Abstract In this paper, we develop an intelligent solution to a complex, real-life vehicle routing problem in the waste management sector. Waste management companies deliver various types of empty waste containers to industrial customers, to be filled with different types of waste, after which the containers are picked up again. The full containers are transported to a so-called waste management depot or waste handling depot, where they are emptied, after which they are reused. Empty containers are stocked in various stock depots. Time windows in which containers may be picked up and delivered at the customers and opening hours of the different depots have to be taken into account additionally. Very importantly, there are two types of waste collection trucks that can, respectively, carry one or two containers. The resulting vehicle routing problem belongs to a class of so-called roll-on–roll-off problems, characterized by unit demand. Additionally, the problem discussed in this paper has several characteristics (multiple waste types, multiple container types, multiple depots, a heterogeneous fleet, pickup and delivery, time window constraints, and other) that make solving it a difficult task. To solve this problem, we develop a novel column generation scheme that incorporates a heuristic approach to generate new columns. The master problem is solved by linear relaxation of a set partitioning problem. New routes (columns) are generated by a constructive heuristic loosely based on Solomon’s insertion heuristic for the vehicle routing problem with time windows. The construction heuristic operates on a reformulated version of the roll-on–roll-off problem, i.e., a generalized vehicle routing problem with time windows. The algorithm—called wmpopt—is submitted to an extensive sensitivity analysis to determine its response to different parameter settings. After this, we test it on four real-life problem instances and compare its results to those obtained by a commercial solver. We show that wmpopt achieves much better solutions than the commercial solver in similar computing times.
PubDate: 2019-05-10

• Emergent intelligence technique-based transport depot resource management
in a metropolitan area
• Abstract: Abstract A metropolitan area experiences transport resource scarcities and dynamic resource allocation problems due to huge number of commuters’ population, dynamic commuters’ arrival rates, etc. The progress of these problems results into economic loss, traffic congestion, inefficient utilization of resources and increase in indefinite waiting time of commuters. Hence, we propose a dynamic transport resource allocation scheme. The scheme efficiently manages number of vehicles over time and space using emergent intelligence (EI) technique. Based on the historical information, commuters’ arrival rates, resource availability, deficit resources, surplus resources of neighbor depots, etc., the EI technique with agents is used for collecting, analyzing, sharing and allocating resources, for optimal utilization of resources in a metropolitan area. Analytical model of EI technique-based transport resource allocation scheme is developed using Markov chain, and derived the closed-form expression of optimal utilization of resources. Performance evaluation is carried out with varying number of commuters’ arrival rates, vehicles, requests and number of neighborhood depots. We observe that results obtained in the simulation and analysis reflect the effectiveness of the proposed scheme in a metropolitan area.
PubDate: 2019-03-18

• The VeRoLog Solver Challenge 2019
• Abstract: Abstract The VeRoLog Solver Challenge 2019 is the $${4{\mathrm{th}}}$$ solver challenge facilitated by VeRoLog, the EURO Working Group on Vehicle Routing and Logistics. The challenge is organized in cooperation with ORTEC. On behalf of the organizing committee, the authors report on the problem and organization of the challenge.
PubDate: 2019-03-13

• On automatic algorithm configuration of vehicle routing problem solvers
• Abstract: Abstract Many of the algorithms for solving vehicle routing problems expose parameters that strongly influence the quality of obtained solutions and the performance of the algorithm. Finding good values for these parameters is a tedious task that requires experimentation and experience. Therefore, methods that automate the process of algorithm configuration have received growing attention. In this paper, we present a comprehensive study to critically evaluate and compare the capabilities and suitability of seven state-of-the-art methods in configuring vehicle routing metaheuristics. The configuration target is the solution quality of eight metaheuristics solving two vehicle routing problem variants. We show that the automatic algorithm configuration methods find good parameters for the vehicle route optimization metaheuristics and clearly improve the solutions obtained over default parameters. Our comparison shows that despite some observable differences in configured performance there is no single configuration method that always outperforms the others. However, largest gains in performance can be made by carefully selecting the right configurator. The findings of this paper may give insights on how to effectively choose and extend automatic parameter configuration methods and how to use them to improve vehicle routing solver performance.
PubDate: 2019-02-22

• A look-ahead partial routing framework for the stochastic and dynamic
vehicle routing problem
• Abstract: Abstract In this paper, we study the vehicle routing problem with dynamic customers, where a portion of the customer requests are known in advance and the rest arrive in real time. We propose an optimization-based look-ahead dynamic routing framework that involves request forecasting, partial planning, and dynamic real-time routing of the fleet. This framework has the capabilities for adjustments in response to routing environments with different levels of uncertainties. Through extensive numeral simulations, we exam its performance in routing environments with various levels of uncertainties. We demonstrate the efficiency and robustness of the proposed solution by benchmarking against two other routing strategies. This paper fills the gap in the literature on studying the relationship between the level of route planning in the solution approach and the quality of the solution under various system conditions.
PubDate: 2018-11-01

• Performance analysis of a metaheuristic algorithm for the line-haul feeder
vehicle routing problem
• Abstract: Abstract The line-haul feeder vehicle routing problem (LFVRP) is a rather new and therefore hardly investigated problem and can be seen as vehicle routing problem with synchronisation constraints. Synchronisation takes place if two or more vehicles (small and large vehicles) meet at the same place and at the same time and perform a transshipment of goods. Small vehicles are used to serve customers which are difficult to access (e.g. due to traffic jams, narrow streets or limited parking space). The downside is their limited capacity. To avoid the journey back to the depot, the small vehicle can meet with a large vehicle at a customer with enough space for reloading. Thus, the small vehicle uses the large vehicle as virtual depot and is able to save time and reduce costs. In Brandstätter and Reimann (Eur J Oper Res 270:157–170, 2018), we already introduced two promising solution approaches to master the LFVRP—the Linkage- and Split-Approach. Both approaches were shown to find high-quality solutions in short time. Moreover, we demonstrated the advantage of the LFVRP strategy when compared with the heterogeneous fleet vehicle routing problem. With this paper, we propose and justify several improvements to our original algorithms. These include the application of Ant Colony Optimization, different local search operators, as well as the exact solution of a sub-problem. To highlight the performance contribution of these modifications, we perform a thorough and extensive computational experiment. We evaluate each algorithmic component individually as well as their combination and statistically validate the benefits. Overall, we find that the final algorithm improves our previous approaches by almost 9% at a computational cost of a few seconds.
PubDate: 2018-11-01

• Intelligent motion planning of a mobile robot with dynamic obstacle
avoidance
• Abstract: Abstract Intelligent navigation in cluttered environment while insuring maximum safety and task efficiency is a challenging subject. Motion planning is an important issue in the field of autonomous mobile robots which makes them capable to travel from one position to another in various environments including both static and dynamic obstacles without any human intervention. This research is conducted for the purpose of designing and programming a mobile robot using two separated fuzzy logic controllers to develop an intelligent algorithm in order to avoid both static and dynamic obstacles. These fuzzy logic controllers play a significant role in mobile robot navigation and obstacle avoidance behavior. In this work, four essential behavior controllers are designed and implemented onto the robot to assist its navigation towards the goal which are: goal reaching behavior, speed control behavior, goal searching behavior and obstacle avoidance behavior. The obstacle avoidance behavior is divided into two individual behaviors which are static obstacle avoidance behavior and dynamic obstacle avoidance behavior where these behaviors are controlled by an artificial intelligence (AI) algorithm. In order to design obstacle avoidance behavior, Sugeno fuzzy logic was applied. The simulation of this research was done by MATLAB software where a mobile robot and some experimental environments with different complexity were created. Several navigation tests were conducted and the robot’s behavior were observed as well. Analysis of the robot’s performance validated the effectiveness of the proposed controllers and the robot could successfully navigate to reach the goal through all experimental environments.
PubDate: 2018-11-01

• Heuristics for the weighted k -rural postman problem with applications to
urban snow removal
• Abstract: Abstract We describe a weighted version of the k-Chinese and k-rural postman problem that occurs in the context of snow removal. The problem concerns the questions of which vehicle shall take care of each link and how the vehicles shall travel between links. We also consider different numbers of vehicles, in view of a fixed cost for each vehicle. We describe and discuss heuristic solution approaches, based on usable substructures, such as heuristics for rural postman problems, meta-heuristics, k-means clustering and local search improvements by moving cycles. The methods have been implemented and tested on real life examples.
PubDate: 2018-11-01

• The VeRoLog solver challenge 2016–2017
• Abstract: Abstract The VeRoLog Solver Challenge 2016–2017 is the third solver challenge facilitated by VeRoLog, the EURO Working Group on Vehicle Routing and Logistics Optimization, and is organized in cooperation with ORTEC B.V. The authors constitute the organizing committee of this challenge, and with this paper they report on the problem and organization of this challenge.
PubDate: 2018-03-01

• Commuters’ traffic pattern and prediction analysis in a metropolitan
area
• Abstract: Abstract A metropolitan area is an area with dynamic demands and is one of the main indicators of economic growth of nation. It involves the complexity of efficient analysis and prediction of patterns of growth or decline of traffic volume and patterns of resource utilization with respect to time and place. To solve these complexities, we propose agent-based commuters’ traffic pattern and prediction analysis model in a metropolitan area. The proposed system model is capable of analyzing and predicting the patterns of commuters’ traffic flow volume and resource utilization in each zone and region, using the population density, availability of resources, type of place, time period, and commuters’ and vehicles’ arrival rates. The proposed model provides qualitative form of traffic; increases the probability of measure of unpredictable information; and aids in emergency traffic planning and route-finding services. The result shows the effectiveness of the model at different time periods in a day for forecasting of the resource utilization and changes in traffic volumes in zones and regions in the metropolitan area.
PubDate: 2018-03-01

• Vehicle routing problems with deliveries split over days
• Abstract: Abstract In the classical (Capacitated) Vehicle Routing Problem (CVRP) we seek to use a fleet of trucks to deliver goods to customers at minimal cost, and customers’ requests must be fulfilled in a single visit. In the Split Delivery Vehicle Routing Problem (SDVRP), we are allowed to visit a customer multiple times to fulfil their demand. In this paper, we study a variant of SDVRP where customers have to be served over a multi-period horizon, and each customer may require service on one or more days. We consider the possibility of splitting a request not only between vehicles on the same day but also across consecutive days. The objective is to find a set of routes for each day of the planning horizon so that the total travelling cost is minimised, and the total amount delivered meets customers’ demand. We show that this Multi-Day version of SDVRP is structurally different to the usual SDVRP. We also consider a Fleet Size and Mix variant of the problem, where a fixed cost for using a vehicle at all during the horizon is added to the objective function. We propose a Mixed Integer Linear Programming approach to solve the Multi-Day SDVRP, together with some valid inequalities to enhance it. Furthermore, we develop a large neighbourhood search-based heuristic which provides upper bounds for the proposed mathematical formulation, which proves effective in reducing solution times. We present a theoretical study of the problem, extending some known properties of the VRP with split deliveries, and an extensive computational analysis aimed at studying the strengths and weakness of the proposed strategy.
PubDate: 2018-03-01

• Load transfer operations for a dynamic vehicle routing problem with mixed
backhauls
• Abstract: Abstract We consider a dynamic vehicle routing problem with mixed backhauls (DVRPMB) that seeks to plan, in the most efficient way, the delivery of dynamic pickup orders that arrive in real time, while a predefined plan of serving static delivery orders is being executed. Maintaining the original assignment of delivery orders to vehicles may limit system performance, since the changes in the system state caused by the arriving dynamic orders may grant re-assignments of such orders advantageous. Thus, in this paper, we introduce and solve a variant of DVRPMB that allows orders to be transferred between vehicles during plan implementation. We refer to this problem as the DVRPMB with load transfers (DVRPMB-LT). Since the problem is solved with periodic re-optimization, we focus on the underlying optimization problem, develop an appropriate model using an arc-based formulation, and compare the exact solutions to the ones of the corresponding problem that does not allow transfers. Furthermore, we develop a practical heuristic framework to address the complexity of DVRPMB-LT and solve cases of practical relevance. Subsequently, we employ the proposed framework to solve and analyze the full dynamic problem.
PubDate: 2018-03-01

• Heuristic evaluation of the characteristic function in the Cooperative
Inventory Routing Game
• Abstract: Abstract This paper is concerned with the problem of the characteristic function evaluation for the game theory model of horizontal cooperation of carriers on large transportation networks. We consider a mathematical formalization of the Cooperative Inventory Routing Game (CIRG) in the form of characteristic function. Due to non-exact evaluation of the minimal cost for the coalitions, we have the subadditivity property of the characteristic function to be not fulfilled in general case. To calculate the values of characteristic function that satisfy the subadditivity condition, the Direct Coalition Induction Algorithm (DCIA) is used. To solve the multi-depot Inventory Routing Problem for each coalition, the Dynamic Adaptation procedure for Large Neighborhood Search (ALNS) is applied. Calculation of the characteristic function vales, DCIA performance, and advantages of Dynamic Adaptation for ALNS are demonstrated with computational experiments. It is shown that an experimental level of time consistency of the solutions generated by DALNS for given IRP benchmark instances appears to be higher in average in comparison with the solutions generated by ALNS.
PubDate: 2018-03-01

JournalTOCs
School of Mathematical and Computer Sciences
Heriot-Watt University
Edinburgh, EH14 4AS, UK
Email: journaltocs@hw.ac.uk
Tel: +00 44 (0)131 4513762


text:
# Countable intersection of almost sure events is also almost sure

Suppose that $\{B_n\}_{n\in\mathbb N}$ are almost sure events, i.e. $\mathbb P(B_n)=1, \forall n$. Then how do I show that their intersection is also a sure event, i.e. $\mathbb P\left(\cap_{n=1}^\infty B_n\right)=1$. Thanks!

Let's consider complements $B_n^c$ to $B_n$. For any $n$ it holds that $\mathbb{P}(B_n^c) = 0$.
Using countable additivity for measures we get: $$\mathbb{P} \left(\bigcap_{n = 1}^{\infty} B_n \right) = 1 - \mathbb{P}\left(\bigcup_{n = 1}^{\infty} B_n^c \right) \geq 1 - \sum_{n = 1}^{\infty} \mathbb{P}(B_n^c) = 1.$$ So $$1 \geq \mathbb{P}(\cap_{n = 1}^{\infty} B_n) \geq 1.$$ Consequently $$\mathbb{P}(\cap_{n = 1}^{\infty} B_n) = 1.$$