text:
# QA’s Q&A – Gỡ rối tâm tình

Hi,

I was introduced to your blog just this morning (May 12). While browsing I happened to read your post about Political Economy and I think this is what I want to pursue in college (I am a freshman of Class of 2018).

But I need to know better before I make any important decision, so could you explain what exactly Political Economy is, and how it is different from Liberal Economy and the “economy” that is being taught in college (and if possible, differences between these two sub-fields).

Concerning my major, I am oscillating between Economics and Political Science. That is partly because of career-related interests (what job to take if I took Pol Sci – according to my mother), and partly because I’m still uncertain which field suits me better. In some way, I seem interested in political issues but only those that directly affect economical well-being of the country’s population, like (for Vietnam) interest groups and what communism/capitalism has to do with anything, but not much in diplomatic issues like the war in Middle East or public policies like Obamacare.

– Vy

#### Prologue

Thanks to this reader’s question, it’s time for a very belated addendum to our Why Political Economics? series (here and here). Four years have gone by since the last instalment — and gone, too, are a lot of ideals and misunderstandings that I held as a second-year-in-college. So, here is a less wrong answer to Why Political Economics? from a second-year-in-PhD-studies.

#### I. The three types of Political Economy

Given its broad and deep lineage, the only appropriate definition of Political Economy is perhaps the study of how politics and economic decision-making intertwine. There have been three main traditions in the field.

First is mercantilism, which espouses the idea that statesmen should use economic policy to enhance their nations’ power. Mercantilism thrived in 16th-18th Europe, when the international system was thoroughly anarchic and populated with equally powerful countries. No one is ever sure about anyone else (Game of Thrones style), leading to frequent wars and ultimately the idea that economic policy is subservient to the survival of the states. While this mode of thinking has gone out of vogue a long time ago, we still see its remnants today in nationalist discourse under name of “protectionism.”

Second is the liberal economics  that dominates economic thinking today. Its famous origin traces back to Adam Smith’s Wealth of Nations, which was a direct response to the prevailing mercantilist thoughts of his time. While common sensical today, Adam Smith was a radical to propose that free trade benefits all countries (thanks to comparative advantage), and that free market benefits everyone (thanks to free price being an effective way to transmit information about what’s needed and available in the economy). These ideas are still the bedrock of modern economics, yet at the same time the practices of today’s economists are nothing like Adam Smith. (We’ll revisit below).

Third is Marxist economics, which is in turn a critique of the capitalist economy that has been ushered in since Adam Smith’s ideas. Marx critiqued numerous aspects of a capitalist economy. One is the paradoxical crisis of production, when there are enough goods for everyone yet the workers are too destitute to buy them. Another is the alienation of labor,  when individual man is but an inconsequential cog in the production line and thus unable to derive creative satisfaction from labor. Contrary to the mercantilist, for Marx, politics is subservient to economic powers: the ruling economic class promotes certain kinds of political and religious ideology in order to prolong its hegemony.

On the ruin of the Soviet Union, liberal economics raised its triumphant flag and became synonymous with Economics. Yet political economy as studied and practiced today is very unlike Adam Smith’s, and we will see how.

#### II. The ONE type of Political Economy (if you ask U.S. academics)

Over the 20th century economics has evolved several times in order to grapple with the gap between economic theory and reality.

Once staunch believers in free market, economists started to notice numerous market failures from causes such as natural monopoly (i.e. due to economy of scale) and informational asymmetry (i.e. sellers may have private information about the good that buyers don’t, in which case they can’t agree on a price). The existence of market failure seems to argue for government intervention. For example, the government may put in place anti-trust law or product quality regulations.

But yet again, economists noticed that governments fail, too. We view men as self-interested, maximizing actors in the economic realm — there is no reason why they would be altruistic and benevolent in the political arena. This is in fact and old idea, and as James Madison put it: “If men were angels, no government would be necessary. If angels were to govern men, neither external nor internal controls on government would be necessary.” Thus, a new area of study sprung up to take the economic assumptions (rational, self-maximizing agent) and methods (dominantly game theory) to investigate political behaviors. It is called Public Choice, and is what Political Economy means today.

#### III. So, should you study Political Economy / Political Science?

After learning a lot more about Political Economy, I am fortunate enough not to find out that I was wrong 4 years ago. I stood by the claim that, yes, it is foolish to study economic development (or any economic policy-making) without considering politics. The most that economics can give us is a description of various trade-offs, whereas which side of those trade-offs do nations end up choosing is fundamentally a political question.

Having said that, I do feel disappointed with my study of Political Economy, mainly because I came to it with very high expectation (you could see the exuding optimism in the previous instalments in the series.) I thought that if only I could get a PhD in Political Economy I would be able to finally know what countries like Vietnam would need to develop, what I could do to “change lives” and “make the world a better place.”

But development is hard. Many smart people have worked on it for years without a solution. And yet that’s not even the discouraging part. What’s more disheartening about social science is that we are not sure if we are getting any closer to the solution at all. That is because:

• Without the ability to do experiment (i.e. to re-run history) in order to hold all other factors constant, it is nigh-impossible to decisively conclude what factor is causing what.
• Yes, there is a surge in Randomized Control Trials in development economics but 1) due to real-world limitations there are certain things we cannot randomize (e.g. political system), and 2) a successful program may fail when scaled-up (basically political actors interfered when the program became a big pot of money).
• Social sciences study humans, and unlike atoms humans have intentions and wills that change. When something is proven in physics, it stays proven. There is no such law in economics and political science.

Of course, despite all these dead-ends the development industry continues to chug along anyway with a new way to change lives every few years. Like fashion, these development ideas come and go in circle with no clear sense of progress. Not only have we been ineffective, some would argue that developmental aid is downright harmful in some cases.

All in all, I think that Political Economy embodies the fundamentally correct insight that we need politics to understand development. However, let us not be mistaken (as I was) that we are anywhere close to achieving that understanding yet.

#### IV. So, should you major in Economics / Political Science?

Fascinatingly, even if you want to study Political Economy, it is not clear that you should major in Economics or Political Science.

It is important that you think about jobs. My college career was colored by my disdain for material things and my fascination with intellectual pursuit (as you can see from my old, college-era blog entries.) Looking back, I have to admit that I got the balance slightly wrong. Sure, big ideas are exhilarating, but I am not sure any amount of that can offset the months of stress unemployment will bring. (I applied for graduate school and was spared the entire ordeal, but I have seen way too many struggles.) Since most people would advise you to “try new things” and “expand your horizon,” I hope to bring back some perspective and urge you to think about where you want to be after 4 years of college. (Listen to this NPR broadcast about the economic return of different majors.)

The best way to prepare for that moment in 4 years is to learn skills, not facts. In this day and age, when everything can be looked up there is very little value in knowing a lot of facts about an area. In contrast, to learn technical skills you have to study sequentially (e.g. you need arithmetic before algebra before calculus), and the only time to do that well is in school.

(Note that even though I will be mainly talking about how to best prepare yourself as a worker, that is not the only goal of education. Minor in something that best prepare you as a human being and a citizen. In terms of social sciences / humanities, (for me) that means taking Intro to Econs, Microeconomics, Macroeconomics, a class on comparative political system, moral philosophy, and arts.)

Back to the main topic: depending on what job you want to get, below are your options.

First, if you want to get a private-sector job, a BA in political science is sort of worthless, and a BA in economics is only slightly less so (unless you go to a top research school OR work on frontier research with professors). The reason is that undergraduate political science training is heavily about facts and teach you little employable skills. Economics BA is slightly better since you will get to learn econometrics, but everything else you have to learn (e.g. microeconomic and macroeconomic theories) is of little value on the job market.

Having said that, employers do hire more Economics major, but not for the economic knowledge. Instead, the Econs label is simple a signal of quantitative skills. I thus recommend you to go straight to the quantitative skills (e.g. Econometrics, Statistics) and bypass all the economic theories that you will never use.

Second, if you want to work in the development sector, understand that it is a crowded field with low pay that typically requires post-graduate degrees. It is crowded with low pay for a reason, of course: many people are more than happy to make that sacrifice in order to do meaningful work. The best way to prepare is still to major in something quantitative (i.e. Statistics, Economics), but also take more of other electives, e.g. Political Science / Economics of Development / History, and get some development-related internships.

Third, even if you want to pursue a PhD in Political Economy, you should not major in BA Political Science. Not only are the readings in BA Political Science very outdated, the BA also does not prepare you for the increasingly quantitative and formal methods in PhD Political Science. So major in Statistics, maybe Computer Science, take multiple electives in Micro / Macroeconomics, study the area of Poli Sci that you are interested in,* and take some History classes for a reality check against the theoretical models in Econs and Poli Sci. Write a research paper in one of these electives in order to prove your interest in Political Economy and get good letters of recommendations. (You can read my entry on how to apply to PhD here.)

(* Political Science has 4 sub-fields: comparative politics (comparing systems across countries), American politics, International Relations, and Political Theory (i.e. political philosophy). If you are only interested in development, i.e. comparative politics, then it’s another reason not to major in Poli Sci so that you can bypass all the other stuffs.)

That was a lot to cover. These are the things I wish I had known four years ago, but no one was around to tell me. More troublesome is the fact that I still don’t see anyone telling college freshmen straight-talk about their career like this. Being straight talk, each paragraph of this entry can be controversial and should be more thoroughly argued in a blog post of its own. If there is any advice that does not seem clear of reasonable, I’d be happy to clarify.

Advertisements

Chào anh giai,

We all know that applying to graduate school is not gonna be like college application. Neither is (I presume) choosing an “ideal” grad school/program for your next 5-or-more years. But how so? What should be the major criteria for grad school selection, now that the usual benchmarks to judge an undergraduate institution (e.g. study abroad, diversity, campus atmosphere…) might not matter nearly as much?

Đa tạ anh giai,

– ZerO

The difference between undergraduate and graduate school is that the latter is unequivocally about getting a job. Following one’s dream–the other, oft-mentioned reason for getting a PhD–is not good enough. Five years of graduate school costs half a million dollars (\$50,000 tuition + \$50,000 lost earning per year). You could deposit that money into the bank and pursue whatever topic that strikes your intellectual fancy.

If getting a PhD is all about training for a job, then you should know about that job market. I highly recommend all PhD applicants to read the following post by a tenured associate professor about the career prospective in Political Science. The take home message is this: there are very few employment opportunities for PhDs that come from outside of top-25 departments. So, only apply to top-25 departments. The post is truthful and informative, if brutally so. I have nothing more to add besides my personal affirmation. Even in my top-10 department, frequent jokes about unemployment are no doubt rooted in a certain degree of self-consciousness.

If one squints his optimistic eye hard enough, he can see a bright side to all this: with only 25 schools to choose from, a typical student that applies to 7-8 schools doesn’t have to digest too much information. Narrowing from 25 to 8 is a matter of finding a fit, as follows, in order of decreasing importance. (Side note for other readers: in top-25, even 50, PhD programs, it is safe to assume that tuition will be waived and stipend provided. So funding is not a significant factor in choosing where to apply.)

Methodological fit: qualitative versus quantitative.
Sub-field fit: IR / American / Comparative / Political Theory.
Regional fit.
Topical fit: specific research topics such as authoritarianism, elections, parties, etc.

What is perhaps less obvious and more helpful than the above list is how to find out about whether you fit into a department. The best way is to look up the departments of authors that inspire your research. Since materials that you learn in undergraduate political science are often classics, a caveat is that those scholars may have moved on to other things. Make sure to look up their current projects. Better yet, find the up-and-coming scholars in latest journal articles that work on your topics.

There are two difficulties with this approach: 1) scholars may not publicly post their current work, and 2) among numerous articles, you’re not sure which one is really a scholar’s pet topic. Consult the professors that know your field on these matters. And don’t ask the tenured professors. Having been out of the job market for a long time, they may be eager to help but not much helpful. Seek guidance from young assistant professors and TAs, whose experience are still raw and advice relevant.

Having said all this about fit, I must also add that at the tip-top departments, where there are numerous faculties of all methodological and substantive stripes, perhaps fit does not matter very much. Anyone would fit there, so they are only keen on finding the “brightest,” whatever that means.

Finally, spread your application list a bit across dream, reach, and safety schools. Ask the aforementioned assistant professors and TAs what your reach school is. They know both you and the state of competition, thus able to give accurate estimates. Plus, by asking them to assess your chances, you get a glimpse into how enthusiastic their recommendation letters will be.

Introduction

I recently noticed how bizarre it is that I have stopped writing much, leaving this blog to languish and despair, despite the fact that writing is the single most important skill to my current career as a graduate student. Too shamed by my own long-held belief of writing as a craft, and hence can and should be practiced into perfection, I am skipping my weekly gaming session, administering a reddit diet, and writing this very line before your eyes.

So, here we go, QA’s Q&A \#5 (you can read more about this series here)

How this Q&A works

As someone who has just finished his own graduate school application last year, I can assure you that the Internet has all the answers. What it is not so good at doing, and which this blog will accomplish, is to tell you what questions to ask. As you upperclassmen already knew, time is a scarce resource — so focus on the important things.

The first version of this entry will address questions I’ve been asked by friends. Should you have any other, please leave a comment and I will add the answer to the entry.

Note: What’s written here is most true for Social Sciences in the United States. I am currently (will be for a while) a graduate student in Political Science at Duke University.

1. The big picture

Here are the factors of an application, in order of relative importance:

1. Letters of Recommendation (LoR)
2. Statement of Purpose (SoP)
3. Research Experience
4. GRE Score

What this kind of list obscures is that the first three factors – Letters, Statement, and Research – are closely related, and thus similarly valued. (GRE score is only a distant runner-up.)

Thus, one should not prepare the letters, then prepare the SoP, while juggling his research paper as if they were all separate things. All three have a mutual genesis, as explained below.

The best way to become a grad student is to act like one

Insert anything in life in place of “grad student” and this principle still holds true. The admission committee is most interested in knowing whether you will do well as a grad student. To make life even simpler, there is only one thing that they do: research.

Hence, to assure them of your potential, simply do one thing very well: research.

LoR will be a natural result of your research experience. Frequent interaction with professors during research projects is the best and most genuine way to let them know of your intellectual capacity and work ethics. There is really no trick nor shortcut to a good letter.

Similarly, your SoP will most likely grow from your research. Despite its name, a SoP is not a declaration of what you will actually do. Rather, it is to show that you understand the field, that you know what doing research actually means, and that you are able to conceive of and present scholarly ideas. Once again, doing research is the best way to learn (and to show that you’ve learned) all these things.

Because of this interconnectedness, preparing for graduate school application is a very holistic process. Start as early as possible (but ${3^{rd}}$year is not too late), approach professors whose class or research intrigue you, ask to participate in a project or to formulate your own. Very naturally, while doing research you will become familiar with certain topics, identify flaws in existing literature, come up with ideas of your own, which will serve as your future SoP material. In the mean time, you will also learn how to handle large amount of writing and, doing all this very well, earning the good graces (and good letters) of your professors.

Keep doing this until your senior year (with a brief intermission for focused GRE preparation), and by the time you actually need to ask for LoR and to write SoP, it will simply be hitting the switch of a well-oiled, multi-part machine that you have been putting together for years.

2. Letter of Recommendation

Quick answers to some FAQs on LoR.

• {How many letters?}Most schools ask for three academic letters. Some will accept the third one from outside the university. Consequently, have in mind three professors and try to write research paper with them (in or out of class). Discuss ideas with them frequently and drop hints at your plan for graduate school (all this will come up naturally, if not inevitably, during your research.)

Invest in the relationship. Having a backup ${4^{th}}$ is reasonable, but do not spread more than that. You will barely have time and energy to research with three professors anyway.

• {Who should I ask?}As in more general cases, the ones that know you best. Here in particular, that means the ones you have done research with. Ones whose class you aced is an okay substitute, but if the class is merely of the lecture/midterm/final format, the professor will not be able to comment on your research ability.

Good class taker ${\neq}$ Good researcher

… and adcom cares only about the latter

• {How early should I ask?}As referred to above, let them know of your plan some time in your junior year while working together. Then by senior’s fall, it would no longer be a surprise to everyone and need no explanation.

3. Statement of Purpose

Consult the Internet. Feel free to ask questions if you have any.

4. GRE

How important is it?

To your ability to succeed in graduate school – absolutely none. To your chance to get admitted into graduate school – somewhat.

During my post-admittance visits, I have been told by adcoms that GRE is mostly used to weed out the egregious cases and to provide some gauge for international students. Therefore, anything above 650 (old score) is good enough, and 800 makes little difference over 700.

How to study

It is not any different to any other test in the world – the best way to prepare for one is to have a lot of practice with it.

There is a very useful mental approach while laboring through GRE, however. Remember this obvious thing: your goal is to get the highest score, period. Less obvious is that this means you should not waste time criticizing (or feeling critical) about the logic of the answers or the triviality of the test. None of that helps realizing your only goal: get the highest score, period. Your job is not to defend logic, but to internalize their logic.

Reserve that truth-craving for your research instead.

(work in progress…)

Hi em,
The other day, I am thinking about this old, familiar topic: Money and Happiness. Naturally, the very common question arises: Can money buy happiness?
I look forward to hearing from you. Thanks em.

– Huy

Dear anh Huy,

I am indeed honored by your decision to direct this question to me, a 19-year-old that thinks too much for his own good, and whose only experience with hard-earned money comes from his one-semester stint as a waiter in the university restaurant. (He has picked up various jobs ever since, from tutor, IT, to research assistant – jobs that line his pocket more but develop his character less.)

I am none but a person in the making, a puzzle in the solving, and a life in the living. Really, what do I have to say about happiness?

Do not trust me. Take every word of mine with relentless skepticism, because what is at stake is your happiness, your primary pursuit in life– don’t you let anyone meddle with it.

But enough with the caveats. I must be careful not to be so good with my admonitions that you will leave this instant. Without further ado, here is QA’s Q&A #4: Can Money buy Happiness?

______________________________________________

For most people, the answer would seem to be yes.

The argument often comes in two veins. The first is proof by contradiction: If you did not have money for basic subsistence and amenities, you could not be happy. The second invokes the liberating effect of money: more cash means more control over your life. Compelling, isn’t it?

Yet equally compelling is the sudden pangs of anxiety that we suffer everyday. When we are upset, we long for happy days. When we are happy, we fear that it will not last. Telling ourselves repeatedly to not be so sad wouldn’t help. Chiding ourselves  for being  so dark wouldn’t lighten things up. These emotional crises would eventually disappear, as inexplicably as they emerged, but they would lurk behind every corner of our lives, ready to assault us in moments of vulnerability. We are completely at their mercy.

How do we make sense of this mess? Don’t I make twice the money I used to? Am I not promoted to the position I strove for? Maybe it’s not enough– yet. Maybe if only I could make a little more money, if only I could have a little nicer car, if only I could have a little bigger house. Then I would be happy.

And so people launch their lives in full force in pursuit of these “if only”. I have done that myself– so many times. In 8th grade, I thought that if only I could win the Chemistry Competition my life would be perfect. In 9th grade, I thought that if only I could get into Ams my life would be perfect (“thiên đường giải trí” was how us aspirant Amsers dubbed life after the entrance test). In high school, I thought that if only I could score 2000 SAT and get into a top 100 school, my life would be perfect.

I managed to fulfill every single one, and even more than that. Is my life perfect? Oh no. No one’s is. No one feels that his life is perfect. We always got some other “if only” to chase behind.

The problem with money is that it is nothing but another “if only”, another external thing in which (we keep hoping) lies true happiness, true happiness that is filled with content and barred from anxiety. After repeated failure with money and material goods, we may search for happiness in something subtler, like a meaningful job, or a perfect girlfriend. It is harder to dismiss these things. An increase in salary can be easily seen; thus its failure to make you happy is too blunt to equivocate. But a soul mate– how do you measure that? If a girl ends up disappointing you, it’s so much easier to label her as false positive and to shove her away in your dusty shelf of thought-to-be-true-loves. Thus most people keep leading their lives at this stage: disappointed with money, searching for some meaning of life, but never find anything that lasts.

Of course they cannot find anything that lasts, for there is nothing to be found. All of these things – from the crude (bonus, car, vacation) to the subtle (friends, lover, security) – they are all external to us. They are things in life, life that is essentially impermanent, life that has so little certainty. And yet we keep resisting this inexorable truth, and yet we keep running against the flow of inevitability, searching for more control even though it can’t be complete, clinging to ideals even though all else will fade away. We suffer because of this doggedness against life, only to be in favor of the self.

So no, I don’t think money can buy happiness. Neither can any other goals and desires, no matter how noble they may seem. Anxiety, our arch enemy, will keep stalking every step as long as we believe that there is happiness to be found in external and perishable things. Most people, after 50 years or so of living, realize that there is something wrong with such approach: the phenomenon is called the mid-life crisis (“Oh my God I only have half of my life left. What have I been doing with the first!?”). We can recreate the imminence of death faced by these people by seriously asking, “What if I died tomorrow?” Is there anything, anyone outside you that can make you feel OK about being done, gone, forgotten?

Well, you may wince and protest that this is such a dark outlook on life. Why think like this? But asking this question is like telling a depressed person: “Why be sad? Why can’t you be happy like I am?” It’s not solving the problem. Yet it is also crucial to realize that not everyone has the problem. Not everyone leaves his home to wander in the streets after learning that he got into Ams, perplexedly asking “Is this all there is?” Not everyone feels so down and void after watching a comedy and having a genuinely good laugh, heavily sighing “What now?”

Not everyone needs a solution. Many can be OK with going after one goal after another without much questioning.* If you are truly happy about whatever you are doing, be it getting rich or winning girls, just keep on doing it.

But then why do you ask this question in the first place?

___________________________________________

* I once wish if only I could be like them- carefree and not so skeptical, my life would be perfect. We know how that one works out.

If we want to change ourselves we’ll have to first accept it as it is, for change out of love is improvement. Out of hate it is destruction.

A spin-off from the original question: Should girls not attempt a Ph.D. so that she can have a better chance getting married?

Now, after this exhaustive (and exhausting) discussion of the original question, I must caution myself with the wise words of Johnathan Alter: “Logic can convince, but only emotions can motivate”, which is infinitely truer if females are involved.

I do not have any statistics to convince you Ph.D.-aspiring girls out there that not all guys consider it a negative trait, that your worry does nothing but bring wrinkles that neither of us wants to see. But I can, indeed should, draw a picture that is worth 1000 statistics.

Because I think an intelligent girl is the sexiest kind. It escapes me how people can cringe at the wonderful prospect of a Ph.D. marriage, in which both would go to school, come home early, and prepare (together, of course) a dinner with candles and roses and table cloth and wine glasses and Chopin’s Nocturne Op. 9 No. 2 playing in the background.

You’d talk about Truth and Beauty. You’d stand above real-life trivialities. You’d take her hand in yours, playing with the lovely fingers that you know so well, and look deep into her eyes whispering: “If Socrates had known you like I do, he wouldn’t have had so much trouble defining happiness.” Your fiance, actually knowing who Socrates is, would take that as the sweetest thing to say. She’d draw you nearer. You’d only object that it’s not nearly near enough. And you’d trace the contour of her face with both your fingers and your eyes, around the smiling lips, and towards her ears. You’d linger a half-second on her neck, and you would swiftly, swiftly, but gently…gently… lift her face near against yours. So near you can feel her gasping breath so tender that only Monet’s brushstroke can compare, and yet so wild that only inflation after the Asian 1997 crisis can rival.

Then, the moment of touch – and the world just stops making sense.

You’d finally nuzzle up to her ears, smile, and promise her an experience as stimulating as your earlier intellectual conversation, only of a different kind. (Camera refocuses onto the ceiling please. Light down please. Okay good.)

If that’s not Ph.D. love, I don’t know what is.

Either you can have that, or you can have the white-collar employee marriage, which involves hectic morning and spilled coffee and traffic jam and under-appreciative boss and over-compensate peers and traffic jam (again) and exhausted evening and left-overs (or take-outs) and, finally, bed (read: sleeping). All and all to prepare for, you know what, another hectic morning.

Of course the NOGPs can then turn the entire passage above into a scare campaign, featuring the poster below.

Oh well, at least my nuptial qualifications aren’t for you to judge, dudes.

It’s a simple question: should girls not attempt a Ph.D. so that she can have a better chance getting married?

– Milkie

Dear Milkie,

You clearly know how to pose a question to QA’s Q&A, asking about two things that I care the most: Ph.D. and girls, not ranked in that respective order. (Mom, just in case you’re reading, I love you too).

It’s amazing that the debate on over-educated females, if such a concept is even warranted, has never really reached a conclusion despite the unmistakable intelligence of the participants (it’s Ph.D. aspirants who are arguing, right?) I will thus hereafter attempt to lay the quarrel to rest, once and for all.

A final note must be made to justify my approach to solving the issue. I can easily write an ornate entry full of rhetoric so flowery, and emotions so contagious that upon finishing you’ll feel that life is not complete until you’ve taken the GRE. But that won’t put us an inch closer to resolving the debate, because if the question is to be raised again elsewhere, we can’t win an argument by proclaiming “But I feel so strongly about it!” Therefore, this entry won’t be crafted to indulge your literary taste buds, but to dissect, and lay bare, the faulty logical anatomy of every single no-PhD-for-girl argument that has been mounted. Of course, being no expert, I may miss one or two arguments, and is thus open to enlightenment. But the point remains: the debate can only be solved via point-by-point assessment. You can always skip to the point that perplex you the most, too.

Here we go, the third installment of the QA’s Q&A series.

________________________________

So, should girls not attempt a Ph.D. so that she can have a better chance getting married?

Without even delving into the argument, this question has already presupposed an erroneous assumption: girls are better off getting married. There are two ways you can justify this claim, both of which, as will be shown, are problematic.

1) Social constraints: society imposes a certain stigma over unmarried women, which translates into real and observable pressure, such from worried parents, over-solicitous aunts, or just gossip in the neighborhood. As I said, these pressures against women are admittedly real.

However, note that the question at heart is precisely whether we should change the social construct to free women of that stigma. To say  that we shouldn’t change the system, because that how the system currently functions, is to support your position with none but a reiteration of the position itself. This is also a classic example of the is-ought fallacy: how things are is not how things ought to be. (Illuminating example: a slave will be killed if he disobeys the system does not translate into slaves should therefore stay within the system.)

2) Some other objective reasons (e.g. biological): some argue that women are better off getting married because they are designed to be so, either psychologically, biologically or in some other objective manners. This argument admittedly circumvent the above fallacy.

And yet, isn’t the question whether women are better off best answered by women themselves? Aren’t they the one that have the most information about their preferences? Who are we to assume that we know the female mind better? Such is the an all-time fallacy in patriarchal arguments since the dawn of society, one that is particularly insidious because it clothes itself under the veneer of wanting the best for women.

Therefore, as demonstrated, the discouragement of girls getting Ph.D. starts out with a suspicious assumption right off the bat. But to stop the discussion here is too easy for the challenge to be interesting, and will also gloss over many interesting points raised by the camp of no-over-educated-girl-please (hereafter referred to as the NOGPs) So I will generously concede to you this assumption, so we can move on to substantive arguments.

More after the jump. Got a question? Email away at anh.le91 @ gmail.com

All of the NOGPs’ arguments can be said to converge in one point: attempting a Ph.D. will limit the girl’s chance of finding a spouse. After perusing the extensive scholarly literature on the topic (read Facebook), I can identify three major strands that support the point above. Please advice if I miss any.

1) Getting a Ph.D. makes you raise your standards too high.

2) Getting a Ph.D. makes you too intimidating to guys (in Vietnam, for the sake of convenience).

3) Getting a Ph.D. makes you miss that 20-something critical period for marriage.

Let’s roll up our sleeves, and dissect, X-ray, C-scan these arguments to see what lurks behind them.

________________________________________

1. Getting a Ph.D. makes you raise your standards too high.

An obvious, easy way to counter this argument is to claim that no, Ph.D. students aren’t snobby elitists that look down on people. But again, that’s too easy (and probably not too false either), so I won’t go down that road.

Now, if we follow the argument, it presupposes that raised standard is something bad. It limits your chance of getting married. So, may I humbly ask, isn’t the logical implication is that it’s best for us to lower our standards as much as possible, so that we can be content with whichever spouse we can get our hands on? Will that not maximize our chances of getting married, which is what NOGPs seem to prize so much?

At this point a NOGP can rightly protest: but that is reductio ad absurdum, man. The point is not to maximize to the extreme, but about a balance between the height of your standards and the scope of your potential match. If you raise the standards too high, the scope will become too small.

Yes, dear critic, it’s all about a balance, which is another way of saying that there is no fixed formula. When does the pool become too small? How do we know? Indeed, he satisfactory level of the scope is not even the same for every female, and yet we claim that everyone should go one way or another.

Honestly, whenever an argument comes down to balancing, it will always be a choice of the individual, who is best situated to know which distribution is good for him or her. Please take note, because this balancing issue will reappear.

2) Getting a Ph.D. makes you too intimidating to guys (in Vietnam, for the sake of convenience)

If we surgically examine the reason why a Ph.D. girl is intimidating to guys, and it turns out once again to be the social stigma, then please refer back to the first point in the assumption discussion. Guys will just be not intimidated any longer if we decide to change the system and remove the stigma. However, this is easy part.

What makes the argument much harder to counter is the reasonable claim that it is in their political interests for guys to not like over-educated girls. Once it is a matter of material interest, and no longer of social construct, then guys will forever not like over-educated women, turning having a Ph.D. into a real negative marital trait.

I will responsibly surrender to this argument. If indeed all guys are forever averse to Ph.D. girl, then, yeah – don’t get it, because having a Ph.D. then is just simply another negative trait like being extremely insensitive or annoying or whatever. There is nothing morally wrong with being annoying, but you shouldn’t be anyway, just because people will hate you.

But if not all, but only a majority of guys dislike Ph.D. girls, then the question boomeranged back to balancing, because the goal of a girl in life is not to be attractive to a majority of guys. She’ll have to judge for herself how widely appealing she’d like to be. Some can be perfectly happy with just the one (or the two – or the ten – depending on whom we’re talking about.)

3) Getting a Ph.D. makes you miss that 20-something critical period for marriage.

Why is that period critical?

Some argue that’s when parents nag all the times, friends get married all over, and you’ll pressured if not getting married. This social aspect has been dealt with above.

Others say that this is when most people are available for courting. I don’t understand why a 20-something Ph.D student is not court-able – I would even contend that she’s the sexiest kind (will do here). Considering the fact that as an employee, you’ll have to exhaust yourself plowing 8 hours a day in your cubicle, I wonder if that’s really the ideal environment for courting (vis-a-vis the lush greenery, ancient castles, and utmost tranquility of a university setting.)

Finally, a few argue that this period is biologically ripe for marriage. What does that mean, biologically ripe? If that’s about looks and stuff, I would say ~18 is the fullest – why not then? If that’s about procreative capability (gotta congratulate myself for coming up with the euphemism), well, I concede.

______________________________________________________________

Final words: As feminist as I sound in the post, anyone that knows me well can (unfortunately) testify against that. I only attempt to settle a pestilent debate here, trying to defend the truth, and not the females (my sincerest apology, ladies.) Thus, I am very open to any criticism about my argument, as well as any points made by the NOGPs that I did not mention.

After all, I care more about learning the truth than being the object of female affection. But that does not hurt either.

_____________________________________________________________

Update Nov. 15: A highly interesting and relevant article in The New Yorker, graciously introduced to us by Minh Trinh in the comments below 😀
“Hehe em vừa đọc được một bài rất cute về a PhD marriage. Nhân vật chính là Paul và Patricia Churchland (technically thì Paul là PhD còn Pat là B.Phil at Oxford). Đọc rất thú vị, kiểu hai bác gặp nhau trong academic context, woo nhau bằng knowledge và lấy nhau để complement each other’s studies. Họ nuôi dạy con trẻ bằng science và đối thoại với nhau bằng technical jargons. Tóm lại là as a couple they are both intellectually and emotionally fulfilled.”

The article can be viewed online at: http://thatmarcusfamily.org/philosophy/Course_Websites/Contemporary/Readings/Churchlands.pdf

Macfarquhar, Larissa. “Two Heads: a Marriage Devoted to the Mind-Body Problem.” New Yorker February 12, 2007,58-69.

Got a question? Email away at anh.le91 @ gmail.com

I am taking this class on globalization, reading “Bound Together: How Traders, Preachers, Adventurers, and Warriors Shaped Globalization” by Nayan Chanda. Here’s a question raised in an assignment:

In Chapter 6, Chanda shows how governments, nations, empires often make “claims to universalism”.  What does he mean?  Give specific examples of such “claims to universalism” that you know and critique them.

What are your take on the issue?
– Anh Thái

________________________________________

Lately, I’ve already been undertaking an obscene amount of reading (the intellectually provoking kinds, the likes of  “Organski’s Power Transition theory”, or “Gnial’s PvT Fast Stalker into Void Rays. ) And yet I did pick up and read the book, risking a severe case of acute word choking. So if I am to be found a dead corpse in my room, mouth foaming with knowledge and insights – dear lovers and friends, you guys know who to wage your revenge on. (Don’t worry, anh Thai, there aren’t that many.)

Anyhow, without further ado, here comes the second installment of the QA’s Q&A series.

________________________________________

Dear anh Thai,

There is the truth, and then there is politics. Let’s start with the easy thing first (i.e. politics)

Is it even surprising that empires have a penchant for universalist claims? In their rising stage, global empires need something to justify their expansionist policies – something ideal, something noble – something that rises beyond the morally unappealing pragmatism of booty and power. They need such something to unite and persuade their warriors and citizens as much as the conquered. For Plato, it is the idea that non-Greek barbaros (those who can’t speak Greek and only say what sounds like “bar bar”) are, well, barbarians and less than human. For Alexander the Great, it is his self-belief to be mankind’s arbitrator and reconciler sent by God. For Genghis Khan, it is simply the “God-given right” to conquer (Chanda 178, 185).

And for the U.S., I don’t know, perhaps it is the idea that “we are the greatest, best country that God has ever, ever, given man on the face of this Earth.”

Once an empire has secured its hegemonic status, it is no less politically motivated to employ universalist claims as a means to perpetuate the status quo. What is a better tool than a claim that simply demands, with little justification, universal submission to the values and order established by the empire itself? One can only expect secondary powers, or developing states, to appeal to the exactly opposite kind of rhetoric, one that emphasizes sovereignty and autonomy in the so-called “internal affairs.” This has been, unsurprisingly, the pattern in the human rights discourse between the U.S. and China, (or U.S. and Vietnam for that matter.)

So power politics is largely capable of explaining the empire’s and its resistors’ behaviors. But politics cannot answer the philosophical question: whether those universalist claims are true? Just because nations are politically motivated, doesn’t mean that their claims are necessarily false (just as your ex is emotionally motivated to say you’re a jerk, doesn’t mean that, well, she is not right.)

Luckily, some universalist claims are rather easily testable. Take, for example, the U.S. claim that it has a moral obligation to spread democracy, because democracies are more peaceful. All we need to do is to collect a bunch of data, and run a regression between being a democracy and the likelihood of going to war. The Correlates of War project, pioneered by Small and Singer, does precisely just that. The study concludes: democracies fight just as many, and just as bloody war. But, (an emphatic but) democracies do engage in less wars with one another. And yet again, maybe democracies fight less because they don’t share border for most of history, not because they are democracies (Small and Singer 67). Of course, we can then control for “contiguity” (or any other problematic variables) in your regression – that’s what scholars need to continue working on. The key point remains: whereas research has continued, and disagreement has yet to disappeared, on principle, the claim of “democratic peace” can be tested.

But what about claims such as that of universal human rights? Is it possible for countries to have its own version of “human rights” that suit their cultural and historical legacy? Or is human rights, as its name suggests, something every human is entitled to without difference? If so, who gets to decided which rights are universal?

These are philosophical questions that I’m not going to pretend that I can answer. I did broach the topic, arguing for the need for (not the existence of) universal values in a polemic entry against relativism. (See the exchange between me and anh neosvn towards the end of the comment section.) But that’s more like a call to arms – an urge to investigate, rather than a victorious declaration – a resolve of disputes. To answer these fundamental questions, we must enter into the debate of ontology (what are the nature of things?) and epistemology (how do we know what we know?) – in which philosophers have set up various camps throughout history. We have, to name a few, positivism (there is objective truth; and only what can be tested is true), constructivism (there is no objective truth; everything is socially constructed), and pragmatism (objective truth does not matter; theories are true if they help us accomplish practically) (Chernoff Ch. 3-4).

On the issue, I am not unlike a boy after his first day at school – fascinated, but utterly unlettered. So I will wisely stop now before I abuse my limited knowledge of the matter, like the boy babbling about how much he learns (or worse, knows) today. I have grown up way too much for that to be still considered cute.

Darn it.

___________________________________________

References

Chanda, Nyan. Bound Together: How Traders, Preachers, Adventurers, and Warriors Shaped Globalization. Yale University Press. 2007.

Chernoff, Fred. Theory and Metatheory in International Relations: Concepts and Contending Accounts. Palgrave Macmillan. 2007.

Small and Singer. “The War-Proneness of Democratic Regimes, 1816-1965”. The Jerusalem Journal of International Relations. Vol. 1, No. 4, Summer 1976.

Got a question? Ask away at anh.le91 @ gmail.com


text:
# The Game of Cop and Robbers

In the game of Cops and Robbers, there is a map consisting of nodes and edges.

• The cop and the robber are each on some node to begin with.
• The cop and the robber take turns to make moves.
• In each turn, the cop or the robber can either stay where he is, or go to a node that is connected by an edge.

The cop wins if he can manage to capture the robber, i.e. be in the same vertex as the robber.

Here are a few maps on which Cops and Robbers can be played:

On one of these maps, it is never possible for the cop to win if the robber plays well. Which one is it?

×

format: plain


text:
745 pág.

# Livro CURRENT Diagnosis & Treatment In Family Medicine

Disciplinamobiliário15 materiais3 seguidores
Pré-visualização50 páginas
```a LANGE medical book
CURRENT
Diagnosis &
Treatment in
Family Medicine
second edition
Jeannette E. South-Paul, MD
Andrew W. Mathieson Professor and Chair
Department of Family Medicine
University of Pittsburgh School of Medicine
Pittsburgh, Pennsylvania
Samuel C. Matheny, MD, MPH
Professor and Nicholas J. Pisacano, MD, Chair
of Family Medicine
Department of Family and Community Medicine
University of Kentucky College of Medicine
Lexington, Kentucky
Evelyn L. Lewis, MD, MA
Director, Healthcare Policy
P\ufb01zer, Inc.
Bowie, Maryland
Departments of Family Medicine and Medical
and Clinical Psychology
Uniformed Services University of the Health Sciences
Bethesda, Maryland
New York Chicago San Francisco Lisbon London Madrid Mexico City
New Delhi San Juan Seoul Singapore Sydney Toronto
States of America. Except as permitted under the United States Copyright Act of 1976, no part of this publi-
cation may be reproduced or distributed in any form or by any means, or stored in a database or retrieval sys-
tem, without the prior written permission of the publisher.
0-07-151004-4
The material in this eBook also appears in the print version of this title: 0-07-146153-1.
occurrence of a trademarked name, we use names in an editorial fashion only, and to the benefit of the trade-
mark owner, with no intention of infringement of the trademark. Where such designations appear in this book,
they have been printed with initial caps.
McGraw-Hill eBooks are available at special quantity discounts to use as premiums and sales promotions, or
george_hoare@mcgraw-hill.com or (212) 904-4069.
This is a copyrighted work and The McGraw-Hill Companies, Inc. (\u201cMcGraw-Hill\u201d) and its licensors reserve
all rights in and to the work. Use of this work is subject to these terms. Except as permitted under the
Copyright Act of 1976 and the right to store and retrieve one copy of the work, you may not decompile, dis-
assemble, reverse engineer, reproduce, modify, create derivative works based upon, transmit, distribute, dis-
seminate, sell, publish or sublicense the work or any part of it without McGraw-Hill\u2019s prior consent. You may
use the work for your own noncommercial and personal use; any other use of the work is strictly prohibited.
Your right to use the work may be terminated if you fail to comply with these terms.
THE WORK IS PROVIDED \u201cAS IS.\u201d McGRAW-HILL AND ITS LICENSORS MAKE NO GUARAN-
TEES OR WARRANTIES AS TO THE ACCURACY, ADEQUACY OR COMPLETENESS OF OR
RESULTS TO BE OBTAINED FROM USING THE WORK, INCLUDING ANY INFORMATION THAT
CAN BE ACCESSED THROUGH THE WORK VIA HYPERLINK OR OTHERWISE, AND EXPRESSLY
DISCLAIM ANY WARRANTY, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO
IMPLIED WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.
McGraw-Hill and its licensors do not warrant or guarantee that the functions contained in the work will meet
your requirements or that its operation will be uninterrupted or error free. Neither McGraw-Hill nor its licen-
sors shall be liable to you or anyone else for any inaccuracy, error or omission, regardless of cause, in the
work or for any damages resulting therefrom. McGraw-Hill has no responsibility for the content of any infor-
mation accessed through the work. Under no circumstances shall McGraw-Hill and/or its licensors be liable
for any indirect, incidental, special, punitive, consequential or similar damages that result from the use of or
inability to use the work, even if any of them has been advised of the possibility of such damages. This lim-
itation of liability shall apply to any claim or cause whatsoever whether such claim or cause arises in contract,
tort or otherwise.
DOI: 10.1036/0071461531
We hope you enjoy this
McGraw-Hill eBook! If
its author, or related books and websites,
Professional
We would like to dedicate this book
to all family physicians who deliver care in austere environments,
especially our colleagues in uniform, and the families that support them.
Jeannette E. South-Paul, MD
Samuel C. Matheny, MD, MPH
Evelyn L. Lewis, MD, MA
v
Contents
Authors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ix
Preface. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xvii
SECTION I: INFANCY & CHILDHOOD
1. Well Child Care . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1
Sukanya Srinivasan, MD, MPH, & Donald B. Middleton, MD
2. Failure to Thrive. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .13
Deborah Auer Flomenhoft, MD
3. Neonatal Hyperbilirubinemia . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .21
Andrew B. Symons, MD, MS, & Martin C. Mahoney, MD, PhD, FAAFP
4. Breast-feeding & Infant Nutrition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .29
Tracey D. Conti, MD
5. Common Infections in Children . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .36
Mark A. Knox, MD
6. Skin Diseases in Infants & Children . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .53
Mark A. Knox, MD
7. Routine Childhood Vaccines . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .63
Richard Kent Zimmerman, MD, MPH, Donald B. Middleton, MD, & Sanford R. Kimmel, MD
8. Disruptive Behavioral Disorders in Children. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .72
William S. Sykora, MD, COL, USAF, MC
9. Seizures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .88
Donald B. Middleton, MD
10. Physical Activity in Adolescents. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .103
Mark B. Stephens, MD, MS, FAAFP
11. Eating Disorders . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .113
Evelyn L. Lewis, MD, MA, & Tracy Sbrocco, PhD
12. Adolescent Sexuality . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .124
Margaret R. H. Nusbaum, DO, MPH, & Peter J. Katsufrakis, MD, MBA
13. Menstrual Disorders . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .133
Mary V. Krueger, DO, MPH, MAJ, MC, USA
14. Sexually Transmitted Diseases . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .146
Peter J. Katsufrakis, MD, MBA, & Kimberly A. Workowski, MD, FACP


text:
# Vertical spacing with outlines package

I am using the outlines package with the tufte-book class, which places footnotes in the margin. I want the first line an outline item to begin after the last line of any footnote generated by the previous item. The code below provides more details.

\documentclass{tufte-book}
\usepackage{outlines}
\begin{document}
\begin{outline}[enumerate]
\1 First item\footnote{A footnote with more than one line. Notice the horizontal location of the first sub item (item 1(a)). }
%  \vspace{12pt}%
\2 First subitem: I need to add vertical space to make this item begin after the below the last line of the footnote; you can see what I mean by exposing the command \verb!\vspace{12pt}! in the code for this example and reformatting; I would like to automate this process
\2 Some items may contain more than one \footnote{First footnote.} footnote,\footnote{An empty line follows this footnote.} or empty lines, which may further complicate incorporating automated spacing\footnote{I added a spacing command after this item.}
\vspace{5pt}%
\2 There are no spacing problems when the number of lines in an outline item is equal to or larger than those (including empty lines) in footnotes generated in the item text\footnote{A footnote after two empty lines.}
\2 So, the spacing problem only occurs when the number of lines in a footnote, or sequence of footnotes and empty lines, exceeds the number of lines in the item generating the footnote(s)
\1 In summary, I would like to automate the process of adding sufficient space (when necessary) after a current outline item-footnote pair so that the next item begins below the last line of that pair
\2 A solution requires calculating and adding the necessary space
\end{outline}
\end{document}


text:
# Why is it twice as expensive to make a noise function that can be tiled?

I've seen in several places that making Perlin noise loop seamlessly requires calculating it twice in slightly different ways, and summing the two results.

This Perlin noise math FAQ gives a formula:

$$F_{loop}(x, y, z) = \frac{ (t - z) \cdot F(x, y, z) + z \cdot F(x, y, z - t) }{ t}$$

to make a noise function $F$ loop in the $z$ direction. It also mentions that extending this, to loop in 2 dimensions would take 4 evaluations of $F$ and to loop in 3 dimensions would take 8 evaluations of $F$.

I understand that this gives a seamless join between tiles that is not only continuous but continuously differentiable, but I intuitively expect that to be the case if the noise function is simply evaluated once with grid points reduced modulo the required tile size. If the noise function is only ever based on the immediately surrounding grid points (4 for 2D noise, 8 for 3D noise) then surely just using the leftmost grid points when the point to calculate gets past the right hand edge of the tile will give the same quality of noise as between any other grid points?

Since I've seen this multiple calculation approach in several places I assume it must have some advantage, but I'm struggling to see the disadvantage with simply wrapping the grid points back to the start when they get too big. What am I missing?

It's unfortunate that people commonly recommend this. Blending between two (or four, etc.) translated copies of a noise function in that way is a pretty bad idea. Not only is it expensive, it doesn't even produce correct-looking results!

On the left is some Perlin noise. On the right is two instances of Perlin noise, stacked and blended left-to-right.

The difference is kind of subtle, but you can see that the second image has lower contrast in a vertical column running down the middle. That's where it's a 50% blend between two different instances of the noise function. Such a blend doesn't look like the original noise function: it just looks like a muddy mess.

OK, so it's not quite that bad just looking at the raw noise...but if you then do any nonlinear transformations on the image, the nonuniform contrast can cause issues. For instance, here are those images thresholded at 60%. (Think of generating islands in an ocean, for instance.)

Now you can plainly see how the image on the right has fewer, smaller white areas in the middle.

Like you mentioned, for grid-based noise like Perlin, a better way is to tile the pseudorandom gradients at the grid points. That's easy and cheap to do, and then you can apply the interpolation algorithm to the gradients as usual (much like bilinear interpolation of a tiling texture). This produces tiling noise without any weird artifacts, because it works with the underlying noise algorithm rather than over the top of it. You can use a similar strategy with Worley noise (cellular noise) by tiling the random feature points it uses as a basis.

With multiple octaves of noise it's not always so easy, though. If the relative scale between the octaves (aka "lacunarity") isn't an integer or simple rational number, then you may not be able to find a convenient tiling point where all the octaves' grids match up. You could tile each octave independently, but the overall noise would still not be tilable in that case.

• Side by side images really make a difference for getting an intuitive feel for the explanation. I'm going to bear this in mind for my own answers. – trichoplax Aug 15 '15 at 9:49


text:
# janmr blog

## Good Rational Bounds07 January 2013

Say we have a k-bit integer and we want to allocate a character array to hold the decimal digits of this number. How large must the array be? Well, the exact formula is

but we are concerned about efficiency and don't want to use floating point calculations. So we fire up a calculator and get . This means that we can use, e.g., as an upper bound for and allocate characters. But we are also concerned about memory and think it is a waste to use little more than 10% more memory than needed. We could just use as an upper bound, but we don't want to use too large constants because we are also concerned about arithmetic overflow.

This is where continued fractions come in, see an earlier post for some basic notation and properties. Let where all are non-negative integers. Such a representation has some very desirable properties regarding rational approximations and bounds (the “truncated” continued fraction for is called the th convergent of ):

1. The even convergents are always less than . Similarly, the odd convergents are always greater than .
2. The th convergent is a very good rational approximation to . (We will not make this statement exact, but just say that a rational fraction is a best approximation if every other rational fraction with the same or smaller denominator differs from by a greater amount.)

We will now apply these facts to our example. We start by obtaining any rational upper bound with the restriction that it must be tighter than the good rational bound that we are aiming for. We have and we compute the continued fraction for this upper bound,

We now begin to compute the odd convergents, and keeping an eye on how tight they are:

• (too much by about 11%)
• (too much by about 0.015%)
• (too much by about 0.00031%)

There are more odd convergents to consider, but we probably don't need to go any further for this use case. So we can allocate characters, knowing that it is a very tight upper bound.

(Note how a similar approach could be used if we were looking for a lower bound instead.)


text:
Lemma 29.16.2. Let $S$ be a scheme. Let $A$ be an Artinian local ring with residue field $\kappa$. Let $f : \mathop{\mathrm{Spec}}(A) \to S$ be a morphism of schemes. Then $f$ is of finite type if and only if the composition $\mathop{\mathrm{Spec}}(\kappa ) \to \mathop{\mathrm{Spec}}(A) \to S$ is of finite type.

Proof. Since the morphism $\mathop{\mathrm{Spec}}(\kappa ) \to \mathop{\mathrm{Spec}}(A)$ is of finite type it is clear that if $f$ is of finite type so is the composition $\mathop{\mathrm{Spec}}(\kappa ) \to S$ (see Lemma 29.15.3). For the converse, note that $\mathop{\mathrm{Spec}}(A) \to S$ maps into some affine open $U = \mathop{\mathrm{Spec}}(B)$ of $S$ as $\mathop{\mathrm{Spec}}(A)$ has only one point. To finish apply Algebra, Lemma 10.54.4 to $B \to A$. $\square$

In your comment you can use Markdown and LaTeX style mathematics (enclose it like $\pi$). A preview option is available if you wish to see how it works out (just click on the eye in the toolbar).


text:
## Theorem

Let $\left({X, \Sigma, \mu}\right)$ be a measure space.

Then $\mu$ is strongly additive, that is:

$\forall E, F \in \Sigma: \mu \left({E \cap F}\right) + \mu \left({E \cup F}\right) = \mu \left({E}\right) + \mu \left({F}\right)$

## Proof

$\blacksquare$


text:
Chained Clauser–Horne–Shimony–Holt inequality for Hardy’s ladder test of nonlocality

Chained Clauser–Horne–Shimony–Holt inequality for Hardy’s ladder test of nonlocality Relativistic causality forbids superluminal signaling between distant observers. By exploiting the non-signaling principle, we derive the exact relationship between the chained Clauser–Horne–Shimony–Holt sum of correlations $$\text {CHSH}_K$$ CHSH K and the success probability $$P_K$$ P K associated with Hardy’s ladder test of nonlocality for two qubits and $$K+1$$ K + 1 observables per qubit. Then, by invoking the Tsirelson bound for $$\text {CHSH}_K$$ CHSH K , the derived relationship allows us to establish an upper limit on $$P_K$$ P K . In addition, we draw the connection between $$\text {CHSH}_K$$ CHSH K and the chained version of the Clauser–Horne (CH) inequality. http://www.deepdyve.com/assets/images/DeepDyve-Logo-lg.png Quantum Information Processing Springer Journals

Chained Clauser–Horne–Shimony–Holt inequality for Hardy’s ladder test of nonlocality

, Volume 15 (4) – Dec 23, 2015
14 pages

Publisher
Springer US
Subject
Physics; Quantum Information Technology, Spintronics; Quantum Computing; Data Structures, Cryptology and Information Theory; Quantum Physics; Mathematical Physics
ISSN
1570-0755
eISSN
1573-1332
D.O.I.
10.1007/s11128-015-1217-4
Publisher site
See Article on Publisher Site

DeepDyve is your personal research library

It’s your single place to instantly
that matters to you.

over 12 million articles from more than
10,000 peer-reviewed journals.

All for just $49/month Explore the DeepDyve Library Unlimited reading Read as many articles as you need. Full articles with original layout, charts and figures. Read online, from anywhere. Stay up to date Keep up with your field with Personalized Recommendations and Follow Journals to get automatic updates. Organize your research It’s easy to organize your research with our built-in tools. Your journals are on DeepDyve Read from thousands of the leading scholarly journals from SpringerNature, Elsevier, Wiley-Blackwell, Oxford University Press and more. All the latest content is available, no embargo periods. Monthly Plan • Read unlimited articles • Personalized recommendations • No expiration • Print 20 pages per month • 20% off on PDF purchases • Organize your research • Get updates on your journals and topic searches$49/month

14-day Free Trial

Best Deal — 39% off

Annual Plan

• All the features of the Professional Plan, but for 39% off!
• Billed annually
• No expiration
• For the normal price of 10 articles elsewhere, you get one full year of unlimited access to articles.

$588$360/year

billed annually

14-day Free Trial


text:
# Trailblazer has good ideas hidden by Object Oriented Programming

(written by lawrence krubner, however indented passages are often quotes). You can contact lawrence at: lawrence@krubner.com

Trailblazer for Ruby On Rails has some very good ideas in it though they are somewhat buried by the Object Oriented programming garbage:

To give an example of how operation works, let’s say you click on a delete button. What happens when you do that is you go to the control that knows a little bit of this action because it does authentication—if it’s valid it does one thing and if it’s not it does another thing. Instead of delegating to a model that has 10 lines of code delegating to different models and eventually ends up needing three layers of application code, the controller in the Trailblazer framework will delegate this delete action to a service object. You can have as many operations as you want.

That sounds similar to what I try to do with my Clojure code, but my Clojure code tends to get a hashmap, and polymorphically dispatches on what is in that hashmap. The result is very similar, but I don’t have to deal with all the object hierarchy stuff. The key idea here is polymorphic dispatch, and that is a good idea, but I feel like Trailblazer is forced to bury some of that goodness under a thick blanket of Object Oriented Programming.

Trailblazer reintroduces object-orientation.

For each public action, there’s one operation class.

Operations inherit contract, policies, representers, etc. and can be fine-tuned for their use case.

This seems to be a common refrain among those who do Object Oriented Programming — those other people are not doing it right, but if you do it the way that we do it, then you will like it, because we are doing True Object Oriented Programming!!!!

This example is offered:

 class Comment::Update < Create
policy do
is_owner?(model)
end
end

Nick Gorbikoff says the fun is back:

I haven't been this excited about Rails since 2007! Trailblazer - makes Rails development fun again. Especially on large projects. It's one of the better implementations of the ServiceObject / ViewModel / Form Object / Policy layers I've seen, which sooner or later ( rather sooner) you'll need.

But where did the fun go, and why is the fun in such need of frequent rescue? If Object Oriented Programming was a good idea, would it need these frequent efforts at reform, renewal, and rebuilding? Many talented programmers have devoted absurd amounts of time to saving various Object Oriented Programming projects, and so one inevitably ends up encountering some good ideas in these projects, and yet one also runs into the constant feeling that this is some kind of hard struggle.

Rather sad to consider what the initial impetus was:

For the last few years I’ve been hired from different companies to refactor messed up Rails applications, and one of the most common problems I’ve run into are legacy projects with huge models of PHP scripts put into a Ruby model, where all the domain, rendering, processing, validation and etcetera are put in the model. Another one I’ve run into are horrible view layers, where the partials weren’t encapsulated and therefore every partial had access to every variable, which ends up in a messy view layer.

Source


text:
# How to explain or understand ''a function's infinity norm''

Dear all,

I am sorry to bother you. Recently, I have been learning convex optimization and The DCP Rulerset. I clearly understand that I must prove the function is convex before using CVX. That’s difficult.

As we all know, p-norm is convex when p\geq 1 and that is easy to prove according to the properties of the norm.

But I have an optimization problem shown as follows:

g_1(w|m_1,c_1,k_1,m_2,c_2,k_2)=\\ \frac{-m_2w^2+k_2+jc_2w}{\{m_1m_2w^4-(m_1k_2+m_2k_1+m_2k_2+c_1c_2)w^2+k_1k_2\} +j\{-[m_1c_2+m_2(c_1+c_2)]w^3+(c_2k_1+c_1k_2)w\}}
\begin{aligned} &\underset{c_2,k_2,h}{min}\ \ h \\ &subject\ \ to:\ \ ||g_1(w|m_1,c_1(i),k_1(i),m_2,c_2,k_2)||_\infty \leqslant h,\ i=1,...,500 \end{aligned}

where w is a constant vector, m_1,c_1(i),k_1(i),m_2 are constants, c_2,k_2 are scalars.

I just cannot understand a function’s infinity norm means in mathematics. I tried to find some helpful information but failed. So I want to know how to learn the a function’s infinity norm and prove it is convex or not.

Thank you very much in advance.

The Markdown code cannot display all the equations, so I paste the picture.

The infinity norm of a vector is the maximum of the absolute value of the elements of the vector.The infinity norm of an affine argument is convex. The infinity norm is so named because it is the limit of the p-norm as p goes to infinity.

If x is a vector, its infinity norm in CVX can be expressed as norm(x,inf)

The infinity norm of a an affine matrix M is also convex, and is accepted by CVX as norm(M,inf) .

Dear Mark,
Thank you very much! I understand what you said. However, I am still confused about my problem. To my shallow understanding, if c2, k2 are not the variables, g1(w) is a vector without question; but right now c2, k2 are variables, g1(w) is a function of c2, k2. I tried to use norm(g1(w), inf) and some error happened.

clear
clc
% number of variable
d = 3;
% confidence parameter
Beta = 1e-10;
% violation parameter
Epsilon = 0.1;
N = ceil(2 / Epsilon * (log(1/Beta)+d));
% define constants
m1 = 10;
m2 = 0.5;
w1 = 2*pi*50;
zeta1 = 0.01;
% sampling of uncertain parameter
c1 = rand(1,N) * (2*m1*w1*zeta1 - 0) + 0;
k1 = rand(1,N) * (1.2*m1*w1^2 - 0.8*m1*w1^2) + 0.8*m1*w1^2;
% discretization of angular frequency
M = (70-30)/0.1;
w = linspace(30*2*pi,70*2*pi,M);
%% CVX part
cvx_begin
variables c2 k2 h
minimize(h)
subject to
c2>=1e-5;
k2>=1;
for j = 1:N
norm(((-m2*w.^2+k2+1i*c2*w)./((m1*m2*w.^4-(m1*k2+m2*k1(j)+m2*k2+c2*c1(j))*w.^2+k2*k1(j))+1i*(-(m1*c2+m2*(c1(j)+c2))*w.^3+(c2*k1(j)+c1(j)*k2)*w))), inf) <= h;
end
cvx_end

warning: A non-empty cvx problem already exists in this scope.
It is being overwritten.

error use  .*  (Line 173)
Disciplined convex programming error:
Cannot perform the operation: {complex affine} ./ {complex affine}

error  ./  (Line 19 ) z = times( x, y, './' );

error Untitled2 (Line 30)
norm(((-m2*w.^2+k2+1i*c2*w)./((m1*m2*w.^4-(m1*k2+m2*k1(j)+m2*k2+c2*c1(j))*w.^2+k2*k1(j))+1i*(-(m1*c2+m2*(c1(j)+c2))*w.^3+(c2*k1(j)+c1(j)*k2)*w))),
inf) <= h;

g1(w) is not an affine expression, hence CVX does not allow its norm to be used. It doesn’t even allow g1(w)` to be formed.

it appears that “your” problem is not convex.


text:
Aircell Gets $176 Million for In-flight Broadband Aircell, the Itasca, Ill. company behind the wildly hyped GoGo in-flight broadband, has raised$176 million in funds from an undisclosed group of investors. (Don’t worry — we asked, but they wouldn’t tell us who invested in the company.) The funds will be used for network expansion, among other things.

GoGo, which is currently available on more than 700 commercial aircraft, and has commitments from a total of nine airlines, needs to build out its network aggressively if it wants hype to meet match reality. As it has grown, GoGo’s connection quality has declined as the strain on its network has gone up because of increased usage.

In many ways, the hype around GoGo has met reality. The uptake of the service is pretty low at present. Some say it might be as low as six users per flight. I think the pricing has something to do with the reason why many travelers are not so keen on paying for in-flight broadband just yet. The low uptake might be the reason why Aircell is figuring out a way to sell the service to the carriers itself for more backend functions. The good news — if you can call it that — is that the competing Row44 service (on Southwest) is actually worse off.


text:
# setting the frequency of a PWM on a STM32

I'm trying to write a function that takes a desired frequency of PWM and sets the timer based on this value:

void initTimer(unsigned int freq ){

RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM3, ENABLE);

TIM_TimeBaseInitTypeDef timerInitStructure;
timerInitStructure.TIM_Prescaler = 1000;
timerInitStructure.TIM_CounterMode = TIM_CounterMode_Up;
timerInitStructure.TIM_Period = 1000;
timerInitStructure.TIM_ClockDivision = TIM_CKD_DIV1;
timerInitStructure.TIM_RepetitionCounter = 0;
TIM_TimeBaseInit(TIM3, &timerInitStructure);
TIM_Cmd(TIM3, ENABLE);

TIM_OCInitTypeDef outputChannelInit;
outputChannelInit.TIM_OCMode = TIM_OCMode_PWM1;
outputChannelInit.TIM_Pulse = 500;
outputChannelInit.TIM_OutputState = TIM_OutputState_Enable;
outputChannelInit.TIM_OCPolarity = TIM_OCPolarity_High;
// the first channel
TIM_OC1Init(TIM3, &outputChannelInit);
GPIO_PinRemapConfig(GPIO_FullRemap_TIM3,ENABLE);

}

The code works fine and generates the expected PWM. My Problem is that I don't know how to calculate the value of the prescaler based on the given frequency. In the example above the values are fixed.

Any idea how may I do this? Thanks in advance!

• Read the datasheet/programming reference guide for your chip. Specifically the section about PWM. It has it all. If you can't find it, look for some application notes (yes, I know, STMs docs are somewhat difficult to navigate..). – Eugene Sh. Jun 23 '15 at 14:18

In short, you want to satisfy the equation:

Prescaler * Overflow = Period-in-Cycles = Clock-cycles-per-Second / Frequency

A good way to calculate the prescaler and overflow values for PWM is to chose the smallest possible prescaler, then trim down the overflow to the desired total frequency. This keeps the overflow value as large as possible, which then gives the most precision if you later want to modulate the duty cycle of the waveform.

For example, if the clock frequency is 72 MHz and you want a 250 Hz output square wave (50% duty), then the total output waveform period in clock cycles (period_cycles) would be 72 MHz / 250 Hz = 288000 cycles. The timer's overflow value is usually 16-bits at most (0xFFFF, or 65535), the prescaler must be such that prescaler * overflow >= period_cycles, and 288000.0 / 0xFFFF => 4.39459..., so the prescaler should be 5. Finally, 288000 / 5 => 57600, which is a nice round number for the overflow (you would want to round this to the nearest integer if it wasn't).

Here's some code implementing the above algorithm, including appropriate rounding using C integer arithmetic:

#define CLOCK_CYCLES_PER_SECOND  72000000

uint32_t period_cycles = CLOCK_CYCLES_PER_SECOND / freq;
uint16_t prescaler = (uint16)(period_cycles / MAX_RELOAD + 1);
uint16_t overflow = (uint16)((period_cycles + (prescaler / 2)) / prescaler);
uint16_t duty = (uint16)(overflow / 2);

Of course, in your actual code you'll want to check for edge cases like freq == 0 or freq > CLOCK_CYCLES_PER_SECOND/2.

• I always did this way from head, but it is good to have this nicely written. – Darko Apr 18 at 20:44
• If you do not want 50% duty, it can be calculated like duty = overflow * percent_duty / 100. – Darko Apr 18 at 20:50

To expand on Eugene's comment ... in the datasheet the relevant sections are about clocks (there's a nice diagram how they're derived) and PWM. And there's possibly also a document describing the library that you use (FWLib or what is it?).

Your init code shows that timer/PWM clock is derived from PCLK1 (APB1), which is normally cpu clock divided by something. There are functions to get clocks (RCC_xxx), so you can get the number. After that you basically have two dividers, Prescaler and Period, so you get PCLK1/1000000.


text:
Chern classes of birational varieties

Paolo Aluffi

Let $\varphi: V\dashrightarrow W$ be a birational map between smooth algebraic varieties which does not change the canonical class (in the sense of Batyrev). We prove that the total homology Chern classes of $V$ and $W$ are push-forwards of the same class from a resolution of indeterminacies of $\varphi$.

For example, it follows that the push-forward of the total Chern class of a crepant resolution of a singular variety is independent of the resolution.


text:
# Is the family of equivalent norms a locally compact space?

Consider an infinite dimensional Banach space $$(X,||\cdot||)$$. Let $$\mathcal{P}$$ be the family of all equivalent norms in $$X$$. That is $$p\in \mathcal{P}$$ iff $$p$$ is equivalent to $$||\cdot||$$, i.e. there exists two constants $$c_1,c_2>0$$ such that $$c_1||x||\leq p(x)\leq c_2||x||$$ for all $$x\in X$$.

$$\mathcal{P}$$ is a metric space endowed with the following metric $$\rho$$:

$$\rho(p,q)=\sup_{||x||\leq 1} \lbrace |p(x)-q(x)|\rbrace$$

$$\mathcal{P}$$ is a Baire space, seen as an open subset of the space of all continuous semi-norms in $$(X,||\cdot||)$$ with the same metric $$\rho$$. This last space is a complete metric space, so by the Baire category theorem it is a Baire space.

Is $$\mathcal{P}$$ a locally compact space? - We can't use Riesz Lemma, as this space is not a linear space, to argue against the locally compactness.

• what does "the family of all equivalent norms" mean?? you're looking at all norms but consider two to be equal in $\mathcal{P}$ if they are equivalent? – mathworker21 Sep 30 '18 at 10:23
• @mathworker21 An element $p\in \mathcal{P}$ means that it is equivalent to $||\cdot||$, i.e. there exists two constants $c_1,c_2>0$ such that $c_1||x||\leq p(x)\leq c_2||x||$ for all $x\in X$ – Chazz Oct 1 '18 at 4:06

No, here is a counterexample. Take $$X=L^1(\mathbb{R})$$, $$\|.\|_1$$ the usual $$L^1$$ norm.

By contradiction, assume $$\mathcal{P}$$ to be locally compact. Then there exists a compact neighbourhood $$K$$ of $$\|.\|$$ which is compact. Let $$\epsilon>0$$ be such that $$B(\|.\|_1,2\epsilon)$$ is a subset of $$K$$.

Define for $$f \in X$$, $$p_n(f)=\int_{\mathbb{R}} |f(t)|\left(1+\epsilon e^{-(t-n)^2}\right)dt.$$

These norms are equivalent to $$\|.\|_1$$ (with $$c_1=1$$ and $$c_2=1+\epsilon$$).

Clearly, $$\rho(p_n,\|.\|_1)\leq \epsilon$$ and in fact there is equality (by considering a sequence $$(f_k)_k$$ of approximation of unity around $$t=n$$).

Since $$p_n \in K$$ for every $$n$$, one can extract a subsequence converging. However, no extracted sequence of $$(p_n)_n$$ is a Cauchy sequence: for every $$n$$, $$\lim_{m\to +\infty} \rho(p_n,p_m)\geq \epsilon,$$ again by considering a sequence $$(f_k)_k$$ of approximation of unity around $$t=n$$. This yields a contradiction.

• Great! Do you know if there are examples where $\mathcal{P}$ is indeed a locally compact space? – Chazz Oct 1 '18 at 19:19
• I would be surprised if there is, but truth is I don't know. – user120527 Oct 2 '18 at 7:59
• I was wondering if this argument can be modified to actually prove that for all Banach spaces $(X, ||\cdot||)$, the family of all equivalent norms is NOT locally compact? – Chazz Oct 5 '18 at 0:04


text:
# Existence of ergodic measure for measurable maps

The existence of ergodic measures is usually proved under the assumptions that the space $\Omega$ is compact metric and the transformation $T: \Omega \rightarrow \Omega$ is continuous, by using results on the existence of extreme points. Is it possible to establish the existence of ergodic measures if $T: \Omega \rightarrow \Omega$ is only a measurable transformation? ($\Omega$ can still be assumed compact metric.) If not, is there any extra condition that would be sufficient for this (of course, weaker than continuity of $T$)?

-
Measurability alone is not enough to guarantee existence of invariant (or ergodic) measures. See math.stackexchange.com/questions/94981/… and mathoverflow.net/questions/66669/… – Vaughn Climenhaga Aug 14 '13 at 19:06
$x\mapsto x+1$ in $\mathbb{R}$ is the standard counterexample, if you want $\Omega$ to be compact you can take $[0,1]$ with $T\colon x\mapsto x/2$ for $x>0$ and $T(0)=1$. – Vaughn Climenhaga Aug 14 '13 at 19:07
Great, thanks. But would then a sufficient condition be the existence of an invariant measure? – John Learner Aug 14 '13 at 19:45
Yes, if $T$ is a measurable transformation and $\mu$ is a $T$-invariant measure, then there must exist an ergodic measure. This is using the ergodic decomposition, see for example this question: mathoverflow.net/q/124066/5701 – Vaughn Climenhaga Aug 14 '13 at 20:05

As indicated in the comments, measurability alone is not enough, and there are easy counterexamples.

As for a condition between continuity and measurability that still does the trick, I'm not sure if there's a natural one. Using Lusin's theorem one can prove that Condition (C) below is equivalent to existence of an invariant measure, but it's not a particularly pleasant condition, as you'll see. Here we assume that $\Omega$ is a complete separable metric space (not necessarily compact), and $f\colon \Omega\to \Omega$ is measurable (nothing more yet...)

(C) There exist a sequence of points $x_k\in \Omega$ and times $n_k\in \mathbb{N}$ such that for every $\epsilon>0$ there is a compact set $K_\epsilon\subset \Omega$ satisfying: (1) $f|_K$ is continuous, and (2) $\#\{1\leq j\leq n_k \mid f^j(x_k) \in K_\epsilon\} \geq (1-\epsilon)k$ for all sufficiently large $k$.

If you have an invariant measure, you can use the ergodic decomposition to get an ergodic measure, and then the Birkhoff ergodic theorem together with Lusin's theorem to show that (C) holds. On the other hand, if (C) holds then by considering the empirical measures $\mu_k = \frac 1{n_k} \sum_{j=0}^{n_k} \delta_{f^jx_k}$ one can observe the following:

1. $\mu_k(K_\epsilon)>1-\epsilon$ for all $\epsilon$ and all large $k$, and hence the sequence $\mu_k$ is tight, so by Prohorov's theorem it has a convergent subsequence $\mu_{k_i}\to \mu$.
2. If $D$ is a metric on the space of probability measures on $\Omega$ that induces the weak* topology, then $D(\mu, f_*\mu) \leq D(\mu,\mu_k) + D(\mu_k,f_*\mu_k) + D(f_*\mu_k,f_*\mu)$. The first term goes to zero along $k_i$ by the assumption on the subsequence. The second term goes to zero along $k$ because the empirical measures are averages over long orbit segments. The third term goes to zero because $f$ is continuous on $K_\epsilon$ and both $\mu$ and $\mu_k$ put nearly all their weight on $K_\epsilon$. Thus $D(\mu,f_*\mu)=0$ and so $\mu$ is $f$-invariant.

So (C) is equivalent to the existence of an invariant measure. It's not a terribly nice-looking condition, though. At the very least you can probably use this to cover some reasonable classes of examples.

-


text:
# [Tex/LaTex] How to remove section name from frametitle header in cambrigeus style

beamerheader-footersectioning

\documentclass[xcolor=table]{beamer}
\mode<presentation> {
\usetheme{CambridgeUS}
\usecolortheme{dolphin}
\setbeamertemplate{navigation symbols}{}
}
\usepackage{graphicx} % Allows including images
\usepackage{booktabs}
\section{Motivation}
\section{Introduction}
\section{State of the Art Development}
\section{Problem Statement}
\section{References}

\begin{frame}
\frametitle{Motivation}
\begin{itemize}
\item 3.4 billion   smart-phone shipped worldwide [1].
\item Pervasive usage of mobile devices has  enabled  fast growth of mobile applications.
\item  Mobile devices  have increasing CPU speed and memory size, are not as capable as modern  desktop computers when running applications.
\end{itemize}
\end{frame}
\begin{frame}

\frametitle{Introduction}
\begin{itemize}
\item Computation offloading is a procedure that migrates resource-intensive computations from a mobile device to the resource-rich cloud, or server (called nearby infrastructure)[2].
\item An integration of cloud computing technology with mobile devices to make the mobile devices resource full in terms of computational power, memory, storage and energy[3]
\end{itemize}
\end{frame}

I am using cambridgeUS style .On every page last section name is shown.I don't want on every slide section name to be represented .For example last section name reference is shown on every slide .I want to remove it.Kindly help me in this regard .Googled alot in this context.
Thanx

#### Best Answer

The easiest way could be to use \section[]{Motivation} because this empty optional parameter is what is shown in frame header. Section name will still be used in table of contents. Similar solution can be adopted with \subsection commands.


text:
# Correctly setting chapter hierarchy [closed]

I'm not sure if I've phrased the title correctly, but let me try to explain:

I have my tex file basically organized as follows:

\frontmatter
...
...
\mainmatter
\input chap1
\input chap2
...

Each chapter input begins with \chapter{name}. Everything is nice in the Table of Contents as far as chapter numbers; yet, the "sidebar navigation" in the pdf displays incorrectly. The first two chapters after the first are shown nested in the first.

I've noticed I can resolve this by setting \setnumber{chapter}{1} before \input chap1, but this messes up the TOC to start chapter numbering at 2. This of course then leads me to try \setnumber{chapter}{0}, which then resolves the TOC, but messes up the navigation hierarchy. This bubble pops up somewhere else every time I push it down. Images of the two cases:

Min. working example:

\documentclass[11pt]{report}
\usepackage{
bookmark,
titlesec,
tabularx,
graphicx,
hyperref,
nameref,
amssymb,
amstext
}
\hypersetup{bookmarknumbered}
\setcounter{tocdepth}{4}
\setcounter{secnumdepth}{1}

\begin{document}

\maketitle
\tableofcontents
\listoftables
\listoffigures

\input 1-...
\input 2-...
\input 3-...
\input 4-...
\input 5-...
\input 6-...

\end{document}

I should note lastly, that the only difference between the first chapter and others is that it does not contain any sections. Noting this, I tried adding some sections. This did not change the problem.

Any help is appreciated!

I've updated the above to a new minimal working example. I've tossed the thesis template class as that was too hairy to try to debug. I noticed a duplicate equation label in the input 4, and removed it. I also added the bookmark package as suggested. One, some, or all of these changes fixed the issue.
• Unfortunately, the issue was present before using \setcounter{chapter}, and this was just my lack-of-knowledge attempt at fixing it. Removing \setcounter{chapter} reverts to the nested sidebar chapters in the first picture. – Chester Sep 11 '14 at 16:03
• I can't compile your MWE with sectsty package due to an error: Command \partfont already defined. ...{0}\SS@titlepart\SS@makeulinepartchap#1}} but without that package I cannot reproduce your problem. TOC works fine. My chapter include files contained just \chapter{abc} \lipsum and TOC numbering was correct. See if something in the include files messes up the TOC. Maybe post one of them stripped to the bare minimum? – ajeh Sep 11 '14 at 16:40
• It looks that either some of your \input files or your thesis template screws up the pdf bookmark levels. This is not solvable as neither the thesis template nor the content of the files input are known to us – user31729 Sep 11 '14 at 18:19