Tuesday, March 13, 2012

An Instantiation of a General Problem

(I wrote this, but never finished it, in China back around Christmastime. Randomly remembered it today, and thought this would be as good a place as any for it.)

The key was to be found across the city, in the old commercial district. We had tried simulations, implanted demos, viewed stereoscopic images through a haploscope we found in storage in the medical school. After all of these, we had tried hallucinogens to modulate the imagined presence of the key, but it was all to no avail. At least, we said to ourselves, when we finally approach the key we will be familiar with it. The front end of the process will not be a surprise.

The approach, however, to that front end, would be horrendous. First, our camp was protected from the feed. This kept the peace from finding us, but it also meant that our emergence into the feed would stand out like a tree in the desert. We had monitored the security cycles for days. Most would say that such monitoring was futile, since the cycle paths were random, generated with new seeds every minute give or take another random cycle. Any attempt, most would say, to predict gaps in the cycle would result in no better chance of unnoticed entry than no attempt at all, with the added hazard of false confidence to mask the creeping signs of detection.

It was possible, though, to closely estimate the number of cycles. We could detect the passes themselves, which gave us data for the estimation. The different cycles were unique, originating from different security servers, each assigned its own identification during its current generation. Given all these data, we had a method for estimating, at any given moment, the likelihood of a pass. The optimal estimate could be made using the previous twenty seconds of data. You could have pointed out that a likelihood is the opposite of a certainty, at least along a certain conceptual dimension. You could also have pointed out that the optimal estimate was lousy if those twenty seconds contained a generation update. We would have ignored you.

Once inside, we would have to obtain city ids from an admin, which was not trivial, but not a problem as long as we could quickly make contact with Tsai, our woman on the inside. We knew she was still online and that her admin was current, so as long as she wasn't in some unshakable stupor, she would tie us on and we'd be set for the rest of the trip. Anyways, persisting for a few minutes with unregistered cids wasn't as dangerous as suddenly emerging out of the void. An impulse is like that tree in the desert and the primary means of detecting aliens, while trouble finding a cid registration is a basic function of the feed servers, which would be checked in serial, assuming corruption or damage first and alien somewhere further down the line. Tsai could just tie us onto the oldest and most remote server, plot a false geographic history of intermittent reception and an outstanding service request, and there would be nothing in the feed to mark us out. The tree would dissolve into a puff of dust.

The next problem would be the actual emergence into the city. Feed presence can be smoothed over, anyone can appear to be anyone, fit into any group, assume any identity. The body, however, is much less convenient to modify. Their hair is long, but ours is short. Their skin is yellow, but ours is brown. We stand head and shoulders above them on the street, and we have no choice but to travel on the street for the most part, by foot, in the open, making stark and clear the comparison between foreigner and local. But, there are other foreigners in Haisheng. They are few and far between, but there are others, and though we draw attention it is natural, because who can ignore a brown spot among yellow? The noticing is in itself not a threat. But when others are looking for you, being easily noticed is a step away from being easily found. We did not want to be found, but there was no choice but to be noticed.

The final hazard was beyond any interaction with the first two. At the time I could not imagine how, but I was still cognizant that there was a possibility that the locked id had already been accessed by my competitors before I had retrieved it. If so, they may even have already decrypted it, outformed the important information inside, and restored the encryption. This was beyond any vital worry on my part, since the main danger was that knowing the key, and that I was looking to open the id, they might be waiting for me at the site. This meant I would have to move slowly through the streets, below them when possible, work quickly when it was time to get the key, and maintain vigilance on all channels at all times. There was nothing else we could do but be vigilant.

I can tell you more about the key without compromising the truth of the mission. Someday down the line, you may be able to put two and two together, but by that time whether or not you know such an obscure truth won't matter much, and you'll be occupied with obscuring your own. Anyways, it is an interesting detail, and may spark one or another interest in you.

The id I had retrieved was that of a neural engineer from a century or so earlier. We needed to query it regarding some interactions it had had at one time with our main objective, whose id at the time was missing and presumed destroyed. As it turns out this engineer had dabbled in id encryption, which was a new field in those days, specifically in encryption through perceptual experience. Though the field was active at the time, it was - and remains - completely unknown to the science that this particular engineer had worked on the problem. It was a private pastime, perhaps a paranoid fear that a great advance might be stolen, or maybe it was just a fear of inadequacy in an outsider bringing to the field such an idiosyncratic development. At any rate, this engineer had come up with something exquisite, which was probably unmatched by anything else produced by her generation. She may have meant it entirely for herself. Today, it's a work of art, but the tech is fundamentally outdated.

This is a digression, I'm sorry. Outdated or not, it was a good lock, and on site we still needed the key to open it. The encryption was applied to the id by taking the online state of some suite of perceptual systems, definitely including visual, possibly other - and by the way, don't take my ambiguity as indicating anything other than an intention to be ambiguous - and using this neural state as the key for the encrypted id. The entire state couldn't  be recorded, of course, since the subject would have to be standing out in the open at the location, i.e. a true state scan would be impractical, especially in those days. Instead, something was probably worn, perhaps obvious or perhaps hidden, instantaneously recording a blocked brain state amounting to just a few terabytes. It was a functional state, meaning that it could be reproduced in other human brains, but our initial estimate that a good visual simulation would suffice proved wrong. We needed to be there, unless someone could explain exactly what composed the key, and the only person who could tell us that, it appeared, was the one locked in that id.

Back to the problem. Being noticed, maybe being scooped, these were mostly outside our control. But skipping as an alien into a secure feed using random-cycle maintenance, that's something we can deal with. Look at the figure field. We used standard methods to monitor the cycles and establish their regeneration characteristics, how many there were, durations of the cycles, amplitude of the duration modulation - everything here is something you've seen before. You all have four minutes to generate the optimal estimate from these data, starting - now.

Monday, March 12, 2012

multi-channel M-scaled discrete filter convolution

Okay, so, I built this really neat discrete filter-based visual field model, planning to use it to measure binocular image statistics and to generate more realistic rivalry simulations. I hoped that doing the simulations would actually be quicker using the filters, since there would be far fewer filters than pixel images (I was using image-filter convolution to do the simulations I showed 2 posts ago), and the filters only needed to be represented by their scalar responses. Hoped but did not believe..

So now, I just spent the weekend (wrote that first paragraph a week ago) staring at the code, trying to figure out how to do, essentially, convolution of a function with an irregular array. It is complicated! I wrote a function to get local neighborhood vectors for each filter within its own channel, and then stared at that for a couple of days, and then realized that I should have written it to get the neighborhood without regard to channel. It's a pretty gangly operation, but it does have a good structural resemblance to stuff I've been thinking about for years. Ed and Bruce's relatively abstract idea about the broadband gain control pools, well, I've built it. Not for the intended purposes, since there's not going to be any gain control here - the only suppression that will be involved is like an 'exit gate', the permission for information in the channel array to be moved out to the later stages ("consciousness", we'll call it).

And, I say again, it's complicated. It's definitely not going to be faster than the rectangular filter convolution; in fact, it's likely to be 3 or 4 times slower, and it's going to produce rougher looking images on top of that. All this just to incorporate stupid M-scaling into these stupid rivalry waves. I swear, I can't think of a better way to do it. And the thing still isn't going to know anything about surfaces or faces or houses or any of that stuff, and it's going to take forever to debug and proof since it's going to be so slow...

But it's going to be cool.

Monday, March 05, 2012

retrograde inversion

Several times in your life you may hear it noted that the retinal image is reversed and upside-down. Fewer times than that, hopefully, you may then hear it noted with curiosity that the brain somehow undoes this retrograde inversion. When you do hear this, please interject with the following:

"The brain does not reverse the coordinates of the retinal image. The brain does not know or care about about the retinal image's orientation relative to the world; as far as the brain is concerned, the image is not upside-down, or upside-up, or flipped or double-flipped. It is not delivered to the brain with reversed coordinates, but with no coordinates at all. The brain assigns spatial coordinates to the visual information it obtains from the eyes. It does this by integrating information about body position, gravity, and other consistent sensory cues about the state of the world. There is no reversal or correction of coordinates, there is only assignment of coordinates."

You will promptly be thanked for clearing up the misunderstanding, and hopefully your interjection will serve to end one strain of a particularly irritating bit of pernicious nonsense.

Thank you.

Wednesday, February 22, 2012

Rivalry and Diplopia

A simulation of binocular rivalry and fusion with eye movements:

First, the input:

If you can cross-fuse, you want to fuse that white rectangle (and the matched noise background). It's hard to do, especially since there will be a strong urge to fuse the face, not the background. If you succeed, the girl's face will be diplopic (seen double). The video below is a simulation of what is happening in the parts of the visual field where the face is seen.

The photo of the girl is represented at two different ('disparate') locations for the two 'eyes' (just different filter streams in the simulation), while both eyes see the same background (noise with a little white block below the photos). At locations where the two eyes get different inputs (i.e. wherever the photo is seen), the two streams suppress one another and 'binocular rivalry' is induced. This rivalry is unstable, and results in periodic fluctuations where either one or the other eye's image is seen, but not both.

On the other hand, when both eyes get the same input, there is no suppression between streams (this isn't physiologically accurate, just convenient in this simulation). This results in 'fusion' of the two eyes images.

Every second, the filter streams - the eyes - shift to new, random coordinates (they are yoked together of course). You can see that by the shifts in position of the little black dot, which starts out near the white block.

(Both of these videos look a lot better if magnified, i.e. hit that little box in the lower-right corner and look at them full-screen.)

 

To make a little clearer what's happening, here's a color-coded version:

 
Here, locations where one eye's image gets through to be 'seen' are colored red or green (depending on which eye - geometrically it only makes sense that green-is-left and red-is-right, which would mean that the photo is between the viewer and the gray background), while regions where there is fusion are colored yellow or brown. The stream marker is now a blue dot (not really; the googlevideo encoder seems to favor dumping small blue dots against red/green backgrounds, go figure)!

Look at that mess of imbalanced fusion that builds up all over the scene. What a mess!

Wednesday, February 15, 2012

Process

Draft 1: Write 5000 words in 2 days.
Draft 2: Delete 1000 words, change 500 words, write 250 words in 2 days.
Draft 4: Delete 250 words, change 100 words, write 50 words in 2 days.
Draft 8: Delete 50 words, change 20 words, write 10 words in 2 days.
Draft 16: Delete 10 words, change 5 words, write 2 words in 2 days.
Draft 32: Delete 2 words, change 2 words, write 1 word in 2 days.
Draft 33: Delete 500 words, change 250 words, write 1000 words in 2 days.

Sunday, February 05, 2012

Two Dilemmas

The Train Dilemma:
If you run to catch a train which from a distance you saw pull into the station, it will depart just as you arrive. Next time, you will believe you can't catch it, and you will walk. If you walk to the station believing you can't catch the train, it will still depart just as you arrive. You will believe that if you had run you would have caught it, so next time, you will run. Ad infinitum.

Assume that all other things being equal, walking is preferable to running.

e.g.
run_speed >> walk_speed
distance / run_speed = "t_to_departure" + epsilon (very small interval), therefore just walk
distance / walk_speed = "t_to_departure" + epsilon, therefore run

The illusion here, or the problem in reasoning, is that the departure time of the train is somehow correlated with your decision to run or walk. If this is so, then the correct solution is to retain your dignity and walk coolly to the station every time. But it is unlikely that this is so.

Clearly the solution to this problem is to run every time, but it might take you a few failures to convince yourself of that. I've been in this situation many times on the way home from TKD, walking down the alley off Brookline that leads to Fenway Station; that's exactly where the D-Train comes out of the underground, and if when I get to the end of the alley I hear a distant screeching of metal wheels on metal rails, I know the train is coming, and I know I should start running.

The Bus Dilemma:
Let's say you have multiple paths to a destination, one of which includes a bus ride, but you don't know the schedule, only that the bus comes at a certain interval.

The dilemma here is whether or not to take your other option. Often, you might feel that you have committed enough time to waiting for the bus that you should abandon other options and just wait until the next one comes - otherwise, you've wasted all that time.

If the following propositions are true, then the dilemma occurs:
1. time_by_bus < time_by_other
2. time_by_bus + bus_period > time_by_other
3. bus_phase is unknown or undependable

If these are true, then it can be hard to decide just what to do. Keep waiting, or take the other route?

Again, the answer is probabilistic. If the bus phase is unknown, we can represent 'wait time' as a uniformly distributed random variable in the interval [0 bus_period]. We can then combine the after-weight travel times for the bus and the other route in the following way:

t_wasted = rand[0 bus_period] + t_bus - t_other

If t_wasted is positive, then the wait was too long and time would have been saved by taking the other route. If it's negative, then the wait was worth it, and time was saved by taking the bus. How do you use this to decide what to do? First off, look at what happens if t_bus and t_other are equal - in that case, t_wasted will always be positive, i.e. it makes no sense to wait at all, and you should take the other route every time.

At the very least, you want to break even on average. To do this, (t_bus - t_other) has to be equal to negative half the bus period, i.e. taking the other route should take as long as taking the bus plus half of the maximum wait time. Otherwise it's just not worth it, unless you get lucky. That's why those three propositions are necessary; otherwise you'll always know what to do.

After writing this out, I googled "bus dilemma", and what do you know: there's an arxiv paper on a similar problem. Here, he's considering whether to wait or walk along the same route (in which case you can also try to account for the chances you might have to catch the bus as you're walking), which wasn't how I was thinking of it, even though it's similar to the main example I had in mind. I was thinking about two situations: the bus stop in front of my old building in Louisville, where the bus came every 20 minutes or so, took 5 minutes to take you to campus, and was set against a 20 minute walk to campus. On average in this case, you would come out ahead, but I eventually decided waiting was boring, and the few minutes gained on average were better spent walking down 3rd Street.

The other example is of coming home from Davis Square in Cambridge, and deciding whether or not to catch the 86 bus home from Harvard Square or to take the D train home from Park Street. That one is more complicated since there are multiple waits involved, but since several times I've gotten lost looking for the 86 bus stop, the problem has run through my mind several times there...

Tuesday, January 31, 2012

Psychophysics and Consciousness

I reread this paper by David Chalmers yesterday morning for the first time in several years. I had been reminded of it because of this commentary by Kaspar Meyer in Science last week. The commentary was mildly interesting, and pointed out some of the current neuroscience perspectives as to just what consciousness is: e.g. is it the sensory experience with a background of knowledge and cognitive processes ("bottom up"), or is it a sort of best-estimate of what reality is given current and recent circumstances, using sensory input as a sort of reality check ("top down")? He finishes off in what seemed to me to be pretty fuzzy territory, but it was at least evocative of interesting ideas.

I'm vaguely familiar with some of this stuff, but I've never gotten too deep into because it doesn't satisfy me the way the philosophers do. The neuroscientists are looking for the "neural correlates of consciousness", which I guess is all that one really can look for. What this science reveals is the structure of consciousness, i.e. what is and is not included, what are the boundaries and how are they determined by the nature of the brain, and as indicated above, what exactly is the seeming 'core', or experiential reference point, of conscious experience, in neurobiological terms.

It is good stuff, but it always seems to me that the proposed theories far outstrip the basic science that is supposed to underpin them (e.g., in the commentary, Meyer cites experiments that demonstrate internally generated excitation of sensory cortex, and more generally recurrent activation, as evidence for the interesting idea that perceptual experience "would result from signals that descend through the sensory systems, just as behavior results from signals that descend along the motor pathways"). I don't know, that seems a bit of cart before horse, but like I said, I've only ever really skimmed the surface of this research. Meyer, Damasio, Dehaene, these guys are all basically frontal cortex cognitive neuroscientists, not perception scientists, and I've never really had cause to sink into that part of the science.

Now, the Chalmers paper. That's what I was going to go on about, not the Meyer commentary...

Anyways, in that paper Chalmers isn't really describing new ideas or new ways of thinking about consciousness (there is a subsection on some sort of "Kripkean" analysis of some philosophical point which I think actually subtracted from my comprehension of other parts of the paper, but it doesn't seem crucial). What he does is lay out a taxonomy of theories of consciousness - and the consciousness he's talking about isn't the "easy" kind, as he calls it, i.e. the NCC business that Dehaene is always going on about, but the "hard" kind, i.e. the fact-of-phenomenal-experience. I was thinking about that taxonomy yesterday evening, and wondering how psychophysics as a science fits into it, whether or not it biases one towards one or another way of thinking about phenomenal consciousness and just what it could be, or where it might come from.

As far as I know, the only visual psychophysicist who has written extensively (in English) on the philosophy of perception is Stanley Klein. I'm sure there are others, probably some I have heard of, but for now I'm guessing that if they exist they are writing in German or Italian. Klein is a proponent of the idea that phenomenal consciousness has something to do with quantum physics. Chalmers categorizes this sort of idea as dualist, since it supposes that consciousness is a quantum epiphenomenon of the activity of the physical brain. In other words, there is the brain and its physical structure, then there is a corresponding, consequent pattern or structure of quantum effects, and it is those effects that correspond to subjective, phenomenal consciousness.

I never liked this idea, at all. It usually relies on the Copenhagen interpretation of quantum mechanics to make the connection between observation and collapse of a wave function, which is the same thing that leads to that horrible Schrodinger's cat story. Not that I'm qualified to really have an opinion on this stuff, but that interpretation - that multiple possibilities exist simultaneously until selected by "observation" - is obviously nonsense, and just exists to show that something is not properly understood about the whole situation.

Okay, so I've shown myself to be a quantum mechanics ignoramus. Anyways, the QM-as-consciousness stuff is a type of dualism according to Chalmers, and I think it's quasi-mysticism, but does it have any currency among psychophysicists? I doubt it. I think Klein carries it because he was a student of Feynman who went into psychology, and he couldn't help but make the connection. He's an order of magnitude smarter than I am, maybe, but I think he's wrong.

As scientists, we might expect that psychophysicists should be materialists according to Chalmers' taxonomy. When I first got interested in perception and psychophysics was back when I was reading every bit of Daniel Dennett that I could find, and he is really the popular standard bearer of materialist theories of phenomenology (or was back in the 90's; this was the same time that I read Blackmore's "Meme Machine", and became completely obsessed with those ideas for a good couple of years). The idea here is that consciousness, in a way, doesn't actually exist; all that exists is the interconnected and multilayered and recurrent set of mechanisms for relating sensation to action over many timescales; in other words, "the mind is what the brain does". The fact that we have the impression of "looking out", or of being somehow spatially immersed in our thoughts and percepts, is a sort of necessary fiction that helps all those mechanisms to bind together and work correctly.

I'm not sure, but I think that J.J. Gibson might have been the closest thing (in the previous academic age) to a philosophical materialist in vision science. I suppose that most vision scientists adhere to a much more nuanced form of materialism, since Gibsonian materialism, or direct realism, is not really in good repute these days. I really like the idea in general, and consider it a good null hypothesis for study of perception - i.e. the perceptual world is the physical world that we tend naively to identify it with, and not a "representation" of the physical, and a given brain is a locus of limitations on what is known or remembered or simply accessible about this world.

Cognitive and perceptual neuroscience in general usually makes claims about consciousness that are consistent with the materialist position, i.e. that consciousness is the set of processes and functions of the brain. Chalmers says this (about neuroscience) explicitly. I always feel, though, (and I think that somewhere I've seen a talk by Dehaene where he says as much) that this is a terminological confusion, and that the neuroscientists must generally know, but forget sometimes, that the hard problem of consciousness, of phenomenology, is not addressed by their studies. Again, you know, I just have superficial acquaintance with this research, and maybe it's a common complaint amongst the Dehaenists that outsiders are always complaining that they (Dehaenists) are claiming that they're studying something that they aren't, when of course, duh, the Dehaenists know the difference. Oh well.

Finally, we wrap things up by mentioning what Chalmers calls monism, which is ultimately pan-psychism or pan-subjectivism. Reality has its relational, "objective" properties, and also its intrinsic, "subjective" properties. Phenomenal consciousness is simply the intrinsic nature of a functioning brain. This is an old idea, thousands of years old maybe, but it's not scientific. It's anti-scientific, even, since it's a claim that science, being the study of the objective nature of reality, can by definition not touch phenomenal consciousness. I think this is probably the truth of things, too, and it's kind of irritating. Anyways, is this a common feeling amongst psychophysicists, that the ultimate object of their study (whether or not they admit it; behaviorist materialism is a necessary stance for formulating good scientific theories of perception) is by definition un-attainable? That might be the answer right there; there's an operational stance (materialism), and a functional stance (monism), and only one of them - the wrong one - will ever get you anywhere.

I guess I'm going to have to start questioning psychophysicists. It will require a certain amount of drunkenness, I'm sure...

Wednesday, January 25, 2012

chinese american economics II

during this year's China trip, Jingping and I had a few discussions re the issue of $-元 exchange rate, and I noticed a few more points.

so, the Chinese state controls the international value of the RMB, for reasons including the cycle explained in that previous post. i didn't state there that there's a special factor making that cycle necessary, factor being that exchanges are only possible through government-controlled agencies (i.e. Chinese banks, which are all state-run). the Chinese state is slowly allowing the value of the RMB to appreciate, by a few percent a year over the past few years, because they recognize that the power of the Chinese economy has outstripped the exchange rate.

in other words, Chinese labor and land - i.e. export - is no longer as cheap and plentiful for foreigners as it used to be, and foreign labor and land - i.e. import - is no longer obviously prohibitively expensive. the Chinese don't want to damage their export system, and they don't want to get overwhelmed with a whole new system of imports, so they're making the RMB adjustment very, very slowly.

this isn't what I noticed, though. this trip, the topic of American investment kept coming up, especially in the context of wealthy Chinese sending their high school or college age children to study in the US. this must be barely affordable even for the upper-middle-class Chinese that are doing it, because private schools in the US are expensive even for Americans. the skewed exchange rate makes it even more expensive, probably by a factor of 2 or more.

on top of this, Jingping's parents gave us a good amount of money to use for her optometry school bills; this is money that they otherwise would have lent to people in China for a small return. they recognized that Jingping taking a large US loan ("financial aid") and paying a large amount of interest would be more costly than giving her the money and thereby giving up their Chinese interest. but, it's still a loss this way, because simply by moving the cash to the US and waiting any meaningful interval of time, the value of the money will decrease.

you can think about this more generally, and in bigger numbers. moderately wealthy Chinese, i.e. those just above Jingping's parents, have enough to invest in their child's education, accepting the exchange rate loss because, well, it's their child. but for the very wealthy - which in China often means state officials, investment abroad means business interests. wealthy Chinese own property abroad, have money in foreign accounts which they use to do international business. they do this because of the operational freedom it gives them, and because their profit margins must be larger than the decline in value of the foreign currencies (i.e. $$) they're using.

but if the drop were too fast... the foreign calculations wouldn't change, and business might actually pick up a bit if it had any connection to markets that were now becoming available to Chinese spending. but for the wealthy Chinese controlling those businesses, their domestic profits could drop precipitously. they might even lose money in the short term.

so, it's not just about protection of the Chinese export economy, or protection against foreign export economies; it's also about protection of domestic profits from profits on foreign investments.

Tuesday, January 24, 2012

Quote of the week, from a new PNAS paper (sorry for the Harvard link, but it's not like anyone actually will be clicking on that!) on using genetic manipulations to get silkworms to produce spider-like silk:

"Silkworms can be cultivated en masse, but territorialism and cannibalism preclude spider farming as a viable manufacturing approach."

Thursday, January 12, 2012

Priority Ranking

In another advance in procrastination, I have invented a method of ranking priorities of multiple projects. My primary reason for procrastination is still obscure, and we can just refer to it now by the shorthand term 'laziness'. However, I will maintain that important components of my procrastination include conflict between different projects, difficulty in efficiently organizing time, and inability to perceive in a useful or concrete way the relative priority of multiple alternative actions.

To address these three components, I decided simply to make a list of things which I have to work on, ranging from the immediate and obvious to the more wishful and distant. The list doesn't need to be deeply detailed, only superficially sketched, and it seems necessary that the different items should be mostly independent of one another. Having created this list, I then create a matrix of pairwise comparisons of priority of items in the list. The current list has twelve items, and so there are sixty-six comparisons to be made (twelve times twelve possible comparisons, minus the twelve identity comparisons, and then divided by two since order of comparison is assumed to be unimportant).

Each comparison is a rating on a three point scale. For each comparison, the following question is asked: "Given these two items (column, row), which is more important to work on right now?" If the first item has higher priority, the rating is 1.0; if the second item (i.e. not the first item), the rating is 0.0; if priority appears equivalent, the rating is 0.5. Below I've pasted in the current matrix. Only the values below the main diagonal are filled in; the main diagonal is null since these are meaningless comparisons, and the values above the main diagonal are automatically filled in as the inverse of the corresponding comparison below. Total priority for an item is simply the average over all rows for each column, and is shown in the leftmost column.


I think this system has potential! We'll see if it helps, and if I can keep up with it, updating it regularly. I haven't made up a scheme for what to do with projects that pass some sort of milestone; if a paper is finished (does that happen?), the item would probably just be removed from the list, while projects would transition to papers. There, I just made up a scheme!

Here's to organization!

Wednesday, January 11, 2012

design change

Look at the new design! I'm so excited. I'm going to post every day now, really.

We also have a new url, xuexixiangshang. This is the only configuration of 好好学习,天天向上 that worked as a valid prefix for blogger.com. It's a great slogan, and not quite as embarrassing as everyoneisdead, which belies that I didn't really expect this journal to last so long. Downside of changing the url is that my MS-WBT traffic is going to halt, though I guess eventually it will probably pick up again. Whatever!

Monday, January 09, 2012

Wuhu Environs


About five hundred kilometers upstream from the Pacific, the River runs east and then abruptly north. Sprawling eastward from the northern arm of this right angle is the City of Wuhu. The main body of the City is pressed up against the River, which is still the region's main artery for trade, though in turns railroads and now highways have added new arteries, enabling the City to sprawl away from the River in new directions, and to mix its influence with its neighbors.

To the south, the City begins to wrap around the River bend before it fades into farming villages and the occasional satellite towns that sit between and around the tips of the northernmost foothills of the Yellow Mountains. My wife was born in one of these towns, and her parents in another smaller one nearby, the two towns separated by a long fragment of those foothills, a little mountain with a northward spine. Her ancestors are buried on the slopes of that mountain.

Eastwards, there are marshes which have been engineered over centuries, or millennia, into networks of polders, surrounded by channels filled with water from distant rivers, on each of which sits a tiny village or a cluster of tended fields, or both. Some of these networks are regular, laid out in vast grids tens of kilometers across, showing from any vantage point the mark of some overarching plan, carried out long ago by the people of those marshes. Others follow no obvious pattern, except that there seems to be some average island size, similar to that constant size of the regular networks, and some acceptable deviation from this average, and an agreement amongst the people that they were going to reform the marshes into channels and islands.

Surrounded and out of options, the Hegemon Xiang Yu is said to have killed himself nearby, two-thousand two-hundred and fourteen years ago, and someone is supposed to have taken his horse's saddle up onto a mountain and buried it. That mountain gives its name to the City of Ma'anshan, which also presses up against the east bank of the River, fifty kilometers or so north of Wuhu. This City is known for making steel, and a ride through town will show you infinite smokestacks and gray air that covers everything, it is beautiful and terrible all at once.

Further north along the course of the River is the Southern Capital, and from there the River makes its final drive east where it breaks apart and becomes Shanghai. Across the River bend from Wuhu, north and west, is Chaohu, which has recently been dismembered by its neighboring Cities, most notably the provincial capital of Hefei, which sits even further along the same northwest vector.

Westwards, up the River, there is more, Hubei and Jiangxi and beyond, but there is more in every direction, and the mind follows the flow of the river back towards the Ocean in the east, and does not easily run against it, and these are enough reasons now to conclude and say that the City rules the neighborhood of that bend in the River.

Wednesday, December 07, 2011

MIT VPN

Just when I've lost interest in the internet, I get the following random email on my Gmail account (found it in the Junk folder):

Dear Outlook client, Notification ID: KG932J ========================================== - Please reconfigure your Microsoft Outlook information again . - Click on the link below to setup . http://outlook-mail-setup.gert54d.from-ks.com/index.php?id=KG932J ========================================== Microsoft Outlook 2012 .

Obviously this is a phishing thing. What's interesting is that the url refers to an IP address at MIT. The address is no longer active as far as I can tell, but it seems to have belonged to the MIT VPN network, because other addresses on the same /24 block are attached to vpn-ip.mit.edu urls.

So, my guess is that someone set up a site on the MIT VPN to direct their phishing business. That's all I've got.

Oh, coincidentally, just yesterday I was reading about VPNs, wondering about a convenient way to get past the China firewall from the inside. Seeing that MIT has a VPN makes me wonder if Harvard has one, and if I can use it...

Thursday, November 10, 2011

Typical Monday through Friday

In the morning, at eight o’ clock, two alarms go off. The clock is next to his bed, and he reaches over to stop it, sometimes temporarily, sometimes permanently. The radio is in the hallway, just outside the bedroom door, and he comprehends it to varying degrees.

Sometimes his wife is up before him, but usually not. He gets out of bed, finally, usually before nine. He makes coffee and takes a shower. He brushes his teeth and gets dressed. He packs his lunch and makes a peanut butter sandwich for breakfast. He fills a coffee cup and a thermos with coffee, adding enough milk to make it cool enough to drink quickly. He sits by the front door and listens to the radio news, eats his sandwich, and drinks the cup of coffee. If his wife is up, maybe they talk, or maybe she’s in the shower.

If he’s planning to go to tae kwon do that night, he takes his uniform, which is hanging from the radiator in the bedroom, folds it, puts it in a plastic sack, and packs it in his backpack. He gets ready to leave, puts on his shoes, speaks with his wife, kisses her, and goes out the door. If it’s raining, he takes an umbrella. If she’s up, she locks the door behind him, otherwise he takes his keys and locks it.

He steps outside and picks up the newspaper. He stops by the wall in front of his building, sets the thermos down, and puts most of the newspaper in his backpack, except for the front page. He sets off for Reservoir.

Walking down Sutherland Road on the right side, he may encounter some other people, but usually there are few, because most have already gone. He passes several other apartment buildings on his way. Often, there are workmen at one building or another, unloading things from their truck. Maybe he can hear them speaking Spanish to one another.

When he arrives at Cleveland Circle, he’ll try to walk straight through. Half the time, it’s not hard to do, since half the time the traffic is running across Beacon Street. Even if Beacon has the light, they might all have gone. Sometimes he stands and waits. This crossing is a convergence point from several directions, and more people seem to arrive from along Chestnut Hill than from Sutherland. Sometimes he sees someone interesting here, and can watch them until they all arrive at Reservoir.

At the other side of the Circle is Reservoir, but before he gets there he passes his dentists office. He owes the dentist money. He thinks he might have a toothache, but he’s not sure. He wonders if you can give yourself a toothache by focusing all your attention, and the tip of your tongue, on one healthy tooth. His mouth tastes like metal sometimes, since he got all those fillings last summer.

He arrives at Reservoir. It’s random. Sometimes he’s just in time; sometimes he’s just missed it; sometimes he waits. If he waits, he watches the people accumulate. Most of them he doesn’t recognize, but some he does. The people trickle in, then arrive in a wave when one of the buses arrive upstairs, then more trickle in, then the train arrives. He always tries to get on first, on the very back door. Usually he manages to be one of the first.

Unless he’s really late, there’s probably not a seat. He stands or sits, finishes his coffee, reads the front page of the Wall Street Journal, and people crowd on the train. More get on at Beaconsfield. He stares at people when he thinks they aren't noticing, but he assumes everyone else is doing the same thing. He compares nose shapes between two people. He tries to find two noses that are most different, and two that are most similar. He looks for noses that look like his. He is ceaselessly amazed by the irrational variance of noses.

More get on at Brooklines Hills and Village, but some get off there too. At Longwood, half the train gets off. Postdocs, doctors, students. Most of them are Asians.

Station by station, he gets closer to Government Center. Sometimes they make everybody get off at Park, and get on the next train. At Government Center, he always tries to be the first person off the train, out the back door. He can usually do it. By the time the train gets to Government Center, which is the last stop for the D train, there aren’t usually many people still on board.

If the escalator is open, he walks up and out of the station. If someone is standing on it, he curses under his breath and runs up the stairs. It’s a narrow escalator, no room to pass someone who’s just standing there. If someone is just standing there, they might clearly be a tourist and he forgives them. If they're looking at their phone, he sneers. He wonders why the others all line up to stand quietly behind, when he knows they all really want to climb.

Outside is Government Center, City Hall, the Federal Building. The plaza is bleak and impressive, every day. He walks down Cambridge Street towards Mass General. To cross Staniford, to get into the Institute, he usually dodges through traffic stopped at the light. He enters the Institute through the front door now, since his office moved to the other side of the building, and the receptionist always tries to talk to him about the weather. He doesn’t slow down, though.

He goes up the stairs to the second floor, down the hallway by the human resources offices, past the elevator and the second floor wetlabs, past the conference room, across the bridge to 2West, takes a right down the hall by the driving simulator, past the little kitchen where he microwaves his lunch every day, past the meeting room, past the restrooms, take a left, through the research assistant office, says good morning to Jackie at her desk, steps into his office, sets his backpack on his desk, hangs his jacket on his chair, sits down, and wakes his computer.

Andrew has gone to work.

Wednesday, October 19, 2011

not writing

He couldn’t think of how to start.

He couldn’t even start! If you can’t start, how can you continue? How can you then finish? Starting is fundamental. It’s the first thing. Starting comes before everything else. He decided that instead of starting, he’d circle around, try to sneak up on it. The frontal approach wasn’t working, but maybe there was a soft spot somewhere in the back. I’ll circle around, he thought.

He started to write about not knowing what to write about. In its own way, it was working. Letters were coming out. The letters came out through his fingers, pooled into words on the page, the words clumping into phrases and sentences. Was this the right way? The flanking maneuver continued, but the result had not yet been achieved. This isn’t what I want to write, he thought. I want to write something else. It’s up ahead now. Right up ahead.

Or is it? Have I gotten lost on the way? In avoiding the actual confrontation with the thing to be written, he had tried to creep around, to surprise the thing, to tackle it from an unsteady angle. But how long should the creep take? Should it go on and on like this? When should it stop? When has it failed? When has it almost succeeded?

His mind wandered, dragging with it the stream of letters and words and phrases and sentences. He thought about waiting for a bus when you’re going a distance that you could reasonably walk. A twenty minute walk or a three minute bus ride, that’s usually the choice. The problem is when you don’t know if you’ve just missed the bus, or if it’s about to come up over the horizon at any minute. The more time that goes by, the more likely it is that you have just missed it, and that it really might be another good long while before it shows up.

That’s what the flanking maneuver was like, but not really. Because really, a flanking maneuver fails in one of two ways. One, you get lost, or you arrive at position too late, and the enemy is just gone, and you have to start over again, and by the time you find them again you’re likely to be face-to-face, just like when you started. Two, the enemy might notice what you’re doing, and you arrive exactly where and when you intended, but they’re ready for you, and it’s face-to-face again. The first is worse, because then you have time to be demoralized and disappointed. The second is better, because when you arrive you’re ready to fight anyways, even though now the situation is maybe not exactly what you had planned.

It would be best if they didn’t know you were coming. If the thing to be written could just suddenly find itself being written, without knowing that it was being written, that would be ideal. But how realistic is that? The flanking maneuver was never a good idea. It could never work in this situation. No matter what, you wind up at the same point, with the thing to be written, waiting to be written, not being written.

Friday, September 09, 2011

memory

So, my office moved to the other side of the building a month or two ago. My lab is still over there near my old office, and that's also where the copier room is, and the kitchen where I get hot water to drink. So, I do still go over there frequently.

One thing I don't do over there so frequently is use the bathroom - there are two restrooms near the new office, so now I usually go there. These two restrooms are both unisex, and are next door to eachother, and are basically mirror images in layout. The old restroom is laid out differently.

So, just a few minutes ago, I go to the kitchen to get some water, set my mug on the coffee maker to wait for me, and go into the old restroom. This whole time, I'm thinking about the talk that Shrinivas gave a little while before. I do my quick business in the restroom, turn around to leave - and realize that something is wrong. I don't recognize my surroundings. I don't know where I am.

At first, it was kind of terrifying - I thought that I didn't know where I was at all, but quickly realized that, really, I just didn't know which bathroom I was in. The lighting, i.e. the color temperature, was unfamiliar. The layout seemed wrong. "Which one am I in?" I thought. "The left one or the right one?"

I stood there for a few seconds, and thought hard about what was wrong, then finally figured it out. I remembered the water, and that I must be in the old restroom.

That makes two times now that I was in that restroom and thought I was having a stroke. First time was the first time I had experienced a visual migraine aura, which was much more awesome than this.

Thursday, September 01, 2011

1k/mo

Got over 1000 page views for the month of august, basically because last week was HUGE for my classic comedic dialogues and self-indulgent essays. No no no, really, it was MS-WBT server. Observe:
Yeah, I don't know what's going on. Whatever it is that causes people to google "MS-WBT server", and wind up here for a few seconds, got a little worse last week - visits increased by something like 30%. Google is weird, the internet is weird, MS-WBT server is weird.

Going to Nashville tonight!

Wednesday, August 31, 2011

self

I have been thinking frequently about who I am, and about whether who I am has changed over the years, and if so, how.

One thing I keep returning to is this feeling that I am losing myself, or that my self is somehow diminishing over time. What I mean is, I feel more and more that I am what I do, and what I see and feel, and the people I interact with - mainly Jingping (not that I think I am Jingping, no) - and the random thoughts that run through my mind when I'm away from things to do or people to interact with.

This isn't necessarily a problem. I don't mind being my thoughts, or being an interaction with my wife, or being the work that I do, or the procrastination that I put between myself and my work. These things, or parallel things, are what I think we all are. But parceling your self into these discrete components makes them identifiable, and subject to direct analysis, which can reveal things in stark detail that you realize you just don't like. There are some specific features that bother me.

When I was younger, I spent a large portion of my free time writing. I wrote stories, essays on my thinking, letters, etc. I did this because I wanted to. Now, I write because I have to - I do research, and I have to write about it to sustain my personal profession. There is always work to do, and when I feel willing to write, I feel I have to apply this will to work, not fun. So, I almost never write for fun anymore. Even worse, I realize that I distract myself from this sort of unease by reading what others have written. It's as though I'm replacing parts of myself with parts of other people.

Also, over the years, I more and more began to think of my self expression as excessive, or pretentious, or useless, and so I suppressed it. I think that my entire character is suppressed. This has not had the result of simply bottling up my character, but instead I think that in some ways I am withering away - I feel that even if I tried to go back to my old ways, of writing out my thoughts regularly, there would be less to write. This is why I am writing this entry, which even as I write it feels excessive, pretentious, and useless. I feel like I have to get a ball rolling, though.

Another thing that bothers me is what I think about. We all have recurring thoughts that irritate us, things that we don't want to think about but that we do anyways. Some of these things are fine at a high level, because they are features of our lives. But other things - news, politics, etc., I find myself repeatedly going through these internal monologues, not daily but frequently, on topics like the American military, US history, religion, politics. Why? I tell myself that I don't care about these things, or I try not to care - I have no effect on them, and they seem to have no effect on me. I feel infected. I want to think about my life, my wife, my work, about things I enjoy. I'm not a politician or a columnist - why do I obsess over these sorts of things? I have not figured this out. I do get a strong feeling that these sorts of thoughts erode my self - they are not me, they are other people, other places. They make me forget who I am.

I am not bothered by thinking about sex or violence, or obsessing about the aesthetics of the Green Line tunnels, or wanting to see if someone sent me an email or a Facebook message, or my shabby piano playing. These are aspects of my life, they are fine in themselves - some of these things may specifically implicate odd aspects of my personality, but so what?

Conclusions: I still exist, but I have doubts about the vitality of my existence. I have suppressed myself too much, and the empty spaces in my mind are more and more taken up with irrelevant puzzles. I'm thinking that a solution may be to do something like this regularly, do more writing for fun, try to be more expressive with other people, stop always trying to hide myself from the outside.

Friday, August 26, 2011

hypothetical question

Okay, so let's say you run the following experiment:

You want to compare different states of adaptation. The yardstick you're going to use to compare them is is a matching function. You have two stimuli, x and y, and you're going to assume that the associated matching function - your matching function model - is simple, like y = mx + b. You want to know how those function parameters, m and b, vary when the adaptation state changes.

To do the experiment, you keep one adaptation state constant in all conditions. You can do this because you have two stimuli, and you can adapt them separately. So, you have two adaptors, X and Y. You keep adaptor X the same in all conditions, but you vary adaptor Y. Since X doesn't change, you can then compare the effects of Y across conditions. Adaptor X is your baseline.

Within a subject, this design is fine. You can take your xy data from different X conditions and plot them on the same axes. You look at how the data for X1 differs from X2, for example. You fit your model to the X1 and X2 data, and find that mX1 is higher than mX2. You repeat the experiment with another subject and find the same pattern - the m values are different across subjects, but you see the same relative difference between mX1 and mX2 for every subject you test. You average the results together to show that mX1 is higher than mX2. This constitutes a result of your study.

But then...

You start to look at the individual data, at how the m values vary so much across individual subjects, but that within-subject difference is always there. You think, something is covarying between these two things, what could it be? Why is it that whatever value mX2 takes for a particular subject, mX1 is always higher?

Then you realize: Y. mX1 and mX2 might not vary at all, at least not to the extent that they appear to. Maybe its mY that's varying.

Look at that model from the point of view of Y. Then you have x = (mY)y + (bY). Turn it around, and you get y = (1/(mY))x + (bY)/(mY). This means that mX is inversely proportional to mY, so that measured values of mX1 and mX2 will be similarly affected by differences, across individual subjects, in the value of mY.

Well, this led somewhere, anyways.

Saturday, August 06, 2011

zipper trucks

Yesterday I learned about the existence of zipper machines. We were driving back from Foxboro and there were all these little movable barriers on the interstate; I might have said something about them, and Matt explained that they were moved every day by big, slow-moving machines. I couldn't believe it, but you could see that the barriers were all linked together with springed, metal joints. I came home and looked it up, and found that link, and some youtube videos. I have to see one of these things in action...

Also, my poem output was way up over the last few weeks (like, above zero per week). They're all in drains like google or weekly report or facebook, so for posterity let's put them here. For my birthday, I made a haiku:
thirty-two years down
won't pick up another bit
for as many more

I thought that was clever.

Then, Murf decided to institute a Thursday google+ rhyme circle. Murf started with:
"i'm a serial gangsta, so don't you be hatin';
these rhymes are coming at you - 9600 baud ratin'.
i'm a cereal gangsta, pouring as smooth as silk
all o'er these fruity pebbles some quality soy milk."

I responded with:
"
why's your baud so slow, must be messin' with your flow
don't hate, i got infinite bit rate,
symbols at the speed of light
like nuclear fission, constant information transmission,
a meltdown, crossin' synapses,
no lapses, my latency's good, it's understood 'cause i drink real milk
fortified, omega-3,
carbon chain, developin' my brain, got to sustain that spike train"

I was proud of that. Then one night this week I generated this for facebook:
"
no frogs,
no crickets,
 
no bugs at all. 
just air conditioners, 
and echoes of air conditioners. 
no, wait, 
i hear something- 
i hear a bug. 
what is it? 
what is it?"

That was kind of lame, but it was accurate. Then yesterday the Thursday rhyme circle was late. Murf began:
"
Subjective speckle, what do you say?
650nm class IIIA
Black spots moving as I'm delighted;
Not in my same direction means I'm near-sighted."

And I responded with this:
"
myopia, that's some shit
some negative lenses would fix it
stimulatin' those long wavelength cones
seein' red, thinkin' about homophones
"

I am such a genius.