最近在几种自媒体节目中频繁听到“心流”一词，遂查之。追根溯源，有CSIKSZENTMIHALYI 的著作《FINDING FLOW》。此书1997年已出。 原来 心流不是一个新概念，就像作者所说，先贤圣哲早已讨论过，因为 追求快乐 是每个人的诉求。 1. 什么是心流 。 它是一种专注过程以及随之来的快乐感受。 快乐是情绪，我们都是 情绪的奴隶 ，即便如此也要设法追求快乐。佛说诸漏皆苦，出世的方法似乎在现代社会不凑效。与先贤不同是，作者用科学的方法去访问、抽样、ESM等相对客观的手段研究快乐，得出结论如图。 2.心流在哪？心流条件? 心流可以发生在任何场景中，工作生活家庭娱乐等。有人在一圈圈 跑步中获得心流，如村上春树，也不妨碍有人在一 麻将中感受心流，但如果作用于自我提升则就两全其美了，比如李太白醉酒能写诗。 心流产生的条件:拿厨师举例，据研究其实男人更喜欢做饭。因为，有目标，掌控性，创造力，专注，及时反馈。加上能力和难度正好在中间位置。 3.工作好还是休闲好？ 每个人都想少工作多休闲，但作者研究虽然工作中有诸多负面情绪，但是获得心流频率远比被动休闲如看电视等高。 4.如何分辨信息。 读此书，想起一直以来的问题，怎么在海量信息中提高辨别力。机器知道你的算法，不断给你推送你想看的，就像红楼梦里风月宝鉴，人性难以抵抗。也许提高心流能力是一种办法。 5.家庭，男人女人。 几乎没有一个不争吵的家庭，否则完美的不太真实，但是我们可以通过了解男女思维在家庭中获得快乐，男女双方同时拥有男女思维更好。比如， 6.男人想要的女人 女人想要什么男人我不清楚，第一我不是女人，第二根据进化心理学，女人的防御机制非常复杂以致于女人也不知道自己要什么。男人要什么，根据自身体验，自身体验算不上客观，但也可从经验上归纳群体理论。简单来说，男人要“又男又女”的人，这样的人同时拥有感性与知性，肉体与灵魂。如果女人不同时具备感性和理性，多数男人愿意只要感性，只要外表，少数男人只要理性，如诸葛孔明。极少数不一般的男人找另外一个男人。 7.命运还是命运？ 作者最后一章loveoffate，拥抱命运，命运主观性太强，似乎作者陷入了不可知和宿命论，但是我喜欢（其实作者是讲要自足）。就像这篇读后感，本来懒得动手，突然强烈的表达(嘚瑟)欲望涌现，不吃不喝写读后感。此即心流？俺快乐？ 看到这2个名言，“ 自足 ”也可能在他人眼中不值一提。 1. The unexamined life is not worth living----Socrates. 2. It is better to be a human being dissatisfied than a pig satisfied; better to be Socrates dissatisfied than a fool satisfied.---J. S. Mill
论文的“Flow” 有一次，一个审稿人，对一篇投稿的论文提出，论文某一处的“flow”不好。当时，还不太明白，后来懂了，是论文的逻辑和行文不够流畅，给人卡顿的感觉。 再后来，也逐渐感到，一篇文章写得好不好，其实就是文章呈现的“flow”好不好。我们经常读到好的论文，有知识，又有品味，行文如流水，娓娓道来，读后酣畅，这就是好的文章。 但当自己真正开始写作时，经常感觉写不好，甚至写不下去，要么文字如蜡之堆砌，生硬枯燥，疙疙瘩瘩；要么言之无物，重复老套，缺乏新意。总之，缺乏一种流畅淋漓的感觉，就是“flow“的感觉。 写出一篇好的论文，其实也不是那么容易，除了需要潜心研究，深晓其理，洞察一切，入木三分，化繁从简，也许还需要那么一点久久用功后的豁然开朗、欣喜若狂后的口吐新言，也许就是创造了一点点新的“flow”。如果一篇论文，经常出现如此“flow”，即使不能算是“好文”，也算是“新文”了。总之，如果能够在写作论文中有更多的“flow”，至少你的心也暂时性享受了更多的“flow”了。 那么什么是文章的“flow”呢？ 粘一个帖子吧，尽管是关于一般散文文章的，但还是可以供大家交流、借鉴一下。 What Writers Mean by “Flow” By: admin | June 1, 2011 27 THE F WORD We all have our pet peeves. One of mine is the word flow . In my three decades as a creative writing teacher, I’ve heard it literally thousands of times. It’s a rare class in which I don’t hear “It flows” or “It doesn’t flow” offered as an explanation of what’s good or bad about a story we’re discussing. What bothers me about the word—beyond the fact that I hear it so often—is that my students generally don’t seem to understand what they mean by it. They intuitively recognize flowing prose when they read it, but they’re not sure what constitutes it. If I ask them what makes a particular sentence or story “flow,” they’ll answer with semi-synonyms that are equally vague: “It’s the rhythm,” they’ll say, or “the pace,” “the style.” They can’t really define it. I’m afraid I can’t either, at least not adequately. My response to flow is undoubtedly as intuitive as theirs, for when we talk about flow we’re talking about an element of writing that is more music than meaning and thus beyond rational explanation—perhaps even beyond language itself. Hence it’s extremely difficult to discuss, much less define or teach. Difficult, but not impossible. While there is much about the flow of prose that will inevitably remain instinctual, there are some aspects of it that can be discussed, understood, and even practiced. The principal purpose of this essay is to try to make our unconscious understanding of flow conscious, so that those of us who don’t instinctively write flowing prose can practice the skills and strategies involved until they become so habitual they are, for all practical purposes, instinctive. Let’s begin by looking at a paragraph that—my students and I agree—flows extremely well. It’s the opening paragraph of a story submitted to Ford Madox Ford in 1909, when he was editor of the English Review . According to Ford, the story was sent to him by a schoolteacher from Nottingham who informed him that it had been written by a young, unpublished author who was “too shy to send his work to editors.” Ford didn’t expect the story to amount to much, of course, but the moment he finished reading the first paragraph, he laid the story in the basket reserved for accepted manuscripts and announced to his secretary that he had discovered a literary genius—indeed, “a big one.” And that night, he told his dinner companion H.G. Wells the same thing, and Wells passed the word on to people seated at a nearby table. Before the night was out, two publishers had asked Ford for first refusal rights to the young author’s first book. All of this happened before the author even knew his work had been submitted to an editor, and it all resulted from a single paragraph. What was it about this paragraph that impressed Ford so much that, without reading a single word further, he accepted the story and judged its unknown author a genius? In his explanation of his decision he points out many of the paragraph’s virtues, but he stresses two in particular that convinced him he could trust the author “for the rest” of the story: The author employs “the right cadence,” Ford says, and “He knows how to construct a paragraph.” In my opinion, cadence and paragraph construction are two of the principal things we talk about when we talk about flow. If I’m right, the paragraph’s flow is a major reason—perhaps even the principal reason—Ford recognized genius in it. Lest this turn into an essay on how to create suspense, let me say now that the then-unknown author of this paragraph is D.H. Lawrence and that it is the opening of “Odour of Chrysanthemums,” his first published story. Here’s the paragraph: The small locomotive engine, Number 4, came clanking, stumbling down from Selston with seven full wagons. It appeared round the corner with loud threats of speed, but the colt that it startled from among the gorse, which still flickered indistinctly in the raw afternoon, out-distanced it at a canter. A woman, walking up the railway line to Underwood, drew back into the hedge, held her basket aside, and watched the footplate of the engine advancing. The trucks thumped heavily past, one by one, with slow inevitable movement, as she stood insignificantly trapped between the jolting black wagons and the hedge; then they curved away towards the coppice where the withered oak leaves dropped noiselessly, while the birds, pulling at the scarlet hips beside the track, made off into the dusk that had already crept into the spinney. In the open, the smoke from the engine sank and cleaved to the rough grass. The fields were dreary and forsaken, and in the marshy strip that led to the whimsey, a reedy pit-pond, the fowls had already abandoned their run among the alders, to roost in the tarred fowl-house. The pit-bank loomed up beyond the pond, flames like red sores licking its ashy sides, in the afternoon’s stagnant light. Just beyond rose the tapering chimneys and the clumsy black headstocks of Brinsley Colliery. The two wheels were spinning fast up against the sky, and the winding engine rapped out its little spasms. The miners were being turned up. When I show this paragraph to my students, they invariably praise its flow. Even those who complain that the prose is too “descriptive” or “old-fashioned” (words that many students consider synonymous these days, alas) find the flow of this overly descriptive, old-fashioned prose to their liking. When I press them for an explanation of what makes the passage flow, however, I rarely get more than the verbal equivalent of shrugged shoulders. To help clarify for them, and me, what makes Lawrence’s paragraph flow, I offer them a revision that, we all agree, does not flow. I won’t subject you to the entire revision; my point should be painfully obvious after you see how I’ve butchered Lawrence’s first two sentences. The small locomotive engine came down from Selston. It was Number 4. It clanked and stumbled. It had seven full wagons. It appeared round the corner. It made loud threats of speed. It startled a colt from among the gorse. The gorse still flickered indistinctly in the raw afternoon. The colt out-distanced the train at a canter. Awful, isn’t it? But why? My sentences contain the same content as Lawrence’s, and that content is presented in essentially the same order, yet the passage is as stagnant as the afternoon light Lawrence describes. So clearly neither content nor order determines flow. (For further evidence, take a look at Raymond Queneau’s Exercises in Style , in which he tells the same brief incident ninety-nine times, keeping its content and order intact and changing only the style and, therefore, the flow.) Nor does ease of reading determine flow, since the revision is significantly easier to read than the original—even a grade-schooler could follow it. So what is the essential difference between the two versions? Nothing more, or less, than variety of sentence structure. That sentence structure is related to flow is an obvious point, no doubt, but if there’s one thing I’ve learned as a writer and a teacher, it’s that when something is obvious, we tend not to pay it sufficient attention. So let’s pay closer attention to the relationship of sentence structure and flow in Lawrence’s paragraph. There are, of course, four basic types of sentence structure—simple, compound, complex, and compound-complex. But within these four general categories, there are many different types of structure, as the grammarian Virginia Tufte has demonstrated so superbly. In her book Grammar as Style , Tufte defines—and illustrates—innumerable ways to structure sentences, using left-, mid-, and right-branching modifiers, balance, repetition, coordination, inversion, apposition, and a vast array of other techniques. Significantly, Lawrence uses all four sentence types in his paragraph, not to mention many of the structural techniques Tufte describes. More importantly, seven of his ten sentences are either complex or compound-complex, the two types that permit most variation in structure. For example, both the fourth and seventh sentences are complex, but one contains five dependent clauses and the other only one. Because of the variety of sentence structure in the paragraph, Lawrence’s sentences range from 6 to 62 words. I use only the simple sentence pattern in my revision, however, and so my sentences range—if they can be said to “range” at all—from 4 to 9 words. According to Tufte, “The better the writer, … the more he tends to vary his sentence length. And he does it as dramatically as possible.” Since variation of sentence length results from varying sentence structure, ultimately it’s our syntax that determines whether our prose flows or not. As Stephen Dobyns tells us, syntax is like a landscape: If it’s too uniform, as in my revision, our prose will look more like Nebraska than Switzerland. A variety of sentence structure—and therefore of sentence length—will give our prose a more flowing, and appealing, landscape. But because we don’t think enough about syntax when we read, we don’t think enough about it when we write, either. As a result, our work—my own, as well as my students’—tends to rely far too heavily on the two most basic sentence structures, the simple and compound. There’s nothing inherently wrong with either, of course. In fact, the simple sentence is the base structure, the ground note of all prose. We can’t, and shouldn’t, do without it. But it is also the structure with the least possibility for variation in syntax and length since there are no other clauses, dependent or independent, attached to its single independent clause. The compound sentence structure is only slightly more complicated since it merely connects simple sentences with a conjunction. Because these two sentence types so dominate our writing, they prevent our prose from achieving that flowing cadence that marks the best fiction. As Robie Macauley and George Lanning have said, the simple, minimalist style “has its Spartan virtues but it also has its Spartan vices.” And chief among those vices is a lack of flow. Why are the simple and compound sentence types so dominant in our prose today? I asked my students and colleagues this question, and virtually everyone gave me the same answer: It all goes back, they confidently asserted, to the influence of Hemingway. But I disagree: Hemingway’s simplicity is far more a matter of diction than of syntax. Like Lawrence, Hemingway knew how to vary sentence structure so his paragraphs flow. If you look at random paragraphs from his work, you’ll notice how the simplicity of his diction exists within the context of complex syntax. The opening paragraph of “A Clean, Well-Lighted Place” is a good example. It was late and every one had left the café except an old man who sat in the shadow the leaves of the tree made against the electric light. In the daytime the street was dusty, but at night the dew settled the dust and the old man liked to sit late because he was deaf and now at night it was quiet and he felt the difference. The two waiters inside the café knew that the old man was a little drunk, and while he was a good client they knew that if he became too drunk he would leave without paying, so they kept watch on him. The prose here is admirably straightforward and clear, but its syntax is by no means simple. All three of these sentences are compound-complex, and no two share the same structure. The number and placement of dependent and independent clauses in each varies significantly; the sentences have two, five, and three independent clauses, respectively, and one, four, and three dependent clauses. And the placement of the dependent clauses varies widely, too: The one in the first sentence follows an independent clause whereas three of the four in the second sentence precede independent clauses. And in the third sentence, two dependent clauses are embedded in the middle of independent clauses. Flaubert once said that “The sentences in a book must quiver like the leaves in a forest, all dissimilar in their similarity,” and these sentences do exactly that. I don’t believe for a millisecond that Hemingway was thinking consciously about varying the placement of dependent clauses in these sentences—at least not when he first drafted them. No doubt he was responding to an instinctive sense of what would make the paragraph flow. We, too, should do our best to follow the ebb and flow of our rhythmic instincts, but to ensure that we have the skills needed to follow our instincts, we should also practice varying the structures and lengths of our sentences as rigorously as concert pianists practice scales. While I don’t think Hemingway can be held accountable for the current dominance of simple sentence patterns, I do think it’s true that many of his followers have tended to use syntax as simple as their master’s diction. This is certainly true of Raymond Carver—or, at least, of Raymond Carver as edited by Gordon Lish (as D.T. Max has revealed, Carver’s hyper-minimalist style was due largely to Lish’s drastic editing)—and it is also true of many of the writers who were influenced by the stories in Will You Please Be Quiet, Please? and What We Talk About When We Talk About Love . But the best of Hemingway’s followers use syntax nearly as complexly. Even Carver, once he no long-er allowed Lish to edit his work, varied his sentence structure and length considerably more than many of Hemingway’s other disciples (not to mention Carver’s own devotees). Witness the opening paragraph of “Menudo,” whose four sentences use three different structures and vary in length from 4 words to 35. I can’t sleep, but when I’m sure my wife Vicky is asleep, I get up and look through our bedroom window, across the street, at Oliver and Amanda’s house. Oliver has been gone for three days, but his wife Amanda is awake. She can’t sleep either. It’s four in the morning, and there’s not a sound outside—no wind, no cars, no moon even—just Oliver and Amanda’s place with the lights on, leaves heaped up under the front windows. There’s nothing wrong with simplicity, in short, if it’s only apparent, not actual. The best simple writing is, at its deepest level, the level of structure, complex. So if we can’t blame the current tendency toward simplicity of syntax on Hemingway’s example, or even on Carver’s, why is it so dominant? It’s not, I’m sure, because we lack the linguistic skills to write more complexly (provided, of course, that we practice those skills). And it’s not, I hope and pray, because we agree with Robert Bly’s ludicrous assertion that “The use of subordinate clauses in sentences reveals the writer’s tendency to fascism.” One reason simple syntax dominates our writing, I believe, is that such sentences are just plain easier to write. They take less effort, less thought. Plus, there’s less risk of grammatical mistakes or—a worse crime in these dumbed-down times—of appearing pretentious. To some of us, it seems, writing a compound-complex sentence is about as embarrassing as wearing an ascot to a hoedown. But I suspect the most important reason we overuse simple structures is that we’re excessively afraid of not writing clearly. Often, in the struggle to express a complicated, only half-understood idea or emotion, we sacrifice the truth we’re trying to convey in order to write simply and clearly. As Wright Morris has said, “When we give up what is vague in order to be clear, we may have given up the motive for writing.” Donald Barthelme also questions the value, even the possibility, of creating art that is simple and clear. “However much the writer might long to be, in his work, simple, honest, and straightforward,” he says, “these virtues are no longer available to him. He discovers that in being simple, honest, and straightforward … he speaks the speakable, whereas what we are looking for is the as-yet unspeakable, the as-yet unspoken.” So am I—or Morris or Barthelme—advocating the overthrow of English grammar and the production of vague, convoluted prose? Hardly. What we are advocating, however, is a conscious struggle against our natural inclination to simplify, for the sake of clarity and ease of reading, the complex, uncertain ideas and emotions that constitute our experience. And the best way to struggle against this inclination is to struggle against our tendency toward simplicity in syntax. The more we experiment with syntax, then, the more opportunities we give ourselves to discover our thoughts and express what would otherwise either remain vague or be sacrificed in the name of clarity. Thus, altering our syntax does more than help us write flowing prose; it allows us to get our thoughts off the normal track on which they run. Syntax is nothing if not the very structure of our thought, so if we change the way we think, we can sometimes change what we think. But don’t take my word for it; take Yeats’s. In the introduction to his collected plays, he wrote, “As I altered my syntax I altered my intellect.” Morris also believes that changing our syntax changes the way we think. According to him, “syntax shapes the mind … and does our thinking for us. If the words are rearranged, the workings of the mind are modified.” And if the words are rearranged, the rhythm of those words is modified, too, of course. According to Robert Hass, it’s this alteration in rhythm, more than the alteration in meaning, that changes our intellect. “New rhythms,” he has said, “are new perceptions.” In any case, the more we concentrate on altering our syntax, the more we free ourselves to discover other modes of thought. I’m not sure I’d go as far as Yeats, Morris, and Hass do, though, and assert that changing our syntax actually changes our intellect. Rather, I believe that as we alter our syntax, we discover our intellect—i.e., we find ways to say what we always knew but never knew we knew, our deepest beliefs and feelings. And it just may be that we discover not only the self but also the world. Bertrand Russell certainly believed syntax revealed the nature of outer as well as inner reality, for he concludes his An Inquiry Into Meaning and Truth with these words: “For my part, I believe that, partly by means of study of syntax, we can arrive at considerable knowledge concerning the structure of the world.” Given this relationship between syntax, thought, and discovery of both self and world, it shouldn’t be so surprising that some of our greatest writers blossomed when they abandoned their native languages to write their work. As Morris says, “In this release from the overfamiliar, the apparently exhausted, and immersion into new resources, we may understand better than we did in the past the flowering of a talent like Conrad’s. The new and strange language is part of a new consciousness.” Nabokov is another example. He was so dissatisfied with his original Russian version of Lolita that he destroyed it. Only when he began to rewrite the novel in English, he says, did he find the syntax appropriate for the book, the syntax that made the book conform to what he calls “its prefigured contour and color.” We may not alter our own intellects when we alter our syntax, but by discovering and expressing them, we just may alter our readers’ intellects. Indeed, it’s possible that one of the things we talk about when we talk about flow is the feeling that the writer’s syntax is altering our consciousness, making us think—and therefore feel—in new ways.
光流的概念是Gibson在1950年首先提出来的。 它是空间运动物体在观察成像平面上的像素运动的瞬时速度，是利用图像序列中像素在时间域上的变化以及相邻帧之间的相关性来找到上一帧跟当前帧之间存在的对应关系，从而计算出相邻帧之间物体的运动信息的一种方法。 一般而言，光流是由于场景中前景目标本身的移动、相机的运动，或者两者的共同运动所产生的。 当人的眼睛观察运动物体时， 物体的景象在人眼的视网膜上形成一系列连续变化的图像， 这一系列连续变化的信息不断“流过”视网膜（即图像平面），好像一种光的“流”，故称之为光流（optical flow）。光流表达了图像的变化，由于它包含了目标运动的信息，因此可被观察者用来确定目标的运动情况。 研究光流场的目的就是为了 从图片序列中近似得到不能直接得到的运动场 。运动场，其实就是物体在三维真实世界中的运动；光流场，是运动场在二维图像平面上（人的眼睛或者摄像头）的投影。 那通俗的讲就是通过一个图片序列，把 每张图像中每个像素的运动速度和运动方向 找出来就是光流场。那怎么找呢？咱们直观理解肯定是：第t帧的时候A点的位置是(x 1 , y 1 )，那么我们在第t+1帧的时候再找到A点，假如它的位置是(x 2 ,y 2 )，那么我们就可以确定A点的运动了：(u x , v y ) = (x 2 , y 2 ) - (x 1 ,y 1 )。 那怎么知道第t+1帧的时候A点的位置呢？ 这就存在很多的光流计算方法了。 1981年，Horn和Schunck创造性地将二维速度场与灰度相联系，引入光流约束方程，得到光流计算的基本 算法 。人们基于不同的理论基础提出各种光流计算方法，算法性能各有不同。Barron等人对多种光流计算技术进行了总结，按照理论基础与数学方法的区别把它们分成四种： 基于梯度的方法、基于匹配的方法、基于能量的方法、基于相位的方法。 近年来 神经动力学方法 也颇受学者重视。 其他的咱们先不说了，回归应用吧（呵呵，太高深了，自己说不下去了）。OpenCV中实现了不少的光流算法。 1）calcOpticalFlowPyrLK 通过金字塔Lucas-Kanade 光流方法计算某些点集的光流（稀疏光流）。理解的话，可以参考这篇论文：”Pyramidal Implementation of the Lucas Kanade Feature TrackerDescription of the algorithm” 2）calcOpticalFlowFarneback 用Gunnar Farneback 的算法计算稠密光流（即图像上所有像素点的光流都计算出来）。它的相关论文是：Two-Frame Motion Estimation Based on PolynomialExpansion 3）CalcOpticalFlowBM 通过块匹配的方法来计算光流。 4）CalcOpticalFlowHS 用Horn-Schunck 的算法计算稠密光流。相关论文好像是这篇：”Determining Optical Flow” 5）calcOpticalFlowSF 这一个是2012年欧洲视觉会议的一篇文章的实现：SimpleFlow: A Non-iterative, Sublinear Optical FlowAlgorithm，工程网站是： http://graphics.berkeley.edu/papers/Tao-SAN-2012-05/ 在OpenCV新版本中有引入。 稠密光流需要使用某种插值方法在比较容易跟踪的像素之间进行插值以解决那些运动不明确的像素 ，所以它的计算开销是相当大的。而对于稀疏光流来说，在他计算时需要在被跟踪之前指定一组点（容易跟踪的点，例如角点），因此在使用LK方法之前我们需要配合使用cvGoodFeatureToTrack()来寻找角点，然后利用金字塔LK光流算法，对运动进行跟踪。但个人感觉，对于少纹理的目标，例如人手，LK稀疏光流就比较容易跟丢。 IJCV2011有一篇文章，《 A Database and Evaluation Methodology for Optical Flow 》里面对主流的光流算法做了简要的介绍和对不同算法进行了评估。网址是： http://vision.middlebury.edu/flow/ 感觉这个文章在光流算法的解说上非常好，条例很清晰。想了解光流的，推荐看这篇文章。另外，需要提到的一个问题是，光流场是图片中每个像素都有一个x方向和y方向的位移，所以在上面那些光流计算结束后得到的光流flow是个和原来图像大小相等的双通道图像。那怎么可视化呢？这篇文章用的是Munsell颜色系统来显示。 http://blog.sina.com.cn/s/blog_80ce3a550102vdim.html http://blog.csdn.net/zouxy09/article/details/8683859 Motion estimation and video compression have developed as a major aspect of optical flow research. While the optical flow field is superficially similar to a dense motion field derived from the techniques of motion estimation, optical flow is the study of not only the determination of the optical flow field itself, but also of its use in estimating the three-dimensional nature and structure of the scene, as well as the 3D motion of objects and the observer relative to the scene, most of them using the Image Jacobian . https://en.wikipedia.org/wiki/Optical_flow
欢迎批评指正。 Velocity–vorticity correlation structure in turbulent channel flow Jun Chen,Fazle Hussain,Jie Pei and Zhen-Su She (2014). Journal of Fluid Mechanics Volume 742 , March 2014 pp 291-307 http://journals.cambridge.org/action/displayAbstract?aid=9179891
ABSTRACT Flow Mapping, also known as spatial interaction data visualization, has become widely used for exploratory spatio-temporal data analysis to understand complex spatial phenomena such as human migration, commercial trading, and social networks. The unitary flow mapping architecture, in which data storing, computing and representation are deployed in a single computer, is facing the challenges being brought from increasing data scale, higher timing demand, computing complexity of visual clutter detecting and integrating with other GIS and spatio-temporal analysis tools. In this paper, a novel 3-tiers flow mapping service architecture is proposed. In this architecture, flow data integration tier provide a unified data access interface for variant data sources; flow mapping models tier provide a computing resource pool to support different flow mapping algorithms and scalable computing capability; and result visualization tier to view map interactively. In this paper, we expand the OGC Web Map Services(WMS) standard protocol to support spatio-temporal interaction data visualization and analytics, and integrate WMS-based flow mapping service with other map resources by JavaScript toolkits in browsers. This architecture is validate to be improved in performance and scalability by three typical application cases. 1. Guo, D., et al. WMS-Based Flow Mapping Services. in Services (SERVICES), 2012 IEEE Eighth World Congress. 2012. 全文下载： WMS-based FM services.pdf
Zengsheng Ma, Shiguo Long , Yong Pan, Yichun Zhou Nanoindentation tests in Ni thin films with 3000 nm thickness were performed under the maximum load ranging from 1000 to 9000 m N to investigate the dependence of the Flow stress and Young’s modulus upon the indentation scale under zero and 10% tensile strain. The results show that, the Flow stress and Young’s modulus all display the indentation depth dependence. Furthermore, an analytical relationship between the Young’s modulus E and hardness H for Ni thin films is established based on the conventional depth-sensing indentation method of Oliver and Pharr. ICHMM2008, 195-199, (ISTP) Flow stress and Young's modulus of Ni films in nanoindentation creep.pdf
Traffic and Granular Flow '11 28 September - 01 October, 2011 Uzkoe, Moscow, Russia Russian Academy of Sciences Call for papers Paper Submission Deadline: April 30, 2011 TGF'11 The Ninth international Conference on Traffic and Granular Flow '11 September 28 - October 1, 2011, Moscow, RUSSIA The Conference on Traffic and Granular Flow '11 (TGF'11) is the ninhth of an international series of conferences held previously in Jülich (1995), Duisburg (1997), Stuttgart (1999), Nagoya (2001), Delft (2003), Berlin (2005), Paris (2007) and Shanghai (2009). TGF'11 will be held in Moscow, Russia. Moscow is the biggest city and the largest commercial and financial center in Russia, is also the center of research in traffic dynamics and related fields. TGF'11 will take place in the Uzkoe Hotel of Russian Academy of Science, Moscow, Russia. The purpose of this conference is to facilitate new ideas by considering the similarities of traffic and granular flow. Recent achievements in modeling, computer simulation and phenomenology will be presented, and possible future applications in traffic control and creation of ITSs will be discussed. Topics include highway traffic flow, granular flow, traffic on Internet networks, and pedestrian dynamics as well as collective dynamics of biological systems. The importance of exploring the interrelations between these fields is constantly increasing. This conference offers the opportunity to stimulate interdisciplinary research, exchange ideas, and meet many experts in these areas of research. Conference Organizers · Keldysh Institute of Applied Mathematics (Russian Academy Of Science) · Moscow Technical University of Communications and Informatics Sponsors · Russian Academy of Science · Russian Foundation for Basic Research Topics · Highway and urban vehicular traffic · Pedestrian traffic and evacuation dynamics · Granular flow · Collective motion in biological systems · Complex networks: transportation networks, internet, epidemics, social networks.. · Cellular automata applied to the above fields · Intelligent Traffic Systems (ITS) Submission of papers: Contributors are invited to submit their manuscripts online. Use this form to upload papers: Open form Main information Title of the paper Keywords (please enter a maximum of 5 keywords) Name of the Contact Author Email of the Contact Author Select your file here: Author(s) Author's name Author's affiliation Author's postal address Author's email Author's name here Add author CAPTCHA Enter the characters shown in the picture below: ( refresh ) Contributions must be uploaded to the evaluation website by April 30, 2011 in either DOC, DOCX or PDF formats. Submission implies that the manuscript has not been published previously, and is not currently submitted for publication elsewhere. The first page of the paper should specify: title of the paper, name of the author(s) and their affiliation, postal address and email address for each author as well as the name of the Contact Author and a maximum of 5 topical keywords that would best represent the content of the paper. Please cite the name of the Conference on the first page. Welcome to Moscow! Best regards, Chair of Program Committee Acad. of RAS V. V. Kozlov (Vice President, Presidium of Russian Academy of Sciences, Russia) Chair of Organizing Committee Acad. of RAS A. S. Bugaev (Head of Department, MIPT, Russia)
http://www.flowthefilm.com/trailer About the Film Irena Salina's award-winning documentary investigation into what experts label the most important political and environmental issue of the 21st Century - The World Water Crisis. Salina builds a case against the growing privatization of the world's dwindling fresh water supply with an unflinching focus on politics, pollution, human rights, and the emergence of a domineering world water cartel. Interviews with scientists and activists intelligently reveal the rapidly building crisis, at both the global and human scale, and the film introduces many of the governmental and corporate culprits behind the water grab, while begging the question "CAN ANYONE REALLY OWN WATER?" Beyond identifying the problem, FLOW also gives viewers a look at the people and institutions providing practical solutions to the water crisis and those developing new technologies, which are fast becoming blueprints for a successful global and economic turnaround. On December 10th, 2008 FLOW was invited to screen at the United Nations as part of the 60th Anniversary of the Declaration of Human Rights. Watch the video here: FLOW at the UN
2010, Proceedings of the 36th International MATADOR Conference , 6 , Pages 227-230 Modeling of hard turning: effect of tool geometry on cutting force Z.Y. Shi, Z.Q. Liu, C.M. Cao Abstract. Hard machining for manufacturing dies and molds offers various advantages, but the productivity is often limited, mainly by tool life. This study investigates the influence of cutting tool geometry on the cutting forces by utilizing finite element simulations (FEM). A set of cutting conditions in numerical FEM were conducted by using four different shaped cutting tools and axial force, radial force and tangential force were found. The results of this research help to explain the conclusion that for cylindrical control, the equation of the actual geometry of the S-shaped inserts involved in cutting is a sphere; that of C-shaped, D-shaped and Tshaped inserts involved in cutting is an ellipsoid with different lengths of short-half axis. Keywords : tool geometry, material flow stress, short-half-axial, cutting force FULL TEXT
2006年的时候，做人脸跟踪AAM项目，参考了一篇叫做“L-K算法20年”的文章 ，看得不知所云。现在再看，觉得他们有故弄玄虚的意思。比如说，既然大家都在Tamplate上计算梯度下降，那为什么还要讲那么多正向warp，反向warp的。反正当时是看得恶心了。我还是按自己的理解写写吧，也许写得不对，请大家指正。 L-K算法（或称光流法）本质上是一种基于梯度下降的优化方法。对于梯度下降法我的理解是这样： 对于一个标量函数y=f(x)，可以看作是一个曲线，在一个很小的范围内可以认为是直线（局部线性），求函数最小值的下降方向为梯度的负方向Δx=-Δy/tan(th)。对于一维函数梯度tan(th)=dy/dx，它的倒数很容易得到。而对于x是向量的情况，对应的梯度的"倒数"就变成求逆矩阵了。比如图像每个点的梯度(dI/dx,dI/dy)就是一个矢量，一个点求逆矩阵显然不可以，但是一个图像块内的N的点构成2*N矩阵，就可以求伪逆了（最小二乘法）。对于变量x是更高维的情况，比如函数y是和很多变量相关的，每个点的梯度dy/dx由变量x的每个分量有关，变成了高维矢量(dy/dxi)，尽管这时y和x的变化关系可能无法线性表达，但总是可以通过中间变量利用链式法则求dy/dx，或者利用数值法求解，比如给xi一个小的增量，y也相应产生一个增量，二者比值可以近似梯度矢量dy/dxi，这样仍然可以得到上边所说的Δx伪逆解。 实际上图像中的物体都可以表达为局部图像块的集合，比如利用三角剖分或者稀疏的特征点，对这些区域单独使用L-K算法，然后用全局的模型参数进行拟合（去除坏的匹配块），这样就有可能实现复杂的目标比如人脸图像的跟踪。著名的AAM人脸建模方法基本上就是这个思路。 具体算法的推导可参考我总结的文档 L-K算法文档 。 关于文档最后的那个方程组 Δp=dp*E 的说明： 1 图像和模板的差是图像匹配的原动力，它分别和 dP 矩阵中的的6个N维矢量做内积得到参数p的更新值 p=p+Δp ，从而驱动模板动起来。这个求解过程是个迭代过程，无法保证收敛到全局最优解。用多分辨率法求解是个好的选择，可参见OpenCV里的光流法文档。 2用来跟踪的光流法是用前一帧的图像块作为模板，用当前帧图像进行匹配的，这个过程要实时计算二阶逆矩阵（p的位数是2）。而在有些应用中， dP 的步骤可以只在模板T上离线进行，可称作训练。模板也可以扩展为一个包含更多参数的模型，比如著名的Active Appearance Model。有时warp过程无法显式表达，计算 dP 可以用给p加扰动(perturbation)的方法。CMU的文章把Cootes的那套AAM用L-K光流的框架来描述，据他们自称，电影Avatar就是用他们的方法做人脸特征跟踪的。 3 参考文章1中把H=J T J叫作Hessian矩阵，它是对J求伪逆过程的一个副产品，和表达二阶偏导的Hessian阵不同。不过H的作用很重要，它能反映图像数据的统计特性。如果不幸H是奇异的，也就是说无法求逆矩阵，那么说明这个图像模板包含的各个梯度方向的信息不足以进行跟踪应用。对于光流应用（p的维数是2，只有平移运动），H的对应的特征值(eigenvalue)都要远大于0，才是“好的特征”（角点），这个特性又被用来做corner detection。有著名的文章Good features to track专门讨论此事。 参考文献: Simon Baker and Iain Matthews. Lucas-Kanade 20 years on: A unifying framework. Jianbo Shi and Carlo Tomasi. Good features to track.
In mathematics a Vector field is a construction in vector calculus which associated a vector to every point in a subset of Euclidean space. Vector fields are often used in pysics to model, for example, the speed and direction of a moving fluid thoughout space, or the strength and direction of some force, such as the magnitic or gravitational force, as it changes from point to point.
标签: flow
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