Items of some interest:

These are my recent Pin​board​.in links:

  • Jonathan Lethem’s ‘Neote­nous Aes­thetic” — Mis­ter Bit — Wired​.it

    ‘Dur­ing the brief, but very inter­est­ing Q&A ses­sion, Lethem argued that inter­net cul­ture brought the “closet into the open”, that is, it gave ephemera, triv­i­al­i­ties, and every­day activ­i­ties “A new kind of vis­i­bil­ity”. “Peo­ple have always been pro­duc­ing weird stuff and have always been engag­ing in arcane activ­i­ties,” Lethem remarked. “What is really new is the fact the now we can see it. We can see it all. We can quan­tify what we do — or not do — online.” Lethem men­tioned the uncanny abil­ity to track, in real time, “how many books I am not sell­ing on Ama­zon”. “Real­ity has acquired a new level of mea­sur­a­bil­ity”. “The activ­i­ties we per­form in our dig­i­tal age are not nec­es­sar­ily new. What is new is that. We. Can. See. Them. All.”.’

    one-​​measures-​​a-​​circle inter­per­me­ation access local­ism
  • Sex, Oil, and Video­tape | Mother Jones

    “Loom­ing over Saylor’s con­fronta­tion with Bolen­baugh was the EPA’s Sep­tem­ber 27 cleanup dead­line, and it appears that Enbridge and its con­trac­tors were feel­ing the pres­sure as it drew near. In early Sep­tem­ber, after the Michi­gan Mes­sen­ger pub­lished its exposé on the use of undoc­u­mented work­ers by Hall­mark Indus­trial, another group of work­ers employed by a dif­fer­ent Enbridge con­trac­tor came for­ward with detailed sto­ries of how they had been instructed to con­ceal oil at the same site. Work­ers would land on an island, they said, remove all veg­e­ta­tion, and then lay out absorbent pom-​​poms, all per EPA reg­u­la­tions. But once the top layer of oil was absorbed, they were instructed to rake dirt over the area to make it appear as though it had been dug out. One worker described his super­vi­sor show­ing him the process step-​​by-​​step, con­clud­ing with sprin­kling a thin layer of dirt on top. “He said, ‘There, now they can’t see it. It is clean,’” the worker told the Mes­sen­ger. Another worker described being told to cover pock­ets of oil with leaves and sticks. As a last step, such areas were cor­doned off with cau­tion tape.”

    oil­spill Kala­ma­zoo local whistle­blower
  • [1204.4200] Dis­crete Dynam­i­cal Genetic Pro­gram­ming in XCS

    “A num­ber of rep­re­sen­ta­tion schemes have been pre­sented for use within Learn­ing Clas­si­fier Sys­tems, rang­ing from binary encod­ings to neural net­works. This paper presents results from an inves­ti­ga­tion into using a dis­crete dynam­i­cal sys­tem rep­re­sen­ta­tion within the XCS Learn­ing Clas­si­fier Sys­tem. In par­tic­u­lar, asyn­chro­nous ran­dom Boolean net­works are used to rep­re­sent the tra­di­tional condition-​​action pro­duc­tion sys­tem rules. It is shown pos­si­ble to use self-​​adaptive, open-​​ended evo­lu­tion to design an ensem­ble of such dis­crete dynam­i­cal sys­tems within XCS to solve a num­ber of well-​​known test problems.”

    genetic-​​programming learning-​​classifier-​​systems representation-​​theory design-​​patterns boolean-​​networks nudge-​​targets nice
  • Why Is Darwin’s Tan­gled Bank Tan­gled? : 13.7: Cos­mos And Cul­ture : NPR

    Sad to hear him still phras­ing this sim­ple truth so obscurely: Not “Because, on the scale of mol­e­c­u­lar bind­ing site recog­ni­tion, say a few tens of angstroms in length, height and width and sev­eral other fea­tures such as polar­ity, van-​​der-​​Waal forces, and so on, there are far fewer effec­tively dif­fer­ent mol­e­c­u­lar shapes than there are kinds of mol­e­cules.“ … but “Because there are fewer sto­ries than there are facts.”

    oh-​​stu pragmatism-it-ain’t philosophy-​​of-​​science
  • Math Notes | Futil­ity Closet

    So for finite sequences of dig­its, which sequences are such that the most right-​​truncated sub­strings are prime? Which are such that the most right-​​repeating exten­sions are prime?

    nudge-​​targets number-​​theory indirect-​​link
  • Home — Scal­able and Mod­u­lar Archi­tec­ture for CSS

    “I’ve been ana­lyz­ing my process (and the process of those around me) and fig­ur­ing out how best to struc­ture code for projects on a larger scale. What I’ve found is a process that works equally well for sites small and large. Learn how to struc­ture your CSS to allow for flex­i­bil­ity and main­tain­abil­ity as your project and your team grows.”

    css tuto­r­ial best-​​practices graphic-​​design via-​​trek
  • [1204.3678] Crowd Mem­ory: Learn­ing in the Collective

    “Crowd algo­rithms often assume work­ers are inex­pe­ri­enced and thus fail to adapt as work­ers in the crowd learn a task. These assump­tions fun­da­men­tally limit the types of tasks that sys­tems based on such algo­rithms can han­dle. This paper explores how the crowd learns and remem­bers over time in the con­text of human com­pu­ta­tion, and how more real­is­tic assump­tions of worker expe­ri­ence may be used when design­ing new sys­tems. We first demon­strate that the crowd can recall infor­ma­tion over time and dis­cuss pos­si­ble impli­ca­tions of crowd mem­ory in the design of crowd algo­rithms. We then explore crowd learn­ing dur­ing a con­tin­u­ous con­trol task. Recent sys­tems are able to dis­guise dynamic groups of work­ers as crowd agents to sup­port con­tin­u­ous tasks, but have not yet con­sid­ered how such agents are able to learn over time. We show, using a real-​​time gam­ing set­ting, that crowd agents can learn over time, and ‘remem­ber’ by pass­ing strate­gies from one gen­er­a­tion of work­ers to the next, despite high turnover rates in the work­ers com­pris­ing them. We con­clude with a dis­cus­sion of future research direc­tions for crowd mem­ory and learning.”

    crowd­sourc­ing learn­ing agent-​​based collective-​​intelligence mem­ory nudge-​​targets
  • [0911.1582] Manip­u­lat­ing Tour­na­ments in Cup and Round Robin Competitions

    “In sports com­pe­ti­tions, teams can manip­u­late the result by, for instance, throw­ing games. We show that we can decide how to manip­u­late round robin and cup com­pe­ti­tions, two of the most pop­u­lar types of sport­ing com­pe­ti­tions in poly­no­mial time. In addi­tion, we show that find­ing the min­i­mal num­ber of games that need to be thrown to manip­u­late the result can also be deter­mined in poly­no­mial time. Finally, we show that there are sev­eral dif­fer­ent vari­a­tions of stan­dard cup com­pe­ti­tions where manip­u­la­tion remains polynomial.”

    algo­rithms eco­nom­ics game-​​theory nudge-​​targets
  • Intro­duc­ing the Jour­nal of Dig­i­tal Human­i­ties — ProfHacker — The Chron­i­cle of Higher Education

    “If the con­tents of the inau­gural issue—which range from an essay argu­ing that human­ists need to under­stand and inter­pret quan­ti­ta­tive data to a review of the Word­Seer text analy­sis tool—fall out­side your usual schol­arly domain, then cer­tainly the journal’s edi­to­r­ial and pub­lish­ing appa­ra­tus will piqué your interest. As Dan Cohen explained in a sep­a­rate blog post, the jour­nal oper­ates under the model of catch­ing the good—of find­ing sub­stan­tive and valu­able dig­i­tal human­i­ties work “in what­ever for­mat, and wher­ever, it exists.” Blogs, pod­casts, Twit­ter con­ver­sa­tions, slideshows, and so on, these are all venues in which sig­nif­i­cant and, though I hate to use such an ungainly word, impact­ful work is being done. The reg­u­lar and guest edi­tors “catch” this work, and then pro­vide lay­ers of eval­u­a­tion and review before it appears in JDH.”

    digital-​​humanities jour­nal to-​​read two-​​cultures-​​only-​​one-​​of-​​which-​​can-​​write
  • [1005.4159] The Com­plex­ity of Manip­u­lat­ing $k$-Approval Elections

    “An impor­tant prob­lem in com­pu­ta­tional social choice the­ory is the com­plex­ity of unde­sir­able behav­ior among agents, such as con­trol, manip­u­la­tion, and bribery in elec­tion sys­tems. These kinds of vot­ing strate­gies are often tempt­ing at the indi­vid­ual level but dis­as­trous for the agents as a whole. Cre­at­ing elec­tion sys­tems where the deter­mi­na­tion of such strate­gies is dif­fi­cult is thus an impor­tant goal. …”

    vot­ing game-​​theory design-​​patterns mechanism-​​design nudge-​​targets
  • [0903.1147] Tetravex is NP-​​complete

    “Tetravex is a widely played one per­son com­puter game in which you are given $n^2$ unit tiles, each edge of which is labelled with a num­ber. The objec­tive is to place each tile within a $n$ by $n$ square such that all neigh­bour­ing edges are labelled with an iden­ti­cal num­ber. Unfor­tu­nately, play­ing Tetravex is com­pu­ta­tion­ally hard. More pre­cisely, we prove that decid­ing if there is a tiling of the Tetravex board is NP-​​complete. Decid­ing where to place the tiles is there­fore NP-​​hard. This may help to explain why Tetravex is a good puz­zle. This result com­pli­ments a num­ber of sim­i­lar results for one per­son games involv­ing tiling. For exam­ple, NP-​​completeness results have been shown for: the offline ver­sion of Tetris, KPlumber (which involves rotat­ing tiles con­tain­ing draw­ings of pipes to make a con­nected net­work), and short­est slid­ing puz­zle prob­lems. It raises a num­ber of open ques­tions. For exam­ple, is the infi­nite ver­sion Turing-​​complete? How do we gen­er­ate Tetravex prob­lems which are truly puz­zling as ran­dom NP-​​complete prob­lems are often sur­pris­ing easy to solve? Can we observe phase tran­si­tion behav­iour? What about the com­plex­ity of the prob­lem when it is guar­an­teed to have an unique solu­tion? How do we gen­er­ate puz­zles with unique solutions?”

    mathematical-​​recreations computational-​​complexity algo­rithms nudge-​​targets
  • [1204.4286] Fair Allo­ca­tion With­out Trade

    “We con­sider the age-​​old prob­lem of allo­cat­ing items among dif­fer­ent agents in a way that is effi­cient and fair. Two papers, by Dolev et al. and Ghodsi et al., have recently stud­ied this prob­lem in the con­text of com­puter sys­tems. Both papers had sim­i­lar mod­els for agent pref­er­ences, but advo­cated dif­fer­ent notions of fair­ness. We for­mal­ize both fair­ness notions in eco­nomic terms, extend­ing them to apply to a larger fam­ily of util­i­ties. Not­ing that in set­tings with such util­i­ties effi­ciency is eas­ily achieved in mul­ti­ple ways, we study notions of fair­ness as cri­te­ria for choos­ing between dif­fer­ent effi­cient allo­ca­tions. Our tech­ni­cal results are algo­rithms for find­ing fair allo­ca­tions cor­re­spond­ing to two fair­ness notions: Regard­ing the notion sug­gested by Ghodsi et al., we present a polynomial-​​time algo­rithm that com­putes an allo­ca­tion for a gen­eral class of fair­ness notions, in which their notion is included. For the other, sug­gested by Dolev et al., we show that a com­pet­i­tive mar­ket equi­lib­rium achieves the desired notion of fair­ness, thereby obtain­ing a polynomial-​​time algo­rithm that com­putes such a fair allo­ca­tion and solv­ing the main open prob­lem raised by Dolev et al.”

    eco­nom­ics game-​​theory fair­ness algo­rithms phi­los­o­phy design-​​patterns
  • Why is Esti­mat­ing so Hard? | 8th Light

    “It turns out that we don’t know the pro­ce­dure. We haven’t got any clue to just how dif­fi­cult the pro­ce­dure is. We aren’t com­put­ers. We don’t fol­low pro­ce­dures. And so com­par­ing the com­plex­ity of the man­ual task, to the com­plex­ity of the pro­ce­dure is invalid. This is one of the rea­sons that esti­mates are so hard, and why we get them wrong so often. We look at a task that seems easy and esti­mate it on that basis, only to find that writ­ing down the pro­ce­dure is actu­ally quite intri­cate. We blow the esti­mate because we esti­mate the wrong thing.”

    esti­ma­tion agile-​​practices philosophy-​​of-​​engineering man­age­ment self-​​definition plan­ning
  • [1204.4374] Higher Order City Voronoi Diagrams

    “We inves­ti­gate higher-​​order Voronoi dia­grams in the city met­ric. This met­ric is induced by quick­est paths in the L1 met­ric in the pres­ence of an accel­er­at­ing trans­porta­tion net­work of axis-​​parallel line segments. …”

    computational-​​geometry algo­rithms voronoi-​​diagrams diver­sity network-​​theory nudge-​​targets
  • Topic mod­el­ing made just sim­ple enough. | The Stone and the Shell

    “Com­puter sci­en­tists make LDA seem com­pli­cated because they care about prov­ing that their algo­rithms work. And the proof is indeed brain-​​squashingly hard. But the prac­tice of topic mod­el­ing makes good sense on its own, with­out proof, and does not require you to spend even a sec­ond think­ing about “Dirich­let dis­tri­b­u­tions.” When the math is approached in a prac­ti­cal way, I think human­ists will find it easy, intu­itive, and empow­er­ing. This post focuses on LDA as short­hand for a broader fam­ily of “prob­a­bilis­tic” tech­niques. I’m going to ask how they work, what they’re for, and what their lim­its are.”

    text-​​processing clas­si­fi­ca­tion algo­rithms lovely two-​​cultures-​​only-​​one-​​of-​​which-​​can-​​write
  • Math­e­mati­cians are Giraffe Hunters by Barry Mazur | berfrois

    “No won­der life (i.e., the thing that my once 10-​​year old niece referred to as “the thing that isn’t fair”) comes to us as a fil­i­gree of ash sto­ries. Walk­ing down the street past a cou­ple in con­ver­sa­tion, an over­heard mor­pheme, a mere glance at a wrongly but­toned rain­coat, sparks a nar­ra­tive in our imag­i­na­tion. Ask any ques­tion begin­ning with “why?” and the answer will surely be a story, or it will be embed­ded in a story. Or, at the very least, it will offer a tempt­ing thread for some story that you your­self will hold onto, embell­ish even, as you try to absorb the answer. We inter­po­late between such frag­ments. This is, for many of us, sim­ply the way we think. What about the “why ques­tions” in sci­ence, in logic, in math­e­mat­ics? We should acknowl­edge how they are often “what ques­tions” or “how ques­tions” in dis­guise. Or how they slide down into such ques­tions, as the ever-​​elusive, ever-​​illusory quest for an X that actu­ally causes a Y dis­solves. Some of the more sat­is­fy­ing answers to sci­en­tific “why” ques­tions involves deft rephras­ing. “Why is the sky blue?” is replaced by the ques­tion “what is the func­tion that describes scat­ter­ing ampli­tude as depen­dent on wave-​​length”?”

    math­e­mat­ics philosophy-​​of-​​mathematics sto­ry­telling prag­ma­tism theory-​​and-​​practice-​​sitting-​​in-​​a-​​tree what-​​is-​​it-​​good-​​for-​​hunh

Items of some interest:

These are my recent Pin​board​.in links:


  • you-​​are-​​supposed-​​to-​​have-​​read-​​that-​​young-​​man
  • Cyber­net­ick Inkwell · On a def­i­n­i­tion of “open humanities”

    “The dig­i­tal human­i­ties are a part of the open human­i­ties to the extent that those same val­ues are held, though of course the purely dig­i­tal ele­ments (the code, the markup, the hard­ware) are unique to the dig­i­tal human­i­ties and live largely out­side of OH. That being said, much of DH—the com­mit­ment to open source, the col­lab­o­ra­tive nature of the field, the interdisciplinarity—is open.”

    open­ness digital-​​humanities the-​​inevitability-​​of-​​enclosures cultural-​​dynamics theory-​​as-​​code
  • Don’t Hold Your Breath | Paul Shep­heard | Archi­tect and writer | Words

    “…Nar­ra­tives are bet­ter than thumps, is the mes­sage; and in the field of human rela­tions this might well be so, but here’s the rub. Nature’s not a per­son. Nature’s not a mother. We are not fight­ing it but liv­ing it. The indus­trial land­scapes pur­sued with such ter­rific thor­ough­ness, the agri­cul­tural deserts as well as the sub­urbs, the mine­fields as well as the wind farms, the cities them­selves, are the out­comes not of rage but of sto­ries, nar­ra­tives in the dream of the human dom­i­na­tion of the world. That’s why I hug the boy’s head. It’s good that he sees him­self as a par­ti­cle of nature, a being rather than a human being, and his life as fun­da­men­tally con­sump­tive. He knows if he holds his breath he will die. He knows he must live in the present. So now I must try and teach him this: the bolt-​​ons and band-​​aids of the sus­tain­abil­ity move­ment that try to man­age our fear of the future are but another chap­ter in that book of dom­i­na­tion. It will not, in the face of the red giant, ulti­mately sus­tain. And nature as we know it now, in this snap­shot of human time, will not stay as it is, how­ever we try to pre­serve it.”

    paul-​​shepheard sus­tain­abil­ity crit­i­cism how-​​to-​​rite-​​gud
  • Grounds For Dis­per­sal | Paul Shep­heard | Archi­tect and writer | Words

    “Anonymity does not mean with­out deep con­tact, it means that the con­tact has no pre­empt­ing cer­e­mony. Col­lab­o­ra­tion, like­wise, is the proof of itself. It exists nei­ther before or after the moment it takes place, except in how it inflects your char­ac­ter. Inclu­sive­ness and par­tial­ity are sym­bi­otic, too. If par­tial is a move taken to out­flank hege­mony, the inclu­sive works to recom­bine dif­fer­ences. The para­doxes implicit in such terms are part of what makes them inter­est­ing. I’m try­ing to elu­ci­date a think­ing that is not dialec­tic, no longer depen­dent on oppo­si­tions, not look­ing for the right way. As one of the direc­tors of The­mepark, a Lon­don based fashion-​​architecture-​​photography-​​landscape com­bine said to me: “we are inter­ested in show­ing con­tent in its pure form.” At first I thought it was a joke, more of that London-​​Thing irony, but then I thought, what else is the mate­r­ial world but con­tent in its pure form? Today’s pho­tog­ra­phers, who mis­trust the Mag­num generation’s point-​​and-​​shoot real­i­ties, who set up every shot elab­o­rately, who treat land­scape, por­trait, action and spec­ta­cle as the same thing, are not being min­i­mal­ist. They are posit­ing the veloc­ity of the image.”

    paul-​​shepheard crit­i­cism style how-​​to-​​rite-​​gud
  • Mario Carpo: Post-​​Authorial Cre­ation | berfrois

    “This is where the design pro­fes­sions are increas­ingly feel­ing some dis­com­fort.  Design­ers like to design.  They like to be in charge of all aspects of what they cre­ate.  Many design­ers are noto­ri­ously con­trol freaks.  And rightly so: being in con­trol is their rai­son d’être.  Tra­di­tion­ally, design­ers “authored” objects and “autho­rized” their pro­duc­tion, repro­duc­tion, or mod­i­fi­ca­tion.  Their sig­na­ture had (it still has, by the way) bind­ing, legal value–implying autho­r­ial priv­i­leges pro­tected by law, and all the lia­bil­i­ties result­ing from that.  But once again, dig­i­tal tech­nolo­gies do not work that way.  When so many peo­ple can work together, who is in charge?  Who reaps the hon­ors?  Who pays the damages?”

    design con­trol planning-​​as-​​a-​​symptom mass-​​customization control-​​of-​​the-​​means-​​of-​​thought
  • Repub­li­can con­ser­vatism (com­plete rewrite) — Crooked Timber

    “The polit­i­cal impli­ca­tion, which has drawn some flak in the com­ments, but which I think is cor­rect is that there is no point in polit­i­cal engage­ment with author­i­tar­ian con­ser­v­a­tives. In a polit­i­cal envi­ron­ment where they are con­cen­trated in one party,politics is going to be a mat­ter the only strat­egy open to lib­er­als is to out­num­ber and out­vote them by peel­ing off as many periph­eral groups (for exam­ple, those who devi­ate from the approved cul­tural iden­tity in some way) as pos­si­ble. Obvi­ously, that’s an unpalat­able con­clu­sion in all sorts of ways, but I think it’s a valid one.”

    con­ser­vatism Repub­li­cans pol­i­tics nature-​​and-​​nurture-​​sittin-​​in-​​a-​​tree
  • Bot­tle the Infla­tion Mon­ster! — Crooked Timber

    ‘Fur­ther­more this seems to me to play once again into the view that ‘eco­nom­ics’ is tech­ni­cal and has right answers, while ‘pol­i­tics’ is emo­tive and con­tested, so stu­dents of the EU don’t have to talk about it.’

    eco­nom­ics infla­tion ped­a­gogy for-​​the-​​little-​​chilluns

Items of some interest:

These are my recent Pin​board​.in links:

Items of some interest:

These are my recent Pin​board​.in links:

Items of some interest…

These are my recent Pin​board​.in links:

  • [1112.6209] Build­ing high-​​level fea­tures using large scale unsu­per­vised learning

    We con­sider the prob­lem of build­ing detec­tors for high-​​level con­cepts using only unsu­per­vised fea­ture learn­ing. For exam­ple, we would like to under­stand if it is pos­si­ble to learn a face detec­tor using only unla­beled images down­loaded from the inter­net. To answer this ques­tion, we trained a sim­ple fea­ture learn­ing algo­rithm on a large dataset of images (10 mil­lion images, each image is 200×200). The sim­u­la­tion is per­formed on a clus­ter of 1000 machines with fast net­work hard­ware for one week. Exten­sive exper­i­men­tal results reveal sur­pris­ing evi­dence that such high-​​level con­cepts can indeed be learned using only unla­beled data and a sim­ple learn­ing algorithm.

    image-​​analysis image-​​segmentation unsupervised-​​learning learning-​​by-​​doing feature-​​extraction nudge-​​targets
  • [1105.0158] Detect­ing emer­gent processes in cel­lu­lar automata with excess information

    Many nat­ural processes occur over char­ac­ter­is­tic spa­tial and tem­po­ral scales. This paper presents tools for (i) flex­i­bly and scal­ably coarse-​​graining cel­lu­lar automata and (ii) iden­ti­fy­ing which coarse-​​grainings express an automaton’s dynam­ics well, and which express its dynam­ics badly. We apply the tools to inves­ti­gate a range of exam­ples in Conway’s Game of Life and Hop­field net­works and demon­strate that they cap­ture some basic intu­itions about emer­gent processes. Finally, we for­mal­ize the notion that a process is emer­gent if it is bet­ter expressed at a coarser granularity.

    emer­gence com­plex­ol­ogy cellular-​​automata signal-​​processing nudge-​​targets
  • [1008.0901] Con­ver­gence to global con­sen­sus in opin­ion dynam­ics under a non­lin­ear voter model

    We pro­pose a non­lin­ear voter model to study the emer­gence of global con­sen­sus in opin­ion dynam­ics. In our model, agent $i$ agrees with one of binary opin­ions with the prob­a­bil­ity that is a power func­tion of the num­ber of agents hold­ing this opin­ion among agent $i$ and its near­est neigh­bors, where an adjustable para­me­ter $alpha$ con­trols the effect of herd behav­ior on con­sen­sus. We find that there exists an opti­mal value of $alpha$ lead­ing to the fastest con­sen­sus for lat­tices, ran­dom graphs, small-​​world net­works and scale-​​free net­works. Qual­i­ta­tive insights are obtained by exam­in­ing the spa­tiotem­po­ral evo­lu­tion of the opin­ion clusters.

    agent-​​based social-​​dynamics network-​​theory com­plex­ol­ogy nudge-​​targets
  • [1110.4876] REBOUND: An open-​​source multi-​​purpose N-​​body code for col­li­sional dynamics

    REBOUND is a new multi-​​purpose N-​​body code which is freely avail­able under an open-​​source license. It was designed for col­li­sional dynam­ics such as plan­e­tary rings but can also solve the clas­si­cal N-​​body prob­lem. It is highly mod­u­lar and can be cus­tomized eas­ily to work on a wide vari­ety of dif­fer­ent prob­lems in astro­physics and beyond.

    sim­u­la­tion computational-​​science astro­physics numerical-​​methods sim­u­la­tor library open-​​source nudge-​​targets
  • [1112.5908] Query Answer­ing under Match­ing Depen­den­cies for Data Clean­ing: Com­plex­ity and Algorithms

    Match­ing depen­den­cies (MDs) have been recently intro­duced as declar­a­tive rules for entity res­o­lu­tion (ER), i.e. for iden­ti­fy­ing and resolv­ing dupli­cates in rela­tional instance $D$. A set of MDs can be used as the basis for a pos­si­bly non-​​deterministic mech­a­nism that com­putes a duplicate-​​free instance from $D$. The pos­si­ble results of this process are the clean, “min­i­mally resolved instances” (MRIs). There might be sev­eral MRIs for $D$, and the “resolved answers” to a query are those that are shared by all the MRIs. We inves­ti­gate the prob­lem of com­put­ing resolved answers. We look at var­i­ous sets of MDs, devel­op­ing syn­tac­tic cri­te­ria for deter­min­ing (in)tractability of the resolved answer prob­lem, includ­ing a dichotomy result. For some tractable classes of MDs and con­junc­tive queries, we present a query rewrit­ing method­ol­ogy that can be used to retrieve the resolved answers. We also inves­ti­gate con­nec­tions with “con­sis­tent query answer­ing”, deriv­ing fur­ther tractabil­ity results for MD-​​based ER.

    data­bases graph-​​theory algo­rithms nudge-​​targets
  • The Wash­room Game by Jan Heufer :: SSRN

    This arti­cle analy­ses a game where play­ers sequen­tially choose either to become insid­ers and pick one of finitely many loca­tions or to remain out­siders. They will only become insid­ers if a min­i­mum dis­tance to the next player can be assured; their sec­ondary objec­tive is to max­i­mize the min­i­mal dis­tance to other play­ers. This is illus­trated by con­sid­er­ing the strate­gic behav­ior of men choos­ing from a set of uri­nals in a pub­lic lava­tory. How­ever, besides very sim­i­lar sit­u­a­tions (e.g. set­tling of res­i­dents in a newly devel­oped area, the selec­tion of food patches by for­ag­ing ani­mals, choos­ing seats in wait­ing rooms or lines in a swim­ming pool), the game might also rel­e­vant to the prob­lem of plac­ing bill­boards attempt­ing to catch the atten­tion of passers-​​by or sim­i­lar eco­nomic sit­u­a­tions. In the non-​​cooperative equi­lib­rium, all insid­ers behave as if they coop­er­ated with each other and min­i­mized the total num­ber of insid­ers. It is shown that strate­gic behav­ior leads to an equi­lib­rium with sub­stan­tial under uti­liza­tion of avail­able loca­tions. Increas­ing the num­ber of loca­tions tends to decrease uti­liza­tion. The removal of some loca­tions which leads to gaps can not only increase rel­a­tive uti­liza­tion but even absolute max­i­mum capacity.

    game-​​theory agent-​​based com­plex­ol­ogy eco­nom­ics nudge-​​targets
  • [1109.0777] Effi­cient and Cor­rect Sten­cil Com­pu­ta­tion via Pat­tern Match­ing and Sta­tic Typing

    Sten­cil com­pu­ta­tions, involv­ing oper­a­tions over the ele­ments of an array, are a com­mon pro­gram­ming pat­tern in sci­en­tific com­put­ing, games, and image pro­cess­ing. As a pro­gram­ming pat­tern, sten­cil com­pu­ta­tions are highly reg­u­lar and amenable to opti­mi­sa­tion and par­al­leli­sa­tion. How­ever, general-​​purpose lan­guages obscure this reg­u­lar pat­tern from the com­piler, and even the pro­gram­mer, pre­vent­ing opti­mi­sa­tion and obfus­cat­ing (in)correctness. This paper fur­thers our work on the Ypnos domain-​​specific lan­guage for sten­cil com­pu­ta­tions embed­ded in Haskell. Ypnos allows declar­a­tive, abstract spec­i­fi­ca­tion of sten­cil com­pu­ta­tions, expos­ing the struc­ture of a prob­lem to the com­piler and to the pro­gram­mer via spe­cialised syn­tax. In this paper we show the decid­able safety guar­an­tee that well-​​formed, well-​​typed Ypnos pro­grams can­not index out­side of array bound­aries. Thus index­ing in Ypnos is safe and run-​​time bounds check­ing can be elim­i­nated. Pro­gram infor­ma­tion is encoded as types, using the advanced type-​​system fea­tures of the Glas­gow Haskell Com­piler, with the safe-​​indexing invari­ant enforced at com­pile time via type checking.

    domain-​​specific-​​language algo­rithms grid-​​computing nudge-​​targets
  • What’s Chal­leng­ing About Paul? : Lawyers, Guns & Money

    It’s wrong to think of Ron Paul’s racism and his lib­er­tar­i­an­ism as two dis­tinct parts of his polit­i­cal per­sona, when in fact they are deeply tied together. White suprema­cists under­stand what Glenn, appar­ently, does not; the absence of Fed­eral author­ity makes it eas­ier for pri­vate actors and local gov­ern­ments to repress the civil and polit­i­cal rights of minori­ties. Paul’s lib­er­tar­i­an­ism emerged in a regional and cul­tural con­text that was deeply hos­tile to Fed­eral efforts at inte­gra­tion. The newslet­ters give strong indi­ca­tion that none of this is lost on Ron Paul. A notional Pres­i­dent Paul is just as likely to use the pow­ers of the office to gut Fed­eral enforce­ment of a wide range of civil lib­er­ties pro­tec­tions as he is to do any of the things that Glenn would like him to do.

    pol­i­tics lib­er­tar­i­an­ism racism con­ser­vatism pop­ulism