These are my recent Pinboard.in links:

• [1106.1804] A Critical Assessment of Benchmark Comparison in Planning

  "Recent trends in planning research have led to empirical comparison becoming commonplace. The field has started to settle into a methodology for such comparisons, which for obvious practical reasons requires running a subset of planners on a subset of problems. In this paper, we characterize the methodology and examine eight implicit assumptions about the problems, planners and metrics used in many of these comparisons. The problem assumptions are: PR1) the performance of a general purpose planner should not be penalized/biased if executed on a sampling of problems and domains, PR2) minor syntactic differences in representation do not affect performance, and PR3) problems should be solvable by STRIPS capable planners unless they require ADL. The planner assumptions are: PL1) the latest version of a planner is the best one to use, PL2) default parameter settings approximate good performance, and PL3) time cut-offs do not unduly bias outcome. The metrics assumptions are: M1) performance degrades similarly for each planner when run on degraded runtime environments (e.g., machine platform) and M2) the number of plan steps distinguishes performance. We find that most of these assumptions are not supported empirically; in particular, that planners are affected differently by these assumptions. We conclude with a call to the community to devote research resources to improving the state of the practice and especially to enhancing the available benchmark problems."

  planning benchmarking algorithms horse-races engineering-design operations-research nudge-targets

• [1108.4361] The relationship between acquaintanceship and coauthorship in scientific collaboration networks

  "This article examines the relationship between acquaintanceship and coauthorship patterns in a multi-disciplinary, multi-institutional, geographically distributed research center. Two social networks are constructed and compared: a network of coauthorship, representing how researchers write articles with one another, and a network of acquaintanceship, representing how those researchers know each other on a personal level, based on their responses to an online survey. Statistical analyses of the topology and community structure of these networks point to the importance of small-scale, local, personal networks predicated upon acquaintanceship for accomplishing collaborative work in scientific communities."

  academic-culture network-theory citation social-networks

• [1108.4223] The set-theoretic multiverse

  "The multiverse view in set theory, introduced and argued for in this article, is the view that there are many distinct concepts of set, each instantiated in a corresponding set-theoretic universe. The universe view, in contrast, asserts that there is an absolute background set concept, with a corresponding absolute set-theoretic universe in which every set-theoretic question has a definite answer. The multiverse position, I argue, explains our experience with the enormous diversity of set-theoretic possibilities, a phenomenon that challenges the universe view. In particular, I argue that the continuum hypothesis is settled on the multiverse view by our extensive knowledge about how it behaves in the multiverse, and as a result it can no longer be settled in the manner formerly hoped for."

  mathematics mathematical-criticism looking-forward-to-understanding-this-someday pragmatism-it-ain't

• [1102.1934] The structure of the Arts & Humanities Citation Index: A mapping on the basis of aggregated citations among 1,157 journals

  "Using the Arts & Humanities Citation Index (A&HCI) 2008, we apply mapping techniques previously developed for mapping journal structures in the Science and Social Science Citation Indices. Citation relations among the 110,718 records were aggregated at the level of 1,157 journals specific to the A&HCI, and the journal structures are questioned on whether a cognitive structure can be reconstructed and visualized. Both cosine-normalization (bottom up) and factor analysis (top down) suggest a division into approximately twelve subsets. The relations among these subsets are explored using various visualization techniques. However, we were not able to retrieve this structure using the ISI Subject Categories, including the 25 categories which are specific to the A&HCI. We discuss options for validation such as against the categories of the Humanities Indicators of the American Academy of Arts and Sciences, the panel structure of the European Reference Index for the Humanities (ERIH), and compare our results with the curriculum organization of the Humanities Section of the College of Letters and Sciences of UCLA as an example of institutional organization."

  network-theory citation-networks humanities academic-culture quantitative-humanities

• [1108.4220] A Dynamical Systems Approach for Static Evaluation in Go

  "In the paper arguments are given why the concept of static evaluation has the potential to be a useful extension to Monte Carlo tree search. A new concept of modeling static evaluation through a dynamical system is introduced and strengths and weaknesses are discussed. The general suitability of this approach is demonstrated."

  representation-theory planning monte-carlo-models nudge algorithms

• [1105.5449] AntNet: Distributed Stigmergetic Control for Communications Networks

  "…We compare our algorithm with six state-of-the-art routing algorithms coming from the telecommunications and machine learning fields. The algorithms' performance is evaluated over a set of realistic testbeds. We run many experiments over real and artificial IP datagram networks with increasing number of nodes and under several paradigmatic spatial and temporal traffic distributions. Results are very encouraging. AntNet showed superior performance under all the experimental conditions with respect to its competitors. We analyze the main characteristics of the algorithm and try to explain the reasons for its superiority."

  ant-colony-optimization network-theory networks control algorithms nudge-targets routing

• Bozo Sapiens: Sacco and Vanzetti: Evidence

  "Wigmore’s technique, like probability itself, is both wide-ranging and tediously painstaking; his book was popular only among insomniac judges. But now that computers can take on the numerical drudgery, it is proving its worth in just such tangled cases as Sacco’s and Vanzetti’s. The legal scholars Joseph Kadane and David Schum have applied a sophisticated extension of Wigmore’s method to the vast body of evidence from the case. Theirs is a remarkable achievement; their charts retain all the original complexities: the facts withheld or perverted, the hearsay, the lies told and disavowed on both sides, the charged political atmosphere of eighty years ago. They never discount a fact, no matter how far-fetched; they  simply give it its due weight in their dynamic structure.

  Their conclusion?  Unjust though it is to summarize a book in a sentence, the balance of probability seems to favor the view expressed long ago by one of the defendants’ close companions: “everyone in the Boston anarchistic circle knew that Sacco was guilty and that Vanzetti was innocent as far as the actual participation in the killing.” So, there it is: whichever side our political instincts favor, we are destined to be half wrong.

  Vanzetti’s last words were: "I wish to forgive some people for what they are now doing to me."  If we were all willing to make the extra effort to work out the probabilities, perhaps we might not need forgiveness so often."

  probability-theory legal-studies computational-methods history

• Getting first sale wrong

  "I hate to imagine it, but this decision raises some frightening possibilities and requires greater vigilance on the part of librarians.  At the very least, libraries must demand information from publishers about where every item has been manufactured. Obtaining such information is no longer an option, since our legal uses of the things we buy now depends on knowing this, and the place where the publisher is located or where the sale took place is simply not sufficient.  But what I really fear is that publishers will begin to manufacture more of their works overseas and then try to demand a higher price – one that includes “public lending rights” – from libraries.

  If libraries are in a difficult position, students may be even worse off under the Second Circuit’s ruling.  Again, publishers now have an incentive to manufacture their textbooks abroad and sell them to U.S. students.  Such students would no longer have the right to re-sell their textbooks or to purchase used texts.  The defendant in the case, Supap Kirtsaeng, had made a lucrative business out of reselling textbooks purchased in Asia.  He was perhaps an unsympathetic party, but what he was doing was not different in kind from the resale of texts that is common on all college campuses.  This activity makes higher education a little more possible for many.  Now publishers have an easy way for to close down this secondary market for textbooks, about which they have complained for years.  In the process, the cost of education for college students would be pushed up even further."

  copyright insanity intellectual-property academic-culture librarians

• [1106.6037] Black Hole Search with Finite Automata Scattered in a Synchronous Torus

  "We consider the problem of locating a black hole in synchronous anonymous networks using finite state agents. A black hole is a harmful node in the network that destroys any agent visiting that node without leaving any trace. The objective is to locate the black hole without destroying too many agents. This is difficult to achieve when the agents are initially scattered in the network and are unaware of the location of each other. Previous studies for black hole search used more powerful models where the agents had non-constant memory, were labelled with distinct identifiers and could either write messages on the nodes of the network or mark the edges of the network. In contrast, we solve the problem using a small team of finite-state agents each carrying a constant number of identical tokens that could be placed on the nodes of the network. Thus, all resources used in our algorithms are independent of the network size. We restrict our attention to oriented torus networks and first show that no finite team of finite state agents can solve the problem in such networks, when the tokens are not movable. In case the agents are equipped with movable tokens, we determine lower bounds on the number of agents and tokens required for solving the problem in torus networks of arbitrary size. Further, we present a deterministic solution to the black hole search problem for oriented torus networks, using the minimum number of agents and tokens."

  algorithms agent-based multi-agent-systems network-theory nudge-targets

• [1106.1821] Collective Intelligence, Data Routing and Braess’ Paradox

  "We consider the problem of designing the the utility functions of the utility-maximizing agents in a multi-agent system so that they work synergistically to maximize a global utility. The particular problem domain we explore is the control of network routing by placing agents on all the routers in the network. Conventional approaches to this task have the agents all use the Ideal Shortest Path routing Algorithm (ISPA). We demonstrate that in many cases, due to the side-effects of one agent's actions on another agent's performance, having agents use ISPA's is suboptimal as far as global aggregate cost is concerned, even when they are only used to route infinitesimally small amounts of traffic. The utility functions of the individual agents are not "aligned" with the global utility, intuitively speaking. As a particular example of this we present an instance of Braess' paradox in which adding new links to a network whose agents all use the ISPA results in a decrease in overall throughput. We also demonstrate that load-balancing, in which the agents' decisions are collectively made to optimize the global cost incurred by all traffic currently being routed, is suboptimal as far as global cost averaged across time is concerned. This is also due to 'side-effects', in this case of current routing decision on future traffic. The mathematics of Collective Intelligence (COIN) is concerned precisely with the issue of avoiding such deleterious side-effects in multi-agent systems, both over time and space. We present key concepts from that mathematics and use them to derive an algorithm whose ideal version should have better performance than that of having all agents use the ISPA, even in the infinitesimal limit. We present experiments verifying this, and also showing that a machine-learning-based version of this COIN algorithm in which costs are only imprecisely estimated via empirical means (a version potentially applicable in the real world) also outperforms the ISPA, despite having access to less information than does the ISPA. In particular, this COIN algorithm almost always avoids Braess' paradox."

  collective-intelligence search-algorithms figure-ground-error planning nudge

• [1108.0404] Exploiting Agent and Type Independence in Collaborative Graphical Bayesian Games

  "Efficient collaborative decision making is an important challenge for multiagent systems. Finding optimal joint actions is especially challenging when each agent has only imperfect information about the state of its environment. Such problems can be modeled as collaborative Bayesian games in which each agent receives private information in the form of its type. However, representing and solving such games requires space and computation time exponential in the number of agents. This article introduces collaborative graphical Bayesian games (CGBGs), which facilitate more efficient collaborative decision making by decomposing the global payoff function as the sum of local payoff functions that depend on only a few agents. We propose a framework for the efficient solution of CGBGs based on the insight that they posses two different types of independence, which we call agent independence and type independence. In particular, we present a factor graph representation that captures both forms of independence and thus enables efficient solutions. In addition, we show how this representation can provide leverage in sequential tasks by using it to construct a novel method for decentralized partially observable Markov decision processes. Experimental results in both random and benchmark tasks demonstrate the improved scalability of our methods compared to several existing alternatives."

  collaboration agent-based complex-systems emergent-design nudge-targets

• [1102.2837] Efficient Promotion Strategies in Hierarchical Organizations

  "The Peter principle has been recently investigated by means of an agent-based simulation and its validity has been numerically corroborated. It has been confirmed that, within certain conditions, it can really influence in a negative way the efficiency of a pyramidal organization adopting meritocratic promotions. It was also found that, in order to bypass these effects, alternative promotion strategies should be adopted, as for example a random selection choice. In this paper, within the same line of research, we study promotion strategies in a more realistic hierarchical and modular organization and we show the robustness of our previous results, extending their validity to a more general context. We discuss also why the adoption of these strategies could be useful for real organizations."

  organizational-behavior complexology complexological-amusements agent-based competence