Government
BnB-ADOPT: An Asynchronous Branch-and-Bound DCOP Algorithm
Yeoh, W., Felner, A., Koenig, S.
Distributed constraint optimization (DCOP) problems are a popular way of formulating and solving agent-coordination problems. A DCOP problem is a problem where several agents coordinate their values such that the sum of the resulting constraint costs is minimal. It is often desirable to solve DCOP problems with memory-bounded and asynchronous algorithms. We introduce Branch-and-Bound ADOPT (BnB-ADOPT), a memory-bounded asynchronous DCOP search algorithm that uses the message-passing and communication framework of ADOPT (Modi, Shen, Tambe, & Yokoo, 2005), a well known memory-bounded asynchronous DCOP search algorithm, but changes the search strategy of ADOPT from best-first search to depth-first branch-and-bound search. Our experimental results show that BnB-ADOPT finds cost-minimal solutions up to one order of magnitude faster than ADOPT for a variety of large DCOP problems and is as fast as NCBB, a memory-bounded synchronous DCOP search algorithm, for most of these DCOP problems. Additionally, it is often desirable to find bounded-error solutions for DCOP problems within a reasonable amount of time since finding cost-minimal solutions is NP-hard. The existing bounded-error approximation mechanism allows users only to specify an absolute error bound on the solution cost but a relative error bound is often more intuitive. Thus, we present two new bounded-error approximation mechanisms that allow for relative error bounds and implement them on top of BnB-ADOPT.
Some distance bounds of branching processes and their diffusion limits
Kammerer, Niels B., Stummer, Wolfgang
We compute exact values respectively bounds of "distances" - in the sense of (transforms of) power divergences and relative entropy - between two discrete-time Galton-Watson branching processes with immigration GWI for which the offspring as well as the immigration is arbitrarily Poisson-distributed (leading to arbitrary type of criticality). Implications for asymptotic distinguishability behaviour in terms of contiguity and entire separation of the involved GWI are given, too. Furthermore, we determine the corresponding limit quantities for the context in which the two GWI converge to Feller-type branching diffusion processes, as the time-lags between observations tend to zero. Some applications to (static random environment like) Bayesian decision making and Neyman-Pearson testing are presented as well.
From Tweets to Polls: Linking Text Sentiment to Public Opinion Time Series
O' (Carnegie Mellon University) | Connor, Brendan (Carnegie Mellon University) | Balasubramanyan, Ramnath (Carnegie Mellon University) | Routledge, Bryan R. (Carnegie Mellon University) | Smith, Noah A.
We connect measures of public opinion measured from polls with sentiment measured from text. We analyze several surveys on consumer confidence and political opinion over the 2008 to 2009 period, and find they correlate to sentiment word frequencies in contempora- neous Twitter messages. While our results vary across datasets, in several cases the correlations are as high as 80%, and capture important large-scale trends. The re- sults highlight the potential of text streams as a substi- tute and supplement for traditional polling. consumer confidence and political opinion, and can also pre- dict future movements in the polls. We find that temporal smoothing is a critically important issue to support a suc- cessful model.
What’s Worthy of Comment? Content and Comment Volume in Political Blogs
Yano, Tae (Carnegie Mellon University) | Smith, Noah A. (Carnegie Mellon University)
In research on blog data, comments are often ignored, What makes a blog post noteworthy? One measure of the and it is easy to see why: comments are very noisy, full popularity or breadth of interest of a blog post is the extent of nonstandard grammar and spelling, usually unedited, often to which readers of the blog are inspired to leave comments cryptic and uninformative, at least to those outside the on the post. In this paper, we study the relationship between blog's community. A few studies have focused on information the text contents of a blog post and the volume of response in comments. Mishe and Glance (2006) showed the it will receive from blog readers. Modeling this relationship value of comments in characterizing the social repercussions has the potential to reveal the interests of a blog's readership of a post, including popularity and controversy. Their largescale community to its authors, readers, advertisers, and scientists user study correlated popularity and comment activity.
RealScape: Metropolitan Fixed Assets Change Judgment by Pixel-by-pixel Stereo Processing of Aerial Photographs
Koizumi, Hirokazu (NEC System Technologies, Ltd.) | Yagyu, Hiroyuki (NEC System Technologies, Ltd.) | Hashizume, Kazuaki (NEC System Technologies, Ltd.) | Kamiya, Toshiyuki (NEC System Technologies, Ltd.) | Kunieda, Kazuo (NEC Corporation) | Shimazu, Hideo (NEC System Technologies, Ltd.)
The Japanese fixed-property tax is imposed by municipalities on the owners of land, buildings, and depreciation assets (all hereinafter referred to as "fixed assets") on January 1 of every year by calculating the tax sum according to current asset values. This identification work is contracted out to survey companies. The identification of such en over a scale that can cover an actual area of 800 changes is entrusted to survey companies who hire by 600 meters or 500 by 600 meters (variable a large number of workers (figure 1, left). However, depending on the municipality), and every municipality reliance on human labor has led to problems has several hundred photographs that must detailed in the following paragraphs. Under these circumstances, the incentives for It takes about 10 hours to read and interpret a single the municipalities to overcome such challenges by photograph, and the average municipality automating or systematizing the photograph-reading must perform this work for several hundred photographs.
Semantics for Digital Engineering Archives Supporting Engineering Design Education
Regli, William C. (Drexel University) | Kopena, Joseph B. (Drexel University) | Grauer, Michael (Drexel University) | Simpson, Timothy W. (Penn State University) | Stone, Robert B. (Oregon State University) | Lewis, Kemper (University at Buffalo - SUNY) | Bohm, Matt R. (Oregon State University) | Wilkie, David (Drexel University) | Piecyk, Martin (Drexel University) | Osecki, Jordan (Drexel University)
This article introduces the challenge of digital preservation in the area of engineering design and manufacturing and presents a methodology to apply knowledge representation and semantic techniques to develop Digital Engineering Archives. This work is part of an ongoing, multiuniversity, effort to create cyber infrastructure-based engineering repositories for undergraduates (CIBER-U) to support engineering design education. The technical approach is to use knowledge representation techniques to create formal models of engineering data elements, workflows and processes. With these formal engineering knowledge and processes can be captured and preserved with some guarantee of long-term interpretability. The article presents examples of how the techniques can be used to encode specific engineering information packages and workflows. These techniques are being integrated into a semantic wiki that supports the CIBER-U engineering education activities across nine universities and involving over 3500 students since 2006.
Lessons Learned from Virtual Humans
Swartout, William (University of Southern California Institute for Creative Technologies)
Over the past decade, we have been engaged in an extensive research effort to build virtual humans and applications that use them. Building a virtual human might be considered the quintessential AI problem, because it brings together many of the key features, such as autonomy, natural communication, sophisticated reasoning and behavior, that distinguish AI systems. This paper describes major virtual human systems we have built and important lessons we have learned along the way.
Scalable Probabilistic Databases with Factor Graphs and MCMC
Wick, Michael, McCallum, Andrew, Miklau, Gerome
Probabilistic databases play a crucial role in the management and understanding of uncertain data. However, incorporating probabilities into the semantics of incomplete databases has posed many challenges, forcing systems to sacrifice modeling power, scalability, or restrict the class of relational algebra formula under which they are closed. We propose an alternative approach where the underlying relational database always represents a single world, and an external factor graph encodes a distribution over possible worlds; Markov chain Monte Carlo (MCMC) inference is then used to recover this uncertainty to a desired level of fidelity. Our approach allows the efficient evaluation of arbitrary queries over probabilistic databases with arbitrary dependencies expressed by graphical models with structure that changes during inference. MCMC sampling provides efficiency by hypothesizing {\em modifications} to possible worlds rather than generating entire worlds from scratch. Queries are then run over the portions of the world that change, avoiding the onerous cost of running full queries over each sampled world. A significant innovation of this work is the connection between MCMC sampling and materialized view maintenance techniques: we find empirically that using view maintenance techniques is several orders of magnitude faster than naively querying each sampled world. We also demonstrate our system's ability to answer relational queries with aggregation, and demonstrate additional scalability through the use of parallelization.
Computing Inconsistency Measurements under Multi-Valued Semantics by Partial Max-SAT Solvers
Xiao, Guohui (Institute of Information Systems, Vienna University of Technology) | Lin, Zuoquan (Department of Information Science, Peking University) | Ma, Yue (Laboratoire d’Informatique de l’universit´e Paris-Nord, Université Paris Nord) | Qi, Guilin (School of Computer Science and Engineering, Southeast University)
Measuring the inconsistency degree of a knowledge base can help us to deal with inconsistencies. Several inconsistency measures have been given under different multi-valued semantics, including 4-valued semantics, 3-valued semantics, LPm and Quasi Classical semantics. In this paper, we first carefully analyze the relationship between these inconsistency measures by showing that the inconsistency degrees under 4-valued semantics, 3-value semantics, LPm are the same, but different from the one based on Quasi Classical semantics. We then consider the computation of these inconsistency measures and show that computing inconsistency measurement under multi-valued semantics is usually intractable. To tackle this problem, we propose two novel algorithms that respectively encode the problems of computing inconsistency degrees under 4-valued semantics (3-valued semantics, LPm) and under Quasi Classical semantics into the partial Max-SAT problems. We implement these algorithms and do experiments on some benchmark data sets. The preliminary but encouraging experimental results show that our approach is efficient to handle large knowledge bases.