bluuebunny/crossref_metadata_2025 huggingface dataset:
Joint measurements of optical parameters by irradiance scintillation and angle-of-arrival fluctuations
Authors: Gao Chao , Liang Haodong , Li Xiaofeng
Published: July 2018

A method for joint measuring the power law exponent and the structure constant of atmospheric turbulence is proposed and examined. The measurements are equivalent to solve the simultaneous equations formed by the irradiance scintillation index and the angle-of-arrival fluctuations variance, where the measured parameters are regarded as the unknowns. The measured error analysis is also presented. Based on our proposed method, the measured results accord with the daily trend of atmospheric turbulence.
Size and Shape Controlled Synthesis of Pd Nanocrystals
Authors: Zhang Jiawei , Li Huiqi , Jiang Zhiyuan , Xie Zhaoxiong
Published: July 2018

Palladium (Pd) has attracted substantial academic interest due to its remarkable properties and extensive applications in many industrial processes and commercial devices. The development of Pd nanocrystals (NCs) would contribute to reduce overall precious metal loadings, and allow the efficient utilization of energy at lower economic costs. Furthermore, some of the important properties of Pd NCs can be substantially enhanced by rational designing and tight controlling of both size and shape. In this review, we have summarized the state-of-the-art research progress in the shape and size-controlled synthesis of noble-metal Pd NCs, which is based on the wet-chemical synthesis. Pd NCs have been categorized into five types: (1) single-crystalline Pd nano-polyhedra with well-defined low-index facets (e.g. {100}, {111} and {110}); (2) single-crystalline Pd nano polyhedra with well-defined high-index facets, such as Pd tetrahexahedra with {hk0} facets; (3) Pd NCs with cyclic penta-twinned structure, including icosahedra and decahedra; (4) monodisperse spherical Pd nanoparticles; (5) typical anisotropic Pd NCs, such as nanoframes, nanoplate, nanorods/wires. The synthetic approach and growth mechanisms of these types of Pd NCs are highlighted. The key factors that control the structures, including shapes (surface structures), twin structures, single-crystal nanostructures, and sizes are carefully elucidated. We also introduce the detailed characterization tools for analysis of Pd NCs with a specific type. The challenges faced and perspectives on this promising field are also briefly discussed. We believe that the detailed studies on the growth mechanisms of NCs provide a powerful guideline to the rational design and synthesis of noble-metal NCs with enhanced properties.

Graphical Abstract:
Magnetic resonance spectroscopy approaches for electrochemical research
Authors: Vyalikh Anastasia , Köhler Thomas , Zakharchenko Tatiana , Itkis Daniil M. , Krajnc Andraž , Mali Gregor
Published: July 2018

In this review paper, we provide a short overview of the application of magnetic resonance techniques in electrochemical studies. Brief theoretical descriptions, sensitivity aspects, challenges and new opportunities of nuclear magnetic resonance and electron paramagnetic resonance have been presented here. Particular attention will be paid to the studies using ex situ and in situ methodologies and their combination to address the questions concerning the intrinsic structures and the structural transformations, ionic mobility and interfacial interactions in the energy storage and energy conversion systems. In addition, theoretical approaches to support the experimental NMR observables as well as magnetic resonance imaging have been discussed in the context of improving electrochemical performance, cycling stability and safety of batteries.
X-ray photoelectron spectroscopy study of the interaction of lithium with graphene
Authors: Bulusheva Lyubov G. , Okotrub Alexander V. , Yashina Lada V. , Velasco-Velez Juan J. , Usachov Dmitry Yu. , Vyalikh Denis V.
Published: July 2018

Graphene-like nanostructures, solely or in combination with redox active compounds, are an important component of battery electrodes. Design of effective electrode materials requires a deep understanding of electrochemical reactions occurring at graphene surfaces. The methods of X-ray photoelectron spectroscopy (XPS) are very helpful in such research, providing the composition of studied samples and electronic state of individual elements. In this chapter, we demonstrate advantages of XPS for monitoring of chemical vapor deposition graphene growth and lithium penetration under graphene layers, disclosing of interactions with metals and interface states.
Ein Staatsfonds, der eine soziale Dividende finanziert
Authors: Corneo Giacomo
Published: July 2018

Die Regierung eines Landes kann sich zum risikolosen Zins verschulden und in den Weltaktienmarkt investieren. Die Aktienerträge werden abzüglich der Finanzierungskosten an die Bürger des Landes in Form einer sozialen Dividende weitergegeben. Welche Effekte hat diese Politik auf die Wohlfahrt der Bürger? Der vorliegende Beitrag identifiziert in einem einfachen theoretischen Rahmen Bedingungen, unter denen eine solche Politik eine Pareto-Verbesserung hervorruft und argumentiert für deren Einführung in Deutschland.
Wet steam measurement techniques
Authors: Walker David , Barham Scott , Giddings Donald , Dimitrakis Georgios
Published: July 2018

In recent years a greater need for power station efficiency has become evident; improving turbine blade efficiency is one of the methods proposed. This efficiency depends upon the wetness of the steam that comes into contact with the blades of the low-pressure turbine stage in general and all turbines in nuclear power generation. Therefore, measurement of the moisture content of the steam in real time in conjunction with an accurate measure of steam velocity can give an overall mass flow re-entering the turbine, allowing for a feedback control. The system can rely on one technique that can measure suspended droplets and wall-bound liquid film, or a combination of techniques can operate together. This work gives a comprehensive review of the different techniques used to measure the moisture content including the liquid film and moisture content and techniques that can give measurements on both simultaneously. Each technique has its strengths and weaknesses, and they were analysed to see which technique works best overall and which techniques can be used together.
The unseen, the discouraged and the outcast: Expressivity and the foundations of social recognition
Authors: Taipale Joona
Published: July 2018

This article analyzes different pathologies of social affirmation and examines the grounds of social recognition from the point of view of the concept of expression. The red thread of the text is provided by Tove Jansson’s fictional works, and the focus will be on three cases in particular (the magic hat, the invisible girl and the figure of the Groke). The article sets out from the phenomenological distinction between the sensible expression, on the one hand, and the expressed content, on the other. By focusing on the three cases, the article distinguishes and analyses the fundamental structures of communal life and explicates different ways in which social affirmation can be one-sided or distorted.
Halina Karaś. Polskie gwary okolic Ignalina i Jeziorosów na Litwie w świetle frekwencji cech językowych. Warszawa: Zakład Graficzny Uniwersytetu Warszawskiego, 2017, stron 398. ISBN 978-83-65557-66-3
Authors: Rutkovska Kristina
Published: July 2018

[text in Polish]
Rectal Levothyroxine for the Treatment of Hypothyroidism: A Case Study
Authors: Ybarra Marina , dos Santos Tiago Jeronimo , Pinheiro Claudia Teixeira Cabido , Dichtchekenian Vaê , Damiani Durval
Published: July 2018

Transient hypothyroidism can present itself as clinically asymptomatic or with few symptoms. Early treatment with levothyroxine (L-T4) prevents complications related to this disorder. We report a case of a male infant with concomitant short bowel syndrome and transient hypothyroidism treated with rectal L-T4. A 4-month-and-10-day-old boy with previous gastroschisis underwent multiple surgical approaches for small bowel resection and developed short bowel syndrome. We suspected hypothyroidism because of jaundice (direct bilirubin up to 59 mg/dL), the absence of evacuation, oral diet intolerance, and intestinal dysmotility. Because of a thyrotropin level of 34.45 μIU/mL and a free thyroxine level of 0.64 ng/dL, the diagnosis was confirmed. Because fasting was demanding, we started the patient on rectal diluted L-T4. After 4 weeks, the patient had spontaneous peristalsis, improvement of jaundice (direct bilirubin: 4.6 mg/dL), and normalized free thyroxine and thyrotropin values. In the present case, the patient was diagnosed with hypothyroidism and was on absolute fasting. An alternative route of drug administration was warranted. We empirically prescribed rectal diluted L-T4 when intravenous and suppository L-T4 were not available. This method was proven to be safe and effective in improving the patient’s clinical and biochemical status. Rectal L-T4 is a possible alternative route of administration to treat hypothyroidism in patients who are unable to take the medication orally.
Profissionais liberais e Pós-Graduação: percepções e estratégias em relação à avaliação da CAPES
Authors: Volpato Gildo , Valle Ione Ribeiro , Bianchetti Lucídio
Published: July 2018

O objetivo do estudo foi compreender as percepções dos profissionais liberais, das áreas de ciência social aplicada, engenharias e saúde, vinculados a programas de pós-graduação, sobre a avaliação da CAPES. A pesquisa abrangeu 18 (dezoito) profissionais liberais que atuam, também, como professores pesquisadores em cinco universidades comunitárias catarinenses. Foi utilizada a entrevista semiestruturada e na análise foi considerado os princípios da hermenêutica e da dialética, em diálogo com a ótica sociológica de Pierre Bourdieu. As respostas dos participantes demonstraram que há três problemas a serem superados no modelo de avaliação da CAPES: muda as regras durante o jogo, ou seja, apresenta as regras para o quadriênio concluído e não antes de iniciá-lo; valorizam-se mais quantidade de produtos do que a qualidade; dá pouca importância à relevância da pesquisa. Os entrevistados explicitaram estratégias adotadas para manter a pontuação exigida na avaliação, destacando-se: trabalhar nos finais de semana, à noite e na madrugada; trabalhar em colaboração com orientandos e professores; aproveitar ao máximo os dados, diagnósticos e os contatos do campo profissional, dentre outras.
Estresse e qualidade de vida de profissionais bombeiros militares do município de Primavera do Leste – Mato Grosso
Authors: Batista Rogério Costa , Magalhães Ávilo ROBERTO , Barbosa Leite Diogo
Published: July 2018

Estudos recentes apontam que o ambiente de trabalho pode desencadear estresse, a partir das pressões sofridas durante as atividades executadas. Entre os profissionais bombeiros militares, o principal fator que contribui para o estresse envolve a pressão das responsabilidades. Esta investigação tem o objetivo de analisar o estresse e a qualidade de vida dos bombeiros militares lotados na 6ª CIBM do município de Primavera do Leste-MT. A pesquisa caracteriza-se como exploratória e descritiva, sendo entrevistados 81% da população total de bombeiros. O instrumento utilizado para a coleta constituiu-se de questionário com questões objetivas sobre os distúrbios do sono; do Inventário de Sintomas de Estresse para Adultos de Lipp (ISSL) e do Instrumento de Escala de Avaliação da Qualidade de Vida da OMS–WHOQOL-bref. Os principais resultados apontam para a insatisfação com a jornada de trabalho, aparecimento de moléstias relacionadas ao estresse e menor satisfação com domínio físico.
Estudo da distribuição ótima das unidades coletoras de materiais reciclados em São Bernardo do Campo – um mapa para o investidor social
Authors: Morais Diogo Martins Gonçalves , Frey Julia Hille , Savassa Lucas Pires
Published: July 2018

A reciclagem tem-se mostrado excelente oportunidade de novos empreendimentos, traduzindo-se em emprego e renda para diversos níveis sociais. Diante disso, o presente estudo tem o objetivo de mapear os potenciais pontos de oferta de resíduos sólidos e descobrir qual seria a melhor localização geográfica de São Bernardo do Campo para a implantação de unidades coletoras desses materiais reciclados. Os pontos de oferta em potencial obtidos neste estudo passaram a compor um modelo de distribuição em rede, representadas por um grafo, onde os “nós” do grafo representam a localização geográfica de cada um dos pontos e as “arestas” dos grafos as distâncias entre cada uma delas e um ponto estratégico, cujas coordenadas cartesianas constituíram as variáveis do modelo. Para a resolução do modelo, utilizou-se o algoritmo conhecido por Generalized Reduced Gradiente (GRG). Os resultados e metodologia utilizada nesta pesquisa são apresentados e podem subsidiar a tomada de decisão de investidores sociais.
O Valor do Trabalho Voluntário: um estudo sobre o valor do trabalho do voluntário da Associação Viva e Deixe Viver.
Authors: Cimino Valdir
Published: July 2018

Este artigo tem como objetivo principal analisar as pesquisas e estudos que a Associação Viva e Deixe Viver realizou sobre o trabalho que desenvolve e seus voluntários, traçando o perfil do voluntário que atua na Associação e o valor da hora trabalhada pelo voluntariado. Em especial, a delimitação do tema versa a respeito da valorização e valoração do trabalho voluntário profissional, sobretudo na melhoria das relações interpessoais na educação e saúde. Busca mensurar o trabalho voluntário, qualificando a hora trabalhada. Encontra também razões para libertar o trabalho voluntário da ação assistencialista, conduzindo-o a uma visão profissional, tendo em vista a sua construção do capital humano. Outro aspecto será rever o conceito do trabalho voluntário pela ótica do social, a partir do conceito abrangente da sustentabilidade pela ótica do social, demonstrando a necessidade do trabalho voluntário para o campo econômico do país. Este trabalho pioneiro da Associação Viva e Deixe Viver traz como resultado maior os indicadores na melhoria dos relacionamentos comunicacionais e de acolhimento entre os sujeitos que trabalham com a saúde; paciente, a família, os profissionais da saúde e educação, promovendo políticas públicas da humanização da saúde, brinquedoteca e classe hospitalar.
INFLUÊNCIA DAS MÍDIAS SOCIAIS NO COMPORTAMENTO DE COMPRA DE CONSUMIDORES FITNESS
Authors: Schmidt Alexssandro Augusto , Araujo Fabiana Augusta de , Finocchio Carolina Pauletto Spanhol , Rodrigues Wesley Osvaldo Pradella
Published: July 2018

O objetivo deste estudo foi verificar a influência das mídias sociais no comportamento de compra dos indivíduos que frequentam academias de ginástica, denominados consumidores fitness. A pesquisa foi realizada com 200 consumidores no município de Bonito/MS. Verificou-se que as mídias sociais são utilizadas na busca de informações relacionadas a nutrição, treinamento físico, esporte e moda. Além disso, 75% dos entrevistados, após buscarem informações, afirmaram adquirir algum produto, dentre os quais se destacaram as frutas, os suplementos alimentares e os alimentos integrais. Este estudo contribui com as discussões relacionadas a influência das mídias sociais no comportamento de compra dos consumidores e seus impactos nas cadeias agroalimentares.
RELATION OF ANTHROPOMETRIC INDEXES AND CORONARY HEART DISEASE
Authors: Shalnova S. A. , Deev A. D. , Muromtseva G. A. , Balanova J. A. , Imaeva A. E. , Kapustina A. V. , Evstifeeva S. E. , Shepel R. N. , Rotar O. P. , Nedogoda S. V. , Shabunova A. A. , Chernykh T. M. , Romanchuk S. V. , Indukaeva E. V. , Grinstein Y. I. , Libis R. A. , Duplyakov D. V. , Trubacheva I. A. , Efanov A. Y. , Tolparov G. V. , Kulakova N. V. , Shlyakhto E. V. , Boytsov S. A. , Drapkina O. M.
Published: July 2018

An epidemics of obesity in the world during recent two decades, has already led to increased prevalence of diabetes, metabolic syndrome, oncological diseases, etc. Obesity is assessed with a variety of indexes, and recently the number of such tools was added with the two additional: visceral obesity index (VOI) and index of lipid products deposition (ILPD). The aim of the study — evaluation of the relation of anthropometric parameters with coronary heart disease. Materials of the study were representative selections from 13 regions of the ESSE-RF trial. In analysis of associations of body mass index (BMI), waist circumference (WC), relation of WC to height (WC/height x 100), VOI and IPLD with correction on the age and region, it was found that all studied parameters are significantly correlated with ischemic heart disease, however when the main risk factors were added, only two remained — odds ratio (95% confidence interval) for: WC/height×100 — 1,030 (1,019;1,040) (р<0,0001) and VOI — 1,053 (1,020;1,087) (р<0,0015) in males and WC/height×100 — 1,027 (1,021;1,033) (р<0,0001) and VOI — 1,052 (1,022;1,083) (р<0,0007) in females. It is important to note almost identical values of odds ratio for the indexes in both sexes. Reliability of the models obtained is confirmed by ROC analysis, where the area under curve for males was 0,68 and for females 0,67. The results witness on legitimacy of search for novel parameters of obesity that would have good reproducibility and are also simple and easy to use.
Competitive Safety Analysis: Robust Decision-Making
in Multi-Agent Systems
Authors: Tennenholtz M.
Published: July 2018

Much work in AI deals with the selection of proper actions in a given (known or unknown) environment. However, the way to select a proper action when facing other agents is quite unclear. Most work in AI adopts classical game-theoretic equilibrium analysis to predict agent behavior in such settings. This approach however does not provide us with any guarantee for the agent. In this paper we introduce competitive safety analysis. This approach bridges the gap between the desired normative AI approach, where a strategy should be selected in order to guarantee a desired payoff, and equilibrium analysis. We show that a safety level strategy is able to guarantee the value obtained in a Nash equilibrium, in several classical computer science settings. Then, we discuss the concept of competitive safety strategies, and illustrate its use in a decentralized load balancing setting, typical to network problems. In particular, we show that when we have many agents, it is possible to guarantee an expected payoff which is a factor of 8/9 of the payoff obtained in a Nash equilibrium. Our discussion of competitive safety analysis for decentralized load balancing is further developed to deal with many communication links and arbitrary speeds. Finally, we discuss the extension of the above concepts to Bayesian games, and illustrate their use in a basic auctions setup.
A Unified Model of Structural Organization in Language and Music
Authors: Bod R.
Published: July 2018

Is there a general model that can predict the perceived phrase structure in language and music? While it is usually assumed that humans have separate faculties for language and music, this work focuses on the commonalities rather than on the differences between these modalities, aiming at finding a deeper 'faculty'. Our key idea is that the perceptual system strives for the simplest structure (the 'simplicity principle'), but in doing so it is biased by the likelihood of previous structures (the 'likelihood principle'). We present a series of data-oriented parsing (DOP) models that combine these two principles and that are tested on the Penn Treebank and the Essen Folksong Collection. Our experiments show that (1) a combination of the two principles outperforms the use of either of them, and (2) exactly the same model with the same parameter setting achieves maximum accuracy for both language and music. We argue that our results suggest an interesting parallel between linguistic and musical structuring.
Bound Propagation
Authors: Leisink M. , Kappen B.
Published: July 2018

In this article we present an algorithm to compute bounds on the marginals of a graphical model. For several small clusters of nodes upper and lower bounds on the marginal values are computed independently of the rest of the network. The range of allowed probability distributions over the surrounding nodes is restricted using earlier computed bounds. As we will show, this can be considered as a set of constraints in a linear programming problem of which the objective function is the marginal probability of the center nodes. In this way knowledge about the maginals of neighbouring clusters is passed to other clusters thereby tightening the bounds on their marginals. We show that sharp bounds can be obtained for undirected and directed graphs that are used for practical applications, but for which exact computations are infeasible.
Representing and Aggregating Conflicting Beliefs
Authors: Maynard-Zhang P. , Lehmann D.
Published: July 2018

We consider the two-fold problem of representing collective beliefs and aggregating these beliefs. We propose a novel representation for collective beliefs that uses modular, transitive relations over possible worlds. They allow us to represent conflicting opinions and they have a clear semantics, thus improving upon the quasi-transitive relations often used in social choice. We then describe a way to construct the belief state of an agent informed by a set of sources of varying degrees of reliability. This construction circumvents Arrow's Impossibility Theorem in a satisfactory manner by accounting for the explicitly encoded conflicts. We give a simple set-theory-based operator for combining the information of multiple agents. We show that this operator satisfies the desirable invariants of idempotence, commutativity, and associativity, and, thus, is well-behaved when iterated, and we describe a computationally effective way of computing the resulting belief state. Finally, we extend our framework to incorporate voting.
IDL-Expressions: A Formalism for Representing and Parsing Finite Languages in Natural Language Processing
Authors: Nederhof M. J. , Satta G.
Published: July 2018

We propose a formalism for representation of finite languages, referred to as the class of IDL-expressions, which combines concepts that were only considered in isolation in existing formalisms. The suggested applications are in natural language processing, more specifically in surface natural language generation and in machine translation, where a sentence is obtained by first generating a large set of candidate sentences, represented in a compact way, and then by filtering such a set through a parser. We study several formal properties of IDL-expressions and compare this new formalism with more standard ones. We also present a novel parsing algorithm for IDL-expressions and prove a non-trivial upper bound on its time complexity.
PHA*: Finding the Shortest Path with A* in An Unknown Physical Environment
Authors: Felner A. , Stern R. , Ben-Yair A. , Kraus S. , Netanyahu N.
Published: July 2018

We address the problem of finding the shortest path between two points in an unknown real physical environment, where a traveling agent must move around in the environment to explore unknown territory. We introduce the Physical-A* algorithm (PHA*) for solving this problem. PHA* expands all the mandatory nodes that A* would expand and returns the shortest path between the two points. However, due to the physical nature of the problem, the complexity of the algorithm is measured by the traveling effort of the moving agent and not by the number of generated nodes, as in standard A*. PHA* is presented as a two-level algorithm, such that its high level, A*, chooses the next node to be expanded and its low level directs the agent to that node in order to explore it. We present a number of variations for both the high-level and low-level procedures and evaluate their performance theoretically and experimentally. We show that the travel cost of our best variation is fairly close to the optimal travel cost, assuming that the mandatory nodes of A* are known in advance. We then generalize our algorithm to the multi-agent case, where a number of cooperative agents are designed to solve the problem. Specifically, we provide an experimental implementation for such a system. It should be noted that the problem addressed here is not a navigation problem, but rather a problem of finding the shortest path between two points for future usage.
Restricted Value Iteration: Theory and Algorithms
Authors: Zhang W. , Zhang N. L.
Published: July 2018

Value iteration is a popular algorithm for finding near optimal policies for POMDPs. It is inefficient due to the need to account for the entire belief space, which necessitates the solution of large numbers of linear programs. In this paper, we study value iteration restricted to belief subsets. We show that, together with properly chosen belief subsets, restricted value iteration yields near-optimal policies and we give a condition for determining whether a given belief subset would bring about savings in space and time. We also apply restricted value iteration to two interesting classes of POMDPs, namely informative POMDPs and near-discernible POMDPs.
Combining Knowledge- and Corpus-based Word-Sense-Disambiguation Methods
Authors: Montoyo A. , Suarez A. , Rigau G. , Palomar M.
Published: July 2018

In this paper we concentrate on the resolution of the lexical ambiguity that arises when a given word has several different meanings. This specific task is commonly referred to as word sense disambiguation (WSD). The task of WSD consists of assigning the correct sense to words using an electronic dictionary as the source of word definitions. We present two WSD methods based on two main methodological approaches in this research area: a knowledge-based method and a corpus-based method. Our hypothesis is that word-sense disambiguation requires several knowledge sources in order to solve the semantic ambiguity of the words. These sources can be of different kinds--- for example, syntagmatic, paradigmatic or statistical information. Our approach combines various sources of knowledge, through combinations of the two WSD methods mentioned above. Mainly, the paper concentrates on how to combine these methods and sources of information in order to achieve good results in the disambiguation. Finally, this paper presents a comprehensive study and experimental work on evaluation of the methods and their combinations.
Keys, Nominals, and Concrete Domains
Authors: Carsten L. , Areces C. , Horrocks I. , Sattler U.
Published: July 2018

Many description logics (DLs) combine knowledge representation on an abstract, logical level with an interface to 'concrete' domains like numbers and strings with built-in predicates such as >, +, and prefix-of. These hybrid DLs have turned out to be useful in several application areas, such as reasoning about conceptual database models. We propose to further extend such DLs with key constraints that allow the expression of statements like 'US citizens are uniquely identified by their social security number'. Based on this idea, we introduce a number of natural description logics and perform a detailed analysis of their decidability and computational complexity. It turns out that naive extensions with key constraints easily lead to undecidability, whereas more careful extensions yield NExpTime-complete DLs for a variety of useful concrete domains.
Logical Hidden Markov Models
Authors: Kersting K. , De Raedt L. , Raiko T.
Published: July 2018

Logical hidden Markov models (LOHMMs) upgrade traditional hidden Markov models to deal with sequences of structured symbols in the form of logical atoms, rather than flat characters.

This note formally introduces LOHMMs and presents solutions to the three central inference problems for LOHMMs: evaluation, most likely hidden state sequence and parameter estimation. The resulting representation and algorithms are experimentally evaluated on problems from the domain of bioinformatics.
Decision-Theoretic Planning with non-Markovian Rewards
Authors: Thiebaux S. , Gretton C. , Slaney J. , Price D. , Kabanza F.
Published: July 2018

A decision process in which rewards depend on history rather than merely on the current state is called a decision process with non-Markovian rewards (NMRDP). In decision-theoretic planning, where many desirable behaviours are more naturally expressed as properties of execution sequences rather than as properties of states, NMRDPs form a more natural model than the commonly adopted fully Markovian decision process (MDP) model. While the more tractable solution methods developed for MDPs do not directly apply in the presence of non-Markovian rewards, a number of solution methods for NMRDPs have been proposed in the literature. These all exploit a compact specification of the non-Markovian reward function in temporal logic, to automatically translate the NMRDP into an equivalent MDP which is solved using efficient MDP solution methods. This paper presents NMRDPP (Non-Markovian Reward Decision Process Planner), a software platform for the development and experimentation of methods for decision-theoretic planning with non-Markovian rewards. The current version of NMRDPP implements, under a single interface, a family of methods based on existing as well as new approaches which we describe in detail. These include dynamic programming, heuristic search, and structured methods. Using NMRDPP, we compare the methods and identify certain problem features that affect their performance. NMRDPP's treatment of non-Markovian rewards is inspired by the treatment of domain-specific search control knowledge in the TLPlan planner, which it incorporates as a special case. In the First International Probabilistic Planning Competition, NMRDPP was able to compete and perform well in both the domain-independent and hand-coded tracks, using search control knowledge in the latter.
The Deterministic Part of IPC-4: An Overview
Authors: Hoffmann J. , Edelkamp S.
Published: July 2018

We provide an overview of the organization and results of the deterministic part of the 4th International Planning Competition, i.e., of the part concerned with evaluating systems doing deterministic planning. IPC-4 attracted even more competing systems than its already large predecessors, and the competition event was revised in several important respects. After giving an introduction to the IPC, we briefly explain the main differences between the deterministic part of IPC-4 and its predecessors. We then introduce formally the language used, called PDDL2.2 that extends PDDL2.1 by derived predicates and timed initial literals. We list the competing systems and overview the results of the competition. The entire set of data is far too large to be presented in full. We provide a detailed summary; the complete data is available in an online appendix. We explain how we awarded the competition prizes.
Cooperative Information Sharing to Improve Distributed Learning in Multi-Agent Systems
Authors: Dutta P. S. , Jennings N. R. , Moreau L.
Published: July 2018

Effective coordination of agents' actions in partially-observable domains is a major challenge of multi-agent systems research. To address this, many researchers have developed techniques that allow the agents to make decisions based on estimates of the states and actions of other agents that are typically learnt using some form of machine learning algorithm. Nevertheless, many of these approaches fail to provide an actual means by which the necessary information is made available so that the estimates can be learnt. To this end, we argue that cooperative communication of state information between agents is one such mechanism. However, in a dynamically changing environment, the accuracy and timeliness of this communicated information determine the fidelity of the learned estimates and the usefulness of the actions taken based on these. Given this, we propose a novel information-sharing protocol, post-task-completion sharing, for the distribution of state information. We then show, through a formal analysis, the improvement in the quality of estimates produced using our strategy over the widely used protocol of sharing information between nearest neighbours. Moreover, communication heuristics designed around our information-sharing principle are subjected to empirical evaluation along with other benchmark strategies (including Littman's Q-routing and Stone's TPOT-RL) in a simulated call-routing application. These studies, conducted across a range of environmental settings, show that, compared to the different benchmarks used, our strategy generates an improvement of up to 60% in the call connection rate; of more than 1000% in the ability to connect long-distance calls; and incurs as low as 0.25 of the message overhead.
Fault Tolerant Boolean Satisfiability
Authors: Roy A.
Published: July 2018

A delta-model is a satisfying assignment of a Boolean formula for which any small alteration, such as a single bit flip, can be repaired by flips to some small number of other bits, yielding a new satisfying assignment. These satisfying assignments represent robust solutions to optimization problems (e.g., scheduling) where it is possible to recover from unforeseen events (e.g., a resource becoming unavailable). The concept of delta-models was introduced by Ginsberg, Parkes and Roy (AAAI 1998) , where it was proved that finding delta-models for general Boolean formulas is NP-complete. In this paper, we extend that result by studying the complexity of finding delta-models for classes of Boolean formulas which are known to have polynomial time satisfiability solvers. In particular, we examine 2-SAT, Horn-SAT, Affine-SAT, dual-Horn-SAT, 0-valid and 1-valid SAT. We see a wide variation in the complexity of finding delta-models, e.g., while 2-SAT and Affine-SAT have polynomial time tests for delta-models, testing whether a Horn-SAT formula has one is NP-complete.
Cognitive Principles in Robust Multimodal Interpretation
Authors: Chai J. Y. , Prasov Z. , Qu S.
Published: July 2018

Multimodal conversational interfaces provide a natural means for users to communicate with computer systems through multiple modalities such as speech and gesture. To build effective multimodal interfaces, automated interpretation of user multimodal inputs is important. Inspired by the previous investigation on cognitive status in multimodal human machine interaction, we have developed a greedy algorithm for interpreting user referring expressions (i.e., multimodal reference resolution). This algorithm incorporates the cognitive principles of Conversational Implicature and Givenness Hierarchy and applies constraints from various sources (e.g., temporal, semantic, and contextual) to resolve references. Our empirical results have shown the advantage of this algorithm in efficiently resolving a variety of user references. Because of its simplicity and generality, this approach has the potential to improve the robustness of multimodal input interpretation.
The Case for Durative Actions: A Commentary on PDDL2.1
Authors: Smith D. E.
Published: July 2018

The addition of durative actions to PDDL2.1 sparked some controversy. Fox and Long argued that actions should be considered as instantaneous, but can start and stop processes. Ultimately, a limited notion of durative actions was incorporated into the language. I argue that this notion is still impoverished, and that the underlying philosophical position of regarding durative actions as being a shorthand for a start action, process, and stop action ignores the realities of modelling and execution for complex systems.
Learning Sentence-internal Temporal Relations
Authors: Lapata M. , Lascarides A.
Published: July 2018

In this paper we propose a data intensive approach for inferring sentence-internal temporal relations. Temporal inference is relevant for practical NLP applications which either extract or synthesize temporal information (e.g., summarisation, question answering). Our method bypasses the need for manual coding by exploiting the presence of markers like ``after", which overtly signal a temporal relation. We first show that models trained on main and subordinate clauses connected with a temporal marker achieve good performance on a pseudo-disambiguation task simulating temporal inference (during testing the temporal marker is treated as unseen and the models must select the right marker from a set of possible candidates). Secondly, we assess whether the proposed approach holds promise for the semi-automatic creation of temporal annotations. Specifically, we use a model trained on noisy and approximate data (i.e., main and subordinate clauses) to predict intra-sentential relations present in TimeBank, a corpus annotated rich temporal information. Our experiments compare and contrast several probabilistic models differing in their feature space, linguistic assumptions and data requirements. We evaluate performance against gold standard corpora and also against human subjects.
Marvin: A Heuristic Search Planner with Online Macro-Action Learning
Authors: Coles A. I. , Smith A. J.
Published: July 2018

This paper describes Marvin, a planner that competed in the Fourth International Planning Competition (IPC 4). Marvin uses action-sequence-memoisation techniques to generate macro-actions, which are then used during search for a solution plan. We provide an overview of its architecture and search behaviour, detailing the algorithms used. We also empirically demonstrate the effectiveness of its features in various planning domains; in particular, the effects on performance due to the use of macro-actions, the novel features of its search behaviour, and the native support of ADL and Derived Predicates.
Solving Factored MDPs with Hybrid State and Action Variables
Authors: Kveton B. , Hauskrecht M. , Guestrin C.
Published: July 2018

Efficient representations and solutions for large decision problems with continuous and discrete variables are among the most important challenges faced by the designers of automated decision support systems. In this paper, we describe a novel hybrid factored Markov decision process (MDP) model that allows for a compact representation of these problems, and a new hybrid approximate linear programming (HALP) framework that permits their efficient solutions. The central idea of HALP is to approximate the optimal value function by a linear combination of basis functions and optimize its weights by linear programming. We analyze both theoretical and computational aspects of this approach, and demonstrate its scale-up potential on several hybrid optimization problems.
Combination Strategies for Semantic Role Labeling
Authors: Surdeanu M. , Marquez L. , Carreras X. , Comas P. R.
Published: July 2018

This paper introduces and analyzes a battery of inference models for the problem of semantic role labeling: one based on constraint satisfaction, and several strategies that model the inference as a meta-learning problem using discriminative classifiers. These classifiers are developed with a rich set of novel features that encode proposition and sentence-level information. To our knowledge, this is the first work that: (a) performs a thorough analysis of learning-based inference models for semantic role labeling, and (b) compares several inference strategies in this context. We evaluate the proposed inference strategies in the framework of the CoNLL-2005 shared task using only automatically-generated syntactic information. The extensive experimental evaluation and analysis indicates that all the proposed inference strategies are successful -they all outperform the current best results reported in the CoNLL-2005 evaluation exercise- but each of the proposed approaches has its advantages and disadvantages. Several important traits of a state-of-the-art SRL combination strategy emerge from this analysis: (i) individual models should be combined at the granularity of candidate arguments rather than at the granularity of complete solutions; (ii) the best combination strategy uses an inference model based in learning; and (iii) the learning-based inference benefits from max-margin classifiers and global feedback.
Cutset Sampling for Bayesian Networks
Authors: Bidyuk B. , Dechter R.
Published: July 2018

The paper presents a new sampling methodology for Bayesian networks that samples only a subset of variables and applies exact inference to the rest. Cutset sampling is a network structure-exploiting application of the Rao-Blackwellisation principle to sampling in Bayesian networks. It improves convergence by exploiting memory-based inference algorithms. It can also be viewed as an anytime approximation of the exact cutset-conditioning algorithm developed by Pearl. Cutset sampling can be implemented efficiently when the sampled variables constitute a loop-cutset of the Bayesian network and, more generally, when the induced width of the network's graph conditioned on the observed sampled variables is bounded by a constant w. We demonstrate empirically the benefit of this scheme on a range of benchmarks.
The Generalized A* Architecture
Authors: Felzenszwalb P. F. , McAllester D.
Published: July 2018

We consider the problem of computing a lightest derivation of a global structure using a set of weighted rules. A large variety of inference problems in AI can be formulated in this framework. We generalize A* search and heuristics derived from abstractions to a broad class of lightest derivation problems. We also describe a new algorithm that searches for lightest derivations using a hierarchy of abstractions. Our generalization of A* gives a new algorithm for searching AND/OR graphs in a bottom-up fashion.

We discuss how the algorithms described here provide a general architecture for addressing the pipeline problem --- the problem of passing information back and forth between various stages of processing in a perceptual system. We consider examples in computer vision and natural language processing. We apply the hierarchical search algorithm to the problem of estimating the boundaries of convex objects in grayscale images and compare it to other search methods. A second set of experiments demonstrate the use of a new compositional model for finding salient curves in images.
Topic and Role Discovery in Social Networks with Experiments on Enron and Academic Email
Authors: McCallum A. , Wang X. , Corrada-Emmanuel A.
Published: July 2018

Previous work in social network analysis (SNA) has modeled the existence of links from one entity to another, but not the attributes such as language content or topics on those links. We present the Author-Recipient-Topic (ART) model for social network analysis, which learns topic distributions based on the direction-sensitive messages sent between entities. The model builds on Latent Dirichlet Allocation (LDA) and the Author-Topic (AT) model, adding the key attribute that distribution over topics is conditioned distinctly on both the sender and recipient---steering the discovery of topics according to the relationships between people. We give results on both the Enron email corpus and a researcher's email archive, providing evidence not only that clearly relevant topics are discovered, but that the ART model better predicts people's roles and gives lower perplexity on previously unseen messages. We also present the Role-Author-Recipient-Topic (RART) model, an extension to ART that explicitly represents people's roles.
Sound and Complete Inference Rules for SE-Consequence
Authors: Wong K.
Published: July 2018

The notion of strong equivalence on logic programs with answer set semantics gives rise to a consequence relation on logic program rules, called SE-consequence. We present a sound and complete set of inference rules for SE-consequence on disjunctive logic programs.
On the Value of Correlation
Authors: Ashlagi I. , Monderer D. , Tennenholtz M.
Published: July 2018

Correlated equilibrium generalizes Nash equilibrium to allow correlation devices. Correlated equilibrium captures the idea that in many systems there exists a trusted administrator who can recommend behavior to a set of agents, but can not enforce such behavior. This makes this solution concept most appropriate to the study of multi-agent systems in AI. Aumann showed an example of a game, and of a correlated equilibrium in this game in which the agents' welfare (expected sum of players' utilities) is greater than their welfare in all mixed-strategy equilibria. Following the idea initiated by the price of anarchy literature this suggests the study of two major measures for the value of correlation in a game with nonnegative payoffs:

1. The ratio between the maximal welfare obtained in a correlated equilibrium to the maximal welfare obtained in a mixed-strategy equilibrium. We refer to this ratio as the mediation value.

2. The ratio between the maximal welfare to the maximal welfare obtained in a correlated equilibrium. We refer to this ratio as the enforcement value.

In this work we initiate the study of the mediation and enforcement values, providing several general results on the value of correlation as captured by these concepts. We also present a set of results for the more specialized case of congestion games, a class of games that received a lot of attention in the recent literature.
An Ordinal Bargaining Solution with Fixed-Point Property
Authors: Zhang D. , Zhang Y.
Published: July 2018

Shapley's impossibility result indicates that the two-person bargaining problem has no non-trivial ordinal solution with the traditional game-theoretic bargaining model. Although the result is no longer true for bargaining problems with more than two agents, none of the well known bargaining solutions are ordinal. Searching for meaningful ordinal solutions, especially for the bilateral bargaining problem, has been a challenging issue in bargaining theory for more than three decades. This paper proposes a logic-based ordinal solution to the bilateral bargaining problem. We argue that if a bargaining problem is modeled in terms of the logical relation of players' physical negotiation items, a meaningful bargaining solution can be constructed based on the ordinal structure of bargainers' preferences. We represent bargainers' demands in propositional logic and bargainers' preferences over their demands in total preorder. We show that the solution satisfies most desirable logical properties, such as individual rationality (logical version), consistency, collective rationality as well as a few typical game-theoretic properties, such as weak Pareto optimality and contraction invariance. In addition, if all players' demand sets are logically closed, the solution satisfies a fixed-point condition, which says that the outcome of a negotiation is the result of mutual belief revision. Finally, we define various decision problems in relation to our bargaining model and study their computational complexity.
Modeling Belief in Dynamic Systems, Part II: Revision and Update
Authors: Friedman N. , Halpern J. Y.
Published: July 2018

The study of belief change has been an active area in philosophy and AI. In recent years two special cases of belief change, belief revision and belief update, have been studied in detail. In a companion paper (Friedman & Halpern, 1997), we introduce a new framework to model belief change. This framework combines temporal and epistemic modalities with a notion of plausibility, allowing us to examine the change of beliefs over time. In this paper, we show how belief revision and belief update can be captured in our framework. This allows us to compare the assumptions made by each method, and to better understand the principles underlying them. In particular, it shows that Katsuno and Mendelzon's notion of belief update (Katsuno & Mendelzon, 1991a) depends on several strong assumptions that may limit its applicability in artificial intelligence. Finally, our analysis allow us to identify a notion of minimal change that underlies a broad range of belief change operations including revision and update.