bluuebunny/crossref_metadata_2025 huggingface dataset:
Visual and Hearing Impairments After Preterm Birth
Authors: Hirvonen Mikko , Ojala Riitta , Korhonen Päivi , Haataja Paula , Eriksson Kai , Gissler Mika , Luukkaala Tiina , Tammela Outi
Published: July 2018

OBJECTIVES:

Our aim was to determine and compare the incidences of sensory impairments among very preterm (VP) (<32 + 0/7 weeks), moderately preterm (MP) (32 + 0/7–33 + 6/7 weeks), late preterm (LP) (34 + 0/7–36 + 6/7 weeks), and term infants (≥37 weeks) and to establish risk factors of neurosensory disabilities.

METHODS:

This national register study included all live-born infants in Finland between 1991 and 2008. Infants who died before the age of 1 year, who had any major congenital anomaly, or had missing data were excluded (n = 21 007; 2.0%). A total of 1 018 256 infants were analyzed. Incidences of hearing loss, visual disturbances or blindness, other ophthalmologic disorders, and retinopathy of prematurity were determined for gestational age (GA) groups. Risk factors of hearing loss and visual disturbances or blindness were analyzed.

RESULTS:

The incidences of sensory impairments decreased with advancing GA at birth (P < .001). The most prominent factors associated with increased risks of hearing loss and visual impairment were intracranial hemorrhage and convulsions. VP (odds ratio [OR] 2.34; 95% confidence interval [CI] 1.75–3.14) and LP (OR 1.26; 95% CI 1.04–1.52) births were associated with an increased risk of hearing loss, and VP (OR 1.94; 95% CI 1.55–2.44), MP (OR 1.42; 95% CI 1.11–1.80), and LP (OR 1.31; 95% CI 1.16–1.49) births predicted an increased risk of visual impairment.

CONCLUSIONS:

Incidences of sensory impairment decreased with increasing GA at birth. The most prominent risk factors predictive of sensory disabilities were intracranial hemorrhage and convulsions. VP and LP births were associated with an increased risk of hearing loss, and VP, MP, and LP births were associated with an increased risk of visual impairment.
Concepções e práticas acerca da formação continuada e o papel da gestão escolar: narrativas de professoras
Authors: Bastos Marilia Salles , Santos Luciana Dalla Nora dos
Published: July 2018

Neste artigo, apresentam-se as discussões resultantes da pesquisa “Concepções e práticas acerca da formação continuada e o papel da gestão: narrativas de professoras”, que teve como foco compreender as concepções de professoras sobre formação continuada e sobre o modo como a gestão encaminha essas atividades. Tendo um papel significativo ao mediar o planejamento e a participação dos professores, a gestão busca coletivamente a compreensão sobre a importância dessas práticas para o trabalho docente. Defende-se o espaço da escola como o mais rico para essas atividades, partindo das experiências e das vivências das professoras. Freire (1996), Marcelo Garcia (1999), Bolzan (2002), Nóvoa (2009), Vaillant, Marcelo Garcia (2012) e Libâneo (2013) são alguns dos autores base. A metodologia utilizada é qualitativa, com abordagem narrativa sociocultural e entrevistas narrativas semiestruturadas com professoras da rede municipal de educação do município de Júlio de Castilhos. Essas narrativas permitiram construir as dimensões categoriais concepções e práticas de formação e papel da gestão, que expressam a formação continuada como atividade prevista e planejada pela gestão. Porém não tendo ainda sua importância e suas implicações para o trabalho na escola incorporadas pelos docentes e pela gestão quando se refere à maneira como é enfrentada. A oferta dessas atividades advém significativamente do cumprimento de planejamento/cronograma de gestão, e, a partir deste, as professoras buscam “aproveitarse” de algo que seja satisfatório para o trabalho docente. Assim, destaca-se o papel da gestão ao possibilitar e considerar espaços para escuta, reflexão e compartilhamento de experiências como base para o planejamento.
La transnacionalización de ideas: la escuela contrasubversiva de Argentina a Guatemala
Authors: Rostica Julieta Carla
Published: July 2018

El artículo tiene por objetivo demostrar el flujo y la recepción de ideas relativas a la seguridad nacional desde Argentina hacia Guatemala, como una forma más de transnacionalización del terrorismo de Estado en América Latina y abonar otro ejemplo más de la colaboración argentina en la lucha contrasubversiva de Guatemala. Se estudiará particularmente la recepción de obras argentinas en el Manual de Guerra Contrasubversiva (MGC) de Guatemala de fines de la década del setenta: el libro de Osiris Villegas, Guerra revolucionaria comunista y un folleto del ejército argentino, Instrucciones para lucha contra la subversión, ambos fechados en 1962. Se realiza una aproximación a dichas fuentes, a sus autores, al contexto de su producción y, sobre todo, a sus ideas. Finalmente, se sistematizan las principales ideas recibidas en el MGC, el mismo que el ejército de Guatemala utilizó durante el período que perpetró la mayor cantidad de violaciones a los derechos humanos (1978-1985).
La asesoría militar argentina en Honduras
Authors: Balerini Casal Emiliano Francisco
Published: July 2018

Este trabajo puede leerse la influencia que el Ejército argentino tuvo en las Fuerzas Armadas hondureñas para desestabilizar políticamente al gobierno del Frente Sandinista de Liberación Nacional (FSLN), así como a las guerrillas de El Salvador y Guatemala, a partir de 1980. Para poder explicar lo anterior es necesario hacer un breve recorrido por la historia que rodeó a la Junta Militar Argentina entre 1976 y 1983, y el éxito que tuvo con su política contrainsurgente.La extraterritorialización de su sistema represivo, propuesta en la Conferencia de Ejércitos Americanos (CEA), en noviembre de 1979 en Bogotá, Colombia, es un punto que se debe analizar, pues es a partir de esta propuesta formal de asesoramiento militar a distintos países de la región que se dio la intervención del país sudamericano en Centroamérica.El autor pretende contribuir a los estudios y al debate que en los últimos tiempos se realizan en la materia en distintas universidades de América Latina, como la UNAM, en México y la UBA, en Argentina. EL artículo representa un acercamiento a la forma en la que operó la dictadura militar argentina en Honduras, país que sirvió como base para que se entrenara La Contra.
Hormesis and immunity: A review
Authors: Csaba György
Published: July 2018

The hormesis concept demonstrates that in contrast to the toxic effect of high doses of materials, irradiation, etc., low doses of them are beneficial and, in addition, help to eliminate (prevent) the deleterious effect of high doses given after it. By this effect, it is an important factor of (human) evolution protecting man from harmful impacts, similarly to the role of immunity. However, immunity is also continuously influenced by hormetic effects of environmental [chemical (pollutions), physical (background irradiations and heat), etc.] and medical (drugs and therapeutic irradiations) and food interactions. In contrast to earlier beliefs, the no-threshold irradiation dogma is not valid in low-dose domains and here the hormesis concept is valid. Low-dose therapeutic irradiation, as well as background irradiations (by radon spas or moderately far from the epicenter of atomic bomb or nuclear facilities), is rather beneficial than destructive and the fear from them seems to be unreasonable from immunological point of view. Practically, all immune parameters are beneficially influenced by all forms of low-dose radiations.
Perancangan dan Simulasi Prototype Saklar Pengatur Lampu Ruangan Berbasis Visual Basic 6.0 (Otomatis dan Manual)
Authors: Kamelia,M.T Lia
Published: July 2018

Saklar adalah sebuah perangkat yang digunakan untuk menghubungkan dan memutuskan jaringan listrik. Pada penelitian ini prototype saklar yang dibuat menggunakan program Visual Basic 6.0, dengan sistem kontrol secara manual maupun otomatis. Kemudian rangkaian dihubungkan ke PC menggunakan konektor db25. Penggunaan saklar secara manual yaitu dengan memilih tombol mana yang ingin dipilih pada program Visual Basic 6.0 yang telah dibuat, maka lampu simulasi yang saklarnya ada pada tombol tersebut menyala atau jika dipilih kembali tombol tersebut maka lampu simulasi akan padam. Dengan adanya saklar manual ini yang terdapat pada program Visual Basic 6.0, akan mempermudah mengontrol penggunaan lampu disuatu ruangan, dan menghidupkan/memadamkan lampu simulasi dengan saklar yang saling berdampingan. Sedangkan untuk penggunaan secara otomatis yaitu dengan memilih tombol otomatis,maka secara otomatis lampu akan menyala dengan sendirinya sesuai jadwal yang telah dibuat. Hasil pengujian baik secara manual maupun otomatis diperoleh beberapa kesimpulan. Kesimpulan pertama Prototype simulasi saklar lampu yang bisa dikendalikan secara otomatis melalui PC berbasis visual basic telah dibuat dan berhasil mengendalikan lampu led, yang kedua pembuatan sintak program menggunakan Visual basic yang dibuat dengan 2 tipe pengontrolan, manual dan otomatis. Dan yang terakhir pengujian program dilakukan dengan simulasi menggunakan miniatur ruangan yang dikoneksikan ke PC melalui konektor db25. Dengan adanya penggunaan saklar otomatis yang terdapat pada program Visual Basic 6.0 ini, akan mengefesiensi waktu saat menyalakan lampu diruangan yang banyak.
Pengaruh Isolated Neighborhood-Averaging Filters Pada Kinect Structural Noise Sebagai Sistem Navigasi Robot Wild Thumper
Authors: Kurniawan Aditya , Wardani Kholilatul
Published: July 2018

Sensor kinect akan dikondisikan untuk mengambil sebuah benda hitam berbentuk persegi berukuran 10cm x 10cm secara tegak lurus pada sebuah background homogen (warna putih dengan RGB 255,255,255). Hasil data sensor kinect akan diambil menggunakan program visual basic 6.0 secara berkala sebanyak 10 kali tiap tahap dengan frekuensi satu kali / menit. Total tahap yang dilaksanakan adalah sebanyak 4 tahap. Sensor kinect diprogram untuk mengambil gambar objek tanpa proses blurring, dengan 1x blurring, 2x blurring dan 3x blurring menggunakan teknik Localized Neighbourhood-Averaging Filter. Hasil penginderaan sensor dari keempat sesi tersebut akan dianalisa berdasarkan tebal shadow (noise) pada tepi objek menggunakan statistik Pearson Correlation. Selanjutnya, mekanisme preprocessing sensor akan diujikan pada robot Wild Thumper.Pengaruh Isolated Neighbourhood-Averaging Mask terhadap banyaknya pixel noise yang dihasilkan oleh kinect memiliki pengaruh dengan tingkat medium dengan koefisien Pearson bernilai 0,4, dan Layer titik jenuh Neighbourhood-Averaging filter pada pixel noise yang dihasilkan oleh kinect adalah dua layer.
Rebuttal to M. E. Hassani's ``Foundations of Superluminal Relativistic Mechanics''
Authors: Sfarti Adrian
Published: July 2018

M. E. Hassani tries to construct the foundations for a superluminal mechanics. In the following note we will prove the premise of his paper to be wrong, rendering his whole paper as incorrect.
Localized Surface Plasmon Resonances with Spherical Metallic Nanoparticles
Authors: Ngo Minh Quang
Published: July 2018

In this work we review in part of our recent theoretical study on the electrical intensity enhancement in the dielectric medium surrounding metallic nanoparticles due to the effect of their localized surface plasmon resonance (LSPR). The known results in the case of a simple metallic spherical nanoparticle are presented and then extend them to the general case of complex network of the identical spherical metallic nanoparticles. For illustration, several typical lattices of identical spherical metallic nanoparticles will be treated. The findings of electrical intensity enhancements and plasmonic resonance wavelengths of the single and the network of the metallic nanoparticles are obtained based on the analytical expressions. The theoretical results were compared and shown the good agreement with simulation results. The simulation of the LSPRs and the electrical intensity enhancements was performed using the boundary element method.
Optimal Carrier Concentration for High Thermoelectric Performance of Lead Substituted Bismuth Telluride in p-Type Doping
Authors: Tran Van Quang
Published: July 2018

Bi\(_{2}\)Te\(_{3}\) and its alloys are the well-known state-of-the-art thermoelectric materials operating at around room temperature. With lead substituted, the newly formed quasi-binary compound PbBi\(_{4}\)Te\(_{7}\), shows relatively high electrical conductivity and Seebeck coefficient. In this report, we employed the solution of the Boltzmann Transport Equation in a constant relaxation-time approximation within a first-principles density-functional-theory calculation to explore the role of the electronic thermal conductivity, \(\kappa _{e}\), on the thermoelectric performance of the compound with p-type doping. Results show that \(\kappa _{e}\) increases drastically with the increases of both temperature and carrier concentration. Even the power factor has been found to be markedly improved with the increase of the carrier concentration, a rapid increase of \(\kappa _{e}\) emerges as a big hindrance to improve the dimensionless figure of merit, ZT, of the compound. This is responsible for the limit of ZT. The larger ZT is found in low temperatures and carrier concentrations. The highest ZT of about 0.48 occurs at 223 K and at the carrier concentration of \(6\times 10^{17}\)cm\(^{ - 3}\). At room temperature the maximum ZT is slightly smaller. We demonstrated that at a particular temperature to maximize the thermoelectric performance of the compound, the carrier concentration must be optimized. Results show that the compound with p-type doping is a promising thermoelectric materials operating at around room temperature.
Biodiversity of the metazoan parasites of Prochilodus lineatus (Valenciennes, 1837) (Characiformes: Prochilodontidae) in anthropized environments from the Batalha River, São Paulo State, Brazil
Authors: Leite Lucas Aparecido Rosa , Pelegrini Larissa Sbeghen , Agostinho Beatriz Narciso , Azevedo Rodney Kozlowiski de , Abdallah Vanessa Doro
Published: July 2018

Abstract: Biodiversity of fish parasites is a field of significant growth worldwide, whether due to the advancement of fish farms or the important role of these organisms as indicators of environment quality and ecosystem health, making them useful tools in the conservation and maintenance of the biodiversity as a whole. The objectives of this study were to evaluate the structure and composition of the parasitic fauna of Prochilodus lineatus collected from two structurally distinct stretches of the Batalha River. Fifty specimens of P. lineatus were collected between June 2015 and June 2016. Of these 50 hosts, 875 parasite specimens were collected, divided into 30 species, belonging to seven groups: Myxozoa, Monogenea, Digenea, Acanthocephala, Nematoda, Copepoda and Hirudinea. In addition to new records of known parasites of P. lineatus for this locality, 13 species were newly recorded parasitizing this fish, including a new monogenean species (Tereancistrum sp. n.), with Monogenea being the most representative class in the study. The findings of this study expands the known geographic distribution of these parasite species and helps to increase the knowledge of the biodiversity of these organisms in different hosts and environments. In general, the structure and composition of the P. lineatus parasitic fauna did not seem to be influenced by the structural characteristics of the two stretches studied, due to the migratory habits of the host.
Abdominal B-mode and Doppler ultrasonography of chemically restrained agouti (Dasyprocta prymnolopha Wagler, 1831)
Authors: Pessoa Gerson T. , Sousa Francisco C.A. , Rodrigues Renan P.S. , Moura Laecio S. , Sanches Marina P. , Ambrósio Carlos E. , Silva Andrezza B.S. , Alves Flávio R.
Published: July 2018

ABSTRACT: Agoutis are small-sized wild animals whose body weight can reach up to 4kg, and are found throughout Brazil. They are considered important seed dispersers, especially for big trees and there are species that rely almost exclusively on these animals for their territorial distribution. The objective of the present study was B scan and Doppler ultrasound characterization of the abdominal organs of healthy agoutis reared in captivity. Fifteen agoutis, chemically restrained, were used from the Nucleus for Wild Animal Studies and Conservation (Núcleo de Estudos e Preservação de Animais Silvestres - NEPAS), CCA-UFPI, submitted to B scan and Doppler ultrasound examination. The urinary bladder wall was hyperechogenic, thin, smooth and regular throughout its anatomic path, with 0.09±0.03cm mean thickness. The kidneys showed fine and homogeneous echotexture, preserved global echogenicity, hyperechogenic in relation to the spleen and isoechogenic or discreetly hyperechogenic in relation to the liver. The spectral Doppler trace showed systolic and diastolic peaks, wide and thread-like, with low flow resistance and a continuous and full diastolic portion that decreased gradually during the diastole (75.83±1.42cm/s, for the right kidney and 80.43±1.22cm/s, for the left kidney). The right adrenal gland was 0.61-1.18cm long and 0.17-0.32cm in diameter, while the left adrenal gland was 0.62-1.16 long with 0.14-0.25cm diameter. The agouti spleen was filiform in shape, with pointed poles and 1.02±0.18cm in diameter. The agouti liver occupied all the abdominal cavity cranial space in direct contact with the diaphragm. The intrahepatic vascular flow allowed individualization of the portal vein (PV) and hepatic vein (HV). The portal veins were distinguished from the hepatic veins mainly by their wall echogenic pattern. The pancreas was 0.51±0.1 cm thick and the pancreatic duct measured 0.12±0.02cm. The stomach was placed to the left the spleen and to the right of the proximal intestine and the transversal colon and the walls were 0.16±0.05cm thick. The abdominal aorta was 0.43±0.04cm in diameter and showed 95.2±2.16cm/s vascular flow. This study characterized agouti organs and abdominal blood vessels by B scan and Doppler ultrasound, that permitted definition of the size, shape, position, echogenicity and echotexture of the anatomic constituents and established reference values for the vascular network and blood flow in the species.
Liderança do enfermeiro e sua relação com o ambiente de trabalho hospitalar
Authors: Balsanelli Alexandre Pazetto , David Daiane Rossi , Ferrari Thais Guglielminetti
Published: July 2018

Resumo Objetivo Analisar o ambiente de trabalho do enfermeiro considerando: autonomia, controle, relações entre médicos e enfermeiros e suporte organizacional; verificar o estilo de liderança ideal, na percepção do enfermeiro, e o real de acordo com a avaliação de um dos seus liderados; correlacionar as variáveis ambiente de trabalho e liderança real. Métodos Estudo correlacional realizado nas unidades assistenciais dum hospital geral de São Paulo, SP, Brasil. A amostra de conveniência constituiu-se de 62 duplas (enfermeiros e técnicos/auxiliares de enfermagem). Os enfermeiros responderam três instrumentos: 1-) caracterização; 2-) Brasilian Nursing Work Index Revised (B-NWI-R) que mensura: autonomia, controle, relações entre médicos e enfermeiros e suporte organizacional; e 3-) Grid & Liderança em Enfermagem: comportamento ideal que mensura cinco estilos: 1.1, 1.9, 5.5, 9.1 e 9.9. Os técnicos/auxiliares em enfermagem responderam: 1-) caracterização e 2-) Grid & Liderança em Enfermagem: comportamento real considerando o enfermeiro como líder imediato. Os dados foram analisados com análise de variância (ANOVA- p ≤0,05). Resultados A média do B-NWI-R foi de 2,2. O estilo 1.1 foi o considerado ideal pelos enfermeiros (58,1%), seguido de 35,5% do 9.1. Esses foram os mais apontados pelos técnicos, porém, nesta sequência 9.1 e 1.1. Não houve relação do ambiente de trabalho com liderança real do enfermeiro (p=0,39). Conclusão O ambiente de trabalho mostrou-se favorável à prática de enfermagem. O estilo de liderança ideal dos enfermeiros não apresentou correspondência com o real avaliado pelos técnicos ou auxiliares de enfermagem e o ambiente de trabalho não se relacionou com a liderança dos enfermeiros.
Transductive Rademacher Complexity and its Applications
Authors: El-Yaniv R. , Pechyony D.
Published: July 2018

We develop a technique for deriving data-dependent error bounds for transductive learning algorithms based on transductive Rademacher complexity. Our technique is based on a novel general error bound for transduction in terms of transductive Rademacher complexity, together with a novel bounding technique for Rademacher averages for particular algorithms, in terms of their "unlabeled-labeled" representation. This technique is relevant to many advanced graph-based transductive algorithms and we demonstrate its effectiveness by deriving error bounds to three well known algorithms. Finally, we present a new PAC-Bayesian bound for mixtures of transductive algorithms based on our Rademacher bounds.
Automated Reasoning in Modal and Description Logics via SAT Encoding: the Case Study of K(m)/ALC-Satisfiability
Authors: Sebastiani R. , Vescovi M.
Published: July 2018

In the last two decades, modal and description logics have been applied to numerous areas of computer science, including knowledge representation, formal verification, database theory, distributed computing and, more recently, semantic web and ontologies. For this reason, the problem of automated reasoning in modal and description logics has been thoroughly investigated. In particular, many approaches have been proposed for efficiently handling the satisfiability of the core normal modal logic K(m), and of its notational variant, the description logic ALC. Although simple in structure, K(m)/ALC is computationally very hard to reason on, its satisfiability being PSPACE-complete.

In this paper we start exploring the idea of performing automated reasoning tasks in modal and description logics by encoding them into SAT, so that to be handled by state-of-the-art SAT tools; as with most previous approaches, we begin our investigation from the satisfiability in K(m). We propose an efficient encoding, and we test it on an extensive set of benchmarks, comparing the approach with the main state-of-the-art tools available. Although the encoding is necessarily worst-case exponential, from our experiments we notice that, in practice, this approach can handle most or all the problems which are at the reach of the other approaches, with performances which are comparable with, or even better than, those of the current state-of-the-art tools.
Compiling Uncertainty Away in Conformant Planning Problems with Bounded Width
Authors: Palacios H. , Geffner H.
Published: July 2018

Conformant planning is the problem of finding a sequence of actions for achieving a goal in the presence of uncertainty in the initial state or action effects. The problem has been approached as a path-finding problem in belief space where good belief representations and heuristics are critical for scaling up. In this work, a different formulation is introduced for conformant problems with deterministic actions where they are automatically converted into classical ones and solved by an off-the-shelf classical planner. The translation maps literals L and sets of assumptions t about the initial situation, into new literals KL/t that represent that L must be true if t is initially true. We lay out a general translation scheme that is sound and establish the conditions under which the translation is also complete. We show that the complexity of the complete translation is exponential in a parameter of the problem called the conformant width, which for most benchmarks is bounded. The planner based on this translation exhibits good performance in comparison with existing planners, and is the basis for T0, the best performing planner in the Conformant Track of the 2006 International Planning Competition.
Trust-Based Mechanisms for Robust and Efficient Task Allocation in the Presence of Execution Uncertainty
Authors: Ramchurn S. D. , Mezzetti C. , Giovannucci A. , Rodriguez-Aguilar J. A. , Dash R. K. , Jennings N. R.
Published: July 2018

Vickrey-Clarke-Groves (VCG) mechanisms are often used to allocate tasks to selfish and rational agents. VCG mechanisms are incentive compatible, direct mechanisms that are efficient (i.e., maximise social utility) and individually rational (i.e., agents prefer to join rather than opt out). However, an important assumption of these mechanisms is that the agents will "always" successfully complete their allocated tasks. Clearly, this assumption is unrealistic in many real-world applications, where agents can, and often do, fail in their endeavours. Moreover, whether an agent is deemed to have failed may be perceived differently by different agents. Such subjective perceptions about an agent's probability of succeeding at a given task are often captured and reasoned about using the notion of "trust". Given this background, in this paper we investigate the design of novel mechanisms that take into account the trust between agents when allocating tasks.

Specifically, we develop a new class of mechanisms, called "trust-based mechanisms", that can take into account multiple subjective measures of the probability of an agent succeeding at a given task and produce allocations that maximise social utility, whilst ensuring that no agent obtains a negative utility. We then show that such mechanisms pose a challenging new combinatorial optimisation problem (that is NP-complete), devise a novel representation for solving the problem, and develop an effective integer programming solution (that can solve instances with about 2x10^5 possible allocations in 40 seconds).
Complex Question Answering: Unsupervised Learning Approaches and Experiments
Authors: Chali Y. , Joty S. R. , Hasan S. A.
Published: July 2018

Complex questions that require inferencing and synthesizing information from multiple documents can be seen as a kind of topic-oriented, informative multi-document summarization where the goal is to produce a single text as a compressed version of a set of documents with a minimum loss of relevant information. In this paper, we experiment with one empirical method and two unsupervised statistical machine learning techniques: K-means and Expectation Maximization (EM), for computing relative importance of the sentences. We compare the results of these approaches. Our experiments show that the empirical approach outperforms the other two techniques and EM performs better than K-means. However, the performance of these approaches depends entirely on the feature set used and the weighting of these features. In order to measure the importance and relevance to the user query we extract different kinds of features (i.e. lexical, lexical semantic, cosine similarity, basic element, tree kernel based syntactic and shallow-semantic) for each of the document sentences. We use a local search technique to learn the weights of the features. To the best of our knowledge, no study has used tree kernel functions to encode syntactic/semantic information for more complex tasks such as computing the relatedness between the query sentences and the document sentences in order to generate query-focused summaries (or answers to complex questions). For each of our methods of generating summaries (i.e. empirical, K-means and EM) we show the effects of syntactic and shallow-semantic features over the bag-of-words (BOW) features.
Multilingual Part-of-Speech Tagging: Two Unsupervised Approaches
Authors: Naseem T. , Snyder B. , Eisenstein J. , Barzilay R.
Published: July 2018

We demonstrate the effectiveness of multilingual learning for unsupervised part-of-speech tagging. The central assumption of our work is that by combining cues from multiple languages, the structure of each becomes more apparent. We consider two ways of applying this intuition to the problem of unsupervised part-of-speech tagging: a model that directly merges tag structures for a pair of languages into a single sequence and a second model which instead incorporates multilingual context using latent variables. Both approaches are formulated as hierarchical Bayesian models, using Markov Chain Monte Carlo sampling techniques for inference. Our results demonstrate that by incorporating multilingual evidence we can achieve impressive performance gains across a range of scenarios. We also found that performance improves steadily as the number of available languages increases.
Text Relatedness Based on a Word Thesaurus
Authors: Tsatsaronis G. , Varlamis I. , Vazirgiannis M.
Published: July 2018

The computation of relatedness between two fragments of text in an automated manner requires taking into account a wide range of factors pertaining to the meaning the two fragments convey, and the pairwise relations between their words. Without doubt, a measure of relatedness between text segments must take into account both the lexical and the semantic relatedness between words. Such a measure that captures well both aspects of text relatedness may help in many tasks, such as text retrieval, classification and clustering. In this paper we present a new approach for measuring the semantic relatedness between words based on their implicit semantic links. The approach exploits only a word thesaurus in order to devise implicit semantic links between words. Based on this approach, we introduce Omiotis, a new measure of semantic relatedness between texts which capitalizes on the word-to-word semantic relatedness measure (SR) and extends it to measure the relatedness between texts. We gradually validate our method: we first evaluate the performance of the semantic relatedness measure between individual words, covering word-to-word similarity and relatedness, synonym identification and word analogy; then, we proceed with evaluating the performance of our method in measuring text-to-text semantic relatedness in two tasks, namely sentence-to-sentence similarity and paraphrase recognition. Experimental evaluation shows that the proposed method outperforms every lexicon-based method of semantic relatedness in the selected tasks and the used data sets, and competes well against corpus-based and hybrid approaches.
Grounding FO and FO(ID) with Bounds
Authors: Wittocx J. , Mariën M. , Denecker M.
Published: July 2018

Grounding is the task of reducing a first-order theory and finite domain to an equivalent propositional theory. It is used as preprocessing phase in many logic-based reasoning systems. Such systems provide a rich first-order input language to a user and can rely on efficient propositional solvers to perform the actual reasoning.

Besides a first-order theory and finite domain, the input for grounders contains in many applications also additional data. By exploiting this data, the size of the grounder's output can often be reduced significantly. A common practice to improve the efficiency of a grounder in this context is by manually adding semantically redundant information to the input theory, indicating where and when the grounder should exploit the data. In this paper we present a method to compute and add such redundant information automatically. Our method therefore simplifies the task of writing input theories that can be grounded efficiently by current systems.

We first present our method for classical first-order logic (FO) theories. Then we extend it to FO(ID), the extension of FO with inductive definitions, which allows for more concise and comprehensive input theories. We discuss implementation issues and experimentally validate the practical applicability of our method.
A Survey of Paraphrasing and Textual Entailment Methods
Authors: Androutsopoulos I. , Malakasiotis P.
Published: July 2018

Paraphrasing methods recognize, generate, or extract phrases, sentences, or longer natural language expressions that convey almost the same information. Textual entailment methods, on the other hand, recognize, generate, or extract pairs of natural language expressions, such that a human who reads (and trusts) the first element of a pair would most likely infer that the other element is also true. Paraphrasing can be seen as bidirectional textual entailment and methods from the two areas are often similar. Both kinds of methods are useful, at least in principle, in a wide range of natural language processing applications, including question answering, summarization, text generation, and machine translation. We summarize key ideas from the two areas by considering in turn recognition, generation, and extraction methods, also pointing to prominent articles and resources.
Theta*: Any-Angle Path Planning on Grids
Authors: Daniel K. , Nash A. , Koenig S. , Felner A.
Published: July 2018

Grids with blocked and unblocked cells are often used to represent terrain in robotics and video games. However, paths formed by grid edges can be longer than true shortest paths in the terrain since their headings are artificially constrained. We present two new correct and complete any-angle path-planning algorithms that avoid this shortcoming. Basic Theta* and Angle-Propagation Theta* are both variants of A* that propagate information along grid edges without constraining paths to grid edges. Basic Theta* is simple to understand and implement, fast and finds short paths. However, it is not guaranteed to find true shortest paths. Angle-Propagation Theta* achieves a better worst-case complexity per vertex expansion than Basic Theta* by propagating angle ranges when it expands vertices, but is more complex, not as fast and finds slightly longer paths. We refer to Basic Theta* and Angle-Propagation Theta* collectively as Theta*. Theta* has unique properties, which we analyze in detail. We show experimentally that it finds shorter paths than both A* with post-smoothed paths and Field D* (the only other version of A* we know of that propagates information along grid edges without constraining paths to grid edges) with a runtime comparable to that of A* on grids. Finally, we extend Theta* to grids that contain unblocked cells with non-uniform traversal costs and introduce variants of Theta* which provide different tradeoffs between path length and runtime.
Which Clustering Do You Want? Inducing Your Ideal Clustering with Minimal Feedback
Authors: Dasgupta S. , Ng V.
Published: July 2018

While traditional research on text clustering has largely focused on grouping documents by topic, it is conceivable that a user may want to cluster documents along other dimensions, such as the author's mood, gender, age, or sentiment. Without knowing the user's intention, a clustering algorithm will only group documents along the most prominent dimension, which may not be the one the user desires. To address the problem of clustering documents along the user-desired dimension, previous work has focused on learning a similarity metric from data manually annotated with the user's intention or having a human construct a feature space in an interactive manner during the clustering process. With the goal of reducing reliance on human knowledge for fine-tuning the similarity function or selecting the relevant features required by these approaches, we propose a novel active clustering algorithm, which allows a user to easily select the dimension along which she wants to cluster the documents by inspecting only a small number of words. We demonstrate the viability of our algorithm on a variety of commonly-used sentiment datasets.
Fast Set Bounds Propagation Using a BDD-SAT Hybrid
Authors: Gange G. , Stuckey P. J. , Lagoon V.
Published: July 2018

Binary Decision Diagram (BDD) based set bounds propagation is a powerful approach to solving set-constraint satisfaction problems. However, prior BDD based techniques in- cur the significant overhead of constructing and manipulating graphs during search. We present a set-constraint solver which combines BDD-based set-bounds propagators with the learning abilities of a modern SAT solver. Together with a number of improvements beyond the basic algorithm, this solver is highly competitive with existing propagation based set constraint solvers.
A Constraint Satisfaction Framework for Executing Perceptions and Actions in Diagrammatic Reasoning
Authors: Banerjee B. , Chandrasekaran B.
Published: July 2018

Diagrammatic reasoning (DR) is pervasive in human problem solving as a powerful adjunct to symbolic reasoning based on language-like representations. The research reported in this paper is a contribution to building a general purpose DR system as an extension to a SOAR-like problem solving architecture. The work is in a framework in which DR is modeled as a process where subtasks are solved, as appropriate, either by inference from symbolic representations or by interaction with a diagram, i.e., perceiving specified information from a diagram or modifying/creating objects in a diagram in specified ways according to problem solving needs. The perceptions and actions in most DR systems built so far are hand-coded for the specific application, even when the rest of the system is built using the general architecture. The absence of a general framework for executing perceptions/actions poses as a major hindrance to using them opportunistically -- the essence of open-ended search in problem solving.

Our goal is to develop a framework for executing a wide variety of specified perceptions and actions across tasks/domains without human intervention. We observe that the domain/task-specific visual perceptions/actions can be transformed into domain/task-independent spatial problems. We specify a spatial problem as a quantified constraint satisfaction problem in the real domain using an open-ended vocabulary of properties, relations and actions involving three kinds of diagrammatic objects -- points, curves, regions. Solving a spatial problem from this specification requires computing the equivalent simplified quantifier-free expression, the complexity of which is inherently doubly exponential. We represent objects as configuration of simple elements to facilitate decomposition of complex problems into simpler and similar subproblems. We show that, if the symbolic solution to a subproblem can be expressed concisely, quantifiers can be eliminated from spatial problems in low-order polynomial time using similar previously solved subproblems. This requires determining the similarity of two problems, the existence of a mapping between them computable in polynomial time, and designing a memory for storing previously solved problems so as to facilitate search. The efficacy of the idea is shown by time complexity analysis. We demonstrate the proposed approach by executing perceptions and actions involved in DR tasks in two army applications.
Logical Foundations of RDF(S) with Datatypes
Authors: De Bruijn J. , Heymans S.
Published: July 2018

The Resource Description Framework (RDF) is a Semantic Web standard that provides a data language, simply called RDF, as well as a lightweight ontology language, called RDF Schema. We investigate embeddings of RDF in logic and show how standard logic programming and description logic technology can be used for reasoning with RDF. We subsequently consider extensions of RDF with datatype support, considering D entailment, defined in the RDF semantics specification, and D* entailment, a semantic weakening of D entailment, introduced by ter Horst. We use the embeddings and properties of the logics to establish novel upper bounds for the complexity of deciding entailment. We subsequently establish two novel lower bounds, establishing that RDFS entailment is PTime-complete and that simple-D entailment is coNP-hard, when considering arbitrary datatypes, both in the size of the entailing graph. The results indicate that RDFS may not be as lightweight as one may expect.
A Utility-Theoretic Approach to Privacy in Online Services
Authors: Krause A. , Horvitz E.
Published: July 2018

Online offerings such as web search, news portals, and e-commerce applications face the challenge of providing high-quality service to a large, heterogeneous user base. Recent efforts have highlighted the potential to improve performance by introducing methods to personalize services based on special knowledge about users and their context. For example, a user's demographics, location, and past search and browsing may be useful in enhancing the results offered in response to web search queries. However, reasonable concerns about privacy by both users, providers, and government agencies acting on behalf of citizens, may limit access by services to such information. We introduce and explore an economics of privacy in personalization, where people can opt to share personal information, in a standing or on-demand manner, in return for expected enhancements in the quality of an online service. We focus on the example of web search and formulate realistic objective functions for search efficacy and privacy. We demonstrate how we can find a provably near-optimal optimization of the utility-privacy tradeoff in an efficient manner. We evaluate our methodology on data drawn from a log of the search activity of volunteer participants. We separately assess users preferences about privacy and utility via a large-scale survey, aimed at eliciting preferences about peoples willingness to trade the sharing of personal data in returns for gains in search efficiency. We show that a significant level of personalization can be achieved using a relatively small amount of information about users.
A Logical Study of Partial Entailment
Authors: Zhou Y. , Zhang Y.
Published: July 2018

We introduce a novel logical notion--partial entailment--to propositional logic. In contrast with classical entailment, that a formula P partially entails another formula Q with respect to a background formula set \Gamma intuitively means that under the circumstance of \Gamma, if P is true then some "part" of Q will also be true. We distinguish three different kinds of partial entailments and formalize them by using an extended notion of prime implicant. We study their semantic properties, which show that, surprisingly, partial entailments fail for many simple inference rules. Then, we study the related computational properties, which indicate that partial entailments are relatively difficult to be computed. Finally, we consider a potential application of partial entailments in reasoning about rational agents.
Evaluating Temporal Graphs Built from Texts via Transitive Reduction
Authors: Tannier X. , Muller P.
Published: July 2018

Temporal information has been the focus of recent attention in information extraction, leading to some standardization effort, in particular for the task of relating events in a text. This task raises the problem of comparing two annotations of a given text, because relations between events in a story are intrinsically interdependent and cannot be evaluated separately. A proper evaluation measure is also crucial in the context of a machine learning approach to the problem. Finding a common comparison referent at the text level is not obvious, and we argue here in favor of a shift from event-based measures to measures on a unique textual object, a minimal underlying temporal graph, or more formally the transitive reduction of the graph of relations between event boundaries. We support it by an investigation of its properties on synthetic data and on a well-know temporal corpus.
False-Name Manipulations in Weighted Voting Games
Authors: Aziz H. , Bachrach Y. , Elkind E. , Paterson M.
Published: July 2018

Weighted voting is a classic model of cooperation among agents in decision-making domains. In such games, each player has a weight, and a coalition of players wins the game if its total weight meets or exceeds a given quota. A player's power in such games is usually not directly proportional to his weight, and is measured by a power index, the most prominent among which are the Shapley-Shubik index and the Banzhaf index.In this paper, we investigate by how much a player can change his power, as measured by the Shapley-Shubik index or the Banzhaf index, by means of a false-name manipulation, i.e., splitting his weight among two or more identities. For both indices, we provide upper and lower bounds on the effect of weight-splitting. We then show that checking whether a beneficial split exists is NP-hard, and discuss efficient algorithms for restricted cases of this problem, as well as randomized algorithms for the general case. We also provide an experimental evaluation of these algorithms. Finally, we examine related forms of manipulative behavior, such as annexation, where a player subsumes other players, or merging, where several players unite into one. We characterize the computational complexity of such manipulations and provide limits on their effects. For the Banzhaf index, we describe a new paradox, which we term the Annexation Non-monotonicity Paradox.
Properties of Bethe Free Energies and Message Passing in Gaussian Models
Authors: Cseke B. , Heskes T.
Published: July 2018

We address the problem of computing approximate marginals in Gaussian probabilistic models by using mean field and fractional Bethe approximations. We define the Gaussian fractional Bethe free energy in terms of the moment parameters of the approximate marginals, derive a lower and an upper bound on the fractional Bethe free energy and establish a necessary condition for the lower bound to be bounded from below. It turns out that the condition is identical to the pairwise normalizability condition, which is known to be a sufficient condition for the convergence of the message passing algorithm. We show that stable fixed points of the Gaussian message passing algorithm are local minima of the Gaussian Bethe free energy. By a counterexample, we disprove the conjecture stating that the unboundedness of the free energy implies the divergence of the message passing algorithm.
Redistribution Mechanisms for Assignment of Heterogeneous Objects
Authors: Gujar S. P. , Narahari Y
Published: July 2018

There are p heterogeneous objects to be assigned to n competing agents (n > p) each with unit demand. It is required to design a Groves mechanism for this assignment problem satisfying weak budget balance, individual rationality, and minimizing the budget imbalance. This calls for designing an appropriate rebate function. When the objects are identical, this problem has been solved which we refer as WCO mechanism. We measure the performance of such mechanisms by the redistribution index. We first prove an impossibility theorem which rules out linear rebate functions with non-zero redistribution index in heterogeneous object assignment. Motivated by this theorem, we explore two approaches to get around this impossibility. In the first approach, we show that linear rebate functions with non-zero redistribution index are possible when the valuations for the objects have a certain type of relationship and we design a mechanism with linear rebate function that is worst case optimal. In the second approach, we show that rebate functions with non-zero efficiency are possible if linearity is relaxed. We extend the rebate functions of the WCO mechanism to heterogeneous objects assignment and conjecture them to be worst case optimal.
A Probabilistic Framework for Learning Kinematic Models of Articulated Objects
Authors: Sturm J. , Stachniss C. , Burgard W.
Published: July 2018

Robots operating in domestic environments generally need to interact with articulated objects, such as doors, cabinets, dishwashers or fridges. In this work, we present a novel, probabilistic framework for modeling articulated objects as kinematic graphs. Vertices in this graph correspond to object parts, while edges between them model their kinematic relationship. In particular, we present a set of parametric and non-parametric edge models and how they can robustly be estimated from noisy pose observations. We furthermore describe how to estimate the kinematic structure and how to use the learned kinematic models for pose prediction and for robotic manipulation tasks. We finally present how the learned models can be generalized to new and previously unseen objects. In various experiments using real robots with different camera systems as well as in simulation, we show that our approach is valid, accurate and efficient. Further, we demonstrate that our approach has a broad set of applications, in particular for the emerging fields of mobile manipulation and service robotics.