bluuebunny/crossref_metadata_2025 huggingface dataset:
Nomophobia and smartphone addiction: do the variables age and sex explain this relationship?
Authors: Guimarães Clara Lohana Cardoso , Oliveira Lays Brunnyeli Santos de , Pereira Rayssa Soares , Silva Paulo Gregório Nascimento da , Gouveia Valdiney Veloso
Published: September 2022

Abstract This study aimed to identify the extent nomophobia explains smartphone addiction, controlling for age and gender effects. Participants were 316 people from the 22 Brazilian states (Mage = 28.1 years), most from Paraíba (38.9%) and Piauí (16.5%), equally distributed between genders. They answered the Nomophobia Questionnaire, the Smartphone Addition Scale and demographic questions. The results demonstrate that the factors of the nomophobia measure explained smartphone addiction, indicating that more nomophobic behavior equates to increased smartphone addiction, especially in the younger participants, there was no difference regarding gender. These findings are discussed according to the literature on adherence to new technologies, revealing the current problem of smartphone addiction in young people.
Evidências de Validade da GAD-7 em Adolescentes Brasileiros
Authors: Leite Michelle de Farias , Faro André
Published: September 2022

Resumo O objetivo deste estudo foi investigar evidências validade para a escala Generalized Anxiety Disorder (GAD-7) em adolescentes brasileiros, bem como validade concorrente para esta escala e apresentar a distribuição social do Transtorno de Ansiedade Generalizada (TAG). Participaram 302 adolescentes, com idades entre 15 e 19 anos, de ambos os sexos. Aplicou-se o questionário sociodemográfico, a GAD-7, a Hospital Anxiety and Depression Scale (HADS) e o Patient Health Questionnaire (PHQ-9). Os resultados da Análise Fatorial Exploratória (AFE) atestaram a unidimensionalidade da GAD-7 e indicaram consistência interna satisfatória. As evidências de validade concorrente apresentaram associações estatisticamente significativas e positivas entre a GAD-7 e as escalas PHQ-9 e HADS-A. Quanto à distribuição social, aproximadamente metade da amostra apresentou a ocorrência de sintomatologia positiva para TAG, sendo mais comum para o sexo feminino e em adolescentes mais jovens. Esses dados sugerem que a GAD-7 apresenta adequadas propriedades psicométricas para rastreamento de ansiedade em adolescentes.
Epidemiological, clinical and laboratory aspects of Angiostrongylus cantonensis infection: an integrative review
Authors: Carvalho M. S. N. , Carvalho M. R. , Santos J. A. O. , Barbosa N. D. , Melo L. C. , Costa F. H. M. , Carvalho J. P. F. , Messias H. B. G. , Fonseca S. A. , Souza M. A. , Ferreira-Júnior G. C. , Lima R. F. , Costa J. G. , Cavalcanti M. G. S. , Matos-Rocha T. J.
Published: September 2022

Abstract This integrative literature review study analyzes the findings of the last 5 years of the parasite Angiostrongylus cantonensis. It is known that this nematode is found in the pulmonary arteries of rats, where it remains as a definitive host. From mice, the cycle spreads to animals, such as snails, which in contact with humans can trigger the disease. In humans, the parasite causes several neurological, abdominal manifestations and mainly meningitis. Based on the review of studies, its epidemiology shows worldwide distribution, although there are endemic cases for this parasite, such as asian countries. Laboratory findings generally showed altered CSF with turbidity, increased protein and eosinophilia, which generated meningeal signs in the patient, moreover MRI exams showed multiple alterations. Rare findings of the nematode in the eyeball, lung and signs of peritoneal inflammation were reported, which requires further studies to understand the whole pathophysiology. Finally, conservative treatment based on anthelmintics and anti-inflammatories brought good responses, although there are reports of deaths, which demonstrates the importance in the prevention and therapy of this disease.
The application and benefits of digital technologies for agri-food value chain: Evidence from an emerging country
Authors: Mikhailov Andrei , Camboim Guilherme F. , Reichert Fernanda M. , Zawislak Paulo A.
Published: September 2022

ABSTRACT Purpose: Many academic and technical studies have explored information and communications technology (ICT) applications in the agri-food sector from the farmers’ perspective. However, the technology supplier perspective on the ICT application has been largely overlooked. This paper aims to analyze how digital technologies are used within the agri-food value chain and their benefits and advantages from the technology supplier perspective. Originality/value: First, the study analyzed the benefits of ICT for the agri-food sector from the technology supplier perspective. Second, it comprised the integrated analysis of the complete set of ICT applied to the entire agri-food value chain. Third, we guaranteed the study’s replicability by using a straightforward methodological approach. Design/methodology/approach: Exploratory study with a descriptive approach was employed to map the complete set of digital technologies commercialized by 131 agri-food technology companies. The Organisation for Economic Co-operation and Development’s (OECD) (2018) typology for ICT solutions was used to identify technology types. The NVIVO software cluster analysis was applied to the data related to the benefits and advantages of the firms’ ICT solutions. Findings: We identified that cost reduction and rapid decision-making are the essential benefits of ICT. It was found that the ICT field in the agri-food sector is composed of different companies’ generations, and many are not startups. We identified two new phenomena: agricultural servitization, which comprehends the increasing importance of services as crucial input for agricultural production, and agricultural manufacturing, which refers to increasing control over production factors in agriculture.
Preditores da adoção de sistemas de integração lavoura-pecuária em São Paulo e o papel dos intermediários da inovação
Authors: Vinholis Marcela de Mello Brandão , Souza Filho Hildo Meirelles de , Carrer Marcelo José
Published: September 2022

Resumo: Este artigo tem como objetivo propor um modelo analítico para identificar preditores de regiões propensas à difusão de tecnologia de processo, bem como identificar e descrever funções de apoio à inovação. Utilizou-se as abordagens teóricas de difusão de inovações e de intermediários da inovação. Analisou-se a adoção de sistemas de integração lavoura-pecuária (ILP) no estado de São Paulo. O método proposto consistiu de (i) revisão da literatura sobre adoção e difusão de inovações e intermediários da inovação, (ii) um survey para identificar fatores que influenciam a adoção de ILP e (iii) a comparação de dois municípios com elevada difusão de ILP com sua região de desenvolvimento rural (EDR). Foram utilizados dados censitários sobre aspectos organizacionais e institucionais da região e características das propriedades rurais. Demonstrou-se que os preditores são: tamanho da propriedade; atividade pecuária e tipo de manejo predominantes; participação em cooperativa, sindicato rural e associação de produtores; além do acesso a serviços de extensão, seguro e crédito rural. Identificou-se que instituições e organizações atuam como intermediários da inovação, facilitando a interação e conexão entre os atores e promovendo serviços essenciais de apoio à adoção de tecnologias agrícolas.
Tensiones entre el movimiento indígena y el Estado a la luz de la trayectoria de las Bartolinas en Bolivia
Authors: Cuadros Claudia Cecilia Arce
Published: September 2022

Resumen Las dinámicas de conflictividad entre el movimiento campesino indígena y el Estado en Bolivia son examinadas a la luz de la trayectoria política y las disputas que han conformado los periodos de vida de la Confederación Nacional de Mujeres Campesinas Indígenas Originarias ‘Bartolina Sisa’ (1978-2018) y son interpretadas en clave de autonomía. Emergieron aprovechando una fisura en el movimiento campesino indígena, impulsaron un proyecto de representación no mediada o autorrepresentación política que derivó en la conformación de un instrumento político con el que lograron el control hegemónico del Estado. En un contexto de disponibilidad para su participación, a través de su doble militancia, transitan hacia la institucionalidad estatal pero su incorporación es contenida como un ejercicio de disciplinamiento. El desplazamiento de las organizaciones y la mayor centralidad del instrumento político durante la última década han reactualizado el dilema de la autonomía del movimiento campesino.
Efeitos da raça/cor e gênero da pesquisadora ou do pesquisador na pesquisa empírica: impactos na classificação racial de respondentes de um survey
Authors: Pereira Bruna Cristina Jaquetto , Siqueira João Paulo
Published: September 2022

Resumo Este artigo trata dos impactos da raça/cor ou do gênero das pessoas que conduzem a pesquisa sobre a autodeclaração de raça/cor de participantes. Para analisar o fenômeno, consideramos as respostas ao survey e as percepções de pesquisadores e pesquisadoras que aplicaram o survey em 2019 como parte da pesquisa Percepções Raciais no Distrito Federal. Utilizamos, para tanto, métodos qualitativos – breves relatos das pessoas que conduziram as entrevistas – e quantitativos. Os resultados sugerem a existência de um efeito complexo tanto da raça/cor das pessoas pesquisadoras quanto de seu gênero na forma como as pessoas entrevistadas designam sua raça/cor. Apresentamos algumas hipóteses provisórias para explicação das diferenças encontradas, cuja averiguação dependerá da realização de novas pesquisas.
Política do vivente
Authors: Gadelha Kaciano Barbosa , Silva Francisco Rômulo do Nascimento
Published: September 2022

Resumo Em seu ensaio, Achille Mbembe disserta acerca do modo pelo qual as políticas da inimizade se tornaram a versão mais sofisticada do exercício do poder e da dominação gestados pelo projeto moderno do Ocidente, exacerbando-se nas novas tecnologias da guerra, na fragmentação digital dos extrativismos contemporâneos, na desumanização em favor da instrumentalização de todas as relações, nos genocídios e hostilidades raciais e étnicas, na devastação do mundo – um processo histórico que se impôs em escala global através do colonialismo e do racismo, aspectos dissimulados da narrativa do humanismo iluminista. Na trilha de pensadores como Édouard Glissant e Frantz Fanon, bem como nas dobras e entranhas da história crítica da modernidade, Mbembe propõe um pensamento de Todo-o-Mundo, uma política do vivente que reorganize as relações em torno do em-comum.
TRAJETÓRIAS SOCIAIS EM ESTRATOS MÉDIOS: FAMÍLIA, ESCOLARIDADE E TRABALHO
Authors: Menezes Vitor Matheus Oliveira de
Published: September 2022

Resumo Este artigo analisa a socialização familiar, considerando a forma pela qual recursos circulam, são acessados e transmitidos pelas relações de parentesco; e as práticas de aprendizado desenvolvidas no seio da esfera familiar, que incidem sobre formas de ver e agir no mundo e terminam por orientar expectativas e comportamentos individuais. Parto de entrevistas realizadas em Salvador para examinar as relações entre parentes, os percursos em instituições educativas, as trajetórias no mercado de trabalho e as autoidentificações de classe. O estudo observou trajetórias marcadas por investimentos que visam alçar os indivíduos para além das características originárias das unidades domésticas. Contudo, os resultados destes investimentos são incertos, como “apostas”, visto a imprevisibilidade de certos fatores, tais como a capacidade de absorção do mercado de trabalho.
Desafíos de la terapia ocupacional en salud mental: reflexiones desde una experiencia de docencia
Authors: Osorio Diana Milena Ramírez , Montaño Jeannette Amanda Méndez
Published: September 2022

Resumen Reflexionar la terapia ocupacional en salud mental desde la práctica docente, con enfoque cualitativo y crítico permite identificar desafíos profesionales en los contextos habituales de las personas y colectivos. Priorizar el contexto clínico para la atención ha condicionado la integralidad y continuidad de los procesos. La terapia ocupacional en salud mental debe transitar además por los contextos habituales, en los que las personas participan en ocupaciones. Este artículo presenta las reflexiones hechas, en torno a los desafíos de la terapia ocupacional en la atención integral en salud mental, desde la práctica docente. Dichas reflexiones parten del uso de técnicas cualitativas de análisis empleadas por las docentes del área psicosocial entre 2013 y 2020, entre las cuales se incluye la revisión y el análisis documental del marco normativo y conceptual, diarios de campo, documentos de sistematización de experiencias, observación participante y espacios académicos de discusión. Se observa que la terapia ocupacional en salud mental en Colombia, se ha estructurado principalmente en contextos clínicos, con enfoque resolutivo que frecuentemente da respuesta a necesidades individuales relacionadas con sintomatología asociada a los trastornos prevalentes; esta institucionalización de las prácticas limita la continuidad de los procesos. Es necesario realizar una aproximación a reflexiones que se vienen dando, en las que se reconoce al terapeuta ocupacional como el profesional que promueve el análisis, la interacción entre sistemas, contextos, personas, poblaciones y ocupaciones; perspectiva que permitiría responder a planteamientos actuales de política; de atención integral e inclusión social. La profesión debe contemplar el abordaje de necesidades ocupacionales subjetivas en los contextos habituales, redimensionando el uso de la ocupación como herramienta para la autonomía e inclusión social.
Does the structure of the test affect the performance of students? Evidences from the Enem (2016)
Authors: Barichello Leonardo , Guimarães Rita Santos , Figueiredo Filho Dalson Britto
Published: September 2022

Abstract This paper analyzes the impact of the position of questions on students’ performance on the National Secondary Education Examination (Enem) in 2016. From a sample of 4,427,790 cases, we calculated the hit rate per question for the different workbooks in the Mathematics and its Technologies test. The results indicate presence of the fatigue effect on the 2016 Enem, that is, the order in which the questions are presented affects the proportion of correct answers, which is diminished as an item is presented closer to the end of the test. The exploratory evidence also suggests that the fatigue effect is manifested in students of both low and high performance. For example, the position of an item reduced the hit rate up to 18%, controlling for performance level. This paper conducts the first empirical evaluation of the fatigue effect during the Enem. The results contribute to the literature on the non-cognitive influences in evaluation, being useful to substantiate more systematic studies on the fatigue effect’s impact on large-scale standardized tests, beyond the case analyzed. At the end, we suggest measures that can mitigate this effect during the Enem.
A formatação da prova afeta o desempenho dos estudantes? Evidências do Enem (2016)
Authors: Barichello Leonardo , Guimarães Rita Santos , Figueiredo Filho Dalson Britto
Published: September 2022

Resumo Este artigo analisa o impacto da posição em que as questões são apresentadas sobre o desempenho dos estudantes no Exame Nacional do Ensino Médio (Enem) no Brasil em 2016. A partir de uma amostra de 4.427.790 casos, calculamos o índice de acerto por questão para os diferentes cadernos de prova da área de Matemática e suas Tecnologias. Os resultados indicam a presença do efeito fadiga na prova do Enem 2016, ou seja, a ordem de apresentação das questões afeta a proporção de respostas corretas, que diminui à medida que o item é apresentado mais próximo do final da prova. As evidências exploratórias também sugerem que o efeito fadiga se manifesta tanto em estudantes de baixo quanto de alto desempenho. Por exemplo, a posição do item reduziu o índice de acerto em até 18 pontos percentuais, controlando pelo nível de desempenho. Este artigo faz a primeira avaliação empírica do efeito fadiga no Enem e os resultados representam uma contribuição para a literatura sobre influências não cognitivas em avaliação e são úteis para fundamentar estudos mais sistemáticos sobre o impacto do efeito fadiga em testes padronizados de larga escala, inclusive para além do caso específico analisado. Ao final, sugerimos medidas que podem mitigar esse efeito no Enem.
Meanings of education in distance learning advertising: from the process paradigm to the product paradigm
Authors: Rodrigues Eduardo Alves , Agustini Cármen L. H.
Published: September 2022

Abstract In this article, based on the theoretical-methodological framework of Discourse Analysis, we analyze advertising pieces that put distance learning (DL) on sale in the market. Such advertisements circulate socially – although not exclusively – in the online form. Our objective was to restore, by means of a discursive and materialist interpretative device, (re)interpretation conditions to the process of producing effects of meanings evocable in and through the referred advertising pieces. This restoration was carried out by focusing on how the meanings of education at stake in DL advertising shift the inscription of (distance) learning, moving it away from the process paradigm and leading it toward the product paradigm. This rendering process produces, as an effect, the projection of (distance) learning to the status of merchandise. By means of our analyses, we show that, as merchandise, DL advertising establishes discourses that aggravate the class struggle in neoliberal capitalist society by means of articulation and discursive transversality that (re)direct DL’s discursive reduction to professionalization, to effortlessness, to instantaneousness, to the digital form and to jobs, configuring DL as the “new normal” of/in education. Because of this discursive practice and its impact on society, the discursive devices operating in DL advertising produce a risk to the emancipation of the subject in and through (distance) learning.
Supervised practice in history courses: a study about Brazil/Portugal
Authors: Noda Marisa , Solé Maria Glória Parra Santos , Cainelli Marlene
Published: September 2022

Abstract The study presented in this article was carried out in 2019 with students from the third year of the History course at the State University of Londrina/Paraná/Brazil, and the students from the Master’s Degree in History Teaching at the University of Minho, in the city of Braga in Portugal, and addressed the meaning of the Supervised Practice for the training of History teachers. The discipline is formed within the field of dialogue between the epistemology of History and teaching procedures based on the science of History. In this text, we chose to explore a questionnaire applied to the two realities with questions that face the meaning of History, of being a History teacher and the experience lived during the implementation of teaching projects in the regencies carried out within public schools in both countries. The research in both institutions took place for two main reasons: first, because we consider that in these institutions there is an improvement in the training of History teachers, translated into a model of Supervised Practice with avant-garde characteristics, whose accomplishment is reflected in research that provokes the perception of the importance of supervised educational practices, and, second, because the experiences translated in the interviews will help understanding this moment as an essential epistemological basis for teacher training.
O estágio supervisionado nos cursos de licenciatura em história: um estudo sobre Brasil/Portugal
Authors: Noda Marisa , Solé Maria Glória Parra Santos , Cainelli Marlene
Published: September 2022

Resumo A investigação que apresentamos neste artigo foi realizada no ano de 2019, junto aos alunos do terceiro ano do curso de licenciatura em história da Universidade Estadual de Londrina (Paraná, Brasil) e do mestrado em ensino de história da Universidade do Minho, na cidade de Braga (Portugal), e abordou o significado do estágio supervisionado para a formação dos professores de história. Defendemos que a disciplina se constitui no campo de diálogo entre a epistemologia da história e os procedimentos de ensino baseados na ciência da história. Neste texto, optamos por explorar um questionário aplicado às duas realidades com questões que dão face ao significado da história, de ser professor de história e da experiência vivenciada durante a implementação dos projetos de ensino nas regências realizadas dentro de escolas de rede pública dos dois países. A pesquisa nas duas instituições deu-se por duas razões principais: primeiro, por considerarmos que nessas instituições há um aprimoramento na formação de professores de história, traduzida por um modelo de estágio supervisionado com características de vanguarda, cuja realização se reflete em pesquisas que provocam a percepção da importância das práticas educativas supervisionadas; e, segundo, pelo fato de as experiências traduzidas nas entrevistas auxiliarem na compreensão deste momento como base epistemológica imprescindível para formação de professores.
Normalidad, rendimiento y subjetividad en el contexto escolar chileno: análisis desde la gubernamentalidad
Authors: Yuing-Alfaro Tuillang , Santis Marcela Apablaza
Published: September 2022

Resumen En este artículo se revisan algunos elementos que intervienen en la conformación de la subjetividad de los estudiantes al interior del contexto escolar chileno. El objetivo, en ese sentido, es bosquejar algunas hipótesis en torno al impacto del plano normativo en el perfil del estudiante cuando está confrontado a la dimensión del rendimiento escolar. Para este fin se toma como marco de análisis la noción de gubernamentalidad desarrollada por Michel Foucault (2006), que atiende a la puesta en forma de un marco administrativo dirigido a la esfera de la población en complemento con la dimensión individual. De este modo, y teniendo a la base la experiencia chilena, se analizan algunos dispositivos del cotidiano escolar que, al alero de un marco normativo basado en principios de inclusión, no discriminación y al mismo tiempo de modernización en sus mecanismos de gestión, actúan como campo de regulación y administración de aquellas conductas que, por su desajuste frente a las expectativas de rendimiento educativo, se vuelven objetos de patologización, intervención, corrección y medicalización. El lugar de la psicometría y su relación con el individuo como célula de análisis, la pertinencia de los saberes psi, como enclave clínico-terapéutico al interior de la trama escolar son, entre otros, algunos de los resultados preliminares que contribuyen este análisis.
Understanding and Self-understanding: the Brazilian educational field within an itinerary of readings from Pierre Bourdieu
Authors: Catani Denice Barbara
Published: September 2022

Abstract The text renders explicit and analyses an appropriation modality of Pierre Bourdieu’s thinking, as it indicates some fundamental points for studies on the educational area. It refers to the possibilities of understanding inscribed in his sociology regarding the elaboration of scientific knowledge and the field’s determinants, habitus and capitals linked to subjects and their positions. It thus underlines the intimate connection between scientific knowledge and self-knowledge. Among its aims, the text seeks to be useful to young researchers as it shows the modalities of thinking “with Bourdieu” as I remake a case and bring attention to the problems of knowledge production in education, historically and socially. A personal itinerary of readings from the Bourdieu’s oeuvre is built in the form of an essay and using it as a method, highlighting two perspectives that guided choices in different moments. One of them refers to the development of investigations in the history of Brazilian education and the other refers to the research, teaching and intervention work involved in teachers’ training. Given the nature of writing and the conviction that several modes of production around educational studies are possible and desirable, no conclusions are made explicit, but, instead, I propose a multiplicity of questions that unfold from the construction of ideas and from the thinking trajectories undertaken.
Creencias y actitudes de docentes chilenos y españoles al enseñar escritura en la pandemia: un estudio contrastivo
Authors: Ibáñez Ester Trigo , Azagra Marcela Jarpa , Landero Rocío Maraver
Published: September 2022

Resumen Las investigaciones nacionales e internacionales han permitido conocer qué y cómo los estudiantes y profesores enfrentan la enseñanza de la escritura. No obstante, la pandemia de la COVID-19 ha generado nuevas necesidades de investigación educativa, como la enseñanza de la escritura en modalidad remota. Así, esta investigación persigue comparar las experiencias y prácticas pedagógicas que un grupo de docentes chilenos y españoles tuvieron durante la enseñanza remota en la pandemia. Se trata de una investigación cualitativa que se afronta desde una perspectiva etnográfica digital y se circunscribe al paradigma sociocrítico. Se ha contado con la participación voluntaria de 20 docentes chilenos y 20 docentes españoles de Educación Primaria que tuvieron que afrontar la docencia en modalidad remota tras la declaración de pandemia en marzo de 2020. Para recabar la información se ha utilizado una entrevista semiestructurada. Los datos obtenidos han sido procesados con el programa de análisis cualitativo NVivo 12. Las respuestas de los docentes participantes evidencian que la pandemia ha marcado un antes y un después en las prácticas pedagógicas en general, y en la enseñanza de la escritura, en particular. No obstante, los docentes chilenos ponen el foco de su preocupación en los estudiantes, mientras que los docentes españoles lo hacen en la formación permanente del profesorado para impartir docencia en modalidad online. En ambos contextos se evidencia la necesidad de formación para la enseñanza telemática de la escritura.
Enhancing the Context-Enhanced Additive Heuristic with Precedence Constraints
Authors: Cai Dunbo , Hoffmann Joerg , Helmert Malte
Published: September 2022

Recently, Helmert and Geffner proposed the context-enhanced additive heuristic, where fact costs are evaluated relative to context states that arise from achieving first a pivot condition of each operator. As Helmert and Geffner pointed out, the method can be generalized to consider contexts arising from arbitrary precedence constraints over operator conditions instead. Herein, we provide such a generalization. We extend Helmert and Geffner's equations, and discuss a number of design choices that arise. Drawing on previous work on goal orderings, we design a family of methods for automatically generating precedence constraints. We run large-scale experiments, showing that the technique can help significantly, depending on the choice of precedence constraints. We shed some light on this by profiling the behavior of all possible precedence constraints, using a sampling technique.
Incremental Policy Generation for Finite-Horizon DEC-POMDPs
Authors: Amato Christopher , Dibangoye Jilles , Zilberstein Shlomo
Published: September 2022

Solving multiagent planning problems modeled as DEC-POMDPs is an important challenge.  These models are often solved by using dynamic programming, but the high resource usage of current approaches results in limited scalability.  To improve the efficiency of dynamic programming algorithms, we propose a new backup algorithm that is based on a reachability analysis of the state space.  This method, which we call incremental policy generation, can be used to produce an optimal solution for any possible initial state or further scalability can be achieved by making use of a known start state. When incorporated into the optimal dynamic programming algorithm, our experiments show that planning horizon can be increased due to a marked reduction in resource consumption. This approach also fits nicely with approximate dynamic programming algorithms.  To demonstrate this, we incorporate it into the state-of-the-art PBIP algorithm and show significant performance gains.  The results suggest  that the performance of other dynamic programming algorithms for DEC-POMDPs could be similarly improved by integrating the incremental policy generation approach.
Navigation Planning in Probabilistic Roadmaps with Uncertainty
Authors: Kneebone Michael , Dearden Richard
Published: September 2022

Probabilistic Roadmaps (PRM) are a commonly used class of algorithms for robot navigation tasks where obstacles are present in the environment. We examine the situation where the obstacle positions are not precisely known. A subset of the edges in the PRM graph may possibly intersect the obstacles, and as the robot traverses the graph it can make noisy observations of these uncertain edges to determine if it can traverse them or not. The problem is to traverse the graph from an initial vertex to a goal without taking a blocked edge, and to do this optimally the robot needs to consider the observations it can make as well as the structure of the graph. In this paper we show how this problem can be represented as a POMDP. We show that while too large to be solved with exact methods, approximate point based methods can provide a good quality solution. While feasible for smaller examples, this approach isn't scalable. By exploiting the structure in the belief space, we can construct an approximate belief-space MDP that can be solved efficiently using recent techniques in MDP planning. We then demonstrate that this gives near optimal results in most cases while achieving an order of magnitude speed-up in policy generation time.
Lower Bounding Klondike Solitaire with Monte-Carlo Planning
Authors: Bjarnason Ronald , Fern Alan , Tadepalli Prasad
Published: September 2022

Despite its ubiquitous presence, very little is known about the odds of winning the simple card game of Klondike Solitaire. The main goal of this paper is to investigate the use of probabilistic planning to shed light on this issue. Unfortunatley, most probabilistic planning techniques are not well suited for Klondike due to the difficulties of representing the domain in standard planning languages and the complexity of the required search. Klondike thus serves as an interesting addition to the complement of probabilistic planning domains. In this paper, we study Klondike using several sampling-based planning approaches including UCT, hindsight optimization, and sparse sampling, and establish lower bounds on their performance. We also introduce novel combinations of these approaches and evaluate them in Klondike. We provide a theoretical bound on the sample complexity of a method that naturally combines sparse sampling and UCT. Our results demonstrate that there is a policy that within tight confidence intervals wins over 35% of Klondike games. This result is the first reported lower bound of an optimal Klondike policy.
hm(P) = h1(Pm): Alternative Characterisations of the Generalisation From hmax To hm
Authors: Haslum Patrik
Published: September 2022

The hm (m = 1 ...) family of admissible heuristics for STRIPS planning with additive costs generalise the hmax heuristic, which results when m = 1. We show that the step from h1 to hm can be made by changing the planning problem instead of the heuristic function. This furthers our understanding of the hm heuristic, and may inspire application of the same generalisation to admissible heuristics stronger than hmax. As an example, we show how it applies to the additive variant of hm obtained via cost splitting.
Action Elimination and Plan Neighborhood Graph Search: Two Algorithms for Plan Improvement
Authors: Nakhost Hootan , Müller Martin
Published: September 2022

Compared to optimal planners, satisficing planners can solve much harder problems but may produce overly costly and long plans. Plan quality for satisficing planners has become increasingly important. The most recent planning competition IPC-2008 used the cost of the best known plan divided by the cost of the generated plan as an evaluation metric. This paper proposes and evaluates two simple but effective methods for plan improvement: Action Elimination improves an existing plan by repeatedly removing sets of irrelevant actions. Plan Neighborhood Graph Search finds a new, shorter plan by creating a plan neighborhood graph PNG(π) of a given plan π, and then extracts a shortest path from PNG(π). Both methods are implemented in the Aras postprocessor and are empirically shown to improve the result of several planners, including the top four planners from IPC-2008, under competition conditions.
Forward-Chaining Partial-Order Planning
Authors: Coles Amanda , Coles Andrew , Fox Maria , Long Derek
Published: September 2022

Over the last few years there has been a revival of interest in the idea of least-commitment planning with a number of researchers returning to the partial-order planning approaches of UCPOP and VHPOP. In this paper we explore the potential of a forward-chaining state-based search strategy to support partial-order planning in the solution of temporal-numeric problems. Our planner, POPF, is built on the foundations of grounded forward search, in combination with linear programming to handle continuous linear numeric change. To achieve a partial ordering we delay commitment to ordering decisions, timestamps and the values of numeric parameters, managing sets of constraints as actions are started and ended. In the context of a partially ordered collection of actions, constructing the linear program is complicated and we propose an efficient method for achieving this. Our late-commitment approach achieves flexibility, while benefiting from the informative search control of forward planning, and allows temporal and metric decisions to be made - as is most efficient - by the LP solver rather than by the discrete reasoning of the planner. We compare POPF with the approach of constructing a sequenced plan and then lifting a partial order from it, showing that our approach can offer improvements in terms of makespan, and time to find a solution, in several benchmark domains.
The Joy of Forgetting: Faster Anytime Search via Restarting
Authors: Richter Silvia , Thayer Jordan , Ruml Wheeler
Published: September 2022

Anytime search algorithms solve optimisation problems by quickly finding a (usually suboptimal) first solution and then finding improved solutions when given additional time. To deliver an initial solution quickly, they are typically greedy with respect to the heuristic cost-to-go estimate h. In this paper, we show that this low-h bias can cause poor performance if the greedy search makes early mistakes. Building on this observation, we present a new anytime approach that restarts the search from the initial state every time a new solution is found. We demonstrate the utility of our method via experiments in PDDL planning as well as other domains, and show that it is particularly useful for problems where the heuristic has systematic errors.
Improving Determinization in Hindsight for On-line Probabilistic Planning
Authors: Yoon Sungwook , Ruml Wheeler , Benton J. , Do Minh
Published: September 2022

Recently, "determinization in hindsight" has enjoyed surprising success in on-line probabilistic planning. This technique evaluates the actions available in the current state by using non-probabilistic planning in deterministic approximations of the original domain. Although the approach has proven itself effective in many challenging domains, it is computationally very expensive. In this paper, we present three significant improvements to help mitigate this expense. First, we use a method for detecting potentially useful actions, allowing us to avoid estimating the values of unnecessary ones. Second, we exploit determinism in the domain by reusing relevant plans rather than computing new ones. Third, we improve action evaluation by increasing the chance that at least one determin- istic plan reaches a goal. Taken together, these improvements allow determinization in hindsight to scale significantly better on large or mostly-deterministic problems.
Iterative Learning of Weighted Rule Sets for Greedy Search
Authors: Xu Yuehua , Fern Alan , Yoon Sungwook
Published: September 2022

Greedy search is commonly used in an attempt to generate solutions quickly at the expense of completeness and optimality. In this work, we consider learning sets of weighted action-selection rules for guiding greedy search with application to automated planning. We make two primary contributions over prior work on learning for greedy search. First, we introduce weighted sets of action-selection rules as a new form of control knowledge for greedy search. Prior work has shown the utility of action-selection rules for greedy search, but has treated the rules as hard constraints, resulting in brittleness. Our weighted rule sets allow multiple rules to vote, helping to improve robustness to noisy rules. Second, we give a new iterative learning algorithm for learning weighted rule sets based on RankBoost, an efficient boosting algorithm for ranking. Each iteration considers the actual performance of the current rule set and directs learning based on the observed search errors. This is in contrast to most prior approaches, which learn control knowledge independently of the search process. Our empirical results have shown significant promise for this approach in a number of domains.
Incrementally Solving STNs by Enforcing Partial Path Consistency
Authors: Planken Léon , De Weerdt Mathijs , Yorke-Smith Neil
Published: September 2022

Efficient management and propagation of temporal constraints is important for temporal planning as well as for scheduling. During plan development, new events and temporal constraints are added and existing constraints may be tightened; the consistency of the whole temporal network is frequently checked; and results of constraint propagation guide further search. Recent work shows that enforcing partial path consistency provides an efficient means of propagating temporal information for the popular Simple Temporal Network (STN). We show that partial path consistency can be enforced incrementally, thus exploiting the similarities of the constraint network between subsequent edge tightenings. We prove that the worst-case time complexity of our algorithm can be bounded both by the number of edges in the chordal graph (which is better than the previous bound of the number of vertices squared), and by the degree of the chordal graph times the number of vertices incident on updated edges. We show that for many sparse graphs, the latter bound is better than that of the previously best-known approaches. In addition, our algorithm requires space only linear in the number of edges of the chordal graph, whereas earlier work uses space quadratic in the number of vertices. Finally, empirical results show that when incrementally solving sparse STNs, stemming from problems such as Hierarchical Task Network planning, our approach outperforms extant algorithms.
Classical Planning in MDP Heuristics: with a Little Help from Generalization
Authors: Kolobov Andrey , Mausam . , Weld Daniel
Published: September 2022

Computing a good policy in stochastic uncertain environments with unknown dynamics and reward model parameters is a challenging task. In a number of domains, ranging from space robotics to epilepsy management, it may be possible to have an initial training period when suboptimal performance is permitted. For such problems it is important to be able to identify when this training period is complete, and the computed policy can be used with high confidence in its future performance. A simple principled criteria for identifying when training has completed is when the error bounds on the value estimates of the current policy are sufficiently small that the optimal policy is fixed, with high probability. We present an upper bound on the amount of training data required to identify the optimal policy as a function of the unknown separation gap between the optimal and the next-best policy values. We illustrate with several small problems that by estimating this gap in an online manner, the number of training samples to provably reach optimality can be significantly lower than predicted offline using a Probably Approximately Correct framework that requires an input epsilon parameter.
Computer-Aided Algorithm Design: Automated Tuning, Conﬁguration, Selection, and Beyond
Authors: Hoos Holger
Published: September 2022

In this talk, I will introduce computer-aided algorithm design and discuss its main ingredients: design patterns, which provide ways of structuring potentially large spaces of candidate algorithms, and meta-algorithmic optimisation procedures, which are used for ﬁnding good designs within these spaces. After explaining how this algorithm design approach differs from and complements related approaches in program synthesis, genetic programming and so-called hyperheuristics, I will illustrate its success using examples from our own work in SAT-based software veriﬁcation (Hutter et al. 2007), timetabling (Chiarandini, Fawcett, and Hoos 2008) and mixed integer programming (Hutter, Hoos, and Leyton-Brown 2010). Furthermore, I will argue why this approach can be expected to be particularly useful and effective for building better solvers for rich and diverse classes of combinatorial problems, such as planning and scheduling. Finally, I will outline out how programming by optimisation — a design paradigm that emphasises the automated construction of performance-optimised algorithm by means of searching large spaces of alternative designs — has the potential to transform the design of high-performance algorithm from a craft that is based primarily on experience and intuition into a principled and highly effective engineering effort.
Robotic Agents for Disaster Response Robotics
Authors: Nardi Daniele
Published: September 2022

In the ﬁrst part of the talk, I brieﬂy overview the state of the art in the ﬁeld of disaster response robotics. In the second part of the talk, I present some of the research we developed at Sapienza Univ. of Rome, also in collaboration with the Italian Firemen Department. Speciﬁcally, I describe some results in Distributed Situation Assessment, Action Planning and Monitoring, Context-based Design of intelligent robotic agents, Multi-robot Teams for disaster response robotics, and Performance Evaluation Metrics for intelligent robotic agents. Throughout the discussion, I focus on several open challenges that need to be addressed to provide effective solutions for Disaster Response Robotics.
The Scanalyzer Domain: Greenhouse Logistics as a Planning Problem
Authors: Helmert Malte , Lasinger Hauke
Published: September 2022

We introduce the Scanalyzer planning domain, a domain for classical planning which models the problem of automatic greenhouse logistic management. At its mathematical core, the Scanalyzer domain is a permutation problem with striking similarities to common search benchmarks such as Rubik's Cube or TopSpin. At the same time, it is also a real application domain, and efficient algorithms for the problem are of considerable practical interest. The Scanalyzer domain was used as a benchmark for sequential planners at the last International Planning Competition. The competition results show that domain-independent automated planners can find solutions of comparable quality to those generated by specialized algorithms developed by domain experts, while being considerably more flexible.
When Policies Can Be Trusted: Analyzing a Criteria to Identify Optimal Policies in MDPs with Unknown Model Parameters
Authors: Brunskill Emma
Published: September 2022

Computing a good policy in stochastic uncertain environments with unknown dynamics and reward model parameters is a challenging task. In a number of domains, ranging from space robotics to epilepsy management, it may be possible to have an initial training period when suboptimal performance is permitted. For such problems it is important to be able to identify when this training period is complete, and the computed policy can be used with high confidence in its future performance. A simple principled criteria for identifying when training has completed is when the error bounds on the value estimates of the current policy are sufficiently small that the optimal policy is fixed, with high probability. We present an upper bound on the amount of training data required to identify the optimal policy as a function of the unknown separation gap between the optimal and the next-best policy values. We illustrate with several small problems that by estimating this gap in an online manner, the number of training samples to provably reach optimality can be significantly lower than predicted offline using a Probably Approximately Correct framework that requires an input epsilon parameter.
Markov Decision Processes with Ordinal Rewards: Reference Point-Based Preferences
Authors: Weng Paul
Published: September 2022

In a standard Markov decision process (MDP), rewards are assumed to be precisely known and of quantitative nature. This can be a too strong hypothesis in some situations. When rewards can really be modeled numerically, specifying the reward function is often difficult as it is a cognitively-demanding and/or time-consuming task. Besides, rewards can sometimes be of qualitative nature as when they represent qualitative risk levels for instance. In those cases, it is problematic to use directly standard MDPs and we propose instead to resort to MDPs with ordinal rewards. Only a total order over rewards is assumed to be known. In this setting, we explain how an alternative way to define expressive and interpretable preferences using reference points can be exploited.
Automatic Construction of Efficient Multiple Battery Usage Policies
Authors: Fox Maria , Long Derek , Magazzeni Daniele
Published: September 2022

Efficient use of multiple batteries is a practical problem with wide and growing application. The problem can be cast as a planning problem. We describe the approach we have adopted to modelling and solving this problem, seen as a Markov Decision Problem, building effective policies for battery switching in the face of stochastic load profiles. Our solution exploits and adapts several existing techniques from the planning literature and leads to the construction of policies that significantly outperform those that are currently in use and the best published solutions to the battery management problem. We achieve solutions that achieve more than 99\% efficiency compared with the theoretical limit and do so with far fewer battery switches than existing policies. We describe the approach in detail and provide empirical evaluation demonstrating its effectiveness.
Planning for Loosely Coupled Agents Using Partial Order Forward-Chaining
Authors: Kvarnström Jonas
Published: September 2022

We investigate a hybrid between temporal partial-order and forward-chaining planning where each action in a partially ordered plan is associated with a partially defined state. The focus is on centralized planning for multi-agent domains and on loose commitment to the precedence between actions belonging to distinct agents, leading to execution schedules that are flexible where it matters the most. Each agent, on the other hand, has a sequential thread of execution reminiscent of forward-chaining. This results in strong and informative agent-specific partial states that can be used for partial evaluation of preconditions as well as precondition control formulas used as guidance. Empirical evaluation shows the resulting planner to be competitive with TLplan and TALplanner, two other planners based on control formulas, while using a considerably more expressive and flexible plan structure.