Learning robot policies using a high-level abstraction persona-behaviour simulator

2019 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting /republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other worksCollecting data in Human-Robot Interaction for training learning agents might be a hard task to accomplish. This is especially true when the target users are older adults with dementia since this usually requires hours of interactions and puts quite a lot of workload on the user. This paper addresses the problem of importing the Personas technique from HRI to create fictional patients’ profiles. We propose a Persona-Behaviour Simulator tool that provides, with high-level abstraction, user’s actions during an HRI task, and we apply it to cognitive training exercises for older adults with dementia. It consists of a Persona Definition that characterizes a patient along four dimensions and a Task Engine that provides information regarding the task complexity. We build a simulated environment where the high-level user’s actions are provided by the simulator and the robot initial policy is learned using a Q-learning algorithm. The results show that the current simulator provides a reasonable initial policy for a defined Persona profile. Moreover, the learned robot assistance has proved to be robust to potential changes in the user’s behaviour. In this way, we can speed up the fine-tuning of the rough policy during the real interactions to tailor the assistance to the given user. We believe the presented approach can be easily extended to account for other types of HRI tasks; for example, when input data is required to train a learning algorithm, but data collection is very expensive or unfeasible. We advocate that simulation is a convenient tool in these cases.Peer ReviewedPostprint (author's final draft

Deciding the sale of a life policy in the viatical market: Implications on individual welfare

In this paper, we present an economic model that allows a terminally ill policy-holder to decide whether or not to sell (part of) the policy in the viatical settlement market. The viatical settlement market emerged in the late 1980s in response to the AIDS epidemic. Nowadays it is part of the large US market in life settlements. The policies traded in the viatical market are those of terminally ill policyholders expected to die within the next two years. The model is discrete and considers only the next two periods (years), since this is the max- imum remaining lifetime of the policyholder. The decisor has an initial wealth and has to share it between his own consumption and the bequests left to his heirs. We rst introduce the expected utility function of our decisor and then use dynamic programming to deduce the strategy that gives higher utility (not selling/selling (part of) the policy at time zero/selling (part of) the policy at time one). The optima depends on the value of the viaticated policy and on some personal parameters of the individual. We nd an analitical expression for the optimal strategy and perform a sensitivity analysis.expected utility, viatical settlement, dynamic programming

Influence of pre-existing martensite on the wear resistance of metastable austenitic stainless steels

The effect of pre-existing martensite on the sliding wear behavior of a commercial metastable austenitic stainless steel was investigated. Two different steel conditions were considered: annealed (with a fully austenitic microstructure) and cold rolled, consisting of mixtures of austenite and martensite. Wear tests were carried out using ball on disc technique at constant velocity and different sliding distances. Correlation between microstructure and wear mechanisms was performed by X-ray diffraction, electron back-scattered diffraction and focus ion beam. Results show that wear resistance decreases at increasing the amount of pre-existing martensite. In this sense, more strain-induced martensite developed for cold rolled samples, hardening the surface and consequently reducing wedge formation, which induced material removal from the surface. The detailed analysis of the wear track demonstrated the formation of an ultrafine-grain layer just below the surface, not only for annealed but also for cold rolled steel.Peer ReviewedPreprin

Robot-aided cloth classification using depth information and CNNs

The final publication is available at link.springer.comWe present a system to deal with the problem of classifying garments from a pile of clothes. This system uses a robot arm to extract a garment and show it to a depth camera. Using only depth images of a partial view of the garment as input, a deep convolutional neural network has been trained to classify different types of garments. The robot can rotate the garment along the vertical axis in order to provide different views of the garment to enlarge the prediction confidence and avoid confusions. In addition to obtaining very high classification scores, compared to previous approaches to cloth classification that match the sensed data against a database, our system provides a fast and occlusion-robust solution to the problem.Peer ReviewedPostprint (author's final draft

Sobre os porquês do pluralismo em economia: aproximações de uma alternativa historicista

Amidst the economists that are concerned about the method, it is common to make reference on the subject of a new economic methodology. It was from the deception and the abandon of the search toward a unique criterion to give scientific status to research programmes that this new movement came into being. Therefore, among the studies within this innovative trend there’re many patterns of pluralism. All of them reveal different perspectives that can justify the diversity of more or less substitute research programmes within economics. This paper suggests that the ideas of a hermeneutics philosophy’s founding father Wilhelm Dilthey offers an epistemological option to legitimate this state of affairs inside economic science. His thought is chiefly presented as an alternative for Bruce Caldwell’s and Sheila Dow’s pluralisms.history of economic thought, pluralism, hermeneutics, Dilthey

Um lugar, um tempo e um sistema de economia: ensaio interpretativo sobre o surgimento do institucionalismo norte-americano de Thorstein Veblen

This paper intends to present a particular analysis of Thorstein Veblen’s work. In this fashion, we have identified a central idea that commands his oeuvre: the non-teleologism. In addition, as a another central objective, the study pretends to establish a relationship between this hard core principle and the evolution of the ideological and political dichotomy between conservatism and reformism through United States history. For accomplish that, we use an epistemological justification that stands on the Strong Programme of Sociology of Science arguments. They suggest a relation, in a cause and consequence way, connecting the social context and the structures of scientific theories. Finally, this allows the suggestion of a general meaning for the Thorstein Veblen’s system of institutional economics.history of economic thought, Thorstein Veblen, American institutionalism, teleology

Teoria integradora sobre o modo de ação de Quinclorac : revisão de literatura

Quinclorac is a systemic herbicide absorbed by germinating seeds, roots and leaves of seedlings. It is a selective compound for crops such as rice, canola, barley, corn, sorghum, and pasture. Quinclorac can be used to control various monocots and dicotyledonous weed species. The biochemical function of this herbicide in the plant has intrigued scientists for nearly four decades. The objectives of this review are to present evidence of three hypotheses on the biochemical functioning of quinclorac and to propose an integrative mode of action. The first theory on the mode of action of quinclorac is supported by evidence of inhibition of incorporation of C14-glucose into cellulose and hemicellulose, thus, affecting the cell wall synthesis. The second hypothesis suggests that quinclorac acts as an auxin in broadleaved weed species. In grass species, however, this herbicide appears to stimulate the activity of the 1-aminocyclopropane-1-carboxylate synthase enzyme and, subsequently, to increase the ethylene production; also, it seems to increase the cyanide acid content to phytotoxic levels. A third hypothesis to explain the harmful effect in some plant species is the formation of reactive oxygen species (ROS). Apparently, these processes are not mutually exclusive; therefore, an integrative theory for the action of quinclorac is suggested. It is theorized that the aforementioned biochemical activities are interconnected and can be the phytotoxic backbone to explain the herbicidal effect depending on the plant species and the plant growth stage, among other factors.O quinclorac é um herbicida sistêmico absorvido por sementes em germinação, raízes e folhas de plântulas. Ele é um produto seletivo para as culturas de arroz, canola, cevada, milho, pastagens e sorgo. Ele pode ser utilizado no controle de diversas plantas daninhas dicotiledôneas e monocotiledôneas. O funcionamento bioquímico desse herbicida na planta tem intrigado os cientistas por quase duas décadas. Os objetivos desta revisão foram apresentar evidências de três hipóteses sobre o funcionamento bioquímico do quinclorac e, a partir das evidências existentes, propor um modo de ação integrador. A primeira teoria sobre o modo de ação do quinclorac é apoiada por evidências de inibição da incorporação de glicose em celulose e em hemiceluloses, afetando assim a síntese de parede celular. A segunda hipótese sugere que o quinclorac atua como auxina sintética em espécies dicotiledôneas. Em espécies gramíneas, todavia, sua ação parece envolver o estímulo da atividade da enzima ácido 1-carboxílico-1-aminociclopropano sintase e o aumento posterior da produção de etileno e, principalmente, cianeto em níveis fitotóxicos. Uma terceira hipótese evidencia que a ação do quinclorac em algumas espécies depende da formação de espécies reativas de oxigênio (ROS). Aparentemente esses processos não são excludentes, por isso é proposta uma teoria integradora para ação do quinclorac. Teoriza-se que as atividades bioquímicas citadas constituem o fundamento da ação desse herbicida e que a manifestação de determinada rota depende das espécies vegetais e dos estágios de desenvolvimento da planta, entre outros fatores

Uso potencial de aminoácidos não-proteinogênicos como aleloquímicos

From existing amino acids, twenty are directly involved in the formation of proteins. The others are known as non- proteinogenic amino acids (NPAA). The NPAA have different functions, including anti-herbivory activity, antimicrobial, protection from stress, cell signaling, nitrogen storage, as toxins against invertebrates and vertebrates and as allelochemicals. Plants are able to release these metabolites in the soil, which may influence the growth and development of neighboring plants, both positively and negatively. The objective of this review is to describe the chemical characteristics, the allelopathic potential and selectivity for crops of non-proteinogenic amino acids m-tyrosine, L-DOPA, methionine sulfoximine and azetidine. Dos aminoácidos existentes, vinte estão envolvidos diretamente na formação de proteínas. Os demais são conhecidos como aminoácidos não-proteinogênicos (AANP). Os AANP possuem diferentes funções, incluindo atividade anti-herbivoria, antimicrobiana, proteção contra o estresse, sinalização celular, armazenamento de nitrogênio, como toxinas contra invertebrados e vertebrados e, também, como aleloquímicos. As plantas são capazes de liberar esses metabólitos no solo, os quais podem influenciar o crescimento e desenvolvimento de plantas vizinhas, tanto positiva como negativamente. O objetivo dessa revisão é descrever as características químicas, o potencial alelopático e a seletividade para culturas dos aminoácidos não-proteinogênicos m-tirosina, L-DOPA, metionina sulfoximina e azetidino.