Navegando por Assunto "Simetria"

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Acesso aberto (Open Access)
Aplicação da teoria de grupos magnéticos para guias de onda e cavidades ressonantes com meios magnéticos
(Universidade Federal do Pará, 2014-08-27) BEIRÃO, Antonio Thiago Madeira; DMITRIEV, Victor Alexandrovich; http://lattes.cnpq.br/3139536479960191
In this paper we apply the theory of magnetic groups in cross sections of waveguides square, rectangular and circular filled with ferrite or semiconductor material with different types of magnetization. These wave guides are structures used in microwave technology as phase shifters, cut-off switches and insulators. Similarly as done in waveguides with different symmetries, were analyzed and classified also resonant cavities with cubic and cylindrical paralelepípeda geometries using group theory magnetic. Considering waveguide sections with four doors and using group theory methods calculated to scattering matrix structure for these guides with different Symmetries and are discussed some of its properties. Furthermore, scattering matrices obtained TE0n modes are accurate and, from them, were calculated eigenvalues and eigenvectors of matrices. The results serve as theoretical reference to check the accuracy of numerical calculations in structures of waveguides.
Acesso aberto (Open Access)
Ensino de simetria por meio de problematização sociocultural
(Universidade Federal do Pará, 2017-10-11) MARTINS, Jeová Pereira; MENDES, Iran Abreu; http://lattes.cnpq.br/4490674057492872; https://orcid.org/0000-0001-7910-1602
The teaching of mathematics in Basic Education deserves special attention from teachers and field researchers, since it has as one of its functions the integral formation of the student in what concerns to the mathematical knowledge that it needs. This work proposes a way of promoting this training at the fundamental level and aims to analyze and discuss the graphical composition structures of the artifacts made in some sociocultural practices, in which geometric patterns were evidenced that show matrices of various Symmetry cases that can be explored pedagogically in the math classes in the final years of Elementary School. It is a qualitative research that has as its central focus the teaching of symmetry of reflection, rotation, translation and sliding reflection, from the graphical composition structure of artifacts originating from some cultures. The data were obtained through empirical and bibliographical research and analyzed according to the ideas of Mendes (2014), Farias and Mendes (2014), Lévi-Strauss (2012) and the mathematics NCPs (1997). The results point to a strong connection between the Symmetry of the final years of Elementary School and the artifacts studied, which may favor the teaching and learning of this subject in a more effective and meaningful way for the students. Finally, we elaborate proposals of Basic Units of Problematization (UBP) as didactic subsidies to be incorporated by the teacher of mathematics in the teaching of Symmetry in the final years of Elementary School.
Acesso aberto (Open Access)
Estratégias de modelagem de Go/No-go e verificação de sua necessidade para ocorrência de simetria em macacos-prego (Cebus apella)
(Universidade Federal do Pará, 2010-01-08) BORGES, Rubilene Pinheiro; SOUZA, Carlos Barbosa Alves de; http://lattes.cnpq.br/1264063598919201
The learning of bidirectional conditional relations (symmetry) has rarely been demonstrated in non-human. Recently, three studies presented positive data from behavioral repertoires of symmetry in pigeons. These studies indicated some variables as possible determinants of the emergence of symmetry: 1) Intermixed training of arbitrary and identity relations at the same time and with the same set of stimuli, 2) Non-exposition to prior training of any kind of relationship with same stimuli, and 3) The use of the successive conditional discrimination (Go/No-go). This study aimed to determine the need for the use of Go/No-go, using the other variables (intermixed training and no prior exposure), to obtain the emergence of symmetry. This study evaluated in two capuchin monkeys (Cebus apella) the learning of arbitrary and identity relations of stimuli presented in the same experimental session and the emergence of symmetry, using two procedures. One subject (M18) was trained in Go/No-go task with mixed arbitrary and identity trials, with the same set of stimuli. The subject went through two Go/No-go training that have not been successful in establishing conditional control. Another subject (M27) was trained in a 0-delayed matching-to-sample task with mixed arbitrary and identity trials, with the same set of stimuli too. This second procedure aimed to determine the need to use the procedure Go/No-go to obtain the emergence of symmetry. Training sessions were composed of eight identity trials (four relations) and eight arbitrary trials (two relations), presented in random sequence. All trials had three choices as comparisons. Subsequently, M27 was submitted to three tests (all of the trials had programmed reinforcement). The intermixed baseline training (identity and arbitrary) occurred in 14 sessions. The first test of symmetry was a session of eight trials for each of the four relations of identity, two arbitrary, and two test trials in a total of 64 trials, and the performance criterion was seven correct trials out of eight for each relation. M27 had 2 errors in a identity relation and reached the criterion for all the others, including those of symmetry. To determine whether there was a consistency of stimulus control, the second test was made in which the choices between the comparisons could no longer be conditional to the model, since was used one single new stimulus as sample at all time in both baseline and test trials. M27 made three errors global. This result may indicate that some kind of unprogrammed stimulus control, developed: as the same two pairs of stimuli alternated in the S- function in all trials, M27 may have learned to reject the two pairs of stimuli independently of the sample presented. In order to verify if indeed there was no control for selection according to the sample, it was ran a test with only two comparisons with the same settings of the first test. M27 made six errors in 32 identity baseline trials, six in 16 arbitrary trials and six in the 16 symmetry trials. The correct responses were therefore above chance level, which partly confirms the hypothesis above and may indicate the presence of a mixed stimulus control between conditional and discriminative stimuli for comparison.
Acesso aberto (Open Access)
Laboratório de etnomatemática da Amazônia Tocantina
(Universidade Federal do Pará, 2021-04-09) VILHENA, Daniela Gonçalves; BARROS, Osvaldo dos Santos; http://lattes.cnpq.br/8886478452699437
When it comes to Teaching Mathematics in riverside spaces located in the city of Igarapé- Mirí-PA, it is faced with numerous difficulties that imply students' performance, for example: the lack of adequate didactic materials and motivating themes; the restricted access of students, due to lack of mobility and the distances between their homes and the school, in addition to the precarious conditions of these spaces. With regard to didactic resources, the main instrument used by teachers, in their teaching practice, is still the textbook. We understand, then, that the elaboration and use of concrete and manipulable materials, adequate to the students' learning needs are important alternatives to riverside schools, since they can be easily related to the experiences of these students. With this in mind, this dissertation aims to create an Ethnomathematics Laboratory in the Tocantina Amazon, which is a space for experimenting with school content related to the daily practices of students living in riverside environments. The riverside school needs spaces that promote the understanding of mathematical concepts and their relationship with instruments and daily practices and, in this sense, teaching laboratories fulfill this role. Thus, when we interact with riverside practices such as: fishing, handling and extraction of açaí, construction of houses and boats, in addition to the making and manipulation of instruments that assist in these practices, we are faced with opportunities to learn mathematics from the perspective of Ethnomathematics Education.And so, looking at the mathematical content from the traditional practices of the riverside communities, we propose to address the fundamental concepts of symmetry and proportionality to develop teaching materials. Thus, the work was developed based on the assumptions described by Vergani, when describing an ethical strategy to stimulate individual and socio-cultural development, D'Ambrósio when he portrays an Ethnomathematics from the point of view of the student's know-how, as well as the experience in socio-culturally differentiated environments and Bishop, who portrays mathematical enculturation, teaching mathematics from a cultural perspective. As a didactic product, result of this research, we propose the composition of a catalog with several activities developed for schools in riverside environments, didactic materials and methodological structures organized for the creation of an Ethnomathematics Laboratory in school spaces.
Acesso aberto (Open Access)
Punição: uma replicação sistemática de skinner (1938)
(Universidade Federal do Pará, 2015-03-06) FIGUEIRA, Renata Almeida; MAYER, Paulo César Morales; http://lattes.cnpq.br/5360949596306254; CARVALHO NETO, Marcus Bentes de; http://lattes.cnpq.br/7613198431695463
Skinner (1938) produced a set of data that led him to conclude the effects of punishment on the response probability would be only indirect. In the main experiment conducted at the time, the initial suppressive effects of punishment (“bar slap”) disappeared after the second session of extinction. This data is still used as a proof in favor of asymmetric interpretations of punishment. The present study is a systematic replication of Skinner (1938) with four manipulations: (a) use of electric shock as aversive stimulus; (b) adoption of 10 sessions in the baseline; (c) the adoption of five extinction sessions; (d) introduction of a yoked group with non-contingent shock. Two experiments were conducted, A and B. In Experiment A, 20 rats were divided into two groups, punished group (APUN) and control group (ACON). The rats were submitted to a training session to the feeder and to lever-press shaping session followed by three sessions of FI- 4min., all lasting 60 min. Later, two sessions of extinction of 120 minutes were carried out. To APUN, superimposed to extinction during the first 10 minutes of the first extinction session, each lever-press produced an electric shock. In Experiment B, 30 rats were divided also into three groups, punished (2PUN), control (2CON) and yoked group (2ACO). The experiment started with a magazine and lever-press training session, followed by ten sessions of FI-4min., all lasting 60 min. Later, the subjects were subject to five sessions of extinction (60 minutes each). To 2PUN, superimposed to extinction during the first 10 minutes of the first session of extinction, each leverpress produced an electric shock. For 2ACO shocks were delivered according to the moment the paired subject from the punished group received it. During each session it was recorded the number of lever pressing per minute contrasting the analysis of Skinner (1938) with Boe and Church (1967) intergroup and intragroup. The results showed that, for all the manipulations performed, there was no response recovery after punishment was discontinued. This suggests it is possible to produce lasting punishment effects provided that certain methodological steps are adopted.
Acesso aberto (Open Access)
Simetria e assimetria entre reforçamento e punição
(Universidade Federal do Pará, 2014-08-22) MAYER, Paulo César Morales; CARVALHO NETO, Marcus Bentes de; http://lattes.cnpq.br/7613198431695463
In Behavior Analysis, consequences play a central role in the explanation of behavior. Reinforcement and punishment are the conceptual tools for the basic behavioral relations between the organism and its environment and to the possible resulting effects as well. Despite consensual that certain consequences may increase behavior probabilities (reinforcement) there is an extensive debate on the role of consequences in suppressing responding and the process involved in it (punishment). Two perspectives prevail on this debate, one termed symmetric, which considers reinforcement and punishment as essentially differing only on the direction of the effect of the probability of responding; and the other, named asymmetric, which, under many aspects considers punishment and reinforcement as intrinsically distinguished phenomena and establishes specific bases to consider each. The present dissertation is an investigation of the experimental bases of the asymmetric position and a proposition of re-dimensioning the debate on the issue of symmetry between reinforcement and punishment. For it, three studies investigated some asymmetric assumptions. Study 1 was a replication of Thorndike (1932, Experiment 71), investigating if the magnitude of the effects of punishment over the responding could be proportional to the ones of reinforcement. Ten college students participated a multiple choice task with the verbal stimuli “Right” and “Wrong” as consequences for the choices. As in the original study, in spite of the choices followed by “Right” having their probability increased, choices followed by “Wrong” continued to occur with probabilities close to the chance level. This data imply unequal effects for each consequence. Study 2 was a replication of Skinner (1938) assessing the extension of the suppressive effects of punishment in comparison to extinction. Six rats were trained for lever pressing on a Fixed Interval (FI) schedule and them submitted to two extinction sessions. Half of the subjects received Hot Air Blasts as consequence for lever pressing (FR1 punishment) during the initial 10 minutes of the first extinction session. Once again, the data reproduced the observed in the original study: although lever press was almost completely suppressed during punishment, responding recovered once the punishment schedule was over and by the end of the second extinction session the total number of responses was the same for both groups of subjects. Study 3 was a replication of Arbuckle and Lattal (1987) evaluating the relation between the behavior suppression produced by punishment and negative reinforcement. Seven white rats served as subjects in an operant chamber equipped with two levers and a self administration drug apparatus. After a training of lever pressing on a Variable Interval (VI) schedule, one of the levers produced pellet as consequence (VI-120s) and intravenous infusions of Histamine (behavioral suppressor) on different VI schedules (maximum value of 15s). Responses on the other lever prevented the histamine infusions (avoidance responding). Histamine effectively suppressed responding however, it was not possible to establish and sustain reliable avoidance responding, even when the contingencies were changed to promote specificvii training of unsignaled (Sidman) avoidance. By discussing the three studies altogether the difficulty of discussing the symmetry between reinforcement and punishment through a single approach arouse. Each study, despite related to the general issue discussed, was designed to answer to different dimensions of the question and the validity of such discussion would be at question. On this scenario an additional essay was written aiming at a conceptual evaluation of the symmetry issue. It is proposed a splitting of the theme under suggested categories, which would help finding new and allegedly more fruitful directions to the debate.
Acesso aberto (Open Access)
Testes de simetria e transitividade em macaco-prego
(Universidade Federal do Pará, 2016-09-29) LIMA, Raquel Leite Castro de; SILVA, Maria Luísa da; http://lattes.cnpq.br/2101884291102108; BRINO, Ana Leda de Faria; http://lattes.cnpq.br/9930065472602966
One way of exploring symbolic behavior and its prerequisites is to teach arbitrary relations with a conditional choice training model, with the purpose of verifying the emergence of new relations between pairs of stimuli used in training. The objective of this study was to test the emergence of symmetry and transitivity in a capuchin monkey, applying before tests teaching conditions used in studies that obtained emergent performance in non-humans. An adult male capuchin monkey from the Experimental School of Primates (NTPC-UFPA) with substantial experience in choice tasks served as subject. In phase 1 of the study, the arbitrary relations AB, B-A and A-C, established in a previous experiment, were retrained in both delayed and simultaneous matching-to-sample (MTS) procedures. In phase 2, the same arbitrary relations A-B, B-A and A-C were trained interpolated with identity trials A-A, B-B and C-C. In phase 3, the reinforcement probability was reduced, in preparation for the testing sessions that would involve trials with no programmed reinforcement. In Phase 4, the emergence of the relations C-A, B-C and C-B were tested. Performance was accessed in terms of the percentage of success across all trials. In training session, the performance criteria were 90% minimum of correct choices and, at most, one error per trained relation. In Phase 1, the subject performed with most precision in the delayed MTS (minimum 75% and maximum 100% of correct choices), probably due to its previous experience with this task; in simultaneous MTS, the performance varied between 64,44% and 97,78% and the number of sessions to criteria was higher than in the simultaneous MTS. In Phase 3, there were 23 sessions to criteria, with an average performance of 89,32% of correct choices in the delayed MTS (6 sessions total) and 87,75% in simultaneous MTS (11 sessions). The subject had difficulties with the simultaneous MTS in which two identical stimuli appeared on the computer screen. This training model induced to errors and was corrected by restricting the location where the sample was presented. In Phase 3, only 7 experimental sessions were enough to criteria, with an average performance of 91,66% correct in 4 sessions of simultaneous MTS and 91,10% in 3 sessions of the delayed MTS. In Phase 4, the tests were negative for the emergence of C-A relations. The average number of correct trials was 23,33%. A drop in the baseline performance and emotional reactions in the subject were observed, probably due to the absence of reinforcement. In B-C test, the average number of correct choices was 71%, demonstrating emergent behavior. C-B relations tests were also negative. Performance on these trials average only 12% of correct choices. The procedure was efficient to document the emergence of transitive relations (B-C). According to the literature, the study suggest that non humans seem more ready to present the emergence of transitive than symmetric relations. Future studies shall engage in training C-A relations and retesting the emergence of C-B relations
Acesso aberto (Open Access)
Thorndike (1932) e a assimetria entre reforçamento e punição: uma replicação
(Universidade Federal do Pará, 2015-03-06) WANZILER, Jesiane Silva; CARVALHO NETO, Marcus Bentes de; http://lattes.cnpq.br/7613198431695463
In a series of researches, Thorndike concluded that punishment does not produce direct effects as reward on behavior because some responses of participants continued to be repeated when followed by announcement of “Wrong” (punishment) and the ones followed by “Right” (reward) were all repeated. His results are widely cited to justify the asymmetric interpretation between the effects of the behavioral processes. The present work systematically replicated a study of Thorndike, through three interlinked experiments (20 university in each), in order to discuss the magnitude of the effects of punishment and to contribute to the debate on symmetry and asymmetry between this operation and the reinforcement. A vocabulary list (from a factorial arrangement of 200 or 50 questions and of five or three response alternatives) was presented six times to the participant and the proportion of responses repetition was analyzed. In Experiment 1, with printed lists, “Right” and “Wrong” were the consequences and this last was more effective (suppression of responding of all participants) on the list with 50 questions and three alternatives, confirming previous studies observing greater effectiveness of punishment as the number of items was reduced. In Experiment 2, with the automated task, there were not consistent results of suppression by “Wrong” and, therefore, revealing the manual task with the greater influence on punishment effectiveness. There were also no systematic results in Experiment 3 and the university repeated more errors even when they generated monetary loss. All experiments replicated results as the original work: repetition of some incorrect responses was not suppressed for the potentially punishing consequences. However, repetition of some correct responses was apparently weakened by the potentially reinforcing consequences. Thus, the effectiveness of the behavioral processes may be more linked to the conditions of test and the symmetry or asymmetry between them to the optical of interpretation.