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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Contextual Control of Stimulus Equivalence with Preschool Children

Green, M. Regina 01 May 1986 (has links)
This research asked whether a contextual stimulus in a visual conditional discrimination task controlled membership in classes of stimuli related hierarchically. Six experiments with nonreading preschool children posed the following question: Does a stimulus juxtaposed with a conditional discrimination task control relations among the stimuli involved in the task? In Experiments I and II, printed instance or concept words were juxtaposed with conditional discrimination tasks involving symbols. Results for eight of nine children demonstrated neither conditional nor equivalence relations between words and symbols. Would conditional discrimination training establish classes of visual stimuli composed of selectively nonequivalent subsets? In Experiment III, subjects from the first two experiments were taught conditional relations, then tested for stimulus class development. Printed words that could have been related transitively were not, apparently due to interference by identical letters in certain words, so no stimulus classes developed. Would the equivalence relations sought in Experiment III develop without a history where printed words were unnecessary to conditional discrimination tasks? For Experiment IV-A, one experimentally naive child was taught the same conditional relations as Experiment III subjects. Two stimulus classes emerged, each containing two subsets that were selectively nonequivalent depending upon trial context. Are direct or transitive stimulus relations more likely to control responding? In experiment IV-B, the subject from Experiment IV-A expressed more direct than transitive relations on modified matching trials. Would interference by identical elements in words be precluded by training conditional relations among words directly? One child in Experiment V was taught conditional relations between concept words and instance words, and instance words and symbols. Results suggested that stimulus class development, which would have answered the question affirmatively, had begun but was incomplete. Would providing auditory labels for some printed words preclude interference by identical elements, allowing nonidentical words to be related transitively? In Experiment VI, one child was taught auditory labels for selected printed words, followed by the same visual conditional discrimination training provided in Experiment III. Two stimulus classes developed, requiring transitive and symmetric relations among printed words.
2

"Önskar man hade två käftar och tre telefoner" : COCOM och kontroll inom flygledning / "Wish I had two mouths and three phones" : COCOM and Control in Air Traffic Control

Rankin, Erik January 2015 (has links)
Denna magisteruppsats redogör för en anpassning av COCOM (Contextual Control Model) till flygledningsdomänen. COCOM är en modell som kan användas för att beskriva och förutse kontroll hos operatörer i komplexa system. En central del av modellen är begreppet kontrollnivå vilket beskriver hur graden av kontroll hos ett JCS (Joint Cognitive System) beror av och påverkar de parametrar som beskriver dess prestation. Fokus i denna uppsats ligger på det JCS som omfattar flygledaren i sin arbetsposition. I uppsatsen anpassas Hollnagels generella beskrivning av kontrollnivåer i COCOM till flygledningsdomänen. Till grund för anpassningen ligger en kvalitativ studie i form av observation och intervju av sju operativa flygledare vid en svensk kontrollcentral. De tre parametrarna målavvägning, subjektivt tillgänglig tid samt planering och prioritering befinns särskilt lämpliga för att beskriva kontroll inom flygledning. I uppsatsen identifieras också, med utgångspunkt i resilience engineering, tolv strategier som flygledare använder för att bibehålla kontroll i det vardagliga arbetet. Två exempel på strategier är att anpassa sig till kollegor och deras arbetssituation, samt användandet av ”extra ögon”, att låta en kollega övervaka arbetet. Valet av strategi kopplas i uppsatsen samman med vilken kontrollnivå flygledaren befinner sig på. Domänanpassningen av COCOM visar att modellen är lämplig för modellering av operatörer. COCOM för flygledning kan användas för att bättre klassificera prestation specifikt inom detta område, samt som stöd i samband med utvecklandet av nya verktyg och arbetsmetoder. Kunskap om kontrollstrategier kan med fördel utnyttjas vid utbildning av flygledare, som med denna typ av metakunskap kan få mer medvetna verktyg för att bibehålla kontroll.
3

Design of cognitive work support systems for airline operations

Feigh, Karen M. 20 August 2008 (has links)
The thesis begins by examining the evolution of human performance modeling from the initial stimulus-response methods introduced during the industrial revolution to model factory worker productivity, continues with a discussion of the information processing model where human cognition was modeled as a series of actions carried out in a predefined order, and ends with the concept of cognitive control whereby cognition is not considered a context-free mental process but modeled as an individual's ability to maintain control under varying contexts and to counter the effects of disturbances. The results from a preliminary evaluation conducted to determine if CCMs could be measured and if they provided any additional insight cognitive work are presented, and reveal that CCMs could be measured and the self-assessed CCM varied as predicted. A design process is developed which utilizes the CCMs as representing specific patterns of activity, thus specifying the design requirements. Following this design process, a prototype is created and evaluated using a controlled experiment to examine the effectiveness of the CWSS. The experiment examines performance, workload, and patterns of activity, and has several interesting findings. The first is that performance was independent of the almost all of the predictors and covariates including participant's Self-assessed CCM, with the exception of CCM transitions. As in the preliminary study, participants who reported transitioning between CCMs also reported decreased performance, increased frustration and actually performed worse. Second, perceived performance varied linearly with a participant's self-assessed CCM, but not with the actual performance. Third, participants report lower levels of effort when using a CWSS DM that matched their operational CCM. Finally, the design process successfully created a CWSS with DMs which support strategic and tactical CCMs. Unfortunately, no specific performance improvements were found for cases where the participant's CCM matched the DM as hypothesized, calling into question the effectiveness of creating different design modes for performance improvement. This thesis presents two methods for measuring CCMs: one direct single scale and one indirect composite scale. The measurements correlate highly. Both have a high degree of face validity and user acceptance. In the end, the composite measure may be a more robust measure of CCM because it provides a greater degree of diagnosticity by specifically inquiring after different aspects of CCM and is less susceptible to an individual's interpretation of the relative importance of the multiple dimensions of CCMs included in the definitions.
4

Efeitos de variáveis de procedimentos de treino para o estabelecimento do controle contextual de relações condicionais e de equivalência

Castro, Tatiane Carvalho 13 March 2013 (has links)
Made available in DSpace on 2016-06-02T20:30:07Z (GMT). No. of bitstreams: 1 5064.pdf: 2133437 bytes, checksum: 91011d8e6a06f6e7760589cf0b30918d (MD5) Previous issue date: 2013-03-13 / Universidade Federal de Minas Gerais / Studies about the effects of contextual control over equivalence classes have been conducted since the 1980s and a relevant question in this area, both in terms of experimental and applied research, is whether changes in contextual variables could result in changes in classes originally formed under different contextual variables. This research investigated, in four studies, the effects of procedures for establishing the contextual control of conditional relations and equivalence classes. The participants were undergraduate students. The stimuli used as sample and comparison were abstract figures and the contextual stimuli were represented by the colors of the background on which the stimuli were presented. In Study 1, we conducted a procedure for the formation of equivalence classes on backgrounds of red and blue colors. Later we conducted a test that showed the equivalence relations in the presence of contextual stimuli blue, red and green. The results showed that participants had responses consistent with the last equivalence class trained, independent of contextual stimulus. Study 2 replicated the previous study, but tests also showed baseline relations. The results obtained were similar to Study 1. Study 3, initially, partially replicated the procedure of previous studies, only for conditional relations AB and then tested the effects of a conditional discrimination training procedure interspersing the colors of the background. The results revealed that this procedure was most effective in setting the control contextual than those conducted in Studies 1 and 2. Study 4 investigated the effects of a interpersed training procedure for the establishment of the contextual control of recombined conditional relations. The procedure consisted of six phases. Phase1 was conducted a conditional discrimination training interspersing the colors of the background. In Phase 2, we carried out the test of relations trained in Phase1. In Phase 3, tests were conducted in which trials were included with a green background. Phase 4 included the symetry relations. Phase 5 presented the same relations were tested in Step 4, however the configuration of stimulus presentation on the computer screen was different. Finally, in Step 6, a test aimed to verify the abstraction of responding under contextual control, with new stimulus and background colors. The results suggest that the contextual control was established for some of the participants. Investigations about the baseline relations training, specifically the interspersed training , for establishing the contextual control is required to produce more robust results. / Estudos acerca dos efeitos do controle contextual sobre classes de equivalência vêm sendo conduzidos desde a década de 1980 e uma questão relevante nesta área, tanto do ponto de vista experimental quanto aplicado, é se mudanças em variáveis contextuais poderiam resultar em mudanças em classes originalmente formadas sob variáveis contextuais diferentes. A presente pesquisa investigou, em quatro estudos, os efeitos de variáveis de procedimentos para o estabelecimento do controle contextual de relações condicionais e classes de equivalência. Os participantes dos estudos foram estudantes universitários. Os estímulos utilizados como modelo e comparação foram figuras abstratas e os estímulos contextuais foram representados pelas cores do plano de fundo sobre os quais os estímulos eram apresentados. No Estudo 1, foi conduzido um procedimento para a formação de classes de equivalência diferentes na presença das cores azul e vermelha e posteriormente foi conduzido um teste que apresentava as relações de equivalência na presença dos estímulos contextuais azul, vermelho e verde. Os resultados revelaram que os participantes apresentaram respostas consistentes com a última classe de equivalência treinada, independente do estímulo contextual. O Estudo 2 replicou o estudo anterior, incluindo nos testes, além de relações de equivalência, relações de linha de base. Os resultados obtidos foram semelhantes ao do Estudo 1. O Estudo 3, inicialmente, replicou parcialmente o procedimento dos estudos anteriores apenas para relações condicionais AB e, em seguida, testou-se os efeitos de um procedimento de treino de discriminação condicional AB intercalando-se as cores do plano de fundo. Os resultados revelaram que este procedimento foi mais eficaz no estabelecimento do controle contextual que os conduzidos nos Estudos 1 e 2. O Estudo 4 avaliou os efeitos de um procedimento de treino intercalado para o estabelecimento do controle contextual de relações condicionais recombinadas. O procedimento contou com seis etapas, sendo que na Etapa 1 foi conduzido um treino de discriminação condicional intercalando-se as cores do plano de fundo. Na Etapa 2, realizou-se o teste das relações treinadas na Etapa1. Na Etapa 3, foram conduzidos testes nos quais foram incluídas tentativas com um plano de fundo da cor verde. A Etapa 4 incluiu as relações de simetria BA. Na Etapa 5, foram testadas as mesmas relações da Etapa 4, no entanto a configuração de apresentação dos estímulos na tela do computador foi diferente. Finalmente, na Etapa 6, conduziu-se um teste cujo objetivo foi verificar a abstração do responder sob controle contextual, com estímulos e cores do plano de fundo inéditas no experimento. Os resultados sugerem que o controle contextual foi estabelecido para parte dos participantes. Investigações acerca dos treinos das relações de linha de base, especificamente do treino intercalado, para o estabelecimento do controle contextual são necessárias para a produção de resultados mais robustos.
5

Controle contextual com o procedimento go/no-go com estímulos compostos / Contextual control with the go/no-go procedure with compound stimuli

Modenesi, Rafael Diego 19 April 2013 (has links)
O Controle Contextual é descrito a partir de (a) uma contingência de cinco termos (Sx-Sc-Sd- R-Sr) em que o estímulo contextual (Sx) exerce controle condicional sobre as discriminações condicionais e (b) permite que um estímulo participe de mais de uma classe de equivalência sem que haja a fusão das classes. O matching-to-sample é o procedimento mais utilizado para investigar o controle contextual. O objetivo deste estudo foi avaliar se o procedimento go/nogo com estímulos compostos, no qual não é possível identificar as funções condicional e discriminativa, produziria classes de equivalência que compartilham estímulos. Se estas classes fossem produzidas, apenas uma parte da definição de controle contextual (b) seria atestada. Seis universitários realizaram uma tarefa nas fases de treino na qual respostas aos compostos A1C1, A2C2, B1D1, B2D2, X1Y1, X2Y2, X1A1B1, X1A2B2, X2A1B2, X2A2B1 eram seguidas, intermitentemente, por 10 pontos e respostas aos compostos A1C2, A2C1, B1D2, B2D1, X1Y2, X2Y1, X1A1B2, X1A2B1, X2A1B1, X2A2B2 não eram seguidas de consequências. Os estímulos eram formas abstratas. Para se atestar o estabelecimento do controle contextual, os participantes deveriam responder aos compostos Y1C1D1, Y1C2D2, Y2C1D2, Y2C2D1 e não deveriam responder aos compostos Y1C1D2, Y1C2D1, Y2C1D1, Y2C2D2. Este padrão de respostas indicaria a formação de quatro classes de equivalência que compartilham estímulos: X1A1B1Y1C1D1, X1A2B2Y1C2D2, X2A1B2Y2C1D2, X2A2B1Y2C2D1. Quatro dos seis participantes apresentaram desempenhos indicando que é possível estabelecer o controle contextual a partir do procedimento go/no-go com estímulos compostos, sem especificar diferentes funções (e.g., discriminativa, condicional e contextual) para os estímulos envolvidos nestas discriminações. Em função desses resultados, parte (a) da definição de controle contextual mais recorrentemente empregada pode ser questionada / Contextual control is described from (a) a five-term contingency in which the contextual stimulus (Sx) exerts conditional control over conditional discriminations (Sctx Sc Sd R Sr) and (b) allows one stimulus to participate in more than one equivalence class, without merging them into one. Matching-to-sample is the mostly employed procedure to investigate the contextual control. The presented study aimed to evaluate whether a go/no-go procedure that present stimuli in the same manner, without specifying any different stimuli functions, would produce equivalence classes that share stimuli. If equivalence classes could be established with this procedure, only one part of contextual control definition (b) would be met. Six undergraduate were submitted to a task in Training Phase in which responses to A1C1, A2C2, B1D1, B2D2, X1Y1, X2Y2, X1A1B1, X1A2B2, X2A1B2, X2A2B1 compound stimuli were intermittently followed by 10 points, and responses to A1C2, A2C1, B1D2, B2D1, X1Y2, X2Y1, X1A1B2, X1A2B1, X2A1B1, X2A2B2 were not. Two or three abstract forms composed compound stimuli. In Phase III, to certify the establishment of contextual control participants should respond to Y1C1D1, Y1C2D2, Y2C1D2, Y2C2D1 compounds and did not respond to Y1C1D2, Y1C2D1, Y2C1D1, Y2C2D2 compounds. This pattern of responses also indicates the formation of four equivalence classes: X1A1B1Y1C1D1, X1A2B2Y1C2D2, X2A1B2Y2C1D2, X2A2B1Y2C2D1. Four of six participants showed the establishment of contextual control using a go/no-go procedure that do not specify any specific functions for the stimuli. These results indicate that part (a) of the contextual control definition currently used can be questioned
6

The effect of target fascination on control and situation awareness in a multiple remote tower center : A human factors study

Sjölin, Victor January 2015 (has links)
The Multiple Remote Tower Center concept (mRTC) is a cutting edge project which allows one air traffic control officer (ATCO) to be in charge of multiple remotely situated airports simultaneously. When implemented, it will revolutionise how air traffic is managed at smaller airports and allow for increased efficiency and decreased operational costs. Consequently, at the time of writing a lot of effort is going into evaluating this new way of air traffic management from a safety perspective. Air traffic management has been defined as an issue maintaining situational awareness and exercising control. This thesis aims to investigate how the phenomenon target fascination affects the ATCOs ability to exercise control over its controlled airspace and maintain its situation awareness. It does so by creating a baseline scenario of work in a mRTC, and then comparing the ATCOs performance in the baseline scenario with its performance in the same corresponding scenario, but with elements of target fascination introduced. The differences in the scenarios are analysed using the Contextual Control Model, the Extended Control Model and a holistic framework for studying situation awareness. The analysis shows that target fascination does affect the ATCOs ability to maintain control, but not radically so, and only for a short period of time. The target fascination forces the ATCO to rely on information in the immediate environment to a higher degree than during regular work, as opposed to making decisions based on a holistic understanding of the situation and high level goals. However, once the understanding of the situation have been re-established, the level of control quickly returns to normal levels. Situation awareness is thus a key concept in maintaining control. The situation awareness analysis show that target fascination affects situation awareness by causing the ATCOs understanding of the situation to become outdated without the ATCOs knowledge. Because of this, there may be developments in the situation that the ATCO is not aware of, which hinders it from acting as it normally would. In some cases an intervention from an external actor or element may be necessary to break the fascination and re-establish the ATCOs understanding for the situation. As soon as the fascination is broken, the ATCO quickly takes steps to re-establish its situation awareness and return to normal operations.
7

Controle contextual com o procedimento go/no-go com estímulos compostos / Contextual control with the go/no-go procedure with compound stimuli

Rafael Diego Modenesi 19 April 2013 (has links)
O Controle Contextual é descrito a partir de (a) uma contingência de cinco termos (Sx-Sc-Sd- R-Sr) em que o estímulo contextual (Sx) exerce controle condicional sobre as discriminações condicionais e (b) permite que um estímulo participe de mais de uma classe de equivalência sem que haja a fusão das classes. O matching-to-sample é o procedimento mais utilizado para investigar o controle contextual. O objetivo deste estudo foi avaliar se o procedimento go/nogo com estímulos compostos, no qual não é possível identificar as funções condicional e discriminativa, produziria classes de equivalência que compartilham estímulos. Se estas classes fossem produzidas, apenas uma parte da definição de controle contextual (b) seria atestada. Seis universitários realizaram uma tarefa nas fases de treino na qual respostas aos compostos A1C1, A2C2, B1D1, B2D2, X1Y1, X2Y2, X1A1B1, X1A2B2, X2A1B2, X2A2B1 eram seguidas, intermitentemente, por 10 pontos e respostas aos compostos A1C2, A2C1, B1D2, B2D1, X1Y2, X2Y1, X1A1B2, X1A2B1, X2A1B1, X2A2B2 não eram seguidas de consequências. Os estímulos eram formas abstratas. Para se atestar o estabelecimento do controle contextual, os participantes deveriam responder aos compostos Y1C1D1, Y1C2D2, Y2C1D2, Y2C2D1 e não deveriam responder aos compostos Y1C1D2, Y1C2D1, Y2C1D1, Y2C2D2. Este padrão de respostas indicaria a formação de quatro classes de equivalência que compartilham estímulos: X1A1B1Y1C1D1, X1A2B2Y1C2D2, X2A1B2Y2C1D2, X2A2B1Y2C2D1. Quatro dos seis participantes apresentaram desempenhos indicando que é possível estabelecer o controle contextual a partir do procedimento go/no-go com estímulos compostos, sem especificar diferentes funções (e.g., discriminativa, condicional e contextual) para os estímulos envolvidos nestas discriminações. Em função desses resultados, parte (a) da definição de controle contextual mais recorrentemente empregada pode ser questionada / Contextual control is described from (a) a five-term contingency in which the contextual stimulus (Sx) exerts conditional control over conditional discriminations (Sctx Sc Sd R Sr) and (b) allows one stimulus to participate in more than one equivalence class, without merging them into one. Matching-to-sample is the mostly employed procedure to investigate the contextual control. The presented study aimed to evaluate whether a go/no-go procedure that present stimuli in the same manner, without specifying any different stimuli functions, would produce equivalence classes that share stimuli. If equivalence classes could be established with this procedure, only one part of contextual control definition (b) would be met. Six undergraduate were submitted to a task in Training Phase in which responses to A1C1, A2C2, B1D1, B2D2, X1Y1, X2Y2, X1A1B1, X1A2B2, X2A1B2, X2A2B1 compound stimuli were intermittently followed by 10 points, and responses to A1C2, A2C1, B1D2, B2D1, X1Y2, X2Y1, X1A1B2, X1A2B1, X2A1B1, X2A2B2 were not. Two or three abstract forms composed compound stimuli. In Phase III, to certify the establishment of contextual control participants should respond to Y1C1D1, Y1C2D2, Y2C1D2, Y2C2D1 compounds and did not respond to Y1C1D2, Y1C2D1, Y2C1D1, Y2C2D2 compounds. This pattern of responses also indicates the formation of four equivalence classes: X1A1B1Y1C1D1, X1A2B2Y1C2D2, X2A1B2Y2C1D2, X2A2B1Y2C2D1. Four of six participants showed the establishment of contextual control using a go/no-go procedure that do not specify any specific functions for the stimuli. These results indicate that part (a) of the contextual control definition currently used can be questioned
8

Strokekedjan från början till slut : En etnografisk studie om farlighet och tid i en akut vårdkedja / An ethnographic study of decisionmaking during handling of acute stroke patients

Ståhl, Sally January 2012 (has links)
Varje år drabbas 30 000 svenskar av stroke, vilket innebär stora personliga omställningar och stora kostnader för samhället. Den mest effektiva behandlingen, trombolys, måste ges så snart som möjligt för att ha god effekt.  Samtidigt som det är av största vikt att ta reda på om patienten har några differentialdiagnoser som gör behandlingen riskfylld. Den här studien undersöker hur strokekedjan går till och vilka faktorer som påverkar beslutsfattandet. Studien är baserad på etnografiska fältstudier på fyra svenska sjukhus och materialet är analyserat med metoder från sammansatta kognitiva system och målorienterad design. Resultaten visar att trots olika organiserade strokekedjor på de olika sjukhusen är processerna desamma och direkt kommunikation är mest framgångsrik för att effektivt sprida information mellan dem. Neurologjouren är viktig roll som, liksom resten av aktörerna i strokekedjan, ständigt balanserar sitt beslutsfattande mellan effektivitet och grundlighet. Kombinationen av analyser ger resultat både på system- och individnivå. Möjligheter för förbättrade strokekedjor ges i termer av logistiska, tekniska och organisatoriska förslag. / 30 000 people in Sweden get a stroke every year. This leads to large personal adaptions as well as high costs for the society. The most efficient treatment, thrombolysis, must be given as soon as possible to have a good effect. At the same time it is very important to find out if the patient has any differential diagnosis that can make the treatment hazardous. This study investigates how the course ov events around acute stroke patients take place and important factors for the decision making. The studiy is based on ethnographic field studys on four swedish hospitals. The material is analysed with methods from joint cognitive systems and goal-oriented design. The results show that in spite of different organisation of the course  of events around acute stroke patients are the processes and direct communication most successful for effective spread of information between the processes. The neurologist on call is an important roll who, as well as the rest of the participants in the course of events, balances the decision making between efficiency and thoroughness. The combination of analysis gives results on both system- and individual levels. Possibilites for improvents are given in three categories: logistic, technological and organizational.

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