• Composites Research
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• v.17 no.5
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• pp.54-60
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• 2004

A new three-dimensional model for predicting the relationship between the prestrain of the composite and the amount of phase transformation of shape memory alloy inducing shape memory effect has been proposed by using Eshelby's equivalent inclusion method with Mori-Tanaka's mean field theory. The model composite is aluminum matrix reinforced with short TiNi fiber shape memory alloy, where the matrix is work-hardening material of power-law type. The analytical results predicted by the current model show that most of the prestrain is induced by the plastic deformation of the matrix, except the small prestrain region. The strengthening mechanism of the composite by the shape memory effect should be explained by excluding its increase of yield stress due to the work-hardening effect of the matrix.

• Korean Journal of Cognitive Science
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• v.23 no.2
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• pp.225-248
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• 2012

The summed-similarity model of visual short-term recognition proposes that the estimated amount of summed similarity between remembered items and a recognition probe determines recognition judgement decision (Kahan & Sekuler, 2002). This study examined the effect of a task-irrelevant location change on the recognition decision against two remembered Gabor gratings differing in their spatial frequencies. On each trial in Experiment, participants reported if two gratings displayed across the visual fields are the same or not as the probe grating displayed after about a second of memory delay. The probe grating would be the same as or different from the memory items (lure) by 1 or 4 JND units. The location of the probe would also vary randomly across the left and right visual field with respect to the location of the corresponding memory item. The participants were instructed to perform their recognition task exclusively to the spatial frequencies of the memory items and the probe while ignoring the potential location change of the probe. The results showed that false-recognition rates of the lure probe increased as the summed similarity between the memory items and the probe increased. The rates also further increased in the condition where the probe location was different from the location of the corresponding memory item compared to the condition where the probe location was the same. The increased false-recognition rates indicate that information stored into visual short-term memory is represented as a form of well-bound visual features rather than independent features.

• Science of Emotion and Sensibility
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• v.17 no.3
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• pp.107-116
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• 2014

In the current study, it is suggested that when two emotions are presented through cross-modality, such as auditory and visual, incongruence will influence arousal, recognition, and recall of subjects. The first hypothesis is that incongruent cross-modality does not only increase arousal more than the congruent, but it also increases recall and recognition more than congruent. The second hypothesis is that arousal modulates recall and recognition of subjects. To demonstrate the two hypotheses, our experiment's conditions were manipulated to be congruent and incongruent by presenting positive or negative emotions, visually and acoustically. For dependent variables, we measured recall rate and recognition rates. and arousal was measured by PAD (pleasure-arousal-dominance) scales. After eight days, only recognition was measured repeatedly online. As a result, our behavioral experiment showed that there was a significant difference between arousal before watching a movie clip and after (p<.001), but no difference between the congruent condition and incongruent condition. Also, there was no significant difference between recognition performance in the congruent condition and incongruent condition, but there was a main effect of the clips' emotions. Interestingly after analyzing recognition rates separately depending on clips' emotions, there was a significant difference between congruent and incongruent conditions in the only negative clip (p= .044), not in the positive clip. In a detailed result, recognition in the incongruent condition is more than in the congruent condition. Furthermore, in the case of recall performance, there was a significant interaction between the clips' emotions shown in the clips and congruent conditions (p=.039). Through these results, the effect of incongruence with negative emotion was demonstrated, but an incongruent effect by arousal could not be demonstrated. In conclusion, in our study, we tried to determine the impact of one method to convey a story dramatically and have an effect on memory. These effects are influenced by the subjects' perceived emotions (valence and arousal).

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2010.04a
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• pp.343-346
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• 2010

형상기억합금이 삽입된 복합체는 힌지나 추가적 작동기 없이 그 자체로서 지능 구조의 역할을 할 수 있어 많은 분야에서 활발히 연구되고 있다. 본 논문에서는 형상기억합금(Shape Memory Alloy) 선이 삽입된 $\cap$자형 복합재를 제안하고, 형상기억합금과 모재가 정해진 경우의 곡률 변화에 영향을 주는 주요 설계 변수를 복합재의 너비, 두께, 형상기억합금의 편심률을 설계변수로 가정하고 유한요소 해석과 패널 제작 및 실험을 통해 검증한다. 먼저 라고다스(Lagoudas)모델을 형상기억합금의 구성방정식으로 이용한 유한요소해석모델을 구성하여 수치해석을 수행하고, 11 종류의 형상기억합금 선이 삽입된 유리섬유강화복합재(Glass Fiber Reinforced Plastic) 패널을 제작하여 열하중에 따른 곡률변화를 관찰한다. 해석결과와 실험결과의 비교를 통해 해석모델의 타당성을 검증하며, 해석을 통해 각 설계 변수들의 곡률변화에 대한 영향을 파악한다.

• Composites Research
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• v.17 no.4
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• pp.18-24
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• 2004

In this paper, active shape control of composite structures actuated by shape memory alloy (SMA) wires is presented. The thermo-mechanical behaviors of SMA wires were experimentally measured. Hybrid composite structures were established by attaching SMA actuators on the surfaces of graphite/epoxy composite beams using bolt-joint connectors. SMA actuators were activated by phase transformation, which induced by temperature rising over austenite finish temperature. In this paper, electrical resistive heating was applied to the hybrid composite structures to activate the SMA actuators. For (aster and more accurate shape/deflection control of the hybrid composite structure, PID feedback controller was designed from numerical simulations and experimentally applied to the SMA actuators.

• Korean Journal of Cognitive Science
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• v.25 no.4
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• pp.385-416
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• 2014

In this study, memory for emotional words was compared between extraverts and introverts, employing signal detection analysis to distinguish differences in discriminative memory and response bias. Subjects were presented with a study list of emotional words in an encoding session, followed by a recognition session. Effects of task difficulty were examined by varying the nature of the encoding task and the intervals between study and test. For an easy task, with a retention interval of 5 minutes (Study I), introverts exhibited better memory (i.e., higher d') than extraverts, particularly for low-frequency words, and response biases did not differ between these two groups. For a difficult task, with a one-month retention period (Study II), performance was poor overall, and only high-frequency words were remembered; also extraverts adopted a more liberal criterion for 'old' responses (i.e., more hits and more false alarms) for positive emotional-valence words. These results suggest that as task difficulty drives down performance, effects of internal control processes become more apparent, revealing differences in response biases for positive words between extraverts and introverts. These results show that extraversion can distort memory performance for words, depending on their emotional valence.

• Science of Emotion and Sensibility
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• v.13 no.4
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• pp.647-658
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• 2010

The purpose of the present study was to investigate the effects of self-regulated neurofeedback training on elementary school students' recall and recognition performance. For this purpose, the participants were randomly allocated to control condition where no training was provided or training condition where participants were trained in 4 self-regulated neurofeedback training sessions. As the dependent measures, correct free, recall rates and correct recognition rates were analyzed. The results showed that overall scores of recall and recognition were enhanced by the administration of the training itself, and as the training sessions advanced. In particular, the effect of the training seemed to induce more positive effect on the both memory tasks when the task difficulty (manipulated by increasing the number of target words) was increased. These results implied that self-regulated neurofeedback training can induce increased recollection ability for words by enhancing attentional process.

• Korean Journal of Cognitive Science
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• v.11 no.3_4
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• pp.83-93
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• 2000

The effect of immediate and delayed recognition memory on event-related potential (ERP) was studied using a continuous recognition memory task and event-related potential (ERP). Among 240 stimulus words 40 words were not repeated. 100 were immediately repeated and 100 were repeated after 5 intervening words. All words presented only once during the experiment were referred to as new words. Subjects responded faster and more accurately to words repeated immediately than to new words a and to those repeated after intervening words. In terms of ERP results the immediately repeated words were associated with large P300 amplitude, early P300 latency and a absence of N400. while words repeated after a delay were associated with small P300 a amplitude. late P300 latency and the presence of N400. N400 was elicited only to new w words and to those repeated after a delay. The general morphology of the waveform was s similar for three stimulus-presentation conditions until around 3l0ms after the onset of stimulus. These results indicate that immediate and delayed recognition memory could be dissociated into two distinct processes possibly being mediated by different cerebral mechanism, and the dissociation between two types of recognition memory emerges around 3l0ms poststim'ulus. The immediate and delayed recognition memory for words are considered in terms of template matching and memory searching.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.10 no.3
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• pp.567-571
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• 2009

This study was conducted in order to investigate the role of working memory in word recognition. As a preliminary step in tackling this topic, word frequency and working memory load were manipulated in a naming task. The results showed that word frequency is significantly involved with the working memory load. The effects of working memory load were greater in low-frequency word processing than in high-frequency word processing. These results indicat that working memory is involved more in the processing of low-frequency words. The implications for the teaching of children at the early reading acquisition stage are discussed in this paper.

• Annual Conference on Human and Language Technology
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• 1990.11a
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• pp.97-103
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• 1990

읽기시간과 재인기억을 통하여 스크립트에 부합되지 않는 정보가 어떻게 처리되는지 알아보았다. 실험 1에서는 문장을 읽고 문장 재인검사틀 하였다. 스크립트 비부합 문장의 읽기시간은 길고 재인 반응시간은 빨랐다. 실험 2, 3은 스크립트에 부합하지 않는 정보가 기억이 잘되는데, 그 이유가 노력의 결과로 다른 정보와 통합되었기 때문인지 아니면 비부합정보가 두드러졌기 때문인지 알아보려고 설계되었다. 실험 2에서는 명제쌍을 만들어 즉시 재인기억을 하였고, 실험 3에서는 피험자가 비부합정보를 충분하게 처리할 수 있도록 자기 속도(self-paced)로 읽고 명제쌍으로 지연재인검사를 했다. 비스크립트 정보와 전형적인 명제로 된 명제쌍이 전형적인 명제쌍보다 반응시간이 길었다. 이 결과는 스크립트 비부합정보는 자체로는 기억이 잘되나 다른 정보와 통합은 되지 않은 것으로 해석되었다.