• Journal of Digital Contents Society
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• v.18 no.7
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• pp.1249-1257
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• 2017

Due to the 4th industrial revolution and an aged society, many studies are being conducted to apply virtual reality to medical field. Research on dementia is especially active. This paper proposes virtual reality based on cognitive rehabilitation contents using image recognition and clustering method to improve cognitive and physical disabilities caused by dementia. Unlike the existing cognitive rehabilitation system, this paper uses travel photos that reflect the memories of the subjects to be treated. In order to generate automated cognitive rehabilitation contents, we extract face information, food pictures, place information, and time information from photographs, and normalization is performed for clustering. And we present scenarios that can be used as cognitive rehabilitation contents using travel photos in virtual reality space.

• Korean Journal of Cognitive Science
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• v.16 no.2
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• pp.69-92
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• 2005

A brief survey of linguistic studies on the nature of contrastive information in discourse was Presented first, and an attempt was also made to incorporate the Linguistic theories and concepts about contrast in discourse into a psychological framework. A tentative model of processing of contrastive information in discourse was Proposed, and eight experimental studies on the effects of contrastive information on comprehension and memory of short and ions discourses were reviewed. Experimental results showed that contrastive sentences took more time to process at encoding, and yet were recognized faster and cued-recalled in greater amount than noncontrastive sentences. It was also found that levels of contrast in the discourse structure have some effects on encoding time. It was further found that the sentence immediately following the contrastive sentence was processed slowly regardless of whether it does or does not resolve the contrast. The implications of the results of empirical studies were discussed in relation to developing a research framework that integrate coherence studies and contrast studies urns the two disciplines of linguistics and cognitive psychology.

• Proceedings of the Korean Society for Cognitive Science Conference
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• 2000.05a
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• pp.55-60
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• 2000

연속재인과제에서 자극을 즉각적으로 반복 제시하거나 지연 반복 제시할 경우 사건관련전위에 차이가 나타나는지, 만약 차이가 관찰되면 자극 제시 후 어느 시점에서 차이가 두드러지게 나타나는지를 조사하였다. 실험 결과 즉각적 재인이 지연 재인에 비해 더 높은 반응정확율과 더 빠른 반응시간을 보였고 사건관련전위에서는 P300의 진폭이 더 컸고 잠재시간도 더 빨랐다. 그리고 지연재인에서 관찰되는 N400이 즉각적 재인에서는 나타나지 않았다. 지연재인에 비해 즉각적 재인에서 P300의 진폭이 더 크고 잠재시간이 더 빠르게 나타난 것은 P300이 template matching을 통한 정보처리 과정을 반영해 준다는 주장을 지지해 준다. 즉 즉각적 재인에서는 지연 재인에 비해 template matching이 훨씬 더 정확하고 빨리 일어나며 이 결과 P300의 진폭이 커지고 잠재시간이 더 빨라진 것으로 이해된다. 즉각적 재인에서는 방금 제시된 자극(시간 간격은 2초)을 재인하기 때문에 기억의 탐색 과정이 요구되지 않는 반면 5개의 간섭 단어 후에 반복 제시되는 단어를 재인하는 지연 재인에서는 단어에 대한 탐색 과정이 필요하며, 이에 따라 N400이 초래된 것으로 여겨진다. 이 결과는 N400이 기억 탐색 과정을 반영한다는 주장을 지지해 준다. 사건관련 전위에서 즉각적 재인과 지연 재인의 차이는 자극 제시 300ms에서 450ms사이에 가장 두드러지게 나타났다.

• 한국사회복지학회:학술대회논문집
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• 2007.04a
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• pp.431-438
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• 2007

• Science of Emotion and Sensibility
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• v.17 no.2
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• pp.63-76
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• 2014

Although most behavioral reaction times (RTs) for cognitive tasks exhibit positively skewed distributions, the majority of studies primarily rely on a measure of central tendency (e.g. mean) which can cause misinterpretations of data's underlying property. The purpose of current study is to introduce procedures for describing characteristics of RT distributions, thereby effectively examine the influence of experimental manipulations. On the basis of assumption that RT distribution can be represented as a convolution of Gaussian and exponential variables, we fitted the ex-Gaussian function under a maximum-likelihood method. The ex-Gaussian function provides quantitative parameters of distributional properties and the probability density functions. Here we exemplified distributional analysis by using empirical RT data from two conventional visual search tasks, and attempted theoretical interpretation for setsize effect leading proportional mean RT delays. We believe that distributional RT analysis with a mathematical function beyond the central tendency estimates could provide insights into various theoretical and individual difference studies.

• Journal of the Korean Institute of Intelligent Systems
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• v.27 no.1
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• pp.1-6
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• 2017

Recent researches on radio frequency energy harvesting networks(RF-EHNs) with limited energy resource like battery have been focusing on the development of a new scheme that can effectively extend the whole lifetime of a network to semipermanent. In order for considerable increase both in the amount of energy obtained from radio frequency energy harvesting and its charging effectiveness, it is very important to design a network that supports energy harvesting and data transfer simultaneously with the full consideration of various characteristics affecting the performance of a RF-EHN. In this paper, we proposes an interference-based charging aware routing protocol(ICARP) that utilizes interference information and charging time to maximize the amount of energy harvesting and to minimize the end-to-end delay from a source to the given destination node. To accomplish the research objectives, this paper gives a design of ICARP adopting new network metrics such as interference information and charging time to minimize end-to-end delay in energy harvesting wireless networks. The proposed method enables a RF-EHN to reduce the number of packet losses and retransmissions significantly for better energy consumption. Finally, simulation results show that the network performance in the aspects of packet transmission rate and end-to-end delay has enhanced with the comparison of existing routing protocols.

• Korean Journal of Cognitive Science
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• v.16 no.4
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• pp.271-285
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• 2005

An experiment was conducted to investigate the effect of three types of prior knowledge (domain related knowledge, summary-writing strategy knowledge, and neutral unrelated knowledge) and two types (analytic and wholistic) of cognitive styles on the quality of the summary writing of a descriptive text. The results showed that learning domain-related knowledge and summary-writing-strategy knowledge increased the level of understanding of the target text and the quality of the summary; the former operating mainly at the understanding phase, and the latter operating mainly during the summary planning and producing phases. The effect of the types of cognitive style was found somewhat limited but mainly operating In the process of planing the summary. Other features of time course in writing a summary were further discussed.

• Journal of Advanced Navigation Technology
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• v.23 no.4
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• pp.322-327
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• 2019

In this paper, we propose first a scheme of grouping spectrum holes that are created in the multiple channels of primary users, and then by using the scheme we enhance quality of service (QoS) of wideband cognitive radio users in cellular cognitive radio networks. In our scheme, spectrum holes created in each primary channel are predicted by Wiener prediction process, and then the predicted spectrum holes happened in the same time are grouped into a group. The wideband cognitive radio users explore the group of spectrum holes to improve their QoS. Simulation results show that their handoff calls dropping rate and initial calls blocking rate are significantly reduced in our scheme, compared to those in the single primary channel.

• Proceedings of the Korean Society of Computer Information Conference
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• 2009.01a
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• pp.231-236
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• 2009

본 연구에서는 집이나 사무실과 같은 일상 공간에서 발생할 수 있는 연간의 일상생활행위 (ADL: Activities of Daily Living) 들을 인지하는 분산 모델을 제시한다. 사용자의 환경 정보, 위치 정보 및 행위 정보를 간단한 센서들이 부착된 가정용 기기들과 가구, 식기들을 통해 무선 센서 네트워크를 통해 수집하며 분석한다. 하지만 이와 같은 다양한 기기의 활용과 충분히 분석되어지지 않은 데이터들은 본 논문에서 제시하는 일상 환경에서 고차원의 ADL 모델을 구축하기 어렵게 한다. 그러나 ADL들이 생성하는 센서 데이터들과 센서 데이터들의 순서들은 어떤 행위가, 이루어지고 있는지 인지할 수 있도록 도와준다. 따라서 이 센서 데이터들의 순서를 특정 행위 패턴을 분석하는 데 활용하고, 이를 통해 분산 선형 시간 추론 알고리즘을 제안한다. 이 알고리즘은 센서 네트워크와 같은 소규모 시스템에서 행위를 인지하는 데 적절하다.

• 한국정보교육학회:학술대회논문집
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• 2008.01a
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• pp.154-159
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• 2008

2005년 사이버가정학습 시스템이 구축되어 운영되고 있지만 많은 학생이 이를 외면하고 사교육에 많은 시간과 비용을 사용하고 있다. 사이버가정학습을 이용하는 학생들의 인지양식 특성을 두 집단으로 나누어 각각 교육만족도를 분석하였다. 그 결과 장독립적인 인지양식 학생들은 학원, 과외 등의 사교육으로 사이버가정학습 이용률이 저조하였고 잘 정리된 자료와 콘텐츠를 사이버가정학습에서 이용하고 싶어 했고 사이버가정학습의 내용과 콘텐츠에 대해서는 긍정적인 의견이 많았다. 장의존적인 인지양식 학생들은 가정에서 컴퓨터 사용 환경이 쉽지 않아 이용하지 못하는 학생이 많았으며 현재 사이버가정학습의 만족도가 높게 나타났으나 만족도 조사에서 사이버선생님에 대한 불만이 비교적 많이 나타났다.