• 품질경영학회지
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• 제23권3호
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• pp.69-83
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• 1995

In a large number of literature on of inspection tasks, one of the most consistent findings is the existence of large and consistent differences among inspectors. It is possible that the individual difference is described by the difference of cognitive skills, because cognitive skills are required more than manual skills in inspection tasks. Therefore, a set of cognitive factors in human information processing may underly human performance in inspection tasks. In this study, a cognitive skill was described as the relative importance of the cognitive factors involved. A hierarchical task analysis and a fuzzy hierarchical analysis were used to represent how the importance of cognitive factors contribute to inspection performance. An experiment was conducted using the computer simulations of PCB inspection tasks. The results revealed that the subject group with better performance showed the importance weights of cognitive factors in the following rank; (attention, perception, judgement, classification, recognition)<(detection)$\ll$(memory). The results of the experiment can serve as a selection criterion for efficient inspection performance and the information of skilled learning for an inspection training program. The usefullness of a hierarchical task analysis and a fuzzy hierarchical task analysis for the analysis of cognitive tasks are also confirmed.

• 한국통신학회논문지
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• 제32권8A호
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• pp.836-846
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• 2007

유비쿼터스 사회가 도래함에 따라 모든 사회가 무선통신과 밀접한 연관성을 가지게 되었다. 하지만 늘어나는 주파수 수요는 주파수 자원의 고갈을 야기하였다. 이와 같이 주파 주파수 자원의 중요성이 부각되어 주파수 공유 기술이 필요하게 되었다. 제안한 Cognitive UWB 시스템은 넓은 주파수 대역을 사용하는 UWB(Ultra Wideband) 기술과 채널 환경을 인지하여 사용하지 않는 비어있는 주파수 대역을 이용하는 CR(Cognitive Radio) 기술이 합해진 기술이다. 본 논문에서는 Cognitive UWB 시스템의 세부 기술을 설명하고 시뮬레이션을 통하여 원하는 마스크를 충족시키고 타 시스템의 간섭을 회피하여 성능향상을 보였다.

• 한국감성과학회:학술대회논문집
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• 한국감성과학회 2001년도 춘계학술대회 논문집
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• pp.20-25
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• 2001

In recent years, the concern about a user center design in increasing, and it's needed to task a user's visual cognitive characteristics for information presentation. Then this study aims to grasp user's cognitive characteristics about the information presentation by analyzing the fixation points. In the experiment, actually subject operated a copy machine. Recorded the fixation point movement of the operation panel by the eye mark recorder. Analysis examined the screen interface of the operation panel from the field of a fixation point trace. The top down type fixation oder by experience or the context became clear as a result. Furthermore, the difference of the fixation order by skill level was also examined. In this study, it was assumed that to grasp the visual cognitive characteristics becomes the key of efficient information.

• Asia pacific journal of information systems
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• 제16권1호
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• pp.45-69
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• 2006

Technology Acceptance Model (TAM) has been widely used to predict user's behavior to accept the technology. Prior researches have been mainly focused on innovation constructs such as perceived usefulness and perceived ease of use. However, very little research has been conducted to understand individual mental beliefs in technology acceptance and imitation influence. This study integrates Technology Acceptance Model (TAM), Flow Theory (FT) and Diffusion of Innovation Theory (DIT). This paper indicates that imitation context, cognitive absorption (CA) based Flow theory and innovation context are the three important factors influencing user acceptance of information technologies. The proposed model has been tested among 232 users of MP3 players. Results showed that innovation context and cognitive absorption have positive influences on intention to use technology. Not all factors of the imitation context have direct effect on intention to use. However, we found that imitation context has positive influence on intention to use technology through cognitive absorption.

• Journal of Communications and Networks
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• 제14권6호
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• pp.710-718
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• 2012

The implementation of a common control channel is one of the most challenging issues in cognitive radio networks, since a fully reliable control channel cannot be created without reserving bandwidth specifically for this purpose. In this paper, we investigate a promising solution that exploits the ultra wide band (UWB) technology to let cognitive radio nodes discover each other and exchange control information for establishing a communication link. The contribution of this paper is threefold: (i) We define the communication protocol needed to let cognitive radio nodes discover each other and exchange control information for link set up, (ii) we overcome the gap in coverage, which typically exists between UWB and long-medium range technologies, by using multi-hop communication, (iii) we evaluate the performance of our approach by adopting an accurate channel model and show its benefits with respect to an in-band signaling solution.

• 한국수학교육학회지시리즈A:수학교육
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• 제46권4호
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• pp.483-492
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• 2007

The purpose of this study was to investigate the relation between the cognitive processes and the mathematical achievement of the 4th grade students. And according to the several studies, there were significant relation between cognitive processes and achievement. Based on the PASS(Planning-Attention-Simultaneous-Successive Processes) Model presented by Das and Naglieri, four cognitive process variables were selected. The results of this study as follows. First, there was not significant relation between attention and mathematical achievement. Second, there was significant relation between planning and mathematical achievement. Third, there was significant relation between simultaneous/successive processes and mathematical achievement. Fourth, the students who got higher scores in the two types (simultaneous/successive)of information processing had more mathematical achievement. Specially, the students who got higher scores in the type of simultaneous information processing had higher scores in mathematical achievement. These results indicated that planning and simultaneous information processing had influence on the mathematical achievement.

• Journal of information and communication convergence engineering
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• 제13권4호
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• pp.241-247
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• 2015

Cognitive radio has been attracting increased attention as an effective approach to improving spectrum efficiency. One component of cognitive radio, spectrum sensing, has an important relationship with the performance of cognitive radio. In this paper, after a summary and analysis of the existing spectrum-sensing algorithms, we report that the existing eigenvalue-based semi-blind detection algorithm and blind detection algorithm have not made full use of the eigenvalues of the received signals. Applying multi-antenna systems to cognitive users, we design a variety of spectrum-sensing algorithms based on the joint distribution of the eigenvalues of the received signal. Simulation results validate that the proposed algorithms in this paper are able to detect whether the signal of the primary user exists or not with high probability of detection in an environment with a low signal-to-noise ratio. Compared with traditional algorithms, the new algorithms have the advantages of high detection performance and strong robustness

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제9권1호
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• pp.331-343
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• 2015

We propose a distributed medium access control protocol for cognitive radio networks to opportunistically utilize multiple channels. Under the proposed protocol, cognitive radio nodes forecast and rank channel availability observing primary users' activities on the channels for a period of time by time series analyzing using smoothing models for seasonal data by Winters' method. The proposed approach protects primary users, mitigates channel access delay, and increases network performance. We analyze the optimal time to sense channels to avoid conflict with the primary users. We simulate and compare the proposed protocol with the existing protocol. The results show that the proposed approach utilizes channels more efficiently.

• 한국운동역학회지
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• 제22권4호
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• pp.405-411
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• 2012

The purpose of this study was to determine the effects of landing height information on landing strategy during a drop landing. Ten healthy male subjects(age: $22.1{\pm}1.9year$, height: $178.4{\pm}7.8cm$, mass: $75.3{\pm}9.4kg$) participated in this study. Each participant was asked to jump with both legs off a 40 cm high box on one of the three plates with different thickness (0 cm, 13 cm, 26 cm). In the first condition, subjects were given both cognitive and visual information about the jumping heights. In the second, they were given only cognitive information without visual one, and in the third, no information about the height was provided to subjects. (Only the data collected from the 40 cm height landing were analyzed and reported in the present study.) The results showed that landing strategies during a double-leg drop landing from 40 cm height were not significantly affected by visual and cognitive information blockages. Also, there were no statistically significant differences in landing strategies between the three conditions even though the mean differences attained in this study seemed to warrant further studies investigating the relationship between landing strategies and cognitive information.

• 인지과학
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• 제19권4호
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• pp.419-441
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• 2008

웹과 디지털 라이브러리가 대중화되면서, 사용자들은 이를 정보 조사나 학습 같은 높은 인지부담을 수반하는 작업에 활용하기 시작한다. 그러나 대부분의 검색엔진 및 브라우저는 사용자에게 단순한 질의 기반 검색 및 항해탐색 기능만을 제공하므로 정보를 해석하고 연계하며 통합하는 등의 역할은 사용자에게 전가한다. 본 논문에서는 인간-웹 상호작용을 위한 이단 모델(Two-level M여el)이라고 부르는 개인화된 지식구조를 제안한다. 이 구조는 지식공간과 정보공간으로 구성되어 있으며, 새롭게 지식공간을 구성하고 이를 이용하는 명령(Operation)을 제공한다. 지식 공간은 웹에서 상호작용을 통해 검색된 결과에 대한 개념적인 해석이라고 할 수 있으며, 토픽 및 토픽간의 관계를 통해서 이 지식 공간이 구성된다. 이러한 지식 공간은 정보공간의 정보객체와 연결되어 있어 지식공간으로부터 원하는 정보에 대한 접근이 가능하다. 이 모델에 기반 하여 구현된 시스템을 통해 정보탐색 태스크 중 가장 높은 인지부담을 요구하는 탐험적 검색 환경 아래서의 실험을 수행하여 사용자 인지부담 절감 효과를 확인 할 수 있었으며, 향후 개인의 효과적인 정보 탐색을 위한 가치 있는 메타데이터로서의 활용이 기대된다.