• 인터넷정보학회논문지
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• 제12권2호
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• pp.1-8
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• 2011

본 논문에서는 무선인지시스템에서 스펙트럼 센싱을 효율적으로 수행하기 위한 선택적 협력 스펙트럼 검출 기법을 제안한다. 제안된 알고리즘에서는 각 무선인지 사용자가 자신의 유도비(likelihood ratio)를 기반으로 자신의 센싱 신뢰도를 평가하고, 센싱 신뢰도에 따른 타이머를 활용하는 경쟁기반의 센싱 결과 보고 메커니즘을 활용한다. 이를 통해, 제안된 선택적 협력 스펙트럼 기법에서는 가장 높은 센싱 신뢰도를 갖는 무선인지 사용자만이 국부 스펙트럼 센싱값을 융합센터로 전송함으로써, 스펙트럼 센싱의 성능을 일정한 레벨로 유지하고, 협력 스펙트럼 센싱의 단점인 제어 트래픽 및 협력 센싱 시간을 줄이는 이점을 갖는다.

• 한국지능시스템학회논문지
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• 제20권1호
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• pp.123-128
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• 2010

어떤 한 프로젝트를 성공할 가능성을 높이기 위해서는 그 성과에 영향을 줄 수 있는 요소들에 대해 정의할 필요가 있다. 인지도는 관련있는 요소들의 인과관계를 조사함으로써 분석하는데 널리 사용되고 있다. 퍼지인지도는 인관관계의 연결강도를 통해 피드백의 개념을 추가한 인지도의 확장 개념을 가지고 있다. 프로젝트 성과는 입력 자원, 수행가능성, 타인의 관심 정도 등에 의해 영향을 받는다. 본 논문에서는 프로젝트의 성과와 이런 요소들간의 인과관계의 정도를 조사 분석하기 위해 퍼지인지도를 활용하여 기업프로젝트의 성공을 위한 모델을 개발하고자 한다.

• 한국통신학회논문지
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• 제34권9A호
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• pp.697-703
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• 2009

인지무선 통신장치(cognitive radio)는 일반적으로 일차 사용자(primary user)와의 간섭을 피하기 위해 어떠한 일차 사용자도 점유하고 있지 않은 주파수 자원을 활용한다. 그러나 비어있는 주파수 자원을 발견할 수 없을 경우, 인지무선 통신장치는 언더레이(underlay) 형태로 일차 사용자들과 주파수를 공유할 수 있으며, 이 때 스스로의 통신이 일차 사용자들에게 간섭을 미치지 않도록 전송 전력을 조절해야 한다. 본 논문은 셀룰라 네트워크의 상향링크 주파수 자원을 사용하는 언더레이 주파수 공유 방법을 제안한다. 셀룰라 네트워크의 범위 안에 존재하는 한쌍의 인지무선 통신장치들이 단방향 점대점(point-to-point) 통신 링크를 생성할 때 사용할 수 있는 전송 전력의 재한을 계산하고, 계산된 전송 전력을 적용할 수 있는 실용적인 상향 링크 공유 방안을 제시한다. 또한 시뮬레이션을 통해 제안된 상향 링크 공유 방안이 하향 링크 주파수 자원을 공유하는 것에 비해 인지무선 통신장치의 부담(overhead)을 줄일 뿐만 아니라 점대점 통신 링크의 수율(throughput) 성능을 향상시킬 수 있음을 보인다.

• 여성건강간호학회지
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• 제22권3호
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• pp.182-190
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• 2016

Purpose: This study was done to identify effects of cognitive function and cancer coping on quality of life among women with breast cancer treated with antineoplastic agents. Methods: The study was correlational research and participants were 145 women with breast cancer who had received antineoplastic agents. Data were collected from October to November, 2015 via online replies. Cognitive function was measured with the Functional Assessment of Cancer Therapy-Cognitive Function Version-3 (FACT-Cog), cancer coping, with the Korean Cancer Coping Questionnaire (K-CCQ), and quality of life with the Functional Assessment of Cancer Therapy-Breast Version-4 (FACT-B). Data were analyzed using descriptive statistics, t-test, ANOVA, $Scheff{\acute{e}}$ test, ANCOVA, Bonferroni test, partial correlation coefficient, and hierarchical multiple regression with SPSS 21. Results: Cognitive functions, total individual coping, and interpersonal coping explained 42% of quality of life. Cognitive function (${\beta}=.35$, p<.001) was the best predictor of quality of life, followed by total individual coping (${\beta}=.34$, p<.001), and interpersonal coping (${\beta}=.26$, p<.001). Conclusion: Results indicate that cognitive function and cancer coping are meaningful factors for quality of life among breast cancer survivors. Therefore when developing intervention programs for these women, content on cognitive function and coping skills as well as coping resources should be included.

• 한국어교육
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• 제29권2호
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• pp.73-100
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• 2018

The purpose of this study is to investigate learner-learner dialogue during speaking tasks. In the Korean language classroom, conversation between learners is an important activity as speaking practice. However, learner dialogue is also a tool to enable learners to collaboratively conduct various cognitive activities in the classroom. In previous research, it was unfolded that through learner-learner dialogue, learners can solve second-language related problems and set a goal to carry out tasks. Therefore, this study analyzed learner-learner dialogue to investigate what kinds of cognitive activities are activated during the role-play task. As a result, the learners collaboratively generated and monitored language and content for role play. Also, in order to accomplish tasks more successfully, learners shared the same understanding about the goal of the task, and tried to manage the task procedure. Through learner-learner dialogue, learners can participate in cognitive activities such as content, language construction, and task management voluntarily without the help from teachers. This means that learner-learner dialogue can be an activity to support language learning tasks. Also, it can make learners actively involved in learning and by sharing resources with each other. It is also important that learners can experience language use that participates in real-world communication activities, such as learning in the classroom and collaborating with peer learners. This study is an exploratory study for a basic understanding of learner's conversation as a cognitive activity, and the scope of the study is limited to clarifying contents of learner-learner dialogue as a cognitive activity in speaking tasks. Based on the findings of this study, future research should be conducted on the function of learner-learner dialogue as a cognitive activity in Korean language learning and its role in the classroom of Korean language education.

• 대한가정학회지
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• 제33권6호
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• pp.137-148
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• 1995

The purpose of this study was to classify the cognitive management style of housewives, to explore the effect of demographic variables on the style, and to investigate satisfaction of resources such as money, time and energy, according to different styles. For this purpose, the samples of 355 housewives were collected in Seoul. And various analysis methods, such as frequencies, percentages, means, chi-square test and GLM, were employed. The results of this study were as follows ; 1) Among 355 respondents, systematic managers, analyzing managers, holistic managers and feeling managers were 103, 96, 82 and 74 respectively. 2) Depending on information gathering and evaluation, the style was influenced by wives' education, wives' employment status, and family life cycle. 3) By style, satisfaction of resource was differenciated significantly. Between money, time and energy resources, especially, satisfaction of energy resource had significant differences.

• Human Ecology Research
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• 제53권5호
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• pp.519-530
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• 2015

This study examines the effects of coping resources on life satisfaction of middle and older caregivers looking after family members with activities of daily living disabilities. Personal resources and socio-relational resources were included as predictors after controlling for demographic characteristics. We studied 154 middle and 132 older adults drawn from the Korean Longitudinal Study of Ageing (KLoSA). The multiple regression results of this study were as follows. First, subjective health and family satisfaction had significant effects on middle-aged caregivers' life satisfaction. Specifically higher levels of subjective health and better relationships with their family predicted higher levels of life satisfaction. Second, cognitive function, household income, and family satisfaction had significant effects on middle-aged caregivers' life satisfaction. Higher household incomes, higher levels of cognitive function, and better relationships with family predicted higher levels of life satisfaction. For both middle and older adults, the effect size of family satisfaction was the largest out of all coping resources. The results revealed discrepancies regarding the importance of coping resources between middle and older caregivers, implying that developing interventions for middle and older caregivers (in accordance with their need for coping resources) is necessary. The results also indicated that having good relationships with one's family was the most important factor for both middle aged and older caregivers' life satisfaction. The results suggest that policies or services focused on endorsing healthy family relationships should be developed to improve the life satisfaction of caregivers.

• 한국인터넷방송통신학회논문지
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• 제9권3호
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• pp.179-185
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• 2009

인지 라디오(CR : Cognitive Radio)는 주파수 자원을 효율적으로 사용하기 위해 제안된 기술로 최근 주파수 자원의 부족 현상을 완화하기 위한 방법으로 연구 되고 있다. 인지 라디오는 주파수 정책에 따라 주파수를 할당받은 우선순위 사용자(Primary user)가 해당 주파수를 사용하고 있지 않을 때 부 사용자(Secondary user)가 빈 주파수를 검출하여 해당 주파수를 사용하는 기술이다. 부 사용자가 우선순위 사용자를 검출하는 기술인 스펙트럼 센싱은 수행하는 과정에서 다중경로 페이딩문제로 인해 성능이 낮아지는데 이를 보완하기 위해 본 논문에서는 다이버시티기법을 사용한다. 다이버시티 기술에는 시간 다이버시티, 주파수 다이버시티, 공간 다이버시티 등이 있는데 본 논문에서는 공간 다이버시티의 한 종류인 안테나 다이버시티를 적용하여 다중경로 페이딩 문제를 해소하며 스펙트럼 센싱의 성능 및 신회성이 높아짐을 모의실험의 결과를 통하여 제시한다.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제8권1호
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• pp.91-107
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• 2014

Device-to-device (D2D) communication is an excellent technology to improve the system capacity by sharing the spectrum resources of cellular networks. Multicast service is considered as an effective transmission mode for the future mobile social contact services. Therefore, multicast based on D2D technology can exactly improve the spectrum resource efficiency. How to apply D2D technology to support multicast service is a new issue. In this paper, a resource allocation scheme based on cognitive radio (CR) for D2D underlay multicast communication (CR-DUM) is proposed to improve system performance. In the cognitive cellular system, the D2D users as secondary users employing multicast service form a group and reuse the cellular resources to accomplish a multicast transmission. The proposed scheme includes two steps. First, a channel allocation rule aiming to reduce the interference from cellular networks to receivers in D2D multicast group is proposed. Next, to maximize the total system throughput under the condition of interference and noise impairment, we formulate an optimal transmission power allocation jointly for the cellular and D2D multicast communications. Based on the channel allocation, optimal power solution is in a closed form and achieved by searching from a finite set and the interference between cellular and D2D multicast communication is coordinated. The simulation results show that the proposed method can not only ensure the quality of services (QoS), but also improve the system throughput.

• 한국항행학회논문지
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• 제20권5호
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• pp.440-445
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• 2016

인지라디오망에서 제한된 스펙트럼 자원을 효율적으로 이용하는 방법으로 PU (primary user)가 사용하지 않는 스펙트럼 홀의 크기를 예측하여 SU (secondary user)가 이용하는 방법이 있다. 본 논문은 SU의 서비스품질을 만족시키기 위하여, SU스펙트럼 홉핑호의 손실확률 (SHDP; spectrum hopping call dropped probability)을 최소화는 적응 호수락제어 기법을 제안한다. 이 방법은 호수락제어, 대역폭예측, 적응대역폭할당으로 구성된다. 예측기법은 스펙트럼홀의 크기뿐만 아니라, SU스펙트럼 홉핑호가 요구하는 대역폭크기를 함께 예측하며, 예약할 수 있는 자원의 크기가 부족할 때는 적응대역폭할당을 이용하여 SU스펙트럼 홉핑호의 손실확률을 최소화시킨다. 예측기법은 위너예측기법을 이용한다. 시뮬레이션을 통하여 제안한 방법의 성능을 기존방법과 비교하고, SHDP를 최소화 할 수 있음을 보인다.