• 컴퓨터교육학회논문지
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• 제13권5호
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• pp.1-13
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• 2010

2007년 개정 교육과정의 시행에 따라 새로운 정보 교과서가 2010년부터 중학교 1학년에 적용된 뒤 중등학교로 점차적으로 확대 시행된다. 그러나 정보 교과서 선택을 위한 평가 관련 연구가 미미하며, 특히 중학교 정보 교과서에 대한 선택 기준 개발은 전무한 상태이다. 따라서 본 논문에서는 중학교 정보 교과서 선택 기준의 제안을 연구 목표로 하며, 그 세부적인 연구 내용은 다음과 같다. 첫째, 기존의 교과서 평가 관련 연구들을 일반 교과서 선택 준거, 탐구성에 대한 교과서 분석법, 기존 중등 정보 교과서를 분석한 선행 연구로 나누어 분석한 뒤, 중학교 정보 교과서를 위한 선택 기준을 제안한다. 둘째, 제안된 정보 교과서 선택 기준과 타 평가준거를 사용하여 중학교 1학년 정보 교과서 5종을 비교 분석하였다. 끝으로 본 논문은 중학교 정보 교과서에 대한 선택 기준 제안과 비교 분석을 통해 정보 교과서의 선정에 도움을 주고, 향후 정보 교과서의 평가 연구를 위한 개발에 구체적인 방향을 제시할 수 있을 것으로 기대된다.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제10권3호
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• pp.950-975
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• 2016

Device-to-Device (D2D) communication underlaying cellular networks is a promising add-on component for future radio communication systems. It provides more access opportunities for local device pairs and enhances system throughput (ST), especially when mobile relays (MR) are further enabled to facilitate D2D links when the channel condition of their desired links is unfavorable. However, mutual interference is inevitable due to spectral reuse, and moreover, selecting a suitable transmission mode to benefit the correlated resource allocation (RA) is another difficult problem. We aim to optimize ST of the hybrid system via joint consideration of mode selection (MS) and RA, which includes admission control (AC), power control (PC), channel assignment (CA) and relay selection (RS). However, the original problem is generally NP-hard; therefore, we decompose it into two parts where a hierarchical structure exists: (i) PC is mode-dependent, but its optimality can be perfectly addressed for any given mode with additional AC design to achieve individual quality-of-service requirements. (ii) Based on that optimality, the joint design of MS, CA and RS can be viewed from the graph perspective and transferred into the maximum weighted independent set problem, which is then approximated by our greedy algorithm in polynomial-time. Thanks to the numerical results, we elucidate the efficacy of our mechanism and observe a resulting gain in MR-aided D2D communication.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제11권7호
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• pp.3524-3542
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• 2017

In a single-source and multi-relay amplify-forward (AF) cooperative network, the outage probability and the power allocation are two key factors to influence the performance of an entire system. In this paper, an optimized AF relay selection by an exclusive method and near optimal power allocation (NOPA) is proposed for both good outage probability and power efficiency. Given the same power at the source and the relay nodes, a threshold for selecting the relay nodes is deduced and employed to minimize the average outage probability. It mainly excludes the relay nodes with much higher thresholds over the aforementioned threshold and thus the remainders of the relay nodes participate in cooperative forwarding efficiently. So the proposed scheme can improve the utility of the resources in the cooperative multi-relay system, as well as reduce the computational complexity. In addition, based on the proposed scheme, a NOPA is also suggested to approach sub-optimal power efficiency with low complexity. Simulation results show that the proposed scheme obtains about 2.1dB and 5.8dB performance gain at outage probability of $10^{-4}$, when compared with the all-relay-forward (6 participated relays) and the single-relay-forward schemes. Furthermore, it obtains the minimum outage probability among all selective relay schemes with the same number of the relays. Meanwhile, it approaches closely to the optimal exhaustive scheme, thus reduce much complexity. Moreover, the proposed NOPA scheme achieves better outage probability than those of the equal power allocation schemes. Therefore, the proposed scheme can obtain good outage probability, low computational complexity and high power efficiency, which makes it pragmatic efficiently in the single-source and multi-relay AF based cooperative networks.

• 대한전자공학회논문지TC
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• 제47권11호
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• pp.24-29
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• 2010

선택적 중계 기법은 수신 복잡도가 낮으면서도 선택 다이버시티로 인하여 성능 향상을 도모할 수 있는 협력 통신 시스템의 전송 기법 중 하나이다. 본 논문에서는 이 시스템의 오차 확률을 최소화 할 수 있는 선형 전처리 기술을 다룬다. 전 채널 상태 정보가 모든 단말에서 이용 가능하다는 가정 하에, 수신 신호의 평균 제곱 오차를 최소화하기 위한 송신 및 중계 전처리 필터를 제안한다. 중계 전송을 위한 최적의 송신 및 중계 전처리 필터는 수식적으로 표현하기 어렵고 반복 연산을 요구하므로 이를 단순화한 기법을 적용한다. 게다가, 고정된 신호 대 잡음비의 임계치를 사용하는 기존의 선택적 중계 기법과 달리 직접 경로와 중계 경로에서의 신호 검출 후 최소 신호 대 잡음비를 비교하여 더 큰 값을 갖는 경로를 전송 경로로 선택하는 기법을 소개한다. 모의실험을 통하여 제안한 선택 중계 기법이 기존의 중계 기법 및 선택적 중계 기법보다 우수한 성능을 보임을 확인할 수 있다.

• 한국의상디자인학회지
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• 제13권4호
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• pp.139-151
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• 2011

Since personality lead to relatively consistent responses to one's own environment, consumers' distinct personality influences their buying behavior. In order to understand the relationship between consumer's personal characteristics and purchase behavior, the study investigated the effect of consumers' personality trait on the clothing selection criteria and preferred clothing image. Survey was utilized to collect the data and subjects were 333 high school students. Measures consisted of three main constructs: Consumer's extroversion and openness based on the Big-Five personality trait, clothing selection criteria, and preferred clothing image. The data were analyzed using PRELIS 2, LISREL 8.8, and SAS 9.2. The subjects was classified into three groups; Group 1 was a group of intermediate-level in openness and extroversion while Group 2 was a group of high-level in both personality traits. Group 3 was a group of high-level in openness but of low-level in extroversion. Clothing selection criteria were confirmed to have five constructs: other-directed, aesthetic, fashion & conformity-oriented, brand-oriented, and practical. In the buying situation, Group 1 prioritized fashion & conformity-oriented and brand-oriented criteria but regarded other-directed and aesthetic as less important than other groups did. Group 2 considered that all of the clothing selection criteria were important except practical. "The were six factors in the clothing image: elegance, simple, ethnic, masculine, active, and modem. The result showed a significant difference between groups in preferred clothing images. Group 2 liked most of the clothing images but group 3 did not. Group 3 preferred simple clothing image more than masculine or ethnic ones. Overall, the study concluded that the openness and extroversion of Big-Five personality traits could serve as a predictor of clothing selection criteria and preferred clothing image.

• 정보교육학회논문지
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• 제22권4호
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• pp.491-500
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• 2018

4차 산업혁명시대에 필요한 인재는 특정 학문에 종속되는 것이 아니라 여러 학문들을 융합할 수 있어야 한다. 초등학생들의 경우에 다양한 변화의 가능성이 있기 때문에 융합적인 사고를 갖는 것이 중요하다. 따라서 초등학교 영재를 선발할 때에도 융합 영재 학생들을 선발하고 있다. 본 연구에서는 융합 영재 학생들을 선발할 때에 창의적인 문제 해결력, 서류 평가, 면접 요소들이 학생 선발에 어떤 영향을 미치는지 알아본다. 연구 결과 창의적 문제해결력이 선발에 미치는 영향력이 가장 높다. 5학년의 경우에는 창의적인 문제 해결력과 서류 평가가 선발에 영향을 미치고, 4학년의 경우에는 창의적인 문제 해결력과 면접이 선발에 영향을 미치고. 여학생들은 창의적인 문제해결력과 서류 평가가 선발에 영향을 미친다는 것을 알 수 있었다. 그룹별로 차이를 분석한 결과, 성별에서는 서류 평가에서 성별로 차이가 있었고, 학년별 유의미한 차이점이 없다는 것을 알 수 있었다.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제7권1호
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• pp.99-118
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• 2013

Electrocardiograms (ECGs) are widely used by clinicians to identify the functional status of the heart. Thus, there is considerable interest in automated systems for real-time monitoring of arrhythmia. However, intra- and inter-patient variability as well as the computational limits of real-time monitoring poses significant challenges for practical implementations. The former requires that the classification model be adjusted continuously, and the latter requires a reduction in the number and types of ECG features, and thus, the computational burden, necessary to classify different arrhythmias. We propose the use of adaptive learning to automatically train the classifier on up-to-date ECG data, and employ adaptive feature selection to define unique feature subsets pertinent to different types of arrhythmia. Experimental results show that this hybrid technique outperforms conventional approaches and is therefore a promising new intelligent diagnostic tool.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제10권8호
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• pp.3585-3601
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• 2016

The error rate performance of circularly distributed antenna system is studied over Nakagami-m fading channels, where a dual-channel receiver is employed for the quadrature phase shift keying signals detection. To mitigate the Co-Channel Interference (CCI) caused by the adjacent cells and to save the transmit power, this work presents remote antenna unit selection transmission based on the best channel quality and the maximized path-loss, respectively. The commonly used Gaussian and Q-function approximation method in which the CCI and the noise are assumed to be Gaussian distributed fails to depict the precise system performance according to the central limit theory. To this end, this work treats the CCI as a random variable with random variance. Since the in-phase and the quadrature components of the CCI are correlated over Nakagami-m fading channels, the dependency between the in-phase and the quadrature components is also considered for the error rate analysis. For the special case of Rayleigh fading in which the dependency between the in-phase and the quadrature components can be ignored, the closed-form error rate expressions are derived. Numerical results validate the accuracy of the theoretical analysis, and a comparison among different transmission schemes is also performed.

• 시스템엔지니어링학술지
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• 제9권1호
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• pp.55-63
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• 2013

Nuclear power plant site selection is a complex process and its successful completion is a critical milestone in the NPP development cycle. Proper siting of NPP will ensure public health and safety, environmental conservation, reduced project failure risks and a smooth NPP development process among other benefits. The objective of this paper is to demonstrate the application of systems engineering to the problem of NPP siting in Kenya. The siting process demonstrated in this paper includes stakeholder need analysis where stakeholders are identified and their needs concerning NPP site are elicited and converted into system functional requirements. A value model is then developed and potential sites iteratively subjected to three types of criteria i.e. exclusionary criteria, avoidance criteria and suitability criteria. This process is used to identify the candidate sites. An additive value model; multiple objectives Decision Analysis (MODA) is then used to calculate candidate solutions values. The site with the highest solution value score is selected. Sensitivity studies using different criterion weight sets (thereby reflecting different viewpoints) can be conducted to assess their effect on the selection of a preferred site and thereby lend additional credibility to the decision process.

• Management Science and Financial Engineering
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• 제11권3호
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• pp.79-93
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• 2005

Despite the fact that the sourcing process in B2B e-Marketplaces is one of the most important tasks, the evaluation and selection process of suppliers have been ad-hoc based and mainly dependent on the experience of sourcing managers' subjective knowledge. To remedy the problem, we developed a decision support System (called Wise - I) that helps sourcing managers evaluate suppliers in a more systematic way. The system reflects company's strategy and know-how by adopting company enforced weighted scores for different factors and employing a more scientific method of considering factors other than price and on-time delivery rate, utilizing the AHP method. This paper reports the effectiveness of the system as well as the detailed description of the system. To investigate the effectiveness of the system, we collected information through interview and questionnaire survey. The information was also augmented through the firm key index system, which monitors average delivery lead time and on-time delivery rate. The result indicates that the system leads to the efficiency of purchasing section and the transparency of buying process, therefore reduces delivery time and cost.