• KSII Transactions on Internet and Information Systems (TIIS)
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• 제10권11호
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• pp.5209-5228
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• 2016

Device-to-device (D2D) communication underlaying cellular networks can bring significate benefits for improving the performance of mobile services. However, it hinges on elaborate resource sharing scheme to coordinate interference between cellular users and D2D pairs. We formulate a joint mode selection, link allocation and power control optimization problem for D2D communication sharing uplink resources in a multi-user cellular network and consider the efficiency and the fairness simultaneously. Due to the non-convex difficulty, we propose a three-step scheme: firstly, we conduct mode selection for D2D pairs based on a minimum distance metric after an admission control and obtain some cellular candidates for them. And then, a cellular candidate will be paired to each D2D pair based on fairness. Finally, we use Lagrangian Algorithm to formulate a joint power control strategy for D2D pairs and their reused cellular users and a closed-form of solution is derived. Simulation results demonstrate that our proposed algorithms converge in a short time. Moreover, both the sum rate of D2D pairs and the energy efficiency of cellular users are improved.

• 경영과정보연구
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• 제19권
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• pp.145-170
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• 2006

The purpose of this study is to examine the relationship between core factor of Knowledge Management(KM) and organizational effectiveness. The objects of study are middle manager in hosing construction and civil engineering and construction industry, and the sample size is 228. The core factor of KM and indicator of organizational effectiveness are drawn by literature survey. The core factors are classified into human capital, organizational capital, structural capital, (to put it concretely), job capability, human relation, strategy, information technology, process, sharing culture, leadership, measurement. The indicator of organizational effectiveness are measured by job satisfaction, organization loyalty, competitiveness. The main results of this study can be summarized as the following. 1) The core factor of KM has a positive relationship to organizational effectiveness. Especially, the core factor of sharing culture and leadership are strongly relationship with organizational effectiveness. 2) There was a high positive correlation between job satisfaction and organization loyalty. 3) Human, structural, and structural capital had a different affect on organizational effectiveness. 4) The more job position and educational level high, the more they recognized that KM is necessary for their organization. 5) Among the success factor in KM, the factor of job capability was well perceived to respondent. According to this study, we can analyzed the relationship between success factor and organizational effectiveness, and drawn the most influence success factor on organizational effectiveness. Concurrently, the results of this study will be useful guidelines for shaping the KM operation framework in construction industry.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2001년도 전력전자학술대회 논문집
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• pp.344-347
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• 2001

A high frequency resonant inverter consisting of three unit half-bridge serial resonant inverter used as power source of induction heating at high frequency is presented in this paper. As a output power control strategy, tine-sharing gate control method is applied. The analysis of the proposed circuit is generally described by using the normalized parameters. Also, according to the calculated characteristics value, a method of the circuit design and operating characteristics of the inverter is proposed. This paper proves the validity of theoretical analysis through the experiment. This proposed inverter show that it can be practically used in future as power source system for induction heating application, DC-DC converter etc.

• Journal of Power Electronics
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• 제16권1호
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• pp.111-120
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• 2016

Generally, a single phase H-bridge converter feeding a single primary track is employed in conventional inductive power transfer systems. However, these systems may not be suitable for some high power applications due to the constraints of the semiconductor switches and the cost. To resolve this problem, a novel dual coupled primary tracks IPT system consisting of two high frequency resonant inverters feeding the tracks is presented in this paper. The primary tracks are wound around an E-shape ferrite core in parallel which enhances the magnetic flux around the tracks. The mutual inductance of the coupled tracks is utilized to achieve adjustable power sharing between the inverters by configuring the additional resonant capacitors. The total transfer power can be continuously regulated by altering the pulse width of the inverters' output voltage with the phase shift control approach. In addition, the system's efficiency and the control strategy are provided to analyze the characteristic of the proposed IPT system. An experimental setup with total power of 1.4kW is employed to verify the proposed system under power ratios of 1:1 and 1:2 with a transfer efficiency up to 88.7%. The results verify the performance of the proposed system.

• 융합경영연구
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• 제9권2호
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• pp.33-43
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• 2021

Purpose: This study aims to verify sellers' economic incentives for voluntarily disclosing negative information in online markets and provide practical guidelines to online sellers in terms of whether, when, and how sharing low quality to buyers increase sales. Research design, data and methodology: Our model examines the number of bidders in Internet auctions to measure potential demand and uses count data analysis following previous studies that have also analyzed the number of bidders in auctions. After checking over-dispersion and zero-inflation in our data, we have run a Poisson regression to analyze the effect of sharing negative information on sales. Results: This study presents a counterintuitive result that low-quality sellers can increase their demand by fully disclosing negative information in an online market, if appropriate risk-reducing methods are employed. Our finding thus shows that there exists economic incentive for online sellers to voluntarily disclose negative information about their products, and that the context of transactions may affect this incentive structure as the incentive varies across product categories. Conclusions: As the positive impact of disclosing negative information has rarely been studied so far, this paper contributes to the literature by providing a unique empirical analysis on the impact of sellers' honesty on sales. By verifying economic incentives of disclosing low quality with actual online sales data, this study suggests practical implications on information disclosure strategy to many online sellers dealing with negative information.

• 한국정보통신학회:학술대회논문집
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• 한국정보통신학회 2021년도 춘계학술대회
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• pp.2-4
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• 2021

분산된 환경에서 머신 러닝의 학습 가중치를 공유하여 학습하는 방법은 훈련 데이터를 직접 공유하는 것이 아니기 때문에 안전한 것으로 여겨졌다. 하지만, 최근 연구에 따르면 악의적인 공격자가 공유된 가중치를 분석하여 원본 데이터를 완벽하게 복원할 수 있는 취약점이 발견되었다. Gradient Leakage Attack은 이러한 취약점을 이용해 훈련 데이터를 복원하는 공격 기법이다. 본 연구에서는 개별 장치에서 학습을 진행하고 가중치를 서버와 공유하는 학습 환경인 연합 학습 환경에서 해당 공격을 방어하기 위해 이산 코사인 변환에 기반한 이미지 변환 기법을 제시한다. 실험 결과, 우리의 이미지 변환 기법을 적용하면 공유된 가중치로부터 원본 데이터를 완벽하게 복원할 수 없다.

• 지능정보연구
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• 제15권1호
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• pp.15-30
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• 2009

인터넷을 통한 지식의 유통이 텍스트 형태의 지식뿐만 아니라 동영상 형태의 지식 유통으로 진화하고 있는 상황에서, UCC 지식 동영상을 공유하는 서비스가 나타나왔다. 본 논문은 동영상 UCC를 중심으로 지식 공유를 하는 'H' 사이트의 비즈니스 모델 평가 과정에서 수행된 고객 모델 분석사례를 보고한다. UCC 지식 동영상 공유 서비스는, 텍스트 형태의 지식공유 형태를 벗어나 새로운 형태인 동영상으로 지식을 공유한다는 점에서 불연속적 혁신의 형태를 띠며, 컨텐트 제공자와 컨텐트 소비자가 상호 매개되므로 직간접적 네트워크 효과가 일어나는 Value Network라는 특성을 가진다. 이렇게 불연속적 혁신이 일어나는 Value Network의 고객 모델 분석을 위해 첨단기술수용주기 이론인 캐즘 이론과 이를 심화 발전시킨 테크노그래픽스, 그리고 블루오션 전략에서 소개된 비고객 분석을 적용하여, UCC 지식 동영상 공유 사이트인 'H'사이트의 To-Be 고객 모델을 제안한다.

• 산경연구논집
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• 제9권3호
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• pp.57-68
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• 2018

Purpose - The purpose of this study is to classify that the quality factors for comparing the Visegrard Group with the Nordic Council have historical similarities against Germany and the Soviet Union. However, this is because in the integrated European market, the competitiveness possessed by the two groups of countries is invested in the priority order to grow. Research design, data, and methodology - The study was conducted on the research design, and the reason for trying to compare the competence of the automobile industry in the assessment of industrial capability is that the Visegrard Group focuses on automotive production and the Nordic Association focuses on the commercialization of the automobile(market). In this study, searching and quantifying indirect evidence was made through standards are more complementary in Europe since each country acts like the role of the European automotive industry for example, which is different from the realistic evaluation criteria, are more important than those of the United States(first in the world) or Germany(first in Europe). Results - The results of this study are as follows: In the global EV market U.S.(export: $ 2.62 billion /share: 36.7%), Germany($ 1.29 billion /18.1%), France($ 390 million /5.4%), United Kingdom($ 380 million /5.4%), and South Korea($ 320 million/ 4.4%). South Korea's share of the EV market is 4.4%, while TSI reaches at +0.9 which measures the comparative advantage of a specific commodity in the world trade market. There is great potential for evaluated as products processing in export competition. But, commercialization, standardization, and overall market expansion did not have a positive impact on global satisfaction. Conclusions - EVs put importance on various utilities. So this suggests that Korea's exports to the EU, including the Visegrard Group, should be more focused on marketability when illuminating with a sharing industrial system under the European Union. It is necessary to specialize in manufacturing and commercialization by country(region) to prepare sharing economy and blockchain in order to create a smart-sharing city linked on artificial intelligence, as the commercialization of electric vehicles, which will have a larger growth rate than that of manufacturing in the fourth revolutionary era.

• 디지털융복합연구
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• 제14권4호
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• pp.193-200
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• 2016

본 연구는 체험관광객의 관광 소셜미디어 채널의 중요도를 분석하였다. 선행연구를 바탕으로 관광 소셜미디어 채널의 요인을 관광커뮤니케이션 모델, 관광협업모델, 관광콘텐츠공유모델, 관광엔터테인먼트모델 등으로 분류하였다. 계층적 의사결정 방법인 AHP를 이용하여 실증 분석한 결과, 중요도의 측정결과로서 관광커뮤니케이션모델이 상대적으로 가장 주요한 요인으로 도출되었으며, 관광콘텐츠공유모델, 관광협업모델, 관광엔터테인먼트모델 등의 순으로 중요도가 높은 것으로 나타났다. 또한 관광 소셜미디어 채널의 유형 14개의 전체평가요소 우선순위에서 관광커뮤니케이션영역의 소셜네트워킹의 중요도가 가장 높게 나타났으며, 다음으로 관광협업영역의 소셜뉴스, 관광커뮤니케이션영역의 마이크로블로그 등의 순으로 나타났다. 분석결과를 통해 체험관광객의 소셜미디어 채널 효율성 증대 및 활용 전략에 기여할 수 있을 것이다.

• 한국콘텐츠학회논문지
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• 제15권5호
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• pp.550-559
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• 2015

한국의 만화산업은 오랜 역사에도 불구하고 뿌리 깊숙이 박혀 있는 불법복제물 시장으로 인해 아직까지 자생적인 건강한 생태계를 이루지 못하고 있다. 그간 불법복제물 시장 근절을 위한 다양한 연구가 있어왔으나 아직까지 이렇다 할 실효성을 인정받지 못하고 있는 상황이다. 이에 본 논문에서는 만화복제물 시장에 관한 연구를 이용자 관점에서 분석해 보고자 한다. 특히 불법복제물이지만 유료인 파일공유 사이트를 이용하는 이용자들을 대상으로 설문조사와 서면인터뷰를 통해 파악해 보았다. 이를 통해 이용자들의 도덕성과 사이트 이용 간의 상관관계는 어떠한지, 이용자들이 느끼는 파일공유 사이트의 인지된 편의성은 무엇인지 그리고 그들을 합법적인 만화 포털 사이트로 유인하기 위한 요인은 무엇인지를 중심으로 연구하였다. 그 결과, 만화 포털 사이트는 이용자들의 양성화를 위해 양질의 콘텐츠 확보, 결제 수단 등의 불편함 개선, 콘텐츠에 관한 자세한 정보 제공, 콘텐츠 구매 대여 방식 다양화 등의 구매 요인들을 개선할 필요가 있음을 알 수 있었다.