• 한국인터넷방송통신학회논문지
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• 제15권4호
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• pp.33-41
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• 2015

기계간의 통신을 지칭하는 M2M(Machine to Machine) 환경은 최근 융합 서비스의 등장과 동시에, 수많은 장치의 활용으로 인한 전반적인 보안 요구사항이 증가하고 있으며, 관련 각 표준화단체는 이러한 장치간의 보안요구사항을 충족하기 위해 각 영역별 보안기술에 대해 표준화를 진행 중에 있다. 본 논문에서는 다수의 M2M 장치들 간에 상호인증을 위한 키 관리 방법에 대해 제안한다. 본 논문에서 제안하는 방법은 M2M 디바이스와 서버 간에 상호인증을 기반으로 서비스 영역이 다른 디바이스 간에 안전한 데이터 공유를 수행한다. 제안하는 기법은 현재 M2M 표준의 보안 요구사항에 따른 안전성을 충족하고, 기존 연구에서 제안된 인증기술보다 성능이 향상된 타원곡선 알고리즘 기반 프로토콜을 사용하여 효율성을 강화하였다.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제7권5호
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• pp.1236-1251
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• 2013

Sharing geo-tagged photos has been a hot social activity in the daily life because these photos not only contain geo information but also indicate people's hobbies, intention and mobility patterns. However, the present raw geo-tagged photo routes cannot provide information as enough as complete GPS trajectories due to the defects hidden in them. This paper mainly aims at analyzing the large amounts of geo-tagged photos and proposing a novel travel route restoring method. In our approach we first propose an Interest Measure Ratio to rank the hot spots based on density-based spatial clustering arithmetic. Then we apply the Hidden Semi-Markov model and Mean Value method to demonstrate migration discipline in the hot spots and restore the significant region sequence into complete GPS trajectory. At the end of the paper, a novel experiment method is designed to demonstrate that the approach is feasible in restoring route, and there is a good performance.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제11권6호
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• pp.3029-3045
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• 2017

The main processes of a cognitive radio system include spectrum sensing, spectrum decision, spectrum sharing, and spectrum conversion. Experimental results show that these stages introduce a time delay that affects the spectrum sensing accuracy, reducing its efficiency. To reduce the time delay, the frequency spectrum prediction was proposed to alleviate the burden on the spectrum sensing. In this paper, the deep recurrent neural network (DRNN) was proposed to predict the spectrum of multiple time slots, since the existing methods only predict the spectrum of one time slot. The continuous state of a channel is divided into a many time slots, forming a time series of the channel state. Since there are more hidden layers in the DRNN than in the RNN, the DRNN has fading memory in its bottom layer as well as in the past input. In addition, the extended Kalman filter was used to train the DRNN, which overcomes the problem of slow convergence and the vanishing gradient of the gradient descent method. The spectrum prediction based on the DRNN was verified with a WiFi signal, and the error of the prediction was analyzed. The simulation results proved that the multiple slot spectrum prediction improved the spectrum efficiency and reduced the energy consumption of spectrum sensing.

• 기술경영경제학회:학술대회논문집
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• 기술경영경제학회 1997년도 제12회 동계학술발표회 논문집
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• pp.104-130
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• 1997

This study empirically examined different patterns of collaborative R&D project with their key success factors(KSFs), using data from 80 projects in the Korean electronic parts industry The patterns in this study were categorized into 4 types by two criteria : product types(off-the-shelf/unique) and project initiator (focal/partner). The bivariate relationships revealed that project characteristics (technological complexity, demand certainty), partner characteristics(the number of partners, precious experience), process characteristics (participation in the project formulation, specificity of the collaboration process and outcomes) appear to be different among four types of collaboration. Furthermore, this study found that each type of collaborative R&D projects has different KSFs for their commercial success. The KSFs of type 1 (off-the-shelf product and focal organization initiation), for instance, include the strategic importance of the project, the problem solving performance of the focal organization while those of type 4(unique product and partner initiation) are technological complexity, demand certainty, reliability of partner relationship, specificity of the goals, specificity of the process and outcomes, information sharing. Finally, based on this empirical results, managerial, policy, and theoretical implications of the study were discussed.

• 한국정보기술응용학회:학술대회논문집
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• 한국정보기술응용학회 2005년도 6th 2005 International Conference on Computers, Communications and System
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• pp.139-142
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• 2005

Recently research interest in Knowledge Management (KM) has grown rapidly. Companies regard intellectual capital as important asset and strive to deploy KM in an organization to gain a competitive edge. Many organizations currently engage in knowledge management in order to leverage knowledge both within their organization and externally to their shareholders and customers. Most of the previous research related to KM are dedicated to investigate the role of information technology in extracting, capturing, sharing, coverting organizational knowledge. Knowledge workers, however, are paid less attention though they are the key players in KM activities such as knowledge creation, dissemination, capture and conversion. We regard knowledge workers as a major component of KM and starting point of understanding organizational knowledge activities. Therefore we adopt a method to understand and analyze knowldge workers' social relationships. In this paper we investigate Social Network Analysis (SNA) as a tool for analyzing knowledge network. We introduce the basic concept of SNA and suggest a framework for implementing knowledge network by explaining how SNA can be used for analyzing knowledge network. We also propose a numerical method for identifying knowledge workers using SNA after classifying knowledge workers. The suggested method is expected to help understanding key knowledge players within an organization.

• 디지털융복합연구
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• 제12권12호
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• pp.249-255
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• 2014

최근 트위터, 페이스북 등과 같은 소셜 네트워크 서비스(Social Network Service, SNS)의 확산과 더불어 정보의 생성 및 공유가 활발히 이루어지고 있다. 이러한 SNS 매체들을 통해 생산하는 많은 데이터를 활용하기 위해 축적된 데이터로부터 의미 있는 정보를 추출해 내는 기술의 필요성이 대두되고 있으며, 데이터 마이닝 기법을 이용하여 의미있는 지식을 찾아낸다. 특히, 다양한 형태의 방대한 자료들로부터 표출되는 의견, 정책, 성향, 감정 등 대중의 집단지성에 나타난 일반적인 감정분석이 활용되고 있다. 본 논문에서는 대중들이 SNS를 통해 작성한 사용자들의 짧은 문장에 함축된 단어와 단어들 간의 연관성을 이용하여 문장 내 감정 상태를 예측하고 사용자의 감정에 따른 적절한 답변이나 추출한 감정과 유사한 트윗글이나 영화 등을 추천하는데 사용될 수 있는 방법을 제안한다.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제9권6호
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• pp.1996-2013
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• 2015

This paper considers a scenario that more D2D users exist in the cell, they compete for cellular resources to increase their own data rates, which may cause transmission interference to cellular users (CU) and the unfairness of resource allocation. We design a resource allocation scheme for selfish D2D users assisted by cooperative relay technique which is used to further enhance the users' transmission rates, meanwhile guarantee the QoS requirement of the CUs. Two transmission modes are considered for D2D users: direct transmission mode and cooperative relay transmission mode, both of which reuses the cellular uplink frequency resources. To ensure the fairness of resource distribution, Nash bargaining theory is used to determine the transmission mode and solve the bandwidth allocation problem for D2D users choosing cooperative relay transmission mode, and coalition formation game theory is used to solve the uplink frequency sharing problem between D2D users and CUs through a new defined "Selfish order". Through theoretical analysis, we obtain the closed Nash bargaining solution under CUs' rate constraints, and prove the stability of the formatted coalition. Simulation results show that the proposed resource allocation approach achieves better performance on resource allocation fairness, with only little sacrifice on the system sum rates.

• 유통과학연구
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• 제12권3호
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• pp.85-98
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• 2014

Purpose - This study primarily aims to represent the current trend of research on CPFR as a promising supply chain collaboration program and proposes a new framework for analyzing any collaboration programs in terms of three key collaborative features. Research design, data, and methodology - This study employs a literature review of selected studies that conduct research on CPFR. CPFR is analyzed based on the proposed framework that characterizes collaboration programs in terms of three key collaborative features. Results - The analysis based on the proposed framework reveals that the current form of CPFR continues to have some collaborative features that are not fully utilized to create an advanced collaboration program. The literature review indicates that most past studies ignore critical issues including the dynamic nature of the multiple-stage supply chain system and negotiation process for collaborative agreement in CPFR implementation. Conclusions - Results indicate that CPFR can become a better supply chain collaboration program by incorporating coordinative cost payment and joint decision making processes. Based on observations on the existing literature of CPFR, this study indicates several important issues to be addressed by future studies.

• 한국전자거래학회지
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• 제9권2호
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• pp.87-108
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• 2004

기존의 건설산업에서는 건설산업의 전 생명주기 동안 발생하는 모든 설계도면과 시방서 및 문서를 방대한 분량의 종이로 관리하여 왔다. 그 결과 유사 공사 실적자료의 재사용, 설계자와 시공자간의 정보교환ㆍ공유에 있어 공사의 실적저하, 예산낭비 등의 문제를 가져왔다. 이러한 문제를 해결하기 위하여 건축 정보의 교환ㆍ공유에 기존의 형식인 종이대신 전자화 된 도면과 문서를 사용하도록 하는 업무개선의 요구가 있어왔고, 이러한 문제를 총체적으로 해결하기 위하여 정부차원의 건설분야 전자거래프로그램이 요구되게 되었다. 본 논문은 건설CALS/EC(Continuous Acquisition and Life Cycle Support/Electronic Commerce)와 관련된 요소기술의 국내외적인 적용사례를 바탕으로 하여 도면전자납품을 위한 건설 CALS/EC에서 표준기술이 되는 요소기술의 활용방안과 향후 개발 방향에 관하여 제시해 보고자 한다.

• 한국정보통신학회:학술대회논문집
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• 한국정보통신학회 2012년도 추계학술대회
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• pp.237-240
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• 2012

본 논문에서는 국내 표준(KS)으로 제정된 블록암호 알고리듬 ARIA의 하드웨어 구현을 제안한다. 제안된 ARIA 암 복호 코어는 표준에 제시된 세 가지 마스터 키 길이 128/192/256-비트를 모두 지원하도록 설계되었으며, ECB, CBC, CTR, OFB와 같은 4개의 암호 운영모드를 지원한다. 회로의 크기를 줄이기 위해 키 확장 초기화 과정과 암 복호 과정에 사용되는 라운드 함수가 공유되도록 설계를 최적화 하였다. 설계된 ARIA 암 복호 코어를 FPGA로 구현하여 하드웨어 동작을 검증하였으며, 1.07 Gbps@167 MHz의 성능을 갖는 것으로 평가되었다.