• 한국IT서비스학회지
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• 제8권1호
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• pp.193-202
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• 2009

Cloud computing emerges as a new computing paradigm which targets reliable and customizable services. The term builds on decades of research in virtual machine, distributed and parallel computing, utility computing, and more recently networking, web service, and software as a service. In this paper, we provide a seamless connection migration of web services. This is useful for cloud computing environment in which many client terminals have mobility. With the wireless internet facility, those mobile users can move place to place during internet communication. Therefore, we provide solutions to the two major problems in current virtualization based migration: communication failure problems and connection re-establishment. Communication channel flushing by zero window notification helps to resolve the communication failure problems and TCP port inheritance prevents connection re-establishment errors during socket reconstruction. Thus, our web service migration facility is now able to preserve open network connections, and even for server sockets. This is a highly transparent approach, in that we did not Introduce additional messages for channel flushing and did not make any modification to the TCP protocol stack. Experimental results show that the overhead due to connection migration of web services is almost negligible when compared with time to take the conventional web service migration.

• 커뮤니케이션학 연구
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• 제17권1호
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• pp.129-151
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• 2009

부부간 의사소통은 결혼 기간이 축적될수록 '공유된 경험세계'가 상대적으로 많은 반면 '친밀성'으로 인해 다양한 의사소통 문제들이 창출되는 산실이기도 하다. 따라서 부부간 의사소통은 표면적으로 매우 용이한 의사 소통 상황으로 비추어질 수 있지만 심층적으로 살펴보면 다양한 대인 커뮤니케이션(interpersonal communication)의 문제가 산재해 있음을 볼 수 있다. 이 연구는 한국사회의 부부간 의사소통 행태를 각 세대별로 나누어 그 특성을 탐색해보고, 결혼생활이 축적됨에 따라 나타날 수 있는 부부간 의사소통 행태의 변화 추이를 살펴보는데 중점을 두었다. 이러한 연구목적을 달성하기 위하여 20대, 30대, 40대, 50대 부부, 즉 연령 동기자 그룹을 대상으로 대인 커뮤니케이션과정의 5가지 차원-개방적 태도 차원, 문제 해결 차원, 의사 표현 차원, 경청(傾聽) 차원, 피드백 차원에서 설문조사를 진행하여 그 결과를 분석해보고자 하였다. 분석 결과 부부간 의사소통 행위의 특성이 각 세대별로 파악 되었으며, 다시 의사 종단 분석을 통하여 개방적 태도 차원, 문제 해결 차원, 의사 표현 차원, 경청 차원, 피드백 차원의 부부간 의사소통 행위가 변천하는 과정을 추적해볼 수 있었다.

• 한국경영과학회지
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• 제29권3호
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• pp.145-155
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• 2004

The design of a communication network has long been a challenging optimization problem. Since the optimal design of a network topology is a well known as a NP-complete problem, many researches have been conducted to obtain near optimal solutions in polynomial time instead of exact optimal solutions. All of these researches suggested diverse heuristic algorithms that can be applied to network design problems. Among these algorithms, a simulated annealing algorithm has been proved to guarantee a good solution for many NP-complete problems. in applying the simulated annealing algorithms to network design problems, generating mechanisms for initial solutions and candidate solutions play an important role in terms of goodness of a solution and efficiency. This study aims at analyzing these mechanisms through experiments, and then suggesting reliable mechanisms.

• 한국정보통신학회:학술대회논문집
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• 한국해양정보통신학회 2005년도 춘계종합학술대회
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• pp.213-216
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• 2005

1992년 새로 도입된 GMDSS(Global Maritime Distress and Safety System: 세계 해상 조난 및 안전 제도)는 기존의 조난통신 제도를 새로운 정보통신기술을 사용하여 획기적으로 개선하였으며 쉽고 자동화된 조난신호 발신 체제 및 효율적이고 범세계적인 수색구조 통신망을 구축하였음에도 불구하고 여러 가지 문제점을 나타내고 있다. 협약선과 비협약선의 조난통신 이원화 문제, 다량의 허위 조난신호 발생에 따른 수색구조의 어려움, 운용능력의 저하로 인한 조난통신 대응체제의 부재 등은 GMDSS 제도의 도입에 따른 조난통신의 대표적인 문제점들이다. 본 논문에서는 우리나라의 관점에서 본 GMDSS 조난통신 제도의 문제점 들을 분석하고 이에 대한 개선방안을 제시하고자 한다.

• 경영과학
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• 제10권1호
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• pp.23-39
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• 1993

In this study, potential Communication Satellite Application Services (CSASs) that are suitable for our communication environment have been identified through a detailed analysis of the CSASs offered in advanced countries. The existing demand forecast based on the defined CSAS category has been improved, and the transponder assignment policy has also been recommended. Managerial problems rather than technical ones for KOREASAT project have mainly been addressed and tackled in this study. For the successful implementation of the domestic communication satellite system, these two problems should be solved simultaneously. Therefore, future research that includes technical as well as managerial issues is expected to come out soon.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2004년도 ICEIC The International Conference on Electronics Informations and Communications
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• pp.249-253
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• 2004

Wavelet transform (WT) has attracted most engineers and scientists because of its excellent properties. The coherence of practical approach and a theoretical basis not only solves currently important problems, but also gives the potential of formulating and solving completely new problems. It has been show that multi-resolution analysis of Wavelet transforms is good solution in speech analysis and threshold of wavelet coefficients has near optimal noise reduction property for many classes of signals. This paper proposed applications of wavelet in speech processing: pitch detection, voice-unvoice (V -UV) decision, denoising with the detailed algorithms and results.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2006년도 하계종합학술대회
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• pp.785-786
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• 2006

Recently, Healthcare system has not been standardized and has been developed as an embedded system lacking interoperability. We are finally going to face such problems as having excessive load in using network caused by the uncontrolled spread of system and un-guaranteed interoperability among the heterogenous systems. We suggest the possibility that OSGi (Open Service Gateway initiative : the international standardization of service middleware) can be accepted as a solution for the above problems.

• 정보통신설비학회논문지
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• 제10권1호
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• pp.40-45
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• 2011

As increasing the importance of renewable energy recently, the scale of a wind power plant is increasing to the number of GW scale and specially, it is trend to move from onshore to offshore to use the higher quantity and quality of wind. Consequently to meet the trend, it is largely considered the importance of communication protocol to control and monitor remotely. But, because the communication protocol between the control center and a wind turbine has been independently developed by each wind turbine vendor, it is absence of the compatibility and extensibility when the heterogeneous wind turbines are installed in the wind farm. The IEC 61400-25 is the specifying standard for these problems in Europe. In this paper, we will show the state of these problems and present a new structure of communication based on the IEC 61400-25 to get the compatibility and extensibility between a control center and wind turbines.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2002년도 ITC-CSCC -2
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• pp.967-970
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• 2002

Multihop wireless networks consist of mobile terminals with personal communication devices. Each terminal can receive a message from a terminal and send it to the other terminal. In this paper, we discuss edge coloring problems related to multihop wireless networks. We show some relations about the problems.

• 항공우주정책ㆍ법학회지
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• 제12권
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• pp.386-394
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• 2000