• The Journal of Korean Institute of Communications and Information Sciences
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• v.40 no.9
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• pp.1808-1818
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• 2015

Recently, the wind power has experienced great attentions and growths among many renewable energy sources. To increase the power generation performance and economic feasibility, the size of wind turbine (WT) is getting bigger and most of wind power plants are being constructed on offshore. Therefore, the maintenance cost is relatively high because boats or helicopters are needed operators to reach the WT. In order to combat this kind of problem, remote monitoring and control system for the WT is needed. In this paper, the small-scale WT monitoring and control system is implemented using wireless sensor network technologies. To do this, sensor devices are installed to measure and send the WT status and control device is installed to receive control message for specific operation. The WT is managed by control center through graphic user interface (GUI) based monitoring and control software. Also, smart device based web-program is implemented to make the remote monitoring of the WT possible even though operators are not in control room.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.13 no.2
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• pp.46-54
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• 1999

In recent years, the electromagnetic enviroments are varied with the increase of power consumption and the spread of hoosehold electric appliances. Most of the interests to date have concentrated in the area of human health effects associated with exposure to power frequency electric and rmgretic fields, and thus the precise measurement and analysis are required. In this paper, the measurements and analysis of the extremdy low frequency(ElF) electric and magnetic fields produced by actual 22.9[kV] distribution lines were performed. The experiIrents have been carried rot by lateral rrofile, and the thooretical analyses were made by use of FIELDS program fer the sake of comparison with the experimental data. Electric and magnetic field intensity were strong under power distrib.rticn lines, and were inversely proportional to lateral distance. The pufiles of electric and magnetic fields were M and $\bigcap$ shapes, respectively. and the rreasured data were good in agreemnt with the thooretical results. Both the electric and magnetic field intensity were iocreased with increasing the measurement height.height.

• Journal of the Society of Disaster Information
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• v.16 no.3
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• pp.458-471
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• 2020

Purpose: In Korea, the frequency and frequency of earthquakes are increasing every year. Therefore, the purpose of this study was to compare and analyze the characteristics and examples of earthquakes in Korea and Japan, and to propose improvements to the earthquake prevention policy in Korea. Method: In this study, we investigate and evaluate Japan's response in two cases: the Kobe earthquake and the East Japan earthquake. After surveying and evaluating the nation's countermeasures in the two events, Gyeongju and Pohang, they were compared. Result: When comparing recovery systems in Korea and Japan, there were significant differences in plans for restoration of road transport networks, regional disaster prevention plans, and the introduction of Conclusion: considering the physical distance between Korea's earthquake-prone areas and the capital, the government should quickly come up with countermeasures to ensure that immediate earthquake response in the region is enhanced through the detailed establishment of the Functional Continuity Plan (COOP), and that administrative functions will function normally in the event of a disaster through the introduction of the administrative BCP concept.

• Journal of the Korea Computer Graphics Society
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• v.4 no.1
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• pp.89-100
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• 1998

A multi-user virtual reality system supports shared environments for concurrent accesses by multiple users. The performance of these systems depends heavily on the network environments. This paper experiments an effective network model for shared virtual environments. This model has a middle layer called groups placed between the server and its clients, and the tasks of server are distributed to these groups. Using groups solves some of the problems of existing systems such as lack of scalability, message overheads, and latency due to message passing among locally communicating entities in the virtual environment. Some experiments show lower overhead than existing distributed virtual environment systems in WAN as well as LAN environments. This model also supports a method that can be used to construct application specific network environments using message handler which allows user-defined message formats.

• The KIPS Transactions:PartD
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• v.10D no.3
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• pp.375-386
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• 2003

A rapid growth of mobile devices and a proliferation of wireless networks lead to changing the existing environment into a mobile environment. Expansion of mobile environment makes a pressing need of mobile databases, and there are several solutions to achieve it. But they still accompany with some problems. Especially, the current synchronization server that manages consistently many mobile database management systems is based on the centralized method to synchronize data between the mobile database systems. It is the major factor that causes the lower performance of the whole system. Furthermore, the fault tolerance has not been considered in the existing systems. Therefore, we suggest the mobile agent-based mobile database system in order to resolve the problems. The system, we propose in this paper, provides the high-performance of the whole system by mobile grouping, and also may support a fault-tolerance management method.

• Proceedings of the Technology Innovation Conference
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• 2005.08a
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• pp.141-167
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• 2005

본 연구의 목적은 우리나라보다 앞서 실시하고 있는 일본의 산업 클러스터 계획 프로젝트의 거시적인 현황과 가장 성공적이라고 하는 TAMA클러스터의 사례를 분석하여 향후 우리나라 클러스터 정책 시행에 필요한 시사점을 얻는데 있다. 특히 TAMA클러스터의 성공은 이를 직접 관리하고 있는 민간차원의 중개조직인 TAMA산업활성화협회의 운영전략을 집중적으로 분석하여 봄으로써 도입 가능성에 대한 진단과 정책적 제안을 하고자 한다. 첫째, 일본의 19개 지역별 산업 클러스터 계획의 공통점은 어느 것도 도도부현의 영역을 초월한 광역적인 클러스터를 형성하고 있다. 광역단위의 집적은 상대적으로 클러스터 계획에 대한 중요성과 실행주체를 망각하기 쉬워 실패할 가능성이 비교적 높을 수 있다 이러한 점을 극복하기 위한 대안으로 산학연의 3주체 간 연계를 주로 담당하는 민간중심의 중개조직을 두어 운영하고 있다. 둘째, 클러스터 정책기간은 시작에서 자립까지 20년을 상정하고, 제1기 5년간은 산업 클러스터 네트워크 구축기, 제2기 5년은 산업 클러스터 성장기 그리고 마지막 제3기 10년은 산업 클러스터의 자율적 발전기로서 책정되어 수행하는 것이 바람직하다고 보고 있다. 셋째, 개별적인 산업 클러스터의 비전, 목표, 중장기 전략의 올바른 수립이 필요한데 백화점식이 아닌 대상산업 및 대상 주체에 대한 선택과 집중의 전략성이 엿보인다. 넷째, 정책 대상의 범위는 연구개발에서 판매에 이르기까지 전 비즈니스 프로세스를 대상으로 하고 있으며 클러스터 관련 정책수행 주체들의 정책조율, 중복 투자의 회피 그리고 효과적인 정책을 시행하기 위하여 수평적인 연락망과 협의체를 구성하고 있다. 다섯째, TAMA협회는 전통적인 동종 산업중심의 협회 기능과는 달리 제품개발형 중소$\cdot$중견기업을 대상으로 신기술개발과 신사업 전개를 위한 전략적 지원을 하고 있다. 비교적 개별적인 기술개발 능력은 물론 독자적인 마케팅 능력을 갖고 있어 일반적인 보호 대상자로서의 중소기업과는 차원이 다르며 기존의 하청관계라는 수직적 의존적인 존재가 아니라 세계적으로 니치 시장에서 경쟁력을 가지고 있는 대기업과 대등한 입장의 우량기업이라는 것이 특징이다. 여섯째, 지금까지는 기업을 지원하는 각 기관들이 각각 독자적으로 운영하여 경영자원의 분산과 이용으로 수혜자인 중견$\cdot$중소기업의 입장은 물론 지방자치단체 및 중앙정부의 차원에서 분석하여 볼 경우 경영자원의 Critical Mass를 확보하기 어려웠다. TAMA협회는 네트워크 조직으로서 주로 소프트적인 지원을 통하여 원활하게 수행하고 있음. 정보와 네트워크만을 가지고 조직간 관계를 중개하는 가벼운 네트워크 조직으로서 운영하는 방법은 한국의 경우에도 적용이 가능하며 매우 유용하다고 생각된다.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2018.05a
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• pp.565-566
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• 2018

Conventional IoT systems are centralized systems that process information from the server on the device and most of them use a wireless LAN network. However, There may arise a problem of when the signal of the wireless LAN network is not reached, the IoT product can not be used and accessing a wireless LAN network having a stronger signal. In order to solve this problem, this paper proposes a system that a method to maintain stability of IoT products by using repeaters, and to manage IoT products and reduces the burden on the server by processing part of the data processed by the server in the repeater. The problems caused by the signal of the wireless LAN network can be solved by amplifying the signal with the repeater, and the overloading problem that can occur in the server can be solved by controlling the repeater's IoT product connected thereto to reduce the server usage.

• The Transactions of the Korea Information Processing Society
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• v.5 no.1
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• pp.73-85
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• 1998

Today's Software Systems are becoming bigger, larger and more complex than ever before. To develop largerscale projects, it is required that many experts of different fields participate and cooperate in the same project. So, it is an applied area of CSCW(Computer Supported Cooperative Works} that centers around methodologies and tools that enable cooperative works by geographically distributed people engaged in all aspects of product development. In this paper, we designed a multi-user cooperative works platform, SPACE(Software Platform for distributed Application sharing under Cooperative Environment} as a infrastructure that support to CSCW based system development for telecommunication and information system. SPACE has a fully distributed architecture under Windows 95 environment, has an application sharing mechanism enabling collaborative use of mteractive application adapt to a mixed GUI sharing technology which capture GUI and screen information, and also, an event sharing technology that has a replicated architecture.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.40 no.12
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• pp.83-93
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• 2003

Differentiated service networks, based on bandwidth broker, perform the control and management of QoS provisioning for the QoS guaranteed services, However, the centralized bandwidth broker model has a scalability problem since it has centralized resource management for the admission control function of all call attempts, Therefore, in this paper, we proposea novel adaptive admission control mechanism according to the attempted call status for enhancing the scalability under the centralized bandwidth broker model in IP differentiated service networks, The proposed mechanism decouples the function of admission control from the bandwidth broker, So, the ingress edge node performs the admission control and the bandwidth broker performs the resource management and QoS provisioning, We also introduce an edge-to-edge path concepts and the ingress edge node performs the admission control under the allocated bandwidth to eachpath. The allocated bandwidth per path adaptively varies according to the status of the attempted calls, This mechanism can significantly reduce the number of communication message between the bandwidth broker and each edge node in the network and increase the bandwidth utilization via adaptable resource allocation, In this paper we study the adaptive admission control operation and show the efficient and extensive improvement through the performance evaluation.

• Journal of Digital Convergence
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• v.15 no.8
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• pp.203-212
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• 2017

The National Housing Bond Information Relay System is a representative financial information relay system in which institutions are connected with center system. A centralized structure is expensive to construct and operate center, and there is a problem that all networks are disconnected when a failure occurs in the center system. In this paper, we propose the national housing bond information relay system model based on Blockchain technology that can process information safely and efficiently. The proposed model constructs a Blockchain network so that each institution that processes the national housing bond information can transmit information safely, and each institution manages the same distributed ledge by a smart contract. The proposed model can reduce the cost because it can process complicated national housing bond transaction information without a relay center, and a network usage and disk usage decreased by 1.7% and 8.53%.