• 한국통신학회논문지
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• 제25권3A호
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• pp.443-450
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• 2000

Although designing a virtual topology for all-optical WDM wide-area networks has been extensively studied and several algorithms have been proposed, these algorithms assumed error-free communication between two nodes. However, noises from optical amplifiers and optical cross-connects can degraded the signal, resulting in a nonzero bit-error rate. In this paper, we investigate the effect of physical limitations on the virtual topology design. We show that for side-area all-optical networks where transmission distance is fairly long, virtual topology design algorithm that can determine the locations of opto-electronic(OE) and electro-optic(EO) conversions to set up a connection request with a high BER in a multihop manner.

• 한국태양에너지학회 논문집
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• 제26권2호
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• pp.61-67
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• 2006

The use of the wind energy resource is a rapidly growing area world-wide. The number of installed units is continuously increasing, and therefore, it is important to respect and to deal with the impact of wind power generation system. From the view of an electric grid utility, there is a major problem with the impact of the wind system on the voltage of the electric grid, to which a turbine is connected. In this paper, it is investigated the voltage impact and transient state analysis on distribution line, with which wind power generation system is connected. Connections of wind power system usually occur to voltage drop due to reactive power absorption and sometime result in higher than nominal voltage.

• 한국CDE학회논문집
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• 제13권4호
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• pp.305-313
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• 2008

A configuration management system was implemented by applying PLM to the defense field. The PLM system has recently been incorporated in a wide range of industries, and it has allowed for improvements in work productivity and expansion of related services by comprehensively managing and securing connection regarding configuration information in the defense field. Implementations include acquisition of configuration related information and reinforcement of BOM-oriented configuration management function, securing compatibility among 3D drawings of different agencies, improvement of drawing and document management functions, comprehensive systematic configuration management focused on product structure, strengthened configuration control functions, a management system according to the work flow and life cycle functions, an integrated configuration management system of 3D model CAD resources and an enhanced management system. This paper covers a case study reviewing the implementation of a PLM-based configuration management information system and its results, so that the information can be made available to other agencies and companies seeking to apply PLM in their organizations.

• 디지털융복합연구
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• 제4권1호
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• pp.31-41
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• 2006

This article introduces developing trends of an 'Ubiquitous Interface' as an access method for use of various network resources, such as public wireless networks and un-licensed wireless networks in ubiquitous sensor network environments, without troublesome settings or operations by users. 'Ubiquitous Interface' is a relatively wide sense meaning not only physical interface of specified device or between processors, but anything method for access USN. These 'Ubiquitous Interface' able to provide seamless services that adapt autonomously to the user's movements and changes in the state of wireless resources. Recently, strongly recommended current technologies are RFID, NFC, Multi-mode mobile terminal, UMA mobile terminal and Wearable computer as a future ubiquitous interface. These technologies are have to have flexibility and multiple physical communication channels for seamless service hand over and serve easy connection at huge USN to user. Also, they have to must have flexible software structure. Finally, through the 'Ubiquitous Interface', we will be experience of seamless communication and realize a real liberty of communication.

• 환경위생공학
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• 제10권3호
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• pp.115-123
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• 1995

Most countries have problems regarding the quantity and quality of their fresh water resources, and many countries are suffering from the e(feces of pollution of their inland and coastal waters. Italy is one of the country in which water supply is extremely uneven, and there are wide areas where it represents a real emergencies during periods of drought. All the watershed's water resources, however, are subjected to considerable anthropogenic pressure such as organic load with heavy metals. The high values of organic materials are accounted for mainly by runoff and percolation waste water from urban and agricultural land extensively ma- nured with effluents (rom livestock farming, while high concentration of heavy metals are found in watersheds of national and interregional significance. More than 35% of the underground water bearing strata of certain basins are already contaminated by pollution boih industrial and agricultural pollutants. In these connection, the problems and new measures of water resources in Italy are overviewed.

• 한국게임학회 논문지
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• 제5권1호
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• pp.41-44
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• 2005

본 논문에서는 인터넷환경에서 증가하는 인터넷게임의 바이러스/웜의 공격에 의한 침해사고 발생시 정의되어야 할 정보와 이를 활용한 대량 트래픽을 발생시키는 탐지하는 방안을 제안하였다. 이에 따라 인터넷 게임 사고대응시스템에서의 자동화된 역추적 방안에 대한 설계와 기능에 대한 개념을 제시한다.

• 대한안전경영과학회지
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• 제2권4호
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• pp.165-176
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• 2000

Broadband networks are designed to support a wide variety of services with different traffic characteristics and demands for Quality of Services. Bandwidth allocation methods can be classified into two major categories： static and dynamic. In static allocation, bandwidth is allocated only at call setup time and the allocated bandwidth is maintained during a session. In dynamic allocation, the allocated bandwidth is negotiated during a session. The purpose of this paper is to develop policies for deciding and for adjusting the amount of bandwidth requested for a best effort connection over such as ATM networks.. This method is to develop such policies that a good trade off between utilization and latency using cell delay variation to the forecast the incoming traffic in the next period. The performances of the different polices are compared by simulations.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2007년도 춘계학술대회A
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• pp.741-745
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• 2007

Supplying power to microsystems that have no physical connection to the outside is difficult, and using batteries is not always appropriate. This paper discusses how to generate electricity from mechanical energy when vibrated in a cantilever beam. A model for the system predicts that the output power of the system is maximized when the mechanical damping in the system is minimized. Furthermore, to cover a wide frequency range and to be useful in a number of applications, a system of beams with different resonant frequencies has been designed and optimized. This information makes it possible to determine what design alternatives are feasible for the creation of a micro power supply for any specific application of MEMS.

• 한국경영과학회:학술대회논문집
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• 대한산업공학회/한국경영과학회 2000년도 춘계공동학술대회 논문집
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• pp.766-769
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• 2000

In recent years, Internet/Intranet represents the next generation of computing environment. Therefore, it is necessary to integrate WWW((World Wide Web) over internet/intranet and DBMS(Database Management System) in proportion to the increase of various users' request and an amount of data variety. Also, also full variety of service over WWW need to accomplish rapidly modification of bug and make a betterment of system according to a feature of rapid change of information and an importance of interaction with users. The typical CGI method commonly used to connect with database has a disadvantage in time and resources in system due to frequent connection with database. Therefore, this paper provides the conceptual structure and implementation of information management system over WWW with applying a recent information technology called ASP(Active Server Pages) that controls and arranges client logic dynamically in server-side and introducing a concept of working group and folder to database design.

• 기술사
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• 제29권3호
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• pp.94-104
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• 1996

When Broadband Integrated Services Digital Network(BISDN) becomes commercially available In public network, conventional Local Area Network(LAN)s will still be in use. The first wide spread application for B-ISDN will be the interconnection of LANs. The equipment providing the connection between the LAN and the BISDN will be given the general name Inter Working Unit(IWU). We addresses the congestion problem of many interworking issues. In this paper, Our study is concentrated on applying connectionless network protocol for interworking. We suggest a rate control method in the network layer to prevent a buffer overflow in the IWU. Since this rate control method can be applied to prevent buffer overflow in a congested IWU, We investigate the use of rate control to solve congestion problems of IWU and parallize network layer with rate control to lessen the congestion problem in IWU.