• 정보처리학회논문지C
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• 제14C권6호
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• pp.525-536
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• 2007

차세대 네트워크의 성공적인 추진을 위하여 트래픽 엔지니어링이 보장되는 중앙 집중형 제어 및 관리 기술이 네트워크 제어 플랫폼인 NCP(Network Control Platform)와 서비스 품질을 보장하는 스위치인 QSS(Quality of Service Switch)로 실현되고 있다. 본 논문에서는 NCP와 QSS 사이의 SNMP 인터페이스에서 고속의 연결 관리를 위하여 병렬형 기법과 쓰레드 및 객체 풀을 도입하였다. 연결 관리의 테스트-베드를 구축하여 본 논문에서 도입한 고속화 방안을 실험실 환경에서 확인하였으며, 연결 설정의 지연과 완료율을 측정하여 성능을 비교 및 분석하였다. NCP와 QSS 사이의 SNMP 인터페이스에서 연결 관리의 고속화를 위하여 병렬형 방식과 객체 풀의 사용이 중요한 성능 파라미터임을 확인하였다.

• 한국멀티미디어학회논문지
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• 제9권1호
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• pp.89-100
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• 2006

OBS 망을 위한 GSMP 개방형 인터페이스 도입은 OBS 망의 전달평면과 제어평면의 분리를 실현하여 OBS 스위치의 구현을 단순화시키고, 망의 다양한 융통성을 제공한다. 그러나 GSMP 프로토콜의 실행 오버헤드로 인하여 연결설정이 증가하는 단점이 있다. 또한 GSMP 개방형 인터페이스에서 망 관리의 위치가 제어기인지, 스위치인지 명확하게 규정되어 있지 않으며, OBS에 대한 망 관리의 연구결과는 전무한 상태이다. 본 논문에서는 GSMP 개방형 인터페이스 기반의 OBS 망에서 연결설정 지연을 최소화하기 위하여 중앙집중형 연결제어 서버를 이용한 병렬형 연결설정 메커니즘을 제안한다. 또한 GSMP 개방형 인터페이스가 적용된 OBS 망의 연결, 구성, 성능 및 장애관리를 위한 관리객체를 정의하고, 이들 관리 정보가 관리 기능별로 OBS 스위치와 제어기에 분산되어 탑재되는 분산 망 관리 모델을 제안한다. 제안한 병렬형 연결설정 메커니즘 및 분산 망 관리 모델을 이용한 망 관리 기능의 구현을 통하여 OBS 제어 및 망 관리의 실현성을 확인하였다.

• 한국도로학회논문집
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• 제15권6호
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• pp.49-60
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• 2013

PURPOSES : The evaluation of the pavement condition of the asphalt concrete pavement of No. 2 runway of Inchon International Airport through PMS, a supporting system for making a decision of pavement, maintenance and repair, was made, and the proper time for repair according to the PCI reduction rate was suggested. METHODS : By comparing and analyzing the evaluation results of pavements built in 2009, 2010, 2011, PCI change in each facility (No. 2 runway, C parallel taxiway, connection taxiway) was calculated. By applying the calculated change to PCI deduction rate model, the pavement condition of the target sections was estimated, and then the necessary section and time for repair were chosen. RESULTS : After careful consideration of the time for pavement and maintenance, based on the result of PCI prediction, it was estimated that the southern takeoff and landing section of No. 2 runway was required to be repaired in 2012; connection taxiway in 2013; and C parallel taxiway in 2014; however, the section which is the main moving route of connection taxiway and C parallel taxiway was needed to be repaired in 2012. CONCLUSIONS : For maintenance and repair of airport pavements, the optimal alternative should be chosen by considering economics and operability, via examining the time for repair and the aspect of management all together on the basis of this study.

• 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.

• 한국태양에너지학회:학술대회논문집
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• 한국태양에너지학회 2008년도 춘계학술발표대회 논문집
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• pp.43-48
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• 2008

Through simulations and field experiment on A.C. parallel operation of both Utility Interactive Photovoltaic System and Diesel Engine Revolving Field Type Synchronous Generator, following factors have been found. First, the inverter should be operated in three modes of frequency(mode.1: ${\pm}$0.3Hz, mode.2: ${\pm}$1Hz, mode.3: ${\pm}$2Hz) as default, considering properties of operating Synchronous Generator. Second, as a result of supplying 13.5kW of residual power, it has been found that Synchronous Generator takes the power input only as reactive power, because it was electrically stable with frequency of 60.14Hz and high voltage of 222.3V even when power factor was -0.94. Besides, it was mechanically stable, too, because the quake, noise, and temperature of Synchronous Generator in this case were 7.5mm/s, 97dB, and $6^{\circ}C$ respectively, which were lower than normal load connection of 145.6kW; 11.03mm/s. Thus, load share of Revolving Field Type Synchronous Generator reduces according to the supply of Photovoltaic System to the load power. In this experiment, 200kW of Synchronous Generator and 40kW of Photovoltaic System were operated in parallel. The load share was 20% in maximum. and 11.1lit/hr of fuel was saved.

• 한국전기전자재료학회논문지
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• 제25권9호
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• pp.723-726
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• 2012

A current intensity convertible CLD chip was fabricated using small and large FET cell configuration. Pinch-off current of 8.82 mA and 11.56 mA were obtained for small and large cell in the CLD chip, respectively. Constant current was fairly maintained until the breakdown voltage of 60 V. Measured knee voltage, $V_k$ were 3.8 V and 4.5 V for small and large cell, respectively. We configured current amplifying chip with parallel connection of each cells, by connecting 8 individual large cells in parallel network, 92.0 mA of current was obtained. The pinch-off constant current of CLD chip was varied very linearly with respect to the number of parallel connected cell.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2001년도 추계학술대회 논문집 전기기기 및 에너지변환시스템부문
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• pp.245-248
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• 2001

Recently, with the advancement of internet network the system has been needed to be controllable and observable through internet at industrial workplace. In this study, we developed the digital timer which has a communication function to control and observe many kinds of devices by combining relay and timer used for each type of control panel to realize control solution based on internet to be easily applicable at workplace with low cost and adding 485 serial communication module to have parallel expansibility and safety. And, this system was experimented and designed for easy system management and status check from remote station through internet. appling the developed digital timer to parallel sequence control of motor. As the result of experiment, the circuit configuration would be more simplified than the existing, and it is expected that multi-connection control and monitoring can be simply implemented with low cost equipment at industrial workplace.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2001년도 추계학술대회 논문집 전기기기 및 에너지변환시스템부문
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• pp.157-160
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• 2001

Recently, with the advancement of internet network the system has been needed to be controllable and observable through internet at industrial workplace. In this study, we developed the digital timer which has a communication function to control and observe many kinds of devices by combining relay and timer used for each type of control panel to realize control solution based on internet to be easily applicable at workplace with low cost and adding 485 serial communication module to have parallel expansibility and safety. And, this system was experimented and designed for easy system management and status check from remote station through internet, appling the developed digital timer to parallel sequence control of motor. As the result of experiment, the circuit configuration would be more simplified than the existing, and it is expected that multi-connection control and monitoring can be simply implemented with low cost equipment at industrial workplace.

• 한국경영과학회지
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• 제40권1호
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• pp.185-198
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• 2015

This study drew performance management factors analyzed a causal link between acceptance and satisfaction of performance management to present the method for promoting acceptance on the performance management system that most of the public enterprises, government-affiliated organizations are implementing. To achieve this, qualitative analysis and quantitative analysis were conducted in parallel through in-depth case studies and surveys. The results of this study are as follows. First, the analysis of the performance management factors with preceding studies shows that performance management indicators, performance management operations and performance management communications. Second, from the causal relationship of performance management factors affecting performance management acceptance reveals that performance management operation has statistical significance. Third, the analysis of the effect of performance management factors on the management satisfaction shows that operation and indicator of the performance management have statistical significance and reflecting the performance indicators to business, adequacy of target level, training, system support and CEO's Leadership have been revealed as important variables to the management satisfaction. Fourth, the result of the analysis on casual connection between acceptance and satisfaction of the performance management shows that improving management acceptance has a direct impact on satisfaction because performance management receptiveness were deemed statistically significant. Fifth, the result of the in-depth case studies on improving performance management acceptance shows that public enterprises have been putting in an effort to design indicators and try to encourage internal member's involvement during the monitoring and evaluation. The quantitative analysis based on survey has turned out that performance management operation and performance management indicators have statistical significance. The qualitative analysis by in-depth analysis shows that public enterprises put a lot of effort to performance management indicators and communication between internal members. As a result, commitment to performance management operation is required to improve the performance management acceptance. In other words, a detailed implementation plan for training, information system support, and CEO's leadership has to be established and ought to be pushed.

• 대한전기학회논문지:시스템및제어부문D
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• 제51권7호
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• pp.279-285
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• 2002

This Paper deals with the economical equipment control which is used by internet network system at the industrial workplace. If the control devices can be accessed by internet, we can have the developed possibility of work conditions. in this paper, we presented the advanced digital timer which has a communication function to control and observe panel to realize control solution based on internet to be easily applicable at workplace with low cost, and we used RS-485 serial communication module to have parallel expansibility and safety. And, this system was experimented and designed for easy system management and status check from remote station through internet. As the result for experiment, the circuit configuration would be more simplified than the existing, and it is expected that multi connection control and monitoring can be simply implemented with low cost equipment at industrial workplace.