• Journal of Astronomy and Space Sciences
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• 제14권1호
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• pp.158-165
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• 1997

The Sun interference event predictions for the KOMPSAT TT&C station were performed to analyze the frequency of the event and the impact on the TT&C link. The KOMPSAT orbit was propagated including only J2 geopotential term for maintaining the Sun-synchronism and no other perturbations were included. Local time of ascending node of the KOMPSAT satellite was set to 10h50m00s. The TT&C station was assumed to locate in Taejon and have 9 meter antenna for S-band link. One year of simulation from 1999/07/01 were performed out of 3 year of mission lifetime of KOMPSAT satellite. Total four times of Sun interference events were occurred during 1 year of simulation and those lasted about 50 seconds altogether. The C/N degradation of the TT&C system was calculated about 4dB. The Sun interference event of 50 seconds of year are 0.0076 percents of the S-band contact time when the 30 minute of contact time is assumed in a day.

• 한국통신학회논문지
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• 제35권11A호
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• pp.1066-1072
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• 2010

본 논문에서는 다중 PTZ 카메라 기반의 다중이벤트 처리 감시시스템을 제안하였다. 각각의 PTZ 카메라에는 검출할 이벤트의 종류를 설정할 수 있다. 기존 PTZ 감시 카메라에는 하냐의 카메라가 하나의 이벤트 처리를 하기 때문에 새로운 객체가 발생하여 새로운 이벤트를 설정해야 할 경우 문제가 생기며, 각각의 PTZ 카메라는 감시하는 영역아 정해져 있기 때문에 객체가 감사할 수 없는 곳으로 이동시 추적이 불가능한 문제가 발생한다. 본 논문에서는 이러한 문제점을 해결하기 위하여 하나의 PTZ 카메라에 새로운 객체가 발생했을 때 주변의 PTZ 카메라에서 새로운 객체의 위치 좌표를 추정하여 객체를 감시할 수 있는 감시 시스템을 제안하고, PTZ 카메라의 영역에서 벗어나는 객체에 대한 이벤트 링크를 다시 설정함으로써 객체의 감시가 지속적으로 가능하게 하는 시스템을 제안하였다. 모의실험을 통해 제안 방식의 우수한 성능을 입증하였다.

• 한국컴퓨터정보학회논문지
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• 제20권8호
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• pp.35-43
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• 2015

Recently, internal information leaks is increasing rapidly by internal employees and authorized outsourcing personnel. In this paper, we propose a method to integrate internal control systems like system access control system and Digital Rights Managements and so on through expansion model of SIEM(Security Information Event Management system). this model performs a analysis step of security event link type and validation process. It develops unit scenarios to react illegal acts for personal information processing system and acts to bypass the internal security system through 5W1H view. It has a feature that derives systematic integration scenarios by integrating unit scenarios. we integrated internal control systems like access control system and Digital Rights Managements and so on through expansion model of Security Information Event Management system to defend leakage of internal information and customer information. We compared existing defense system with the case of the expansion model construction. It shows that expanding SIEM was more effectively.

• 제어로봇시스템학회논문지
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• 제2권3호
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• pp.209-219
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• 1996

Fieldbus provides a real-time data communication among field devices in the process control and manufacturing automation systems. In this paper, a Petri Net model of the 1993 draft of IEC/ISA fieldbus which is proposed as an international standard of fieldbus network is developed. Based on the Petri Net model, discrete-event simulation model of IEC/ISA fieldbus network is developed. This paper evaluates the network induced delay in the data link layer of IEC/ISA fieldbus using the simulation model. In addition, an integrated discrete-event/continuous-time simulation model of fieldbus system and distributed control system is developed. This paper investigates the real-time data processing capability of IEC/ISA fieldbus and the effect of network-induced delay to the performance of control system.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1993년도 한국자동제어학술회의논문집(국내학술편); Seoul National University, Seoul; 20-22 Oct. 1993
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• pp.348-352
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• 1993

A hybrid system contains both continuous variables and discrete event components. This paper presents the new control architecture for hybrid systems, which consists of a conventional controller for the continuous-time variable of the system, a supervisor for discrete event components of the system, and an interface for link between the controller and the plant. The presented controller is suitable for the system operating at the different operating conditions or for system being changing the plant model by enabling and disabling discrete events. This paper shows that the presented controller is better than the conventional controller.

• Geomechanics and Engineering
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• 제25권2호
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• pp.135-142
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• 2021

This study provided a new research perspective for processing and analyzing AE data to evaluate rock failure. Cluster method and information entropy theory were introduced to investigate temporal and spatial correlation of acoustic emission (AE) events during the rock failure process. Laboratory experiments of granite subjected to compression were carried out, accompanied by real-time acoustic emission monitoring. The cumulative length and dip angle curves of single links were fitted by different distribution models and distribution functions of link length and directionality were determined. Spatial scale and directionality of AE event distribution, which are characterized by two parameters, i.e., spatial correlation length and spatial correlation directionality, were studied with the normalized applied stress. The entropies of link length and link directionality were also discussed. The results show that the distribution of accumulative link length and directionality obeys Weibull distribution. Spatial correlation length shows an upward trend preceding rock failure, while there are no remarkable upward or downward trends in spatial correlation directionality. There are obvious downward trends in entropies of link length and directionality. This research could enrich mathematical methods for processing AE data and facilitate the early-warning of rock failure-related geological disasters.

• Nuclear Engineering and Technology
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• 제31권2호
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• pp.226-235
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• 1999

Applying digital network technology for advanced nuclear plant requires deterministic communication for tight safety requirements, timely and reliable data delivery for operation-critical and mission-critical characteristics of nuclear plant. Communication protocols, such as IEEE 802/4 Token Bus, IEEE 802/5 Token Ring, FDDI, and ARCnet, which have deterministic communication capability are partially applied to several nuclear power plants. Although digital communication technologies have many advantages, it is necessary to consider the noise immunity from electromagnetic interference (EMI), electrical interference, impulse noise, and heat noise before selecting specific digital network technology for nuclear plant. In this paper, we consider the token frame loss and data frame loss rate due to the link error event, frame size, and link data rate in different protocols, and evaluate the possibility of failure to meet the hard real-time requirement in nuclear plant.

• 한국통신학회논문지
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• 제41권12호
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• pp.1925-1932
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• 2016

One of the major challenges in the design of wireless sensor network (WSN) is to reduce the energy consumption of sensor nodes for prolonging the network lifetime. In the sensor network, communication is the most energy consuming event. Therefore, most of the energy saving techniques conserve energy by adjusting different parameters of the trans-receiver. Among them, one of the promising methods is the transmission power control (TPC). In this paper, we investigated the effects of the link quality based TPC scheme employed to the IEEE 802.15.4 standard for energy saving. The simulation results demonstrated that the link quality based TPC scheme works effectively in conserving energy as compared to the conventional IEEE 802.15.4.

• 기록학연구
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• 제71호
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• pp.131-167
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• 2022

이 논문은 제16대 대통령기록 중에서 기록관리비서실이 대통령 행사와 관련해서 생산한 '말씀록'의 생산 과정을 둘러싼 기록들의 내용을 분석하였다. 이를 통해 대통령기록관에 이관된 참여정부의 대통령 행사 기록의 생산 맥락을 올바로 이해한 가운데 관련 기록을 연계, 조직하여 적극적으로 활용하는 방안을 제안하였다.

• 정보처리학회논문지B
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• 제12B권1호
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• pp.81-90
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• 2005

본 논문에서는 다국어 뉴스에 대해서 '시간' 요소와 '언어 공간' 요소를 사건 어휘의 가중치 계산에 반영하는 다국어 사건 연결 탐색하는 방법을 제안한다. 시간의 흐름과 다국어 공간상에서 어휘의 분포 특성을 어휘의 가중치로 반영하여 사건 중심 어휘에 변별력을 줌으로써 같은 사건을 다루는 문서를 탐색하도록 한다. 시간상에서 어휘가중치는 전체 시간의 모든 문서집합에서의 어휘 분포와 특정 시간의 문서집합에서의 어휘 분포를 비교함으로써 계산하고, 그 특정 시간의 어휘의 가중치로 표현한다. 두 개의 언어는 하나의 언어에서보다 더 많은 정보를 줄 수 있기 때문에, 각 언어공간에서 어휘의 중요도를 측정하고, 다국어 처리에서 다른 언어 공간에서의 정보를 참조함으로써 언어 공간에서의 참조 역할을 하도록 한다. 본 논문의 실험에서는 같은 기간의 한국어와 일본어 신문기사에 대해서 사건 연결 탐색 성능을 평가하였다. 일반적인 가중치 기법인 tfidf 가중치 기법과의 비교 평가에서, 제안 방법이 단일언어 문서쌍에 대한 사건 연결 탐색은 $14.3{\%}$, 다국어 문서쌍에 대한 사건 연결 탐색에서는 $16.7{\%}$의 성능 향상을 보였다. 제안한 가중치 요소에 대한 유효성을 검증하기 위해, 공간 밀집도를 측정하였는데, 같은 사건을 나타내는 문서들의 그룹에서는 높은 밀집도를 나타냈고, 서로 다른 사건을 나타내는 문서들의 그룹에서는 낮은 밀집도를 나타냈다. 이 결과를 통해서 시간과 공간 요소를 반영한 사건 어휘 가중치 방법이 단일언어 사건 연결 탐색뿐만 아니라 다국어 사건 연결 탐색에 효과적이라고 볼 수 있다.