• 전기전자학회논문지
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• 제8권2호
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• pp.207-215
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• 2004

계층버스 다중처리기 시스템에서 캐시 일관성 프로토콜은 시스템 성능에 영향을 준다. 특정 캐시 일관성 프로토콜 하에서 시스템의 성능은 버스의 대역폭 및 메모리크기, 메모리 블록의 크기에 따라 영향을 받는다. 따라서 시스템 성능에 영향을 미치는 요소들에 대한 민감도 분석이 필요하다. 본 논문에서는 계층버스 다중처리기에 캐시 일관성 프로토콜을 적용하고, 프로토콜에서 정의된 상태가 나타날 확률을 구하였다. 구해진 확률값을 분석적 모델에 적용하여 시뮬레이션을 하였다. 그리고 시뮬레이션 결과를 기반으로 시스템의 성능에 영향을 미치는 요소에 대한 민감도 분석을 하였다.

• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 2005년도 Proceedings of ISRS 2005
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• pp.493-496
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• 2005

The PMU (Payload Management Unit) in MSC (Multi-Spectral Camera) is the main subsystem for the management, control and power supply of the MSC payload operation. The PMU shall handle the communication with the BUS (Spacecraft) OBC (On Board Computer) for the command, the telemetry and the communications with the various MSC units. The PMU will perform that distributes power to the various MSC units, collects the telemetry reports from MSC units, performs thermal control of the EOS (Electro-Optical Subsystem), performs the NUC (Non-Uniformity Correction) function of the raw imagery data, and rearranges the pixel data and output it to the DCSU (Data Compression and Storage Unit). The BUS provides high voltage to the MSC. The PMU is connected to primary and redundant BUS power and distributes the high unregulated primary voltages for all MSC sub-units. The PSM (Power Supply Module) is an assembly in the PMU implements the interface between several channels on the input. The bus switches are used to prevent a single point system failure. Such a failure could need the PSS (Power Supply System) requirement to combine the two PSM boards' bus outputs in a wired-OR configuration. In such a configuration if one of the boards' output gets shorted to ground then the entire bus could fail thereby causing the entire MSC to fail. To prevent such a short from pulling down the system, the switch could be opened and disconnect the short from the bus. This switch operation is controlled by the BUS.

• 한국정보통신학회:학술대회논문집
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• 한국정보통신학회 2021년도 추계학술대회
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• pp.388-390
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• 2021

본 논문은 키패드, 도트매트릭스, 라이다센서, NFC 리더기를 부착한 임베디드 보드와 공공데이터포털 Open API 시스템과 딥러닝 알고리즘(YOLOv5)를 사용하여 시각장애인의 버스 탑승에 도움을 줄 수 있는 시스템을 소개한다. 이용자는 NFC 리더기 및 키패드를 통해 희망하는 버스번호를 입력한 뒤, Open API 실시간 데이터를 통해 해당 버스의 위치 및 도착예정시간 정보를 시스템에 입력해놓은 음성 출력을 통해 얻는다. 또한 도트매트릭스로 버스번호를 출력하여 기사와의 상호작용을 대기함과 동시에 딥러닝 알고리즘(YOLOv5)은 정차하는 버스 번호를 실시간 인식하고 거리센서로 버스와의 거리를 감지하여 정차유무정보를 확인, 전달하는 시스템을 제안한다.

• 한국도로학회논문집
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• 제18권5호
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• pp.105-115
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• 2016

PURPOSES : This study was initiated to analyze the characteristics of bus traffic accidents, by bus types, using the decision tree in order to establish customized safety alternatives by bus types, including the intra-city bus, rural area bus, and inter-city bus. METHODS : In this study, the major elements involved in bus traffic accidents were identified using decision trees and CHAID algorithm. The decision tree was used to identify the characteristics of major elements influencing bus traffic accidents. In addition, the CHAID algorithm was applied to branch the decision trees. RESULTS : The number of casualties and severe injuries are high in bus accidents involving pedestrians, bicycles, motorcycles, etc. In the case of light injury caused by bus accidents, different results are found. In the case of intra-city bus accidents, the probability of light injury is of 77.2% when boarding a non-owned car and breaching of duty to drive safely are involved. In the case of rural area bus accidents, the elements showing the highest probability of light injury are boarding an owned car, vehicle-to-vehicle accidents, and breaching of duty to drive safely. In the case of intra-city bus accidents, boarding owned car, streets, and vehicle-to-vehicle accidents work as the critical elements. CONCLUSIONS : In this study, the bus accident data were categorized by bus types, and then the influential elements were identified using decision trees. As a result, the characteristics of bus accidents were found to be different depending on bus types. The findings in this study are expected to be utilized in establishing effective alternatives to reduce bus accidents.

• 한국ITS학회 논문지
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• 제7권2호
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• pp.1-12
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• 2008

최근 극심함 교통혼잡 및 유류비 상승으로 인해 대중교통(특히 버스)의 역할이 더욱 크게 부각되고 있으나, 일부 황금노선을 제외한 대부분의 버스노선이 지속적인 이용수요감소, 수입감소, 경영수지악화, 서비스질 저하, 이용자감소의 악순환을 끊기 위해 버스의 공공성 강화의 한 방편인 준공영제(관리는 공공, 운영은 민영)를 도입하였으나, 당초 민간의 효율성을 제고하고자 했던 의도와는 다르게 운수회사의 자발적인 운행관리가 이루어지지 않는 등 부작용을 해결하기 위한 공공부분의 운행관리가 매우 중요한 요소가 되었다. 본 연구에서는 준공영제 하에서, APTS 자료를 활용하여 민간 운수회사의 평가관리가 가능하고, 시민이 피부로 느낄 수 있는 버스신뢰성 제고를 위해 서울시에서 관리중인 운행관리항목의 종류와 분석방법론, 운행관리결과, 문제점 및 향후 대책에 대하여 고찰하였으며, 이러한 연구내용이 이미 준공영제를 도입하였거나, 도입을 준비하고 있는 타 시도의 운행관리정책에 기여할 수 있을 것이다.

• 전기학회논문지P
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• 제58권4호
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• pp.404-409
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• 2009

A DC power system has many loads with various functions. In particular, these sizable loads take the form of power electronic converters. When they are tightly regulated, the loads appear as constant power loads and result in negative incremental input impedance. Under certain conditions the effect of such loads on the power system is causes instability. In this paper, converter with a large storage capacitor and a lag compensator is proposed as a DC bus conditioner to mitigate the voltage transients on the bus. In addition, the proposed control approach has the advantage of performing both the functions of mitigating the voltage bus transients and maintaining the level of energy stored. Simulation and experimental results showed that the proposed control method was operated well in a small-scale DC power system that contained subsystems with constant power characteristics, such as DC/DC converters and electrical drives.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1987년도 한국자동제어학술회의논문집(한일합동학술편); 한국과학기술대학, 충남; 16-17 Oct. 1987
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• pp.863-869
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• 1987

INFOBUS, which has been designed as a system bus of a multiprocessor system, will be introduced. And the concepts of the multiple transfer and ORed write transfer will be described. These concepts make INFOBUS to be well suited for use as the system bus of the multiprocessor based programmable controller(MBPC). In addition, the mean data transfer time through INFOBUS, which is one of the most significant performance of a bus, will be obtained by analysis and simulation. Next, MBPC which uses INFOBUS as its system bus will be introduced, and some basic characteristics of MBPC will be described. The construction of exact model for MBPC will be given and simulated using SDL/SIM package. The reference system of our model will be briefly described also. Some results from the simulation will be given and validated.

• Journal of Electrical Engineering and Technology
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• 제8권4호
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• pp.694-703
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• 2013

In electric power system, the line stability indices adopted in most of the instances laid stress on variation of reactive power than real power variation of the transmission line. In this paper, a proposal is made with the formulation of a New Voltage Stability Index (NVSI) which originates from the equation of a two bus network, neglecting the resistance of transmission line, resulting in appreciable variations in both real and reactive loading. The efficacy of the index and fuzzy based load flow are validated with IEEE 30 bus and Tamil Nadu Electricity Board (TNEB) 69 bus system, a practical system in India. The results could prove that the identification of weak bus and critical line in both systems is effectively done. The weak area of the practical system and the contingency ranking with overloading either line or generator outages are found by conducting contingency analysis using NVSI.

• Journal of Electrical Engineering and Technology
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• 제8권6호
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• pp.1305-1309
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• 2013

The application of the superconducting fault current limiter (SFCL) in a power distribution system is expected to contribute the voltage-sag suppression of the bus line as well as the fault-current reduction of the fault line. However, the application effects of the SFCL on the voltage sag of the bus line including the fault current are dependent on its application location in a power distribution system. In this paper, we investigated the fault current limiting and the voltage sag suppressing characteristics of the SFCL due to its application location such as the outgoing point of the feeder, the bus line, the neutral line and the 2nd side of the main transformer in a power distribution system, and analyzed the trace variations of the bus-voltage and fault-feeder current. The simulated power distribution system, which was composed of the universal power source, two transformers with the parallel connection and the impedance load banks connected with the 2nd side of the transformer through the power transmission lines, was constructed and the short-circuit tests for the constructed system were carried out. Through the analysis on the short-circuit tests for the simulated power distribution system with the SFCLs applied into its representative locations, the effects from the SFCL's application on the power distribution system were discussed from the viewpoints of both the suppression of the bus-voltage sag and the reduction of the fault current.

• 한국정보과학회논문지:시스템및이론
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• 제32권6호
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• pp.324-332
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• 2005

일반적으로 버스에서 소모되는 에너지는 전체 시스템에서 큰 비중을 차지한다. 버스 분할 방법은 시스템의 소모 에너지를 줄이고 각 버스 세그먼트들의 기생 부하(parasitic load)를 감소시킴으로서 지연시간을 줄이는데 사용될 수 있다. 버스를 분할함에 있어서 버스에 의해 상호 연결된 처리소자들 사이의 데이타 교환 확률 분포에 따라 가장 적은 에너지를 소모하는 버스 분할 방법은 달라질 수 있다. 본 연구에서는 수평적인 버스 분할 구조의 확장된 개념으로 트리구조 기반의 버스 분할 방법에 대해 연구하고, 이를 바탕으로 여러 가지 버스 분할 방법 중에서 주어진 시스템의 처리소자 간 데이타 교환 확률의 분포에 따라 가장 적합한 구조를 선택하는 문제에 대해 논하였다. 실험 결과는 제안된 방법들이 버스에서 소모되는 에너지를 최대 83$\%$까지 감소시킬 수 있음을 보여준다.