• The Journal of Korean Institute of Communications and Information Sciences
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• 제18권1호
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• pp.57-68
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• 1993

In this paper, we describe a multiprocessor system using the HiPi bus with pended protocol and multiple cache memories, and evalute the performance of the multiprocessor system in terms of processor utilization for various cache coherence protocols. The HiPi bus is delveloped as the shared bus of TICOM II which is a main computer system to establish a nation-wide computing network in ETRI. The HiPi bus has high data transfer rate, but it doesn't allow cache-to-cache transfer. In order to evaluate the effect of cache-to-cache transfer upon the performance of system and to choose a best-performed protocol for HiPi bus, we simulate as follows: First, we analyze the performance of multiprocessor system with HiPi bus in terms of processor utilizatIOn through simulation. Each of cache coherence protocol is described by state transition diagram, and then the probability of each state is calculated by Markov steady state. The calculated probability of each state is used as input parameters of simulation, and modeling and simulation are implemented and performed by using SLAM II graphic symbols and language. Second, we propose the HiPi bus which supports cache-to-cache transfer, and analyze the performance of multiprocessor system with proposed HiPi bus in terms of processor utilization through simulation. Considered cache coherence protocols for the simulation are Write-through, Write-once, Berkely, Synapse, Illinois, Firefly, and Dragon.

• The Journal of Korean Institute of Communications and Information Sciences
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• 제18권12호
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• pp.1815-1827
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• 1993

In this paper, we evaluate the performance of a Futurebus based multiprocessor system with MESI cache coherence protocol for four bus transaction types. Graphical symbols and compiler of SLAM II are used in modeling and simulation. A steady-state probability of each state for MESI protocol is computed by a Markov chain. The probability of each state is used as an input value for a correct simulation. Processor utilization, memory utilization, bus utilization, and the waiting time for bus arbitration are measured in terms of the number of processors, the hit ratio of cache memory, the probability of internal operation, and bus bandwidth.

• The Journal of Korean Institute of Communications and Information Sciences
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• 제16권8호
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• pp.732-744
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• 1991

In this paper, performance evaluation of the common channel signalling module which performs the message transfer part function of the CCITT No.7 in TDX 1 exchange is carried out. Simulation model is developed using SLAM II network nodes according to signalling mode and transrated into SLAM II statement, . The simulation results are compared with experimental results and analyzed in order to get the maximum throughput, processing delay time, bottleneck eiement. Also, in order to get the optimized structure of the CSM, simulation is performed on the vanous case, namely, change of the number of STB, change of STG bus or B bus speed, change of CSIOB, processing speed, change of the number of transfered message per one poll.

• Proceedings of the KSRS Conference
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• 대한원격탐사학회 2006년도 Proceedings of ISRS 2006 PORSEC Volume II
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• pp.732-735
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• 2006

Downtown cities in Japan are facing sharp fall in customers and continued shut down of shops due to decrease of population, increase in family cars and flowing of customers into the suburban large-scale retail stores. Omura City in Nagasaki Prefecture, Japan is no exception to this. For the revitalization of the downtown, many actions have been taken to open the vacant shops. However, transportation problem is the most important one to be solved for the citizens including the elderly people having difficulty in movement. Accordingly, this study was aimed at the revitalization of the downtown by substantiality public transportation. We have attempted to develop routes from the view-point of convenience by using Analytic Hierarchy Process (AHP) and Geographic Information Systems (GIS). As a result of the study, we were able to select three bus transportation areas by incorporating qualitative factors into the analysis. Finally, the study concluded that, revitalization activities of the downtown city itself is required in addition to re-structuring of bus transportation system for the revitalization of the downtown city.

• Journal of the Korea Society of Computer and Information
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• 제27권9호
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• pp.217-224
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• 2022

Based on the success model and Expectation Confirmation model of information system, the concept model of mobile bus payment App users' willingness to continue using is constructed by introducing function quality and interface design quality. A total of 264 valid questionnaires are obtained by issuing online questionnaires, and the model is tested by SmartPLS3.0 software The results show that users' perceptions of information quality, system quality and interface design quality will affect users' perceived usefulness and satisfaction through the scene, and then affect users' willingness to continue to use; Perceived functional quality has a significant impact on perceived usefulness, but has no significant impact on satisfaction. Perceived usefulness has a significant impact on user satisfaction.

• International Journal of Internet, Broadcasting and Communication
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• 제9권2호
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• pp.42-47
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• 2017

In these days, the size of urban is growing and the function of city becomes complicated. And also, in city, people lives a lot. The life of urban is getting closer and linked with neighboring people in many parts. Especially, when peoples are exposing during using public transportation, even though does not be known, in they were living. Seoul is the most crowded place in Korea. In Seoul,The village buses have been serviced to the narrow streets. And people who use this bus, wants to seek the comfort of the ride, air quality and noise during in vehicle. In this paper, we determine the degree of annoyance with the noise inside the town bus in dB scale. And, such a situation was confirmed annoyance see their effect. The Interior noise did not see a big difference in the new car and the old car. Annoyance but also according to the skill of the bus driver remains the difference was confirmed.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• 제17권2호
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• pp.213-220
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• 2006

This paper investigates how the PCB power-bus sturcture's characteristics are influenced by the loading of decoupling capacitors in conjunction to other lumped elements including vias. The fields and impedance profiles are rigously evaluated and analyzed on various cases loaded with the above components and their effects will be given to bring better PCB EMC countermeasurs.

• Proceedings of the Korea Electromagnetic Engineering Society Conference
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• 한국전자파학회 2005년도 종합학술발표회 논문집 Vol.15 No.1
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• pp.149-152
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• 2005

The DC power-bus' resonance is frequently attributed to EMI sources in the PCBs. Subsequently, it will ruin the digital signal integrity within one system or between adjacent systems in the form of conducted or radiated emission. Hence, since it is of importance to examine the PCB's emission, this paper sheds a light on the radiated emission from the power-bus with regards to its resonance modes. A full-wave analysis method is used to calculate the impedance and radiated electric fields and is validated by physics and an EM analysis tool.

• Journal of electromagnetic engineering and science
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• 제5권4호
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• pp.193-196
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• 2005

The DC power-bus for the PCB is loaded with metal walls on its selected sides and is characterized electromagnetically. This is a novel concept of approach to mitigate the spurious resonance and finally signal integrity problems. In particular, the peak at DC, which is always in the way to secure parallel-plates' EMC, can be completely removed by the proposed method. Through the findings of this study, the effect of metal-loading of the power-bus will be presented along with the impression that the suggested technique can tackle the headaches of signal integrity, ground bounce, EMIs.

• Journal of Electrical Engineering and Technology
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• 제11권1호
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• pp.76-85
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• 2016

This paper presents a method of decision on where bus splitting is needed to reduce fault current level of power systems and to satisfy the fault current constraints. The method employs a modified fault current constrained optimal power flow (FCC-OPF) with X variables for the candidate locations of splitting and for decision making on whether to split or not, it adopts soft-discretization by augmenting inversed U-shaped penalty terms. Also, this paper discusses the procedure on the adequate selection of bus splitting locations based on the results of the modified FCC-OPF, to reduce the total number of the actions taken.