• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2002년도 ITC-CSCC -1
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• pp.443-445
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• 2002

In this paper, we present a novel efficient semaphore implementation scheme which diminishes completion time of high priority tasks and improves reliability of a system. The real-time system is constrained to complete their tasks in time. Especially, the task of a hard real-time system must meet its deadline under unfavorable conditions. In this paper, the number and sort of the locked semaphores, when an event occurred, decide whether the context switch should occur or not, so higher priority tasks diminish in their completion time. The experimental results show that the proposed method gives performance improvements in finish time of high priority tasks of about 11% over the Zuberi.

• 한국경영과학회지
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• 제22권3호
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• pp.175-190
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• 1997

Organizational change projects such as Business Process Redisign (BPR) have been perceived to incur high risk due to their high management complexity, enterprise-wide impace, and steep project cost. This research intends to reduce such risk by developing a systematic process redesign methods, called Dynamic Process Modeling (DPM) method. DPM integrates the customer-oriented business process modeling technique with computerized visual simulation technique to promote better understanding of the target process and enable performance simulation of the proposed redesign alternatives prior to actual BPR implementations. For the cusstomer-oriented process modeling, we propose Dynamic-Event Process Chain (Dynamic-EPC) extending from the conceptual customer process model, Event-Process Chain (EPC). We compare DPM with four other implementation-level process modeling methods over eight criteria and demonstrate its effectiveness by applying it to the real-world hospital BPR case.

• 한국의학물리학회:학술대회논문집
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• 한국의학물리학회 2002년도 Proceedings
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• pp.311-313
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• 2002

We are under development of a 3D PET scanner with depth of interaction (DOI) capable of high sensitivity and high resolution. In this scanner, a maximum data transfer rate of coincidence pair's event information is 10 Mcps and one event is a 64-bit data format. This maximum data transfer rate corresponds by 10 times a conventional PET scanner. A data acquisition system, which fulfills the specification of this scanner, is considered for parallel collection with banks including several coincidence units. Data transfer rate is improved by optimizing parameters of a message size, and so on.

• 한국안전학회지
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• 제15권1호
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• pp.167-175
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• 2000

Work performance and human error are complicated phenomena so that it is very difficult to grasp the true nature of them. However, Event Related Potential (ERP) may give a clue to them because human brain reflects diverse psychophysiological process. In the present study, the possibility of ERP application to the ergonomic area was evaluated in view of grasping error symptoms. For that purpose, the subjects were asked to count specific characters in a random character matrix on a computer monitor, and their ERP was compared with their performance data. Based upon the results, the amplitude of P300 was not so high as that in the case of the Odd Ball tasks, correct response corresponded with stable ERP with high P300 amplitude whereas wrong response did with unstable, fluctuating ERP with low P300 amplitude. Those results coincided with the work performance, and it was concluded that 3-wave fluorescent with illumination level of 800 lux would be recommendable for the counting task in concern. Conclusively, ERP including P300 might supply an objective clue to the problem of human errors in cognitive process.

• 복합신소재구조학회 논문집
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• 제3권4호
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• pp.10-16
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• 2012

This study presents the effectiveness of a composite structure at improving blast resistance. The proposed composite structure consists of carbon fiber reinforced polymer (CFRP) and steel layers. While CFRP layer is used for blast energy reflection due to its high strength, steel layer is used for blast energy absorption due to its high ductility. A dynamic model is used to simulate the elastoplastic behavior of the proposed composite structure subject to blast load. Considering the magnitude variations of a blast event, the probability of failure of each layer is evaluated using reliability analysis. By assigning design probability of failure of each layer in the composite structure, the thickness of layers is optimized. A case study for the design of CFRP-steel composite structure subjected to an uncertain blast event is also presented.

• 한국통신학회논문지
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• 제21권9호
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• pp.2415-2421
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• 1996

본 논문에서는 고속 통신망에서의 멀티캐스트를 위한 고속 수송 프로토콜 XTP(Xpress Transport Protocol) Rev 4.0 을 Windows NT 상에 구현하고 그 성능을 평가하였다. 프로토콜은 이벤트(Event) 구동 방식으로 설계되었으며, 성능향상을 위해 커널 내부에 네트워크 드라이버의 형태로 구현하였다. 구현된 프로토콜의 기능은 LAN 환경하에서 Windows NT 응용 프로그램들로 테스트되었으며, TCP와 성능비교를 수행하였다.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2005년도 추계학술대회 논문집
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• pp.72-76
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• 2005

This event recorder system, owing to the advancement of communication technology, is independently installed in most on-board electronics and given integrated management by on-board monitoring equipments. However, since the safety oriented equipments such as signalling devices, train protection systems, and train radios have been mounted on trains recently" the existing on-board monitoring device is no longer reliable enough for permanent preservation of data from train crashes or fires. This study has pointed out the problems mentioned above and described the designing concept of the fault recording system for high-speed trains for effective utilization of the train management program.

• International Journal of Naval Architecture and Ocean Engineering
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• 제4권3호
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• pp.211-227
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• 2012

To implement a combined discrete event and discrete time simulation such as submarine diving simulation in a distributed environment, e.g., in the High Level Architecture (HLA)/Run-Time Infrastructure (RTI), a HLA interface, which can easily connect combined models with the HLA/RTI, was developed in this study. To verify the function and performance of the HLA interface, it was applied to the submarine dive scenario in a distributed environment, and the distributed simulation shows the same results as the stand-alone simulation. Finally, by adding a visualization model to the simulation and by editing this model, we can confirm that the HLA interface can provide user-friendly functions such as adding new model and editing a model.

• 한국환경과학회지
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• 제12권9호
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• pp.977-986
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• 2003

In this study, the scenario for a numerical modeling of the fine grid scale air dispersion phenomena was proposed and an analysis of the special event which was occurred on September 3, 2002 was performed using by a coarse grid prognostic meteorological model, a fine grid diagnostic meteorological model and a fine grid air dispersion model. Based on the results, we found that the local circulations, like as land-sea breeze, should be seriously considered for evaluating the high PM10 concentration event and for making the reduction policy of the major air pollutant emissions in Ansan area.

• 천문학회보
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• 제46권2호
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• pp.67.2-67.2
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• 2021

We present preliminary results on the chemical and kinematic analysis of accreted and heated metal-rich (-1.0 < [Fe/H] < -0.3) stars in the Galactic disk. These stars are in the ranges of e > 0.7, -100 < V_𝜙 < 100 km/s, and |Z| < 3 kpc, and are presumably heated (accreted) by (from) past merger events such as Gaia Enceladus and Sausage (GSE). These stars are largely separated into two groups based on the level of [α/Fe] and radial velocity dispersion. The first group has low [α/Fe] and high radial velocity dispersion, and the second group shows high [α/Fe] and low radial velocity dispersion. We propose that the first group of stars are accreted from the GSE galaxy, whereas the second group of stars are dynamically heated by the GSE merger event.