• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.2 no.1 s.2
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• pp.53-62
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• 2003

This paper demonstrates the in-vehicle dilemma zone warning system (DZWS) project developed as a part of the Driver Advisory and Collision Warning System in Automated Vehicle and Highway System (AVHS). The DZWS project, one of the Korea national ITS projects in 2000 develops the in-vehicle warning device to support drivers' decision making on whether to stop or to proceed to clear the intersection prior to the onset of yellow signal for avoiding the high risk of collision at signalized intersections through the dedicated short range communication (DSRC). This paper explores the design of optimal communication systems between roadway and vehicles, the operational and functional concepts of dilemma zone warning system based on appropriate approach speeds, and the system integration for field test at two sites of signalized intersections. Findings from the system integration indicated that the system would be implemented in eliminating the dilemma zone relative to approach speeds and in reducing red light violations and intersection collisions through the in-vehicle warning device at signalized intersection.

• Journal of Korean Society of Transportation
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• v.28 no.4
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• pp.167-175
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• 2010

The ubiquitous transportation system environments make it possible to collect each vehicle's position and velocity data and to perform more sophisticated traffic flow management at the individual vehicle or platoon level through vehicle to vehicle (V2V) and vehicle to infrastructure (V2I) communication. It is necessary to develop a traffic flow management scheme to take advantage of the ubiquitous transportation system environments. This paper proposes an algorithm to advise the optimal speed for each vehicle according to the traffic flow condition. The algorithm aims to stabilize the traffic flow by advising the equilibrium speed to the vehicles speeding or crawling under freely flowing condition. And it aims to prevent or at least alleviate the shockwave propagation by advising the optimal speed that should dampen the speed drop under critical flow conditions. This paper builds a simulation testbed and performs some simulation experiments for the proposed algorithm. The proposed algorithm shows the expected results in terms of travel time reduction and congestion alleviation.

• Journal of the military operations research society of Korea
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• v.34 no.3
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• pp.1-12
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• 2008

Design of supply chain network (SCN) is required to optimize every factor in SCN and to provide a long-term and strategic decision-making. A mathematical model can not reflect the real world because design of SCN contains variables and stochastic factors according to status of its system. This paper presents the designing methodology of military SCN using the mathematical model and the simulation model. It constructs SCN to minimize its total costs using the Mixed Integer Programming (MIP) model. And we solve problems of a vehicle assignment and routing through adaptation of experiment parameters repeatedly in the simulation model based on the results from the MIP model. We implement each model with CPLEX and AutoMod, and experiment to reconstruct SCN when the Logistic Support Unit is restricted to support military units. The results from these experiments show that the proposed method can be used for a design of military SCN.

• Korean Journal of Optics and Photonics
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• v.8 no.2
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• pp.81-87
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• 1997

This paper presents the optimum initial design containing the first and third order properties of the four-group video camera zoom system using lens modules, and its real lens design. The optimum initial design with focal length range of 6.1693 to 58.4065 mm is derived by assigning appropriate first order quantities and third order aberrations to each module along with the specific constraints required for optimization. By scaling the focal length of each lens group, an initial real lens selected for each group has been designed to match its focal length into that of the each lens module, and then combined to establish an actual zoom system by adjusting the air space between the groups at all zoom positions. The combination of the separately designed groups results in a system which satisfies the first order properties of the zoom system consisting of original lens modules. As a result, by residual aberration correction, we could obtain a zoom system useful in video zoom camera employing the rear focus method.

• The Journal of the Korea institute of electronic communication sciences
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• v.15 no.3
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• pp.413-420
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• 2020

The Tactical Information and Communication Network system provides real-time multimedia services such as voice and data by utilizing the Mobile Subscriber Access Point. At this time, an external transmission path is constructed through the Low Capacity Trunk Radio and the High Capacity Trunk Radio system. The communication devices of each wireless transmission system are mounted on a tactical vehicle and a secondary battery is used to prevent a power interruption when the supply power to the tactical vehicle is transferred to the integrated power control device. In this paper, the basic design of the Wireless Power Transfer device for charging the battery of the integrated power control system of the mobile base station system using the Loading Distribution Method and checking the number of primary windings and the core material selection by the air gap through the Finite Elements Method.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.36 no.12B
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• pp.1736-1743
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• 2011

In Network Centric Warfare (NCW) environment, having a tactical communication network which provides high data exchange rate is very important. In the process, Korean Army developed Mobile Subscriber Access Point (MSAP) which is based on the commercial Wireless BroadBand (Wibro). MSAP is a vehicle attached base station which provide high data exchange communication environment in a given area. Thus MSAP can provide high data exchange rate and mobility to accomplish missions in the battlefield more effectively. In this paper, we propose an operational strategy of using MSAP to provide tactical communication network in the battlefield. The idea is to find the optimal location point of the MSAP in the operational area where all the troops in the operational area can be supported by the MSAP with a minimum number of MSAP. Since the current Korean Army's basic idea of using MSAP is just distribute this MSAP to each troop, so by applying our strategy we can save MSAP devices for more flexible operation. We will show our strategy's benefits through the mathematical model and the algorithm of the presented problem.

• Proceedings of the KSR Conference
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• 2007.11a
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• pp.517-528
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• 2007

Domestic or international existing researches regarding rail damage factors are focused on laying, vehicle conditions, driving speed and driving habits and overlook characteristics of track structure (elasticity, maintenance etc). Also in ballast track, as there is no special lateral spring stiffness of track also called as ballast lateral resistance in concrete track, generally, existing study shows concrete track has 2 time shorter life cycle for rail replacement than ballast track due to abrasion. As a result of domestic concrete track design and operation performance review, concrete track elasticity is lower than track elasticity of ballast track resulting higher damage on rail and tracks. Generally, concrete track has advantage in track elasticity adjustment than ballast track and in case of Europe, in concrete track design, it is recommended to have same or higher performance range of vertical elastic stiffness of ballast track but domestically or internationally review on lateral spring stiffness of track is very minimal. Therefore, through analysis of service line track on site measurement and analysis on performance of maintenance, in this research, dynamic characteristic behaviors of commonly used ballast and concrete track are studied to infer elasticity of service line track and experimentally prove effects of track lateral spring stiffness that influence curved rail damage as well as correlation between track elasticity by track system and rail damage to propose importance of appropriate elastic stiffness level for concrete and ballast track.

• Korean Journal of Occupational Health Nursing
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• v.2
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• pp.26-39
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• 1992

본 연구는 보건관리대행기관에 근무하는 산업간호사들의 보건관리업무실태 및 근무만족도와 이들간의 관계를 파악함으로써, 산업간호업무향상 및 효율적인 산업보건관리를 위한 기초자료로 제시하고자 시도되었다. 조사대상은 38개 보건관리대행기관중 24개 기관에 근무하는 산업간호사 118명중 97명을 대상으로 하였다. 연구기간은 '92년 5월부터 6월까지 설문조사를 실시하였으며 그중 89명이 설문에 응답하여 이를 분석 대상으로 하였다. 연구결과는 다음과 같다. 첫째, 보건관리대행기관의 간호사는 산업간호사의 일반적 특성과 비교해볼 때 기존 산업간호사와 유사하였다. 그러나 법정휴가를 받는다는 간호사가 59.1%로 더 낮았다. 둘째, 보건관리대행기관 산업간호사의 담당사업장수는 법적으로 30개 사업장, 2,000명의 근로자를 담당하도록 되어있는데 조사결과 법적기준인 보건관리사업장의 수를 담당하는 간호사는 57.1%를 차지하였고, 담당 근로자 수로 볼때는 2,000명이하가 29.8%를 차지하여 많은 산업간호사가 법적인 기준을 초과하여 산업보건관리를 대행하고 있는 것으로 나타났다. 셋째, 보건관리대행의 방문방법으로 교통편은 대행 기관차량을 이용하며, 간호사 혼자 산업장을 방문하는 것이 대부분으로 나타났고, 방문횟수는 100인미만이 월1회, 100인이상이 월2회로 규정된 것과 비교해보면 규정을 따르는 곳이 100인 미만의 경우 97.4%, 100인이상의 경우 86.4%였다. 또한 의사나 위생사는 방문을 안하거나 년1-5회 방문하는 것으로 나타나 보건관리대행의 주제공자는 간호사인 것으로 냐타났다. 또한 사업장 방문시 업무수행장소는 휴게실이나 사무실이 87.5%, 현장이나 수위실에서 하는 곳이 70.5%나 되어 뚜렷이 업무를 수행할 장소가 마련되지 않은 실정을 나타냈다. 네째, 보건관리대행에 근무하는 산업간호사의 애로사항은 사업장내에서는 조직과 체계상의 문제, 간호사 역할에 대한 인식부족, 권한과 자율성 부족 등을 들었고, 사업장 방문시에는 사업주와 근로자의 인식부족이 우선적으로 지적되었다. 또한 산업간호사는 보건관리 대행업무에서 사업장의 참여유도, 사업장 순회점검 및 개선지도, 보건교육, 건강상담이 우선적으로 실시되어야 한다고 하였다. 다섯째, 보건관리대행기관 산업간호사의 업무수행정도는 건강검진이나 직업병관리, 보건교육, 환경위생관리업무를 비교적 많이 실시하는 것으로 나타났다. 여섯째, 보건관리대행기관 산업간호사의 직무만족도는 전문적 위치나 상호작용, 업무요구등은 높게 나타났으나 보수와 산업보건관계자와의 관계등은 만족도가 낮게 나타났다. 또한 직무만족도에 대한 총화점수는 사업장근무자가 240점중 143.8인데 비해 보건관리대행기관 근무자는 230점중 129.61점으로 더 낮게 나타났다. 일곱째, 일반적 특성별 보건관리대행 산업간호사의 직무수행정도는 연령별 30세이상군이, 결혼상태별로 기혼군이, 경력은 1년이상인 군이, 근무시간 8시간인군이, 급여수준은 50만원이상인군이, 법정휴가가 있는 군이, 자질향상교육을 받은군이 담당사업장수가 30개이하인 군이, 더 높게 나타났다. 또한 연령군이 20-24군과 30세이상인군 (p<0.05), 결혼상태별로 기혼군과 미혼군(p<0.01), 급여수준별로 50만원미만군과 이상인 군(p<0.05), 법정휴가가 있는 군과 없는군(p<0.05), 자질향상 교육을 받은군과 받지못한 군(p<0.01), 담당사업장수가 30이하인 군과 31인이상인 군(p<0.05) 간에 유의한 차이를 보였다. 즉 산업간호사중 나이가 많고, 기혼이며 급여수준이 높고 법정휴가와 교육을 받고, 담당사업장수가 30이하인 군이 보건관리대행업무를 잘 수행하는 것으로 나타났다. 여덟째, 일반적 특성별 보건관리대행 산업간호사의 직무만족도는 연령별 30세이상군이, 결혼상태별로 기혼군이 경력은 1년이상인 군이, 근무시간 8시간인군이, 급여수준은 50만원이상군이, 법정휴가가있는군이, 자질향상교육을 받은군이, 담당사업장수가 30개이하인 군이 더 높게 나타났다. 또한 결혼상태별로 기혼군과 미혼군(p<0.01), 근무시간별로 8시간군과 9시간 이상인 군(p<0.01), 급여수준별 50만원 미만군과 이상군(p<0.05), 자질향상교육을 받은군과 받지 않은군(p<0.05) 사이에 유의한 차이를 보였다. 즉 산업간호사중 기혼이고 근무시간은 8시간이며 급여수준이 높고 자질향상교육을 받은 군이 만족도가 높은 것으로 나타났다. 아홉째, 보건관리대행기관 산업간호사의 업무수행정도와 직무만족도 사이의 상관관계를 보면 보수, 자율성, 업무요구가 높을수록 산업간호업무를 수행을 잘하는 것으로 나타났으며(상관관계 r>0.6, P>0.001), 전체적으로 총직무만족도와 업무수행정도와의 상관관계는 6346, P<0.001로서 만족도가 높을수록 업무수행정도가 높은 것으로 나타났다. 이상의 결과를 토대로하여 보면, 보건관리대행기관에 근무하는 산업간호사는 그 특성을 고려하여 업무도 사업장 근무자와 다르게 규정되어야 하며, 담당업무의 명확한 한계를 정해 중소규모사업장의 산업보건관리업무를 책임있게 수행할 수 있도록 뒷받침이 필요하다. 더불어, 직무만족도를 높일수 있도록, 산업간호사에 대한 다방면의 지원이 필요하다고 하겠다. 또한 보건관리대행기관 산업간호사는 나이가 많고 기혼이며 경력있는 간호사를 채용하고 근로조건을 잘 개선하면 직무수행정도가 더 높아질 것으로 보인다. 좋은 근로조건의 형성과 직무만족도 등을 높여 산업간호사의 직무를 효율적으로 수행할 수 있도록 하기 위하여는 보건관리대행기관에 관한 규정이 강화 보완되어야 하겠으며, 민간단체와 의료기관 뿐아니라 공공기관에서도 중소규모사업장의 보건관리업무를 담당하는 방향으로 전환하는 방안을 모색해 보아야 할 것이다.

• Journal of Korean Society of Transportation
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• v.17 no.2
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• pp.83-90
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• 1999

A computer algorithm is presented that evaluate the performance of coordinated signal timing plans for the signalized arterials. The procedures calculating delay and stops are based on Michalopoulos's analytical model derived from shock wave theory. The delay-offset relationship predicted from the algorithm produced consistent results with the delays venerated by TRANSYT-7F. From performance test, the delays estimated using the proposed a1gorithm are shown to be sensitive to the quality of progression as well as to traffic demand, link length, and turning flow ratio from upstream signal.

• Journal of the Ergonomics Society of Korea
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• v.22 no.2
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• pp.15-28
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• 2003

The one of the most important factors is the platoon design on developing AH3(Advanced Highway System), as it is related to traffic efficiency and drivers' safety. This study was evaluated that how much speed is comfortable for drivers and how long distance is appropriate for vehicular gap of platoon by measuring drivers' physiology signal and sensibility. A fixed-based AHS simulator was developed by using a real vehicle cockpit and the restructured part of Korean highway for human factors evaluation. The EEG(electroencephalogram), ECG (electrocardiogram) and GSR(Galvanic Skin Response) were measured for obtaining drivers' physiology signal according to the change of speed and gap. The brain wave(${\alpha},\;{\beta},\;{\delta},\;{\theta}$) by EEG, the response of the autonomic nervous system. the sympathetic and parasympathetic nervous system, by ECG, and relax-arousal situation by GSR were analyzed. The SD(Semantic Differential) method was also applied to evaluate drivers' sensibility by 5-grade evaluation scale with 96 adjectives. SSQ(Simulator Sickness Questionnaire) was used to measure the simulator sickness of pre and post driving, two times. As the results, drivers were comfortable with 120km/h speed of platoon and lam to 15m vehicular distance. The results of this study may differ from the adaption of the reality because of many parameters. However, the purpose of this study is show to significant results of the drivers' safety and the acceptability of human factors evaluation.