• 한국자동차공학회논문집
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• 제9권2호
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• pp.176-184
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• 2001

The VDC(Vehicle Dynamics Control) is a control system whose target is to improve vehicle stability under critical motion. The system has a good potential of becoming a standard active safety unit in passenger vehicles since it can be implemented on top of the ABS/TCS system with little extra cost. This, however, is possible only when the signals that the VDC system demands can be obtained with sufficient accuracy. In this research, estimators for the road friction coefficient and body sideslip angle have been designed. The two variables have great influence upon performance of the VDC system but not directly measurable. For the estimator design, the Newton method and the nonlinear observer theory have been exploited. The performance of the estimator have been verified via simulations on critical driving conditions.

• 대한안전경영과학회지
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• 제4권1호
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• pp.105-114
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• 2002

Nowadays, most companies seek after the greatest profit by means of offering the goods which consumers want timely and efficiently and minimizing the cost of inventory and distribution channel which amounts to the great portion of total cost. And according as EC(Electronic Commerce) market has increased rapidly, SCM(Supply Chain Management) for EC become one of the most important facts for companies, therefore this paper suggest SCM scheme which EC, especially B to C, is added to the existing commerce system. This paper uses internet for information integration of distribution channel which is away from one another and applies TOC(Theory of Constraint)'s DBR(Drum-Buffer-Rope) Scheduling for synchronization through the whole supply chain. It is possible to synchronize the whole supply chain by means of making the speed of manufacturing and distribution to be controlled by consumer's order which is received in distribution center, and inventory and loss of sales opportunities are minimized by constant. Buffer Management. If inventories in distribution center is short, then it needs to search CCR(Capacity Constraint Resource) in supply chain and to control the speed of manufacturing and distribution according to the ability of CCR. This paper applies PT(Partial Transshipment) strategy for Delivery from distribution center to store or cyber consumer. the strategy this paper suggests chooses neighbour area from area which each distribution center takes charge, and then makes product ordered by cyber consumer which lives in the chosen area to be delivered according to inventory of distribution center.

• 대한안전경영과학회지
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• 제12권4호
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• pp.145-151
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• 2010

It seems that a primary concern of the project-based company, which provides a large scale product or service over long term period, is to run a successful project through systematic project process control and control costs. One of the typical project control methods is Earned Value Management System(EVMS) which analyses the precess through performance measurement. Even though the EVMS is a highly efficient tool in the managerial aspect, it cannot easily determine the Planned Value(PV), Actual Cost(AC), or Earned Value(EV) due to the indistinct criteria and extensive data. The accurate calculation of AC in particular, is the basic of project management, but most companies record direct personnel expenses or direct expenses only. Since they calculate indirect expenses based on the estimated ratio, it limits the systematic project management that reflects changes in profit and loss of a company. This study introduces a EVMS for project management and its actual case based on EVMS and ERP system which some additional modules are installed for performance measurement. It is expected that this new method enables a company to save time and effort, and also to improve transparency by specifying expense items in detail and to switch quarterly settlement to monthly by reducing the time of calculation.

• 자동차안전학회지
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• 제11권3호
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• pp.30-36
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• 2019

This paper suggests a car-following algorithm for urban environment, with multiple target candidates. Until now, advanced driver assistant systems (ADASs) and self-driving technologies have been researched to cope with diverse possible scenarios. Among them, car-following driving has been formed the groundwork of autonomous vehicle for its integrity and flexibility to other modes such as smart cruise system (SCC) and platooning. Although the field has a rich history, most researches has been focused on the shape of target trajectory, such as the order of interpolated polynomial, in simple single-lane situation. However, to introduce the car-following mode in urban environment, realistic situation should be reflected: multi-lane road, target's unstable driving tendency, obstacles. Therefore, the suggested car-following system includes both in-lane preceding vehicle and other factors such as side-lane targets. The algorithm is comprised of three parts: path candidate generation and optimal trajectory selection. In the first part, initial guesses of desired paths are calculated as polynomial function connecting host vehicle's state and vicinal vehicle's predicted future states. In the second part, final target trajectory is selected using quadratic cost function reflecting safeness, control input efficiency, and initial objective such as velocity. Finally, adjusted path and control input are calculated using model predictive control (MPC). The suggested algorithm's performance is verified using off-line simulation using Matlab; the results shows reasonable car-following motion planning.

• 정보과학회 논문지
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• 제43권6호
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• pp.662-667
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• 2016

차량 내 전기전자제어시스템이 급격히 증가하면서 이로 인한 안전사고가 이슈로 부각되고 있다. 그러므로 차량의 안전성을 확보하기 위해서는 개발 초기에 PHA, HAZOP 등을 활용하여 위험원을 식별하고, 이를 예방하기 위한 안전 메커니즘이 구현되어야 한다. 특히, HAZOP은 가이드워드 기반의 체계적인 방식으로 널리 활용되고 있다. 하지만, 시스템이 제공하는 최상위 기능으로부터 오동작을 찾아내기 때문에, 동작 과정상의 위험원을 충분히 식별하지 못한다. 또한 충분히 식별되지 않은 위험원으로부터 안전 요구사항을 정의하기 때문에 테스트케이스 설계에도 제한이 있다. 이에 본 연구에서는 시스템의 동작과정 정의에 유용한 사용사례 기술서와 HAZOP을 적용한 위험원 식별 그리고 안전 요구사항 기반의 테스트케이스 설계 방안을 제안한다. 본 연구의 효용성을 검증하기 위해 차량의 스마트키 제어시스템 사례를 제시하고, 기존 HAZOP 기반의 위험원 분석 결과와 비교한다. 본 연구를 적용하는 조직은 시스템 개발 초기에 위험원 및 안전 요구사항을 충분히 식별하고, 테스트케이스를 설계함으로써 개발 비용을 줄이고, 시스템 품질을 높일 수 있을 것으로 기대한다.

• 한국응급구조학회지
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• 제6권1호
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• pp.87-102
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• 2002

Injury has now replaced disease as the biggest single cause of death in children after their first birthday. Each day child dies from preventable, unintentional injury and the medical cost of these injury is increasing remarkably. It is necessary to develope injury prevention models to explain, predict, manage, evaluate and analyze the information about accident. The purpose of this paper is, firstly, to investigate parent's actions regarding safety measures at home and secondly, to identify the influencing factors of parents' safety behaviors. The selection of such factors is guided by the theoretical framework of the Pender's Health Promotion Model. Method ; The questionnaire was developed on the basis of other investigations, through pilot testing, peer review, and review by field health workers. The questionnaire was completed by 231 mothers of young children. Data was collected between April and May 2002. Variable Use of three different domains of safety behavior, safety habits, supervision and perception of safety devices, were listed. Mothers were self reported on internal locus of control, mother & child relationships, and marital intimacy. Also the elements of the Health Promotion Model: perceived benefit, barrier, threat, and self-efficacy, were surveyed. Results & discussion The results indicate that most parents take considerable action to reduce household hazards. The constructs derived from the Model were statistically significant differences for a small part of the variables on parental behavior to reduce hazards in the home, such as age, education, economic status, self-efficacy, perceived benefit, internal locus of control. Future studies ought to include social influences, such as expectations, perceived norms, knowledge, and child-related variables, relevant to parental safety measures in their home.

• 전기학회논문지
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• 제63권5호
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• pp.703-712
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• 2014

To improve the efficiency and safety of railway systems, the train control system has been considerably evolved from the ground-equipment-based control system (e.g. track circuit, interlocking system, etc.) into the on-board-equipment-based control system. In addition, this train control system enables the rolling stock to intelligently control the trackside facilities by introducing the information and communication technologies (ICT). Accordingly, since the ICT-based train control system makes the railway system be simplified (i.e. the heavy ground-equipment can be removed), the efficient and cost-effective railway system can be realized. In this paper, we perform the feasibility test of the ICT-based train control system via a simulation. To this end, we have developed the prototypes of the on-board controller and wayside object control units which control the point and crossing gate and performed the integrated operation simulation in a testbed. In this paper, before the field test of the on-board-controller-based train control system, we perform the Consecutive operation test for prototypes of the on-board controller, wayside object control units and local control computer.

• International Journal of Naval Architecture and Ocean Engineering
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• 제13권1호
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• pp.306-320
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• 2021

To ensure safe port operations around the world, it is important to solve mooring problems. In particular, the many ports that face open seas have difficulties with long-period waves. As a countermeasure, the installation of a breakwater is proposed for mooring safety. However, this often cannot be put into practice because of financial issues. Instead, port terminals control berthing schedules with weather forecasting. However, mooring problems remain unsolved, because of inaccurate wave forecasting. To quantify the current situation, numerical simulations are presented with ship motions, fender deflections, and rope tensions. In addition, novel simulations for mooring ropes are proposed considering tension, friction, bending fatigue, and temperature. With this novel simulation, the optimal mooring method in terms of safety and economic efficiency was confirmed. In terms of safety, the optimal mooring method is verified to minimize dangerous mooring situations. Moreover, the optimal mooring method shows economic benefits and efficiency. It can help to reinforce the safety of port terminals and improve the efficiency of port operations.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 1998년도 춘계학술대회논문집
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• pp.40-44
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• 1998

In this study, the subframe of passenger car is developed by typical analysis and carsh simulations. According this results, energy absorption and barrier froce is very important to control passenger safety and deformation shape. For that purpose, it is most effective to absorb energy more tailor welded blanks(TWB) subframe than non-TWB. The subframe with TWB is simulated, in which reduced stamping parts, weight reduction and cost down.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1987년도 한국자동제어학술회의논문집; 한국과학기술대학, 충남; 16-17 Oct. 1987
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• pp.307-311
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• 1987

This paper presents a ship navigation system and automated equipments on ship board, whose technology has been quite rapidly developing in recent years. The ship owners and builders are much interested in ship automation systems, due to their comfort, safety and lower life cycle cost in ship operation. Here the basic technology and structure of the system are described, also taken into account is the future trend on the development of the system.