• Geomechanics and Engineering
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• 제34권6호
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• pp.597-609
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• 2023

One of the applicable methods for the stabilization of soil walls is the nailing system which consists of tensile struts. The stability and safety of soil nail wall systems are influenced by the geometrical parameters of the nailing system. Generally, the determination of nailing parameters in order to achieve optimal performance of the nailing system for the safety of soil walls is defined in the framework of optimization problems. Also, according to the various uncertainty in the mechanical parameters of soil structures, it is necessary to evaluate the reliability of the system as a probabilistic problem. In this paper, the optimal design of the nailing system is carried out in deterministic and probabilistic cases using meta-heuristic and reliability-based design optimization methods. The colliding body optimization algorithm and first-order reliability method are used for optimization and reliability analysis problems, respectively. The objective function is defined based on the total cost of nails and safety factors and reliability index are selected as constraints. The mechanical properties of the nailing system are selected as design variables and the mechanical properties of the soil are selected as random variables. The results show that the reliability of the optimally designed soil nail system is very sensitive to uncertainty in soil mechanical parameters. Also, the design results are affected by uncertainties in soil mechanical parameters due to the values of safety factors. Reliability-based design optimization results show that a nailing system can be designed for the expected level of reliability and failure probability.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2009년도 춘계학술대회 논문집
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• pp.1224-1228
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• 2009

The korean tilting train can increase the whole operating speed at a curved railroad, reducing the lateral acceleration with the tilting mechanism unlike the train developed before. However, increasing operating speed on the curved section, may cause safety problem of train travel. In general, a suspension system has important effects on driving safety. Therefore, optimization of suspension system is necessary to secure the safety of the tilting train. In this study, the tilting train suspension system has been optimized using Design of Experiments (DOE). First, the design parameter is selected using sensitivity analysis. A lateral acceleration which affects on the driving safety is chosen as the objective function. And the Design of Experiments (DOE) is used for optimization. As a result, new design parameters which show better performance than the existing suspension system has been suggested.

• 한국산학기술학회논문지
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• 제17권8호
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• pp.363-368
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• 2016

고장으로 인한 사고 등으로 막대한 피해를 초래할 수 있어 안전성이 중요시 되는 시스템을 안전중시 시스템이라고 한다. 시스템의 대형화, 복잡도 증가 및 무인화 운영 등으로 인해서 안전 위해 요소가 증가하고 있기 때문에 안전성 확보는 국방 및 다양한 산업분야에서 중요한 문제가 되었다. 이러한 이유로 미 국방부와 IEC 등 국제표준기구 등에서는 안전 관련 표준을 만들어서 안전성 확보의 강조 및 시스템 설계와 안전성 분석의 연계를 제시하고 있다. 또한 많은 연구들에서 안전성 분석 활동이 반영된 시스템 설계 프로세스, 방법론 및 도구가 개발되고 있다. 하지만 현재까지 제시된 시스템 설계와 안전성 분석의 통합 프로세스는 각 계층 수준에 존재하는 시스템 설계 정보를 어떻게 활용하는지 명확하게 제시하지 하지 못했다. 그 결과, 체계적인 방식으로 위험원을 식별하는데 어려움이 따르게 되었다. 이와 같은 문제점을 해결하기 위해서 본 연구에서는 각 계층 수준의 시스템 설계 정보를 기반으로 위험원을 식별하여 안전성을 향상 시키고, 여러 산업 분야에 적용 가능한 시스템 설계와 안전성 분석 활동의 통합 모델을 생성했다. 통합 모델이 체계적으로 안전성 분석을 수행할 수 있는 것을 보여주기 위해서 자동차 시스템을 대상으로 적용한 연구결과를 제시하였다.

• 한국산학기술학회논문지
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• 제18권11호
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• pp.31-45
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• 2017

철도 분야에서의 최근 수년간의 사고 통계에 의하면, 관련 기술 발전과 안전정보 관리시스템의 구축으로 사고발생 빈도가 현저히 줄고 있다. 그럼에도 불구하고 운영 및 유지보수에서의 오류와 안전설계에서의 결함으로 인한 사고는 지속적으로 발생하고 있다. 이에 따라 철도사고를 예방하기 위해, 철도차량 개발 시 안전성을 고려하는 설계 및 제작을 위한 지침이 작성되었고, 이와 더불어 안전 설계에 대한 독립적인 안전성평가의 수행에 대한 요구가 제시되었다. 이를 충족시키기 위해 철도시스템 개발업체는 안전성 활동 산출물인 Safety Case를 작성해야 한다. 이에 따라 Safety Case의 주요 항목 중 하나인 안전성 적용조건 (SRAC: Safety-Related Application Conditions)의 도출 및 관리에 대한 중요성이 커지고 있다. 지금까지 보고된 SRAC에 관한 연구 결과에서는 도출 절차의 간략성과 설계단계에서의 특정 안전성 활동 분석 방법에만 초점을 맞추고 있다. 이러한 방법은SRAC 항목 들을 빠르게 도출 할 수 있는 장점이 있지만, 안전성 측면에서 고려되어야 할 중요한 항목들이 누락될 위험이 존재한다. 이러한 문제를 해결하기 위하여 본 논문에서는 시스템 수명주기 전반에 걸쳐 안전성 설계 및 안전성 평가 활동을 수행하고 이를 기반으로 SRAC의 도출방법의 개선 방안을 제안한다. 이렇게 함으로써 SRAC를 보다 체계적으로 도출 및 관리를 수행할 수 있는데, 특히 설계 초기단계에서부터 SRAC를 고려함으로써 안전성 요구사항을 최대한 반영한 안전설계가 가능하다. 또한 철도신호시스템에 대한 적용사례 연구를 통하여 본 논문에서 제시하는 방법이 시스템 수명주기 전체에 걸쳐 SRAC를 고려함으로써 중요한 안전성 관련 항목들의 누락이 줄어들 수 있음을 보여준다.

• 대한조선학회논문집
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• 제46권1호
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• pp.69-77
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• 2009

Loss of human lives and properties including environmental damage due to large scale accidents requires change of our perception to marine safety. IMO is trying to re-establish overall marine safety system through long term plan such as GBS. Along this line, current regulation based safety evaluation is in process of changing into performance based methods, and for this transition, simulation based safety evaluation during design stage considering damage is highly necessary. In this paper, first, damage scenario is developed from IMO regulations and accident case studies. Then an integrated and simulation based safety evaluation prototype system considering both damage stability and structural safety is developed for the use during ship design process.

• 대한안전경영과학회지
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• 제10권1호
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• pp.23-31
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• 2008

Recently, there is a rise of accident by some defective products, especially it reported that a serious fact is a defect of design causing some problem since execute a product liability(PL), people who use products have been able to bo remunerated for a damage to those defects, so responsibilities of companies are rising more and more. Therefore, companies that are obligated to manufacture a safety product, and should make preparation for PL. For solving the problem, even though manufacturers tried to make a safety product ay mixed ways, it is seldom that its safety is considered from planning a design. This thesis has suggested a way aimed at improving a safety of products through considering a stage of a plan, by searching and analyzing the design-process in to each steps.

• 대한안전경영과학회지
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• 제15권3호
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• pp.61-69
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• 2013

According to ISO 26262 (the international standard on functional safety for automotive industry), the functional safety should be considered during the whole automotive systems life cycle from the design phase throughout the production phase. In order to satisfy the standard, the automotive and related industry needs to take appropriate actions while carrying out a variety of development activities. This paper presents an approach to coping with the standard. Analyzing the standard indicates that the safety issues of the automotive systems should be handled with a system's view whereas the conventional approach to solving the issues has been practiced with focus on the component's level. The aforementioned system's view implies that the functional safety shall be incorporated in the system design from both the system's life-cycle view and the hierarchical view for the structure. In light of this, the systems engineering framework can be quite appropriate in the functional safety development and thus has been taken in this paper as a problem solving approach. Of various design issues, the analysis and verification of the safety requirements for functional safety is a key study subject of the paper. Note, in particular, that the conventional FMEA (failure mode effects analysis) and FTA (fault tree analysis) methods seem to be partly relying on the insufficient experience and knowledge of the engineers. To improve this, a systematic method is studied here and the result is applied in the design of an ABS braking system as a case study.

• 한국철도학회논문집
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• 제6권1호
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• pp.1-9
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• 2003

This article proposes an integrated systems engineering and safety analysis model for safety-critical systems development. A methodology in system design for safety is considered during the early phase of the development life cycle of systems engineering process. The evolution of the design automation technology has enabled engineers to perform the model-based systems engineering. A Computer-Aided Systems Engineering(CASE) tool, CORE, is utilized to integrate the systems engineering model with a system safety analysis model. The results of the functional analysis phase can drive the analysis of the system safety. An example of Communications-Based Train Control(CBTC) system for an Automated Guided Transit(AGT) system demonstrated an application of the integrated model.

• 한국안전학회지
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• 제24권5호
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• pp.113-121
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• 2009

The objective of this study is to develop highway advisory radio service for road safety oriented system design of the point by regional groups or geographical distributions. To develop these highway advisory radio service, traffic information provided service areas, responds for incident and accident, and road condition in service sections based on traffic information of highway advisory radio service. This study contributes to service of traffic information for safety driving, which is transport congestion areas and recognition of traffic congestion status in advanced traffic information service. As result of this study, systematic design of the advanced highway and traffic safety guides to management systems by highway advisory radio service.

• 한국안전학회지
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• 제23권5호
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• pp.35-42
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• 2008

There are many efforts toward the development of next generation gas safety management systems to improve the assurance, availability, and efficiency of the extant systems. Among them, the application of ubiquitous technology, such as RFID and USN, to the system is regarded as a promising approach for enabling such an innovation. Recently the ubiquitous technology became much affordable and available than before thanks to the reduced production cost and wide proliferation of the ubiquitous devices. In this paper, we analyze the core requirements for the next generation gas safety management systems based on the ubiquitous technology, and present an architectural design of a middleware to facilitate the realization of the system. We formally define an event model and present how to specify various situations related to gas safety management using the proposed event model.