• 제어로봇시스템학회논문지
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• 제15권3호
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• pp.337-345
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• 2009

The dependence of numerous systems on electronic devices is causing rapidly increasing concern over fault tolerance because of safety issues of safety critical system. As an example, a vehicle with electronics-controlled system such as x-by-wire systems, which are replacing rigid mechanical components with dynamically configurable electronic elements, should be fault￢tolerant because a devastating failure could arise without warning. Fault-tolerant systems have been studied in detail, mainly in the field of aeronautics. As an alternative to solve these problems, this paper presents the fuzzy hybrid redundancy system that can remove most erroneous faults with fuzzy fault detection algorithm. In addition, several numerical simulation results are given where the fuzzy hybrid redundancy outperforms with general voting method.

• 대한안전경영과학회:학술대회논문집
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• 대한안전경영과학회 2006년도 춘계공동학술대회
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• pp.237-249
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• 2006

Critical incident can be happened at any time, any places without any pre-notification. For minimizing the loss of the life safety, financial and so on caused by the risk, most of company needs a system what can activate the critical incident management plan to prevent, plan for and respond to events that become critical incident. But a lot of company still don't have such a detailed system in our country and almost company has no effective training way for to boot. This paper shows the way to activate the risk management system to work efficiently the plan. The training way, proposed by this paper, is a incident command simulator based on virtual reality and scenario generation software.

• 대한안전경영과학회지
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• 제8권4호
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• pp.25-37
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• 2006

Critical incident can be happened at any time, any places without any pre-notification. For minimizing the loss of the life safety, financial and so on caused by the risk, most of company needs a system what can activate the critical incident management plan to prevent, plan for and respond to events that become critical incident. But a lot of company still don't have such a detailed system in our country and almost company has no effective training way for to boot. This paper shows the way to activate the risk management system to work efficiently the plan. The training way, proposed by this paper, is a incident command simulator based on virtual reality and scenario generation software.

• 대한안전경영과학회지
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• 제17권3호
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• pp.195-204
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• 2015

The live fire test has been playing a critical role in evaluating the goals-to-meet of the weapon systems which utilize the power of explosives. As such, the successful development of the test systems therein is quite important. The test systems development covers that of ranges and facilities including system-level key components such as mission control, instrumentation or observation, safety control, electric power, launch pad, and so on. In addition, proper operational guidelines are needed with well-trained test and operation personnel. The emerging weapon systems to be deployed in future battle field would thus have to be more precise and dynamic, smarter, thereby requiring more elaboration. Furthermore, the safety consideration is becoming more serious due to the ever-increasing power of explosives. In such a situation, development of live fire test systems seems to be challenging. The objective of the paper is on how to incorporate the safety and other requirements in the development. To achieve the goal, an architectural approach is adopted by utilizing both the system components relationship and safety requirement when advanced instrumentation technology needs to be developed and deteriorated components of the range are replaced. As an evaluation method, it is studied how the level of maturity of the test systems development can be assessed particularly with the safety requirement considered. Based on the concepts of both systems engineering and SoS (System-of-Systems) engineering process, an enhanced model for the system readiness level is proposed by incorporating safety. The maturity model proposed would be helpful in assessing the maturity of safety-critical systems development whereas the costing model would provide a guide on how the reasonable test resource allocation plan can be made, which is based on the live fire test scenario of future complex weapon systems such as SoS.

• 대한안전경영과학회지
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• 제16권4호
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• pp.11-19
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• 2014

Modern systems development becomes more and more complicated due to the need on the ever-increasing capability of the systems. In addition to the complexity issue, safety concern is also increasing since the malfunctions of the systems under development may result in the accidents in both the test and evaluation phase and the operation phase. Those accidents can cause disastrous damages if explosiveness gets involved therein such as in weapon systems development. The subject of this paper is on how to incorporate safety requirements in the design of safety-critical systems. As an approach, a useful system structure using the method of design structure matrix (DSM) is studied while reflecting the need on systems safety. Specifically, the effects of system components failure are analyzed and numerically modeled first. Also, the system components are identified and their interfaces are represented using a component DSM. Combining the results of the failure analysis and the component DSM leads to a modified DSM. By rearranging the resultant DSM, a modular structure is derived with safety requirements incorporated. As a case study, application of the approach is also discussed in the development of a military UAV plane.

• 대한안전경영과학회지
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• 제14권4호
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• pp.107-116
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• 2012

The issues raised so far in the development of safety-critical systems have centered on how effectively the safety requirements are met in systems design. The systems are becoming more complex due to the increasing demand on the functionality and performance. As such, the integration of both the systems design and systems safety processes becomes more important and at the same time quite difficult to carry out. In this paper, an approach to solving the problem is presented, which is based on an integrated data model. To do so, the data generated from the inputs and outputs of the systems design and systems safety processes are analyzed first. The results of analysis are used to extract common attributes among the data, thereby making it possible to define classes. The classes then become the cores of the interface data model through which the interaction between the two processes under study can be modeled and interpreted. The approach taken has also been applied in a design case to demonstrate its value. It is expected that the results of the study could play a role of the stepping stone in extending to the architecture development of the integrated process.

• 항공우주시스템공학회지
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• 제7권2호
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• pp.29-34
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• 2013

Safety requirements for aircraft and system functions include minimum performance constraints for both availability and integrity of the function. These safety requirements should be determined by conducting a safety assessment. The depths and contents of aircraft system safety assessment vary depending on factors such as the complexity of the system, how critical the system is to flight safety, what volume of experience is available on the type of system and the novelty and complexity of the technologies being used. Requirements that are defined to prevent failure conditions or to provide safety related functions should be uniquely identified and traceable through the levels of development. This will ensure visibility of the safety requirements at the software and electronic hardware design level. This paper has prepared to study on promoting the efficiency of establishing hierarchical safety requirements from aircraft level function to item level through system safety processes.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2011년도 춘계학술대회 논문집
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• pp.1414-1419
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• 2011

In this paper we study the modeling to quantitatively assess the failure rate of USN system designed for fault-tolerant architecture, aiming at applying the world's best domestic USN technology to safety-critical railways. In order to apply the USN system to the safety-critical field like a train control sector that the failures of controllers may cause severe railway accidents such as train collision and derailment, the quantitative reliability and safety evaluation recommended in IEC 62278 must be preceded. We also develop the evaluation model for overall system failure rate for the distributed network structure, which is the characteristics of USN system. Especially, we allocate reliability targets to component units, and present an availability evaluation plan through the plan on the quantitative achievement of failure rate for sensor nodes, gateways, radio-communication network and servers, along with the failure rate model of the overall system considering network operational features.

• 한국산학기술학회논문지
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• 제17권9호
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• pp.308-313
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• 2016

사용자의 요구사항 증대와 기술의 발전으로 인해 현대 시스템은 계속해서 복잡해지고 있어 시스템 설계 오류 및 고장 등으로 인한 시스템 운용 중의 사고도 빈번해지고 있다. 특히 사고로 인한 인적 및 물적 피해가 심각할 수 있는 시스템을 안전중시 시스템이라고 부른다. 이러한 시스템에 대해서는 안전성을 확보하기 위한 특별한 노력이 필요한데 이에 부응하여 본 논문에서는 개발 초기 단계부터 안전성을 반영하면서 시스템 설계를 수행할 수 있는 방법을 연구하였다. 특히 안전 메타모델을 활용해서 기능의 고장 탐지를 수행할 수 있는 시스템 설계 방법을 제시하였다. 구체적으로 국제 안전 표준들을 참고하여 안전 데이터를 추출하고, 시스템 모델링 표준 언어인 SysML을 이용하여 안전 데이터 메타모델을 생성한 후, 시스템 설계에서 안전 데이터 메타모델을 효과적으로 활용하는 모델 기반 안전 시스템 설계 방법을 제시하였고, 이를 기반으로 안전요구사항 생성 및 시뮬레이션 방법에 관하여 논의하였다. 마지막으로 사례연구로서 자동차 시스템 설계에서 SysML 기반 모델링 및 시뮬레이션을 통해 기능 고장의 탐지나 안전 요구사항의 검증이 가능한 것을 보여 주었다. 본 연구에서 안전 데이터에 대한 메타모델의 활용을 통해 안전 데이터 및 정보의 구성 및 관리를 효율적으로 수행할 수 있는 것과, 메타모델 기반 시스템 설계와 시뮬레이션을 활용하여 설계 오류를 줄임으로써 요구사항에 맞는 시스템 설계를 할 수 있음을 제시하였다.

• 대한안전경영과학회지
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• 제16권1호
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• pp.69-77
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• 2014

The environment and requirements of modern war fields have been affected and thus changed by a variety of issues. To this end, the development of safety-critical weapon systems frequently need to meet those changes even in the operational phase. The necessity of the changes may be due to the preparation for mass-production or the request originated from the user military forces. To meet such a need can be even tougher in the development of safety-critical weapon systems since the integration of the requirements for both systems design and systems safety would make it troublesome. To handel the matter in this paper, utilization of architecture DB is proposed. Specifically, the situation in demand has first been analyzed and then a problem-solving process to accommodate the design changes has been constructed. In doing so, the concept of the aforementioned integration is particularly focused on the functional architecture, which could be a core concept of our approach to solving the problem. The result of a case study demonstrating the method studied using a computer-aided systems engineering tool is also presented.