• Toxicological Research
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• 제34권4호
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• pp.303-310
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• 2018

The methods of applied genetic toxicology are changing from qualitative hazard identification to quantitative risk assessment. Recently, quantitative analysis with point of departure (PoD) metrics and benchmark dose (BMD) modeling have been applied to in vitro genotoxicity data. Two software packages are commonly used for BMD analysis. In previous studies, we performed quantitative dose-response analysis by using the PROAST software to quantitatively evaluate the mutagenicity of four piperidine nitroxides with various substituent groups on the 4-position of the piperidine ring and six cigarette whole smoke solutions (WSSs) prepared by bubbling machine-generated whole smoke. In the present study, we reanalyzed the obtained genotoxicity data by using the EPA's BMD software (BMDS) to evaluate the inter-platform quantitative agreement of the estimates of genotoxic potency. We calculated the BMDs for 10%, 50%, and 100% (i.e., a two-fold increase), and 200% increases over the concurrent vehicle controls to achieve better discrimination of the dose-responses, along with their BMDLs (the lower 95% confidence interval of the BMD) and BMDUs (the upper 95% confidence interval of the BMD). The BMD values and rankings estimated in this study by using the EPA's BMDS were reasonably similar to those calculated in our previous studies by using PROAST. These results indicated that both software packages were suitable for dose-response analysis using the mouse lymphoma assay and that the BMD modeling results from these software packages produced comparable rank orders of the mutagenic potency.

• 한국정보전자통신기술학회논문지
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• 제9권6호
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• pp.566-572
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• 2016

소프트웨어 개발과정에서 소프트웨어 신뢰성은 매우 중요한 문제 중에 하나이다. 소프트웨어 고장현상을 분석하기 위하여 비동질적인 포아송과정에서 고장 발생 추이를 의미하는 위험함수가 고장시간에 독립적으로 일정하거나, 종속적인 경우, 즉 비-증가 또는, 비-감소하는 속성을 가질 수 있다. 본 연구에서는 소프트웨어 제품 테스팅 과정에서 고장 수명분포로서 어랑분포의 다양한 형상모수를 고려한 소프트웨어 개발 비용 분석에 대하여 연구되었다. 소프트웨어 고장현상을 분석하기 위하여 모수추정은 최우추정법이 사용되었다. 따라서 본 논문에서는 어랑분포의 형상모수를 고려한 소프트웨어 개발비용모형 분석을 위하여 소프트웨어 고장간격 시간자료를 이용하여 비교 및 평가하였다. 그 결과 형상모수에 따른 비용곡선을 비교 하였을 때 형상모형이 작을수록 비용이 많고 소프트웨어 최적 방출시간이 지연 됨을 알 수 있었다. 이 연구를 통하여 소프트웨어 개발자들에게 소프트웨어 형상모수에 따른 개발 비용을 탐색하는데, 기본적으로 도움을 줄 수 있는 사전정보의 역할을 할 수 있을 것으로 판단된다.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2007년도 추계학술대회 논문집
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• pp.638-645
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• 2007

Computers are increasingly being introduced into safety and reliability critical systems. The safe and reliable operation of these systems cannot be taken for granted. Malfunctions of these systems can have potentially catastrophic consequences and they have already been involved in serious accidents. Software fault prevention, fault tolerance, fault removal and fault forecasting are the techniques to be used, implemented and verified for embedded software in critical systems as the contributors to safety and reliability of the software. To use them when developing a software product, a relationship must be established between them and the development processes, the methods and techniques to be used to develop software, as well as with the different product architectures. Railroad signaling system software is a safety-critical embedded software with realtime and high reliability requirements. The primary purpose of the safety management is to prevent the loss of lives or physical damages arising from potential hazards in the railroad signaling system. This study provides a systematic approach to analysis of potential hazards for their management during the system life cycle to assure the identification and definition of the most appropriate hazards.

• 대한공간정보학회지
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• 제24권2호
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• pp.15-24
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• 2016

This study conducted an evaluation of the extent of debris flow damage using SINMAP, which is slope stability analysis software based on the infinite slope stability method, and FLO-2D, a hydraulic debris flow analysis program. Mt. Majeok located in Chuncheon city in the Gangwon province was selected as the study area to compare the study results with an actual 2011 case. The stability of the slope was evaluated using a DEM of $1{\times}1m$ resolution based on the LiDAR survey method, and the initiation points of the debris flow were estimated by analyzing the overlaps with the drainage network, based on watershed analysis. In addition, the study used measured data from the actual case in the simulation instead of existing empirical equations to obtain simulation results with high reliability. The simulation results for the impact of the debris flow showed a 2.2-29.6% difference from the measured data. The results suggest that the extent of damage can be effectively estimated if the parameter setting for the models and the debris flow initiation point estimation are based on measured data. It is expected that the evaluation method of this study can be used in the future as a useful hazard mapping technique among GIS-based risk mapping techniques.

• 한국산학기술학회논문지
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• 제15권5호
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• pp.2533-2538
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• 2014

본 연구에서는 노래방 화재의 위험성을 예측하기 위하여 2-zone model CFAST소프트웨어를 이용하여 해석을 수행하였다. 모델은 3차원 비정상 상태이다. 또한, CFAST의 해석 결과와 실제 화재 재현 실험결과를 비교 분석하여 CFAST의 정확성이 검증되었다. 해석 결과 화재가 발생된 방에서 화재발생 5분 이내에 산소농도는 10% 까지 감소하며, 이산화탄소 농도는 5%까지 증가하였다. 따라서 노래방과 같은 밀폐된 공간에서는 유독가스에 의한 질식으로 더 위험한 상황이 발생한다는 것을 예측할 수 있다.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2008년도 춘계학술대회 논문집
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• pp.1289-1293
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• 2008

A technology for inevitable integration as well as an ability of development of technology according to professional fields is needed and supported for securing technology in the era of international competition. In other words, advanced business technique and technology applied for streamlining of management are required and the relations between operations and systems could be clarified. This paper reviews the course for development of process used in the systems engineering and business administration and tries to seek the way of training professionals in a variety of fields for elevating domestic technologies in different fields to the international level. Particularly, it tries to get the way of overcome the present technical restriction that depends on imports through matching a hazard analysis method with the method above mentioned. Especially, it tries to present the way of contributing to securing software safety on the basis of the importance of development of process model that takes the life cycle into consideration.

• 한국산학기술학회논문지
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• 제17권4호
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• pp.382-391
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• 2016

철도와 같은 안전중시 시스템에 대해 체계적인 안전관리의 필요성이 점차 커지고 있어 IEC 61508, 62278, ISO 26262 등의 안전과 관련된 표준들이 제정되었고, 관련연구가 수행되고 있다. 그중 안전 프로세스의 중요한 활동인 위험원 분석에 대하여 다양한 연구가 수행되어 왔으나, 시스템설계 프로세스와의 구체적인 연계성이 부족하였다. 또한 기존의 위험원 분석방법은 시스템 설계가 상당 수준 진행된 하드웨어 및 소프트웨어 구성품 정보에 의존하기 때문에, 설계 변경에 많은 비용과 일정이 소요된다. 이러한 문제들을 해결하기 위해서 본 논문에서는 시스템 설계초기인 개념설계 단계에서 수행한 기능분석 결과를 안전 프로세스에서 직접적으로 활용하여 위험원을 분석하고 이를 바탕으로 위험을 줄이기 위해 필요한 안전요구사항을 생성하는 방법에 대하여 연구를 수행하였다. 설계 초기에 위험원 분석 및 안전요구사항의 도출을 수행함으로써, 향후 요구사항 변경 등 여러 요인으로 시스템 설계 및 안전 설계의 변경 시에 이를 반영하는데 있어서 시간 및 비용 관점에서 상대적으로 효율적인 접근 방법이 된다. 한편, 사례연구로서 본 논문에서 제시한 방법을 경전철 역사의 안전성을 확보하기 위한 요구사항의 도출에 적용하는 연구를 수행하였다.

• 디지털산업정보학회논문지
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• 제10권2호
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• pp.1-11
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• 2014

Software reliability in the software development process is an important issue. Software process improvement helps in finishing with reliable software product. In this field, SPC (Statistical process control) is a method of process management through application of statistical analysis, which involves and includes the defining, measuring, controlling, and improving of the processes. The proposed process involves evaluation of the parameter of the mean value function and hence the values of the mean value function at various inter failure times to develop relevant time control chart. In this paper, was proposed a control mechanism, based on time between failures observations using Rayleigh and Burr distribution property, which is based on Non Homogeneous Poisson Process (NHPP). In this study, the proposed model is reliable in terms of hazard function, because it is more efficient in this area can be used as an alternative to the existing model. Through this study, software developers are considered by the various intended functions, prior knowledge of the software to identify failure modes to feed to some extent shall be able to help.

• 한국농공학회논문집
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• 제58권2호
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• pp.21-29
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• 2016

This study conducted a basic design of system and interface which provide both of spatial and non-spatial data for water hazard information management. This helps to decide directions of the future integrated water hazard information platform and possible technical examinations of the web-based system for the realization of the prototype. For user friendly system, this study did a survey to investigate the data format, service environment, image processing level and visualization type that users prefer. Also, authorization range was set up by type of the user group. In the water hazard information platform, the data and analysis algorithm were classified by the fields. Furthermore, the platform was consisted with six block systems according to the function and the interface and designed to flexibly mount or modify the additional functions. For a basic design of the data exchange method and protocols, a prototype was constructed by using the spatial information web service technology. The portal service system to visualize and provide spatial data was designed by the WMS/WFS type of OGC standard interface and the FTP/HTTP interface type through open source GIS software for server environment.

• Earthquakes and Structures
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• 제15권6호
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• pp.605-616
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• 2018

In this paper, an extended Cloud analysis method is developed for seismic fragility assessment of existing highway bridges in the southeast Queensland region. This method extends the original Cloud analysis dataset by performing scaled Cloud analyses. The original and scaled Cloud datasets are then paired to generate seismic fragility curves. The seismic hazard in this region is critically reviewed, and the ground motion records are selected for the time-history analysis based on various record selection criteria. A parametric highway bridge model is developed in the OpenSees analysis software, and a sampling technique is employed to quantify the uncertainties of highway bridges ubiquitous in this region. Technical recommendations are also given for the seismic performance evaluation of highway bridges in such low-to-moderate seismic zones. Finally, a probabilistic fragility study is conducted by performing a total of 8000 time-history analyses and representative bridge fragility curves are generated. It is illustrated that the seismic fragility curves generated by the proposed extended Cloud analysis method are in close agreement with those which are obtained by the rigorous incremental dynamic analysis method. Also, it reveals that more than 50% of highway bridges existing in southeast Queensland will be damaged subject to a peak ground acceleration of 0.14 g.