• Journal of Internet Computing and Services
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• v.20 no.3
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• pp.1-11
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• 2019

Today's software systems are becoming larger and more complicated, and the risk of accidents and failures have also grown larger. Software failures and accidents in industrial fields such as automobiles, nuclear power plants, railroad industries, etc. may lead to severe damage of property and human life. The safety-related international standards, such as IEC 61508 have been established and applied to industries for decades. The safety life cycle specified in the standards emphasize the activities to develop safety requirements through hazard and risk analysis in the early stage of software development. In this paper, we propose 'Hazard Analysis Process based on STPA using SysML' in order to ensure the safety of software at the early stage of software development. The proposed hazard analysis can be effectively performed minimizing the loss of hazard by using the BDD and the IBD of SysML to define the control structure of a system. The proposed method also improves the specification of the safety constraints(requirement) by using SD. As a result, it is possible to identify the hazard without missing and identify the hazard scenarios in detail, and safety can be sufficiently ensured in the early stage of software development.

• Journal of Korea Society of Digital Industry and Information Management
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• v.7 no.4
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• pp.7-14
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• 2011

Infinite failure NHPP models presented in the literature exhibit either constant, monotonic increasing or monotonic decreasing failure occurrence rate per fault (hazard function). This infinite non-homogeneous Poisson process is model which reflects the possibility of introducing new faults when correcting or modifying the software. In this paper, polynomial hazard function have been proposed, which can efficiency application for software reliability. Algorithm for estimating the parameters used to maximum likelihood estimator and bisection method. Model selection based on mean square error and the coefficient of determination for the sake of efficient model were employed. In numerical example, log power time model of the existing model in this area and the polynomial hazard function model were compared using failure interval time. Because polynomial hazard function model is more efficient in terms of reliability, polynomial hazard function model as an alternative to the existing model also were able to confirm that can use in this area.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.66 no.9
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• pp.1379-1384
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• 2017

To guarantee safety and reliability, RAMS(Reliability Availability Maintainability and Safety) activity for a communication software in train communication network is studied. In this paper, preliminary hazard analysis in RAMS activities is studied for the communication software. Preliminary hazard analysis is done through library for communication software that the specification is defined by IEC 61375. The hazards are defined, then causes and consequence for each hazard are defined. The total 36 preliminary hazards are classified. For high severity hazards are changed to acceptable level by upgrading of system requirement specification.

• Journal of the Korean Society of Systems Engineering
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• v.17 no.1
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• pp.21-34
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• 2021

The use of Field-Programmable Gate Arrays (FPGAs) in the development of safety-related Human-Machine Interface (HMI) systems has gained much momentum in nuclear applications. Recently, one of the application areas for the Advanced Power Reactor 1400 (APR1400) is in the development of the advanced Component Interface Module (CIM) of the Engineered Safety Features Actuation System (ESFAS). Using systems engineering approach, we have developed a new FPGA-based advanced CIM software. The first step of our software development process involves the Preliminary Hazard Analysis (PHA) based on the previous CIM design. In this paper, we describe the qualitative approach used in performing the preliminary hazard analysis. The paper presents the methodology for applying a modified Hazard and Operability (HAZOP) procedure for the conduct of PHA which resulted in a qualitative risk-ranking scheme that informed the decisions for the safety criteria in the requirements specification phase. The qualitative approach provided the justification for design changes during the advanced CIM software development process.

• Proceedings of the KSRS Conference
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• 2003.11a
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• pp.522-524
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• 2003

This paper presents the interactive method of showing geological hazard maps and other related information using the new GIS software developed at the Geological Survey of Japan. The main purpose of the software is to easily provide information about geological hazards to a wide range of users. The software incorporates spatial and a-spatial data to interactively present the time, locations and extent of occurrence of geological hazards and other related information. Queries for hazard information can be easily done. Simulations of the occurrence of a particular geological event like the spread of volcanic ash during major volcanic eruptions can also be easily shown.

• Journal of IKEEE
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• v.16 no.2
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• pp.145-152
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• 2012

This paper is the Software Hazard Analysis (SWHA) which will study the managerial process and the technical methode and techniques inherent in the performance of software safety task within the Military Aircraft System Safety program. This SWHA identifies potential hazardous effects on the software intensive systems and provides a comprehensive and qualitative assessment of the software safety. The purpose of this paper is to identify safety critical functions of software in Military A/C. The identified software hazards associated with the design or function will be evaluated for risks and operational constraint to further improve the software design requirement, analysis and testing efforts for safety critical software. This common SWHA, the first time analysis in KOREA, was review all avionics OFP(Operational Flight Program), and focus only on software segments which are safety critical. This paper provides a important understanding between the customer and developer as to how the software safety for the Military A/C will be accomplished. It will also provide the current best solution which may as one consider the necessary step in establishing a credible and cost-effective software safety program.

• Journal of Korea Society of Digital Industry and Information Management
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• v.8 no.2
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• pp.1-10
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• 2012

In this study, software products developed in the course of testing, software managers in the process of testing software test and test tools for effective learning effects perspective has been studied using the NHPP software. The finite failure nonhomogeneous Poisson process models presented and the life distribution applied exponential and log shaped type hazard function. Software error detection techniques known in advance, but influencing factors for considering the errors found automatically and learning factors, by prior experience, to find precisely the error factor setting up the testing manager are presented comparing the problem. As a result, the learning factor is greater than autonomous errors-detected factor that is generally efficient model could be confirmed. This paper, a failure data analysis of applying using time between failures and parameter estimation using maximum likelihood estimation method, after the efficiency of the data through trend analysis model selection were efficient using the mean square error and coefficient of determination.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.11 no.6
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• pp.800-806
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• 2018

Software efficiency is the probability of failure free use in operating environments, and is the most fundamental factor affecting software system stability. The malfunction of the computer system used in the information technology field may cause a significant loss in the related industry. Therefore, in this study, we analyze the attributes of software reliability models that depend on various hazard functions based on finite fault NHPP model with software failure time data. The hazard function pattern of proposed model is constant for the Goel-Okumoto model, and the Minimax and Rayleigh models follow the incremental pattern, but the hazard function increase value of the Minimax model is smaller than that of the Rayleigh model and the Goel-Okumoto model. Also, the Minimax model was relatively efficient because the true value error of the mean value function m(t) and the mean square error (MSE) of the Minimax model were smaller than those of the Rayleigh and Goel-Okumoto models. The results of this study are expected to be useful for software developers as basic information about the hazard function.

• 한국지구물리탐사학회:학술대회논문집
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• 2006.06a
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• pp.247-252
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• 2006

This study analysed the sensitivity of the attenuation functions for the seismic hazard estimation. For the seismic hazard estimation, this study used HAZUS software, which is developed originally by FEMA(USA). The scenario earthquake ($M_w=6.0$) is located the Hongsung area, where one of the recent macro earthquakes occurred in 1978. The area for seismic hazard estimation is assumed to be Boryung city in Choongnam-do. Three attenuation functions were applied for the sensitivity analysis. The results show that the attenuation functions have much influences on the seismic hazard on the various types of buildings. Therefore the attenuation function is very important factor for the seismic hazard estimation.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.8 no.5
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• pp.345-353
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• 2015

There are many software reliability models that are based on the times of occurrences of errors in the debugging of software. It is shown that it is possible to do parameter inference for software reliability models based on finite failure model and non-homogeneous Poisson Processes (NHPP). For someone making a decision to market software, the conditional failure rate is an important variables. In this case, finite failure model are used in a wide variety of practical situations. Their use in characterization problems, detection of outlier, linear estimation, study of system reliability, life-testing, survival analysis, data compression and many other fields can be seen from the many study. Statistical process control (SPC) can monitor the forecasting of software failure and thereby contribute significantly to the improvement of software reliability. Control charts are widely used for software process control in the software industry. In this paper, proposed a control mechanism based on NHPP using mean value function of polynomial hazard function.