• Journal of Information Technology Applications and Management
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• v.22 no.3
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• pp.143-167
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• 2015

This paper addresses the issue how the total life cycle cost may be minimized and how the cost should be allocated to the acquirer and developer. This paper differentiates post life cycle change (PLCC) endeavors from PLCC activities, rigorously classifies PLCC endeavors according to the result of PLCC endeavors, and rigorously defines the life cycle cost of a software product. This paper reviews classical definitions of software 'maintenance' types and proposes a new typology of PLCC activities too. The proposed classification schemes are exhaustive and mutually exclusive, and provide a new paradigm to review existing literatures regarding software cost estimation, software 'maintenance,' software evolution, and software architecture from a new perspective. This paper argues that the long-term interest of the acquirer is not protected properly because warranty period is typically too short and because the main concern of warranty service is given to removing the defects detected easily. Based on the observation that defects are caused solely by errors the developer has committed for software while defects are often induced by using for hardware (so, this paper cautiously proposes not to use the term 'maintenance' at all for software), this paper argues that the cost to remove defects should not be borne by the acquirer for software.

• Journal of Information Technology Applications and Management
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• v.24 no.2
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• pp.71-80
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• 2017

Software reliability is one of the most elementary and important problems in software development In order to find the software failure occurrence, the instantaneous failure rate function in the Poisson process can have a constant, incremental or decreasing tendency independently of the failure time. In this study, we compared the reliability performance of the software reliability model using the parameters of Pareto life distribution with the intensity decreasing pattern and the shape parameter of Erlang life distribution with the intensity increasing and decreasing pattern in the software product testing. In order to identify the software failure environment, the parametric estimation was applied to the maximum likelihood estimation method. Therefore, in this paper, we compare and evaluate software reliability by applying software failure time data. The reliability of the Erlang and Pareto life models is shown to be higher than that of the Pareto lifetime distribution model when the shape parameter is higher and the Erlang model is more reliable when the shape parameter is higher. Through this study, the software design department will be able to help the software design by applying various life distribution and shape parameters, and providing basic knowledge using software failure analysis.

• Journal of Information Technology Applications and Management
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• v.19 no.2
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• pp.135-147
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• 2012

Software architecture, as a blueprint for the system, should provide a robust foundation for design, implementation, and maintenance, for communication and documentation, and for reasoning about important system properties. Software architecture plays a central role during the whole software life-cycle. There are so diverse definitions of the software architecture, however, and there is no common agreement about what software architecture is. Examining 27 'published' definitions of software architecture, we synthesize an extensive model on the essential elements of software architecture, which consists of components, interaction among components, well-formed structure, reasons, and various perspectives. Further, we explore the possibility of unifying diverse software architecture definitions into a software architecture life-cycle model.

• Proceedings of the KSR Conference
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• 2007.11a
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• pp.777-783
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• 2007

Life cycle costing is one of the most effective cost approaches when we choose a solution from series of alternative so the least long-term cost ownership is achieved. Life cycle costing in railway industry has been focused on the prediction of investment for railway vehicles. But in today, the life cycle cost, LCC, prediction on the aspect of operation and maintenance cost through whole life cycle is highly necessary. In this paper, we present a strategy for the development of life cycle cost estimation software on the aspect of maintenance strategies of railway vehicle. For this purpose, we suggested a structure of LCC software based on the UNIFE LCC model. And we developed a pilot version of software to evaluate the LCC model that we suggested for railway vehicle. We performed LCC analysis on the brake module of metro vehicle in case study and concluded that the software and model developed in this research could enough to support engineers in choosing better cost effective solutions from many alternatives.

• Journal of Korea Multimedia Society
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• v.11 no.6
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• pp.891-902
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• 2008

The software once developed enters in to the $2^{nd}$ phase of its useful operational life, where it performs its functions for which it has been developed. This is an important phase of software life, wherein the developers and users have to assess the performance of the software to prolong its operational life with efficiency, effectiveness and economy. Performance of the software is based on the measurement of the quality characteristics to ascertain that it is meeting or exceeding the needs of customers in terms of its functionality, usability, efficiency, reliability, availability, maintainability, portability etc. These software quality attributes defined under ISO 9126 provide an overall good framework for assessing the performance of the software. This paper describes a Software Performance Assessment (SPA) model using the Goal-Question-Metric (GQM) paradigm which has been applied to the operational software in real context with successful results.

• Journal of Applied Reliability
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• v.12 no.3
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• pp.187-199
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• 2012

In general, accelerated life testing is performed to reduce testing time. But it is difficult to apply accelerated life testing to a system besides components. This paper developed a software which estimates reliability measures of the system from results of accelerated life testing of components building the system. This software can handle the system with a large number of components and complex topology. Multiple failure modes of a component were also considered in this software. Based on the software, reliability measures of a gearbox example at several conditions were estimated from the accelerated life testing results of three components of the gearbox.

• 한국경영정보학회:학술대회논문집
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• 2007.11a
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• pp.487-492
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• 2007

This research focuses on the development and empirical validation of a model of software piracy behavior on the basis of deterrence theory, expected utility theory and the theory of reasoned action. The total of sample numbered 86 and PLS (Partial Least Square) was utilized for analysis. The test of this study revealed that punishment severity was the greatest significant factor to influence to software piracy and subjective norms was also significantly related to it. However punishment certainty and software cost do not significantly affect to software piracy.

• International Journal of Safety
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• v.3 no.1
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• pp.38-46
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• 2004

This paper introduces the software life-cycle V&V (verification and validation) tasks for the KNICS (Korea nuclear instrumentation and control system) project. The objectives of the V&V tasks are mainly to develop a programmable logic controller (PLC) for safety critical instrumentation and control (I&C) systems, and then to apply the PLC to developing the prototype of an engineered safety features-component control system (ESF-CCS) in nuclear power plants. As preparative works for the software V&V, various kinds of software plans and V&V task procedures have been developed according to the software life-cycle management. A number of software V&V tools have been adopted or developed to efficiently support the V&V tasks. The V&V techniques employed in this work include a checklist-based review and inspection, a requirement traceability analysis, formal verification, and life-cycle based software testing.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.25 no.2
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• pp.19-26
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• 2002

In this paper a software program is given for food product life (shelf life) estimation. There are many modules of related operations, considering the characteristic of food industry so that users can easily use and understand the software, and we make the related data referenced In data base. In food industry acceleration tests depend on food deterioration differential equations. Based on such equations, etc, this paper suggests a shelf life estimation software program.

• Proceedings of the KSME Conference
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• 2003.11a
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• pp.1340-1345
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• 2003

In this paper, an integrated optimal design software system for structural components has been developed which interfaces existing commercial codes for CAD, CAE and Optimization. They include specialized optimal design software codes such as iSIGHT and VisualDOC, optimization module imbedded in CAD software developed by CAD developers, and optimal design software systems based on API of commercial CAD software. The advantages of the CAD imbedded optimal design approach and those of specialized optimal design software are taken to develop the system. The user defines optimal design formulation in the user interface for problem definition in the CAD control stage, where design variables are directly selectable from the CAD model and various properties and performance functions defined. The commercial CAD codes, Open I-DEAS are used for the development. The resulting software is minimally connected to CAD and CAE systems while keeping maximum independence from each other. This assures flexibility and freedom for problem definition. Fatigue life optimization is taken as a nontrivial application area. As a specific example, the shape design of a knuckle part of an automobile is performed, where the minimum fatigue life over the material domain in terms of the number of cycles of a curb strike are maximized under the constraint of not exceeding the current mass. The fatigue life has been improved by four times of the initial life. The developed software is illustrated to maintain the advantages of existing optimal design software systems while improving independency and flexibility.