• Electronics and Telecommunications Trends
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• v.14 no.4 s.58
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• pp.1-9
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• 1999

In this paper, we summarize the lessons learned from the applications of the software reliability engineering to a large-scale software project. The considered software is the software system of the TDX-10 ISDN switching system. The considered software consists of many components, called functional blocks. These functional blocks serve as the unit of coding and test. The software is continuing to be developed by adding new functional blocks. We are mainly concerned with the analysis of the effects of these software components to software reliability and with the analysis of the reliability evolution. We analyze the static characteristics of the software related to software reliability using failure data collected during system test. We also discussed a pattern which represents a local and global growth of the software reliability as version evolves. To find the pattern of software of the TDX-10 ISDN system, we apply the S-shaped model to a collection of failure data sets of each evolutionary version and the Goel-Okumoto (G-O) model to a grouped overall failure data set. We expect this pattern analysis will be helpful to plan and manage necessary human/resources for a new similar software project which is developed under the same developing circumstances by estimating the total software failures with respect to its size and time.

• Nuclear Engineering and Technology
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• v.40 no.5
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• pp.397-408
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• 2008

This paper describes the application of a software fault tree analysis (FTA) as one of the analysis techniques for a software safety analysis (SSA) at the design phase and its analysis results for the safety-critical software of a digital reactor protection system, which is called the KNICS RPS, being developed in the KNICS (Korea Nuclear Instrumentation & Control Systems) project. The software modules in the design description were represented by function blocks (FBs), and the software FTA was performed based on the well-defined fault tree templates for the FBs. The SSA, which is part of the verification and validation (V&V) activities, was activated at each phase of the software lifecycle for the KNICS RPS. At the design phase, the software HAZOP (Hazard and Operability) and the software FTA were employed in the SSA in such a way that the software HAZOP was performed first and then the software FTA was applied. The software FTA was applied to some critical modules selected from the software HAZOP analysis.

• Journal of Information Technology Services
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• v.5 no.1
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• pp.61-81
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• 2006

It is necessary to systematically explore the reform plans of the Software Industrial Promotion Law to systematically a representative high-added value future knowledge-based industry, software industry. The current Software Industrial Promotion Law provides only one provision on software business contract procedures, and the Civil Code, the National Contract law or Subcontract Fairness Law regulate other things, so the features of software industry are not properly reflected. To the contrary, the Information Communication Construction Law or the Construction Basic Law effectively prevent disputes by providing material and detailed provisions. Therefore the current software industry needs to be shifted from promotion to fundamental one. That is, as the software industry takes up a large portion at present, so the law should have basic procedural provisions. Also the National Contract Law governs only the contract procedures of public sector, so there should be business performance procedural provisions to regulate the software business formalities of civil sector. And the National Contract Law controls the sale, construction and service of articles at separate contract procedures, but software business contains construction and service characters simultaneously, so there should be business performance procedures fit for software business. Thus this study presented the legislative need and bill on the performance procedures of software business.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2007.10a
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• pp.725-728
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• 2007

Software security is about making software behave correctly in the presence of a malicious attack, even though software failures usually happen spontaneously in the real world. Standard software testing literature is concerned only with what happens when software fails, regardless of intent. The difference between software safety and software security is therefor the presence of an intelligent adversary bent on breaking the system. Software security for attacking the system is presented in this paper

• Journal of Distribution Science
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• v.13 no.1
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• pp.57-70
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• 2015

Purpose - Open source software has high utilization in most of the server market. The utilization of open source software is a global trend. Particularly, Internet infrastructure and platform software open source software development has increased rapidly. Since 2003, the Korean government has published open source software promotion policies and a supply promotion policy. The dynamism of the open source software market, the lack of relevant expertise, and the market transformation due to reasons such as changes in the relevant technology occur slowly in relation to adoption. Therefore, this study proposes an assessment model of services provided in an open source software service company. In this study, the service level of open source software companies is classified into an enterprise-level assessment area, the service level assessment area, and service area. The assessment model is developed from an on-site driven evaluation index and proposed evaluation framework; the evaluation procedures and evaluation methods are used to achieve the research objective, involving an impartial evaluation model implemented after pilot testing and validation. Research Design, data, and methodology - This study adopted an iteration development model to accommodate various requirements, and presented and validated the assessment model to address the situation of the open source software service company. Phase 1 - Theoretical background and literature review Phase 2 - Research on an evaluation index based on the open source software service company Phase 3 - Index improvement through expert validation Phase 4 - Finalizing an evaluation model reflecting additional requirements Based on the open source software adoption case study and latest technology trends, we developed an open source software service concept definition and classification of public service activities for open source software service companies. We also presented open source software service company service level measures by developing a service level factor analysis assessment. The Behavior-Structure-Evolution Evaluation Model (BSEM) proposed in this study consisted of a rating methodology for calculating the level that can be granted through the assessment and evaluation of an enterprise-level data model. An open source software service company's service comprises the service area and service domain, while the technology acceptance model comprises the service area, technical domain, technical sub-domain, and open source software name. Finally, the evaluation index comprises the evaluation group, category, and items. Results - Utilization of an open source software service level evaluation model For the development of an open source software service level evaluation model, common service providers need to standardize the quality of the service, so that surveys and expert workshops performed in open source software service companies can establish the evaluation criteria according to their qualitative differences. Conclusion - Based on this evaluation model's systematic evaluation process and monitoring, an open source software service adoption company can acquire reliable information for open source software adoption. Inducing the growth of open source software service companies will facilitate the development of the open source software industry.

• Journal of the Korea Society of Computer and Information
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• v.17 no.8
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• pp.123-133
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• 2012

Recently, as IT convergence has seen rapid growth the role and scope of software has been extended. many software companies are trying to improve the software quality and project outcome using software process improvement approach to cope with increasing software demands and software quality. Although software process improvement is difficult task which requires a lot of cost and time, there is still insufficient objective evidence on business benefits by its deployment. The purpose of this study is to analyze the relationship between software process improvement and software project productivity. That is, we investigated whether there is difference in software development productivity depends on software engineering level using statistical methods. We found that the software development productivity is different across the software engineering levels and the higher software engineering level can lead to improved software development productivity.

• 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.

• Journal of Information Technology Applications and Management
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• v.19 no.2
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• pp.181-196
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• 2012

The cost of software maintenance occupies about two thirds in the software lifecycle. However, it is not easy to estimate the cost of software maintenance because of various viewpoints about software maintenance, unclear estimation methods, and complex procedures. Until now, the cost estimation model has used compensation factors for software characteristic and environment on the basis of program size. Especially, most of existing models use maintenance rate of total software cost as a main variable. This paper suggests the software maintenance cost estimation model that uses the result of calculating real maintenance efforts. In this paper, we classify functional maintenance and non-functional maintenance as software maintenance activity type. For functional maintenance, present function point of target software is needed to evaluate. The suggested maintenance cost evaluation model is applied to a software case in public sector. This paper discusses some differences between our model and other modes.

• Journal of Electrical Engineering and Technology
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• v.2 no.3
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• pp.386-390
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• 2007

At recent times, an essential issue in the replacement of the old analogue I&C to computer-based digital systems in nuclear power plants becomes the quantitative software reliability assessment. Software reliability models have been successfully applied to many industrial applications, but have the unfortunate drawback of requiring data from which one can formulate a model. Software that is developed for safety critical applications is frequently unable to produce such data for at least two reasons. First, the software is frequently one-of-a-kind, and second, it rarely fails. Safety critical software is normally expected to pass every unit test producing precious little failure data. The basic premise of the rare events approach is that well-tested software does not fail under normal routine and input signals, which means that failures must be triggered by unusual input data and computer states. The failure data found under the reasonable testing cases and testing time for these conditions should be considered for the quantitative reliability assessment. We presented the quantitative reliability assessment methodology of safety critical software for rare failure cases in this paper.

• Journal of Integrative Natural Science
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• v.10 no.4
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• pp.249-257
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• 2017

The main focus when developing software is to improve the reliability and stability of a software system. We are enjoying a very comfortable life thanks to modern civilization, however, comfort is not guaranteed to us. Once software systems are introduced, the software systems used in the field environments are the same as or close to those used in the development-testing environment; however, the systems may be used in many different locations. Development of software system is a difficult and complex process. Generally, existing software reliability models are applied to software testing data and then used to make predictions on the software failures and reliability in the field. In this paper, we present an improved exponential NHPP software reliability model in different development environments, and examine the goodness-of-fit of improved exponential model and other model based on two datasets. The results show that the proposed model fits significantly better than other NHPP software reliability model.