• Proceedings of the Korean Reliability Society Conference
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• 2005.06a
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• pp.251-257
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• 2005

Software system which is essential in operating the computer has gradually become an indispensable element in many aspects of our daily lives and an important factor in numerous systems. In recent years, software cost sometimes exceeds the cost of maintaining the hardware system. In addition to the cost necessary to develop the new software system and to maintain the system, the penalty costs incurred due to software failures are even more significant. In this paper, a cost model incorporating the warranty cost, debugging costto remove each fault detected in the software system, and delivery delay cost is developed. A software reliability model based on non-homogeneous Poisson process(NHPP) is established and the optimal software release policies to minimize the expected total software cost are discussed. Numerical examples are provided to illustrate the results.

• 한국IT서비스학회:학술대회논문집
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• 2005.11a
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• pp.345-355
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• 2005

As the portion of information systems(IS) budget to the total government budget becomes greater, the cost estimation of IS development and maintenance projects is recognized as one of the most important problems to be resolved for quantitative and efficient management of IS budget. The primary concern in the cost estimation of IS projects is to estimate software development cost. In this paper, we propose a new method to estimate software cost using support vector regression(SVR), which has attracted considerable attention because of its good performance and theoretical clearness. The paper is the first study which apply SVR to software cost estimation.

• 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.

• Journal of the Korea Society of Computer and Information
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• v.13 no.7
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• pp.1-9
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• 2008

In this paper, make a study decision problem called an optimal release policies after testing a software system in development phase and transfer it to the user. When correcting or modifying the software, because of the possibility of introducing new faults when correcting or modifying the software, infinite failure non-homogeneous Poisson process models presented and propose an optimal release policies of the life distribution applied log-logistic distribution which can capture the increasing! decreasing nature of the failure occurrence rate per fault. In this paper, discuss optimal software release policies which minimize a total average software cost of development and maintenance under the constraint of satisfying a software reliability requirement. In a numerical example, after trend test applied and estimated the parameters using maximum likelihood estimation of inter-failure time data, make out estimating software optimal release time.

• Journal of The Korean Association of Information Education
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• v.25 no.6
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• pp.871-878
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• 2021

This study analyzed the polarization of software education by analyzing the relationship between the average monthly total private education expenditure, software education expenditure, and academic achievement. For this purpose, data were collected and analyzed by surveying 2,780 parents of elementary school children nationwide. The results of this study are as follows: First, there was a statistically significant difference in children's academic achievement depending on whether or not they participated in software education. Second, the higher the children's academic achievement, the higher the percentage of participation in software private education expenditure. Third, there was a significant positive correlation between total private education expenditure and software-related private education expenditure. Fourth, although not statistically significant, there was a positive correlation between software private education expenses and academic achievement. In this study, software education provided by public education is not sufficient. For this reason, participation in private education and the amount of expenditure are increasing, and there is a gap in improving the main competencies of students according to household income.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.9 no.13
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• pp.29-32
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• 1986

A decision procedure to determine when computer software should be released after testing is described. This paper extends optimum release policies minimizing the total expected software cost with a scheduled software delivery time under reliability requirement constraint. Such cost considerations enable us to make a release decision as to when transfer a software system from testing phase to operational phase. The underlying model is software reliability growth model described by a nonhomogeneous poisson process. It is assumed that the penalty cost function due to delay for a scheduled software delivery time is linearly proportional to time. Numerical examples are shown to illustrate the results.

• Journal of Korean Society for Quality Management
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• v.27 no.3
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• pp.94-112
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• 1999

It is booming to use computer and information owing to the information society. As software applications have grown, so too has the importance of software quality. Therefore, software quality measurement and evaluation are necessary to satisfy the users who are using computers. The ISO/IEC 9126 defines six quality characteristics and twenty-one subcharacteristics including forty inter quality characteristics. We developed software measurement and evaluation technique using the check list in accordance with the ISO/IEC 9126 in design phase. We applied idea and concept of Total Quality Management in order to evaluate and measure the quality of software. Namely, it is the concept such as "you should do it right the first time." or "you have to build quality in the process." We executed the quantitative evaluation of software, also had shown the distinctive result in order that users and developers can find the errors easily. We evaluated the quality of academic softwares in order to verify developing technique at S college. As a result of the evaluation, this college has found it necessary to maintain the software as soon as possible because academic systems are not adequate for users at this present time.

• Journal of The Korean Association of Information Education
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• v.2 no.1
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• pp.35-51
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• 1998

Software reliability growth model is one of the evaluation methods, software quality which quantitatively calculates the software reliability based on the number of errors detected. For correct and precise evaluation of reliability of certain software, the reliability model, which is considered to fit dose to real data should be selected as well. In this paper, the optimal model for specific test data was selected one of among five software reliability growth models based on NHPP(Non Homogeneous Poission Process), and in result reliability estimating scales(total expected number of errors, error detection rate, expected number of errors remaining in the software, reliability etc) could obtained. According to reliability estimating scales obtained, Software development and predicting optimal release point and finally in conducting systematic project management.

• Proceedings of the Korean Reliability Society Conference
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• 2002.06a
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• pp.273-273
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• 2002

In this paper, we investigate a software release policy with software reliability growth factor during the warranty period by assuming that the software reliability growth is assumed to occur after the testing phase with probability p and the software reliability growth is not assumed to occur after the testing phase with probability 1-p. The optimal release policy to minimize the expected total software cost is discussed. Numerical examples are shown to illustrate the results of the optimal policy. And we consider a Bayesian decision theoretic approach to determine an optimal software release policy. This approach enables us to update our uncertainty when determining optimal software release time, When the failure time is Weibull distribution with uncertain parameters, a bayesian approach is established. Finally, numerical examples are presented for illustrative propose.

• Journal of Korea Society of Digital Industry and Information Management
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• v.9 no.2
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• pp.1-10
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• 2013

In this paper, make a study decision problem called an optimal release policies after testing a software system in development phase and transfer it to the user. In the course of correcting or modifying the software, finite failure non-homogeneous Poisson process model, presented and was proposed release policies of the life distribution, half-logistic and log-logistic distributions model which used to an area of reliability because of various shape and scale parameter. In this paper, discuss optimal software release policies which minimize a total average software cost of development and maintenance under the constraint of satisfying a software reliability requirement. In a numerical example, the parameter estimation using maximum likelihood estimation of failure time data make out, and software optimal release time was estimated.