• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.10 no.5
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• pp.372-379
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• 2017

Software reliability factor during the software development process is elementary. Case of the infinite failure NHPP for identifying software failure, the occurrence rates per fault (hazard function) have the characteristic point that is constant, increases and decreases. In this paper, we propose a reliability model using the chi - square distribution which depends on the degree of freedom that represents the application efficiency of software reliability. Algorithm to estimate the parameters used to the maximum likelihood estimator and bisection method, a model selection based on the mean square error (MSE) and coefficient of determination($R^2$), for the sake of the efficient model, were employed. For the reliability model using the proposed degree of freedom of the chi - square distribution, the failure analysis using the actual failure interval data was applied. Fault data analysis is compared with the intensity function using the degree of freedom of the chi - square distribution. For the insurance about the reliability of a data, the Laplace trend test was employed. In this study, the chi-square distribution model depends on the degree of freedom, is also efficient about reliability because have the coefficient of determination is 90% or more, in the ground of the basic model, can used as a applied model. From this paper, the software development designer must be applied life distribution by the applied basic knowledge of the software to confirm failure modes which may be applied.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.10 no.5
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• pp.469-475
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• 2017

Software reliability is one of the most basic and essential problems in software development. In order to detect the software failure phenomenon, the intensity function, which is the instantaneous failure rate in the non-homogeneous Poisson process, can have the property that it is constant, non-increasing or non-decreasing independently at the failure time. In this study, was compared the reliability performance of the software reliability model using the Landely lifetime distribution with the intensity function decreasing pattern and Erlang lifetime distribution from increasing to decreasing pattern in the software product testing process. In order to identify the software failure phenomenon, the parametric estimation was applied to the maximum likelihood estimation method. Therefore, in this paper, was compared and evaluated software reliability using software failure interval time data. As a result, the reliability of the Landely model is higher than that of the Erlang distribution model. But, in the Erlang distribution model, the higher the shape parameter, the higher the reliability. 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 software reliability attributes data and basic knowledge to software reliability model using software failure analysis.

• Journal of Korean Society of Environmental Engineers
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• v.28 no.8
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• pp.829-835
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• 2006

The composition, source, and regional concentration of polybrominated diphenyl ethers(PBDEs) were measured in pine needles with several sites in Korea. Homologs specific analysis confirmed that hepta-BDE(bromodiphenyl ethers) through deca-BDE were predictive indicator for total PBDEs concentration(Pearson's correlation coefficient r>0.96, p<0.001). Deca-BDE were detected in relatively very high concentration compared to other PBDE congeners in all samples. The similarity of between congeners profile to those of Bromkal 70-5DE and DE-71, the commercial mixture of PBDEs, indicates these mixtures are source of PBDEs observed in these sites. Also, BDE-47, -99, -100, -206, -207, and -209 were the dominant congeners in all samples, suggesting that the widely used commercial penta- and deca-BDE technical mixture were the original sources. However, Pearson's correlation coefficients of between BDE-209 and BDE-47, -99, -100 were insignificant, which implied that tetra-BDE and penta-BDE may originate from secondary sources such as air-plant partition in manner similar to that of the PCBs, while deca-BDE formulation still has primary sources.

• International Journal of Highway Engineering
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• v.7 no.4 s.26
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• pp.21-30
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• 2005

Traffic volume data have been used for the plan, the design, and the operation of highway. Since 1955, traffic survey has been nation- widely carried out at national highway and the regular survey in national highway has been conducted at the intersections of highways. However, it is critical issue to select the priority of the regular survey because it is almost impossible to conduct regular survey at all intersections of national highways. In this study, MCDM(Multiple Criteria Decision Making) using AHP(Analytic Hierarchy Process) was applied to decide the priority of the regular survey. The following standard variables for determining the priority was selected the highway plan variables[AADT, VKT, Peak Hourly Volume, Location of highway from Urban], the highway design variables[Volume(pcu), Directional Traffic Volume, Heavy Vehicle Rate], and the highway operation variables[Speed, Density, V/C]. The standard variables were quantified and normalized. Using the Eigen vector method, the weighted values of each hierarchy based on the pair-wise comparison values from the questionnaire survey were calculated. The selection of the priority of regular survey was dependent on the size of the product of the weighted values for each hierarchy and the normalized values for the standard variables. Finally, the priority of regular survey of the intersections of national highways was determined according to the order in the size of the product of two values.

• Journal of Korean Home Economics Education Association
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• v.30 no.3
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• pp.151-173
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• 2018

The purposes of this study was to identify the magnitude and direction of the effects of Practical Reasoning Instruction (PRI) on students' achievements in Home Economics classes using the meta-analysis method and to examine whether the effects of PRI vary across publication status, study design, year of the studies, school level, gender of students, type of students' achievements, content area, location where the interventions of PRI were conducted, and duration. Thirty-four primary studies with 44 effect sizes were analyzed with calculation method of Becker(1988). A funnel plot method result revealed no publication bias. The results of this meta-analysis are as follows. First, PRI was more effective than traditional instruction on students' achievements. A summary statistic was 0.60 with a standard error of .074, which means that an increase of about two-third of a standard deviation beyond what would be expected from traditional instruction was gained from PRI intervention. Second, categorical and regression analyses were employed to find the sources of variance and moderators that predict the effects of PRI. The moderator analyses revealed no statistically significant effects of publication status, study design, school level, gender of students, type of students' achievements, and duration. Content area, location where the interventions of PRI were revealed to be moderators. It was concluded that PRI was effective in improving students' achievements regardless of publication status, study design, year of the studies, school level, gender of students, type of student achievement, and duration.

• Journal of The Korean Association For Science Education
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• v.18 no.1
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• pp.43-60
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• 1998

The purpose of this study is to compare and analyse the elementary school science curriculum and textbooks of South and North Korea, then gather the fundamental sources for the establishment of elementary school science curriculum after Unification of Korea by clarifying the difference and the likeness in educational objectives, contents, teaching methods of both Korean elementary school sciences. Based on this comparison and analysis, this study tried to give the concrete suggestions for the elementary school science curriculum and textbook development after Unification. For this, analyses were carried out for the curriculum managing systems, subject organization, education goal, emphasis on each field, teaching-learning and evaluation method. Besides, this study compared and analysed the elementary school science textbook development and distribution system, apparent format, content organization, ratio of content categories, content scope and level and the related terms appeared in both Korean elementary school science textbooks. The result of this study showed a lot of differences in the educational objectives, contents, and educational method of the elementary school science between South and North Korea. The grasping of these differences and the exact understanding about what causes these differences and how the differences are made must be the necessary work for the science curriculum establishment, especially for elementary school science curriculum and textbook development, after Unification.

• Journal of Digital Contents Society
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• v.15 no.3
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• pp.439-447
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• 2014

This study seeks to validate the development and the effectiveness of a web-based online education program used to enhance communication skills of college students. Communication skills are important skills demanded of college students seeking employment that play a significant role in self-introduction, presentations, interviews, and continuous interaction in the workplace. 105 students in the third and fourth year of D University were selected for the experimental and control groups in which the experimental group met once a week for one semester in 2013 for a total of 16 weeks(twenty minutes) while the control group was left untreated. The variable of effectiveness for the results of this study was based on the criteria of communication and performance behavior skills. The results show that the communication skills and performance behavior skills proficiency of the experimental group compared to the control group, have made dramatic improvements. Therefore, the web-based communication skills training program for college students was found to be effective in the enhancement of the communication skills of college students. For the future, we expect further sustained development of various effective capabilities programs along with the promotion of web-based online education.

• Journal of Hospice and Palliative Care
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• v.18 no.2
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• pp.136-147
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• 2015

Purpose: This study was conducted to evaluate the effects of integrated palliative care intervention on quality of life in terminally ill patients. Methods: A comprehensive literature search was performed via PubMed, Cochrane Library CENTRAL, LWW (Ovid), CINAHL and several Korean databases. The main search strategy was to combine terms indicating palliative care intervention, presence of terminal illness and study design. Methodological quality was assessed using Cochrane's Risk of Bias for randomized studies and Risk of Bias Assessment tool for non-randomized studies. Data were analyzed by the Stata 10 program. Results: Eight clinical trials met the inclusion criteria with a total of 356 participants. Integrated palliative care interventions were administered for a mean of 6.5 weeks, 5.6 sessions and an average of 47.8 minutes per session. Effect sizes were heterogeneous, and subgroup analysis was done. Integrated palliative care interventions had a significant effect on quality of life (ES=1.83, P=0.018, $l^2=92%$), spiritual well-being (ES=0.78, P=0.040, $l^2=0$), depression (ES=0.86, P<0.001, $l^2=32$) and anxiety (ES=0.69, P=0.041, $l^2=71.1$). But integrated palliative care interventions had no significant effect on pain (ES=0.365, P=0.230, $l^2=69.8$). Conclusion: Results support findings that integrated palliative care interventions were helpful in lessening depression and anxiety and improving quality of life and spiritual well-being, however, the interventions did not assist pain management in terminal cancer patients. These findings suggest that various integrated palliative care interventions can assist terminal cancer patients with better quality of life in the socio-psycho-spiritual dimension.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.35 no.2
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• pp.417-426
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• 2015

The representative design elements of the road geometric structure are longitudinal slope, horizontal curve radius, super elevation, and transition curve. According to the function of a road, the design standards of these elements is applied by diverse combinations of them. This study divided expressway into homogeneous segments based on longitudinal slope and horizontal curve radius. And then, data required for analysis were matched to each segment, and the safety performance function was built by using the established data. crash modification factors which can explain traffic accident exposure rate were calculated. When the threshold value of horizontal curve radius R=1,000 m was set to 1.0, the crash modification factors at R=300 m was calculated as 1.33, which means that the accident exposure rate is increased by 33%. When the threshold value of the longitudinal slope 0% was set to 1.0, the crash modification factors demonstrated that the accident exposure rate decreases on the upward slope and the accident exposure rate increases on the downward slope. The results of this study can be used as basic information in the design of expressway geometries during the improvement or the construction of expressways.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.19 no.9
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• pp.1719-1729
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• 1994

In this paper, an adaptive CAC(Connection Admission Control) method is proposed. The adaptive CAC uses traffic estimates derived from both traffic parameter specified by user and cell flow measurements. Traffic estimation using user-specified parameters is performed at every moment of connection request or connection release by recursive formula which makes real-time calculation possible. Traffic estimation using cell flow measurement is carried out when the number of connected calls does not change during a measurement reflection period-renewal period. The most import ant thing for the traffic estimation using cell flow measurement is the determination of the length of a renewal period to trace a real traffic flow with an allowable time lag and the measurement reflection ratio(MRR) both to reduce the portion of overestimation and to avoid underestimation of real traffic flow. To solve these problems, the adaptive CAC updates renewal period and MRR adaptively according to the number of connections and the elapsed time after last connection or release respectively. Performance analysis for the proposed method is evaluated in several aspects for the cases of both homogeneous and heterogeneous bursty traffic. Numerical examples show the adaptive CAC method has the better performance compared with conventional CAC method based on burst model from the both utilization and QOS point of view.