• Journal of Korean Society for Quality Management
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• v.24 no.2
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• pp.25-43
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• 1996

This paper presents the optimal and practical constant-stress accelerated life test plans for the lognormal lifetime distribution tinder assumptions of intermittent inspection and Type-I censoring. In an optimal plan, the low stress level and the proportions of test units allocated at each stress are determined under given inspection scheme and number of inspections such that the asymptotic variance of the maximum likelihood estimator of a certain quantile at use condition is minimized. Although the practical plan adopts the same design criterion, it involves three rather than two overstress levels in order to compromise the practical deficiencies of the optimal plan. Computational experiments are conducted to choose an allocation plan and a inspection scheme of the practical plan and to compare with test plans over a range of parameter values.

• Journal of Korean Academy of Fundamentals of Nursing
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• v.14 no.2
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• pp.157-165
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• 2007

Purpose: The purpose of this study was to investigate the plan to introduce a practical skills test as part of the national examination for nursing licensure. Method: The delphi method was used. The first set of data was collected by open questionnaire from universities and hospitals nationally. The second and third were collected by structured questionnaire. Results: The biggest problem for clinical Practice in nursing education was reported as the lack of opportunities for direct nursing practice. The biggest performance problem in job duties for novice nurses was reported as the lack of integrated problem solving skills in a clinical situation. The biggest problem with the current national examination was reported as the use memorizing solutions to test questions. It was suggested that the best plan to resolve problems with the national examination would be to develop test questions representative of the clinical setting and increase personnel in clinical education. About the introduction of a practical skills test as part of the national examination, 56.9% were in agreement and 38.5% disagreed. Conclusion: The current national examination has many problems when it comes to testing clinical competency. So, a practical skills test must be deferred to a future time. There are also many difficulties in presenting a real situation, therefore further research is needed in preparation for the introduction of a practical skills test.

• Journal of the Korean Data and Information Science Society
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• v.17 no.3
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• pp.945-952
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• 2006

Several accelerated life test plans use tests at only two levels of stress and thus, have practical limitations. They highly depend upon the assumption of a linear relationship between stress and time-to-failure and use only two extreme stresses that can cause irrelevant failure modes. Thus 3-level stress plans are preferable. When the lifetime distribution of test unit is exponential with mean lifetime $\theta_i$ at stress $x_i$, i=0, 1, 2, 3, we derive the optimum quadratic plan under the assumption that a quadratic relationship exists between stress and log(mean lifetime), and propose the compound linear plans, as an alternative to the optimum quadratic plan. The proposed compound linear plan is better than two other compromise plans for constant stress testing and nearly as good as the optimum quadratic plan, and has the advantage of simplicity.

• Proceedings of the Korea Society for Industrial Systems Conference
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• 2001.05a
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• pp.129-133
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• 2001

Accelerated life test is a viable method for identifying failure modes, incorporating design changes on an on-going basis during the early stages of automotive development program. The information from tests at high stress levels is extrapolated to obtain estimate of life at normal stress levels. This paper presents a practical method for accelerated life test to achieve a specified accuracy in estimating life at a design stress. Recommended and optimum plan are presented and the plans are illustrated with a simulated test data for the automotive power element example.

• Industrial Engineering and Management Systems
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• v.14 no.2
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• pp.183-195
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• 2015

In this paper, we propose a two-stage group acceptance sampling plan for generalized inverted exponential distribution under truncated life test. Median life is considered as a quality parameter. Design parameters are obtained to ensure that true median life is longer than a given specified life at certain level of consumer's risk and producer's risk. We also explore situations under which design parameters based on median lifetime can be used for other percentile points. Tables and specific examples are reported to explain the proposed plans. Finally a real data set is analyzed to implement the plans in practical situations and some suggestions are given.

• Journal of Applied Reliability
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• v.14 no.3
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• pp.182-190
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• 2014

This paper presents new practical accelerated life test plans with different censoring times at three levels of stress for Weibull and lognormal lifetime distributions, respectively. The proposed plans are compared with the corresponding two-level statistically optimal plans and three-level compromise and practical plans. Computational results indicate that new practical plans have been more precise and effective than the existing three-level plans under a constraint of total testing time. In addition, a procedure to determine useful ALT plans is illustrated with a numerical example.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.6
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• pp.89-97
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• 2016

This paper addresses the problem of the construction planning of artillery positions, for which we present an optimization model and propose a heuristic algorithm to solve problems of practical size. The artillery position construction plan includes the assignment of engineers to support the artillery and the schedule of the support team construction sequence. Currently, in the army, managers construct the plan based on their experience. We formulate the problem as a mixed integer program and present a heuristic that utilizes the decomposition of the mixed integer model. We tested the efficacy of the proposed algorithm by conducting computational experiments on both small-size test problems and large-size practical problems. The average optimality gap in the small-size test problem was 6.44% in our experiments. Also, the average computation time to solve the large-size practical problems consisting of more than 200 artillery positions was 79.8 seconds on a personal computer. The result of our computational experiments shows that the proposed approach is a viable option to consider for practical use.

• Journal of Korean Home Economics Education Association
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• v.22 no.3
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• pp.77-94
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• 2010

The purpose of this study was to develop a practical problem-based lesson plan for the "Understanding Myself and My Family" unit and to examine the effects of the lesson plan. Learning objectives and contents were selected, and a practical problem-based lesson plan for five sessions was developed and implemented. With 150 students participating in the study, a pre-test and post-test comprised of a questionnaire were conducted to explore the effectiveness of the lesson plan on the students' sex role characteristics, awareness of gender-role equity in occupational, familial and societal settings and of participation in household chores. Results from the post-test revealed that the students displayed androgynous sex-role characteristics, a heightened awareness of gender-role equity and a higher degree of participation in household chores after the five sessions. Assessment of the class was found to be very positive. Consequently the study showed that the lesson proved to be helpful for the students.

• Korean Journal of Agricultural Science
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• v.48 no.4
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• pp.855-863
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• 2021

The purpose of this study is to suggest an improvement plan for the National Technical Qualification Practical Evaluation focusing on National Competency Standards. First, in order to strengthen practical techniques such as field abilities and expertise, practical evaluation methods were applied to the National Competency Standards, referring to a learning module focused on field performance. Second, an expert advisory committee in the field of organic agriculture was utilized to compare, analyze, and match the competency unit and competency unit elements of the National Competency Standards with the national technical qualification examination standards in field of organic agriculture. In addition, in order to identify work in progress in the industrial field, share professional practice skills, and analyze facilities and equipment, we visited an organic agriculture industry site. Through this, a practical evaluation exam was developed. Subsequently, in order to confirm the adequacy of the developed exam, the pilot test assessment was conducted for those majoring in organic agriculture. Finally, as a feasibility study, a survey was conducted. Based on the results, greater technical job competency in the field of organic agriculture will contribute to strengthening knowledge in this field by suggesting an improvement plan for the national technical qualifications practical evaluation method in the field of organic agriculture.

• Korean Journal of Agricultural Science
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• v.48 no.4
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• pp.729-738
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• 2021

The purpose of this study was to suggest an improvement plan ultimately to develop practical evaluation methods for national technical qualifications in the field of seeds and horticulture based on the National Competency Standards. Through this, national technical qualifications can be strengthened in terms of professionalism in the seeds and horticulture field. In order to conduct this study, the national technical qualification currently in use was matched to certain competency units and competency unit elements of National Competency Standards. We then visited an industrial site to understand the practical factors related to the technical, facility and equipment aspects of the seeds and horticulture industrial field, after which a practical evaluation exam was developed. Also, for a feasibility study, a pilot test assessment was conducted for students majoring in seeds and horticulture, with a survey also conducted with field experts and an advisory committee consisting of experts in seeds and horticulture. Based on the results, by suggesting an improvement plan for a practical evaluation method leading to better national technical qualifications in the field of seeds and horticulture, it was shown to be possible to improve knowledge, technical, and literacy aspects. This can lead to the training of outstanding technical professionals. Ultimately, the results here are expected to contribute to the improvement of the seeds and horticulture industry.