• Journal of Korean Society for Quality Management
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• v.43 no.1
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• pp.57-66
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• 2015

Purpose: The purpose of this study is to apply the constrained Bayesian estimation methodology for product quality control process and prove the effectiveness of the product management by comparing with the well-known Bayes estimator through data performance result. Methods: The Bayes and constrained Bayes estimators were produced based on the theoretical background and for confirming the effectiveness of suggested application, the deviation index was defined and calculated for the comparison. Results: The statistical analysis result shows that applying the suggested estimation methodology, that is, constrained Bayes estimator improves the effectiveness of the index with regard to reduce the error by matching the first two empirical moments. Conclusion: Considering the advanced Bayesian approaches such as constrained Bayes estimation for the product quality control process, the newly defined deviation index reduces the error for estimating the parameter histogram which is reflected both location and deviation parameters and furthermore various Bayesian perspective approaches seems to be meaningful for managing the product quality control process.

• International Journal of Aerospace System Engineering
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• v.5 no.2
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• pp.16-22
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• 2018

An analysis has been made on the performance variation due to pressure drop change at propellant supply pipes of liquid rocket engine. The objective is to compare the effectiveness of control variables to tune the liquid rocket engine performance. The mode analysis program has been used to estimate the engine performance for different modes which is realized by controlling the flow rate of propellant. The oxidizer of combustion chamber, the fuel of combustion chamber, the oxidizer of gas generator and the fuel of gas generator are the independent variables to control engine thrust, engine mixture ratio and temperature of gas generator product gas. The analysis program is validated by comparing with the powerpack test results. The error range of compared variables is order of 4%. After comparison of tuning effectiveness it is turned out that the pressure drop at oxidizer pipe of gas generator and pressure drop at combustion chamber fuel pipe and the pressure drop at the fuel pipe of gas generator can effectively tune the thrust of engine, mixture ratio of engine and temperature of product gas from gas generator respectively.

• Korean Journal of Child Studies
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• v.32 no.6
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• pp.81-94
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• 2011

The purpose of this study was to develop an Integrative Group Counseling Program to reduce depression, suicide ideation, and stress of high school students, and to examine the effectiveness of such a program. In order to evaluate the effectiveness of the program developed, an experimental group which was exposed to the program and a control group without exposure to the program were compared. The program was administered over eight weekly sessions, each session lasting ninety minutes. The subjects in this study consisted of twenty students. An experimental group and a control group were organized with ten students in each. For data processing, SPSS 16.0 was used to analyse statistical results. The Center for Epidemiological Studies-Depression Scale, the Suicidal Ideation Scale, and the Stress Scale were used in a pre-test, post-test, and follow-up test. The findings of this study were as follows : The treatment group exhibited a significant statistically decreasing degree of depression, suicide ideation, and stress levels in comparison to the control group. The results of the study indicated the effectiveness of this newly developed Integrative Group Counseling Program on reducing depression, suicide ideation, and stress levels.

• Geomechanics and Engineering
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• v.11 no.6
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• pp.847-865
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• 2016

In this study, a series of geotechnical centrifugal tests were conducted to investigate the effectiveness of settlement control of two types of rigid pile structure embankments (PRSE) in collapsible loess under high-speed railway embankments. The research results show that ground reinforcement is required to reduce the post-construction settlement and settlement rate of the embankments. The rigid pile structure embankments using rigid piles can substantially reduce the embankment settlement in the construction of embankments on collapsible loess, and the efficiency in settlement reduction is affected by the pile spacing. The pile-raft structure embankments (PRSE) have much stronger ability in terms of the effectiveness of settlement control, while the pile-geogrid structure embankments (PGSE) provides rapid construction as well as economic benefits. Rational range of pile spacing of PRSE and PGSE are suggested based on the requirements of various railways design speeds. Furthermore, the time effectiveness of negative skin friction of piles and the action of pile-cap setting are also investigated. The relevant measures for improving the bearing capacity and two parts of transition zone forms as positive control mean have been suggested.

• Safety and Health at Work
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• v.13 no.2
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• pp.235-239
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• 2022

Background: The purpose of present study was to determine the effectiveness of training program based on job stress management in NEDSA and line staff. Methods: The study method of this study was quantitative and quasi-experimental research Methods: From the statistical population (all employees of the NEDSA and line staff in 2020-2021), 30 of these people were selected by judgmental sampling method and considering the inclusion and exclusion criteria. The participants were first matched based on age and education and were randomly divided into experimental and control groups. First, pre-test was taken from both groups (Job Stress Questionnaire). The experimental group was presented with a job stress management training package and no protocol was presented in the control group. After the sessions, post-test was received from both groups (experimental and control). After two months, a follow-up test was performed. Results: The results were entered into SPSS-24 software and analyzed. The results of repeated measure showed high effectiveness of the job stress management package (researcher-made). The results showed that the job stress management training package showed 67.5% effectiveness and also the training effect of job stress management training was stable for two months (follow-up). Conclusion: Based on these results, Training program based on stress management can be effective in military staff.

• Educational Technology International
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• v.14 no.1
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• pp.75-108
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• 2013

The purpose of this study is to find a way to improve digital textbooks for self-regulated learning by applying cognitive scaffolding designs to an elementary math digital textbook and examining the effectiveness of the system. Hence this study was conducted in two steps. First, a framework for scaffolding design was devised by examining the problems and difficulties students encounter when using a mathematics digital textbook. Second, after the digital textbook was revised by applying the scaffolding design frameworks, the effectiveness of the scaffolding framework was examined by comparing students' achievement levels in an experimental group and that of students in a control group. Seventy fifth-graders participated in this study. Students were divided into two groups: an experimental group and a control group. The students in the experimental group studied with the revised version of the digital textbook and the students in the control group studied with the original version of the digital textbook. The students received a pretest before the experiment. After the experiment, they took an achievement test and completed a usability questionnaire. The data were analyzed by ANCOVA with the SPSS Windows version. The results revealed that the students who used the revised program (to which design strategies for scaffolding were applied) showed higher levels of achievement than those who used the original version. In addition, students in the experimental group generally showed higher scores on the usability survey, which consisted of four sub-categories such as 'effectiveness', 'efficiency', 'satisfaction', and 'learnability'. There was a statistically significant effect on 'efficiency'. These results implied that scaffolding strategies were effective for mathematics learning through the use of an elementary digital textbook.

• Transactions of the Korean hydrogen and new energy society
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• v.10 no.1
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• pp.19-26
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• 1999

The effectiveness of a double-tube heat exchanger has been investigated experimentally. This problem is of particular interest in the design of the heat exchanger in a hydrogen liquefaction system. Temperature, pressure, and mass flow rate for hydrogen were measured both in inner tube and in annulus of a double-tube heat exchanger. The effectiveness could be evaluated from the measured temperature and mass flow rate. It is found that the effectiveness increases with an increase in the heat transfer area of a double-tube heat exchanger and with a decrease of the heat capacity ratio. But the increase rate of the effectiveness decreased with a decrease of the heat capacity ratio. Therefore, it is presented that a criterion for selecting the heat exchanger length and heat capacity ratio to obtain the effectiveness required in a hydrogen liquefaction system.

• Journal of Korean Academy of Nursing
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• v.35 no.8
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• pp.1485-1492
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• 2005

Purpose. The present study aims to verify the effectiveness of the reality therapy for patients with schizophrenia. Methods. It is designed as a quasi-experimental study by which a nonequivalent control group pretest-posttest is conducted. The test was conducted with 30 patients with schizophrenia who were hospitalized at a mental hospital in South Korea. Fifteen of the patients participated in the reality therapy program while another 15 in the control group. The effects are measured by marking scores in the areas of the locus of control, self-esteem, and problem-focused stress coping of each participant. Results. The general characteristics and dependent variables related to outcome variables were controlled to be equal between the two groups. It turns out that the internal locus of control, self-esteem, and problem-focused stress coping are statistically significant. Conclusion. Findings show that the reality therapy caused positive changes in terms of the internal locus of control, self-esteem, and problem-focused stress coping of the observed schizophrenic patients.

• The Transactions of the Korean Institute of Electrical Engineers P
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• v.66 no.4
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• pp.206-212
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• 2017

In this paper, using the power system information obtained from real-time monitoring device, to analyze the voltage stability margin index and described the voltage stability control scheme for voltage stability enhancement. Based on the utilization of the voltage stability monitoring index based on local information provided by the PMU(Phasor Measurement Unit), the purpose of the plan is to control the system stably in real time. In order to apply the load control scheme, the voltage stability margin is calculated using the data acquired through the PMU installed in each load bus. If the voltage drops below a certain level, load control is performed for each. The effectiveness of the voltage stability control measures is applied to the actual KEPCO system to analyze the effectiveness.

• Proceedings of the KSR Conference
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• 2010.06a
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• pp.857-865
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• 2010

Recently the demand of the driverless rolling stock is increasing with advancement of the stable communication technique and control technique. The automatic train operating system has advantages which takes low operating cost and is able to dispose elastically in demand. Beside it provides high safety and effectiveness because it will be able to control power, signal and communication system from Operation Control Center and the safety and effectiveness are high. The establishment of PSD, Platform Screen Door, is advanced in the goal which is passenger safety, fire protection, noise and dust reduction etc. When but, two advanced systems also have risks of operation delay and accident when two systems are not controlled smoothly. Thus, I'll introduce control method between onboard controller, door control unit in rolling stock and PSD controller to help system design.