• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.44 no.10
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• pp.871-876
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• 2016

Abnormal odor similar with burning smell often appears at the cockpit in the beginning of ultra-sonic aircraft without air filter due to the heating of production materials remained at the bleed air duct. Sources of the odor should be removed by burn-in test before test flight in order to prevent pilot confuses order with emergency such as fire of engine. However, the present method cannot prevent abnormal odor completely at the high altitude flight because maximum temperature of flight is higher than it of burn-in-test. This paper suggests burn-in test improved based on the analysis of thermal conditions of high altitude flight. It is verified that the existing burn-in test cannot cover thermal conditions of high altitude flight due to the discontinuous flow control, high change rate of temperature per unit time and difference between limit temperature of condenser and turbine. In order to overcome the limitations of current methods, the new burn-in test with continuous flow control are suggested. The continuous flow control are achieved by ram air inlet control. The effect of suggested method are verified by ground tests and flight tests. The results show the bleed air temperature can cover the temperature of high altitude flight and prevent abnormal odor at the flight test.

• Journal of Distribution Research
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• v.11 no.2
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• pp.59-79
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• 2006

The purpose of this study is two folds; first. to identify the negative effect of customer dissatisfaction on trust and commitment. and second to examine the moderating effect of consumers' perceived equity created by various ways in which a company deals with his/her complaints. Our proposed model is empirically tested by a survey data collected from Internet shopping mall consumers who raised complaints. The simultaneous regression model is used to test the negative effect of customer dissatisfaction. To examine the moderating effect of equity, our study employs the group analysis of LISREL. The empirical result shows that customers' dissatisfaction. unless it is concerned with merchandise related dissatisfaction, influences on trust and commitment. Also, we find that consumers' perceived equity has a moderating effect on the relationship variables dissatisfaction and customer relationship variables including trust and commitment.

• Journal of the Korea Convergence Society
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• v.11 no.8
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• pp.369-379
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• 2020

This convergent study aimed to verify the mediating effect of organizational silence and manager's inclination to reject negative feedback in the relationship between organizational justice and turnover intention of Clinical Nurses. Participants were 250 nurses working at general hospitals with 300 hospital beds or more. Examination of the mediating effect of organizational silence showed a mediating effect of acquiescent silence when procedural justice affected turnover intention. Additionally, when interactional justice affected turnover intention, prosocial and acquiescent silence mediated it. Examining the moderated mediating effect of manager's inclination to reject negative feedback showed moderated mediation effect when procedural justice mediated the acquiescent silence and affected the turnover intention. Interactional justice had a moderated mediating effect when the mediation between prosocial and acquiescent silence affected turnover intention. Therefore, it is necessary to efficiently regulate the manager's inclination to reject negative feedback when organizational justice affects organizational silence and turnover intention.

• Communications for Statistical Applications and Methods
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• v.17 no.1
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• pp.79-88
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• 2010

Introductory statistic class proposes two tests for the equality of two population means according to the homogeneity of their variances. However, in practice, the variances are also unknown and practitioners often test their homogeneity before they do two sample t-test. This is also true in many popular statistical packages such as SAS and SPSS. In this paper, we study the type I error of this two stage procedure and propose a procedure to control it at a given significance level.

• Geotechnical Engineering
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• v.14 no.4
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• pp.129-140
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• 1998

Elasto-plastic finite element analysis of geotechnical boundary value problems necessitate the stress integration for the known strain increments. For the elasto-plastic constitutive model, the stress integration is generally achieved by numerical schemes, because analytical integration is impossible for general strain path. In this case, the accuracy of numerical stress integration has an important role on the overall accuracy of nonlinear finite element solution. In this study, the Sloan's substepping method which is one of explicit integration methods has been adopted and iris applicability has been checked. The unstability and inaccuracy of ifs results initiated from initial stress level were revealed. So. a new modified numerical integration method which employs the basic concept of modified Euler scheme for error control is proposed and accuracy and stability of the solutions are confirmed by triaxial test simulation.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2011.11a
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• pp.793-794
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• 2011

In launch process, propellants should be supplied with established temperature range for engine normal operation. In order to satisfy this temperature condition, propellant feeding systems should be considered some effects during operation. This paper studied liquid oxygen filling system operation process and cooling method of liquid oxygen during launch process.

• Water for future
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• v.29 no.1
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• pp.235-248
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• 1996

Apreliminary release scheme (PRS) is suggested for the operating rules during flood period to deal with conflicts between flood control and water conservation purposes. PRS can be used to decide the optimum releases, based on the forecast of an oncoming flood and flow rate at the control point downstream when comparing the variable restricted water level (VRWL) for flood control with the minimum required water level (MRWL) for conservation use. The model is applied to Chungju and Daechung reservoirs through simulations of the technique. This study illustrates the procedure to decide the time and size for preliminary releases. Also, effects of duration and magnitude of preliminary release are reviewed based on historicqal flood records. The simulation results indicate that the proposed PRS is effective for the managers to find optimal operating policies during flood period. The proposed scheme can be used with main release scheme using real-time operation on hour-to-hour basis to decide the release for a flood.

• Korean Journal of Forensic Psychology
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• v.12 no.2
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• pp.121-149
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• 2021

Statement Validity Analysis (SVA) is utilized in criminal investigations and the court to assess the credibility of given statements. During this procedure, the criteria for Criteria-Based Content Analysis (CBCA) are used to evaluate whether statements include the characteristics reflecting actual experiences about the event in question. Various studies had been conducted on the efficacy (classification rates) of CBCA criteria, yet the consistency of the findings was not investigated. In the current study, a meta-analysis was conducted with Korean CBCA studies reported from 2004 to 2020 (a total of fourteen studies). As a result, the total score of CBCA was found to successfully discriminate truth and fabrication. A significant positive (+) effect size was found with four criteria (3, 4, 10, and 12), all of which are classified as cognitive criteria. However, contrary to the underlying assumption for CBCA, criterion 18, classified as one of the motivational criteria, showed a significant negative (-) effect size. Meanwhile, moderator analyses were possible for eleven criteria (2~9, 12, 13, 15) and the results showed the significant effects of potential moderator variables such as the gender and status of the participants, study types and designs, number of raters, and publication status. The current results suggests that more careful attention is required to each criterion-especially the cognitive criteria-rather than the total CBCA score as well as the possible moderator effects in order to assess truthfulness of the statements. The implication, limitations, and suggestions for future studies were discussed.

• Transactions of the Korean Society of Mechanical Engineers
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• v.9 no.3
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• pp.360-366
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• 1985

본 연구에서는 주구조물의 진동이 관심있는 주파수 범위내에서 1 자유도계로 근사화될 수 있는 경우, 임의로 선택된 점탄성재료에 대하여 최적튜닝 및 최적댐핑효 과를 얻을 수 있도록 그 형상을 설계하고, 예비변형율을 조절하는 절차를 제시하고, 제안된 방법론을 외팔보와 집중하중으로 구성되는 1 자유도계 및 선반의 공구대에 적 용하여 공진감쇠 및 채터억제효과를 살펴 보았다.

• Proceedings of the Korea Water Resources Association Conference
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• 2006.05a
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• pp.740-745
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• 2006

최근 중 소규모의 도시개발, 택지개발, 유통단지, 산업단지, 주택단지 조성 등의 단지개발이 급속히 증가하고 있으며, 이에 따라 재해영향평가 및 사전재해영향성 검토도 증가하고 있는 실정이다. 단지개발은 보통 지구지정 또는 기본계획을 수립하여 개발계획 승인을 받고 실시설계를 통하여 실시계획을 승인을 받는 절차를 갖는다. 이에 효율적인 토지이용계획을 위하여 개발계획 승인전에 수십 회의 토지이용을 변경하고 또한 실시계획승인 전에도 토지이용계획은 수회의 변경을 통하여 이루어진다. 이에 재해영향평가 및 사전재해영향성검토를 초기단계에서 수행하는 실무자들은 토지이용계획의 빈번한 변경으로 인하여 저류지 규모 산정에 어려움을 가지고 있다. 단지개발의 토지이용계획 특성상 투수지역이 다소 있는 단지, 투수지역인 공원 녹지, 불투층인 도로 주차장으로 주로 구성된다는 공통점이 있다. 따라서 최근의 심의 완료된 재해영향평가보고서들을 인용, 각 단지개발의 토지이용계획도를 고려한 저류지 홍수조절용량을 산정하는 경험적이고 통계적인 다중회귀모형을 개발하였다. 금회 유도된 다중회귀모형식은 재해영향평가 및 사전재해영향성검토를 수행하는 실무자에게 행정계획단계뿐만 아니라 개발사업단계에서도 신속하게 저류지 규모를 개략 산정하고, 비전문가인 검토자가 신속히 홍수조절용량의 적정성을 검토하는데 매우 효과적으로 사용될 것으로 판단된다.