• 대한안전경영과학회지
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• 제16권3호
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• pp.369-376
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• 2014

The national Logistics Information system has been rapidly developed on account of the dramatic improvements in the military's logistics support system and supply support system, making a transition from manual work system to computerized work system. Supply level, however, does not reflect these changes in the overall logistics environment and still retains the state it was in the 1970s. This research uses the accumulated data from the equipment maintenance information system developed in the year 2009 to analyze RWT(Requisition Wait Time) and CWT (Customer Wait Time). The analysis estimated the realistic transportation and ordering time and led to the conclusion that the differentiated ASL operation system that considers demand level should be adopted instead of the uniform ASL employment system.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2002년도 추계학술대회 논문집(I)
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• pp.202-207
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• 2002

The rubber type AGT system is operated by driverless that signaling is CBTC type. The system function is acomplished exactly to obtain the safety and reliability of system and the system is designed to minimize risk. In order to design the system, the functional analysis is performed. Recently functional analysis is performed by RDD-100 which is used and verified by aerospace, military, etc. Therefore, The design tool RDD-100 is used to perform functional analysis in AGT system development project.

• 대한기계학회논문집A
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• 제30권9호
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• pp.1070-1077
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• 2006

In the present study, sizing and shape optimizations are performed based on the reduced system of large-scaled problem. In the analysis part to achieve efficiency and reliability of computation, two-level condensation scheme is applied. In the construction of reduced system of large scaled problems, it is much more efficient to use sub-domain method. Thus, in the present paper, two-level reduction method combined with sub-domain method is employed. Once the reduced system is constructed, it is straightforward to obtain design sensitivities from the analysis results of the reduced system We use semi-analytic method to obtain design sensitivities. Performance of the efficiency and reliability of the present reduction method in the structural optimization problem is demonstrated through the numerical examples. The present framework of reduction method should serve as a fast and reliable design tool in analysis and design of large-scaled dynamic problems.

• 산업경영시스템학회지
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• 제41권4호
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• pp.91-100
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• 2018

The setting of values on door hinge mounting compensation for door assembly tolerance is a constant quality issue in vehicle production. Generally, heuristic methods are used in satisfying appropriate door gap and level difference, flushness to improve quality. However, these methods are influenced by the engineer's skills and working environment and result an increasement of development costs. In order to solve these problems, the system which suggests hinge mounting compensation value using CAE (Computer Aided Engineering) analysis is proposed in this study. A structural analysis model was constructed to predict the door gap and level difference, flushness through CAE based on CAD (Computer Aided Design) data. The deformations of 6-degrees of freedom which can occur in real vehicle doors was considered using a stiffness model which utilize an analysis model. The analysis model was verified using 3D scanning of real vehicle door hinge deformation. Then, system model which applying the structural analysis model suggested the final adjustment amount of the hinge mounting to obtain the target door gap and the level difference by inputting the measured value. The proposed system was validated using the simulation and showed a reliability in vehicle hinge mounting compensation process. This study suggests the possibility of using the CAE analysis for setting values of hinge mounting compensation in actual vehicle production.

• 산업경영시스템학회지
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• 제40권3호
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• pp.18-26
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• 2017

Defense industries which require high reliability need an optimized quality management system with well-planned implementation. And the government should examine the overall status of defense industries, then establish practical policies with a proper support plan in required areas to upgrade the quality management level of manufacturers. Thus, DTaQ developed the model for 2 years from 2014, which specialized in quality management level analysis for defense industries. And a survey has been undertaken with that model by DTaQ and Korea Research Center in 2016. The surveyed companies randomly sampled among those which have more than 30 employees and delivery history over past 3 years, and finally 106 defense industries were selected. This paper present survey method and indexes for survey of defense industry quality management level. The survey was conducted in the order of planning, data collection and data processing, and the validity and reliability of the data were verified to increase objectivity of survey results. The survey contents mainly consist of system quality and management quality. System quality includes Product Development Management, Production Operation Management, supply chain quality management, Safety & Environment Management and Reliability Management, on the other hand, management quality includes Strategic Leadership, Human Resource Management, Customer Market Management and Information & Knowledge Management. Thus this proposes the current overall quality management status of the 106 defense industries and shows level differences by company sizes and manufacturing sectors based on the result of survey. Specifically, this paper enables to track the areas which need prompt government support with the policy directions to make quality management level higher. Therefore, it is expected that this can be used as reference data in establishing quality policies for military supplies in the future.

• 대한안전경영과학회지
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• 제8권2호
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• pp.115-128
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• 2006

The study analyzes those relations of customer service level of each sales branch, level of cooperations among branches, and overall system-wide service level for an item. Under the continuous review method, each sales branch places an order to the outside supplier, and the each branch receives the order quantity after elapsing a certain lead time. Under these circumstances, those branches with stockout condition may be supplied by other branches with keeping stocks to cover the shortages. This policy generally increases the system-wide customer service level for an item throughout cooperations for the safety plan among branches. Therefore, in the context of inventory policy, the decision rules to determine the proper branch levels of service and cooperation levels of service are important goals in terms of attaining desired system-wide service level. This research has suggested the method and procedure to reach above goals.

• 한국산업정보학회논문지
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• 제22권2호
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• pp.15-25
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• 2017

A System can be more Dependable from some types of Threats if the Dependability Level Against the Threat on the System is Increased. However, The Dependability-performance Tradeoff should be Considered because the Increased Dependability may Degrade the Performance of the System. Therefore, it is Efficient to Temporally Increase the Dependability Level to High only when an Threat is Predicted on the System in a Short time while Maintaining the Level in Low or mid in Normal Situations. In this Paper, we Present a Threat Prevention Strategy for a Networked Node by Dynamically Changing the Dependability Level According to the Threat Situation on its Logically/physically Neighboring Nodes. As case Studies, we Employ our Strategy to an Internet Server Against TCP SYN Flood Attacks and to a Checkpoint and Rollback System Against Transient Faults. Our Performance Analysis Shows that our Strategy can Effectively Relieve the Damage of the Failure without Serious Performance Degradation.

• 한국인터넷방송통신학회논문지
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• 제16권6호
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• pp.1-7
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• 2016

새로운 정보통신 기술의 발전과 더불어 보안 위협도 나날이 지능화 고도화되고 있다. 본 논문은 네트워크 장치나 사물인터넷 경량 장치에서 일련의 주기를 통해 연속적으로 입력되는 시계열 데이터를 통계적 기법을 활용하여 분석하고, 분석 정보를 기반으로 장치의 이상 유무나 비정상 징후를 탐지할 수 있는 시스템을 제안한다. 제안 시스템은 과거에 입력된 데이터를 기반으로 1차 비정상 탐지를 수행하고, 시간 속성이나 그룹의 속성을 기반으로 저장되어있는 시계열 데이터를 기반으로 신뢰구간을 설정하여 2차 비정상 탐지를 수행한다. 다단계 분석은 판정 데이터의 다양성을 통해 신뢰성을 향상시키고 오탐율을 줄일 수 있다.

• 한국농공학회지
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• 제43권4호
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• pp.69-78
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• 2001

In this study optimal analysis of pipe network was performed using linear and non linear analysis method for complex real pipe network system of Mungyeong water purification field system which consists of 70 nodes and 86 elements. From the examination result of total flow which is distributed to each pipe, it is found that KYPIPE2 Model supplies less amount than NLAM. It is known that dynamic water level and pressure head of KYPIPE2 Model and NLAM are nearly in accordance with each other from each method of the pipe network analyses, and appeared that both methods of analysis shows high reliable result since the distribution of dynamic water level for every node is the short range of EL. 205.0m~EL. 210.0m besides the pressed dynamic water level. The analysis results of pressure in the methods of pipe network analysis for KYPIPE2 Model and NLAM are similar and it is satisfactory result that the pressure distributions of the tab water design criterion of 5.0kgf/cm$^2$ besides the small part of highland.

• Human Ecology Research
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• 제61권2호
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• pp.263-280
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• 2023

This study examined four ecological systems, namely individual, family, school, and media environments. A series of moderator analyses were conducted to examine variations in effect size estimates across the study characteristics. The current study estimated that the effect size results were gleaned from 360 primary studies, including 90 journal articles and 270 thesis/dissertations, published between 2011 and 2022. The current meta-analysis results supported the ecological framework. That is, the impact of each ecological system on the development of positive and negative peer relationships varies depending on age groups and protective-risk factors. Specifically, for positive peer relationships, the largest effect size of the protective factor was found at the individual level for young and school- aged children, but at the school level for adolescents. Regarding the risk factors for positive peer relationships, the media was the ecological system with the strongest effect size for both young children and adolescents, while the individual-level demonstrating the strongest effect for school-aged children. Results from this meta-analysis allow us to identify some vital intervention areas in terms of healthy peer-relationship development, which should be of considerable interest to the educators and policymakers who are responsible for assessing and intervening with at-risk young children, school-aged children, and adolescents. From a practical standpoint, the current meta-analysis results are expected to contribute to developing effective prevention initiatives by targeting specific protective and risk factors for peer relationship development on the ecological system level.