• Journal of Korean Society for Quality Management
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• v.43 no.3
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• pp.273-288
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• 2015

Purpose: In this study, we apply environmental stress screening (ESS) to battle management system (BMS) of a tank and use the ESS profile based on production process data, guided by MIL-HDBK-781/344/2164. Methods: To optimize ESS Profile of the BMS of a tank, we estimate ESS model parameters (e.g., defect density, screening strength) using primary production failure reporting and corrective action system (FRACAS) data of military supply contract firm. Results: First, we collect the Primary production FRACAS data of military supply contract firm. Second, we compute curve fitting approach to find patent defect density and latent defect density using FRACAS data. Third, we solve the equation of Defect Density(patent defect density + latent defect density)($D_{IN}$) and Screening Strength(SS) Using second step data. As a result of analysis according to the order, we calculate $D_{IN}$(Temperature stress case : 74.02, Vibration stress : 10.252) and : SS(Temperature stress case : 0.4632, Vibration stress : 0.4142) and confirm the Condition II-D based on MIL-HDBK-344. According to Condition II-D, it is necessary to modify existing ESS profile through decreasing the $D_{IN}$ and increasing the SS. Conclusion: Identification of defect causes through ESS approach reduce defect densities for production. It provides feedback to a lessons-learned data base to avoid similar problems on next generation tank BMS.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.41 no.4
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• pp.160-170
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• 2018

This paper is an exploratory study on the success factors of Defence Quality Management System (DQMS) which is the certification system granted by the military for improving the quality of munitions. DQMS is established by adding military requirements to the ISO standard, thus, we especially focus on the additional requirements to figure out success key factors of DQMS certification. The 51 additional requirements of Korean Defense Specification (KDS) are empirically investigated from 67 companies that acquired DQMS certification. Firstly, we conduct an independent t-tests on 51 additional requirements of KDS 0050-900-3 to determine if there is a difference between an easily certified company and a hard-to-certify company, and obtain 8 requirements such as 'Internal propagation of performance', 'Preparation of documented work instructions', 'Work instructions in the workplace', 'Documentation of equipment management', 'Inventory management', 'Packaging and identification', 'Guarantee of access to internal audit result for customers', 'Notification to the customer for improper product.' Secondly, we carry out an factor analysis to the 51 additional requirements for classification, and figure out that 4 requirements among the 8 requirements above mentioned are grouped together in the same factor. The 4 requirements are 'Preparation of documented work instructions', 'Work instructions in the workplace', 'Packaging and identification', and 'Guarantee of access to internal audit result for customers.' The result of this paper will provide useful information to the company preparing for DQMS.

• Journal of Applied Reliability
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• v.17 no.2
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• pp.83-91
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• 2017

Purpose: The purpose of this study is to develop a quality assurance model and to determine appropriate warranty period for a guided missile using its field data. Methods: 10 years of actual firing data is collected from the defense industry company and military. Parametric maximum likelihood estimation for a reliability function is determined with the data. Results: The reliability function estimates average lifetime of the missile. That function shows a user requirement, 80% reliability (lifetime) is come up when 8 years have passed, which is longer than the estimates in the missile's development phase. Conclusion: Quality assurance warranty for a guided missile must be established with actual test data. It is necessary to update and modify the reliability prediction and the warranty period with actual field test data.

• Journal of Aerospace System Engineering
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• v.13 no.1
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• pp.62-68
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• 2019

The software installed on an aircraft is directly related to its safety. Therefore, it shall comply with the standards of the airworthiness certification to ensure safety of flight. Airborne software should be developed in accordance with the DO-178 (Software Consideration in Airborne Systems and Equipment Certification) to comply with the airworthiness certification criterion. However, the military airborne software has been developed in accordance with the DAPA weapons system software development and management manual. In this paper, we completed a questionnaire survey of software experts. We also suggest a military airborne software development/certification process based on DO-178.

• Information Systems Review
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• v.18 no.1
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• pp.79-103
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• 2016

The Korean Army has to construct a system that will enable it to cope immediately with the flexible military relationships in Northeast Asia by systematizing and improving the efficiency of operations. These improvements include building a smart and strong army, concentrating on cost-effective combat skills, maximizing the utilization of private resources, and establishing a military structure based on information and technology. Accordingly, this study proposes solutions to solve the problems affecting the success of outsourcing in the defense industry. Unlike outsourcing in other government ministries, outsourcing in the national defense sector may be unrealistic because this strategy is related to the renovation project of the Ministry of the National Defense. In general, the objective of outsourcing in the defense industry, similar to other businesses, is to improve efficiency and not to reduce troops and national defense budget. Several factors, such as identification and security guarantee, risk reduction, cost saving, quality improvement, the reliability of enterprise, and professional technology, are necessary to ensure outsourcing success in the national defense sector. In terms of effectiveness, the improvement in service quality significantly influences outsourcing success in the national defense sector. Eventually, the national defense forces must be strengthened to prevent the provocative actions of North Korea and other threats by improving identification, sense of national security, and quality unlike the current outsourcing of the government, as well as emulating German GEBB or PMC, which utilizes social capital.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.12 no.4
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• pp.1597-1602
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• 2011

To understand current status for the utilization of Korean military specifications(KDS) and other standards/specifications in munitions companies, we have surveyed 150 companies mainly related with electrical and electronic industry. Most of the companies have expected that the harmonization of KDS and KS would bring a positive effect on their business, especially from the point of quality control, productivity increase, the reduction of expenditure for standard management and so on. This survey result will help to build more user-friendly management system for KDS as well as KS.

• Journal of Korean Society for Quality Management
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• v.39 no.3
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• pp.412-421
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• 2011

In this paper, we introduce Quality of Service(QoS) analytic model of a distributed system that decentralizes the process nodes performing each task and communicates through a network for cooperation. The model advances a service reliability model of Dai et a1.(2003) by means of considering the processing time. The service is assumed to be provided by a centralized heterogeneous distributed system which is composed of some subsystems managed by a control center. The QoS is defined as the probability that a service is provided successfully in an allowed time, we consider the hardware/software reliability and the processing time which include program execution time, data transfer time. We derive the processing time distribution for a required service through convolution of corresponding probability density function. An application example is used to explain the procedure of computing quality of service.

• Journal of the Korea Society of Computer and Information
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• v.18 no.1
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• pp.111-121
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• 2013

In this paper, we propose a study on the technology level survey and analysis of problems for improving the defense IT survey. Existing in 2008 and 2009, were surveyed and the documents were distributed. It's managed on system. It was surveyed 86 technology but, the selection method and content was simple. we surveyed and interviewed to work-related parties for improving and analyzed management system and documents. So we derived improvements. we selected defense IT from various aspects. and commissioned survey for document review and technology level to about 130 experts. The technology level is composed of the best technology weapon states, technology gap, spread effect, technology achievement time and research & development method.. We finally selected 40 technology, and suggested results of the technology level survey.

• Journal of Korean Society for Quality Management
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• v.47 no.3
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• pp.437-451
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• 2019

Purpose: The purpose of this study is to improve the quality of the PGM system by improving the structure and production process of slip-ring rotary joint for radar. Methods: The improvement measures for each cause are established through failure analysis of broken items. Specifically, changing in the housing to improve the heating system. Changing the transportation method to prevent damage to equipment during transport. Changing work process of the attenuator ring to prevent damage. etc. Results: The results of this study are as follows; improving the heating system reduces heat generated by the attenuator by about 7 degrees and obtain additional temperature margins. Reduction of defect rate because of adding X-band rotary joint run-out measurement test, ESS of slip-ring rotary joint and Transportation improvement(reinforced flight boxes, tube protection, etc). Getting stable VSWR values by improving work process of attenuator overheating due to a bad bonding process. Conclusion: Through this study, improvements were made to slip-ring rotary joint that failed repeatedly for various reasons. As a result of the application of the improvements, the same fault does not occur until now, so we can see that the quality of PGM has improved.

• Journal of Korean Society for Quality Management
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• v.43 no.3
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• pp.327-340
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• 2015

Purpose : Recently, many quality issues are aroused in military forces, such as failures in K-series weapons, combat uniforms' defects and 40mm ammunition explosion accident. To address these problems, Defense Agency for Technology and Quality(DTaQ) introduced new systems such as Manufacturing Readiness Assessment(MRA), Test Report Information System(TRIS) and so on. However, these activities require the human and time resources which cannot be increased in short period. In this paper, we suggest more practical and efficient product examination method. Methods : The most popular and widely used government's quality assurance technique is a sampling method to examine the product. In this research, we first reviewed the DTaQ's quality assurance regulation, then identified several possible problems and finally suggested more efficient and effective sampling plans. Results : We have suggested new sampling framework and evaluated its performance on two military supplies by comparing with other sampling method, and observed that the number of tested samples can be substantially reduced. Therefore, required quality assurance time can be saved. Conclusion : In this paper, we first reviewed the product examination frameworks of DTaQ, PPQMS and DCMA. Then we identified several possible problems which can cause the loss of objectivity and time. To handle these problems, we suggested the new product examination framework and tested the framework to verify the performance.