군용헬기 결빙 감항인증을 위한 국내 기상환경에 관한 연구

허장욱,신백천,Hur, Jangwook,Shin, Baekcheon 한국군사과학기술학회 2014 한국군사과학기술학회지 Vol.17 No.3

Based on atmosphere weather data by balloon in Osan and Gwangju area, if icing condition occurs in weather environment of altitude range where helicopter is operated was analyzed in quantitative way. Yearly icing occurrence frequency for daytime during recent three years was average 102 days in Osan, average 91 days in Gwangju. Icing weather environment to highly affect operation of helicopter varies a little according to analysis methods but icing intensity at MDT level was calculated in all the methods, and 14.5~38 times was suggested in Osan; 2.5~30 times in Gwangju. Icing at MDT level was calculated in common in all the analysis methods through wide periods such as Jan., Feb., Mar., and Nov. in Osan. In Gwangju, icing at MDT level was suggested focusing on Jan. only. Therefore, military helicopter developed in Korea is required to strive obtaining certificate of airworthiness about icing condition at MDT level for implementation of perfect operational mission and safe operation.

국방규격 적합성 검토체계 개선에 대한 고찰

김성경,허장욱,Kim, Sungkyung,Hur, Jangwook 한국군사과학기술학회 2016 한국군사과학기술학회지 Vol.19 No.5

Defense specification suitability review task means to examine whether to need enactment, amendment or abolition of defense specification, and realistic and efficient review environment are urgently needed by improving system. For the promotion of efficient tasks, the cycle of defense specification suitability review needs to be changed to 5 years for active specifications and 10 years for inactive specifications. To simplify the standards of defense specification suitability review, the distinction between prior management items and general management items should be abolished and the number of review items need to be reduced from ten to three. Also, in order to promote substantial defense specification suitability review, a system improvement is needed to utilize retired professionals from defense acquisition related agencies.

무기체계 업체주관 연구개발 사업의 개발시험평가 개선방안 고찰

김성경,김찬동,허장욱,Kim, Sungkyung,Kim, Chandong,HUR, Jangwook 한국군사과학기술학회 2015 한국군사과학기술학회지 Vol.18 No.6

The improvement of the reliability of weapon systems and the reduction of the total life-cycle cost based on the improving of the DT&E system for Company Organized weapon systems research and development are urgently required. The major advanced countries operate test and evaluation centers for military (U.S.), manage a large scale organization of IPT personnel (England) or conduct management of DT&E through a third party organization (France). Based on a survey of experts, an improvement of the DT&E policy in terms of reliability and objectiveness is needed, and management through a third party national defense agency and civilian agency such as the Surion development case is required. In addition, although it appears that efficiency improves when management of DT&E is performed by national defence agencies rather than civilian agencies, it is necessary to proceed by selecting a civilian agency based on competition in the case that it is difficult to select a national defence agency.

OPUS Suite를 이용한 RAM-C 분석도구의 검증

김한솔(Hansol Kim),허장욱(Jangwook Hur) 한국신뢰성학회 2020 신뢰성응용연구 Vol.20 No.1

Purpose: Markov Process Simulator (MPS) is a RAM-C analysis program. its optimal design alternative decision, which is achieved by analyzing the effect of RAM parameters on the life cycle cost using the Markov-Monte Carlo technique, needs to be verified. Methods: The OPUS Suite of Systecon, an advanced program used by defense companies to verify the program, is used to model the communication and identification system of helicopters as well as to calculate the failure number, operation availability and life cycle cost among the output values of the MPS and OPUS Suite. Results: When comparing the results of the MPS and OPUS Suite, the number of failures was less than one, the error of operation availability was 1.6%, and the life cycle cost error was 3.9%. Conclusion: The results of the MPS analysis showed a very small error compared to the results of the OPUS Suite, which is widely used in the defense field of major developed countries as well as Korea and verified the validity of the MPS.

무기체계의 상세 설계단계 정비도 예측을 위한 FD&I 산출방안 연구

김수주(Suju Kim),허장욱(Jangwook Hur) 한국신뢰성학회 2020 신뢰성응용연구 Vol.20 No.1

Purpose: This study investigated MIL-HDBK-472 Procedure V and suggests the method for deriving FD&I, a key parameter for applying Method B. The study also describes the process for calculating the mean time repair (MTTR) of the system by applying Method B. Methods: Of the maintenance procedures Procedure I-V presented in MIL-HDBK-472, Procedure V is divided into Method A and Method B as applicable at all stages of maintenance, and FD&I elicitation is essential for applying Method B in the detailed design phase. Results: The FD&I elicitation process was presented, and the MTTR value was applied with Method A considering an ambiguous factor(S) called the ability to isolate faults during the initial design phase was compared by the MTTR value applied with Method B. Conclusion: In order to predict the degree of maintenance at the detailed design stage during system development, Method B of the Procedure V used by the U.S. military is required, it is possible to improve the predictive accuracy of maintainability through comparison with Method A when it is applied in the initial design phase.

무기체계 RAM 목표값 설정 관련 개선방안 고찰

황경환(Kyeong Hwan Hwang),허장욱(Jangwook Hur) 한국신뢰성학회 2017 신뢰성응용연구 Vol.17 No.2

Purpose: The RAM objective is a very important factor that has a great effect on the improvement of the operation ration during the operation maintenance and the reduction of the life cycle cost. It is used as a design criterion during the system development, and its sufficiency should be evaluated during its test evaluation. Method: This study analyzed the cases related to RAM objective setting and suggested the improvement measures. Result: The base data for RAM objective is OMS/MP, which needs to be drawn up under the supervision of the requirement military, and a high-accuracy operating availability should be set through ALDT calculation which reflects the military logistics support environment. In addition, data collection necessary for RAM objective and RAM analysis should be made by supplementing the input data of DELIIS. Conclusion: This study suggests improvement of RAM objective considering for the weapon system.

유도탄의 신뢰성 향상 방안 고찰

김보현(Bohyeon Kim),황경환(Kyeonghwan Hwang),허장욱(Jangwook Hur) 한국신뢰성학회 2016 신뢰성응용연구 Vol.16 No.3

Purpose: ASRP for the domestic development guided missiles requires not only for the reliability evaluation of the products in storage but also for the life cycle management of the products including development prototypes and initial production items. Methods: For this purpose, it should be performed to build a performance database before and after the accelerated aging test with shelf life items including development prototypes and initial production items, based on which the lifetime prediction should also be carried out. In addition, HILS must be applied for the acceptance test with the initial and follow-up production items, and also for ASRP for the long-term storage products in order to secure systematic quality assurance. Results: The results for the life cycle reliability Improving of domestic development of guided missiles are DB building of prescription Item performance, active application of HILS, Management associated with guided missiles life cycle and to Secure technology data about the introduction of foreign guided missiles. Conclusion: Furthermore, it is demanded that DTaQ, the managing agency of ASRP, actively take part in the process to maintain reliability engagement consistency over the life cycle of guided missiles.

Development Direction of Reliability-based ROK Amphibious Assault Vehicles

Ilho Baek(백일호),Jusung Bong(봉주성),Jangwook Hur(허장욱) 한국기계가공학회 2021 한국기계가공학회지 Vol.20 No.2

A plan for the development of reliability-based ROK amphibious assault vehicles is proposed. By analyzing the development case of the U.S. EFV, considerations for the successful development of the next-generation Korea Forces amphibious assault vehicle are presented. If the vehicle reliability can be improved to the level of the fourth highest priority electric unit for power units, suspensions, decelerators, and body groups, which have the highest priority among fault frequency items, a system level MTBF of 36.4%↑ can be achieved, and the operational availability can be increased by 3.5%↑. The next-generation amphibious assault vehicles must fulfill certain operating and performance requirements, the underlying systems must be built, and sequencing of the hybrid engine and the modular concept should be considered. Along with big-data- and machine-learning-based failure prediction, machine maintenance based on augmented reality/virtual reality and remote maintenance should be used to improve the ability to maintain combat readiness and reduce lifecycle costs.

블래더와 하우징으로 구성된 축압기의 수명피로예측

김대유(Daeyu Kim),이건희(Geonhee Lee),허장욱(Jangwook Hur) 한국기계가공학회 2018 한국기계가공학회지 Vol.17 No.5

Recently in weapon systems development, the importance of reliability has been emphasized due to the increase in complexity and the rapid development of key components and components. Accordingly, the importance of lifespan testing is increased. However, lifespan testing to verify the reliability of a system is costly and takes a lot of time. Therefore in this paper, it was demonstrated that the most critical item of a bladder type accumulator is the bladder. Fatigue life is sensitive to temperature and pressure, with temperature having more impact. The fatigue life of the bladder was estimated to be 18,140 hr through fatigue analysis, which satisfies the required life expectancy of 10,000 hr.

무기체계 신뢰성 향상을 위한 중소 방산업체 환경시험 지원방안 고찰

황경환(Kyunghwan Hwang),김보현(Bohyeon Kim),허장욱(Jangwook Hur) 한국신뢰성학회 2016 신뢰성응용연구 Vol.16 No.4

Purpose: Environment test support is urgent for small and medium defense companies in order to improve the reliability of weapons systems. Also, to reduce the burden of test costs, the voucher system must be strengthened. Quality assurance support should be accompanied by budget support. Methods: First of all, it is necessary to expand infrastructure for test equipment that suffers shortages by considering environmental test frequency and waiting periods to reduce the time required for environmental tests. Results: In regard to the environmental test, expansion for test equipment infrastructure, security of budget for the test, establishment of test plan, education and consulting support are required to resolve some limits of small and medium defense companies. Conclusion: Along with the opening of environmental test courses for industry operators, the expansion for consulting support projects of the defense industry support system is needed.