• 한국항공우주학회지
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• 제46권6호
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• pp.513-518
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• 2018

KUH-1에 적용되는 질소충전트레일러는 항공기의 주/전륜 완충기, 테일범퍼완충기, 브레이크 축압기, 타이어 등에 질소를 충전하는 장비이다. 명칭에서 알 수 있는 것과 같이 질소충전트레일러는 질소 충전과 더불어 이동성을 가지고 있는 장비이다. 기존 미국의 Tronair사에서 독점 공급하여 국내에서는 수입에 의존하던 품목이며, 본 국산화 개발품은 도입품의 성능을 만족할 뿐만 아니라 운용 시 도입품보다 용이하도록 설계를 추진하였다. 제15-4차 민관공동투자사업으로 선정되어 개발이 진행되었으며, 민관투자기업인 한국항공우주산업과 국방기술품질원의 개발관리 지원하에 개발요구도 분석 및 시험평가가 수행되었으며, 2017년 5월 군사용 적합 판정 결과 승인을 받았다.

• 한국산업융합학회 논문집
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• 제23권3호
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• pp.445-452
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• 2020

The air cleaning unit of K00 IFV(or Infantry Fighting Vehicle) has important roles to make sure the engine of the vehicle works precisely as filtering foreign substances in the air such as dust and sands. The entire components including scavenge fan which is one of the important inner part of the air cleaning unit are developed so that we can produce it domestically and don't need to import it from P^⁎⁎ Co., the original maker in United Kingdom. This paper introduces a few verification processes including cleaning efficiency and reliability. As this core unit has developed successfully the improvement of military strength and logistics support can be expected. And design capability, manufacturing skills, maintenance ability of tracked weapon system will be increased thanks to the accumulated technical knowledge obtained from this developing project. Foreign currency savings and reducing operational cost can be expected as well in military industry.

• 산업경영시스템학회지
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• 제35권1호
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• pp.198-213
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• 2012

Navy ship acquisition management business contributed to the korean Navy and defense exports with government suppliers in Korea for over 40 years. But due to advanced technology, development trend of Navy ship and defense export requirements, it enable to make a contribution to a better system improvement are being demanded. In this paper, an adjective Navy ship acquisition process is presented in order to improve the acquisition process takes the first step for acquisition planning process to enhance the efficiency and rationality that is based on consensus of Navy ship expert and experienced. In addition, systems engineering (SE) and quality control (QC) techniques based on Modeling and Simulation are investigated to carry out efficient project management and scientific quality control system in Navy ship acquisition process. Finally, it is suggested to apply SE/QC based on M&S for Navy ship acquisition process using civilian infrastructure and organizations in order to take advantage of the world's leading domestic industry based on considering the difficult conditions of Navy ship suppliers.

• 한국경영과학회지
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• 제37권2호
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• pp.73-88
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• 2012

Even though the final source selection of foreign weapon system purchase project in defense area is the most important phase, the standard evaluation index has not been developed. This paper provides an appropriate evaluation index using DEMATEL and ANP methods. First, the all possible evaluation criteria applied to the relevant previous literatures in domestic and overseas researches are derived and classified into groups. Second, DEMATEL method is used to determine the network structure representing the relations of cause and effect between groups and their sub-criteria. If isolated factors, not connected with other factors, are existed in the network structure, all factors except for the isolated ones are grouped as one large factor so that the independency between those ones is maintained. The weights of criteria are determined using AHP method if the criteria are independent relation and ANP method if the criteria are networked. The weights of higher and lower level criteria are then integrated and distributed as a point with respect to the decision making purpose. The developed evaluation index can be used as a standard one in various foreign weapon system purchase projects in defense area.

• 한국국방경영분석학회지
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• 제31권2호
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• pp.86-104
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• 2005

During the 'Cold War', DoD had focused on the high performance and timely acquisition which enabled quick field out the superior weapons than the enemy regardless of acquisition cost. But, after the cold war, the focus has been changed to the 'cost effective acquisition' of weapon systems because of tremendous investment cost & economic theory. The U.S. DoD has been tried to make 'the most effective acquisition system'(AR, Acquisition Reform) from mid-80's with their enough experienced program data, and as a result, they had launched the new acquisition procedure - DoD 5000 series - in 1996. DoD is continuously doing the study and making several improvements on the procedure after it had been once announced. On Oct 30. 2002, DoD noticed that they cancelled the DoD 5000 series documents(5000.1, 5000.2, 5000.2-R) and 5000.2-R will be reissued as a guide. The most recent version which focused on 1) evolutionary acquisition and spiral development, 2) procedure for future technology systems including software and IT, 3) supplement on the area of efficiency, flexibility, creativity and innovation of old system was issued by May 12. 2003. This article suggests a 'good idea' based on the reviewing of these DoD efforts for our defense acquisition regulation and procedure to go. It includes the CAIV concept application, IPT utilization, T&E method, cost or price based contract etc-all for the effective acquisition.

• Geomechanics and Engineering
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• 제38권5호
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• pp.507-515
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• 2024

An accurate estimation of the geotechnical parameters in front of tunnel faces is crucial for the safe construction of underground infrastructure using tunnel boring machines (TBMs). This study was aimed at developing a data-driven model for predicting the rock quality designation (RQD) of the ground formation ahead of tunnel faces. The dataset used for the machine learning (ML) model comprises seven geological and mechanical features and 564 RQD values, obtained from an earth pressure balance (EPB) shield TBM tunneling project beneath the Han River in the Republic of Korea. Four ML algorithms were employed in developing the RQD prediction model: k-nearest neighbor (KNN), support vector regression (SVR), random forest (RF), and extreme gradient boosting (XGB). The grid search and five-fold cross-validation techniques were applied to optimize the prediction performance of the developed model by identifying the optimal hyperparameter combinations. The prediction results revealed that the RF algorithm-based model exhibited superior performance, achieving a root mean square error of 7.38% and coefficient of determination of 0.81. In addition, the Shapley additive explanations (SHAP) approach was adopted to determine the most relevant features, thereby enhancing the interpretability and reliability of the developed model with the RF algorithm. It was concluded that the developed model can successfully predict the RQD of the ground formation ahead of tunnel faces, contributing to safe and efficient tunnel excavation.

• 한국산학기술학회논문지
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• 제21권6호
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• pp.70-77
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• 2020

형상관리(configuration management)는 중요한 사업관리 방법의 하나이다. 국방 분야에서도 형상관리는 방위력 개선뿐만 아니라 전력지원 체계의 기술자료에 대한 관리도구로 그 중요성이 날로 증대되고 있다. 우수한 무기체계의 획득을 위하여 개발초기부터 형상관리 업무를 제대로 수행하는 것이 필요하다. 군수품 획득에 있어서 형상에 대한 관리는 군수품 전 수명주기 동안의 운영유지 비용을 결정하고 운영지원 간 체계적인 관리를 실시할 수 있는 중요한 요소이다. 세계 각국은 연구개발과 표준, 특허를 연구수행 초기부터 상호 연계하여 관리하도록 정책과 제도의 변화를 기하고 있으며, 우리 또한 군수 자원의 효율적 관리 수단으로써 형상에 대한 관리 및 통제의 개념 정립 및 업무 체계 구축이 필요한 실정이다. 군수품 형상통제(configuration control)를 총 수명주기와 연계하여 획득 초기부터 폐기까지의 전 수명주기 동안의 활동 내역을 식별하고 이에 맞는 업무 절차 및 체계를 재정립하기 위해, 본 논문에서는 미국의 형상통제 업무 절차를 조사 및 분석하여 활동 내역을 식별하고 향후 발전시켜야 할 부분을 제시하였다.

• 대한용접접합학회:학술대회논문집
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• 대한용접접합학회 2009년 추계학술발표대회
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• pp.40-40
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• 2009

The Cu-bearing PFS-700 steel which has yield strength over 700 MPa was developed to replace the existing submarine structural material, HY-100. PFS-700 steel has good combination of mechanical properties and superior weldability which can be welded without pre-heating before welding. Application PFS-700 steel to submarine or battle ship will give a great reduction of cost by removing or lowing pre-heating. To develop pre-heat free welding consumables that matches and take advantage of PFS-700 steel, new welding consumables have been designed for the GMAW, SAW processes and explosion bulge test(EBT) were conducted to see the reliability of welded structure. All welding was conducted without pre-heating before welding, the inter-pass temperatures were below $50^{\circ}C$ for SAW50 and $150^{\circ}C$ for GMAW and SAW150. All EBT specimens show over 14% reduction of thickness without through-thickness crack or propagation of crack to the hole-down area. Tensile properties for all welding conditions show higher(GMAW) or similar values(SAW50, SAW150) to the base metal. Charpy impact values for the weld metal also show 163.5J(GMAW), 95.4J(SAW50) and 69.0J(SAW150), which meet the goal, 50J, of this project.

• 농촌계획
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• 제22권2호
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• pp.67-75
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• 2016

This Research was carried out to investigate landscape characteristics of the traditional Chinese village through the landscape analysis. The Purpose of this study was to offer suggestions for improving Korea's traditional village scenery. This research was conducted by analysis about an important component of the landscape in Ping-shan traditional village. It was studied natural landscape, life landscapes, agricultural production landscapes and symbols landscape. This study was carried out through literature research, field research and interviews. The results of Chinese traditional village's landscape characteristic was First, Ping-shan traditional village was located on the basis of Feng-Shui settings. Second, Ping-shan traditional village was clan-based. Third, It is composed of a large green space on the outskirts of the village. Fourth, Ping-shan traditional village was a typical channel village. Fifth, Ping-shan traditional village was a living landscape with various features. sixth, Ping-shan traditional village was a lot of space to agricultural production, most of the arable land surround village. Suggestions for improving Korea's traditional village scenery are as follows ; First, proposes actively re-design on the base of defense fengshi landscape interpreted as a modern sense. Seconds, when large-scale farmland project is established in Korea, you can expect to gain knowledge from traditional Chinese village spacing. Thirds, It seems to require a study of the public space for festival. in the case of china, ancestral shrine space is center and space for festival. Fourth, It was important to seek knowledge about protection for frequent in flood plains in Korea's traditional village. Ping-shan traditional village was well-known for housing with contact water, connected channels and beautiful defense pond. Fifth, for improving Korea's traditional village scenery, we need to make various focus landscape features. Most of the visitors to Ping-shan traditional village was interested in the big and small beautiful landscapes and shelters.

• Journal of Welding and Joining
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• 제27권6호
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• pp.80-86
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• 2009

The Cu-bearing PFS-700 steel which has yield strength over 700 MPa was developed to replace the existing submarine structural material, HY-100. The PFS-700 steel has a combination of good mechanical properties and superior weldability. Becaus of that, it can be welded without pre-heating. The application of PFS-700 steel to submarine or battle ship will give a great reduction of cost by omitting pre-heating or lowering pre-heat temperature. To develop pre-heating free welding consumables that match and take advantage of PFS-700 steel, new welding consumables have been designed for the GMAW, SAW processes and explosion bulge test(EBT) was conducted to see the reliability of welded structure. All welds were made without pre-heating, and the inter-pass temperature was below $50^{\circ}C$ for SAW50 and $150^{\circ}C$ for GMAW and SAW150. All EBT specimens show over 14% thickness reduction without through-thickness crack or crack propagation to the hole-down area. Tensile properties for all welding conditions show higher(GMAW) or similar values(SAW50, SAW150) to the base metal. Charpy impact values for the weld metal also show 163.5J(GMAW), 95.4J(SAW50) and 69.0J(SAW150), which meet the goal(higher than 50J) of this project.