• 한국도로학회논문집
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• 제16권4호
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• pp.75-86
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• 2014

PURPOSES: The aim of this paper is developing user-oriented flexible Level Of Service (LOS) system for integrated asset management of various road facilities. It is essential to overcome limitations of general management systems which only focus on a type of assets (e.g. pavement, bridge etc.), and to serve a customizable LOS platform for smooth implementation and future improvement of the LOS considering various managerial environments of road agencies. METHODS: This study suggested a total framework of the LOS system as a process for self-development, operation and improvement of LOS system to conduct the PDCA (Plan-Do-Check-Act) in management process. In the process, we adopted user-customizable elements regarding asset definition, service index and evaluation method to match with the managerial environment of road agencies. In addition, we conducted an empirical study on the entire process of the suggested LOS system with a real road agency (Korea Express Highway) to prove applicability of the LOS system. RESULTS: From the empirical study, we confirmed that the suggested LOS system framework were suitable for development of customized LOS system. In addition, evaluation of asset conditions by LOS ratings, and quantification of vision achievement of the Korea Express Highway were successfully made. It would be the first trial in integrated management approach with LOS systems for numerous road facilities. CONCLUSIONS : It was recognized that easy application and sustainable improvement of the LOS was the most critical point in asset management. The suggested LOS system would be a powerful weapon as a managerial tool in preparing tight budget, aging infrastructures, and increased demands for more accountability both in Korea and internationally. Implementation of the LOS system needs to be expanded to the other infrastructure members to serve satisfactory level of service to taxpayers.

• 한국추진공학회지
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• 제18권3호
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• pp.70-77
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• 2014

본 논문은 한국형 2.75 인치 로켓 추진기관의 독자 모델 개발에 관하여 기술하였다. 개발된 한국형 2.75 인치 로켓 추진기관은 추진제 그레인의 형상변경을 통하여 화염안정성을 증대시켰으며, 점화장치에 EMI 필터를 장착하여 우발점화 방지기능을 추가하였다. 그리고 노즐 형상 변경 및 날개 수 증가를 통하여 비행안정성의 향상을 가질 수 있었다. 지상연소시험 및 온도충격시험을 통해 추진제의 성능을 검증하였으며, 약 210 발의 비행시험을 통해 기 배치된 추진기관과 비행성능이 동일함을 입증하였다. 성능개량과 더불어 한국형 독자모델 개발로 인한 지적재산권 문제 극복에 기여할 수 있는 근간을 마련했다는데 그 의의가 있다.

• 대한조선학회논문집
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• 제46권3호
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• pp.313-314
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• 2009

To project military power, the paradigm of the modern warship aquisition has evolved with more large platform and high-technology equipment. For example, the Aegis combat system equipped warship is one of the most advanced and capable defense systems currently in use. Concurrently, if the warship attacked and disabled, it may worse the asymmetry of the battle field and it also depress the morale of the fleet. For that reason, to keep and protect few number of the big and high technology equipped warship from enemy is very important. At the present, the performance of unit weapon has enhanced remarkably. A Korean-built SS-209 class submarine, Lee Chun-ham, participated in Naval Exercise Tandem Thrust conducted in 1999, sink the target ship ex-USS Oklahoma by a single torpedo. USS Stark was struck on May 17, 1987, by two Exocet anti ship missiles and disabled. For this reason, susceptibility should be prior to vulnerability and recoverability. In this paper, deception ship which is small and chief but has very similar signatures to large and high technology equiped warship has conceptually studied by using systems engineering approach. And it may be a effective way to enhance the susceptibility of the key fighting power.

• 산업경영시스템학회지
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• 제40권4호
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• pp.246-252
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• 2017

In the defense acquisition, a company's goal is to maximize profits, and the government's goal is to allocate budgets efficiently. Each year, the government estimates the ratio of indirect cost sector to defense companies, and estimates the ratio to be applied when calculating cost of the defense articles next year. The defense industry environment is changing rapidly, due to the increasing trend of defense acquisition budgets, the advancement of weapon systems, the effects of the 4th industrial revolution, and so on. As a result, the cost structure of defense companies is being diversifying. The purpose of this study is to find an alternative that can enhance the rationality of the current methodology for estimating the ratio of indirect cost sector of defense companies. To do this, we conducted data analysis using the R language on the cost data of defense companies over the past six years in the Defense Integrated Cost System. First, cluster analysis was conducted on the cost characteristics of defense companies. Then, we conducted a regression analysis of the relationship between direct and indirect costs for each cluster to see how much it reflects the cost structure of defense companies in direct labor cost-based indirect cost rate estimates. Lastly a new ratio prediction model based on regularized regression analysis was developed, applied to each cluster, and analyzed to compare performance with existing prediction models. According to the results of the study, it is necessary to estimate the indirect cost ratio based on the cost character group of defense companies, and the direct labor cost based indirect cost ratio estimation partially reflects the cost structure of defense companies. In addition, the current indirect cost ratio prediction method has a larger error than the new model.

• 한국국방경영분석학회지
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• 제35권2호
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• pp.15-31
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• 2009

본 논문은 방위사업청 개칭이후 국방획득체계 운영과정에서 드러난 몇 가지 비효율적인 문제점을 분석하고, 이를 개선하는데 필요한 방안을 모색하는데 있다. 이것은 앞으로 국방부가 획득체계를 개선할 시 참고자료로 활용하는데 도움을 줄 수 있을 것이다. 제시된 방안들은 첫째, 국방부와 방위사업청간 중기계획 및 예산편성에 관한 기능을 재정립해야 한다. 둘째,소요-획득-운영유지의 통합관리체계 구축을 통해 경제적 획득관리 및 전력발전을 도모해야 한다. 셋째, 소요-획득분야 인력순환(순환근무)을 제도화하고, 획득인력의 전문성 강화를 위해 인력관리법 및 전문교육체계를 구축해야 한다. 그리고 넷째, 무기체계 '총수명주기체계관리'를 시행하고, 방위사업청 주도의 개발 및 운용시험평가 방식을 개선해야 한다. 이것은 국방부-방위사업청-각 군 간 획득사업을 둘러싸고 파생되는 업무혼선과 갈등을 최소화하는데 있어 필수적인 요소들이다.

• 융합보안논문지
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• 제14권1호
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• pp.11-21
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• 2014

한국은 과거처럼 국제관계의 예속자가 아니라 명실상부한 중견국으로서, 북한의 핵과 재래전 도발위협을 극복하고 동북아지역의 평화를 유지하는 '균형자' 역할을 할 수 있도록 군사력을 건설해야 한다. 군사력 건설을 통해 다양한 안보위협에 대한 억제력 발휘가 가능하다. 군사적 억제력 발휘를 위해 첫 번째로 '선제적 억제'(deterrence by preemptive)와 '응징적 억제'(deterrence by punishment)는 현재와 미래의 위협에 대비하여 '감시정찰체계와 지휘통제체계'(C41SR)를 공통전력으로 공격무기체계를 결합한 '공격체계 축'을 건설함으로써 달성할 수 있다. 두 번째로 '거부적 억제'(deterrence by denial)는 공통전력과 방어무기체계를 결합한 '방어체계 축'을 건설함으로써 달성할 수 있다. 마지막으로 자주적으로 첨단전력을 개발하기 위해서는 기존의 방위산업과 연구개발 역량을 통합하여 '인프라 축'을 구축해야 한다. 우리는 미래 한국군의 군사력을 건설함에 있어서 정부의 균형자 역할에 대한 국가적 비젼, 이에 대한 국민적 합의를 토대로 본고에서 제시한 군사력 건설 모형에 따른 일관성 있는 정책적인 노력과 신념이 반드시 필요하다.

• 시스템엔지니어링학술지
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• 제4권1호
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• pp.35-43
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• 2008

Generally, in analysis of reliability of Design and Development Phase, reliability of electrical components is analyzed based on standards such as MIL-HDBK-217F, Bellcore Issue 4,5,6 by analyzing stress of architectural side (Power, Voltage, Current and quality level of components) of weapon system and stress of operational side (operational environment, operational temperature, Operational Profile). But the reliability of mechanical components is analyzed based on the data book of failure history of mechanical parts called NPRD-95(Nonelectronic Parts Reliability Data-95) without any analysis of above stress. However, even if it's the same mechanical parts, it might have different failure rate(fatigue, wear, corrosion) during operation depending on how weary(stress : pressure, vibration, temperature during operation) the parts are. Therefore, analyzing reliability using just data book can cause big difference in reliability instead of analyzing based upon stressfulness that parts might have, operational concept, and other various factors. Thus, This paper will guide the way of predicting reliability by organizing ways of predicting reliability for system organization and adopt ing NSWC-98/LE1(Naval Surface Warfare Center-98/LE1) for mechanical components.

• 산업경영시스템학회지
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• 제42권3호
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• pp.89-94
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• 2019

K1A1 tank commander's primary thermal sight is a device that enables tank commanders to detect, identify, aim and track the target by observing targets in all directions during day, night and in situations of smokescreen and fog through $360^{\circ}$ rotation independent from the gunner's primary thermal sight and stabilizing the line of sight even under the vibrations occurring when the tank is standstill and moving. The main function of this device is to detect and process visible and thermal images and deliver the final images to the tank commander. One of the core parts to that end is the observation window (daytime/thermal image window). This core part is mounted at the entrance of the optical path for observing the target and plays the role of making visible light during the daytime and infrared light during the night pass through the target and transmitting the resultant images to the internal optical system of the tank commander's primary thermal sight. Such core parts have been selected as depot maintenance items so that they are replaced by new parts instead of being recycled when they are subjected to maintenance in most cases. That is, the military budget is wasted because such parts are replaced by new parts despite that they can be recycled for maintenance. Therefore, this study proposed a mounting tool for polishing and coating observation windows (daytime and thermal image window) using planar polishing equipment and DLC (Diamond-Like Carbon) coating equipment. In addition, this study presented an amendment (proposal) of the Depot Maintenance Work Request (DMWR) already published to verify the performance of recycled products including the establishment of inspection standards for recycling processes.

• 산업경영시스템학회지
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• 제44권1호
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• pp.26-36
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• 2021

The topic of this study is the field of humanitarian logistics for disaster response. Many existing studies have revealed that compliance with the golden time in response to a disaster determines the success or failure of relief activities, and logistics costs account for 80% of the disaster response cost. Besides, the agility, responsiveness, and effectiveness of the humanitarian logistics system are emphasized in consideration of the disaster situation's characteristics, such as the urgency of life-saving and rapid environmental changes. In other words, they emphasize the importance of logistics activities in disaster response, which includes the effective and efficient distribution of relief supplies. This study proposes a mathematical model for establishing a transport plan to distribute relief supplies in a disaster situation. To determine vehicles' route and the amount of relief for cities suffering a disaster, it mainly considers the urgency, effectiveness (restoration rate), and uncertainty in the logistics system. The model is initially developed as a mixed-integer nonlinear programming (MINLP) model containing some nonlinear functions and transform into a Mixed-integer linear programming (MILP) model using a logarithmic transformation and piecewise linear approximation method. Furthermore, a minimax problem is suggested to search for breakpoints and slopes to define a piecewise linear function that minimizes the linear approximation error. A numerical experiment is performed to verify the MILP model, and linear approximation error is also analyzed in the experiment.

• 시스템엔지니어링학술지
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• 제18권2호
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• pp.108-116
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• 2022

Accurately predicting wartime resources requirements and preparing war supplies in peacetime is an important task that can determine the outcome of the war by guaranteeing the duration of the operation. The wartime warship damage rate is a measure of estimating the battle damage of our warships in the process of performing battles to achieve the war goal. In the previously studied wartime warship damage rate estimation method, when damage occurs, long-term repair is required due to the complexity and specificity of the ship structure. Only the case of a complete defeat at the level of sinking was defined as a damage, and even if it was impossible to perform a maritime operation mission, it was not estimated as a damage if the level of sinking was not reached. Therefore, in order to improve the reliability of the wartime warship damage rate, the equipment damage assessment level can be estimated based on the warhead weight of the threat weapon system, the vulnerability rate of the warship's equipment, and the warship's hull. In the future, it is expected that the estimation methodology proposed in this study will be used as a simulation logic when developing a model for analyzing the wartime resources requirements for the warship's equipment and hull.