• 한국항행학회논문지
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• 제26권5호
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• pp.358-364
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• 2022

항공용 인터콤 시스템은 정/부조종사 간 내부 통화 및 조종사와 승무원 간 내부 통화, 초고주파 무전기(U/VHF)와 같은 통신 장비를 통한 외부 통화, 초단파전방향거리탐지기/계기착륙장치(VOR/ILS), 전술 항법 장치(TACAN)와 같은 항법 및 임무 장비 오디오 신호 모니터링, 비행 데이터기록장치(FDR) 및 자료전송 시스템(DTS)으로의 음성 녹음용 오디오 신호 출력, 항공기의 상태와 위협 등에 대한 오디오 경고음/경고 음성 발생 등 항공기 내의 모든 음성 신호에 대한 처리를 담당하는 장비이다. 이러한 항공용 인터콤은 아날로그 오디오 신호의 경우 노이즈에 민감하기 때문에 조종사 및 승무원의 임무 수행을 위해 항공기 내/외부의 전자파 노이즈로부터 오디오 신호를 보호할 수 있는 이중화 설계가 필요하다. 본 논문에서는 항공용 디지털 인터콤의 이중화를 위한 정상/백업 운용모드 및 디지털 방식의 이중화 설계 방안과 제작 및 검증 결과에 대하여 기술한다.

• 한국군사과학기술학회지
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• 제16권2호
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• pp.111-117
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• 2013

In this paper, we have proposed novel technique to improve maintainability for training vehicle of underwater weapon system. In case of under water weapon, the fire procedure is related with operation of expulsion system in submarines. So the submarine crews should practice the complex fire procedure of weapon system by using training vehicle, which is safer and cheaper than operational weapon. After emitted from submarine, the training vehicle rise to the surface and should be withdrawn from the sea. The recovered training vehicle is transported to maintenance depot and pass through the recycling procedure including disassembling the vehicle, data acquisition & analysis, battery charge, replacing expandable components, testing the captive equipment, and assembling the vehicle. The disassembling & assembling of training vehicle which is composed of watertight section or airframe, is time-consuming work. So in this paper, we have studied the elements of recycling procedure and propose the method to exclude the assembling & disassembling work for maintainability improvement.

• 한국안전학회지
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• 제28권2호
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• pp.73-77
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• 2013

Leisure activities alter overland tourism into marine tourism according to a rise in national income. It is expected that the leisure boat with period of introduction in marine tourism will be developed rapidly. It needs to unite with marine technology, optimized layout design, interior design and so on in order to build a yacht of high quality. Because optimized layout design and interior design technique increase the added value of the yacht, it needs to be convergence technology between Ergonomics, Sensibility Ergonomics, and design technique. In this study, we analyzed traffic line of crews in a sailing yacht and assessed working posture using OWAS, RULA and REBA tools. Also we suggested tips of Ergonomic design in the sailing yacht.

• 한국BIM학회 논문집
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• 제7권3호
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• pp.40-48
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• 2017

It only takes one failed project to wipe out an entire year's profit, when the projects are not managed efficiently. Additionally, escalating costs of materials and a competitive local construction market make subcontractors a challenge. Subcontractors have finite resources that should be allocated simultaneously across many projects in a dynamic manner. Significant scheduling problems are posed by concurrent multi-projects with limited resources. The objective of this thesis is to identify the effect of productivity changes on the total cost resulting from shifting crews across projects using a descriptive model. To effectively achieve the objective, this study has developed a descriptive cost model for a subcontractor with multi-resources and multi-projects. The model was designed for a subcontractor to use as a decision-making tool for resources allocation and scheduling. The model identified several factors affecting productivity. Moreover, when the model was tested using hypothetical data, it produced some effective combinations of resource allocation with associated total costs. Furthermore, a subcontractor minimizes total costs by balancing overtime costs, tardiness penalties, and incentive bonus, while satisfying available processing time constraints.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2005년도 춘계학술대회 논문집
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• pp.318-321
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• 2005

Crashworthy design of a train is a systematic approach to ensure the safety of passengers and crews in railway transportation for the prescribed accident scenarios. This approach needs new structural arrangements and designs to absorb higher levels of impact energy in a controlled manner and interior designs to minimize passenger injuries. In this paper, an evaluation method for crashworthiness of Korean tilting train express is introduced. Crush characteristics for each part of tilting train express are evaluated numerically through 3-dimensional shell element analysis with LS-DYNA. Based on a head-on collision and a level crossing collision scenarios, the crash behaviors of tilting train express are evaluated numerically using full-rake collision simulations.

• 한국경영과학회:학술대회논문집
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• 대한산업공학회/한국경영과학회 2000년도 춘계공동학술대회 논문집
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• pp.613-616
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• 2000

This paper considers the problem of subway crew scheduling. Crew scheduling is concerned with finding a minimum number of assignments of crews to a given timetable satisfying various restrictions. Traditionally, crew scheduling problem has been formulated as a set covering or set partitioning problem possessing exponentially many variables, but even the LP relaxation of the problem is hard to solve due to the exponential number of variables. In this paper, we propose two basic techniques that solve the problem in a reasonable time, though the optimality of the solution is not guaranteed. To reduce the number of variables, we adopt column-generation technique. We could develop an algorithm that solves column-generation problem in polynomial time. In addition, the integrality of the solution is accomplished by variable-fixing technique. Computational results show column-generation makes the problem of treatable size, and variable fixing enables us to solve LP relaxation in shorter time without a considerable increase in the optimal value. Finally, we were able to obtain an integer optimal solution of a real instance within a reasonable time.

• 한국항공운항학회지
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• 제22권2호
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• pp.81-86
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• 2014

In this paper, we states the verification and validation methodology for the modular system of A-SMGCS which defined in the ICAO Manual on Advanced Surface Movement Guidance and Control Systems. Such systems aim to maintain the declared surface movement rate under all weather conditions while maintaining the required level of safety. With the complete concept of an A-SMGCS, air traffic controllers, vehicle drivers, flight crews, and are assisted with surface operations in terms of surveillance, control, routing/planning and guidance tasks. A-SMGCS verification and validation for the development of Real Time Simulation, shadow mode trials, operational trials are conducted through three methods. In this study, the characteristics and the need for such a verification method was examined.

• 공학교육연구
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• 제15권5호
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• pp.82-86
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• 2012

These days, the cruise tourist industry is one of the most dynamic and fastest growing components of the leisure industry in the world. Therefore, the cruise ship with ubiquitous technology is expected to enhance the operation efficiency of the ship. It can also provide valuable addition to the ship's service as well as high quality of life to crews and passengers. Since a large number of passengers are dwelling in cruise ship, all passengers are not easy to use ship's facilities, such as restaurants, fitness center, swimming pool and spa at anytime they want. In this paper, passenger service system in ship environment is tested in similar environment and under ship operation condition. We have proposed three applications of ubiquitous technology using Zigbee communication and LabView program.

• Structural Engineering and Mechanics
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• 제51권1호
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• pp.163-180
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• 2014

In the displacement based finite element analysis of composite beams that consist of two Euler-Bernoulli beams juxtaposed with a deformable shear connection, the coupling of the displacement fields may cause oscillations in the interlayer slip field and reduction in optimal convergence rate, known as slip-locking. In this study, the B-bar procedure is proposed to alleviate the locking effects. It is also shown that by changing the primary dependent variables in the mathematical model, to be able to interpolate the interlayer slip field directly, oscillations in the slip field can be completely eliminated. Examples are presented to illustrate the performance and the numerical characteristics of the proposed methods.

• International Journal of Automotive Technology
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• 제5권3호
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• pp.173-180
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• 2004

An intensive study was conducted for the crash worthy structural design of the recently developed Korean High Speed Train (KHST). Two main design concepts were set up to protect both crews and passengers from serious injury in heavy collision accidents, and to reduce damage to the train itself in light collision accidents. A collision against a movable 15-ton rigid obstacle at 110 kph was selected from train accident investigations as the accident scenario for the heavy collisions. A train-to-train collision at the relative velocity of 16 kph was used for the light collision. The crashworthiness behaviors of KHST were numerically evaluated using FEM. Analysis results using 1-D collision dynamics model of the full rake consist and 3-D shell element model of the front end structure showed good crashworthy responses in a viewpoint of structural design. Occupant analyses and sled tests demonstrated that KHST performed well enough to protect occupants under the considered accident scenarios. Finally our numerical approaches were evaluated by a real scale collision test.