• 대한조선학회논문집
• /
• 제42권3호
• /
• pp.249-258
• /
• 2005

Recently, the vibration reduction at a local structure such as compass deck has been continuously requested by ship owner and shipbuilder. Because crews are afflicted with vibration, severe vibration problems even bring about a damage of structure. This study conducted to get an optimized stiffener size of compass deck to reduce the vibration level and decrease the weight of structure in ship. NASTRAN external call type optimization software (OptShip) which makes use of NASTRAN as a solver is used as an optimization tool. The results indicate that the optimum design is promising for real applications.

• 한국철도학회:학술대회논문집
• /
• 한국철도학회 2004년도 추계학술대회 논문집
• /
• pp.646-651
• /
• 2004

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, crashworthy design approach is applied to the tilting train express (TIX) design which is newly being developed. Based on a head-on collision and a level crossing collision scenarios, the crash behaviors of a TTX design candidate arc evaluated numerically using the finite element method. Finally, design alternatives which show better crashworthy performances are proposed and verified through the full-rake collision simulations.

• 조명전기설비학회논문지
• /
• 제28권4호
• /
• pp.36-41
• /
• 2014

Most faults that occur on transmission lines are caused by extreme weather with lightning storms in the distance. These are not only prolongs the time of removing and recovering, but also increases economical damages. If faults can be precisely located, maintenance crews can reach them quickly, and remove the faults in time. So, the precise locating of the faulted point on a transmission line is very important to improve the system reliability, and decreases economic damages as an inherent consequence of long term outages. Also, fault location methods are becoming of much importance for utilities and research. In this paper, two single-terminal impedance-based fault location techniques will be investigated to show the reliability and evaluated the performance of reactance and Takagi method by using MATHCAD program simulations.

• 대한인간공학회지
• /
• 제20권2호
• /
• pp.99-111
• /
• 2001

Human factors is a key issue in the maritime industry including ship design and navigation safety. Human factors for ship design is to optimize safety and convenience of crews and passengers. And human factors for navigation safety is to minimize marine accident occurrence by human and organizational error. There are several technical requirements to incorporate human factors and marine system Risk analysis. human behaviour analysis and human M&S(modeling and simulation) are examples of technical requirements. This paper provides the key issues and technologies of human factors for ship design and navigation safety.

• 한국철도학회:학술대회논문집
• /
• 한국철도학회 2003년도 춘계학술대회 논문집
• /
• pp.686-693
• /
• 2003

An intensive study was conducted for crashworthiness structural design of recently developed Korean High Speed Train. Two nam design concepts are setup to protect the both crews and passengers from serious injury at heavy collision accidents, and to reduce damages of the train itself at light collision accidents. For occupant protection a collision against a movable 15 tons rigid obstacle at 110 kph and a train-to-train collision at 30 kph were selected as accident scenarios for the heavy collisions based on the train accident investigations. A train-to-train collision at 8 kph was used for the light collisions. The crashworthiness behaviors of KHST have been evaluated numerically using the finite element method. Also, one-dimensional collision analyses show good crashworthy responses in a full rake consist and 3-dimensional shell element analyses do in the front-end structures of the power car. Occupant analyses and sled tests demonstrated that KHST performs well enough to protect occupants under the considered accident scenarios.

• 한국철도학회:학술대회논문집
• /
• 한국철도학회 2003년도 춘계학술대회 논문집
• /
• pp.222-231
• /
• 2003

After the reform of rail industry, a system to evaluate service qualities is required for the continuous improvement of railway service and the strength of competitiveness. This research provides evaluation categories and indices which are considered to be suited to the evaluation of rail service qualities. This study provides 4 categories and 11 indices to assess the rail service qualities: provision-operation interval/average operation speed, reliability-regularity/operation cancellation rate, safety- train usage term/facilities for the weak, client satisfaction- easiness of reserving and purchasing of tickets/comfort of queuing facilities/ kindness of train crews/ pleasantness of trains/provision of information, etc.

• 한국군사과학기술학회지
• /
• 제8권2호
• /
• pp.14-21
• /
• 2005

This paper describes the system for detecting the tank crew's(loader's) hand, arm, head and the upper half of the body in a danger area between the turret ceiling and the upper breech mechanism by computer vision-based method. This system informs danger of pressed to death to gunner and commander for the safety of operating mission. The camera mounted ort the top portion of the turret ceiling. The system sets search moving object from this image and detects by using change of image, laplacian operator and clustering algorithm in this area. It alarms the tank crews when it's judged that dangerous situation for operating mission. The result In this experiment shows that the detection rate maintains in $81{\sim}98$ percents.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 1996년도 하계학술대회 논문집 B
• /
• pp.701-703
• /
• 1996

Maintenance scheduling plays an important role in evaluating the supply reliability of power systems. Since generating units must be maintained and inspected, the generation planner must schedule planned outages during the year. Several factors entering into this scheduling analysis include: seasonal load-demand profile, amount of maintenance to bo done on all generating units, size of the units, elapsed time from last maintenance, and availability of maintenance crews. This paper proposes a new algorithm to decide the multi-year maintenance scheduling with considering the total cost. We adjust the maintenance scheduling to levelize the reliability over all period. The proposed algorithm is applied to a real size power system and the developed reliability results are obtained.

• 한국소음진동공학회논문집
• /
• 제21권7호
• /
• pp.650-656
• /
• 2011

The noise inside a naval vessel is very important in considering the need for hearing protection, improving the working environment and maintaining good communications for crews living on board a naval vessel. The indoor noise of a ship usually is specified by the A-weighted sound pressure level, but other evaluating parameters are required to reflect human senses more effectively. This paper uses additional noise indices related to room acoustics, such as NR(noise rating), NC(noise criterion), RC(room criterion), PSIL(preferred speech interference level) and loudness level to evaluate the noise inside cabins on a naval vessel. Using these psychological noise indices, allowable limit of noise level in cabins is suggested through psycho-acoustic evaluation for the noise in cabins.

• 한국소음진동공학회:학술대회논문집
• /
• 한국소음진동공학회 2001년도 추계학술대회논문집 II
• /
• pp.1313-1316
• /
• 2001

Generally, container carrier has larger engine than other commercial vessels and the engine casing is located in accommodation space. Therefore, the noise levels of cabins and engine room could be exceeded the specified noise limits and might be an annoyance to crews, and which can result in poor ship quality. Main subject of this study is to predict noise levels of the 4,500 TED container carrier by statistical energy analysis method in order to comply with contracted noise limits and to compare with the measured values. Additionally, through the contribution analysis of noise sources to each cabins, and appropriate countermeasures are proposed and the reduction effect of each noise control measure is studied by the analysis method. This study will contribute to reduce the noise levels of similar vessel.