• The Transactions of the Korea Information Processing Society
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• v.7 no.7
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• pp.2095-2107
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• 2000

In maned ship, crews may have risks as they manage damage control system in IPMS in damage situations such as fire in a ship. So the application of unmaned autonomous systms can reduce the number of boarding crews and attribute to safe marine transportation. The paper suggests an intelligent system of the fire fighting control using fuzzy logic in Integrated Platform Management System which can take measures against fire situation of a ship excluding unnecessary warnings with undamaged situations. The system here detected the fire more accurately and adopted more appropriate measures according to ship status compared with conventional systems. Of all, a reduction of false detection of fires was noted.

• Korean System Dynamics Review
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• v.10 no.2
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• pp.29-52
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• 2009

This paper reveals the conceptual relation between High Level Radioactive Waste Repository Site(HLRWR) and Policy Acceptance of Local Residents thorough the Causal Loop Diagram. The Resident's policy acceptance depends on the perceived risk of that facility. To reduce the risks, government has to prepare the schemes of the total supporting program including cash and the local development programs.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.62 no.8
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• pp.1177-1183
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• 2013

In this paper, the analysis of inspection period bases on reliability is suggested in the field of traction power system. Even though there are several maintenance models, the most commonly used maintenance assessment has been focused on time based maintenance in real traction power systems. The maintenance intervals are selected on the basis of long-time experience. It ensures high availability and exact planning of staff. Reliability centered maintenance, which evaluates criticality and severity of each failure mode, achieves the operation, maintenance, and cost-effective improvement that will manage the risks of equipment. This paper deals with electrification in railway inspection frequency and applied reliability based inspection frequency instead of constant intervals. The distribution function of failure rate in traction power system belongs to Weibull function. Also, the fault data and the number of installed equipments for electrifications are collected. The failure history is investigated and classified in detail. Though these complicated procedures, it contribute to extend equipment lifetime and to reduce maintenance costs.

• Journal of the Korean Society of Systems Engineering
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• v.12 no.2
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• pp.19-27
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• 2016

Many countries concentrated on the space developments to enhance the national security and the people's quality of life. A space launch vehicle for accessing the space is a typical large complex system that is composed of the high-technology like high-performance, high-reliability, superhigh-pressure, etc. The project developing large complex system like space launcher is mostly conducted in the uncertain environment. To achieve a goal of the project, its success probability should be enhanced consistently by reducing its uncertainty during the life cycle: it's possible to reduce the project's uncertainty by performing the risk management (RM) that is a method for identifying and tracing potential risk factors in order to eliminate the risks of the project. In this paper, we introduce the risk management (RM) process applied for a Space Launch Vehicle R&D Project.

• Communications for Statistical Applications and Methods
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• v.17 no.1
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• pp.89-98
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• 2010

In this paper, a two-stage group sampling plan based on the time truncated life test is proposed for the Weibull distribution. The design parameters such as the number of groups and the acceptance number in each stage are determined by satisfying the producer's and consumer's risks simultaneously when the group size and the test duration are specified. The acceptable reliability level is expressed by the ratio of the true mean life to the specified life. It was demonstrated from the comparison with single-stage group sampling plans that the proposed plan can reduce the average sample number or improve the operating characteristics.

• Journal of the Korea Institute of Military Science and Technology
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• v.20 no.2
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• pp.289-299
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• 2017

Because of its unique ordnance or operational requirements, military aircraft has potential risks different from civil aircraft. This explains why there is no global document for military airworthiness and each nation has its own sovereign authority. But harmonized airworthiness activities among authorities are required to reduce cost and time for recent multinational programs. In this study, we show the airworthiness policy of the European Military Airworthiness Authorities and U.S. DOD Authorities which facilitate recognition of certificates and approvals issued by any other authorities. And we propose future works for Korea military airworthiness society to develop organizational recognition system.

• Journal of Environmental Science International
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• v.7 no.3
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• pp.327-334
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• 1998

The oil crisis of the 1970s and the rise in oil prices motivated people to implement energy conservation strategies. Buildings were fitted with additional Insulation and reduced ventilation rates. The reduction of mechanical and natural ventilation rate led to Increases In Indoor pollutant concentrations which result- ed In Increased health risks from Indoor exposure to pollutants. The variable-air-volume /bypass fitration system/VAV/BPFS) is a variation of the conventional VAV systems, The VAV/BPFS is an electronically controlled system that provides costegectlve thermal comfort and acceptable indoor air quality Under controlled conditions In a chamber, a series experiments were performed to compare the ability of a VAV/BPFS to remove Indoor aerosol concentration and to reduce energy consumption no that ability of conventional VAV system. Results show that the VAV/BPFS Increases the effective ventilation rate and removes indoor air pollutant, and maintains acceptable indoor air Quality without sacrificing energy consumption.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.10 no.5
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• pp.110-116
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• 2011

Water on a road surface can lower the coefficient of friction of vehicle tires and it involves lots of risks. One way to prevent water from staying is to cut many "rain grooves" into the edges of the pavement parallel. Such grooves, however, can exert unwanted side forces, particularly on passenger tires, which cause "Groove Wander" making the drivers uncomfortable. The "Groove Wander" is somewhat related to vehicle geometry, but is more strongly related to interaction between road grooves and tire tread's longitudinal grooves. This thesis tries to examine principles to estimate "Groove Wandering" effect focusing on the design of longitudinal groove. Additionally, it studied how to reduce pipe resonance longitudinal grooves form in the contact patch.

• Proceedings of the KSR Conference
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• 2010.06a
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• pp.1958-1963
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• 2010

Space Elevator introduced in the science fiction titled "The Fountatins of Paradise" by Arthur C. Clarke in 1979 could be attainable for the transportation of human and distribution from earth to space. Space Elevator could reduce shipping expenses and risks of the transportation system. Developing Space Elevator has to need rail technologies for the train and the rail using Carbon nanotube cable, installation of rail appropriated for Earth-orbiting. For this reason, rail technologies for developing Space Elevator will be suggested by this study through the case study.

• Proceedings of the Korean Nuclear Society Conference
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• 1998.05b
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• pp.470-475
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• 1998

The marginal nuclear criticality analysis for the high density spent fuel storage at a PWR plant was carried out by using the HELIOS and CASMO-3 codes. More than 20 % of the calculated reactivity saving effect is observed in this analysis. This mainly comes from the adoption of some important fission products and B-10 in the criticality analysis. By taking burnup and boron credits, the high capacity of the spent fuel storage rack can be more fully utilized, reducing the space of storage. Larger storage for a given inventory of spent fuel should result in remarkable cost savings and mort importantly reduce the risks to the public and occupational workers.