• Proceedings of the KSR Conference
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• 2011.05a
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• pp.1134-1141
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• 2011

Costs have long since become a major issue in railway system analysis, attention is not limited to the acquisition costs alone, but encompasses all costs involved in the use and disposal of the systems. Concepts such as Life Cycle Cost(LCC), Costs Of Ownership(COO), or Total Ownership Cost(TOC) are more and more frequent in any document dealing with system analysis. Most of railway projects have applied this LCC Model to evaluate effectiveness of system acquisition cost. But these action of LCC model does not applied all the rest of system life cycle period due to the differences of its responsibility. This is why a study has been undertaken by the operation party to harmonize the most important aspects of the LCC model. This study focused on these and other objectives for introduction of method and needs for an action plan for maintenance actions involved relevant cost allocation.

• Journal of the Korean Ceramic Society
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• v.53 no.3
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• pp.343-348
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• 2016

Manganese and $TiO_2$ grown on Activated Carbon Fiber (ACF) was synthesized by hydrothermal method. The prepared composites were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM) with energy dispersive X-ray (EDX). The catalytic behavior was investigated through the decomposition of methylene blue (MB) and methyl orange (MO) as standard dyes under visible light. The degradation performance of the degraded standard dye solutions was determined by UV-Vis spectrophotometry. This enhanced photocatalytic activity arises from the positive synergetic effect among the Mn, $TiO_2$ and ACF in this heterogeneous photocatalyst. The process contributes to the release of abundant photocatalytic sites of Mn and $TiO_2$ and improves the photocatalytic efficiency. The excellent adsorption and photocatalytic effect with the explanation of the synergetic mechanism are very useful not only for fundamental research but also for potential practical applications.

• Journal of the Ergonomics Society of Korea
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• v.31 no.1
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• pp.143-149
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• 2012

Objective: The aim of this study is to gain an overview of the risk assessment and management system in the shipbuilding industry. Background: The use of risk assessment techniques has grown significantly in recent years. Method: Various references have been reviewed to evaluate risk assessment and management policy. Results: Adapting the risk assessment system has become an important approach not only to prevent industrial accidents but also to enhance the efficiency of works for shipbuilding workers. Conclusion: Risk assessment is an approved technology for operators to address larger hazards, and to ensure risks have been reduced to appropriate levels cost effectively. Application: These results can be used to provide baseline information for risk assessment and management policy.

• Tribology and Lubricants
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• v.28 no.4
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• pp.184-188
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• 2012

Alcohol components are illegally mixed with petroleum products for tax evasion purposes, but this degrades vehicle performance. The alcohol content in petroleum fuel can be analyzed by gas chromatography. However, this technique requires a long analysis time and is expensive. $CrO_3$, also known as Jones reagent, changes color upon reaction with an alcohol. In this study, therefore, we analyze alcohol contents in vehicle fuel by using $CrO_3$ aqueous solution.

• Proceedings of the IEEK Conference
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• 2005.11a
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• pp.505-508
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• 2005

This paper presents the high speed noise reduction processing system using the MDFT on the frequency domain. The proposed system use the linear prediction coefficients of the AR method based on the SLMS(sign least mean square). The signals with a random noise tracking per-formance are examined through computer simu-lations. It is confirmed that the high speed adaptive noise reduction processing system is realized by the SLMS algorithms with rapid convergence on the FD(frequency domain).

• 한국연소학회:학술대회논문집
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• 2014.11a
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• pp.21-24
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• 2014

In the entrained-flow coal gasifier, coal ash turns into a molten slag most of which deposits onto the wall to form liquid and solid layers. Critical viscosity refers to the viscosity at the interface of the two layers. The slag layers play an important role in protecting the wall from physical/chemical attack from the hot syngas and in continuously discharging the ash to the slag tap at the bottom of the gasifier. For coal with high ash melting point and slag viscosity, CaO-based flux is added to coal to lower the viscosity. This study evaulates the effect of critical viscosity temperature and ash/flux ratio on the slag behavior using numerical modelling in a commercial gasifier. The changes in the slag layer thickness, heat transfer rate, surface temperature and velocity profiles were analyzed to understand the underlying mechanism of slag flow and heat transfer.

• Proceedings of the Korean Vacuum Society Conference
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• 2016.02a
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• pp.214.2-214.2
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• 2016

플라즈마 공정은 공정의 미세화, 저온화의 필요성 때문에 반도체 및 태양전지 분야 등 여러 분야에서 널리 쓰이고 있으며 그 중요성은 점점 더 커져가고 있다. 그러나 플라즈마를 사용하는 공정에서 공정조건의 미세한 변화에 따라서 플라즈마 특성이 크게 바뀌어 공정조건에 따른 공정 결과의 예측을 어렵게 한다. 따라서 플라즈마를 이용하는 공정에 있어서 다양한 변수의 복합적인 상호작용을 고려하여 공정 결과를 예상 할 수 있는 시뮬레이션에 대한 연구가 요구되고 있다. 본 연구에서는 유도 결합형 플라즈마 발생 장치에서 공정조건에 따른 플라즈마 밀도 분포 변화를 전자기장 시뮬레이션을 통해 예상해보았으며, 시뮬레이션 결과를 실제 방전 상황에서 DLP(Double Langmuir Probe)로 측정한 값과 비교하여 플라즈마 밀도 분포와 전자기장 시뮬레이션의 정확성을 검토하였다.

• Proceedings of the KIPE Conference
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• 2011.11a
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• pp.309-310
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• 2011

풍력 발전 시스템을 설치하기 위해서는 사전에 타당성 조사가 반듯이 이루어져야 한다. 풍력자원 분석은 발전기 종별 발전량을 예측하여 효율적인 발전기(안전등급포함)를 선택할 수 있으며, 향후 발전기를 설치할 경우 선정지점의 지지 기반 및 기초공법에 관한 기초자료로 활용이 가능하다. 그러므로 본 논문에서는 12비트 분해 능력을 가지고 있는 DSP-f28335 마이크로 콘트롤러를 사용하여 IEC61400-1 국제기준에 준수하여 풍향, 풍속, 온도를 측정하고 저장이 가능한 풍력자원 분석장치를 개발하였다.

• 한국정보교육학회:학술대회논문집
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• 2010.01a
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• pp.221-226
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• 2010

In the flood of information in the modern society, which is information-oriented society and knowledge engineering society, the transition to learner-centered education is demanded in order to perform the task in hand and solve the problems. In this study, it is considered a prerequisite that students get motivated and interested in Sajasohak to study it. Thus, in teaching Sajasohak in various ways, we intend to design web-based multimedia contents by using a variety of forms of multimedia and apply it to the field(real classroom).

• Annual Conference of KIPS
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• 2006.05a
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• pp.589-592
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• 2006

상수도는 도시의 일상생활 및 제반 활동을 유지시키는 중요한 사회기반 시설임에도 불구하고 시설 확대 이외의 종합적 관리 대책이 제시되지 않아 시설 노후화 및 불량으로 인한 낭비 요소가 매우 높다. 이와 같은 문제를 해결하기 위해 이 논문에서는 상수도의 생산에서 각 수용가에서 사용되는 부분에 대한 다양한 성격의 데이터들을 데이터베이스화 하고 이에 대한 분석 및 평가를 통해 무효수량 발생 원인을 쉽게 찾아 신속하게 대응함으로써 적은 노력으로 유수율을 향상시킬 수 있는 소프트웨어 시스템의 개발을 목표로 한다. 이 논문에서 개발한 유수율 제고 시스템은 상수도 시설에 대한 직접 탐사 이전에 누수 및 무효수량 발생 원인을 정량적으로 분석 평가함으로써 적은 비용으로 유수율 향상에 크게 기여할 것으로 기대된다.