• 한국산학기술학회논문지
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• 제16권5호
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• pp.3587-3595
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• 2015

본 연구에서는 저비용의 저심도 도시철도시스템을 구축하기 위하여 산업부산물인 고로슬래그 미분말, 플라이애시 및 급냉 전기로 산화슬래그를 사용하여 개발된 저탄소 친환경 PC 박스용 콘크리트의 역학적 성능 및 내구성을 평가 하였다. 역학적 특성을 평가한 결과, 재령 1일 압축강도는 모든 조건에서 설계기준강도($f_{ck}$) 35MPa의 90% 이상 강도 발현 하는 것으로 나타나 공기단축 가능으로 건설비용을 절감할 수 있을 것으로 판단된다. 또한, 소요의 물성 및 설계기준강도($f_{ck}$) 35MPa를 만족하는 범위에서 시멘트 단독 사용 조건보다 염소이온침투성 및 확산계수가 낮게 나타나 내염성능이 우수한 것으로 나타났으며, 동결융해 저항성 및 화학저항성의 경우에도 내구성능이 우수한 것으로 나타났다. 따라서 저탄소 친환경 PC 박스용 콘크리트를 사용할 경우, 시멘트 제조 시 발생되는 이산화탄소 및 환경부하를 저감할 수 있을 것으로 기대된다.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2011년도 춘계학술대회 논문집
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• pp.1009-1013
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• 2011

Seoul Metro Line 1 to 4 guests per day to 4.5 million people have been using the subway. This is close to the city population, 57 percent of people use the subway and found that 57 percent of people use the subway and found that this is close to the city population. Motor vehicle indoor air quality, especially of the major factors affecting is passenger's clothing, cosmetics, adhesives and formaldehyde by the action and so are able to keep. Enclosure 30ppm formaldehyde during prolonged exposure at concentrations above the nose, bronchial cough and a burning can cause symptoms. It is necessary to introduce an appropriate ventilation system. 1-4 Line Press in 2008, leaving the subway, and normally the train measured in room air quality. Measurements in 2005, $19.3{\sim}83{\mu}g/m^3$, 2008 Year ND ~ $61.7{\mu}g/m^3$ is. When congestion(rush hour) to temporarily increase the formaldehyde can result in a higher number. Automatic detection of formaldehyde and improve ventilation to a practical system, and it is necessary to chatneun. In research since 2006, Removal of formaldehyde were analyzed for the study. the passengers on the effects of formaldehyde in rush hour, the plan for increasing the ventilation through the analysis of various factors, such as electric vehicle practical ways to improve air quality have been studied.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2011년도 정기총회 및 추계학술대회 논문집
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• pp.2357-2364
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• 2011

Diesel locomotive operates the generator with the power from the diesel engine, and it consists of the typical serial-hybrid system which operates the train wheels by converting its generated electric energy into the torque of DC (or AC) motor. However, the technology of locomotives is only focused on trains' controlling power generation mechanism. Hence, it is a current issue that the efficiency of its engine and its generator is relatively lower than that of auto vehicles'. Particularly, since there are no proper equipment to measure the amount of fuel which is essentially necessary for the efficient use of fuel, it is not easy to confirm the instant amount of fuel use as well as the exact average fuel consumption per an hour. Due to those difficulties, it is urgent to develop the device that measures the fuel consumption. Plus, this use of the developed measuring device allows the various and useful analysis relating to the fuel consumption, and this could lead to establishing the efficient driving pattern regarding to fuel saving. This device consists of two flux (fuel level) measuring censors, MCU for calculating the measured values, the information recorder for saving measured values, and the display device for indicating the fuel amount consumed during driving.

• 한국분무공학회지
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• 제18권4호
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• pp.209-214
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• 2013

The present study aims to determine the optimized shape for the maximum electric energy production of building integrated photovoltaic system (BIPV) noise barrier through numerical analysis. The shape of BIPV noise barrier is one of the important factors in determining angle difference between direction vector of the sun and normal vector of the sound barrier surface. This study simulated numerically the flow and thermal fields for different angles in the range from $90^{\circ}$ to $180^{\circ}$, and from the results, the amount of isolation onto noise barrier surface was estimated along the angle between ground and top side of noise barrier. The commercial CFD code (Fluent V. 13.0) was used for calculation. It was found that the maximum amount of insolation per unit area was 19.6 MJ for $105^{\circ}$ case during a day in summer and was estimated 12.4 MJ in $150^{\circ}$ case during a day in winter. The results of the summer and winter cases showed the different tendency and this result would be useful in determining the appropriate shape of noise barrier which can be mounted under various circumstances.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2001년도 춘계학술대회 논문집 전력기술부문
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• pp.210-213
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• 2001

This study presents an effective variable forgetting factor method based on fuzzy logic to suppress frequency droop in extended integral load frequency control. The performance of the extended integral control is greatly dependent on the decaying factor. For an optimal or near optimal performance, it is necessary that the decaying factor as well as the feedback gains should be changed very quickly in response to changes in the system dynamics. However, because of its time-varing characteristic, the optimal decaying factor is difficult to be selected analytically. By adopting fuzzy set theory, the decaying factor can be determined quickly to respond to the variation of the feedback signals. This study builds a fuzzy rule base with use of the change of frequency and its rate as inputs. The computer simulation has been conducted for the single machine system. The simulation results show that the proposed fuzzy 1o81c based controller yields more improved control performance than the conventional PI controller.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2009년도 춘계학술대회 논문집 전기설비전문위원
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• pp.10-12
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• 2009

Electromagnetic Interference(EMI) in electric railway operation has become increasingly important. The components within very high power electronic, and the circuits for treating low-level signals, comprise complex system that must coexist and be highly reliable. To study it, It were included how much the HEMU-400X generates EMI and it has an effect on the power conversion units which resulted from Power Line Disturbance (PLD) phenomenon by contact loss during its running. In this study, the dynamic characteristic of a contact wire and pantograph suppling electrical power to high-speed trains are investigated. The analysis of the loss of contact based on Power Simulator program software is performed to develop power line disturbance model suitable for high speed operation. It is confirmed that a contact wire and pantograph model are necessary for studying the dynamic behavior of the pantograph system.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2005년도 춘계학술대회 논문집
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• pp.27-33
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• 2005

Constant load model is generally used for an electric train to perform the static analysis of AT feeding systems. In this model, the train will be considered as a constant load model when it drives or as a constant source model when it applies regenerative brake. However there must be some voltage constraints on the catenary in actual operations. These constraints are established for the reason of protecting the feeding facilities from excessive rise of regenerative braking voltage or guaranteeing the minimum traction power of train. In normal operating situation, the pantagraph voltage of the train should be maintained within these limits. Keeping these facts in minds, we suggest new methods of analyzing AT feeding systems using the constant power models with the conditions of voltage constraints. The simulation results from a sample system using the proposed method illustrate both the states of system variables and the supply-demand relation of power among the trains and the systems very clearly, so it is believed that the proposed method yields more accurate results than conventional methods do. The proposed methods are believed to contribute to the assessment of TCR-TSC for compensating reactive powers too.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2007년도 춘계학술대회 논문집
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• pp.1168-1173
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• 2007

The Seoul Subway is one of the most heavily used Subway System in the world. It provides reliable transportation services, conveys nearly 4 million Passengers across 117 subway stations with a length of 134.9 Km. Over the years the safety for the Subway has been a major concern, trains going off the track, equipment failure, careless operation, Signal failure are increasing day by day. In a Recent Public opinion 40% said the causes to above facts are Vehicle breakdown because of Operators, Old rail defect, Quality of material. 20% of the opinion said the obstacles were because of Operation, crew carelessness, negligence in signal operation. In case of any accident the crew members cannot resolve the issue on site (Aid insufficiency), because of lack of knowledge and carelessness. The main obstacles for Subway are vehicle breakdown, Electric equipment failure, Signal Equipment failure, and Crew carelessness. This paper aims to provide major problems which are needed to be solved as quickly as possible for citizen's safety for a comfortable subway system making a comfortable ride and providing better service gradually.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2008년도 춘계학술대회 논문집
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• pp.996-1001
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• 2008

To stop the train safely within the limited traveling distance and reduce its speed to the desired speed, it is necessary to guarantee the correct braking force. Presently, most trains have electric propulsion system and have adopted combined electrical and mechanical(friction) braking system. The friction coefficient between brake disc and pad is an important parameter in determining the mechanical braking force. In general, friction coefficient data of braking material have been taken through the dynamo-test in a laboratory. This study have suggested two methodologies that can measure friction coefficient of braking material on the train's actual operating condition. The first is the direct method; measure the brake force and the clamping force applied on the mechanical brake by using strain gauges installed at the brake disk, and then calculate it. The second method is the indirect method; obtain the friction coefficient by using the train load and the equivalent brake force which is deducted the longitudinal force, such as resistance to motion, gradient resistance and curved resistance, from the inertia force applied to the train.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2009년도 춘계학술대회 논문집
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• pp.612-618
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• 2009

Recently the roles of railways about the prevention of global warming caused by greenhouse gases and for low carbon green growth are larger than ever. And the railroad-related research institutions have been active in researching for energy conservation. Especially the urban railroad has been emerged as the best means of transportation compared to the general public transportation systems in punctuality, stability, ecology and etc. In operating the urban railroad system there are various ways for energy savings. In the larger category, One is the hardware aspect according to the structure of the vehicle and the development of control systems. The other is the software aspect which efficient train operation can be made through control of driving patterns and driving diagram. In this paper, there is sense to analyze the result in verifying expectation relation with variable and the use of electric power on this after selecting main variables that can influence to the energy of the train operation in the software aspect. First, after collecting the basic data related to operation(train speed, operating hours, power consumption, the position of stopping station, electrical power system etc.) and according to this, investigating the consumption of the energy of the operation, in the side of energy consumption deducing and analyzing problem, this will be found solutions.