• Proceedings of the KSME Conference
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• 2001.11a
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• pp.629-634
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• 2001

The construction of the elevated railway has led to concerns about the noise from trains, particularly as tracks often pass close to residential dwellings. One specific issue relates to the noise from trains on bridges. The wayside noise for the train was measured to get the basic data that can be used to prepare count measures for solving environmental noise problems. Noise levels were measured simultaneously at three points in various distances from the railroad and at four points classified by floor. In this paper we measure the wayside noise in elevated railway and noise of normal operation compare with operating under train engine idling condition and investigate effect of nearby-building induced by train operation.

• Journal of Korean Society on Water Environment
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• v.40 no.2
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• pp.89-100
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• 2024

Climate change has a broad impact on the entire water environment, and this impact is growing. Climate adaptation in water supply systems often involves quantity and quality control, but there has been a lack of research examining the impacts of climatic factors on water supply productivity and operation conditions. Therefore, the present study focused on, first, building a database of climatic factors and water purification operating conditions, and then identifying the correlations between factors to reveal their impacts. News big data was analyzed with keywords of climatic factors and water supply systems in either nationwide or region-wide analyses. Metropolitan area exhibited more issues with cold waves whereas there were more issues with drought in the Southern Chungcheong area. A survey was conducted to seek experts' opinions on the climatic impacts leading to these effects. Pre-chlorination due to drought, high-turbidity of intake water due to rainfall, an increase of toxins in intake water due to heat waves, and low water temperature due to cold waves were expected. Pearson correlation analysis was conducted based on meteorological data and the operating data of a water purification plant. Heavy rain resulted in 13 days of high turbidity, and the subsequent low turbidity conditions required 3 days of high coagulant dosage. This insight is expected to help inform the design of operation manuals for waterworks in response to climate change.

• Journal of computational fluids engineering
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• v.16 no.2
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• pp.75-80
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• 2011

In this study, three-dimensional transient numerical simulations were carried out for a paint drying system of vehicle. The vehicle on assembly line passes through the drying system consisting of hot and cool air blow region. For the moving motion of the vehicle, moving of inlet boundary condition and MRF technique are used. The transient distribution of temperature and velocity in the drying system were predicted numerically. In order to validate the numerical results, transient distribution of the vehicle surface temperature was compared with experimental data, showing a good agreement. As a result of present study, optimal operating condition of the drying system are to be suggested.

• 유체기계공업학회:학술대회논문집
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• 2004.12a
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• pp.329-336
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• 2004

The lock-up position of the floating ring seal affects the leakage flowrate and the stability. And it is changed depending on the operating and geometry condition. In this paper, the leakage flowrate and stability with change of the height and length were investigated by theoretical analysis and experiment. The parameter of the height and length is expressed to the b and L. The decreasing of the b resulted in the increasing of equivalent whirl frequency ratio in the experimental result at the low speed and high pressure not such as theoretical analysis. As the L increased the leakage flowrate decreased and stiffness and direct damping coefficient increased in the experimental result. That was similar to the theoretical analysis.

• Proceedings of the KSR Conference
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• 1998.05a
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• pp.330-337
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• 1998

Bogie is mainly consisted of the bogie frame, suspensions, wheels and axles, braking system, and transmission system. The complex shapes of the bogie frame and the multiaxial loading condition induced in real operation make it difficult to design the bogie frame against the fatigue. In this study, multiaxial fatigue criteria were reviewed. Stress analysis of the bogie frame has been performed for the various loading conditions according to the UIC Code 615-4. Magnitudes of the stress amplitude and mean stress were estimated based on the stress analysis results to simulate the operating loads encountered in service. Fatigue strength of the bogie frame was evaluated by using the constant life diagram of the material. 3-D surface model ling, finite element meshing, and finite element analysis were performed by Pro-Engineer, MSC/PATRAN, and MSC/NASTRAN, respectively.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.64 no.1
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• pp.23-28
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• 2015

Two old synchronous condensers in Jeju are being replaced by new machines to operate Jeju AC network with Haenam-Jeju HVDC system stably. Before new synchronous condensers operate on site, voltage stability analysis is conducted to verify stable operation of jeju AC network. Through impedance analysis of the synchronous machine, transformer and ac network, the equivalent circuit is constructed and the voltage drop during start-up is calculated. Then, PSS/E fault analysis is performed to acquire short-circuit capacity according to the generator operation scenarios. Voltage variation when starting synchronous condenser is simulated in PSCAD/EMTDC and satisfies the operating condition of jeju AC network and HVDC #1 system.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2013.10a
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• pp.181-183
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• 2013

In case of hydrological observation system, Life time of facilities is different with operating environment and frequency of use. So, the durable year of the facilities is only considered to replace the facilities at present. Thus, system management is needed economical assesment based on condition evaluation through performance analysis of facilities. This research makes a proposal for scientific condition evaluation table through physical assessment, performance analysis assessment, durable years assessment about satellite communication facilities being used in K-water. Consequentially, reasonable replacement plan is established for satellite communication facilities.

• Korean Journal of Materials Research
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• v.28 no.6
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• pp.330-336
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• 2018

In this study, a membrane electrode assembly(MEA) composed of three electrodes(anode, cathode, and reference electrode) is designed to investigate the effects of methanol concentration on the overpotentials of anode and cathode in direct methanol fuel cells(DMFCs). Using the three-electrode cell, in-situ analyses of the overpotentials are carried out during direct methanol fuel cell operation. It is demonstrated that the three-electrode cell can work effectively in transient state operating condition as well as in steady-state condition, and the anode and cathode exhibit different overpotential curves depending on the concentration of methanol used as fuel. Therefore, from the real-time separation of the anode and cathode overpotentials, it is possible to more clearly prove the methanol crossover effect, and it is expected that in-situ analysis using the three-electrode cell will provide an opportunity to obtain more diverse results in the area of fuel cell research.

• Microbiology and Biotechnology Letters
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• v.33 no.1
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• pp.56-64
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• 2005

The occurrence and abundance of protozoa at advanced wastewater treatment plant were compared with operating parameters and effluent quality using statistical procedures. It seemed that plant operating conditions influenced the distribution of protozoa in the mixed liquor. In statistical analysis, the distribution of protozoa showed the operating condition of plant and predicted effluent quality. Once enough data concerning protozoa, operating parameters and effluent has been gathered, the operator has a valuable tool for predicting plant performance and near-future effluent quality based on microscopic examination. Plant operator manipulates operating conditions if he knows near-future effluent quality is deteriorating. Perhaps more importantly it can be used to actually control the plant to adjust the operating conditions to obtain the protozoal populations that have been shown to provide the best effluent quality.

• Korean Institute of Interior Design Journal
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• v.19 no.6
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• pp.3-10
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• 2010

The purpose of this study is to examine the state of utilization in sport facilities at a university and drew up the improvement plan for all students. To accomplish this work, the survey of the 445 students(male 221, female 224) were collected. The collected data were analyzed through the frequency analysis. All of sports facility is used for wide range of student who like to use as their leisure in order to learn variety experience for spending their spare time. Also sports facility of university accomplish social education function to all member of university. Having sports facility for university can also work as a promotion and new impression to people its university image as well as welfare for staff. Especially, excellent sports facility at university can provide public service to local people where university is located. Having sport facility at university is directly related to development of university in many way, university is required to implement effective program for operating sport facility at university.