• 대한전기학회:학술대회논문집
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• 대한전기학회 2008년도 제39회 하계학술대회
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• pp.1326-1327
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• 2008

Recently, the air pollution is supposed is to be the most serious environmental problem. Therefore, a small air cleaner is asked to make comfortable indoor environment for the moderns who have frequent indoor activity. In this study, without generating of the second pollution source, dust in the air and harmful microorganisms can be removed by the electric dust collecting technology which has high reliability and efficiency to be able to remove the impurities even though it is just 0.01${\mu}m$. Accordingly, power sources of the dust collector use, it is not inefficiency and offering to dust collector unstable. In order to overcome the point at issue, a this study, for power factor compensating use the PFC circuit, for removing the noise use EMI filter and for generating the hight voltage use the Cockcroft Walton Circuit. And we study power source on characteristic and improvement.

• 한국안전학회지
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• 제15권1호
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• pp.106-111
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• 2000

EP(Electrostatic Precipitator) has been used to keep the natural environment from fly-ash in the industrial fields and operated in intermittent PEC(Pulse Energized Control) mode to improve dust-collecting efficiency. Intermittent PEC mode induces low-frequency harmonic currents into power system, therefore EP transformer vibrates. This continuous transformer vibration developes transformer abnormal audio-noise and if it is too much or operates in the region of natural frequency, transformer will be damaged in the end. EP interruption caused by transformer damage results in power generation stopped, power quality down and economic loss. Therefore, this paper explains harmonic currents and transformer vibration-core vibration, winding vibration, and proposes the measures of suppressing the vibration with EP operated in intermittent PEC mode. And this results is proposed to be used for future EP transformer design or EP control method to operate EP-concerned equipment safely keeping from system faults caused by transformer vibration.

• Journal of Information Processing Systems
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• 제12권3호
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• pp.436-454
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• 2016

This research presents the battery discharge rate models for the energy consumption of mobile phone batteries based on machine learning by taking into account three usage patterns of the phone: the standby state, video playing, and web browsing. We present the experimental design methodology for collecting data, preprocessing, model construction, and parameter selections. The data is collected based on the HTC One X hardware platform. We considered various setting factors, such as Bluetooth, brightness, 3G, GPS, Wi-Fi, and Sync. The battery levels for each possible state vector were measured, and then we constructed the battery prediction model using different regression functions based on the collected data. The accuracy of the constructed models using the multi-layer perceptron (MLP) and the support vector machine (SVM) were compared using varying kernel functions. Various parameters for MLP and SVM were considered. The measurement of prediction efficiency was done by the mean absolute error (MAE) and the root mean squared error (RMSE). The experiments showed that the MLP with linear regression performs well overall, while the SVM with the polynomial kernel function based on the linear regression gives a low MAE and RMSE. As a result, we were able to demonstrate how to apply the derived model to predict the remaining battery charge.

• Journal of Korean Society for Atmospheric Environment
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• 제24권E1호
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• pp.24-31
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• 2008

In this study, a new PM (particulate matter) sampler was developed and fabricated to collect fine particles in the atmosphere, and laboratory and field tests were carried out to evaluate the performance of the sampler. The PM sampler, which was based on impingers, employed an aerosol condensation system as a PM magnifier to improve its collection efficiencies. Sodium chloride, ammonium sulfate and ammonium nitrate aerosols were used as test particles, because these components are rich in ambient aerosols. As a result, it was found that the collection efficiency of the novel PM sampler was very high. Thus, it is believed that the PM sampler is an effective device for sampling fine particles. In addition, it was demonstrated that this work could contribute to the collection or removal of fine particles and be applied to the semicontinuous sampling of ambient aerosols for chemical composition analysis.

• 한국의류학회지
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• 제32권8호
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• pp.1286-1298
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• 2008

This study was attempted to examine the indigo dyeing technique in the latter Joseon Dynasty, and to find diachronic specifics in the indigo dyeing method from 17C to 19C. The results are as follows: First, There were 2 kinds of indigo species-Yoram(Polygonum tinctorium Lour.) and Sungram(Isatis tinctoria L.)-in the latter Joseon Dynasty. Dangram was preferred in particular among Yoram species because of its high dyeing efficiency. Sungram was mainly used for making Jeon(indigo sediment). Second, Yoram cultivation took the following order: Sowing in April${\rightarrow}$planting out in June${\rightarrow}$harvesting leaves in August${\rightarrow}$collecting seeds in September. Sungram had more harvesting times and wider harvesting period than Yoram. Third, all indigo dyeing methods were grouped into two categories, one was temporary dyeing method, the other was permanent dyeing method. Mixture dyeing of the boiled and the raw, raw leaves dyeing, and fermentation dyeing belonged to the temporary dyeing. Jeon dyeing and Gaeogi dyeing belonged to the permanent dyeing. Finally, diachronic specifics from 17C to 19C were as follows: Decline in the mixture dyeing of the boiled and the raw, development in the raw leaves dyeing, continuance of the fermentation dyeing, and naturalization of Jeon dyeing technique.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2009년도 춘계학술대회 논문집
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• pp.905-911
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• 2009

The viscosity drive method by the wheel which is widely used in the conventional railway systems needs a large friction force between the wheel and the guide-rail, which brings on a thrust force for a quick acceleration and a high-speed travelling. In addition, the viscosity drive method needs an increase of the vehicle weight for a large friction force. However, a maglev train is possible to be driven by the electro-magnet instead of the wheel, which produces a levitation and thrust force without any contact. In general, low-speed maglev train uses a linear induction motor(LIM) for propulsion that is operated under 300[km/h] due to the power-collecting and end-effect problems of LIM. In case of high-speed maglev train, a linear synchronous motor(LSM) is more suitable than LIM because of a high-efficiency and high-output properties. LSM has a driving principle as same as a conventional rotary synchronous motor(RSM), and the torque of RSM becomes the thrust force of LSM. A conventional LSM has relatively large air-gap compared with a conventional RSM. So, it must be achieved a design that is considered normal force by finite-asymmetric structure, end-effect on the entry and exit part, and support structure of a moving part. Therefore, in this research, authors accomplish a conceptualizing and basic design of a small-scaled LSM, and characteristics analysis using FEM.

• 디지털융복합연구
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• 제9권5호
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• pp.1-9
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• 2011

스마트그리드를 통해 소비자 선택 확대, 전력산업의 미래 변화에 적응과, 신재생에너지원의 사용증가 등의 여러 가지 편익을 도모 할 수 있다. 소비자는 적극적인 수요반응을 통해 시스템의 전반적인 효율성 향상에 기여하며 사업자가 제공하는 더 많은 정보에 기초하여 에너지이용 효율을 제고할 수 있다. 소비자보호를 위한 지능형전력망 정보의 수집, 활용, 보호에 대한 기본적인 법적 조항은 지능형전력망 구축 및 이용 촉진에 관한 법률에 제시되어 있다. 마지막으로 스마트그리드에 대한 소비자의 인식 제고를 위해 스마트그리드 홍보 및 교육 확대가 무엇보다 필요하다. 따라서 스마트그리드 소비자 수용성 제고 방안을 수립해야 한다는 것이다.

• 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.

• 한국태양에너지학회 논문집
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• 제29권3호
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• pp.12-18
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• 2009

The Knowledge of the solar radiation components are essential for modeling many solar energy systems. This is particularly the case for applications that concentrate the incident energy to attain high thermodynamic efficiency achievable only at the higher temperatures. In order to estimate the performance of concentrating thermal systems, it is necessary to know the intensity of the beam radiation, as only this component can be concentrated. The Korea Institute of Energy Research(KIER) has began collecting solar radiation component data since January, 2002. KIER's component data will be extensively used by concentrating system users or designers as well as by research institutes. The theoretical analysis of solar radiation as a component has compared with the experimental data obtained by the KIER station. The Result of simulation analysis shows that the annual-average daily diffuse radiation on the horizontal surface is $1,457cal/m^2$ and daily direct radiation on the horizontal surface is $1,632cal/m^2$ for all over the 16 areas in Korea.

• 디지털산업정보학회논문지
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• 제7권4호
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• pp.15-22
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• 2011

U-Healthcare service is a real-time service using the vital signs which are continuously transferred from monitoring sensors attached to mobile patients under the wireless network environments. It should monitor the health condition of mobile patients everywhere at any time. In this paper, we have improved two features of the three layered mobile patient monitoring system with load balancing ability. First, the simulation process has been improved by allowing the number of related nodes to be changed. Secondly, we have modified S node to which queue is added to reduce the loss rate of collecting data from patients during the delay of S node process. And the data from the patient with high priority can be transferred to the server immediately through the filtering function. Furthermore, we have solved the problem of redundancy in sharing information among S nodes by differentiating process time to each S node. By performing a DEVS Java-based system simulation, we have verified the efficiency of this improved system.