• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.24 no.4
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• pp.129-139
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• 2010

This paper presents a basic energy performance data of microturbine, renewable Energy(BIPV and Solar Collector System) and a hybrid energy system(geothermal system and microturbine) installed in hospital building. The efficiency of solar collector and BIPV system was 30[%], 10[%] individually, and lower than micro turbines. Finally, in energy performance aspect, microturbine and geothermal source heat pump system were a high-efficiency system in hospital building. It is confirmed hybrid energy systems also show the most powerful alternative energy system for green hospital building from the simulation results.

• Journal of the Korean Solar Energy Society
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• v.32 no.2
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• pp.1-10
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• 2012

A photovoltaic/thermal (PVT)solar system is the solar technology that allows for simultaneous conversion of solar energy into both electricity and heat. This paper compared the performance of PVT system with a conventional PV module and solar collector and analyzed electrical and thermal efficiency of PVT system in terms of solar irradiance and inlet temperature of the working fluid. Based on the experimental data, thermal and electrical efficiencies of he glazed PVT system were57.9% and14.27% under zero reduced temperature condition which were lower by 13.6% than the solar thermal absorber plate and by 0.08% than the PV module respectively. For the unglazed PVT system it had lower thermal efficiency than the solar thermal absorber plate but higher electrical performance than the PV module due to the cooling effect by the working fluid. However, total efficiency of the glazed PVT system was72.2% which was higher than combined efficiencies of the solar collector and PV module. Besides, total efficiency of the PVT system would be much higher if calculated based on unit area.

• 한국태양에너지학회:학술대회논문집
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• 2011.11a
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• pp.60-67
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• 2011

A photovoltaic/thermal(PVT)solar system is the solar technology that allows for simultaneous conversion of solar energy into both electricity and heat. This paper compared the performance of PVT system with a conventional PV module and solar collector and analyzed electrical and thermal efficiency of PVT system in terms of solar irradiance and inlet temperature of the working fluid. Based on the experimental data, thermal and electrical efficiencies of the glazed PVT system were 57.9% and 14.27% under zero reduced temperature condition which were lower by 13.6% than the solar thermal absorber plate and by 0.08% than the PV module respectively. For the unglazed PVT system, it had lower thermal efficiency than the solar thermal absorber plate but higher electrical performance than the PV module due to the cooling effect by the working fluid. However, total efficiency of the glazed PVT system was 72.2% which was higher than combined efficiencies of the solar collector and PV module. Besides, total efficiency of the PVT system would be much higher if calculated based on unit area.

• Journal of Digital Contents Society
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• v.18 no.8
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• pp.1671-1676
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• 2017

In theses days, data has been explosively generated in diverse industrial areas. Accordingly, many industries want to collect and analyze these data to improve their products or services. However, collecting user data can lead to significant personal information leakage. Local differential privacy (LDP) proposed by Google is the state-of-the-art approach that is used to protect individual privacy in the process of data collection. LDP guarantees that the privacy of the user is protected by perturbing the original data at the user's side, but a data collector is still able to obtain population statistics from collected user data. However, the prevention of leakage of personal information through such data perturbation mechanism may cause the significant reduction in the data utilization. Therefore, the degree of data perturbation in LDP should be set properly depending on the data collection and analysis purposes. Thus, in this paper, we develop the simulation tool which aims to help the data collector to properly chose the degree of data perturbation in LDP by providing her/him visualized simulated results with various parameter configurations.

• The Journal of Society for e-Business Studies
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• v.12 no.4
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• pp.71-84
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• 2007

The architecture for RFID-based home network and an intelligent agent for efficiently managing home network are proposed in this paper. The agent consists of six modules-Agent Manager, Data Collector, Execution Controller, Data Storage, Data Queue and User Interface. Agent Manager manages the tasks of modules, and Data Collector collects the data from home appliances through the RFID readersm Execution Controller determines the operations home appliances according to the conditions of the home environment and transfers the operations to the appliances through the RFID readers. Moreover, Data Storage keeps the data which is necessary for the operations of the agent, and Data Queue temporarily stores the data which is collected from home appliances. Lastly, User Interface provides the graphical user interface in which an individual can directly control and monitor the home network. The proposed intelligent agent autonomously learns the circumstances of a home network by analyzing the data about the state of home appliances, and controls home appliances according to the preference of the user. Therefore, the user can live in the best-suited home environment without direct appliance control if he/she performs home networking through the agent.

• Proceedings of the KSME Conference
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• 2001.06d
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• pp.152-157
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• 2001

UTC(Unglazed Transpired Collector) system has recently emerged as a new solar air heating technology. It is relatively inexpensive because it has not a glazed material. And it demonstrates efficient particularly for the applications in which larger wall area facilities with a high outdoor air requirement. Mathematical algorithm for UTC thermal modeling has been understood for further improvement of the system. EES and TRNSYS model of actual solar wall panel could be developed for computer simulations under other conditions. Computer models could be validated with the measured data from fixed outdoor test cell in KIER(Korea Institute of Energy Research). Major design parameters could be identified such as panel configuration and absorptivity and emissivity values for UTC design.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2009.10a
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• pp.273-277
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• 2009

This paper presents a basic energy performance data of micro gas turbine, Renewable Energy(BIPV and Solar Collector System, geothermal system) and a hybrid energy system(geothermal system and microturbine) installed in Hospital Building. The efficiency of solar collector and BIPV system was 30%, 10% individually, and lower than micro gas turbines. Micro gas turbines are small gas turbines that bum gaseous and liquid fuels to produce a high-energy exhaust gas and to generate the electrical power. Recently, the size range for micro gas turbines is form 30 to 500kW and power-only generation or in combined heat and power(CHP) systems. Finally, in energy performance aspect, Micro gas turbine system and hybrid energy system were high-efficiency system in hospital building. Hybrid energy system also give us a powerful alternative energy system economically.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.37 no.2
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• pp.1-4
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• 2000

We presented a method for extracting the base resistance r/sun bb/ based on analysis of the equivalent noise circuit for common collector. Measurements were conducted on devices with poly-emitter structure fabricated by BiCMOS process. Base resistance measurements have been performed for different base currents and structure. For low base current it is shown that the experimental data agree with theoretical expectations.

• JSTS:Journal of Semiconductor Technology and Science
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• v.3 no.1
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• pp.33-41
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• 2003

In this work, process optimization techniques for high frequency performance of HBTs are presented. The techniques are focused on reducing parasitic base resistance and base-collector capacitance, which are key elements determining the high frequency characteristics of HBTs. Several fabrication techniques, which can significantly reduce the parasitic elements of the HBTs for improved high frequency performance, are proposed and verified by the measured data of the fabricated devices.

• 유체기계공업학회:학술대회논문집
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• 1999.12a
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• pp.234-241
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• 1999

The flow at the impeller exit is important to validate engineering design and numerical analysis of pumps. However, it is not easy to measure the flow at the impeller exit and evaluate the impeller performance since there is usually strong interaction between the impeller and the volute casing. We installed axisymmetric collector instead of the volute casing, so there is no interaction between the impeller and casing. A 3-hole Cobra probe is used to investigate the flow at impeller exit and vaneless diffuser region for design and on design flow rate. For a single suction centrifugal pump of low specific speed, the flow field such as velocity, flow angle, and total pressure are measured by traversing the probe across the vaneless diffuser. These data can be used for performance prediction, desist and numerical analysis of pumps.