• Advances in Energy Research
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• v.5 no.4
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• pp.289-304
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• 2017

Large glazed surfaces and windows become common features in modern buildings. The spread of these features was influenced by the dependence of designers on mechanical and artificial systems to provide occupants with thermal and visual comfort. Countries with hot summer and cold winter conditions, like Jordan, require maximum shading from solar radiation in summer, and maximum exposure in winter to reduce cooling and heating loads respectively. The current research aims at designing optimized double-positioned external shading device systems that help to reduce energy consumption in buildings and provide thermal and visual comfort during both hot and cold seasons. Using energy plus, a whole building energy simulation program, and radiance, Lighting Simulation Tool, with DesignBuilder interface, a series of computer simulations for energy consumption and daylighting performance were conducted for offices with south, east, or west windows. The research was based on comparison to determine the best fit characteristics for two positions of adjustable horizontal louvers on south facade or vertical fins on east and west facades for summer and winter conditions. The adjustable shading systems can be applied for new or retrofitted office or housing buildings. The optimized shading devices for summer and winter positions helped to reduce the net annual energy consumption compared to a base case space with no shading device or with curtains and compared to fix shading devices.

• Bulletin of the Korean Chemical Society
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• v.25 no.2
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• pp.260-262
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• 2004

In agreement with the results of previous MP2 calculations by Sauers, B3LYP, CASSCF, and CASPT2 calculations on the parent 2-carbena-1,3-dioxolane show that it fragments to ethylene plus $CO_2$ by a concerted pathway with only a small energy barrier. Not only is fragmentation via stepwise C-O bond cleavage computed to be a much higher energy pathway, but the singlet diradical that would be an intermediate along such a reaction path is not even computed to be a local minimum on the potential energy surface.

• Transactions of the Korean hydrogen and new energy society
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• v.26 no.2
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• pp.156-163
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• 2015

The fuel cells have been investigated in the applications of marine as the high efficient and eco-friendly power generating systems. In this study, modeling of IR Type molten carbonate fuel cell (Internal Reforming Type molten carbonate fuel cell) has been developed to analyze the feasibility of thermal energy utilization. The model is developed under Aspen plus and used for the study of system performances over regarding fuel types. The simulation results show that the efficiency of MCFC system based on NG fuel is the highest. Also, it is also verified that the steam reforming is suitable as pre-reforming for diesel fuel.

• Bulletin of the Korean Chemical Society
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• v.20 no.3
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• pp.345-351
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• 1999

The structures, the energetics, and the spectra of K+(H2O)3 have been studied at HF and MP2 levels with the basis set of triple-zeta plus two sets of polarization functions (TZ2P) for water molecules. Two structures considered are 3+0 (D3), and 2+1 (C2v). The 2+1 (C2v) has two hydrogen bonds between the primary hydration and the secondary hydration shell water molecules. They have similar binding energy and enthalpy. The most stable conformation of K+(H2O)3 is entropy driven as shown in Na+(H2O)5 and in Na+(H2O)6 cases. The 3+0 (D3) conformation is the most stable at 298 K and at 1 atm, based on Gibbs free energy changes (ΔGr). The thermal contributions to the enthalpy and the Gibbs free energy are corrected for the low frequency modes. The corrected ΔGr is in good agreement with the experimental value. Vibrational frequencies of two conformations are revealed as their characteristics.

• 제어로봇시스템학회:학술대회논문집
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• 2003.10a
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• pp.2514-2518
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• 2003

The KAERI Spent Fuel Remote Technology Development (SFRTD) Department is developing the remote maintenance and repair equipment, which is used in a hot cell in an intense radiation field, as part of a project to develop the Advanced spent fuel Conditioning Process (ACP). Although several mechanical master-slave manipulators (MSMs) is mounted on the hot cell wall, their reach will be limited and cannot access areas for all the ACP equipment maintenance. A Bridge Transported ServoManipulator (BTSM) has been designed to overcome the limitation of access areas that is a drawback of MSMs for the ACP equipment maintenance. The BTSM system consists of four components: a transporter with telescoping tubeset, a slave manipulator, a master manipulator, and a remote control system. The BTSM system has been designed by Solid Edge that is a 3D computer-aided design (CAD) software, except for the remote control system. The master manipulator and the slave manipulator are kinematically similar in design, except for the handle and the tong, respectively. The manipulators have 6 degrees of freedom (DOF) plus the jaws motion. The transporter has traveling, traverse, and hoisting motion to position the slave manipulator.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.27 no.11
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• pp.567-573
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• 2015

Commercial buildings account for significant portions of the total building energy in Korea, and thus, a variety of research on chiller operation has been carried out. However, most of the studies were carried out on the chiller itself, i.e., the part load ratio characteristics and the corresponding electricity energy consumption patterns were not analyzed in existing studies. In this study, the part load ratio and the operating characteristics of the vapor compression chiller were analyzed within an office building equipped with the conventional variable air volume system. As a result, significant portions of total operating hours, cooling load, and energy consumption turned out to be in the part load ratio range of 0 through 50%. Thus, energy consumption was significantly affected by the chiller COP at low part load conditions, indicating that chiller operation at the part load is an important factor in commercial buildings.

• Nuclear Engineering and Technology
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• v.32 no.4
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• pp.361-371
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• 2000

The 123Te(p,n)123I, 124Te(p,n)124I and 124Te(p,2n)123I reactions, among the many reaction channels opened, are the major reactions under consideration from a diagnostic purpose because reaction residuals as the gamma emitters are used for most radiophamaceutical applications involving radioiodine. Based on the available experimental data, the absorption cross sections and elastic scattering angular distributions of the proton-induced nuclear reaction on Te isotopes below 60 MeV are calculated using the optical model code APMNK. The transmission coefficients of neutron, proton, deuteron, trition and alpha particles are calculated by CUNF code and are fed into the GNASH code. By adjusting level density parameters and the pair correction values of some reaction channels, as well as the composite nucleus state density constants of the pre-equilibrium model, the production cross sections and energy-angle correlated spectra of the secondary light particles, as well as production cross sections and energy distributions of heavy recoils and gamma rays are calculated by the statistical plus pre-equilibrium model code GNASH. The calculated results are analysed and compared with the experimental data taken from the EXFOR. The optimized global optical model parameters give overall agreement with the experimental data over both the entire energy range and all tellurium isotopes.

• Journal of the Korean Solar Energy Society
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• v.31 no.5
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• pp.146-155
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• 2011

Sustainable building is getting more and more important topic in 21C. Following this trend, building energy saving standard has been reinforced in Korea. Especially, insulation standards are revised continuously after1979. This study aims to evaluate the correlation between the revised insulation standards and heating and cooling loads of a residential building. This study shows that the standard of insulation is more related with heating load than cooling load, and cooling load is more related with other sources such as glass types and solar incidence through windows. In case of highly-insulated building such Passive Houses or Zero Energy Houses, the cooling load should also be considered as important as heating load when revising the building energy saving regulations in the future.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.29 no.3
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• pp.97-104
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• 2017

Reinforcement of insulation in apartment buildings reduces the heating and cooling energy consumption by lowering the heat transfer in the building envelope. There are differences between internal and external insulation methods in heat transmission properties. However, some building load calculation programs cannot analysis the differences between the two. This is because these programs do no account for the timelag or thermal storage effect of the wall according to the location of insulation. In this study, the heat transmission characteristics of internal and external insulation were analyzed by EnergyPlus, and heating and cooling energy demand was compared. The results showed that external insulation system had lower heating and cooling loads than internal insulation system. Also the heat transfer rate of external insulation is steadier than internal insulation. About 13.6% of heating and cooling energy demand decreased when the outdoor wall was finished with external insulation compared to the demand with internal insulation.

• Journal of Power Electronics
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• v.3 no.4
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• pp.230-238
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• 2003

Electric vehicles (EV) demands for greater acceleration, performance and vehicle range in pure electric vehicles plus mandated requirements to further reduce emissions in hybrid electric vehicles (HEV) increase the appeal for combined on-board energy storage systems and generators. And the power electronics plays an important role in providing an interface between fuel cells (FC) and loads. This paper deals with a multiple input DC-DC power converter devoted to combine the power flowing of multi-source on energy systems. The multi-source is composed of (i) FC system as a prime power demands, (ii) super capacitor banks as energy storage devices for high and intense power demands, (iii) superconducting magnetic energy storage system (SMES), (iv) multiple input DC-DC power converter and (v) a three phase inverter-fed permanent magnet synchronous motor as a drive. In this system, It is used super capacitor banks and superconducting magnetic energy replaces from the battery system. The modeling and transient performance simulation is effective for reducing transient influence caused by sudden charge of effective load. The main purpose of power electronic converters is to convert the DC power output from the fuel cell and other to a suitable AC voltage, which can be connected to electric loads directly (PMSM). The fuel cell and other output is connected to the DC-DC converter, which regulates the DC link voltage.