• Proceedings of the KWS Conference
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• 2002.10a
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• pp.1-14
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• 2002

There is a continuous development of the most common welding processes like MMA, MIG/MAG, PAW and SAW. At the same time there is a conversion from stick electrodes to solid and cored wires with an increased productivity as a result. In parallel with these changes new processes are introduced and implemented. The number of Friction Stir Welding installations is starting to grow fast Hybrid laser welding has probably made a technical break through. The Magnetic Pulse Welding process is taking off. The different mechanical joining methods; clinching and self-piercing riveting; must not be forgotten. Structural adhesive is another method to consider.

• YAKHAK HOEJI
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• v.3 no.1
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• pp.26-34
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• 1957

The solar evaporation method is one of the most important and popular salt manufecturing method in Korea. The rate of evaporation of sea water depends on a complex climate factors. Of these factors, the most important is solar radiation and in particular the extent to which it is absorbed in the brine. By the addition of suitable dyestuff, a further increase in absorption is obtained and can result in all the radiation entering the brine being made available as heat. "Solivap Green", one of several dyestuffs which have been suggested for accelerating solar evaporation, was tested in this experiment. The results of the experiment. 1. Increase the evaporation rate of brine up to 20-25%. 2. Elevate the temperature of brine 2-$4^{\circ}C$. higher than that of brine adding no dyestuff. 3. Optimum dyestuff concentration is 25-30 mg/L and allowable maximum concentration can not exceeded 1000 mg/$m^2$ (50 mg/L). 4. Addition of dyestuff does not cause the degradation of salt produced. 5. A conversion table which indicates the concentrations for various depths of brine was prepared for engineering purpose. 6. Absorption spectrum of the dyestuff was studies, but toxicological and structural studies for the dyestuff have not been done in this experiment.

• KIEE International Transaction on Electrical Machinery and Energy Conversion Systems
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• v.12B no.1
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• pp.19-23
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• 2002

This paper investigates the influence of various stator pole shapes and yoke structures in Switched Reluctance Motors (SRM) on the mechanical behavior caused by the electromagnetic farce. The stator part in SRM produces most vibration. The geometric design of the stator is therefore necessary to reduce the vibration. Based on electromagnetic and structural Finite Element Method (FEM), the free and farced vibrations for the various structures of SRM with 6/4 poles are analyzed. Then a less vibration stator structure is proposed. Some of numerical computations for a prototype motor are verified by experimental results.

• Journal of the Korean Electrochemical Society
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• v.10 no.2
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• pp.141-144
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• 2007

Polypyrrole(PPy) was composite with MWNT to attain cycle stable by chemical method. We have been considered PPy is the ideal material for high energy density electrochemical capacitor due to pseudo capacitor reaction. In this study we found that increase in cycle life due to composite MWNT. Also PPy/MWNT composite material have resulted larger capacitance and exhibits better electrochemical behavior. The structural feature was investigated by using SEM and TEM. The PPy/CNT composite is not only a promising ultracapacitor material for energy storages but also has a good possibility because of its great capacitive properties, simple preparation and low cost.

• Proceedings of the Korean Society of Marine Engineers Conference
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• 2006.06a
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• pp.289-290
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• 2006

We report a study of Zn(S)Se/GaAs heterojunction solar cells grown by molecular beam epitaxy (MBE). Zn(S)Se/GaAs heterostructures prepared under different conditions were characterized in-situ by reflection high-energy electron diffraction (RHEED). Structural and electrical properties were investigated with double crystal X-ray diffraction and current-voltage characteristics, respectively. The fabricated $n-ZnS_{0.07}Se_{0.93}/p-GaAs$ solar cell (SC #2) exhibited open circuit voltage($V_{oc}$) of 0.37 V, short circuit current($I_{sc}$) of $1.7{\times}10^{-2}$ mA, fill factor of 0.62 and conversion efficiency of 7.8 % under 38.5 $mW/cm^2$ illumination.

• International Commerce and Information Review
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• v.10 no.3
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• pp.101-116
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• 2008

Future e-Trade RFID/USN distribution should satisfy the new needs of reasonable customers such as efficient supply of goods, presentation of information, and communication by developing intermediate and long-term strategies through analysis of industrial conditions and customers' needs. Through preferential application of new technology, knowledge-based e-Trade RFID/USN distribution environment and DB of industrial portal sites should be developed, RFID/USN infra such as Supply Chain Management(SCM) should be expanded, future-oriented knowledge-based services should be developed to prepare specific and realistic plans for proper UT(Ubiquitous Technology). Such change in e-Trade distribution environment should have historical and environmental backgrounds to suggest specific tasks and directions as a conversion of structural concept of engineering and trade theory for new u-Trade. Accordingly, this study is to present all the problems available in RFID/USN distribution, develop an organized and technological estimate model and provide a foundation to apply it efficiently. This study aims to present an interpretational foundation of RFID/USN distribution, rather than technical directions.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2003.07a
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• pp.176-180
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• 2003

Tri-crystalline silicon (Tri-Si) wafers have three different orientations and three grain boundaries. In this paper, tri-Si wafers have been used for the fabrication of buried contact solar cells. The optical and micro-structural properties of these cells after texturing in KOH solution have been investigated and compared with those of cast multi-crystalline silicon (multi-Si) wafers. We employed a cost effective fabrication process and achieved buried contact solar cell (BCSC) energy conversion efficiencies up to 15% whereas the cast multi-Si wafer has efficiency around 14%.

• KIEE International Transaction on Electrical Machinery and Energy Conversion Systems
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• v.2B no.3
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• pp.95-99
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• 2002

This paper deals with the influence of the various stator structures in a Switched Reluctance Motor (SRM) on the vibration behaviors. The stator part in SRMs produces most vibrations. Therefore, the geometric design of the stator is necessary to reduce the vibration. The free and forced vibrations for four different stator yoke structures are analyzed by the electromagnetic and structural Finite Element Method (FEM). Then vibration stator structure that offers less is proposed. The modal analysis results of a tested motor are compared with measurements.

• Proceedings of the KIEE Conference
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• 2002.07c
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• pp.1422-1424
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• 2002

EVA-OH (Ethylene-vinyl acetate-vinyl alchol terpolymers) were prepared by using the transesterification reaction between ethylene-vinyl acetate copolymer and alchol. Structural and thermal analyses were accomplished with FTIR and DSC. Space charge behaviors of EVA-OH were investigated using PEA method. Electrical conduction currents were also measured. As the increase of conversion rate, melting point increased and we could observe changes in space charge distributions and the increase of electrical conduction currents of EVA-OH.

• Elastomers and Composites
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• v.51 no.2
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• pp.99-105
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• 2016

Alkoxy modified silicone (PAMS) was synthesized from hydroxyl-terminated polydimethylsiloxane (OH-PDMS) and vinyltrimethoxysilane (VTMO) under alkali catalyst (NaOH and KOH) at room temperature ($25^{\circ}C$) via condensation polymerization. Then, the structural verification of the synthesized PAMS was confirmed using $^1H$-NMR and FT-IR spectroscopy. The reaction rate of PAMSs was studied in terms of the concentration variation of alkali catalyst. The reaction rate increased with the concentration of alkali catalyst, but no correlation between conversion and concentration of alkali catalyst was observed.