• Earthquakes and Structures
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• 제16권5호
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• pp.547-561
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• 2019

In this work, a new analytical approach using a theory of a high order hyperbolic shear deformation theory (HSDT) has been developed to study the free vibration of plates of functionally graduated material (FGM). This theory takes into account the effect of stretching the thickness. In contrast to other conventional shear deformation theories, the present work includes a new displacement field that introduces indeterminate integral variables. During the manufacturing process of these plates defects can appear as porosity. The latter can question and modify the global behavior of such plates. The materials constituting the plate are assumed to be gradually variable in the direction of height according to a simple power law distribution in terms of the volume fractions of the constituents. The motion equations are derived by the Hamilton principle. Analytical solutions for free vibration analysis are obtained for simply supported plates. The effects of stretching, the porosity parameter, the power law index and the length / thickness ratio on the fundamental frequencies of the FGM plates are studied in detail.

• Nuclear Engineering and Technology
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• 제54권4호
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• pp.1464-1470
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• 2022

This paper presents a high performance burnable absorber named as CIMBA (Cylindrically Inserted and Mechanically Separated Burnable Absorber) for the soluble-boron-free SMR. The CIMBA is the cylindrical gadolinia inserted into the annular fuel pellets. Although the CIMBA utilizes the spatial self-shielding effect of the fuel material, a large reactivity upswing occurs when the gadolinia is depleted. To minimize the reactivity swing of the CIMBA-loaded FA, two approaches were investigated. One is controlling the spatial self-shielding effect of the CIMBA as burnup proceeds by a multi-layered structure of the CIMBA (ML-CIMBA) and the other is the mixed-loading of two different types of CIMBA (MIX-CIMBA). Both approaches show promising performances to minimize the reactivity swing, where the MIX-CIMBA is more preferable due to its simpler fabrication process. In conclusion, the MIX-CIMBA is expected to accelerate the commercialization of the CIMBA and can be used to achieve an optimal soluble-boron-free SMR core design.

• The Journal of Asian Finance, Economics and Business
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• 제9권5호
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• pp.507-518
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• 2022

This study aimed to measure the monetary and non-monetary effects on brand awareness at hypermarkets in Riyadh. The independent variable consists of three sub-variables: price reductions, free samples, and purchasing vouchers. The research population has all Saudi and non-Saudi buyers in Riyadh. The figures show that the population size reached 3.87 million in 2019. The proportional stratification sampling technique and the recommended sample size were 387 buyers. The five-point Likert scale with the fully structured questionnaire was used. The study concldes the effect of free samples on brand awareness while there was no effect of monetary instruments. The results show that the three sales promotion incentives (price reduction, free samples, and purchasing vouchers) moderately affected brand awareness and a key role in explaining consumer behavior, so the significant impact was proved. In summary, this study showed that price reductions have the power of creating the perception of buyers at hypermarkets in Riyadh. Non-cash instruments were more effective than cash instruments in enhancing brand awareness at the hypermarkets in the Saudi market. So, the price reductions and purchasing vouchers have less power in conducting communication-based awareness. Building awareness and improving brand image through free samples were most visible in communication strategy.

• KIEE International Transaction on Electrical Machinery and Energy Conversion Systems
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• 제4B권4호
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• pp.180-183
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• 2004

This paper presents a description of the point collocation method and its application to the electromagnetic field computation. The interpolation scheme is based on the fast moving least square reproducing kernel approximation. In the method, the integration cell is not required and the essential boundary conditions can be enforced directly. Numerical simulations on 1-D and 2-D problems are carried out to validate the method. It is found that computational efficiency is higher than the general mesh-free methods.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2005년도 ICCAS
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• pp.1322-1327
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• 2005

This paper presents a single-stage ZVT full-bridge AC/DC converter for aerospace applications. The detailed operating principle and design consideration of this soft-switched converter are analyzed and described. The proposed circuit topology and control scheme are proposed to exhibit optimum performances (i.e. high power factor, high efficiency, ring-free and low EMI features). A laboratory prototype, 500W 5V/100A AC/DC converter was implemented. The simulation and experimental waveforms verify the feasibility of the proposed design.

• 제어로봇시스템학회논문지
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• 제4권4호
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• pp.543-550
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• 1998

From the power plant in a steel plant, environment pollutants such as $SO_x$, $NO_x$, CO and $CO_2$ are emitted by combustion reactions of the fuels which are by-product gases, oil and liquefied natural gas(LNG). To reduce the amounts of the pollutants, it is important to build a predictive model for the emission of the pollutants. In this paper, model that predict the amounts of generated pollutants for the used fuel is developed by using Gibbs free energy minimization method[1] with the temperature correction technique. For some data set, the calculation results from this model are compared with the real emission amounts of $SO_x$, $NO_x$, and the result of the calculation by both ASPEN PLUS which is a commercial simulation software. This model shows good results and can be applied to other power plants.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2006년도 제37회 하계학술대회 논문집 C
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• pp.1659-1660
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• 2006

After end of the 20th environmental problem was became issue. So about mercury free lighting sources are being studied very much. In this paper, a mercury and electrode free bulb was designed. in this bulb was injected mixed of Xe, Ne and Kr Gases. and then the bulb was discharged by 13.56MHz RF Power after spectrum, color coordinates and brightness were measured by spectrum meter CS-1000. Measured results were compared and analyzed, also analysis was able to do a characteristic of a gas defensive fight in proportion to a mixing ratio. Therefore the most of high brightness which was 4500cd/m2 was gained in 1:1 ratio of Xe:Ne at 60W input power.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2006년도 추계학술대회 논문집 광주전남지부
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• pp.43-47
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• 2006

In this paper, parameters of electron temperature and density for the mercury-free lighting-source were measured to diagnosis and analyze in Xe based inductively coupled plasma (ICP). As results at several dependences of 20~100mTorr Xenon pressure, the brightness of discharge tube was higher (4,900 $cd/m^2$) than other conditions when Xe pressure was 20mTorr and RF power was 200W. In that case, the electron temperature and density were 3.58eV and $3.56{\times}10^{12}cm^2$, respectively. The key parameters of Xe based ICP depended on Xe pressure more than RF power that could be verified. A high electron temperature and low electron density with a suitable Xe pressure are indispensible parameters for Xe based ICP lighting-source.

• Archives of Plastic Surgery
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• 제35권5호
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• pp.527-532
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• 2008

Purpose: Transverse type or volar oblique type of defect of thumb tip can be covered by Moberg flap or second toe pulp free flap. We compared these two methods in functional result, patients' satisfaction, and sensation, etc. to find a better way to cover the defect of the thumb tip. Methods: From 2003 to 2006, we chose the patients randomly with preoperative pictures. The patients had the defect of the thumb tip which is either transverse or volar oblique type. The 6 patients were treated with Moberg flap and other 6 patients were treated with second toe pulp free flap. We have analyzed the results by 2 point discrimination, side pinching power test, pulp to pulp pinching power test, pain scales (visual analogue scale), satisfaction scales of the patients (functional and aesthetic), the degree of the range of motion, etc. Results: All flaps survived without any complications. In the cases of Moberg flaps, the value of static 2 point discrimination test was 5.6 mm, and the value of moving 2 point discrimination test was 4.8 mm. In the cases of second toe pulp free flaps, the values were 9.6 mm and 9.3 mm. In the cases of Moberg flaps, the value of the Side pinch power test was 6.6 kg, 4.4 kg. In the case of second toe pulp free flaps, the values were 4.8 kg and 2.5 kg. The value of aesthetic satisfaction scale of the patients in Moberg flaps was 5.6, the value of functional satisfaction scale of the patients was 3.6. In cases of second toe pulp free flaps, the values were 5.6 and 3.6. The active range of motion of Interphalangeal joint in the cases of Moberg flaps was 46.6 degree, and the active range of motion of metacarpophalangeal joint was 55 degree, in the cases of second toe pulp free flaps, the values were 36.6 degree and 59 degree. Conclusion: As a result, when the defect of the thumb tip is transverse or volar oblique type, we suggest that the operators choose Moberg flap to cover the defect of the thumb tip.

• Journal of Welding and Joining
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• 제11권1호
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• pp.52-61
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• 1993

Laser welding of ASTM no. 1060 Al plate with a pulsed Nd: YAG laser of 200W average power was performed for end capping of KMRR nuclear fuel elements In this research, we performed basic welding experiments. Firstly, laser output parameters which affect laser welding parameters were studied by changing laser input parameters for effective welding of 1060 Al plates. We found that laser power density and pulse energy are important parameters for smooth bead shape. Secondly, welding parameters which affect weld width-to-depth ratio were studied by changing power density and pulse energy, shielding gas, and defocusing. We found that power density must be higher than 0.3 Mw/cm$^{2}$ pulse energy must be higer than 3 J. travel speed must not exceed 200mm/sec, laser focus must be existed beneath 2-3mm from plate surface and helium is proper shielding gas. Thirdly, we studied the weld defects of Al-1060 such as crack and porosity in lap-joint welding. We designed new welding geometry for crack free welding of Al-1060 plates, and obtained crack free weldment but with lack of fusion. However, with Ti, Zr grain refiner elements, we can weld Al plates without solidification hot crack. Finally, we studied the origin of porosity by changing shielding gas. And we found that porosity was resulted from entrapment of shielding gas by the collapsing keyhole.