• Journal of the Korean Institute of Telematics and Electronics A
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• v.32A no.1
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• pp.138-145
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• 1995

The offset voltage in silicon Hall plates is mainly caused by stress and strain in package, and by alignment in process. The offset voltage is appeared random for condition change with time in the factory, is non-linearly changed with temperature. In this paper proposed new method of design of Hall IC, and methematicaly proved relation layout of chip of 90$^{\circ}$-shift-current Hall plate pair is matched with "Differentail to single ended Conversion amplifier." In the experiment, the offset voltage is reduced about 1/100 time than the original offset voltage.

• Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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• 2000.11a
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• pp.186-192
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• 2000

The heat generated in contact type braking system can cause an unacceptable braking performance. Thermal behavior of ventilated disk brake system is presented in this paper. The temperature and velocity fields of 3-D unsteady simulated model are obtained using a software package "FLUENT". The numerical results show that there exits a temperature nonuniformity between the disk faces contacting with pads. The conduction rate through the disk and pad is calculated and the effect of material conductivity is also investigated.estigated.

• Tribology and Lubricants
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• v.28 no.2
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• pp.81-92
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• 2012

To product multi-grade oil like engine oil, a sort of mineral base oil is mixed with a fundamental additive liquid package and a polymer liquid as viscosity index improver in order to improve the lubricating property of oil. That is, engine oil is the mixture of more than two fluids. In this paper, it will be systematically organized the governing equation describing non-Newtonian thermo-hydrodynamic lubrication related with the mixture of incompressible fluids based on the principle of continuum mechanics. Then, in order to find how the thermal analysis effect on the bearing performance lubricated with the mixture of multi-fluids, it will be compared to the performances between the mixture of each liquid to be blended and multi-grade engine oil as a single fluid in a high speed journal bearing. It is found that, in the case of lower viscosity oil, the difference of pressure distribution between the above two cases turns out to be existed, even if the load capacity is same level.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• v.y2005m4
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• pp.377-380
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• 2005

A study of ignition characteristics of cracked JP-7 fuel with both oxygen and air has been conducted over a wide range of pressures (1-20 atm), temperatures (1200-2000 K), and equivalence ratios (0.5-1.5). Correlations of ignition delay, of the form, $\tau=Aexp(E/RT)[F]^{a}[O_2]^{b}$ are established using the Chemkin-II package and least square analysis. The effect of $C_3$ hydrocarbons in cracked JP-7 fuel is examined by comparing the ignition delays for two different cracked compositions. A comparison for ignition delay is also made with the experimental results obtained by injecting liquid JP-7 fuel in air using a shock tube apparatus.

• Journal of the Korean Society for Precision Engineering
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• v.27 no.1
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• pp.91-98
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• 2010

The increasing of power and processing speed and miniaturization of central processor unit (CPU) used in electronics equipment requires better performing thermal management systems. A typical thermal management package consists of thermal interfaces, heat dissipaters, and external cooling systems. There have been a number of experimental techniques and procedures for estimating thermal conductivity of thin, compressible thermal interface material (TIM). The TIM performance is affected by many factors and thus TIM should be evaluated under specified application conditions. In compact packaging of electronic equipment the chip is interfaced with a thin heat spreader. As the package is made thinner, the coupling between heat flow through TIM and that in the heat spreader becomes stronger. Thus, a TIM characterization system for considering the heat spreader effect is proposed and demonstrated in detail in this paper. The TIM test apparatus developed based on ASTM D-5470 standard for thermal interface resistance measurement of high performance TIM, including the precise measurement of changes in in-situ materials thickness. Thermal impedances are measured and compared for different directions of heat dissipation. The measurement of the TIM under the practical conditions can thus be used as the thermal criteria for the TIM selection.

• Korean Journal of Food Science and Technology
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• v.26 no.6
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• pp.713-717
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• 1994

Effects of packing materials on the gas compositions in package of fresh peeled garlic (Allium sativum L.) were investigated. The fresh peeled garlics packed in $20,\;40,\;60\;{\mu}m$ LDPE and $30\;{\mu}m$ HDPE pouches were stored at $20^{\circ}C$, 76% RH. The variables including respiration characteristics, gas compositions, general appearance, and film permeabilities to $O_2$, $CO_2$ and $H_2O$ vapor were measured. A model was evaluated for the prediction of $O_2$ and $CO_2$ equilibrium concentrations inside packages and for the optimization of packaging parameters. Experimental and simulated gas composition results were found to be in good agreement. The $30\;{\mu}m$ HDPE pouch with 4% $O_2$ and 7.5%$CO_2$ equilibrium concentrations conferred the best appearance of peeled garlic, giving 6 days of storage life. As a result, MA seemed to have a beneficial effect on appearance of fresh peeled garlic, possibly due to reduced microbial activity.

• Korean Journal of Human Ecology
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• v.15 no.6
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• pp.1025-1035
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• 2006

Brand Relationship Quality(BRQ) reflects the intensity and viability of the enduring association between a consumer and a brand so it is assumed to be the indicator which can affect brand performance such as brand satisfaction, brand attitude, and brand loyalty. The purpose of this study is to analyze the structural equation model showing the path between BRQ and brand performance. The subjects were women in their 20s to 40s living in Seoul and other metropolitan areas. 482 copies of questionnaire were analyzed by reliability, Pearson's correlation analysis, confirmatory factor analysis using SPSS 11.0 Package and AMOS 5.0 Package. The results showed that BRQ had positive influence on the brand performance-brand satisfaction, brand attitude, brand loyalty. As for the total effect about brand loyalty, BRQ was the most influential variable compared with other variables- brand satisfaction, brand attitude. The indirect impact of BRQ on brand loyalty is bigger than the direct impact of BRQ and brand satisfaction emerged as the important intermediate variable between BRQ and brand loyalty. Therefore, effective marketing strategy can be accomplished according to differential impact of the BRQ facets to induce consumer's satisfaction, which can lead to brand loyalty.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.22 no.4
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• pp.121-129
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• 2008

This paper deals with the design of BLDC motor replacing ferrite magnet with rare earth magnet. Electric machinery system using ferrite magnet motor is already widespread in large numbers. Electrical appliance makers have a tendency to adhere to existing system using ferrite magnet motors because of redesigning the whole system. This paper designs the rare earth magnet motor untouching the external system dimension and motor outer size. To do the design simply, finite element package is used iteratively To reduce the cogging torque effect and magnetic saturation, stator yoke shape and the groove of the end face of yoke are redesigned.

• Journal of the Korean Society for Precision Engineering
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• v.31 no.10
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• pp.857-863
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• 2014

In this work, we introduce various bonding technologies for 3D package and suggest Insert-Bump bonding (ISB) process newly to stack multi-layer chips successively. Microstructure of Insert-Bump bonding (ISB) specimens is investigated with respect to bonding parameters. Through experiments, we study on find optimal bonding conditions such as bonding temperature and bonding pressure and also evaluate in the case of fluxing and no-fluxing condition. Although no-fluxing bonding process is applied to ISB bonding process, good bonding interface at $270^{\circ}C$ is formed due to the effect of oxide layer breakage.

• International Journal of Internet, Broadcasting and Communication
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• v.7 no.2
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• pp.130-136
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• 2015

In this paper, we analyzed the adjacent channel interference of the LTE band 40 defined by 3GPP on the WLAN system based on the Monte-Carlo method, and found the guard band required for compatibility between the two systems. This study have a difference compared to the previous studies about cell radius was determined using Extended Hata Model considering practical environment, interference protection distance related to guard band, and the spectrum emission mask improvement effect for minimizing the interference. Simulation results, for no channel interference compatibility of LTE and WLAN for mobile satellite wireless package system, we can find the need 15MHz guard band at specified spectrum emission mask and 10MHz guard band at assumed spectrum emission mask.