• Applied Science and Convergence Technology
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• v.24 no.5
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• pp.125-131
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• 2015

We investigated the thermal characteristics of rotating anode X-ray tube to develop it for digital radiography by using computer simulation. The target which is the area of the anode struck by electrons is the most important component to get a long life of X-ray tube. So we analyze the thermal characteristics of the target and rotor assembly according to their emissivity by using ANSYS transient thermal simulation and then compare with the measured data of the target temperature operating in aging process of X-ray tube. Especially, keeping the lead coated layer as the role of metal lubricant on ball bearing enables to prevent the noise in rotating anode. The simulation result showed that its temperature was under the melting point of the lead in X-ray tube for digital radiography with 1.2 mm large focal spot 0.6 mm small focal spot and 150 kV tube voltage. We also investigated the relationship between the diameter of the anode shaft and the temperature of the anode and rotor assembly. It has been confirmed that the smaller anode shaft could be good for the rotor thermal characteristics.

• 한국신재생에너지학회:학술대회논문집
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• 2010.11a
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• pp.82.1-82.1
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• 2010

Recently, Molten carbonate fuel cells(MCFCs) have been developing to get a good durability and economic feasibility for commercialization. To achieve these objectives, the cost of nickel based electrodes should be reduced. Regular anode thickness used in MCFCs is normally 0.7mm. Thus, in our study, the purpose was to reduce anode thickness up to 0.3 mm keeping MCFC performance on standard levels. In-situ sintering has been used, with 2 different fabrication methods (method A and B) and 2 different supports (support 1 and 2). Voltage losses at different temperature (600,620,640,$650^{\circ}C$) and after 1000 hours showed the higher performance that can be obtained using method B and support 2. After single cell test, an open-circuit voltage(OCV) of 1.075 V and a closed-circuit voltage(CCV) of 0.829V were obtained, at current density of $150mV/cm^2$. Also the voltage loss ratio at different cell temperature was lower in the case of method B and support 2. According to these results, the cost of anode fabrication can be reduced in the future, contributing for the economical feasibility of MCFCs.

• 한국신재생에너지학회:학술대회논문집
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• 2011.05a
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• pp.200.2-200.2
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• 2011

This study was carried out in order to estimate the greenhouse performance for Ground filtration water source heat pump which was installed for supplying the heat to the paprika greenhouse in Jinju city. Experimental area of Greenhouse was $3,300m^2$, For keeping the heat from greenhouse, single plastic covering and double thermal screen was installed. With considering all of greenhouse insulation condition and designed heatng temperature, heating capacity for experimental greenhouse was calculated as 320,000kcal/hr. Coefficient of performance(COP) of Ground filtration water source heat pump was gauged and greenhouse heating performance was tested from Febuary 1 to Febuary 28 in 2011. The result showed that COP of heat pump was in the range of 3.7~4.7 and COP of heating system was in the range of 3.0~3.5. The vaule of COP was very high and the temperature inside greenhouse was well corresponded to the setting temperature of greenhouse environment controlling system. lots of Ground filtration water made the the number of well fewer and the expense for installing heating system cheaper than that of geothermal system used custmarily. and this system went beyond the limitation of intaking amount of groundwater in normal Groundwater source heat pump.

• Journal of Nutrition and Health
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• v.19 no.1
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• pp.3-15
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• 1986

This study was intended to investigate the rheological properties of the development formula of infant foods and the results are summarized as follow ; 1) Consistency of starch solutions measured by Brabender Anylograph and Brookfield viscometer showed that waxy rice and riece with malt had lower consistency and more rheological stability.The flow type of tested raw materials and formula was found to ？ pseudoplastic, as judged by n-value of 0.332 -0.692, and no yield value. 2) The influenced of temperature on consistency could be accounted for by the equation, In (n) = K(1/T) + const. this relationship indicated that consistency of tested sample increased as temperature decreased. The consistency of waxy rice, rice with malt and formula A were less affected by the temperature change. 3) Infant foods with malt(formula A ) ad with waxy rice maintained better freeze-thaw stability in terms of consistency and starch aggregation indicating that this infant food could be stored for a long term in the freezer section of the home refrigeratory without adverse effect on the product quality. 4) From the above experiments, it would necessarily follow that infant food can be easily made at home the food-stuffs generally available around us, and that the easiest and safest way to store them lies in making them into semisolid state, and in keeping them in frozen state.

• Journal of Industrial Technology
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• v.3
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• pp.87-94
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• 1983

Heating characteristics of red pepper paste packed in report pouches of various thicknesses and their storage stability were investigated to determine the adequate processing conditions that good bacteriological safty and minimal quality changes could be obtained, when sterilized by using a steam-air system retort. A heat penetration into pouch-packed red pepper paste was carried out through by a conductive heat transfer, indicating a simple logarithmic heating curve, and the smaller thickness revealed the higher heat penetration rate, suggesting the possibility of high temperature-short time sterilization of red pepper paste. The processing conditions with Fo-value of 4.5 or higher were sufficient for keeping up bacterial safty, but based on C-value, better quality retention was obtained at pouch thickness of 15mm under the processing temperature of $120^{\circ}C$. Subsequent storage study revealed that the red pepper paste packed in 15mm and processed at $120^{\circ}C$ with Fo=4.5 could be held without any spoilage and overall acceptance change, when stored for 6 months at room temperature under the relative humidity of 70%. After 3 months storage in $38^{\circ}C$ under saturation humidity, overall acceptance of red pepper paste were judged not to be maintainable on the acceptable level, but it may be suggested that above the results could be kept up a desirable quality without any remarkable deterioration.

• Progress in Superconductivity and Cryogenics
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• v.6 no.2
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• pp.46-51
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• 2004

This paper presents the results of a series of performance and reliability tests for the Stirling cryocooler. Infrared sensor systems incorporating cryocoolers are required to be qualified to the appropriate specification for the performance and reliability. FPFD Stirling cryocooler is currently under development for cooling infrared detector. Manufactured Stirling cryocooler delivers approximately 0.9W cooling at 80K for 30W∼40W of input power. It takes approximately 2 minutes to cool down to 80K at the ambient temperature of 23$^{\circ}C$. Performance characteristics for the vibration, acoustic noise, EMI and leak rate of the Stirling cryocooler are evaluated. We performed low and high temperature keeping test from -32$^{\circ}C$ to +52$^{\circ}C$ and operating test at high and low temperature cyclic range with acceptance tests performed at scheduled intervals. Cooling capacity is determined as a function of the temperatures at the compressor, hot end and cold tip at the expander. Finally, we describe the experimental facility for the MTTF evaluation and some typical results of the Stirling cryocooler.

• Journal of Electrical Engineering and Technology
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• v.10 no.3
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• pp.1383-1388
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• 2015

Proportional integral derivative (PID) control is one of the conventional control strategies. Industrial PID control has many options, tools, and parameters for dealing with the wide spectrum of difficulties and opportunities in manufacturing plants. It has a simple control structure that is easy to understand and relatively easy to tune. Injection mold is warming up to the idea of cycling the tool surface temperature during the molding cycle rather than keeping it constant. This “heating and cooling” process has rapidly gained popularity abroad. However, it has discovered that raising the mold wall temperature above the resin’s glass-transition or crystalline melting temperature during the filling stage is followed by rapid cooling and improved product performance in applications from automotive to packaging to optics. In previous studies, optimization methods were mainly selected on the basis of the subjective experience. Appropriate techniques are necessary to optimize the cooling channels for the injection mold. In this study, a digital signal processor (DSP)-based PID control system is applied to injection molding machines. The main aim of this study is to optimize the control of the proposed structure, including a digital PID control method with a DSP chip in the injection molding machine.

• The Journal of Korean Society of Virology
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• v.29 no.4
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• pp.211-219
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• 1999

Most of the currently licensed viral and bacterial vaccines produced in the world are in state of antigen suspension and the immunogenicity of vaccines could be maintained for one or two years only by keeping in the refrigerator, but without refrigeration vaccines would easily lose their immunogenicites. In this study, as a step to develope the method of increasing the stability of vaccines and maintaining the immunogenicity of vaccines for a long time at room temperature or higher temperature, trehalose, glucose and lactose at different concentration were added into the Hantaan virus vaccines and then kept at $37^{\circ}C$ for 12, 24, 48 hours and at room temperature for seven days respectively. Treated vaccines were then inoculated respectively into ICR mice and the titers of antibody against the antigen of Hantaan virus from the mice sera were evaluated. Vaccine without sugar lost immunogenicity completely in 24 hour at $37^{\circ}C$, but the vaccines containing trehalose could maintain some of the immunogenicity even after exposure at $37^{\circ}C$ for 48 hours and the best concentration of trehalose for maintaining the immunogenicities of vaccines was $7.5{\sim}10$ percent. The results suggest that addition of trehalose could increase the stability of Hantaan virus vaccine.

• Proceedings of the Korea Institute of Convergence Signal Processing
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• 2001.06a
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• pp.189-192
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• 2001

In this paper, we desire to design real time image processing system to change a various chromaticity in HDTV that has 1344*806 resolution and requires a high-speed 65MHz operation. In order to change the image chromaticity, it is necessary to calculate the color temperature of the image. Conventional way of calculating the temperature uses 2-D algorithm [1] that requires bulky hardware. This paper propose a one-dimensional color-temperature conversion that reduces the hardware complexity while keeping the performance of the 2-D algorithm. The proposed method is realized by using the Xilinx Virtex FPGA XCV 2000E-6BG560.

• The Transactions of the Korean Institute of Electrical Engineers C
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• v.49 no.7
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• pp.418-423
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• 2000

The fiber Fabry-Perot interferometric(FFPI) sensor is well known in the field of industrial diagnosis due to its outstanding properties such as tiny size, simple and rugged structure, and easy interrogation. As other fiber interferometric sensors, it also suffers from ambiguous output caused by highly periodic feature in its optical transfer function. In most cases, the ambiguity leads to relatively short dynamic operating range and long processing time during power-on reset, which limits its application to some specific fields requiring very high resolution. In this paper a method based on double sensing scheme was proposed to overcome the above difficulty. By employing a fringe selection auxiliary FFPI sensor the original FFPI sensor can identify its true position on the phase domain. The performance test with 10mm FFPI sensor and a thermocouple temperature sensor for reference shows wide dynamic range 0-900$\ell$ keeping a reasonable resolution of 0.1$\ell$ over the entire range.