• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.10
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• pp.4757-4761
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• 2012

LED chip on board(COB) package has been fabricated using aluminum substrate and aluminum anodization process. An alumina layer, used as a dielectric in COB substrate, is produced on aluminum substrate by selective anodization process. Also, selective anodization process makes it possible to construct a thermal via with a fully-filled via hole. Two types of the COB package are fabricated in order to analyze the effects of their substrate types on thermal resistivity and luminous efficiency. The aluminum substrate with the thermal via shows more improved measurement results compared with the alumina substrate. These results demonstrate that selective anodization process and thermal via can increase heat dissipation of COB package in this work. In addition, it is proved experimentally that these parameters also can be enhanced using efficient layout of multiple chip in the COB package.

• Asian-Australasian Journal of Animal Sciences
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• v.6 no.3
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• pp.367-371
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• 1993

The feeding value of maize cob meal was investigated in a trial involving one hundred and forty Arbor Acre day-old chicks raised to eight weeks of age. The maize cob meal which contained 32.5% fibre, 2.5% protein and had a gross energy value of 2,550 kcal/kg, was incorporated into the experimental diets at either 0, 2.9, 5.8, 11.6 or 23.2% level. All diets were formulated to contain 3,200 kcal/kg of metabolizable energy and approximately 22% protein by varying the proportions of maize and whole cooked soyabean meal in the diets. The inclusion of maize cob meal up to 11.6% in the diet did not significantly (p>0.05) affect body weight gains, feed consumption and utilization, as well as carcass yield and dressing percentage. However, at the 23.2% level of maize cob meal inclusion, body weight gains, feed utilization and carcass yields were significantly (p<0.05) reduced. The use of maize cob meal reduced feed cost for raising birds and either maintained or improved gross profit returns with up to 11.6% level of inclusion in the diet. It was concluded that maize cob meal can be included up to 11.6% in the diet of broiler chickens provided dietary energy concentration is maintained at 3,200 kcal of metabolisable energy per kilogramme of feed by using high energy density feed ingredient such as boiled whole seed soyabean meal.

• The Journal of the Korea institute of electronic communication sciences
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• v.9 no.5
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• pp.561-566
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• 2014

The high power COB(Chip on Board) LED, densely arranged chips on a board, are increasing to resolve heat problems in LED that has luminous semiconductor chips as main materials. In case of high-power COB LED, protection against heat is necessary due to the power consumption is high. Also if the temperature of device increases, the optical emission becomes less efficient and the life rapidly reduces due to thermal stress. This study packaged 13.5W COB LED and heat sink with difference form and produced 13.5W COB LED down-light heat sink by analyzing the thermal modes with Solidworks Flow Simulation. And finally it analyzed and evaluated the thermal modes using contacting and non-contacting thermometers.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.18 no.2
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• pp.401-407
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• 2014

There are increasing interests in COB (Chip On Board) that densely arranged many LED chips on one board in order to solve the heat issue. There are many problems being on the rise: the lifespan decreases as the temperature of LED devices increases; Red Shift phenomenon, in which wave length of spectral line moves from original wave length to long wave length, occurs; and optical power decreases as $T_j$ increases. In order to resolve such problems, this study selected the optimum thickness and length of Fin, planned the second Heat sink that is optimum for COB LED with 15W, and analyzed thermal mode by Solid Works Flow Simulation through 15W COB packaging with the planned Heat sink. 15W COB down-light Heat sink that is produced based on this analysis was utilized to analyze thermal mode through contact thermometer and electrical properties through Kelthley 2430.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.7 no.1
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• pp.20-25
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• 2014

There are several severe problems for LED device, the next generation's economy green lighting: as the temperature increases, the lamp efficiency decreases; if the temperature is over $80^{\circ}C$, the lifetime of lighting decreases; Red Shift phenomenon that wavelength of spectrum line moves toward long wavelength occurs; and optical power decreases as $T_j$ increases. Thus, Heat sink design that can minimize the heat of LED device is currently in progress. While the thermal resistance of COB Type LED was reduced by direct coupling of LED chip to the board, residential 13.5W requires Heat sink in order resolve heat issue. This study designed Heat Sink suitable for residential 13.5W COB LED down-light and selected the optimum Fin thickness through flow simulation that packaged the designed Heat Sink and 13.5W COB. And finally it analyzed and evaluated the thermal modes using contacting thermometer.

• Journal of Forest and Environmental Science
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• v.37 no.1
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• pp.79-89
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• 2021

Cement bonded boards of 10 mm in thickness were produced from the mixture of Gmelina arborea sawdust and corn cob particles. The strength and dimensional stability of cement bonded composites produced from these two mixtures were examined. A total of thirty experimental boards were produced at density level of 1,000 kg/㎥ with cement to fibre ratio of 2.5:1 and 3:1 and five (5) blending proportions of G. arborea sawdust to corn cob particles of 100:0; 75:25; 50:50; 25:75 and 100:0. The effect of the cement to fibre ratio and blending proportion on the Water Absorption (WA), Thickness Swelling (TS), Modulus of Rupture (MOR), and Modulus of Elasticity (MOE) were determined. The result indicates that as the mixing ratio of cement to fibre and blending proportion of maize cob (75%) to G. arborea (25%) increased, the thickness swelling, water absorption decreased, whereas the MOR and MOE increased. It also shows that most dimensionally stable and flexural strength boards were produced at the highest level of mixing ratios (3:1) and blending proportion of G. arborea to corn cob 25:75. However, the analysis of variance shows that TS and WA were significantly different, whereas, MOE and MOR were not significantly affected by mixing ratios and blending proportions. Finding of this study has shown that maize cob particles are suitable for cement bonded board production.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.15 no.2
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• pp.147-155
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• 1993

The combined induction chemotherapy is usually used to treat the advanced head and neck cancer. In particular, it is considered that the COB(Cisplatin, Oncovin, Bleomycin)regimen is very effective against the squamous cell carcinoma in head and neck region. The purpose of this study is to evaluate the cancer tissue response to chemotherapy (COB Regimen) histopath ologically.

• Journal of the Microelectronics and Packaging Society
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• v.16 no.3
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• pp.25-29
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• 2009

High temperature high humidity and thermal shock reliability tests were performed for the board level COB(chip-on-board) flip chip packages using self-formulated and commercial NCPs(non-conductive pastes) to ensure the performance of NCP flip chip packages. It was considered that the more smaller fused silica filler in prototype NCPs is more favorable for high temperature high humidity reliability. The failure of NCP interconnection was affected by the expansion of epoxy due to moisture absorption rather than the fatigue due to thermal stress. It was considered that the NCP having more higher adhesive strength seems to be more favorable to increase the thermal shock reliability.

• Journal of Biosystems Engineering
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• v.14 no.1
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• pp.33-40
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• 1989

The flow properties of water added com-cob-mix(CCM) were studied in order to provide basic information for designing its pumping system. For the study, a model system similar to actual situation was constructed. From the experiment, it can be concluded that the flow properties of the water added CCM has close relationship with its moisture content as follows; 1. The pressure drop caused by friction was very low when the moisture content of water added CCM was more than 70%. However, when the moisture content of the material is about 60%, the pressure drop increases up to 10 kPa/m at low pumping speed, and 20 kPa/m at high pumping speed, respectively. 2. The water added CCM having about 65% moisture content showed pseudo-plastic flow characteristics. 3. As the moisture content of the material decreases, the shear stress increases more rapidly than the shear rate does. Finally, below approximately 60% moisture, the shear stress becomes a linear relationship with the shear rate. 4. It was possible to pump the material having the moisture content down to 58% through a pipe having 80 mm diameter by a pump operating at 234 rpm. However, by either increasing the diameter of the pipe or decreasing the pumping speed, it can be possible to pump the material having lower moisture content than 55%.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.49 no.2
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• pp.107-116
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• 2023

In this study, to explore the possibility of using discarded by-products of corn as a wrinkle-improving functional material, the active ingredient contained in each part including kernel, cob, husk, and silk of 10 varieties of chodang and waxy corn was identified and the content was analyzed to suggest the possibility of corn by-products as upcycling materials. As a result of evaluating the collagen synthesis efficacy of extracts by part, the cob in chodang and waxy corns showed significant activity at 100 ㎍/mL concentration of 176.5 and 140.0%, respectively. The LC-MS/MS qualitative analysis resulted in the identification of 18 components in the cob, of which N, N'-diferuloylputrescine (DFP) was selected as an active ingredient, and the quantitative analysis was conducted by variety and part. As a result, DFP was confirmed only in the cob and kernel, and it was most frequently detected in the cob of the Goldsugar of chodang corn (39.6 ㎍/g) and Daehakchal of waxy corn (38.4 ㎍/g). The cob is a by-product left over from grain removal, and is expected to create new added value as a material that promotes collagen synthesis. Through this study, we propose the possibility of using discarded cob as a wrinkle-improving functional material.