• Journal of the Korean Society of Food Science and Nutrition
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• v.21 no.4
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• pp.390-397
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• 1992

This study was carried out to analyze the physicochemical properties of bovine milks, which were heated with LTLT, HTST, UHT pasteurization and UHT sterilization methods and to compare the heat intensity among the heating methods and samples. The mean HMF values per liter milk were measured as 0.66~1.62 $\mu$M (LTLT), 0.9~1.78$\mu$M (HTST), 3.53$\mu$M(UHT pasteurized) and 7.43~8.97$\mu$M (UHT sterilized) in samples, re- sportively. The available Iysine contents per 100ml milk showed 293.2 mg (Raw), 289.2~291.2 mg (LTLT), 298.4~292.4mg (HTST), 272.4~261.6mg (UHT pasteurized) and 279.0mg (UHT sterilized), respectively. The rates of whey protein denaturation were 9.5~11.4% (LTLT), 9.5~17.1% (HTST), 89.3~95% (UHT pas-tsterilized) and 62.7% (UHT sterilized), respectively. The contents of SH groups per g protein were determined as 2.86$\mu$M (Raw) and 2.95~3.15$\mu$M (LTLT), 3.08~3.18$\mu$M (HTST), 3.26~3.42$\mu$M (UHT Pasteurized) and 3. 36$\mu$M (UHT sterilized), respectively, The SS groups Contents per g protein were 28.93$\mu$M (Raw), 25.72~26. 51 $\mu$M (LTLT), 26.93~26.79$\mu$M (HTST), 23.65~23.04 $\mu$M (UHT pasteurized) and 24.69$\mu$M (UHT sterilized), respectively. The ascorbic acid contents per liter milk were measured 6.05mg (Raw), 1.47~1.65mg (LTLT), 2.50~3.85mg (HTST), 2.87~3.69mg (UHT pasteurized) and 4.50mg (UHT sterilized). The changes of some in-dices in milk samples depend on the heating temperature and time ; the HMF values, SH groups, whey protein denaturation rates increased, while the available lysine contents and SS groups decreased in LTLT, HTST, UHT pasteurized and UHT sterilized milks. No remarkable differences were found in heating indicators between LTLT and UHT milks.

• Proceedings of the Korean Society for Information Management Conference
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• 2013.08a
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• pp.7-10
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• 2013

본 연구는 2005년부터 2013년 3월까지 Scopus에서 페미니즘 분야를 선정하여 이에 해당하는 논문 37편과 이 논문들이 인용한 유튜브 55개를 대상으로 학술논문들이 유튜브를 인용할 때 활용하는 유형과 문제점을 살펴보고 참고문헌으로서 유튜브의 표기사항에 영향을 미치는 요인을 분석하였다. 연구 의도를 효율적으로 보여주는 유튜브는 0.34%의 인용률을 나타내고 있으며 지속적으로 인용이 증가하고 있다. 그러나 유튜브 접속오류는 55개중 6개(10.9%)이며, 참고문헌으로서 유튜브의 표기가 부적합하게 기재된 경우는 38개(69.1%)였다. 그 원인으로 올바르게 표기하지 않은 저자의 노력 부족과 인용된 유튜브가 학술정보로서 충분한 정보를 제공하지 못한 경우가 중요한 요인으로 나타났다.

• Proceedings of the Korean Society of Computer Information Conference
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• 2022.07a
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• pp.195-197
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• 2022

일반적으로 게임에서는 유저의 과금이나 광고 시청 등으로 수익을 내기 때문에 게임을 플레이 하는 유저의 수는 곧 그 게임의 수익으로 이어진다. 그러므로 신규 유저의 유입뿐만 아니라 기존 유저의 이탈을 막는 것 또한 매우 중요하다. 유저의 이탈은 짧은 기간 동안 게임을 플레이 한 유저인지 아니면 매우 오래 플레이하고 과금까지 하던 충성고객인지를 가리지 않고 일어난다. 본 논문은 설문을 통해 온라인과 모바일 게임에서 유저의 이탈 경험과 이탈 원인에 대해서 조사하고 이에 따른 유저의 이탈 예방과 개선 방안을 제시한다.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.22 no.3
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• pp.415-421
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• 2021

This study analyzed the effect on the cooling performance of the channel shape of a heat sink for an insulated gate bipolar transistor (IGBT). A serpentine channel was used for this analysis, and the parameter for the analysis was the number of curves. The analysis was conducted using computational fluid dynamics with the commercial software ANSYS fluent. One curve in the channel improved the heat dissipation performance of the heat sink by up to 8% compared to a straight-channel heat sink. However, two curves in the channel could not improve the heat discharge performance further. Instead, the two curves caused a higher pressure drop, which induces parasitic loss for the pumping of coolant. The pressure drop of the two-curve channel case was 2.48-2.55 times larger than that of a one-curve channel. This higher pressure drop decreased the heat discharge efficiency of the heat sink with two curves. The discharge heat per unit pressure drop was calculated, and the result of the straight heat sink was highest among the analyzed cases. This means that the heat discharge efficiency of the straight heat sink is the highest.

• Journal of Adhesion and Interface
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• v.3 no.2
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• pp.1-8
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• 2002

Polyurethane NCO prepolymers were synthesized with the polyols such as PTMG, GP and the isocyanate such as TDI at $40^{\circ}C$ for 8.5 minutes. As average molecular weights (${\bar{M_n}}$: 1000, 2000, 3000, 4000) of PTMG, and GP were decreased from 4000 to 1000, ratio of oil gelation increased from 298%, to 440%, for Bunker B. When oil and water were emulsified, the ratio of gelation was increased approximately two times. Ratio of gelation for emulsive Bunker B was increased from 402% to 910%, for PTMG1000 and increased from 440%, W 958% for GPI1000. Ratio of oil gelation for emulsive Bunk C which has higher viscosity than Bunker B was measured w 923% for PTMG1000 made with chain extender, i.e. EG, and measured to 1098% for GP1000. The gel made from GP which has three functional group showed soft and strong characteristic, as a result, it can be removed easily from oil spilled ocean.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.13 no.5
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• pp.173-181
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• 1993

Under natural conditions, rivers do not in general take straight courses but instead take winding courses. This is known as meandering of rivers. Meandering of rivers are so complicated because of the mutual interactions between flow and movable boundaries. In quantitative information, it is important to predict the future location of a river channel(channel migration) because in selecting a bridge site or a location of a road. It may be valuable to know the future impact of a nearby river on those structures. When the prediction model of the migration of channel is used in domestic rivers with high coefficient of river regime, it is rational to use the periodical dominant discharge (PDD), which is named firstly by the author, instead of the average discharge. According to the analysis of the erosion coefficient, the mean deviation on the channel migration, and the bed scour factor, it can bring shedding light on the fact that the discharge is one of the dominant components in channel migration. In project area, the discharge that can shift the channel is slightly greater than 6,000CMS. The prediction model of the migration of channel estimated the erosion coefficient, $E_0$ by the data from the South Han River. This estimated value from the South Han River was also used to predict the migration of the South Han River in year 2000.

• Korean Journal of Food Science and Technology
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• v.23 no.5
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• pp.568-571
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• 1991

This study was designed to select the most stable oil among vegetable oils for mayonnaise preparation on lipid oxidation when blended with perilla oil. Oxidative stabilities of perilla oil, soybean oil, rapeseed oil, corn oil, sunflower oil and perilla blended oils (blended perilla oil with other vegetable oil in a equal weight rate) were tested. Among the perilla blended oils, perilla blended soybean oil was the most effective on oxidative stability. This may be concerned with the fact that the content of natural antioxidant, tocopherol, is higher than that of other oils. Mayonnaise was prepared by using both perilla oil and perilla blended soybean oil. Variations of POV and tocopherol content of mayonnaise during storage at $37^{\circ}C$ were compared. The changes in POV and tocopherol content in the mayonnaise of perilla blended soybean oil were less than those of perilla oil. This result suggested that the usage of perilla blended soybean oil instead of perilla oil itself is possible in the manufacturing of mayonnaise.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.1
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• pp.470-476
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• 2019

The braking force for a train is generally provided by compressed air. The pressure valve system that is used to apply appropriate braking forces to trains has a complex flow circuit. It is possible to make a channel shape that can increase the flow efficiency by 3D printing. There are restrictions on the flow shape design when using general machining. Therefore, in this study, the compressed air flow was analyzed in a pressure valve system by comparing flow paths made with conventional manufacturing methods and 3D printing. An analysis was done to examine the curvature magnitude of the flow path, the diameter of the flow path, the magnitude of the inlet and reservoir pressure, and the initial temperature of the compressed air when the flow direction changes. The minimization of pressure loss and the uniformity of the flow characteristics influenced the braking efficiency. The curvilinear flow path made through 3D printing was advantageous for improving the braking efficiency compared to the rectangular shape manufactured by general machining.

• Journal of the Korea Convergence Society
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• v.13 no.3
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• pp.191-196
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• 2022

Unlike an international combustion engine car, a battery-powered electric vehicle requires an additional heat source for its heating system. A high-voltage coolant heater has the advantages of high efficiency and a wide operating temperature range. In its development, the geometry design of the coolant flow path is essential. This paper presents the thermal flow simulations of a 7kW high-voltage heater with symmetric serpentine flow channels arranged parallelly. The heater performance was evaluated from the simulation results in terms of the pressure and temperature differences and the flow uniformity. The proposed design showed a greater flow resistance and similar heat exchanging capability than the existing parallel serpentine design. It has the advantage of a relatively wide low-temperature surface area, where the control circuit board susceptible to high temperatures can be located.

• The Korean Journal of Food And Nutrition
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• v.15 no.4
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• pp.342-349
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• 2002

Rapeseed oil is easily oxidized due to the high contents of unsaturated fatty acid such as linoleic acid and linolenic acid. For stability of rapeseed oil oxidation, a special process is required. Two kind of simple and interesterifying mixed rapeseed oil were prepared according to add 30%, 50% and 70% of coconut oil and palm oil. Sample oils were heated at 180${\pm}$5$^{\circ}C$ for 5, 10, 15, 20, 25, 30 and 35 hours. Then the physicochemical properties such as the tendency of oxidation were investigated. The initial AV and POV of interesterifying mixed rapeseed oil were higher than those of simple mixed oil. But the tendency of oxidation were similar. While oxidation rate of similar and interesterifying mixed rapeseed oils with coconut oil and palm oil were lower about than those of rapeseed oil.