• Title/Summary/Keyword: Hot-Cold

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Deposition of Tungsten Thin Film on Silicon Surface by Low Pressure Chemical Vapor Deposition Method (저압 화학 기상 증착법을 이용한 실리콘 표면 위의 텅스텐 박막의 증착)

  • Kim, Seong Hun
    • Journal of the Korean Chemical Society
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    • v.38 no.7
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    • pp.473-479
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    • 1994
  • Tungsten thin film was deposited on p-(100) silicon substrate by using the LPCVD(low pressure chemical vapor deposition) technique. $WF_6$ was used as a source gas for tungsten and $SiH_4$ was used as a reducing gas for $WF_6$. Tungsten thin film was deposited by either SiH4 or Si substrate reduction of $WF_6$ under cold-wall condition and it was deposited by $SiH_4$ reduction of $WF_6$ under hot-wall condition. The crystal structure of deposited thin film under both conditions were identified to be bcc (body centered cubic). The physical and electrical properties of deposited thin films were investigated. The deposited film under hot-wall condition changed to $WSi_2$ film by the annealing under $800^{\circ}C.$ From the experimental results and theoretical considerations, the change of the crystal structure of the thin film by annealing was discussed. $WSi_2$ thin film, which was known to have good compatibility with Si substrate, could be produced under hot-wall condition although the film properties were superior under cold-wall condition.

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The Effects of Feet of Hot and Cold Therapy on Blood Flow Regulation and Blood Vessel Change

  • Kim Ho-Young
    • The Journal of Korean Physical Therapy
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    • v.14 no.2
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    • pp.32-50
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    • 2002
  • The 30 male and female patients of S-oriental medicine hospital which is located in Taegu, who don't have any caidiovascular diseases and skin diseases, agreed to the experiment for finding out the effects of hot and cold therapy. They were divided into 10 experimental groups, that is hot therapy group(experimental 1 group : 10 People), contrast therapy group(experimental 2 group : 10 People) and mustard hot therapy group (experimental 3 group : 10 People).

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Data carousel scheduling based on user-request statistics for Digital Multimedia Broadcast (DMB) (디지털 멀티미디어 방송(DMB)에서 클라이언트 요구 기반의 데이터 캐러셀 스케줄링)

  • Choi, Sujeong;Park, Ik-Hyun;Kang, Sang-Hyuk
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.31 no.2B
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    • pp.129-136
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    • 2006
  • We propose a new data carousel scheduling algorithm for on-demand data broadcasting in DMB. The server divides data items into two sets named hot and cold, according to request statistics from clients. When constructing a data carousel, hot items are placed periodically with their upper limit of broadcasting frequency. If there are empty slots after placing hot items, cold items with high request ratio are placed until the carousel is full. A cold item is broadcast only once in the caroulsel. For the response on clients' requests, our proposed scheme is shown to have high success ratio with short waiting time.

Effects of Hot Boning and Soy Sauce on the Processing Properties of Semi-dried Beef Jerky

  • Han, Doo-Jeong;Lee, Eui-Soo;Lee, Si-Kyung;Kim, Cheon-Jei
    • Food Science of Animal Resources
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    • v.31 no.4
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    • pp.497-505
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    • 2011
  • The objective of this study was to examine the effect of hot-boning and soy sauce as a curing agent on the processing properties of beef jerky. Beef jerky was prepared under the following four treatment conditions; Beef jerky with cold-boned beef and salt solution, beef jerky with cold-boned beef and soy sauce solution, beef jerky with hot-boned beef and salt solution, and beef jerky with hot-boned beef and soy sauce solution. Cured meat and jerky containing hot-boned beef had a significantly higher pH, water holding capacity (WHC), moisture content, Myofibrillar fragmentation index (MFI), processing yields, tenderness, and sensorial scores than samples containing cold-boned beef (p<0.05). Regardless of the raw materials, the jerky containing soy sauce had a significantly lower pH, WHC, moisture content, salt content, TBA, CIE $L^*$ and $b^*-$ values, and significantly higher MFI, mechanical tenderness, and sensorial scores (p<0.05). Based on these findings, we concluded that the use of hot-boned meat and soy sauce was the most effective boning method and curing agent during beef jerky processing.

A Compressed Hot-Cold Clustering to Improve Index Operation Performance of Flash Memory-SSD Systems (플래시메모리-SSD의 인덱스 연산 성능 향상을 위한 압축된 핫-콜드 클러스터링 기법)

  • Byun, Si-Woo
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.11 no.1
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    • pp.166-174
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    • 2010
  • SSDs are one of the best media to support portable and desktop computers' storage devices. Their features include non-volatility, low power consumption, and fast access time for read operations, which are sufficient to present flash memories as major database storage components for desktop and server computers. However, we need to improve traditional index management schemes based on B-Tree due to the relatively slow characteristics of flash memory operations, as compared to RAM memory. In order to achieve this goal, we propose a new index management scheme based on a compressed hot-cold clustering called CHC-Tree. CHC-Tree-based index management improves index operation performance by dividing index nodes into hot or cold segments and compressing pointers and keys in the index nodes and clustering the hot or cold segments. The offset compression techniques using unused free area in cold index node lead to reduce the number of slow erase operations in index node insert/delete processes. Simulation results show that our scheme significantly reduces the write and erase operation overheads, improving the index search performance of B-Tree by up to 26 percent, and the index update performance by up to 23 percent.

Dynamic Characteristics of an Unsteady Flow Through a Vortex Tube

  • Kim, Chang-Soo;Sohn, Chang-Hyun
    • Journal of Mechanical Science and Technology
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    • v.20 no.12
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    • pp.2209-2217
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    • 2006
  • Dynamic flow characteristics of a counter-flow vortex tube is investigated using hot-wire and piezoelectric transducer (PZT) measurements. The experimental study is conducted over a range of cold air outlet ratios (Y=0.3, 0.5, 0.7, and 1.0) and inlet pressure 0.15 MPa. Temperatures are measured at the cold air outlet and along the vortex tube wall. Hot-wire is located at cold outlet and PZT is installed at inner vortex tube by mounting at throttle valve. The cold outlet temperature results show that the swirl flow of vortex tube is not axisymmetric. The hot-wire and PZT results show that there exist two distinct kinds of frequency, low frequency periodic fluctuations and high frequency periodic fluctuations. It is found that the low frequency fluctuation is consistent with the Helmholtz frequency and the high frequency fluctuation is strongly related with precession oscillation.

Integration Forming Technology based on Cold Hot Forging of Clutch Jaw Parts for Farm Machinery (냉열간 단조기술을 적용한 농기계용 클러치 Jaw 부품 일체화 성형기술)

  • Park, Dong-Hwan;Han, Seong-Chul
    • Journal of the Korean Society of Manufacturing Technology Engineers
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    • v.24 no.5
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    • pp.489-495
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    • 2015
  • Forging is a manufacturing process involving the shaping of metal using localized compressive forces and the process of deforming metal into a predetermined shape using certain tools and press according to the temperature. Forging provides stronger metal parts than that possible by casting or machining. Conventional clutch jaw parts have been developed through cold forging and precision machining; however, fabrication of integral clutch jaw parts for farm machinery has not been reported yet. These parts were developed by applying a complex forging technology combining cold and hot forging. The integrated forming technology proposed in this study will be useful for reducing the lead-time for manufacturing, improving the accuracy of products, and eliminating the welding process.

A Study about Change in the Temperature by Each Region and Time After Hot & Cold Application (온.냉적용시 신체부위별 및 시간에 따른 체온변화에 대한 연구)

  • Kim, Keun-Jo;Lee, Cu-Ri
    • Journal of Korean Physical Therapy Science
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    • v.2 no.3
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    • pp.577-586
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    • 1995
  • This paper was the study of a change in the body temperature of each region(Oral cavity, Axillary, Cubital, Popliteal, Inguinal region)and by time after appling hot(Hot Pack, Infra Red) and cold (Ice Pack, Cooling Pack) to lumbar region. The statistical measures were sampled through 16 senior students in dept. of Physiothrapy, Kim Cheun College and the period for this was from July 13, 1995 to July 20, 1995. There was an increse in the temperature of distal portion besides application area after hot application. The increse in the body temperature according to applied agents and time showed significance statistically(p<0.01, p<0.05). There was just a decrease in the temperature of distal portions besides application area after appling Ice Pack. Furthermore there was an increase in the body temperature after appling Cooling Towel. Therefore, during cold application the appling agents and time did not showed any significance statistically.

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A Study on Germination Characteristics through Seed Variable Immersion for Restoration of North Korea Forest (북한산림복구용 종자 변온침지 처리를 통한 발아특성 연구)

  • Choi, Jong-O;Park, Yong-Jin
    • Journal of the Korean Society of Environmental Restoration Technology
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    • v.25 no.1
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    • pp.1-10
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    • 2022
  • This study was conducted to investigate the germination characteristics through the temperature change treatment compared to the general room temperature immersion treatment of the native species, the Larix kaempferi, and the Berula platyphyllavar. japonica seeds, and to obtain basic data for the production of healthy seedlings with high productivity and efficiency. As a result, the germination rate of the larch seeds showed a significant difference according to room temperature and temperature immersion treatment, and the average germination days of the birch seeds showed a significant difference according to room temperature immersion and temperature immersion treatment. On the other hand, there was no significant difference in germinal uniformity. The results of the study are as follows. First, the results of the analysis of the fallen leaves were the highest germination rate in the treatment of 1.5 days of hot water and 1.5 days of cold water, the fastest germination rate, the lowest average germination day, and the highest germination uniformity. This is the best result in most items, and the change temperature immersion treatment of hot and cold baths was superior to the conventional room temperature immersion treatment. Second, the results of birch tree showed that the germination rate was the highest in 1.5 days of hot water and 1.5 days of cold water. The average germination day is 1.5 days of cold water 1.5 days of hot water 1.5 days, but the difference between 1.5 days of hot water and 1.5 days of cold water is 0.01 days. The highest germinated uniformity was found in 1.5 days of cold water and 1.5 days of hot water. As a result, in the case of larch and birch, the seed temperature immersion (1.5 days of hot water, 1.5 days of cold water) treatment is superior to the existing three-day immersion treatment in various analysis methods, and it is expected that productivity and efficiency can be improved at a low cost in a short period of time at the seedling production site through seeds.

A Study on Technology Trend of Power Semiconductor Packaging using Topic model (토픽모델을 이용한 전력반도체 패키징 기술 동향 연구)

  • Park, Keunseo;Choi, Gyunghyun
    • Journal of the Microelectronics and Packaging Society
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    • v.27 no.2
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    • pp.53-58
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    • 2020
  • Analysis of electric semiconductor packaging technology for electric vehicles was performed. Topic modeling using LDA technique was performed by collecting valid patents by deriving valid patents. It was classified into 20 topics, and the definition of technology was defined through extracted words for each topic. In order to analyze the trend of each topic, the trend of power semiconductor packaging technology was analyzed by deriving hot and cold topics by topic through regression analysis on frequency by year. The package structure technology according to the withstand voltage, the input/output-related control technology and the heat dissipation technology were derived as the hot topic technology, and the inductance reduction technology was derived as the cold topic technology.