• 한국수소및신에너지학회논문집
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• 제18권2호
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• pp.157-163
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• 2007

During PEMFC operation, low current and low humidity conditions accelerate the degradation of perfluorosulfonic acid membrane. But, there have been no studies that clearly explain why these conditions accelerate the membrane degradation. In this study, the hydrogen permeability through the membrane, I-V polarization of MEA, fluoride emission rate(FER) in effluent water were measured during cell operation under low current densities and low relative humidity(RH). The experimental results were evaluated with oxygen radical mechanism the most commonly known for membrane degradation. It seems that low RH of anode is a good condition for $H{\cdot}$ radical formation on the Pt catalyst and the low current condition accelerates the $H{\cdot}$ to form $HO_2{\cdot}$ radical attacking the polymer membrane.

• 한국재료학회지
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• 제13권5호
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• pp.338-342
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• 2003

Adhesion between Cu and low-k films has been investigated. Low-k films deposited using a mixture of hexamethyldisilane(HMDS) and Para-xylene had a dielectric constant as low as 2.7, showing the thermally stable properties up to $400^{\circ}C$. In this study, Ti glue layer, boron dopant, and $N_2$plasma treatment were used to improve adhesion property of between Cu and low-k films. Ti glue layer slightly improved adhesion property. After $N_2$plasma treatment, the adhesion property was significantly improved due to the increased roughness and the formation of new binding states between Ti and plasma-treated PPpX : HMDS. However, $300^{\circ}C$ annealing of $N_2$plasma treated sample caused the diffusion of Cu into the PPpX : HMDS, degrading the low-k properties. In the case of Cu(B)/Ti/PPpX : HMDS, the adhesion was remarkably increased. This enhanced adhesion was attributed to formation of Ti-boride at the Cu-Ti interface. It is because the formed Ti-boride prevented the diffusion of Cu into the PPpX : HMDS and the Cu-Ti reaction at the Ti interface.

• Journal of Acupuncture Research
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• 제27권1호
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• pp.31-41
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• 2010

Objectives : The purpose of this study is to set up the standard for Classification and Diagnosis of Low Back Pain by through collecting bibliographic study on Low Back Pain and related general symptoms in classical literatures Methods : We investigated the contents of classical literatures about chronic low back pain and related general symptoms. With this contents, we established a systemic classification and diagnostic standard for Low back pain. Results : There are many different opinions on classification of low back pain and general symptoms in oriental medicine classical literature. Every opinion is reasonable, so it is difficult to establish a diagnosis of Low back pain. But it is necessary to set up the one-systemic classification and diagnostic technique of Low back pain. Conclusions : We conclude that the Ten type Low back pain classification of in Dong-Eui-Bo-Gam is a reasonable standard for diagnostic classification.

• Journal of Dairy Science and Biotechnology
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• 제35권1호
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• pp.47-54
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• 2017

There has been an increasing interest in low-fat foods among consumers worldwide. However, very few dairy companies produce low-fat cheese in Korea. Therefore, low-fat cheese production must be studied to not only promote consumer health but also diversify the domestic natural cheese market. In this study, we attempted to soften the texture of low-fat Mozzarella cheese prepared from raw milk standardized to 2% by changing the temperature of the cooking process from $43^{\circ}C$ to $37^{\circ}C$ and $40^{\circ}C$. The protein and fat contents of low-fat Mozzarella cheese prepared at the selected temperatures was 5.10-7.01% higher and 5.24-6.38% lower, respectively, than that of control cheese. Moreover, the hardness of low-fat Mozzarella cheese decreased with increasing cooking temperature. Further research to improve the sensory characteristics of low-fat cheese is required.

• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 2004년도 Proceedings of ISRS 2004
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• pp.184-187
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• 2004

Three HF ocean radar stations were installed at the Soya Strait in the Sea of Okhotsk in order to monitor the Soya Warm Current. Frequency of the HF radar is 13.9 MHz, and range and azimuth resolutions are 3 km and 5 deg., respectively. Surface current velocity observed by the radars shows good agreement with drifting buoy and shipboard ADCP observations. The velocity of Soya Warm Current reaches its maximum, which is about 1 m/s, in summer, and becomes weak in winter. The surface transport across the strait shows a significant correlation with the sea level difference along the strait.

• 한국축산식품학회지
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• 제37권5호
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• pp.698-707
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• 2017

This study was performed to investigate the impacts of irradiation sources on quality attributes of low-salt sausage during refrigerated storage. Control sausage was prepared with 1.5% sodium chloride (NaCl), whereas low-salt sausage was formulated with 0.75% NaCl (a 50% reduction; L-control). Sausage samples were vacuum-packaged, and low-sausages were irradiated with gamma-ray, electron-beam and X-ray at 5 kGy, respectively. The samples were stored at $4^{\circ}C$ for 28 d to determine changes in quality attributes. The pH of low-salt sausages was unaffected by irradiation at 5 kGy (p>0.05). Higher redness values were found at irradiated low-salt sausages compared to control (p<0.05). The hardness, gumminess and chewiness of control sausage were higher than those of low-salt sausages (p<0.05). However, there were no significant differences in the textural parameters between low-salt sausage treatments. The overall sensory acceptability score of irradiated/low-salt sausages were lower than L-control due to decreased scores for cooked meat flavor but increased radiolytic off-flavor (p<0.05). The initial 2-thiobarbituric acid-reactive substances (TBARS) values of irradiated/low-salt sausages were higher than control and L-control (p<0.05). However, the TBARS values of irradiated treatments were significantly lower than control at the end of storage. Irradiation could effectively inhibit the microorganism growth (total aerobic bacteria, coliforms, Enterobacteriaceae, and Pseudomonas spp.) in low-salt sausages (p<0.05). Therefore, our findings show that irradiation could be to improve microbial safety of low-salt sausages, and suggest that further studies should be necessary to reducing radiolytic off-flavor of irradiated/low-salt sausages.

• 한국레이저가공학회:학술대회논문집
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• 한국레이저가공학회 2006년도 추계학술발표대회 논문집
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• pp.128-132
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• 2006

Low-k wafer engraving process has been investigated by using UV pico-second laser with high repetition rate. Wavelength and repetition rate of laser used in this study are 355nm and 80MHz, respectively. Main parameters of low-k wafer engraving processes are laser power, work speed, assist gas flow rate, and protective coating to eliminate debris. Results show that engraving qualities of low-k layer by using UV pico-second pulse width and high repetition rate had better kerf edge and higher work speed, compared to one by conventional laser with nano-second pulse width and low repetition rate in the range of kHz. Assist gas and protective coating to eliminate debris gave effects on the quality of engraving edge. Total engraving width and depth are obtained less than $20{\mu}m$ and $10{\mu}m$ at more than 500mm/sec work speed, respectively. We believe that engraving method by using UV pico-second laser with high repetition rate is useful one to give high work speed of laser material process.

• 반도체디스플레이기술학회지
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• 제6권1호
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• pp.11-15
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• 2007

Low-k wafer engraving process has been investigated by using UV pico-second laser with high repetition rate. Wavelength and repetition rate of laser used in this study are 355 nm and 80 MHz, respectively. Main parameters of low-k wafer engraving processes are laser power, work speed, assist gas flow, and protective coating to eliminate debris. Results show that engraving qualities of low-k layer by using a laser with UV pico-second pulse width and high repetition rate had better kerf edge and higher work speed, compared to one by conventional laser with nano-second pulse width and low repletion rate in the range of kHz. Assist gas and protective coating to eliminate debris gave effects on the quality of engraving edge. Total engraving width and depth are obtained less than $20\;{\mu}m$ and $10\;{\mu}m$ at more than 500 mm/sec work speed, respectively. We believe that engraving method by using UV pico-second laser with high repetition rate is useful one to give high work speed in laser material process.

• Journal of the Korean Institute of Landscape Architecture International Edition
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• 제1호
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• pp.213-218
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• 2001

To many developing countries like China, the practical way to constant development of city construction is low consuming. The basic methods of low-cunsuming landscape construction: 1) Low building consumption: Decreasing construction quantity. Using low-costing material. Designing low-consuming landscape. Reusing of building material. 2) Low energy consumption: Decreasing water consumption. Consuming and enrichment of earth fertilizer. Decreasing electrical consumption. 3) Low maintenance: Adapting natural material. Using local plants. Special design to decrease maintaining. Because of many reasons, China has not yet adapting Low-consuming Landscape Construction.

• 대한영양사협회학술지
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• 제19권3호
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• pp.223-235
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• 2013

The purpose of this study was to identify the association between health-related behaviors including smoking, alcohol intake, and the practice of a low-salt diet using data from a Community Health Survey conducted in 2008. The study subjects were 129,151 persons (19 years and older) without cardiovascular diseases or diabetes mellitus diagnosis history. An index for evaluating low salinity was created by summing three low salinity-related questions (range: 0~3), and a low-salt diet was defined if the index of low salinity was 3. We examined the levels of smoking and alcohol intake according to the index of low salinity, and conducted multiple logistic regression analysis to examine the odds ratios of low-salt diet practice in relation to smoking and drinking behavior, adjusting for general characteristics. The smoking and drinking status significantly improved as the level of low salinity index increase. Adjusting for general characteristics, those with smoking, alcohol intake, or a combined habit of the two behaviors had significantly lower odds ratios for practice of a low-salt diet. In conclusion, smoking and drinking behavior were negatively associated with the practice of a low-salt diet. Based on these findings, it may be necessary to have comprehensive nutritional education programs that consider the multiple effects of smoking, drinking, and a low-salt diet.