• Journal of the Microelectronics and Packaging Society
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• v.15 no.3
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• pp.47-52
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• 2008

This investigation was performed in order to study the properties of deposition and layers by Silicon Dioxide, SiO2, as dielectric onto Via and Trench which have high Aspect Ratio (AR). Thus, in order to confirm these properties, three types of CVD, which were PECVD, PETEOS, and ALD, were selected. On the experiment each of the property sections was estimated that step overage of PECVD: <30%, PETEOS: 45%, ALD: 75% and the RSM of PECVD: 27.8 nm, PETEOS: 2.1 nm, ALD: <2.0 nm. As a result of this experiment for the property of electric film, ALD was valuated to be the most favorable outcome. However, ALD was valuated to have the least quality for the deposition rate. ALD deposition rate, $10\;\AA/min$ by $1\;\AA$/1cycle, was prominently lower than PETEOS, which had the deposition rate of $5000\;\AA$/min. Since electric film requires at least $1000\;\AA$ thicknesses, ALD was not suitable for the deposition rate. which is the most important component in a practical use. Therefore, in this particular study, PETEOS was evaluated to be the most suitable recipe.

• Health Policy and Management
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• v.7 no.1
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• pp.100-124
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• 1997

In order to suggest the strategies for participation in the PPS(Prospective Payment System), analyses were performed based on variations in utilization pattern and changes in revenues of hospitals in 10 selected KDRGs. The data was collected from the claims data of a tertiary hospital in Kyunggido from September 1, 1995 to August 31, 1996. The studies consisted of 1, 718 inpatients diagnosed for lens procedures, tonsilectomy &/or adenoidectomy, appendectomy with complicated principal diagnosis, Cesarean section, or vaginal delivery without any complications. The resources used in each KDRG were measured including average length of stay, total charges, number of orders, intensity of medical services, frequencies of medical services, the rate of non-reimbursable charges, and the rate of non-reimbursable orders. Then, the changes in hopital revenues due to the composition of medical fee schedules under the PPS were estimated as follows: 1) The variations in average lenght of stay, total charges, number of orders, the intensity of medical services, the frequency of medical services, the rate of non-reimbursable charges, and the rate of non-reimbursable orders among the 10 KDRGs were comparatively small. 2) The average lenght of stay was the longest(6.0 days) for appendectomy with complicated principal diagnosis, while it was the shortest(2.1 days) for two vaginal deliveries. Statistically differences existed in the average length of stay among physicians and among the dates of admission in several KDRGs. 3) The total charges were the highest for lens procedures(1, 716, 000 won), while the lowest charges were for two vaginal deliveries(558, 000 won). Statistically differences in the total charges were found among physicians in several KDRGs: however, there were no differences with the dates of admission. 4) The number of orders was the greatest(155) for appendectomy with complicated principal diagnosis, while it was the smallest(75) for the two vaginal deliveries. Statistical differences in the number of orders did not exist among physicians in the KDRGs. 5) Significant differences were found in the intensity of medical services, and in the frequency of medical services among physicians in the KDRGs. 6) The rate of non-reimbursable charges for each KDRG was not related to the rate of non-reimbursable orders. The rate of non-reimbursable orders was the highest(36.0%) for lens procedures, while the lowest rate(11.6%) was for appendectomy with complicated principal diagnosis. The rate of non-reimbursable charges was the highest(39.4-39.7%) for vaginal deliveries, while the lowest rate(13.1%) was for tonsillectomy &/or adenoidectomy(<17 ages). 7) If the physician's practicing style were not change under the PPS, the hospital revenuses could be increased by 10%, and the portion of patient payment could be decreased by 1.4-22.4%. However, the non-reimbursable charges for showed little change between two reimbursement systems. Based upon the above findings, this hospital could be eligible for participation in the PPS(Prospective Payment Systm). However, the process of diagnosis and treatment should be standardized, inentifying methods to reduce cost and to assure quality of medical care. Furthermore, consideration should be given to finding ways to increase patient volume.

• Journal of the Korean Society of Food Culture
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• v.13 no.4
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• pp.275-291
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• 1998

Food irradiation is an emerging technology which offers many advantages such as reduction of microorganisms, extension of shelf-life of foods, reduction in the use of post-harvest chemicals, and destruction of insects and parasites. The commercial utilization of food irradiation, however, has been restricted because of the uncertainty of consumers' responses to it. Because success of food irradiation in the marketplace will depend upon their acceptability by consumers, this study focused on the consumers' perception and acceptance toward food irradiation in order to get basic data for commercial utilization of food irradiation and give information to consumers to help rational consumption behavior. The survey with 411 respondents living in Youngnam area was conducted during the spring of 1997 by the questionnaires. The results and implications from this study are as follows. First, consumers' knowledge about food irradiation is scanty. Two-thirds of respondents in the survey had not heard of irradiated foods and many people confused irradiation with radioactivity. In the willingness to accept food irradiation, one-third of respondents showed a wait-and-see attitude. This result indicated consumers had insufficient information about the irradiation process and nationwide education of food irradiation technology should be undertaken. Second, although the purchase and use of food are very important consumption behaviors, consumer education by mass communication has been rarely done. For the successful commercialization of food irradiation, the information provision by mass communication for the consumers should be made. Third, consumers generally worried about residual pesticide and intended to purchase irradiated foods if radioactivity was not retained in the foods. Therefore, food irradiation could be an alternative method to the use of pesticide Fourth, consumers pointed out that they wanted to extend shelf-life of milk and dairy foods, fish and seafood and to irradiate these foods. Therefore, research for the safety of irradiated foods should be continually conducted. finally, labeling for irradiated foods is needed to provide the information and to further increase public understanding. Especially, the labeling should show the definite reason why irradiation is being used. In conclusion, recently, under the circumstances that the commercial utilization of food irradiation and irradiation for the import and export products have been increased in many countries, many efforts are needed to improve the quality of irradiated foods, and prove the safety of them in Korea. In addition, consumer education for food irradiation should be given to help consumers to make decision for food purchase and use.

• Applied Biological Chemistry
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• v.32 no.4
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• pp.424-434
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• 1989

The rationale for the use of fungi in treating waste streams from food processing plants I~as been that of incorporating the dissolved and suspending nutrients into a macroscopic organism which can be filtered out readily. In order for a process using fungi to meet these objectives we examined a strain of fungi, Aspergillus fumigatus, which grew well on a variety of polysaccharide-containing materials and showed both efficient BOD removal and high quality protein recovery. In this experiment the fungal choice was based on the laboratory screening studies where the criteria used was BOD and COD reduction, growth response, mycelial yield, and the ability to compete with the natural flora. In the fermentation system used far the continuous culture of Aspergillus fumigatus the best combination of operating variables, inoculum ratio, temperature, initial pH, fermentation time and agitation rate was 5%(v/v), $35{\sim}40^{circ}C,\;pH\;4.5{\sim}5.0$, 2days and 150rpm, respectively. The fungus reduced BOD and COD to 94.0 and 90.4%, respectively and 3.15g of dry mycelium per liter of alcohol waste was harvested during 48hr of incubation time. The protein efficiency ratios for the control diet and the experimental diet containing the fungal protein were $3.42{\pm}0.15$ and $3.40{\pm}0.43$, respectively.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.24 no.5
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• pp.196-201
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• 2014

We investigated defects and surface polarity in AlN and GaN by using wet chemical etching. Therefore, the effectiveness and reliability of estimating the single crystals by defect selective etching in NaOH/KOH eutectic alloy have been successfully demonstrated. High-quality AlN and GaN single crystals were etched in molten NaOH/KOH eutectic alloy. The etching characteristics and surface morphologies were carried out by scanning electron microscope (SEM) and atomic force microscope (AFM). The etch rates of AlN and GaN surface were calculated by etching depth as a function of etching time. As a result, two-types of etch pits with different sizes were revealed on AlN and GaN surface, respectively. Etching produced hexagonal pits on the metal-face (Al, Ga) (0001) plane, while hexagonal hillocks formed on the N-face. On etching rate calibration, it was found that N-face had approximately 109 and 15 times higher etch rate than the metal-face of AlN and GaN, respectively. The size of etch pits increased with an increase of the etching time and they tend to merge together with a neighbouring etch pits. Also, the chemical mechanism of each etching process was discussed. It was found that hydroxide ion ($OH^-$) and the dangling bond of nitrogen play an important role in the selective etching of the metal-face and N-face.

• Journal of the Korean GEO-environmental Society
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• v.18 no.4
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• pp.23-29
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• 2017

As the Enforcement Ordinance of Environmental Policy Act was revised in 2013, Total Organic Carbon (TOC) was added as an indicative parameter for organic matter in Water and Aquatic Ecosystem Environmental Criteria. Under these imminent circumstances, a regulatory standard is needed to achieve the proposed TOC limitation control water quality from the STP (Sewage Treatment Plant). In this study, a electrolysis utilizing the electrochemical reaction was investigated in lab-scale experiments for the treatment of TOC in sewage effluent. TOC reduction by a electrolysis was investigated response surface methodology using the Box-Begnken methods were applied to the experimental results. A central composite design was used to investigate the effects of the independent variables of electrode space ($x_1$), current density ($x_2$) and electrolyte concentration ($x_3$) on the dependent variables removal efficiency of TOC (y). The optimal conditions for electrolysis were determined: electrode space, current density and electrolyte concentration were 50 mm, $10.3mA/cm^2$ and 0.1M, respectively. Statistical results showed the order of significance of the independent variables to be electrode space > current density > electrolyte concentration.

• Journal of the Korean Geosynthetics Society
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• v.14 no.2
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• pp.95-103
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• 2015

In this study, the causes and countermeasures for the leakage of a sea dyke under construction are analyzed. In general, the seabed ground is clearly divided from the embankment but a lot of parts show abnormal zones with low resistivity from the results of electric resistivity survey. Hence the causes of the leakage are considered as following: three-dimensional shear strain behavior, irregular compulsory replacement of the soft seabed ground with low strength and quality deterioration of the waterproof sheets during the closing process. The improvement method is determined by considering the constructability in the seawater and its velocity condition, durability, economic feasibility, similar application cases and so on. Consequently, a combination of low slump mortar and slurry grouting and injection method is selected as an optimum combination. Mixing ratio and improvement pattern are determined after drilling investigation and pilot test. The improvement boundary is separated into general and intense leakage area. The construction is performed with each pattern and the improvement effects are confirmed. The confirmed effects with various tests after completion show tolerable ranges for all of the established standards. Finally, various issues such as prediction of length of the waterproof sheet, installation of it against seawater velocity, etc. should be considered when sea dykes are designed or executed around the western sea which has high tide difference.

• Journal of the Korean earth science society
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• v.38 no.7
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• pp.496-510
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• 2017

This study presents a new nationwide quantitative precipitation estimation (QPE) based on the hybrid surface rainfall (HSR) technique using the weather radar network of Korea Meteorological Administration (KMA). This new nationwide HSR is characterized by the synthesis of reflectivity at the hybrid surface that is not affected by ground clutter, beam blockage, non-meteorological echoes, and bright band. The nationwide HSR is classified into static (STATIC) and dynamic HSR (DYNAMIC) mosaic depending on employing a quality control process, which is based on the fuzzy logic approach for single-polarization radar and the spatial texture technique for dual-polarization radar. The STATIC and DYNAMIC were evaluated by comparing with official and operational radar rainfall mosaic (MOSAIC) of KMA for 10 rainfall events from May to October 2014. The correlation coefficients within the block region of STATIC, DYNAMIC and MOSAIC are 0.52, 0.78, and 0.69, respectively, and their mean relative errors are 34.08, 30.08, and 40.71%.

• Journal of the Korean Society of Food Science and Nutrition
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• v.33 no.2
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• pp.433-438
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• 2004

This study was conducted to develop a sweet pumpkin to intermediate materials for various processed foods and dried food having high quality. Factorial experiment design with three variables having three levels was adapted and response surface methodology was used to determine optimum conditions for osmotic dehydration of sweet pumpkin. The moisture content, weight reduction, moisture loss and solid gain after osmotic dehydration increased according to increasement of immersion temperature, concentration and time. The effect of concentration was more significant than that of temperature and time at given conditions. Sugar concentration and vitamin C content increased in accordance with increasement of immersion temperature, concentration and time during osmotic dehydration. Hardness was increased by increasing immersion time. The regression models showed very significant values and high correlation coefficients (R2) above 0.91, excepting hardness. The optimum condition for osmotic dehydration was 23$^{\circ}C$, 52$^{\circ}C$Brix and 80 min at the constricted conditions such as 60∼70% moisture content, above 3 mg/100 g vitamin C and more than 10 kg/$\textrm{cm}^2$ hardness.

• Journal of the Korean Society of Food Science and Nutrition
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• v.31 no.1
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• pp.75-80
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• 2002

The growth inhibition by nisin-Producing lactococci against Bacillus subtilis and its application to doenjang fermentation were investigated. Lactococcus lactis subsp. lactis IFO 12007, L. lactis subsp. lactis ATCC 7962 and L. lactis subsp. lactis ATCC 11454 were used as nisin-producing lactococci. All of three strain rapidly proliferated to more than 10$^{9}$ CFU/g in steamed soybeans. Only L. lactis subsp. lactis IFO 12007 was in steamed soybean without any pH decrease. In spite of the mild decrease in pH, the growth of B. subtilis was completely inhibited; no living cells were detected in a soybean sample inoculated with 10$^{6}$ CFU/g and incubated for 24 to 72h. The L. lactis subsp. lactis IFO 12007 was applied to doenjang fermentation as a starter culture. It produced high nisin activity in steamed soybean, resulting in the complete growth inhibition of B. subtilis, which had been inoculated at the beginning of the meju fermentation, throughout the process of doenjang production. Over-acidification, which is undesirable for doenjang quality, was successfully prevented simply by adding salt which killed the salt-intolerant L. lactis subsp. lactis IFO 12007. Furthermore, the nisin activity in doenjang disappeared with aging.