• Journal of the Korean Vacuum Society
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• v.16 no.3
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• pp.161-166
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• 2007

Photovoltaic (PV) technology permits the transformation of solar light directly into electricity. For the last five years, the photovoltaic sector has experienced one of the highest growth rates worldwide (over 30% in 2006) and for the next 20 years, the average production growth rate is estimated to be between 27% and 34% annually. Currently the cost of electricity produced using photovoltaic technology is above that for traditional energy sources, but this is expected to fall with technological progress and more efficient production processes. A large scale production of solar grade silicon material of high purity could supply the world demand at a reasonably lower cost. A shift from crystalline silicon to thin film is expected in the future. The technical limit for the conversion efficiency is about 30%. It is assumed that in 2030 thin films will have a major market share (90%) and the share of crystalline cells will have decreased to 10%. Our research at Sungkyunkwan University of South Korea is confined to crystalline silicon solar cell technology. We aim to develop a technology for low cost production of high efficiency silicon solar cell. We have successfully fabricated silicon solar cells of efficiency more than 16% starting with multicrystalline wafers and that of efficiency more than 17% on single crystalline wafers with screen printing metallization. The process of transformation from the first generation to second generation solar cell should be geared up with the entry of new approaches but still silicon seems to remain as the major material for solar cells for many years to come. Local barriers to the implementation of this technology may also keep continuing up to year 2010 and by that time the cost of the solar cell generated power is expected to be 60 cent per watt. Photovoltaic source could establish itself as a clean and sustainable energy alternate to the ever depleting and polluting non-renewable energy resource.

• Journal of Wetlands Research
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• v.15 no.4
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• pp.461-469
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• 2013

Even though a sewer rehabilitation BTL project has been executed throughout the nation with the input of a significant amount of budget, the overall review on effectiveness of the project is insufficient. And disputes over effectiveness of the project and of the employment of I/I indexes for evaluation of the project are continued due to reliable issues of flux data which has been measured after completion of certain projects and excessive amounts of I/I. Thus, this study has reviewed effectiveness of the project, current status and problems of the installation of fixed flow meters as well as countermeasures based on 15 projects subject to the operation performance evaluation after the completion of the project. The review on operation of the project has revealed that sewer rehabilitation BTL projects are significantly effective and highly effective on reducing a rate of infiltration water. The review on the employment of proper countermeasures for main issues revealed during the investigation on the installation and operation of fixed flow meters has shown that such countermeasures could result in securing more reliable flux data.

• Journal of the Korean Society of Marine Environment & Safety
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• v.16 no.4
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• pp.339-344
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• 2010

Oxygen depleted water mass can damage aquatic animals not only in direct way but also in indirect way by generating toxic substances including occurrence of hydrogen sulfide and ammonia which are also highly detrimental to animal life in the water mass. An oxygen dissolution device was developed, which makes turnover of the oxygen rich (over 20 mg/L) surface water down to the bottom where hypoxia is evident and tested the device in terms of oxygen recovery in the oxygen depleted bottom water. the device with turnover rates of $3.6\;m^2$/min at the liquid oxygen injection rate of 48~26.3 L/min could recover dissolved oxygen level to 7~25 mg/L at depth 7 m to lead to the dissolution level of over 90% by the supply of liquid oxygen. The running advantage of the device is that it does not require any auxiliary tank and higher energy for operation. Therefore, it can be highly useful device to relieve damages to the farmed animals in the oxygen depleted waters.

• Journal of fish pathology
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• v.6 no.2
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• pp.205-218
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• 1993

On the development of hirame(Paratichtys olivaceus) culture, outbreak of scuticociliata infection was reported to cause severe damage in Japan. To establish effective measures for isolation and cultivation of this ciliate, we tried to culture this pathogenic ciliate using medium for bacteria and fish cell lines in vitro. Scuticociliata from the brain tissues of infected fish was aseptically inoculated to CHSE-214 cells cultured in MEM-10 without antibiotic. Scuticociliata grew well and the number of ciliate reached $10^6\;cells/ml$ at temperatures of $15^{\circ}C$ to $20^{\circ}C$ for 10d. The number of ciliate cultured in the cell lines is 10 times higher than the numbers cultured in the liquid medium alone. This ciliata could be cloned by dilution method. Scuticociliata isolated could grow well on 42 different cell lines that were established from marine fish, warm freshwater fish, and salmonids. This ciliate could be preserved in liquid nitrogen for more than 6 months. Subsequently, we observed the optimal temperature and salinity for growth, and tested the sensitivities of this organism to formaldehyde, flagyl(Metronidazole), Ekuteshin(Combination compound of sulfamonometoxin and ormethoprim), and ozonixation. Optimal temperature for growth was $25^{\circ}C$ and salinity was 1.0 to 1.5%. Washed scuticociliata was killed by formaldehyde at the concentration of 50ppm for 10min, but was not completely killed even at a high concentration of 400ppm for 20min in MEM-5. Flagyl and Ekuteshin can inhibit the growth of scuticociliata at the concentration of 1,000 and $100{\mu}g/ml$ in MEM-10, respectively. More than 99% of this scuticociliata could be killed by ozonization at a dose equivalent to $1.0mg/\ell$ oxidant for 30sec in sea water. Isolated scuticociliata showed the pathogenicity to the cultured hirame by artificial infection(I. P. injection, $10^5\;cells$/fish). The number of scuticociliata in the water could be counted by most probable number(MPN) method using tissue culture, and the minimum detectable number was $1.8\;cells/\ell$. The number in the reservoir tank for water supply to the culture tank was 110 cells/l. After cleaning by elimination of the sediments from of the reservoir tank and disinfected with formaldehyde, number of scuticociliata decreased and was counted less than $1.8\;cells/\ell$ and infection rate of cultured hirame was decreased.

• Journal of Korea Port Economic Association
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• v.24 no.2
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• pp.289-315
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• 2008

In Korea-China shipping route, the level of freight rate has been maintained very low for last two decades not only because supply of shipping capacity is higher than its demand but also because the route was regulated by the two governments. An examination is made of the effects of openness of Korea-China Liner Shipping Route on competitiveness of Korean-flag Liner Shipping companies. This task is undertaken by detailing the development of the cargo sharing respectively by shipping companies of each country. Then it is suggested the ways to cope with the new environmental changes in Korea-China liner shipping route for the future by examining the future strategies for Korean-flag companies by in-depth interviews with major shipping companies.

• Journal of Ecology and Environment
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• v.35 no.4
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• pp.259-267
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• 2012

Biomass changes, net primary production and transfer dynamics of dry matter in four subtropical humid montane grasslands at Ebbenadu, Korakundah, Thiashola and Wenlockdown in Nilgiri Biosphere Reserve (NBR), the Western Ghats, India, were investigated. Despite the early report of a higher density and dominance of $C_4$ species over $C_3$ species in these grasslands, no functional study of matter production had previously been carried out. Therefore, in order to determine the roles played by these two groups of species, the present study was attempted. The study revealed that the dry matter and net primary production contributed by $C_4$ species were much greater than those of its $C_3$ counterpart in all the grasslands. The turnover rate of aboveground dry matter for both $C_3$ and $C_4$ species was generally rapid, whereas it was slow for belowground parts, and litter components of $C_3$ and $C_4$ species together. In all grasslands, generally about 60% and 10% of the input were channeled to aboveground and belowground parts, respectively, by the $C_4$ species, whereas the $C_3$ species transferred only about 22% and 8% of dry matter to aboveground and belowground parts, respectively. The total disappearance of dry matter was 2.73, 2.10, 3.19, and $1.96\;g\;m^{-2}\;day^{-1}$ in Ebbenadu, Korakundah, Thiashola and Wenlockdown grasslands, which was 48.83%, 44.30%, 54.81%, and 41.09% of the total input, respectively, in these grasslands. This resulted in a considerable surplus dry matter production in all the grasslands studied. This balance sheet of dry matter in community function indicates that all the four studied grasslands were supporting the existing wild animals adequately in terms of pasture supply. The study further revealed that the stronger establishment of $C_4$ species rather than their $C_3$ counterparts, in terms of higher density and dominance, has driven them to play major roles in matter dynamics and system transfer functions in all the four grasslands studied. This fact evidenced that pasture from $C_4$ species for wild animals was determined to be higher in comparison to that of $C_3$ species.

• Journal of Korea Multimedia Society
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• v.14 no.7
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• pp.895-904
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• 2011

In welding machine that executes existing spot welding, wrong operation of system has often occurs because of their mechanical motion that can be caused by a number of supply like the welding object. In exposed working environment for various situations such as worker or related equipment moving into any place that we are unable to exactly distinguish between good and not condition of nut. Also, in case of defective welding of nut, it needs various evaluation and analysis through image processing because the problem that worker should be inspected every single manually. Therefore in this paper, if the object was not stabilization state correctly, we have purpose to algorithm implementation that it is to reduce the analysis time and exact recognition as to improve system of image processing. As this like, as image analysis for assessment whether it is good or not condition of nut, in his paper, implemented algorithms were suggested and list by group and that it showed the effectiveness through more than one experiment. As the result, recognition rate of normality and error according to the estimation time have been shown as 40%~94.6% and 60%~5.4% from classification 1 of group 1 to classification 11 of group 5, and that estimation time of minimum, maximum, and average have been shown as 1.7sec.~0.08sec., 3.6sec.~1.2sec., and 2.5sec.~0.1sec.

• Journal of Nutrition and Health
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• v.17 no.3
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• pp.210-216
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• 1984

The growth response, lipid deposition, fat free body mass and energy expenditure of weanling rats fed the equal amount of isocaloric diets containing 8%, 13% and 18% casein were investigated. After a period of 30day feeding, the rats fed low level of protein diet were 43.01g lighter than 18% protein group (weight gains of ${85.57}{\pm}{7.50g}$ vs. ${128.58}{\pm}{11.64g}$, p<0.01). Despite of the smaller body size, there were no significant differences in lipid deposition in grams per carcass. Whereas, nitrogen accumulation was significantly greater in 13% and 18% protein fed groups compared to 8%. The estimated energy expenditure were 4,576.61 kJ, 5,440.80kJ and 5,607.67kJ for 8%, 13% and 18% protein groups respectively. The part of excess energy consumed by the low protein group may have been dissipated. The malic enzyme activity in the liver of rats was found to be unaltered by different dietary treatments. From these observations, it was conluded that the retarded growth response in lower protein level may have been originated from the shortage ge of protein supply rather than that of the energy. The protein restriction appeared to be resulted in the lower fat free compartment without affecting the ability of rats to synthesize body lipid in a similar rate to the higher protein group when energy intakes were equalized.

• Korean Journal of Poultry Science
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• v.22 no.3
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• pp.167-178
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• 1995

The purpose of this research was to get basic information for the development of Korean native chicken industry by reviewing the current native chicken farm management and marketing situation of native chicken products(meat and eggs). The research was carried on the basis of the farm field survey covering 210 native chicken feeders out of 9 different local areas, and the results were as follows ; 1. Average raising size of native chicken flocks of sample farms was 1,787 heads and about 50% of those farms raised less than 500 heads chickens for self-sufficiency or on the side. 2. Most farmers made the decision to start on feeding native chickens in small scale with small amount of capital without sound feeding program, and their decision was mainly influenced by recommendation of mass-media( 19.5%) and neighbors (17.2%). 3. The average income per farm earned by raising the native chickens was 13,719 Won, and income per head of chicken was 8,800 Won. 4. About 40% of feeders expressed that the poor marketing management and lack of capital were the bottleneck to native chicken farm management. 5. About 70% of feeders evaluated the prospect of native chicken industry positively and so, about 60% of feeders hoped to expand the raising size in the future. 6. Most farmers directry made a bargain with marketer including middleman and enduser in selling the chicken products because there was not established special marketing system for native chicken products. 7. The sales age of native broiler was about 16~20 weeks and average body weight of broiler was 1.5~2.0 kg. And farm recieved price was not decided on the basis of each body weight or meat quality but only number of heads. 8. The average first egg-laying age of chickens was about 165 days and average annual laying rate was only about 56%. 9. In order to develop the successful Korean native chicken industry, followings are recommended ; 1) Reducing the production costs and increasing the productivity of native chickens should be carried out through technological research and development for sound feeding program of native chickens and sufficient fund supply. 2) Orderly native chicken marketing and pricing system should be established to give good vision about native chickens to farmers and to delight the consumers. 3) The measures for product differentiation including meat quality and nutritional value of native chicken products against other improved chickens should be actively taken by feeders and government.

• KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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• v.18 no.1_2
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• pp.1-8
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• 2012

Kimchi, a Korean fermented vegetable is packaged without pasteurization and distributed with live bacteria actively working to produce lactic acid and carbon dioxide gas in the product. The $CO_2$ production consisting of two distinct phases of initial fast and later slow rates depends on kimchi type, salt content and storage temperature. The $CO_2$ produced from kimchi is accumulated in the product package causing volume expansion and pressure buildup. The dependence of $CO_2$ production rate on salt content and storage temperature has been published formerly and can be used for estimating the package volume and pressure under a variety of storage conditions. As methods to alleviate the problems from the produced $CO_2$, package designs with controlled diffusion pinhole, high $CO_2$ permeable film or $CO_2$ absorber have been tried by several researchers. Properly designed packages adopting the device or tool were shown to have high dissolved $CO_2$ in kimchi without volume expansion and pressure buildup, giving good sensory quality with carbonic taste. Advantages and limitations of each method have been discussed.