• Journal of the Korean Society of Food Science and Nutrition
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• v.42 no.8
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• pp.1270-1276
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• 2013

Laver, a red algae belonging to the genus Porphyra tenera, is one of the most widely consumed edible seaweeds in Korea, China, and Japan. Lavers are usually consumed in dried, roasted, and seasoned forms to improve their palatability. We evaluated the composition of amino acids, minerals, and trace heavy metals in these three differently cooked forms of laver. The moisture and ash contents of three differently cooked lavers ranged from 1.49~9.69% and 6.07~10.31%, respectively. The crude protein and lipid content ranged from 17.24~36.88% and 0.52~42.42%, respectively. Dried laver was found to be a good source of amino acids such as taurine, alanine, and glutamic acid (871.10 mg, 833.53 mg, and 719.77 mg per 100 g dry weight, respectively). Laver was a good source of macro and micro minerals such as K, Ca, Mg, Na, P, I, and Fe, although laver more extensively cooked (roasted and seasoned) contained less minerals compared to the dried form. Mercury levels in the three differently cooked forms of laver were all less than 100 ng/g dry weight (the limit of detection with our methodology). The levels of arsenic were the most abundant elements in the differently cooked laver. There was a clear variation, depending on the cooking process, in terms of amino acid, mineral, and trace metal contents of laver.

• Journal of Bio-Environment Control
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• v.22 no.2
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• pp.100-107
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• 2013

Unlike general microwave, QRD (Quadratic Residue Diffusor) Microwave used in this study is known as a new technology that enhances the sterilization effect with low power because it is possible to induce the average sterilization by changing wavelength phase difference. Therefore, basic research was conducted on the function that could sterilize culture media for plant factory by using environmentally friendly and low energy consuming QRD Microwave. The results are as follows: It was confirmed that there was no external deformation in the polyurethane foam and rock wool medium when changing the microwave level between 2 and 8 kW in different water content of culture media. However, PDA solid media at 2 kW were not dissolved in 60 and 180 seconds. All of the media were dissolved in other processing. There was little difference in the microwave irradiation level and surface temperature of the strain according to the processing time between Bacillus sp. and Burkholderia sp. In the sterility test according to the microwave irradiation level and processing time, it was confirmed that both Bacillus sp. and Burkholderia sp. grew in the microwave level 2 kW regardless of time. In the microwave level 6 kW, all experimental groups except the processing of Burkholderia sp. for 60 seconds were sterilized, and all of Bacillus sp. was killed in the all experimental groups. In the microwave level 8 kW, it was confirmed that both Bacillus sp. and Burkholderia sp. were sterilized regardless of time. The temperature in microwave-processed media after contaminating strains to each medium was maintained at more than 100 in polyurethane foam and rock wool medium after 60 seconds. In general, it was shown that it was possible to sterilize after 60 seconds. Therefore, it is considered that Bacillus sp. and Burkholderia sp. which are the biggest problems in the plant factory can be adequately sterilized by QRD Microwave used in this study.

• Food Science of Animal Resources
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• v.25 no.2
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• pp.134-140
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• 2005

This study was conducted to determine the effect of supplemented useful micro-organism on performance and meat quality of growing-finishing pigs for sixty days and broiler for six weeks. The pig and broiler were randomly allotted into 3 treatment; Control 0 (C), T1 (supplemented with $0.2\%$ Aspergillus terreus), T2 (supplemented with $0.2\%$ EM-pro). In total experimental period, feed conversion and dairy feed intake were tend to be higher in T2(2.09kg, 2.70kg) than others. But ADG (average daily gain) was tend to decreased n (0.78kg) according to supplemented of Aspergillus terreus diet These treatments were not significant difference. The chemical composition of pork were not significant difference except for crude fat Crude fat content was lower Aspergillus terreus treatments than others. The pH tenderness, WHC and heating loss were not significant difference in pork $(p>0.05)$. In chicken meat, heating loss and WHC of control was higher than that of T1 and n but shear value was higher in T1 and n. Values of juiciness, tenderness and flavor were improved with highly significant difference (p<0.05) in control (4.95, 4.85, 4.60) than T1 and n in pork. Although the meat color was not significant difference in pork but a and b values of control was higher than that of T1 and n in chicken meat (p<0.05).

• Applied Biological Chemistry
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• v.14 no.1
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• pp.9-18
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• 1971

In order to obtain basic information on the production of single cell protein from petroleum, more than 400 yeast strains were isolated from various soil samples in Korea utilizing petroleum hydrocarbon as the sole carbon source. A yeast strain showing the highest cell yield among the isolated strains was selected and identified. The optimal culture condition was searched in the flasks shaken throughout the procedure. And the growing characteristics for the selected yeast strain and chemical analysis of the yeast cell component were carried out. The results obtained were as follows: 1. The selected yeast strain was identified as Candida curvata and we named it Candida curvata-SNU 70. 2. The composition of the medium proposed for the present yeast strain is: Light Gas Oil 30ml, Urea 400mg, Ammonium sulfate 100mg, Potasium phosphate (monobasic) 670mg, Sodium phosphate (dibasic) 330mg, Magnesium sulfate 500mg, Calcium carbonate 3g, Yeast extract 50mg, Tween 20 0.05ml, Tap water 1,000ml. 3. Other culture conditions employed for the yeast were pH 5.5-7.0, temp. $30^{\circ}C$ under an affluent aerobic state. 4. Addition of light gas oil in portions to the culture media as the growth proceeded was more effective, especially in the cultivation on the higher oil concentration media. 5. Studies on the propagation of the yeast cells in the light gas oil medium revealed that the yeast has the lag phase lasted 16 hours and the logarithmic growth phase covered 16 to 28 hours. The specific growth rate was about $0.22\;hr^{-1}$ and doubling time was 3.2 hrs. during the logarithmic growth phase. 6. Under the cultural condition employed, the cell yield against the amount of light gas oil (wt%) was 16.1% and the protein content of the dried yeast cells was 48.4%.

• Korean Journal of Environmental Agriculture
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• v.27 no.4
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• pp.435-440
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• 2008

Bovine mastitis is an important disease causing serious economic loss in dairy production and food poison in public health. The major causative agents of bovine mastitis include Escherichia coli (E. coli), Streptococcus agalactiae (S. agalactiae), Staphylococcus aureus (S. aureus). These bacteria were found in milk and environmental condition such as feces, water, soil and so on. Recently, many cases of mastitis are derived from environmental contamination of micro-organisms, which important factors for the spread of this disease in farm. Ultraviolet irradiation (UV) has been used as disinfection for waste and water in clinical and industrial facilities. Moreover the UV irradiation has been used as useful bactericidal agents to remove bacterial biofilms in environmental condition. In this study, we determined the bacterial replication in different percentage of water content (PWC) in sterilized saw dust and feces complexes from farm, and results showed that slightly decreased growth pattern of E. coli and S. agalactiae but increased growth pattern of S. aureus in various PWC (200, 400 and 600%) until 144 h incubation. In the bacteriocidal effect of UV irradiation to bacteria in saw dust and feces complex, the results showed that bacteriocidal effect was depended on the UV irradiation time, irradiation distance and PWC. Especially the antibacterial activity of UV irratiation is stronger in low PWC (50%), long time irradiation (50 sec), and short distance (5 cm) than other condition of this study. Furthermore UV irradiation with stirring showed increased the bactericidal effect compared without stirring. These results suggested that bovine mastitis causing agents may survive long time in environmental condition especially saw dust and feces complexes in farm and can cause a various disease including mastitis. Moreover, these data can be used as basis for application and development of UV disinfection to control of bovine mastitis from environmental contaminated bacteria in dairy farm.

• Journal of Conservation Science
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• v.27 no.1
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• pp.101-114
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• 2011

The rock-carved Buddha statue at Dosolam (Korea Treasure No. 1200) of the Seonunsa temple in Gochang is unique style sculptured on natural rock cliff of 13.0m height. The Buddha statue is composed of volcanic complex with tuff, dacitic tuff breccia, tuff bereccia and lithic tuff. Especially, the Buddha statue is characterized by hydrothermal alteration and fragmentation on the upper and lower part. As a result of damage diagnosis, exfoliation and detachment of physical weathering are high of 11.3% and 9.3%, respectively. Infrared thermography analysis, exfoliation and micro-cracks occurred in the measuring parts that have not been confirmed by naked eyes. Chemical index of alteration and weathering potential index of host rock for the Buddha statue are 55.16 to 64.01 and 6.14 to 9.92 which are represented within highly weathering degree. In surface, dark black, reddish brown and white discoloration are observed prominently in the lower. Brown discoloration 6.9% is highest. According to the P-XRF measurements, high concentration of Fe in common, in part of dark black discoloration was Mn, white and brown discoloration in part of S and Ca content were higher. Biological weathering that yellowish brown and dark gray crustoes lichenes appeared by 20.8% and 13.3%, respectively. Therefore, comprehensive deterioration rate of Buddha statue show physical damage by 21.2%, discoloration for inorganic contaminants by 10.8% and biological damage by 39.4%. Ultrasonic velocity measurement carried out of Buddha statue on the surface by 555 points. Measured value of ultrasonic velocity was about 2,273m/s(1,067 to 3,215m/s, and weathering coefficient is 0.5(0.4 to 0.8) that progress on MW(moderately weathered) to HW(highly weathered) grade of rocks.

• Research in Plant Disease
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• v.14 no.1
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• pp.51-56
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• 2008

Powdery mildew of lettuce that is a newly reported disease became a threat to organic cultivation of lettuce in Korea since the disease caused by Podosphaera fusca resulted in a half of yield loss in heavily infected fields. To improve micro-environmental conditions around lettuce, ACF (air-circulation fan) was installed on inside roof of plastic house at 6 m intervals. The ACF increased 57% of lettuce yield and reduced 71.4% of lettuce seedling death. COY (cooking oil and yolk mixture) consisted of cooking oil 0.3% and egg yolk 0.08% reduced lettuce seedling death from 89.3% to 92.9% under the greenhouse. Seven-day interval spray of COY resulted in high control values of powdery mildew of lettuce ranging from 89.6% to 96.3%, which was comparable to a fungicide, Azoxystrobin. Lettuce yield was increased about two times compared to a non-treated conventional cultivation. Qualities of lettuce such as hardness and chlorophyll content were also improved by COY and ACF combination. Effect of COY on control of the disease was improved when $CaCO_3$ or $SiO_2$ 1,000 ppm was supplemented. Results indicated that the COY made of cooking oil such as canola emulsified with yolk was highly effective on control of powdery mildew of lettuce and suitable for organic agriculture, especially when combined with ACF.

• Food Science and Preservation
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• v.19 no.6
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• pp.799-806
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• 2012

This experiment was conducted to establish the optimum conditions for high $CO_2$ gas treatment in combination with a proper gas-permeable packaging film to maintain the quality of fig fruit (Ficus carica L). Among the fig fruits with different high $CO_2$ treatments, the quality change was most effectively controlled during storage in the 70%-$CO_2$-treated fig fruit. Harvested fig fruit was packaged using microperforated oriented polypropylene (MP) film to maintain the optimum gas concentrations in the headspace of packaging for the modified-atmosphere system. MP film had an oxygen transmission rate of about $10,295cm^3/m^2$/day/atm at $25^{\circ}C$. The weight loss, firmness, soluble-solid content (SSC), acidity (pH), skin color (Hunter L, a, b), and decay ratio of the fig fruits were monitored during storage at 5 and $25^{\circ}C$. The results of this study showed that the OPP film, OPP film + 70% $CO_2$, and MP film+70% $CO_2$ were highly effective in reducing the loss rate, firmness and decay occurrence rate of fig fruits that were packaged with them during storage. In the case of using treatments with packages of OPP film and OPP film+70% $CO_2$, however, adverse effects like package bursting or physiological injury of the fig may occur due to the gas pressure or long exposure to $CO_2$. Therefore, the results indicated that MP film containing 70% $CO_2$ can be used as an effective treatment to extend the freshness of fig fruits for storage at a proper low temperature.

• The Journal of Society for e-Business Studies
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• v.26 no.3
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• pp.55-66
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• 2021

The mobile application (APP) market is growing at an unprecedented speed. Amid such growth, the global platform providers are mandating exclusive in-app payments and charging 30% for platform commission fees. A serious tension has arisen between mobile global platform providers and local content providers. The present study attempts to analyze the domestic mobile game market and in-app payment commission fees. This study estimates the size of the domestic mobile game market and platform commission fees by directly using publicly available financial statements and footnote information of some representative listed mobile game firms. Also, the study analyzes the cost structures of the same sample firms and attempts to draw some implications on sustainable growths of the mobile game ecosystem. We estimated that, in 2019, the domestic mobile game market is around 4.9 trillion Won and the ensuing in-app payment commission fees market was 1.5 trillion Won. High market share firms display a proportional increase in in-app payment commission fees in relation to sales growth. This, in turn, makes the in-app payment commission fees a primary cost item far exceeding employee salaries and R&D expenses. During the same period, low market share firms generated a mere profit or experienced net loss. Analysis of the cost structure reveals that these firms are even more liable to higher in-app payment commission fee cost structure than high market share. Most constituents of the mobile game ecosystem are small business entrepreneurs. By employing a micro-level analysis, the study estimates that, in 2019, a representative median firm generates 530 million Won in sales. At the same time, it spends 190 million Won in employee salaries, 50 Won million in R&D and 190 million Won in in-app payment commission fees, respectively. In the absence of other cost items, these three cost items alone account for 73.8% of sales revenue. The results imply that a sustainable growth of the local mobile game market heavily depends upon the cost structure of such representative median firm, the in-app payment commission fees being the primary cost item of such firm.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.22 no.2
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• pp.139-147
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• 2021

Livestock manure is used as an organic fertilizer to replace chemical fertilizers after sufficient fermentation in an aerobic bioreactor. On the other hand, liquid manure disposal problems occur repeatedly because soil spraying is restricted during the summer when the crops are growing. To use liquid fertilizer (LF) as an additional nutrient source for crops, it is necessary to reduce the amount of suspended solids (SS) in the liquid fertilizer and secure stability problems against pathogenic microorganisms. This study examined the effects of the simultaneous SS removal and E.coli sterilization in the LF using the microbubble (MB) generator (FeMgO catalyst insertion). The remaining SS were further removed using the integrated microbubble and microfilter system. During the floating process in the MB device, the SS were removed by 57.9%, and the coliform group was not detected (16,200→0 MPN/100 mL). By optimizing the HRT of the integrated system, the removal efficiency of the SS was improved by 92.9% under the 0.1h of HRT condition. After checking the properties of the treated LF, 64.5%, 70.1%, 54.9%, and 51.5% of the TCOD, SCOD, PO4-P, and TN, respectively, were removed. The treated effluent from such an integrated system has a lower SS content than that of the existing LF and does not contain coliforms; therefore, it can be used directly as an additional fertilizer.