• KOREAN JOURNAL OF CROP SCIENCE
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• v.54 no.4
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• pp.458-463
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• 2009

In this study, white ginseng water extract (WGWE) solutions were analyzed to set up the functional saponin content and quality optimization condition. The highest saponin content among the total white ginseng extracts was 8.32 mg/10 ml which was extracted at $75^{\circ}C$ for 18 hours. In addition, the saponin content decreased according to the increased extraction temperature and time. The highest content of $Rb_2$ and Re was 0.89 mg/10 ml, 0.82 mg/10 ml at $75^{\circ}C$ for 18 hours which decreased according to the increased extracted temperature and time. The highest content of $Rg_3$ was 1.67 mg/10 ml at $95^{\circ}C$ for 24 hours which decreased according to the increased time. The turbidity, sweetness and reducing sugar content were increased according to the increased extracted time at $75^{\circ}C$, $85^{\circ}C$, $95^{\circ}C$, but pH were decreased according to the increased extracted time. Therefore, the most appropriate white ginseng extracting method have to extracted the proper temperature for saponin content at first time in combination with raise the temperature for taste at second time.

• Korean Journal of Microbiology
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• v.47 no.2
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• pp.117-123
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• 2011

The purpose of this study was to evaluate and compare different elution and concentration methods for optimization of human rotavirus (HRV) detection method using real-time RT-PCR and cell culture techniques. The leafy vegetable samples (lettuce, Chinese cabbage) were artificially inoculated with HRV. Viruses were extracted from the vegetables by two different elution buffers, buffer A (100 mM Tris-HCl, 50 mM glycine, 3% beef extract, pH 9.5) and buffer B (250 mM Threonine, 300 mM NaCl, pH 9.5), and the extracted viruses were concentrated by filtration and PEG precipitation sequentially. To determine infectivity of the viruses, the viruses recovered from the samples were infected to the MA-104 cells, and integrated cell culture real-time RT-PCR was performed at 1, 48, 72, 96, 120, 144, 168 h post-infection (p.i.). The elution buffer A was more efficient in extracting the virus from the produce samples tested than the buffer B, 29.54% and 18.32% of recoveries, respectively. The sensitivity of real-time RT-PCR method was markedly improved when the virus was concentrated by the filtration method. When the viruses were eluted and concentrated by buffer A and filtration, respectively, the average recovery rate was approximately 51.89%. When the viruses recovered from samples were infected to MA-104 cell, infectious HRV was detected within 48 h p.i. by ICC/real-time RT-PCR, whereas cytopathic effects were not observed until 72 h p.i. The optimized detection method evaluated in this study could be useful for rapid and reliable detection of HRV in fresh produce products and applied for detection of other food-borne viruses.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.2
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• pp.56-63
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• 2018

The management of Combined Sewer Overflows(CSOs) and Separated Sewer Overflows(SSOs) discharge directly to the effluent system in an untreated state, which occurs when the facility capacity is exceeded due to heavy rain, has become an important issue in recent years as the heavy rain becomes a regular phenomenon. Despite the continuous development of filtration technology, targeting densely populated urban areas, CSOs are rarely applied. Therefore, this study was carried out to optimize the process to apply CSOs in a pilot-scale horizontal flow filtration system with a rope-type synthetic fiber. The research was carried out in two steps: a preliminary study using artificial samples and a field study using sewage. In the preliminary study using an artificial sample, head loss of the filter media itself was analyzed to be approximately 1.1cm, and the head loss was increased by approximately 0.1cm as the linear velocity was increased by 10m/hr. In addition, the SS removal efficiency was stable at 81.4%, the filtration duration was maintained for more than 6 hours, and the average recovery rate of 98% was obtained by air backwashing only. In the on-site evaluation using sewage, the filtration duration was approximately 2 hours and the average removal efficiency of 83.9% was obtained when belt screen (over 450 mesh) was applied as a pre-treatment process to prevent the premature clogging of filter media. To apply the filtration process to CSOs and SSOs, it was concluded that the combination with the pre-treatment process was important to reinforce the hydraulic dimension for the stable maintain of operation period, rather than efficiency. Compared to the dry season, the quality of incoming sewage was lower in the rainy season, which was attributed to the characteristics of the drainage area with higher sanitary sewerage. In addition, the difference in removal efficiency according to the influent quality of the wet season and dry season was small.

• Journal of Plant Biotechnology
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• v.38 no.4
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• pp.293-300
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• 2011

This study is conducted to develop an efficient transformation system via particle bombardment with PLBs (Protocorm-like bodies) in Cymbidium. For this, pCAMBIA3301 vector which carries a herbicide-resistant bar gene and gus gene as a reporter gene was used for transformation with Cymbidium cultivars 'Youngflower ${\times}$ masako' line. To select transformants, proper concentration of herbicide, PPT (phosphinotricin), should be determined. As a result, 5 mg/l of PPT was selected as a proper concentration. Further, proper conditions for particle bombardment were determined to obtain a high frequency of transformation. Results showed that 1.0 ${\mu}g$ of DNA concentration, 1,100 and 1,350 psi for helium gas pressure, 1.0 ${\mu}m$ of gold particle and 6 cm of target distance showed the best result for the particle bombardment experiment. Also, pre-treatment with combination 0.2 M sorbitol and 0.2 M mannitol for 4 hrs prior to genetic transformation increased the transformation efficiency up to 2.5 times. Using transformation system developed in this study, 3.2 ~ 4.0 transgenic cymbidium plants can be produced from 100 bombarded PLBs on average. Putative transgenic plants produced in this system confirmed the presence of the bar gene by PCR analysis. Also, leaves from randomely selected five transgenic lines were applied for Basta solution (0.5% v/v) to check the resistance to the PPT herbicide. As a result, three of them showed resistance and one of them showed the strongest resistance with the maintenance of green color as non-transformed plants showed. Using this established transformation system, more genes of interests can be introduced into Cymbidium plants by genetic transformation in the future.

• Radiation Oncology Journal
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• v.20 no.4
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• pp.295-302
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• 2002

Purpose : The Purpose of this study was to establish general guidelines for the treatment of patients with early glottic carcinoma (T1-2N0M0), by assessing the role of primary radiotherapy and by analyzing the tumor-related and treatment-related factors that have an influence on the treatment results. Materials and Methods : This retrospective study was composed of 80 patients who suffered from early glottic carcinoma and were treated by primary radiotherapy at Pusan National University Hospital, between August 1987 and December 1996. The distribution of patients according to T-stage was 66 for stage T1 and 14 for stage T2. All of the patients were treated with conventional radical radiotherapy using a 6MV photon beams, a total tumor dose of $60\~75.6\;Gy$ (median 68.4 Gy), administered in 5 weekly fractions of $1.8\~2.0\;Gy$. The overall radiation treatment time was from 40 to 87 days, median 51 days. All patients were followed up for at least 3 years. Univariate and multivariate analysis was done to identify the prognostic factors affecting the treatment results. Results : The five-years survival rate was $89.2\%$ for all patients, $90.2\%$ for T1 and $82.5\%$ for T2. The local control rate was $81.3\%$ for all patients, $83.3\%$ for T1 and $71.4\%$ for T2. However, when salvage operations were taken into account, the ultimate local control rate was $91.3\%,\;T1\;94.5\%,\;T2\;79.4\%$, reprosenting an increase of $8\~12\%$ in the local control rate. The voice preservation rate was $89.2\%,\;T1\;94.7\%,\;T2\;81.3\%$. Fifteen patients suffered a relapse after radiotherapy, among whom 12 patients underwent salvage surgery. We included T-stage, tumor location, total radiation dose, fraction size, field size and overall radiation treatment time as potential prognostic factors. T-stage and overall treatment time were found to be statistically significant in the univariate analysis, but in the multivariate analysis, only the over-all treatment time was found to be significant. Conclusion : The high cure and voice preservation rates obtained when using a procedure, comprising a combination of radical radiotherapy and salvage surgery, may make this the treatment of choice for patients with early glottic carcinoma. However, the prognostic factors affecting the treatment results must be kept in mind, and more accurate treatment planning and further optimization of the radiation dose are necessary.

• Land and Housing Review
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• v.2 no.4
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• pp.453-461
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• 2011

This study is to derive a project model based on potential demand for Korean-style houses, focusing on new town detached housing sites that LH supplies and to test validity of the derived model and to present the direction and supply methods of the projects. The existing high-class new town Korean-style housing developments that have been considered were found to have little business value due to problems in choice of location and discordance of demand, so 6 types of projects were established through the methods of changes in planned scale, combined use, and subdivision of plot of land based on the results of survey. The type that has the highest business value among the project models was block-type multifamily houses, and this can be interpreted as the increase in total construction area leading to increase inrevenues of allotment sales due to economies of scale. The feasibility of mass housing model in which small-scale Korean-style houses are combined with amenities was found to be high, and if the same project conditions as those of the block-type multifamily houses are applied, the business value of the Korean-style tenement houses was found to be high. Besides, the high-class housing models within block-type detached housing areas are typical projects that the private sector generally promotes, and the construction cost was found to be most expensive with 910 million won per house. In order to enhance the business value of the Korean-style housing development, collectivization such as choice of location, diversification of demand classes, optimization of house sizes, and combination of uses is needed. And in order to adopt Korean-style houses in the detached housing sites, the adjustments and division of the existing planned plots are needed, and the strategies to cope with new demand through supplying Korean-style housing types of sites can be suggested. Also breaking away from the existing uniform residential development methods, the development method through supplying original land that is natural land not yet developed besides basic infrastructures (main roads and water and sewage) can be considered, and as the construction of more than 1~2 stories building is impossible due to the structure of Korean-style house roof and furniture. So it can be suggested that original land in the form of hilly land is considered to be most suitable to large-scale development projects.

• Journal of Energy Engineering
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• v.28 no.3
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• pp.65-79
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• 2019

The study attempted to estimate the optimal facility capacity by combining renewable energy sources that can be connected with gas CHP in industrial complexes. In particular, we reviewed industrial complexes subject to energy use plan from 2013 to 2016. Although the regional designation was excluded, Sejong industrial complex, which has a fuel usage of 38 thousand TOE annually and a high heat density of $92.6Gcal/km^2{\cdot}h$, was selected for research. And we analyzed the optimal operation model of CHP Hybrid System linking fuel cell and photovoltaic power generation using HOMER Pro, a renewable energy hybrid system economic analysis program. In addition, in order to improve the reliability of the research by analyzing not only the heat demand but also the heat demand patterns for the dominant sectors in the thermal energy, the main supply energy source of CHP, the economic benefits were added to compare the relative benefits. As a result, the total indirect heat demand of Sejong industrial complex under construction was 378,282 Gcal per year, of which paper industry accounted for 77.7%, which is 293,754 Gcal per year. For the entire industrial complex indirect heat demand, a single CHP has an optimal capacity of 30,000 kW. In this case, CHP shares 275,707 Gcal and 72.8% of heat production, while peak load boiler PLB shares 103,240 Gcal and 27.2%. In the CHP, fuel cell, and photovoltaic combinations, the optimum capacity is 30,000 kW, 5,000 kW, and 1,980 kW, respectively. At this time, CHP shared 275,940 Gcal, 72.8%, fuel cell 12,390 Gcal, 3.3%, and PLB 90,620 Gcal, 23.9%. The CHP capacity was not reduced because an uneconomical alternative was found that required excessive operation of the PLB for insufficient heat production resulting from the CHP capacity reduction. On the other hand, in terms of indirect heat demand for the paper industry, which is the dominant industry, the optimal capacity of CHP, fuel cell, and photovoltaic combination is 25,000 kW, 5,000 kW, and 2,000 kW. The heat production was analyzed to be CHP 225,053 Gcal, 76.5%, fuel cell 11,215 Gcal, 3.8%, PLB 58,012 Gcal, 19.7%. However, the economic analysis results of the current electricity market and gas market confirm that the return on investment is impossible. However, we confirmed that the CHP Hybrid System, which combines CHP, fuel cell, and solar power, can improve management conditions of about KRW 9.3 billion annually for a single CHP system.

• Journal of Korean Tunnelling and Underground Space Association
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• v.21 no.1
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• pp.61-77
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• 2019

If a new utility tunnel is planned for high density existing urban areas in Korea, a rational decision-making process such as the determination of optimum design capacity by using the feasibility evaluation system based on quantitative evaluation indexes and the economic evaluation is needed. Thus, the previous study presented the important weight of individual higher-level indexes (3 items) and sub-indexes (16 items) through a hierarchy analysis (AHP) for quantitative evaluation index items, considering the characteristics of each urban type. In addition, an economic evaluation method was proposed considering 10 benefit items and 8 cost items by adding 3 new items, including the effects of traffic accidents, noise reduction and socio-economic losses, to the existing items for the benefit cost analysis suitable for urban utility tunnels. This study presented a quantitative feasibility evaluation method using the important weight of 16 sub-index items such as the road management sector, public facilities sector and urban environment sector. Afterwards, the results of quantitative feasibility and economic evaluation were compared and analyzed in 123 main road sections of the Seoul. In addition, a comprehensive evaluation method was proposed by the combination of the two evaluation results. The design capacity optimization program, which will be developed by programming the logic of the quantitative feasibility and economic evaluation system presented in this study, will be utilized in the planning and design phases of urban community zones and will ultimately contribute to the vitalization of urban utility tunnels.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.34 no.1
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• pp.60-73
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• 1989

Two field experiments were carried out to assess the applicability of a central composite design (CCD) in determining optimum culture condition of an early rice cultivar, Unbongbyeo in southern Korea. A central composite design with two replicates was applied to five levels of five factors such as the number of hills per 3.3m2, the number of seedlings per hill, the levels of nitrogen, the transplanting date and the seedling age (Experiment 1). The levels of planting density were ranged from 30 hills to 150 hills per 3.3m2 ; the number of seedlings per hill from 1 seedling to 9 seedlings per hill; the levels of nitrogen application from 1 kg/l0a to 21 kg/l0a; the transplanting date from June 15 to July 5; the seedling age from 25 days to 45 days. A fractional factorial design was applied to three levels of five factors tested in CCD (Experiment 2). Yield per hill and per unit area were examined and the results obtained from both experiments were compared. The benefits from the central composite design were discussed. Maximum yield of brown rice per unit area was obtained at the combination of the central levels of one of five factors when the other four factors were fixed at central point. Furthermore, brown rice yield per unit area affected by interaction of two factors was maximized at the central point when the remain three factors being fixed at the central level. The responses of five factors to brown rice yield per hill and unit area were found to be a saddle point in both designs. Actual values of the stationary points were 107 hills per 3.3 m2, 4 seedlings per hill, 10 kg nitrogen per l0a, transplanting date of rice on June 26 and 33 days of seedling age in the central composite design. Brown rice yield per unit area at the stationary points were estimated 439 kg/l0a in the central composite design and 442 kg/l0a in the fractional factorial design. Considering the number of experimental treatment combinations, the central composite design was rather convenient in reducing the number of treatment combinations for similar information. It was more convenient for an experimenter to present the results from the central composite design than those from the fractional factorial design. Considering the optimum yields of brown rice per unit area at the stationary points being verified as saddle points in both designs. inter-heterogeneity of each of the factors should be avoided in setting up factors in pursuit of inducing unidirectional response of the factors to yield. Even though both the lower and higher levels in the central composite design being beyond the region of an experimenter's interest. they were considered highly valued in interpretation of the results. Conclusively. the central composite design was found to be more beneficial to optimize culture condition of paddy rice even with several levels of various factors were involved.