• Journal of Environmental Science International
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• v.14 no.9
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• pp.811-815
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• 2005

The activated sludge from the aeration basin of the Su-yeong municipal wastewater treatment plant which has operated by a standard activated sludge process in Busan, Korea was investigated during April 2004 and January 2005 with several bio-indicators. The number of bacteria and fungi per gram of dry weight of MLSS were estimated to be $3.1\times10^6\sim1.5\times10^8\;and\;l.1\times10^3\sim1.1\times10^5$ colony forming units, respectively, by the plate agar method. By cultivation-independent methods, such as 4',6-diamidino-2-phenylindole stain and fluorescence in situ hybridization, the ratio of eubacteria to the entire biomass was evaluated by more than $80\%$ (v/v). The ratio of ammonia-oxidizing bacteria and nitrite-oxidizing bacteria to the total eubacteria was detennined to be $7.0\sim9.8\%\;and\;3.3\sim6.2\%$ without heavy variation in spite of a period of relatively low temperature in the basin. It would be expected that the nitrification would occur or at least co-exist throughout the year in the sludge of many municipal WWTP with influents that contain the sufficient nitrogen sources although the WWTP does not have any specialized processes for the removal of nitrogen.

• Proceedings of the KSRS Conference
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• 2005.10a
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• pp.3-6
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• 2005

In this paper, the real scenario of water situation (e.g. water management, water availability and flooding) in an irrigated rice cultivation area in Suphanburi Province, Central-West Thailand is discussed together with the NDVI time series data. The result shown is derived by our classifier named 'Peak Detector Algorithm (PDA)'. The method discriminated 5 classes in terms of irrigation activities and cropping intensities, namely, Non-irrigated, Poorly irrigated - 1 crop/year, Irrigated - 2 crops/year, Irrigated - 3 crops/year and Others (no cultivation happens in a year or other land covers). The overall accuracy of all classified results (1999-2001) is around $77\%$ against independent ground truth data (general activities or function of an area). In the classified results, spatial and temporal inconsistency appeared significantly in the Western and Southern areas of Suphanburi. The inconsistency resulted mainly by anomaly of rainfall pattern in 1999 and their temporal irrigation activity. The algorithm however, was proved that it could detect actual change of irrigation status in a year.

• Journal of Microbiology
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• v.44 no.2
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• pp.155-161
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• 2006

Comparative analysis of microbial communities in a sequencing batch reactor which performed enhanced biological phosphorus removal (EBPR) was carried out using a cultivation-based technique and 16S rRNA gene clone libraries. A standard PCR protocol and a modified PCR protocol with low PCR cycle was applied to the two clone libraries of the 16S rRNA gene sequences obtained from EBPR sludge, respectively, and the resulting 424 clones were analyzed using restriction fragment length polymorphisms (RFLPs) on 16S rRNA gene inserts. Comparison of two clone libraries showed that the modified PCR protocol decreased the incidence of distinct fragment patterns from about 63 % (137 of 217) in the standard PCR method to about 34 % (70 of 207) under the modified protocol, suggesting that just a low level of PCR cycling (5 cycles after 15 cycles) can significantly reduce the formation of chimeric DNA in the final PCR products. Phylogenetic analysis of 81 groups with distinct RFLP patterns that were obtained using the modified PCR method revealed that the clones were affiliated with at least 11 phyla or classes of the domain Bacteria. However, the analyses of 327 colonies, which were grouped into just 41 distinct types by RFLP analysis, showed that they could be classified into five major bacterial lineages: ${\alpha},\;{\beta},\;{\gamma}-$ Proteobacteria, Actinobacteria, and the phylum Bacteroidetes, which indicated that the microbial community yielded from the cultivation-based method was still much simpler than that yielded from the PCR-based molecular method. In this study, the discrepancy observed between the communities obtained from PCR-based and cultivation-based methods seems to result from low culturabilities of bacteria or PCR bias even though modified culture and PCR methods were used. Therefore, continuous development of PCR protocol and cultivation techniques is needed to reduce this discrepancy.

• Journal of Microbiology and Biotechnology
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• v.20 no.5
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• pp.853-861
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• 2010

High substrate costs decrease the profitability of polyhydroxyalkanoates (PHAs) production, and thus low-cost carbon substrates coming from agricultural and industrial residuals are tested for the production of these biopolymers. Among them, crude glycerol, formed as a by-product during biodiesel production, seems to be the most promising source of carbon. The object of this study was to characterize the mixed population responsible for the conversion of crude glycerol into PHAs by cultivation-dependent and -independent methods. Enrichment of the microbial community was monitored by applying the Ribosomal Intergenic Spacer Analysis (RISA), and the identification of community members was based on 16S rRNA gene sequencing of cultivable species. Molecular analysis revealed that mixed populations consisted of microorganisms affiliated with four bacterial lineages: ${\alpha}$, ${\gamma}$-Proteobacteria, Actinobacteria, and Bacteroides. Among these, three Pseudomonas strains and Rhodobacter sp. possessed genes coding for polyhydroxyalkanoates synthase. Comparative analysis revealed that most of the microorganisms detected by direct molecular analysis were obtained by the traditional culturing method.

• Korean Journal of Medicinal Crop Science
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• v.7 no.3
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• pp.218-228
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• 1999

This study was conducted to obtain the information on dry matter productivity in Angelica gigas Nakai for establishing the cultivation method. Cultivation methods such as direct seeding on Mar. 31, Apr. 15 and Apr. 30, and transplanting of $8^{\frac{1}{2}}$, 9, 12 months old seedling were investigated. There were similar tendencies in changes of agronomic characters for all cultivation methods. Dry weight started to increase from 120 DAS. Direct seedling showed vigorous growth for aerial part, whereas transplanting showed better underground part. The quadratic polynomial was suitable to dry weight of root after 120 DAS (or DAT) .Short growing time had higher RGR and NAR independent of cultivation method but Direct seeding on Mar. 31 and transplanting of 9 months old seedling had the highest CGRs. LAI was positively correlated with CGR, and CGR had the highest value as $6.74\g/m^2/day$ when LAI was 1.97. RGR and NAR increased as mean temperature was increased and showed the highest value around . The highest net production of leaf and petiole was obtained at 20 and$23^{\circ}C$, respectively.

• Journal of Microbiology and Biotechnology
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• v.28 no.5
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• pp.718-731
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• 2018

The beneficial effects of lactic acid bacteria (LAB) have been intensively investigated in recent decades with special focus on modulation of the host intestinal microbiota. Numerous discoveries of effective probiotics are driven by a significantly increasing demand for dietary supplements. Consequently, technological advances in the large-scale production and lyophilization are needed by probiotic-related industries for producing probiotic LAB for commercial use. Our study had a dual objective, to determine the optimum growth medium composition and to investigate appropriate cryoprotective additives (CPAs) for Lactobacillus salivarius, and compare its responses with other Lactobacillus species. The one-factor-at-a-time method and central composite design were applied to determine the optimal medium composition for L. salivarius cultivation. The following composition of the medium was established (per liter): 21.64 g maltose, 85 g yeast extract, 1.21 ml Tween 80, 6 g sodium acetate, $0.2g\;MgSO_4{\cdot}7H_2O$, $0.02g\;MnSO_4{\cdot}H_2O$, $1g\;K_2HPO_4$, $1.5g\;KH_2PO_4$, $0.01g\;FeSO_4{\cdot}7H_2O$, and 1 g sodium citrate. A cryoprotective additive combination comprising 10% (w/v) skim milk and 10% (w/v) sucrose supplemented with 2.5% (w/v) sodium glutamate was selected for L. salivarius, and its effectiveness was confirmed using culture-independent methods in the freeze-dried cells of the Lactobacillus strains. In conclusion, the optimized medium enhanced the species-specific cultivation of L. salivarius. On the other hand, the cryoprotective effects of the selected CPA mixture may also be dependent on the bacterial strain. This study highlights the necessity for precise and advanced processing techniques for large-scale production of probiotics in the food and feed industries.

• Journal of Korean Society of Rural Planning
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• v.20 no.3
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• pp.55-66
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• 2014

Under high agricultural automation in rice farming, cultivation acreage expansion can be considered for the economies of scale. Also, considering the circumstances of higher ratio in leased farms than independent farms, Long-term Leasing Business of Farmland can be the most public and transparent method to expand cultivation acreage for lease farming. Therefore, this research observes the various factors such as application motives, satisfaction, and demands of Long-term Leasing Business of Farmland, which the importance is on the rise and serves as a means to increase agricultural expansion, as well as its operational performance analysis. The research results and implications are as follows. Long-term Leasing Business of Farmland have positive effects such as ensuring stable farming through documental contract, providing convenience because the lease contractor requires no meetings during the contract period, providing opportunities to expand the farm size, and acquiring economical gain which is linked to satisfaction aspects of the businesses. On the other hand, demands such as strengthened business advertisement, writing business documents by correlating with related organizations, and clear lease price configuration were made by the businesses. To bring improvements, this research proposes; 1) expanding support to related businesses, 2) providing convenience through related organization correlations, and 3) configuring clear lease prices considering the regional conditions.

• Journal of Bio-Environment Control
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• v.7 no.1
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• pp.1-8
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• 1998

A Hardware system of hybrid environmental control was developed for using it in the multi-greenhouse. Now, an on/off control system is most utilized in protected cultivation, but a hybrid environmental control system is not yet. This system consists of a hardware to be devided by physical elements and a software for the hardware a personal computer, a hybrid environmental control and a communication Program for modules. The hardware was made of several independent modules with independent CPU. Each module was made to slots. which are very convenient to mount and take off. Also, they are managed easily to repair, add, remove, and change of their function and expansion. The software for a personal computer was a menu driven program written in visual basic within a Windows environment for easy applications by a user. The hybrid environmental control software have operating factors operate continuously with temperature, humidity and others in greenhouse. Communication programs were used both 485 communication method for long distance communication between modules and CRC communication method for making easy to program, and less errors between personal computer and modules.

• Korean Journal of Agricultural Science
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• v.20 no.2
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• pp.221-236
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• 1993

Economic conditions of Korean agriculture have been aggravated since farmers experienced the shortage of labor, instability of farm product price, lack of capital and pressure of opening domestic market. Nevertheless, agriculture must be maintained because structure of national economy can not be progressed without balanced growth of food industry. So the problem that we must solve is to keep agriculture competitive. In that case technology is important in terms of improving productivity, overcoming labor shortage and stabilizing price. This paper is to study the technology adoption on the farm level, focusing on the theories of technology adoption, their empirical test and effect of technology adoption on the farm household income. In this study five theories-independent model, linear model, middle class conservation model, modified middle class conservation model, basic needs and wealfare model- were introduced concerning differentiated technology adoption rate by farmers' class. Based on the survey of controlled strawberry farming in Nonsan County, Chungnam Province, who adopted six kinds of technology, modified middle class conservation model was found to explain five kinds of technology adoption pattern and linear model was useful to explain one kind of technology, that is, irrigation method, These results may mean that controlled strawbary cultivators of middle class were reluctant to accept new technology. There are many variables to effect on the technology accepting rate, that is, farmer's age, labor capacity, education level, cultivation career, size of total cultivated land, and size of strawberry farming land. LOGIT model was used to find which variable influence the technology adoption rate. Results of estimation showed that variables of cultivation career and total land size, of which coefficients were statistically significant at the 5 percent level, might be main influential factors in accepting more than three farming techniques. There was a significant income difference between farm households accepting new methods and those rejecting them. Especially in case of low class of farming group, income of farmers who was adopting new technology was examined to be much higher than that of farmers who did not adopt. This result suggests that new technology play an important role in increasing farm household income. Finally this study emphasized that there is a need to develop proper measure of technology transfer considering various socioeconomic conditions of farm households.

• Journal of Korean Society of Forest Science
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• v.85 no.2
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• pp.309-315
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• 1996

Selective breeding and hybridization were attempted to improve shiitake(Lentinus edodes) strains for bed-log cultivation, and the results obtained are as follows. 1. Thirty five strains collected in Korea and abroad were cultivated for one generation(five years) and fruit body yields were estimated by the amounts produced from $1m^3$ of oak tree(Quercus mongolica) logs. Thus, three high-temperature type strains including FRI 177 showing productivity of $139kg/m^3log$, two mid-temperature type strains including FRI 188 of $120kg/m^3log$, and seven low-temperature type strains including FRI 187 of $96kg/m^3log$ were selected as superior strains. 2. Twelve hybrid strains confirmed as independent strains through indoor-test with hybrid strains made by Di-mon mating method were cultivated for five years(one generation). Among them, FRI 182 and FRI 184 were turned out to be superior strains. FRI 182 of high-temperature type showed the yield of 108kg per $1m^3logs$ and FRI 184 of low-temperature type produced $103kg/m^3log$. 3. There were no significant differences in productivity among high-, mid- and low-temperature types, but some differences appeared among strain groups. The correlation was not shown in productivities between bed-log and sawdust cultivations.