• 한국환경과학회지
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• 제14권9호
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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.

• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 2005년도 Proceedings of ISRS 2005
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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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• 제44권2호
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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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• 제20권5호
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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.

• 한국약용작물학회지
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• 제7권3호
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• pp.218-228
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• 1999

참당귀의 주산지인 경북북부지역에서 재배양식에 따른 참당귀의 생장해석을 통해 얻어진 결과를 요약하면 다음과 같다. 주요형질의 변화는 재배양식에 관계없이 유사한 경향을 나타내었고 직파재배에서 파종시기가 빨라질수록 지상하부 형질은 크거나 많았으며, 이식재배에서는 지상부 형질은 관행 12개월묘보다 9개월이하 묘이식이 크거나 많은 반면 지하부 형질은 생장초기에는 묘령에 따른 차이가 있었으나 생장이 진전될수록 이러한 차이를 확인할 수 없었다. 각 기관별 건물중은 파종 및 이식 후 120일부터 증가하기 시작하였으며 직파재배의 경우 지상부 생장이 지하부에 비해 왕성한 반면 이식재배는 지하부 생장이 상대적으로 왕성하였다. 생장기간이 단축될수록 광합성기관의 분배율이 증가하였고 RGR, NAR 등 일차생산성은 증가하였으나 생장일수의 제한 및 단위면적당 일차생산성을 나타내는 CGR이 9개월묘 이식과 3월31일 직파가 가장 빨라 군락상태에서의 일차생산성은 이들 재배양식이 높은 것으로 나타났다. 참당귀의 CGR과 LAI간에는 2차 다항식이 유의하게 존재하였으며 LAI시 1.97일 때 /$6.74\;g/m^/dat2$ 로 가장 빨랐다 RGR과 NAR은$23^{\circ}C$ 경에 가장 높았고 건엽중 및 건엽병중은 각각 $23,\;20^{\circ}$에서 순생산량인 가장 많았으며 건근중은 부의 관계를 보였다.

• Journal of Microbiology and Biotechnology
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• 제28권5호
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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.

• 농촌계획
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• 제20권3호
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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.

• 생물환경조절학회지
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• 제7권1호
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• pp.1-8
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• 1998

본 연구에서는 다동온실내 작물의 생체정보와 실내외 환경요인의 정보를 얻기 위하여 복합환경제어용 시스템을 개발하였다. 이를 원예연구소에 설치하여 작동이 잘되는 것을 확인하였다. 앞으로 복합환경제어가 될 수 있도록 작물에 대한 온실의 환경 및 생체정보에 관한 연구가 필요할 것이다. 연구결과를 요약하면 다음과 같다. 1. 하드웨어는 각 기능별로 완전한 독립구조로 된 모듈형태로 구성이 되며, 각 모듈이 슬롯형태로 제작되어 수리 및 수정이 용이하고, 이동이 편리한 장점을 가지고 있다. 2 PC에서 통신을 통하여 시스템의 규모를 조절할 수 있으며, 각 입출력 단자의 기능 및 범위를 조절할 수 있다. 또한 각 제어 블록 사이에도 통신이 가능하여 유동성과 확장성이 뛰어나다. 3 환경제어 로직은 기존의 시스템에서 사용되었던 타이머를 이용한 작동기기별로의 제어가 아닌 온실전체의 온도와 습도를 위주로 하여 시퀀스 제어를 하도록 구성하였다.

• 농업과학연구
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• 제20권2호
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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.

• 한국산림과학회지
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• 제85권2호
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• pp.309-315
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• 1996

원목재배용(原木裁培用) 표고우량균주(優良菌株)를 육성(育成)하기 위해 균주수집(菌株蒐集)에 의한 선발육종(選拔育種)과 교배계(交配系)를 이용한 교잡육종(交雜育種)을 실시한 결과는 다음과 같다. 1. 국내외(國內外)에서 수집(蒐集)한 35종의 균주에 대한 원목재배를 실시하여 1세대(世代)(5년간(年間)) 버섯수확량(收穫量)이 신갈나무(Quercus mongolica) $1m^3$당(當) 139kg을 보이는 FRI 177 등 3개의 고온성균주(高溫性菌株)와 120kg을 나타낸 FRI 188 등 2개의 중온성균주(中溫性菌株) 및 96kg의 FRI 187 등 저온성(低溫性) 7개 균주를 우량품종(優良品種)으로 선발하였다. 2. Di-mon교배법(交配法)을 이용하여 제조한 교잡균주중(交雜菌株中) 실내검정(室內檢定)을 통하여 독립계통(獨立系統)으로 확인된 12균주(菌株)에 대하여 원목재배(原木栽培)를 실시하여 1세대(世代) 버섯수확량이 원목(原木) $1m^3$당(當) 108kg에 달하는 고온성균주(高溫性菌株) FRI 182와 103kg을 보이는 저온성균주(低溫性菌株) FRI 184 등 2개를 우량종균(優良種菌)으로 선발하였다. 3. 고온성, 중온성 및 저온성 등 온도형(溫度型)에 따른 생산성(生産性)의 유의차(有意差)는 없었으나, 계통간(系統間)의 생산성차이(生産性差異)는 인정(認定)되었다. 한편 원목재배(原木栽培)와 톱밥재배간(栽培間)의 생산성에는 어떤 상관관계(相關關係)도 보이지 않았다.