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        검색결과 33

        2.
        2019.04 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구의 목적은 양돈 농장 관련 차량 이동 데이터를 활용해 농장과 도축장 간 네트워크 분석을 수행하는 데 있다. 구제역과 같은 확산 속도가 빠른 질병에 효과적으로 대응하기 위해서는 초동대응 및 선제적 차단방역이 중요하다. 이러한 방안을 마련하기 위해서는 질병 전파의 주요 매개체인 차량 이동 분석 및 질병이 확산되는 장소인 도축장과 양돈농장의 연계 관계에 대한 분석이 요구된다. 본 연구에서는 KAHIS(국가가축방역통합시스템, Korea Animal Health Integrated System)가 관리하는 차량 이동 데이 터를 기반으로 농장과 도축장 간 바이너리 매트릭스를 생성해 농장과 도축장 간 네트워크 분석을 실시하였다. Rasch model 및 Latent Class Analysis(LCA) 방법을 활용해 농장과 도축장의 위험도를 산출하고, 농장을 군집화하였다. Rasch model 분석 결과, 전라북도와 경기도 농장이 높은 위험도를 보였으며, 이는 질병 전파의 위험도가 높은 것으로도 해석 가능하다. LCA를 활용한 군집 분석 결과, 총 7개의 군집으로 분류되었다. 특히, Rasch model에서 추정된 위험도의 고려했을 때, 4번 군집이 중점적으로 관리되어야 할 대상인 것으로 나타났다. 그 다음으로는 위험도가 0.02수준인 1, 3, 5, 6번 군집이 주의해야 할 대상으로 나타났다. 위험도가 상대적으로 낮은 2, 7번 군집의 경우, 도축장을 통한 질병 전파 위험도는 낮은 수준인 것으로 해석 가능하므로 군집 단위의 관리보다는 개별 농장 단위의 모니터링 관리를 고려해볼 수 있다. 본 연구 결과에서의 양돈 농장과 도축장 간 군집 분석 결과를 고려한다면 김제, 고창과 인접한 정읍, 부안, 익산을 이어서 논산과 공주까지의 전북, 충남의 일부 지역에 대해서만 이동제한을 연장하는 세밀한 방역조치를 생각해볼 수 있었을 것이다.
        4,200원
        3.
        2017.04 KCI 등재 구독 인증기관 무료, 개인회원 유료
        연구에서는 펄프공정으로부터 배출되는 리그닌 추출물 내의 금속이온분리를 위한 연구를 진행하였다. α- Alumina 분말에 DMAc (N,N-dimethylacetamide) 용매와 PESf (Polyethersulfone) 고분자를 혼합하고 PVP (Polyvinylpyrrolidone) 분산제를 첨가하여 슬립 캐스팅 방법으로 분리막을 제조하였다. 분리막은 CFP (Capillary Flow Porometer) 장치 를 통해 기공크기를 측정하고 FE-SEM (Field Emission Scanning Electron Microscope) 장치를 이용하여 실제 분리막 표면과 단면을 관찰하였다. 플럭스는 분리 실험장치를 이용하여 시간당 여과된 무게를 측정하여 계산하였다. 기공크기측정은 0 psi에 서 30 psi까지 서서히 증가하는 승압조건에서 진행하였다. 분리막의 기공크기는 0.4 μm 크기를 가지며 플럭스는 분리막의 파 울링에 의해 초기 플럭스 값인 6.36 kg⋅m-2⋅h-1에서 1.98 kg⋅m-2⋅h-1으로 감소하여 3시간 이후부터 일정해지는 것을 확인 하였다. 투과 실험 후 막 오염물질은 간단한 세척을 통해 제거 가능하였다. 분리실험을 통해 초기 리그닌 추출물 내에 포함되 어 있던 Na은 69%만큼 줄었고, Fe은 87%, K은 95%, Ca은 93%, Mg은 96%만큼 제거됨을 보였다
        4,000원
        4.
        2007.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        PAHs는 해양환경 중에 넓게 분포되어 있으며 인간활동에 의한 화석연료 이용으로 PAHs의 오염이 광범위하게 일어나고 있다. PAHs는 잠재적으로 해양 수서환경 생물에 발암성과 돌연변이를 일으키고 있다. 본 연구는 여수화학공단, 광양제철소와 콘테이너부두가 자리잡고 있는 광양만의 표층퇴적물에서의 PAHs를 Soxhlet Extractor를 이용하여 추출하여 GC-MS로 PAHs 13종을 검출하였고 TOC(Total Oragnic Carbon)와 입도분석을 행하였다. 분석된 퇴적물에서 PAHs 화합물 모두가 검출되었으며 Total PAHs 범위는 171.40~1013.54μg/kg dry wt.로 검출되었다. PAHs 화합물중 Naphthalene이 14.08~691.39μg/kg dry wt.로 거의 모든 시료에서 가장 높게, Anthracene이 0.49~22.66μg/kg dry wt.로 가장 낮게 나타났다. Total PAHs와 PAHs 화합물의 상관관계는 Naphthalene, Phenanthrene과 같은 저분자량 물질에서 높은 상관관계를 나타내었다. P/A(Phenanthrene/Anthracene)비 와 F/P(Fluoranthene/Pyrene)비의 결과에 의하면 연소기원과 유류오염 기원의 복합적인 영향을 받는 것으로 보여진다. Total PAHs와 TOC와의 상관계수는 높지는 않지만 양의 상관관계를 나타내었으며, 입도와의 상관관계는 높지는 않지만 퇴적물 입자의 크기가 세립 할수록 PAHs와 상관관계가 있음이 나타났다. 광양만 표층퇴적물에서 PAHs의 검출농도는 생물학적 영향에 대한 기준(biological effect guidelines)에 비해 낮은 값을 보여주고 있다.
        4,300원
        6.
        1991.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Seawater temperature, salinity, dissolved oxygen, nutrients and chlorophyll-a have been studied around Hamduck in the northern part of Cheju Island during July, 1989-July, 1990. In the surface water ranges of water temperature, salinity, dissolved oxygen, nitrate, phospate, silicate and chlorophyll-a have been 13.7-26.5℃, 28.51-34.37‰, 4.47-7.14㎖/ℓ, ND-15.42㎍-at/ℓ, ND-1.47㎍-at/ℓ, 2.33-24.1㎍-at/ℓ, and 0.02-2.24㎎/㎥, respectively. Yearly mean values of the near surface waters(0m-10m)at station 6 show high temperature, nitrate, chlorophyll-a, while the values of dissolved oxygen, phosphate, and silicate were low compared with the other stations. The vertical profiles are likely to show the possibility of upwelling in October and tidal front in July, suggesting high productivity of phytoplankton around St.6. N1P ratio varies from 35 inshore to 15 offshore and from 45 in July to 15 in Ferbruary. These variation patterns are similar to those of water temperature.
        4,000원
        7.
        1989.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        1987년 6월-1988년 4월까지 격월로 제주도 해안선주변 10개 정점에서 부유성 갑각류의 현존량과 생산량을 야간채집, 조사하였다. 계절별 평균개체수는 12월에 가장 낮고, 6월에 가장 높았는데, 이들 개체의 대부분(90% 이상)은 90μm 망목의 네트로 채집된 것으로 이뤄졌다. 계절별 평균 현존량의 범위는 6.6-55.0mgm^(-1)(평균 16mgm^(-3))이고, 여름에 높았다. 일일평균 생산량 역시 여름(369μgCm^(-3)d(-1))에 높고 겨울(112μgCm^(-1)d^(-1))에 낮았다. P/B의 비(평균 0.25)는, 수온이 높고 소형 동물플랑크톤의 개체수가 많은 계절에 높은 값을 나타냈다.
        4,000원
        8.
        1989.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The primary production at 10 stations around the coast line of Cheju Island has been investigated from the viewpoint of standing crops(cells/e), chlorophyll-a concentration and CO₂ fixation of phytoplankton during the period from June, 1987 to March, 1989. Phytoplankton standing crops ranged from 2,025 to133,734 cells/ethrough the year, increasing from June and showing a peak in August. The distribution of standing crops was the highest in the eastern area and the lowest in the northern area. Chlorophyll-a concentration ranged from 0.45 to 2.59 ㎎/㎥ during the study period, which was much lower than that in the other Korean coastal waters. To estimate the CO₂ fixation of phytoplankton, daily primary production (㎎C/㎥/day) has been determined using C-14 method. It ranged 1.31-7.15, 34.54117.04, 22.283.64, 8.53-11.95㎎㎎/㎥/㎥/day in winter, summer, fall, and spring, respectively, and showed the highest in the western area. The carbon assimilation number(㎎C/㎎ chl-a/hr)was also higher in summer than in other seasons. The general characteristics of primary production of phytoplankton around the coast line of Cheju Island was high in the eastern and western regions during the summer season.
        4,000원
        9.
        1989.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In order to know sea water characteristics around coast line of Cheju Island, physical and chemical environmental factor analyses have been performed with data observed from June 1987 to April 188. Water temperature was over 10℃ even in winter with highest value of 14.7℃ in the southern part over the whole study area. Concentrations of DO, COD and SS were as low as those in the standard sea-water-quality classes [I] and [II]. Nutrient concentration was higher in the present study region than on the coastal areas by previous works, suggesting influx of materials from land. The ratio of N/P ranged from 21.6 to 67.4 (mean : 38.8). Concentration of Chlorophgll-a was high in eastern and southern part throughout the year, except a special high value of 3.89㎎/㎥ at Gosan, western part of the study area, in August.
        4,000원
        10.
        2015.11 서비스 종료(열람 제한)
        폐기물 에너지는 사업장 또는 가정에서 발생되는 가연성 폐기물을 가공처리하여 얻어지는 고체, 액체, 기체 형태의 연료와 이를 연소 또는 변환시켜서 발생되는 열, 온수, 증기, 전기 등과 같은 에너지를 의미하는데, 대부분의 폐기물에너지는 고형연료 및 소각에 의한 열, 온수 증기의 형태로 얻어진다. 이는 폐기물이라는 연료로서의 불균일성, 가공제품의 품질관리의 어려움에 기인된다. 한편 폐기물은 발생처가 널리 분포되어 있어 수집에 어려움과 지역 이기주의로 인해 발생처 처리가 최적 방법이다. 또한 에너지 자립섬 사업 및 분산형 발전에 연료로서 가연성폐기물의 사용 가능성이 대두되고 있다. 본 연구에서는 전원망이 구축되지 못한 섬지역이나 개도국의 마을단위 또는 산업체에서 독립적으로 운영이 가능한 폐기물 발전 시스템의 개발이 주목적이었으며, 고정층 가스화 반응기 및 가스엔진을 채택 module화하였으며, 반응기 운전을 통해, 가스화 반응기 내부가 4개의 반응zone(Combustion, gasification, pyrolysis, drying)으로 운전될 때, 가스엔진 구동이 가능한 합성 가스가 생성되며, 반응 Zone의 형태 유지 방법에 따라 합성가스 조성이 달라진다. 휘발분이 10%이상 되는 목질계 바이오매스를 공기로 가스화 하였을 경우 1,200kcal/Nm3의 발열량을 갖는 합성가스를 생성할 수 있었으며, 가스엔진 구동에 의한 분산 발전 설비로의 이용이 가능하다. 또한 본 기술 개발에서 채택된 metal foam 촉매를 이용한 tar 제거 시스템은 합성가스의 가스엔진 구동을 가능하게 하여 30%정도의 효율을 나타냈다. 이러한 합성가스 엔진 발전 시스템은 가연성 폐기물로부터 분산형 발전 시스템에 적용 가능한 발전 방식임을 확인되었다.
        11.
        2013.11 KCI 등재 서비스 종료(열람 제한)
        This paper focuses on the impacts of waste dumping on inorganic nutrients in the dumping area of the Yellow Sea, and the effect of an governmental regulation of pollution in dumping areas. The environmental variables and parameters of the dumping and reference areas in the Yellow Sea were measured during July 2009 and analyzed. In addition, the analyzed data for inorganic nutrients over the last 10 years were obtained from the Korea Coast Guard (KCG) and the National Fisheries Research and Development Institute (NFRDI). The chemical environment of the study area revealed increases in concentrations of inorganic nutrients, Chemical Oxygen Demand (COD), and Volatile Suspended Solids (VSS) in the bottom layer. On the contrary, the pH level was decreased. Most notably, the time series data of inorganic nutrients showed gradual increase over time in the dumping area, and thus, the oligotrophic waters trend toward eutrophic waters. The increases appears to be due to the disposal of large amounts of organic waste . In recent times, the wastes disposed at the area were largely comprised of livestock wastewater, and food processing waste water. The liquefied waste, which contains an abundance of nutrients, causes a sharp increase in concentrations of inorganic nitrogen in the dumping area. On the one hand, the dumping sites have been deteriorated to such an extent that pollution has become a social problem. Consequentially, the government had a regulatory policy for improvement of marine environmental since 2007 in the dumping area. Hence, the quality of marine water in the dumping site has improved.
        12.
        2013.07 KCI 등재 서비스 종료(열람 제한)
        The aim of this study was to investigate the accumulation of metallic elements and the control effect of marine pollution caused by ocean dumping in the sediments at a waste disposal area in the Yellow Sea. In July 2009, concentrations of organic matter and metallic elements (Al, Fe, As, Cd, Cr, Co, Hg, Ni, Mn, Pb, and Zn) were measured in surface sediments at the site. The ignition loss (IL) in the surface sediments showed a mean value of 15.4%, about 1.5 times higher than the mean value of the sediments in the coastal areas of Korea. The chemical oxygen demand (COD) at some disposal sites exceeded 20 ㎎ O2/g·dry, which signifies the initial concentration of marine sediment pollutants in Japan. The disposal sites contain higher concentrations of Cr, Cu and Zn than the sediments of bays and estuaries that might be contaminated. The magnitude of both metal enrichment factors (EF) and adverse biological effects suggest that pollution with Cr and Ni occurred due to the dumping of waste in the study area. In addition, the geoaccumulation index (Igeo) showed that the surface sediments were moderately contaminated. By the mid-2000s, when the amount of waste dumped at this site was the highest, the concentration of metallic elements was higher than ever recorded. On the other hand, in 2008-09, the need for environmental management was relatively low compare with the peak. As a result, the quality of marine sediment has been enhanced, considering the effect of waste reduction and natural dilution in the disposal area.
        14.
        2009.12 KCI 등재 서비스 종료(열람 제한)
        This study reviews and modifies general IS success models to find success factors of WIS(Web-based Information Systems) and to confirm the relationship between WIS success and user's satisfaction of web use. A WISSM(Web-based Information Success Model extended to include EQ(E-Quality) is developed to anticipate user's intention to use Web-based Agricultural Information System and fit into the survey data from 252 WIS users of RDA(Rural Development Administration). PLS is applied to estimate a structural model based on EQ-WISSM to test hypotheses including 1) users reach a high level of intention to use Web-based Information Systems when they feel a high level of interactivity among an 'E-Quality', 'Decision Making Support Satisfaction' and 'Task Support Satisfaction', and E-Quality boosts intention to use Web-based Information Systems. The results show high path coefficients and R2 values and find followings; First, the EQ-WISSM explains the user's intention to use WAIS quite well. Second, E-Quality can be used well in web-based IS environment to predict IS Success. Finally, this research finds the importance of 'Task Support Satisfaction' as a mediator between 'Decision Making Support Satisfaction', 'E-Quality' and 'Intention to Use'.
        15.
        2008.08 KCI 등재 서비스 종료(열람 제한)
        The purpose of this study is to analyze the determinants of the digital divide at individual level and regional level in Korea, considering interaction between individual and the regional variables. Following results are obtained. First, individual level digital devide in the 16 different regions has been found in terms of Internet use, implying the needs for further analysis on impact of the regional factor in individual Internet use. Second, the result finds the impact of level-l individual variables, "gender, age, education, income and jobs" on digital divide, significantly at level 10% level. Third, the regional variables influencing the individual digital divide were not found at state level. However, regional factors might affect digital devide at county level. Study suggest some plans to reduce digital divide. First, the digital devide at individual level should be remedied by focusing on neglected class of people. Second, we need to approach the digital divide by analyzing in more detail, reflecting interactions of the regional variables and individual variables. Third, we should come up with a policy for mending the digital divide at regional level.
        16.
        2008.03 KCI 등재 서비스 종료(열람 제한)
        This study deals with shopping value and trust as the factors to influence consumer attitude and purchase intention in online shopping. Utilitarian and hedonic shopping values, trust, attitude and purchase intention are incorporated into the Value-Attitude-Behavior model to find out how differently shopping values and trust influence online shoppers attitude and purchase intention when they have different purchase experiences. Data are collected from survey of 187 subjects and divided into two groups according to their online purchase experiences : 97 shoppers with low online purchase experiences and 89 with high experiences. PLS(Partial Least Square) method is applied to estimate the research model and to test 7 hypotheses. The results show the difference of the way how shopping value and trust influence purchase intention. In the case of low experienced online shoppers, trust has the greatest influence purchase intention, followed by hedonic shopping value mediated by attitude. However utilitarian shopping values have a bigger impact on it for shoppers with high purchase experiences. In the latter, trust also has a significant impact on purchase intention at confidence level of 0.05. The results also provide useful implications for practitioners to build and manage their marketing strategies. Managers of online shopping mall should react to the different shopping value by shopper's experience.
        17.
        2007.12 KCI 등재 서비스 종료(열람 제한)
        This study analyzed the probability that experiment stations, agricultural technology and extension centers, provincial agricultural research and extension services, central government organs, or civilian and other related organs will be the first choice of the compositional subjects of local innovation networks. While gender effect was statistically insignificant, educational level, income, main acquired information, sources of necessary information, and frequency of information acquisition sessions were significant, and the preference ranking model was highly relevant. According to the analysis, highly academic and business-related information was most likely to be acquired from the civilian sector; agricultural technology such as technology, crops/plants, storage, and circulation was most likely to be acquired from experiment stations and provincial agricultural research and extension services; and information on agricultural production was most likely to be acquired from agricultural technology centers.
        18.
        2007.03 KCI 등재 서비스 종료(열람 제한)
        This study examines empirically the characteristics of agricultural corporations in terms of their market and technology environment and the efficiency of the governmental support to the firms. Also the study analyzes the moderating effect of the environmental characteristics on the relationship between governmental supports and firm performance based on the concept of balanced performance. Test results show that firm tend to evaluate favorably their technology and market competitiveness of product quality and price and to require tools for reaction to changes of customer needs and technology or competing products and external corporation that is necessary for long-term technological competitiveness. As for governmental support, strategic support and service is much more appreciated than direct individual supporting item. Agricultural corporations with unfavorable market environment evaluate relatively high on their balanced performance. Correlations of balanced performance factors and technology environmental factors show all positive statistical significance. The moderating effect of the environmental characteristics on the relationship between governmental support and balanced performance can be interpreted that the support is provided without considering environmental aspect and based only on financial performance and as a result not to be satisfied by agricultural corporations with technological competitiveness.
        19.
        2005.12 KCI 등재 서비스 종료(열람 제한)
        Butyltin compounds (BTs), namely tributyltin (TBT), dibutyltin (DBT) and monobutyltin (MBT), were measured in surface and core sediments collected in 2001 inside Seogwipo Harbor, in order to evaluate their distribution characteristics. Seogwipo Harbor is one of major harbors of Jeju Island where a lot of shipping occurs and is designated as a trade port by the Korea Maritime and Port Law. BTs were detected in surface and core sediments of all stations and their concentrations in surface sediments were low, compared with to those in other sites of domestic and foreign countries. The main species among BTs was MBT, although there was a little difference with a survey site in surface sediments and in core sediments with depth. No or low correlations were obtained between organic matter or particles size of surface and core sediments and total BTs, indicating that these factors did not affect the distribution of BTs. It was estimated that more complex factors including BTs loads and surrounding sedimentary environments, affect the distribution of BTs. The high correlations between BTs indicated that DBT and MBT were mainly degraded from TBT based on antifouling paints of vessel etc. and other sources, such as DBT and MBT, could be ignored. The butyltin degradation indices ([DBT] + [MBT]/[TBT]) in surface sediments were in the range of 2.0~3.8 (mean 3.0), indicating that the parent compound, TBT, were inflowed into the surface sediments a long years ago, degraded and deposited. The sedimentation age of BTs contaminated core sediments could not estimated because the content of 210Pb activity were nearly all the same and so the sedimentation rate could not obtained.
        20.
        2005.12 KCI 등재 서비스 종료(열람 제한)
        This study designs an integrated data architecture to systematically manage the agricultural statistics database. Managing the agricultural statistics is important since it provides data for policies and decision making for agribusinesses. Ministry of Agriculture and the National Statistical Office collect the basic agricultural statistic data which provides the basis of logical decision making and agricultural policies. However, the agricultural statistic data has not well been used. The data has not been consistently collected nor managed. The raw data has not been organized nor processed to meet various demands. The needs has been arisen for a consistent agricultural statistics system to increase the relevance, accessibility, and efficiency of data for various users. There are massive amount of data accumulated over a long time period. Introducing the new system and reorganizing the data will bear large risks. A systematic method is required to reduce the risks in planing, building, and maintaining the database without hindering administration. This study provides a design of the agricultural statistics system architecture based on the user requirement analysis (URA) and similar systems abroad. We have also build a prototype to check the implementability of the system design.
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