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        검색결과 2,030

        581.
        2014.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Membrane backwashing waste shows seasonally different characteristics and it has bad settleability differently from general backwashing waste in water treatment plant. When chemicals was injected to membrane backwashing waste, the settleability was better than chemicals was not injected. However, when settled lower sludge was not discharged, flowing sludge continuously was concentrated over a certain surface and floatation penomena occurred according to flowing velocity. When the lower sludge was discharged continuously in the thickener to prevent floatation penomena of turbidity materials, the depth of sludge surface was the least and the settleability increased.
        4,200원
        582.
        2014.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The performance of the new aerobic digestion system combined with inorganic sludge separation unit and sludge solubilization unit, CaviTec II, is evaluated. Anaerobic digester effluent sludge is used for feed sludge of CaviTec II system. By addition of CaviTec II, the amount of cake generated is reduced by 27%, and the soluble nitrogen is reduced by 92%.
        4,000원
        583.
        2014.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        우리나라 주요 항만에 규정되어 있는 정박지와 관련한 운영 세칙은 항만마다 정박지 운영 기준이나 정박지 선박수용능력에 대한 단위가 단일화 되어있지 않으며, 동일한 사안에 대해 다른 용어들을 사용하고 있다. 이로 인해 정박지를 운영하거나 이용하고자 하는 당사자들에게 큰 혼란을 주고 있는 상황이다. 본 연구에서는 국내 주요 항만의 정박지 운영 세칙을 검토하여 세칙명, 단위 및 용어의 단일화방안을 제안하였다. 아울러 정박지 운영상의 혼란을 최소화하기 위하여 외국 주요 항만의 정박지 현황 검토를 통하여 향후 세칙 개정시 정박지 명칭 부여 원칙, 정박지 선박수용능력 단위 및 정박지의 수용가능한 선박 척수의 설정이 이루어지도록 제안하였다.
        4,000원
        584.
        2014.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구는 섬유소분해 효소제를 공급수준에 따라 비육전기 및 비육후기 한우 거세우에 적용하였을 때 성장 및 도체성적에 미치는 영향을 조사하기 위하여 수행하였다. 시험동물은 비육전기 및 비육후기 거세우로 각각 54두씩 총 108두를 대상으로 하였으며, 시험 개시 시 공시된 비육전기 및 후기 거세우의 평균체중은 각각 397.4±27.2(평균 17개월령), 525.2±47.4kg(23개월령) 이었다. 시험사료는 비육전기사료와 비육후기 사료를 구분하여 대조구 사료에 섬유소분해 효소제 0.05(E0.05, L0.05), 0.15% (E0.05, L0.15)를 첨가한 비육전기 및 비육후기 각각 3처리구에 각 처리당 6마리씩 3반복으로 완전임의배치하여 실시하였다. 비육후기 한우 거세우에서 농후사료 섭취량은 대조구와 L0.15구에서 L0.05와비교하여 증가하였으며, 총 건물섭취량 역시 동일한 결과를 나타냈다(p<0.001). 반면, 비육전기 및 후기 한우 거세우 모두 증체량 및 사료효율은 유의한 차이를 나타내지 않았다. 한편 비육후기 거세우의 도체특성은 L0.05와 L0.15구에서 대조구와 비교하여 지방색이 유의하게 높은 것으로 조사되었다 (p<0.01). 등심조직의 지방산 분석은 대조구와 처리구는 유의한 차이를 나타내지 않았다. 결과적으로 본 시험에 사용된 섬유소 분해효소의 비육기 한우 거세우에 대한 첨가효과는 등심의 지방색이 짙어진 것을 제외하고 없는 것으로 나타났으며, 추후 볏짚 위주의 조사료 급여체계에서 효소제 첨가수준 및 효소역가에 대한 추가적인 연구가 필요할 것으로 판단된다.
        4,300원
        585.
        2014.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        PURPOSES : To operate more efficient traffic management system, it is utmost important to detect the change in congestion level on a freeway segment rapidly and reliably. This study aims to develop classification method of congestion change type. METHODS: This research proposes two classification methods to capture the change of the congestion level on freeway segments using the dedicated short range communication (DSRC) data and the vehicle detection system (VDS) data. For developing the classification methods, the decision tree models were employed in which the independent variable is the change in congestion level and the covariates are the DSRC and VDS data collected from the freeway segments in Korea. RESULTS : The comparison results show that the decision tree model with DSRC data are better than the decision tree model with VDS data. Specifically, the decision tree model using DSRC data with better fits show approximately 95% accuracies. CONCLUSIONS : It is expected that the congestion change type classified using the decision tree models could play an important role in future freeway traffic management strategy.
        4,000원
        586.
        2014.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Nowdays, costumer’s washing behavior were often times for remove to light-duty dirt. The purpose of this study is to provide the most effective washing conditions of detergent concentration and temperature conditions for help save energy and water resources required to the washing process. Washing conditions were as follows: 2 kinds of detergents and 4 types of artificially soiled fabrics were used. Detergent concentration was 0%, -10%, and -20% below the recommended conc. of manufacturer’s standard. Temperature of bath was 20℃ and 40℃. The results of this study were as follows: First, washing performances of all kind of artificially soiled fabric improved as the temperature of bath at 40℃. Second, the test was conducted under the condition of decreasing respectively -10% and -20% below of the recommended concentration of manufacturer’s standard detergent. The average of washing efficiency was not considerably affected by the reduction of 10% below of manufacturer’s standard. Third, in case of the water temperature were 20℃, polyester/cotton blended fiber were higher degree of washing efficiency than cotton fiber.
        4,000원
        587.
        2014.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        A pilot plant (Q=5 m3/d) study was implemented for small and medium sized personal wastewater treatment plant effluent to evaluate MBR and A/O processes utilizing self-sufficient energy composed of wind and solar energy. The removal efficiencies of BOD, SS, turbidity and color were sufficient for legal water quality standards for gray water. However, those of nitrogen and phosphorus could not meet legal regulations which suggested that further removal of those contaminants were needed for reuse of the treated water.Self-sufficient energy rate was 100 % for the pilot plant due to excessive design capacity. In this research, wind and solar energy system was applied considering geological characteristics, which significantly improved energy self-sufficiency. Substantial improvement on energy self-sufficiency can be obtained by optimized investment and operation at a full scale wastewater treatment plant.
        4,000원
        588.
        2014.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In this study, the changes in collection efficiencies due to the time changes of activated carbons were ascertained, and in order to identify the magnitude of adsorption, the before-use and after-use iodine adsorption values were analyzed. In addition, as a result of examining the characteristics of continuous process and non-continuous process and as a result of investigating whether the emission standards would be maintained, the continuous process and printing facilities were seen as not being able to maintain the emission standards. Also were found, in the case of non-continuous process,–taking into consideration the special nature of the job –for 4Ø palletized charcoal, a collection efficiency near 50% was shown even after 96 hours. Also, when the inlet concentration was about 300ppm, it is thought that the emission standards would be maintained if the activated carbons are replaced within at least 96 hours in the case of 4Ø palletized charcoal and the use was deemed pointless in the case of carbon. The results of this study are expected to provide assistance in selecting replacement periods for activated carbons and in selecting absorbents at the project sites, and are expected to be of significant help in the selection of precipitators that can collect total hydrocarbons for compliance of the emission standards.
        4,000원
        589.
        2014.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        As the users continuously play the mobile game, the mobile game service requires a method to manage their information such as their game play score and their own game items. For the purpose of responding to the user requests in real time, the proposed method reduces the size of the database by separating the information of inactive users from the main database. Considering the construction cost, the proposed method moves the information of the inactive users to the file instead of another secondary database system. In order to minimize the effect of the system environment such as CPU or memory, the proposed method depends on the response time to the user request rather than the last login time or the number of the user accounts. For the safety and consistency of the database, the proposed method utilizes a traditional RDBMS rather than NoSQL.
        4,000원
        590.
        2014.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        잔물땡땡이(Hydrochara affinis) 유충의 지하집모기(Culex pipiens molestus)와 토고숲모기 (Ochlerotatus togoi)에 대한 포식효율과 먹이선호도를 실험하였다. 포식실험에는 투명한 원통형 용기(지름 100 mm, 높이 40 mm, 수심 15 mm)가 사용되었으며, 25􀆆C에서 24시간 (16L : 8D)동안 진행되었다. 잔물땡땡이 개체당 모기 섭식 효율을 조사하기 위해 각 잔물땡땡이 유충에 대해 서로 다른 먹이조건(1, 2, 4, 8, 16, 32, 64 및 128개체)을 주었고, 각 조건별로 5회씩 반복실험 하였다. 모기유충 2종에 대한 먹이 선호도를 조사하기 위해 잔물땡땡이 1령 유충에 지하집모기와 토고숲모기 유충 32개체씩을 동시에 투여하여 5회 반복실험 하였다. 실험의 결과 모기유충 2종에 대한 잔물땡땡이 유충의 포식곡선은 로그함수의 곡선으로 나타났으며, 잔물땡땡이 유충의 영기가 증가함에 따라 포식수도 증가하는 것으로 나타났다. 포식곡선으로부터 잔물땡땡이 3령 유충의 1일 최대 포식수를 산출한 결과, 지하집모기는 926개체를, 토고숲모기는 304개체를 포식할 것으로 추정되었다. Holling’s disk equation을 이용하여 추정한 결과, 잔물땡땡이 유충의 영간, 그리고 모기유충의 종간에 모기유충 포식수의 차이가 발생하는 것은 Attack rate보다는 Handling time의 차이에 기인한 것으로 사료된다. Handling time은 잔물땡땡이 유충이 성장함에 따라 급격히 감소하였으며, 토고숲모기가 지하집모기에 비해 2배가량 길게 나타났다.
        4,000원
        591.
        2014.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        최근 식물공장 및 친환경적 농업에 대한 국내외적 관심이 증가하면서, 화훼생산에서도 환경측정센서를 이용한자동제어시스템 관련 연구들이 많이 이루어지고 있다. 특히, 토양수분센서를 이용한 자동관수시스템은 고품질 화훼류의 생산에 있어 매우 효율적이며 친환경적인 재배방법으로 현재 국내외적으로 활발한 연구 개발이 이루어지고 있다. 원예 생산에서 사용할 수 있는 토양수분 측정센서 종류로는 토양수분장력계, 석고블록, 중성자수분 측정기와 유전상수측정기 등이 있으나, 현재 가장 효율적으로 이용되는 토양수분센서는 FDR(frequency domainreflectometry) 방식으로서 이러한 센서를 이용하면 고품질의 화훼를 생산하기 위한 적정 토양수분함량 기준을 설정할 수 있을 뿐 아니라 많은 식물생육환경에 대한 연구에 명확한 기준을 제시할 수 있는 장점이 있다. 또한,자동관수시스템을 이용하여 화훼생산을 하게 되면 관수량을 절약할 뿐 아니라, 비료 비용을 절약할 수 있고, 병충해를 줄이며, 고품질의 화훼작물을 생산해내며, 균일한 생장을 통해 생육시기를 줄이는 결과를 가져올 수 있다. 이를 통해 농가에서는 고품질의 화훼작물을 생력적으로 생산해낼 수 있으며, 소득을 증대시키고, 환경오염도 줄여줄 수 있는 장점이 있다. 본 논문에서는 토양수분센서를이용한 자동관수시스템에 대한 개요, 제작 방법 및 실제활용에 대해서 논하였다.
        4,000원
        592.
        2014.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Advanced Safety Management System(SMS) of Korea Railroad Corporation for risk management should be established applying contents-centered domestic standard according to Railway Safety Act and process-centered international standards suggested by Lloyd's Register Company. Besides, laws, regulations, guidelines and manuals which are optimized for each sector should be systematically integrated to strengthen the consistency of SMS of KORAIL. New safety regulations and guidelines for safety management/train operations/maintenance should be established according to the safety policy of KORAIL to boost effective field work by regulations, guidelines, manuals, etc. The advanced Safety Management System will lead KORAIL as a competent global enterprise with its boosted reputation in the international railway market.
        4,000원
        596.
        2014.05 KCI 등재 구독 인증기관 무료, 개인회원 유료
        중소기업 R&D지원은 정책적으로 매우 중요하며 예산 또한 매년 증가하고 있다. 본 연구에서는 중소기업 R&D지원에 대한 성과를 종합적이고 체계적으로 분석할 수 있는 새로운 성과분석 방법을 제안하며 이 모델을 기반으로 중소기업청의 대표적인 R&D지원사업에 대하여 실증분석하였다. 중소기업 R&D지원사업의 성과는 시차(time-lag)를 두고 발생하는데 이때, 단기적인 성과를 효율성, 중․장기적인 성과를 효과성으로 측정하였다. 효율성과 효과성을 나타내는 지표는 과거 선행연구를 기반으로 선정했으며 분석대상 사업별 사업목적, 취지, 내용 등의 특성을 반영하기 위해 지표별 가중치를 도출하였다. 이렇게 효율성과 효과성의 최종 점수가 도출되고 각 사업별 성과의 차이를 통계 검정하였다.분석 결과, 중소기업청의 5개 R&D지원사업의 효율성은 통계적으로 유의한 차이를 나타냈으며 효과성은 통계적으로 차이가 없었다. 효율성 점수는 전반적으로 낮게 나타나며 효과성 점수는 보통이상으로 높은 수준을 보였다. 중소기업청의 R&D지원사업은 대체로 단기적인 성과인 효율성이 낮아 R&D수행상의 비효율을 초래하는 것으로 나타나는 반면, 중․장기적인 효과성에 대한 기대는 높아 R&D수행을 통한 사회경제적 파급효과는 클 것으로 예상된다. 그러나 효율성이 개선되지 않고는 지속적인 성과를 기대하기 힘들기 때문에 이에 대한 정책적 노력이 필요하다.
        6,700원
        597.
        2014.05 구독 인증기관 무료, 개인회원 유료
        The government expands its investment on R&D programs for economic growth, thus there are growing attention on the result of R&D programs. However, our existing research is in the circumstance of only measuring efficiency, but not reflecting unique characteristics of R&D programs. In this study, it provides more developed method for efficiency analysis in national R&D programs by using partial efficiency concept and measuring influence of input factors. It analyzes the influence of each input factor on efficiency by using partial efficiency concept. And it also determines input factors in similar influence throughout Spearman correlation coefficient. Finally, it suggests new method to improve discriminatory power of efficiency analysis by determining representative factors.
        3,000원
        598.
        2014.05 구독 인증기관 무료, 개인회원 유료
        Most of metal cutting and processing companies are frequently used to mass-produce defectives by missing times to replace parts of CNC equipment. The reason is that the correct operation times of expensive CNC equipment can’t be calculated. In this paper, to solve these problems, we construct the intelligent production information system and analyze the expected effects.
        4,000원
        599.
        2014.04 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Immobilization of anaerobic ammonium oxidizing bacteria has been studied to enhance the biomass retention of the slowly growing bacteria and the process stability. The purpose of this study was to compare the nitrogen removal efficiency of granular and immobilized anammox bacteria with poly vinyl alcohol and alginate. The specific anammox activity of the granular, homoginized and immobilized anammox bacteria were 0.016±0.0002 gN/gVSS/d, 0.011±0.001 gN/gVSS/d and 0.007±0.0005 gN/gVSS/d, respectively. Although the activity decreased to 43.7 % of the original one due to low pH and O2 exposure during the homogination and the immobilization, it was rapidly recovered within 7 days in the following continuous culture. When synthetic T-N concentrations of 100, 200, 400, 800 mg/L were fed, the immobilized anammox bacteria showed higher nitrogen removal efficiencies at all operational conditions than those of granular anammox bacteria. When the sludge retention time was shorten below 30.7 days and the reject water was fed, the nitrite removal efficiency of the granular anammox bacteria dropped to 8 % of the initial value, while that of the immobilized anammox bacteria was maintained over 95 % of the initial one. The immobilization with poly vinyl alcohol and alginate would be a feasible method to improve the performance and stability of the anammox process.
        4,300원
        600.
        2014.04 구독 인증기관 무료, 개인회원 유료
        As Internet has been wildly spreaded and it's technique is advanced, the use of computers has been routinized and almost data are stored in computers. Accordingly, many companies and researchers have tried to find the relations in these tremendous data and the one way is to use clustering algorithm which is used to find out similar data set in the entire data set and to discover the common properties. In early period, clustering algorithm was performed based on a main memory of a computer and PAM(Partitioning Around Medoids) was representative, which can be complemented k-means algorithm defeat. PAM performs clustering by using the medoid of data instead of means. PAM works well in small data set but it is difficult to apply it to large data set. Therefore, CLARA(Clutering LARge Application) shows up to be used in large data set. This algorithm samples data from large data set and applies PAM to the sample data. CLARA has limits caused by the fixed samples in each clustering stage and has a problem that if the good mediod is not sampled then the result of the clustering becomes not good. CLARANS(Clustering Large Application based upon Randomized Search) overcomes these problems by drawing a sample with some randomness. This algorithm executes clustering using k mediod set extracted in the processing of clustering in each stage. The main objective is to compare and analyze the algorithms which are popularly used for the clustering of big data.
        4,000원