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        검색결과 104

        41.
        2005.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Line capacity calculation has been used to determine optimum efficiency and safe train service for train scheduling plan and investment priority order throughout detecting bottleneck section. Because of some problems of Yamagisi and UIC methods for line capacity calculation, developing of the method of line capacity caculation and evaluation for the Korea circumstance is important. This paper deals with the reliability improvement on the integrated system of TPS(Train Performance Simulator), PES(Parameter Evaluation Simulator), LCS(Line Capacity Simulator) and simulation and sensitivity analysis for line capacity.
        4,200원
        42.
        2005.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        There are very large differences on the standards of gross weight and single axle weight for commercial motor vehicles between international and Korean standards. Short Wheelbase Truck are produced and run only in Korea. It has very serious effects on the durabilities of bridges and roads and makes logistic competitive power fall back and overconsuming energy. This paper deals with a comparative study of the international standards with Korean, grasps the drawbacks and makes up the suggestions to strengthen the logistic competitive power of Korea and reduce the maintenance cost for the roads and the consumption of energy.
        4,000원
        43.
        2005.05 구독 인증기관 무료, 개인회원 유료
        There are very large differences on the standards of gross weight and single axle weight for commercial motor vehicles between international and Korean standards. Short Wheelbase Truck are produced and run only in Korea. It has very serious effects on the durabilities of bridges and roads and makes logistic competitive power fall back and overconsuming energy. This paper deals with a comparative study of the international standards with Korean, grasps the drawbacks and makes up the suggestions to strengthen the logistic competitive power of Korea and reduce the maintenance cost for the roads and the consumption of energy.
        4,000원
        44.
        2004.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        최근 콘크리트 균열선단에서 균열의 발생을 억제하거나 균열 발생시 균열폭을 제어하고 일정부분 하중저항 능력을 향상시킬 목적으로 다양한 형태의 강섬유(Steel Fiber)를 혼입하는 방법이 개발되어 사용되고 있다. 강섬유 보강 철근콘크리트보(SFRC; Steel Fiber Reinforced Concrete)의 복잡한 파괴역학적 성질에 의한 불확실성 통이 내재되어 있다. 본 연구에서는 SFRC보의 불확식성을 고려하는 신뢰성 해석을 수행하였다. 이를 위해 강도 한계상태모형을 제시하였고, 한계상태함수에 포함된 각종 확률변수들에 대한 통계적 특정값을 국내외 관련 문헌을 근거하여 수집, 제시하였다. 향후 추가적인 관련정보가 수집되면 보다 개선된 통계적 특성값을 제공 할 수 있도록 Blayseian Updating 기법을 사용하여 실험결과로부터 불확실성을 개선하는 과정을 제시하였다. 뿐만 아니라 피로신뢰성의 해석을 위해 피로파괴확률식을 제안하고 필요한 통계적 특성 값을 제시하였다.
        4,000원
        45.
        2004.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This development has tried to scheme out the convenience for users to use the 3D modeling solution which is developed from the existing programs. The extended 3D modeling solution, to be developed through the use of the API which is provided and Microsoft Access, database is able to reuse the parts, subassemblies of parts, and assemblies. A methodology exhibits the possibility to use a Spinfire Professional Spinfire Reader program. The web evaluation system, which is used to connected with the Internet explorer and to construct a web service, will repeat the evaluations of the company staffs and customers about the new products which the company have designed. The furniture manufacturing company will adopt the 3D modelling solution in modelling the new products and go through the web evaluation system to collect dissatisfied facts of the customers or the company staffs against the new product. Finally, it will contribute to the enormous benefit creation of the enterprise.
        4,300원
        46.
        2004.11 구독 인증기관 무료, 개인회원 유료
        A purpose of this research is building a Parameter Evaluation Simulation(PES) program which is present proper parameter value to calculate line capacity. This research performs a detailed simulation and a analysis of it using PES and it is developed on the basis of Line Capacity Simulation model. Chosen simulation sectors are that happened a big change of a line capacity because of joining a high speed train(KTX). Moreover this research performs a sensitivity analysis when basic data are changed.
        4,000원
        49.
        2002.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Nowdays cyber education based on the internet is actively developed. But the management of the customers in the cyber education field is not enough. Then, in this paper, we provide the learner with the proposals of lectures to be extremely matched by analyzing the learning capacity and the greatest concern of him(her) using the methods of data mining, such as RFM, prediction, slickness, association rule, classification, and so on.
        4,000원
        50.
        2002.05 구독 인증기관 무료, 개인회원 유료
        인터넷을 기반으로 하는 사이버교육은 활발 전개되고 있다 하지만 사이버교육에서의 CRM 적용사례는 부족한 현실이다. 본 연구는 RFM, Prediction, 고착도, 연관규칙, 분류규칙등 데이터 마이닝기법들을 활용하여 학습자의 수준에 맞는 강의추천전략을 제안했다.
        4,000원
        53.
        1994.12 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        강도, 소전율, 스프링성, 내열성 및 굽힘 가공성등의 적절한 조화를 갖는 콘넥팅재료를 개발하기 위하여 Cu-Ni-Si-P합금에 대하여 연구하였다. Ni와 Si의 조성을 달리한 3종류의 합금을 용해, 주조하여 약 900˚C에 열간압연 후 수냉하고, 그 후 냉간압연하여 450˚C. 500˚C 및 550˚C에서 시효처리한 후 기계적 성질 변화와 도전율 등을 조사하였다. 고강도와 고존도율의 적절한 조화를 나타내는 Cu-2.7%Ni-0.53% Si-0.029%P 합금을 만들었다. 합금 1을 0.5mm두께의 콘넥팅재료로 가공한 후 여러가지 특성은 인청동(C 5210R-H)과 황동(C2600R-EH)에 비해 우수한 것으로 평가되었다.
        4,200원
        54.
        2019.02 KCI 등재 서비스 종료(열람 제한)
        기후변화 적응과정에서 도입 작물의 국내 재배실태를 조사하고 대응과제를 도출코져 본 연구를 수행하였으며, 그 결과는 다음과 같다. 도입 열대·아열대 채소 재배현황(2015년 기준)은 18작목으로 재배농가수는 920농가, 재배면적은 321 ㏊로 조사 추정되었고, 재배면적이 많았던 작물은 울금, 여주, 아스파라거스, 삼채, 허브류 순이었다. 도입 열대·아열대 과수류 재배현황은 2015년 국내재배 농가수와 재배면적은 264농가 106.5㏊로 추정되며, 전년대비 각각 51.7%와 83.7% 증가하였다. 도입 특약용작물 재배현황(2015년 기준)은 10작물로 753농가에서 재배면적 276.3 ㏊로 조사 되었으며 재배면적이 많았던 작물은 강황, 감초, 마카, 모링가, 포포나무 순이었다. 도입 열대· 아열대 작물의 국내 재배가 안정적으로 정착되기 위해서는 국내 재배적응성 검정에 의거 재배환경면에서의 안전성과 경제성이 있어야 하며, 생산물의 이용과 유통 및 판로의 확보 문제, 외국현지 수입산과의 경쟁력 등을 고려할 필요가 있고, 국가 간 이동에 따른 생물다양성협약 등 국제협약 및 국내 종자산업법에 의하여 도입되어야 할 것이다.
        55.
        2019.02 KCI 등재 서비스 종료(열람 제한)
        Background: Various Schisandra chinensis (SC) varieties grow in diverse regions in Korea. However, there is no valid scientific evidence of these varieties. This study aimed to select the excellent resources in terms of the growth characteristics, antioxidant activities, and analysis of the active compounds of the SC collection. Method and Results: In total, 154 resources of SC were collected from various regions of Korea. The growth characteristics were measured by the number of fruit bunches, fruit number, and weight of 100 fruits. The antioxidant activities were investigated by analyzing the total flavonoid and total polyphenol contents and the radical scavenging activity of DPPH and ABTS. Schizandrin A, schizandrin c, gomisin a, and gomisin N were analyzed by HPLC. Each resource showed different growth characteristics. Among the antioxidative effects, the highest 20 resources showed high antioxidant activities in selected 29 resources. Analysis of the SC lignan index showed that all resources contained more than 1.16% of active compounds. Conclusions: All of the selected 29 SC resources were shown to have excellent growth characteristics, antioxidant activities, and bioactive compound richness. Especially, SC-004, SC-007, and SC-154 showed the best growth characteristics, and SC-22, SC-40, and SC-45 showed the best antioxidant activities and bioactive compound richness.
        56.
        2018.10 서비스 종료(열람 제한)
        Background : Rehmannia glutinosa root has been commonly used as traditional medicine in Korea. This root including prepared rehmannia that is the steamed root of rehmannia can be also used as food. This study was performed to analyze the quality properties of the root and the tea with different steaming conditions to evaluate the potential as a tea. Methods and Results : For this study, we used ‘Dagang’, new variety of R. glutinosa, developed by NIHHS. The root was dried and steamed for 9 times. Every steaming, powder and extract were used for pH, antioxidant activity analysis (total phenolic acid and total flavonoid content) and sensory evaluation. As steaming repeated, pH was decreased. The total phenolic acid and total flavonoid content was increased during steaming process. In the sensory evaluation for the tea, 56% of respondents (A group) recognized the difference between 6th and 9th steaming tea correctly but 44% (B group) didn’t. The sensory scores showed that 6th and 7th steaming tea had higher overall preference scores than other samples. This tendency was more clear in the A group. Depending on the age group, there were significant different tendency among 3 age groups (20 – 30 s, 40 – 50 s, over 60 s). The youngest group was preferred 6th than 9th steaming tea. On the other hands, 9th steaming tea had more priority than 6th steaming tea in older age group. Conclusion : This study showed a potential of R. root as a tea material. The quality properties of the R. root are affected by steaming conditions and the preference tendency of tea was different depending on the age group. These data can be used to develop tea material suitable for consumer age and establish optimal steaming conditions in industrial use.
        57.
        2018.10 서비스 종료(열람 제한)
        Background : Rehmannia glutinosa (RG) has been utilized as a traditional medicine in Asia. However, the development of varieties is limited and the climate is changing gradually. Therefore, it is required to develop a superior lineage suitable for this. So we have secured several species, and it is necessary to confirm the cytotoxicity of various kinds of cells for its safety and to secure safety for further utilization. Methods and Results : 11 cultivars and 21 lineages of RG were collected from Rural Development Administration (RDA) at Eumseong of Chungcheongbuk-do and national farmhouse. They were cultivated in test-research farm in RDA and used as materials. Human (THP-1 cell, human leukemia monocytic cell line) and rodent-derived immune cells (RAW264.7, murine monocyte/macrophage cell line) and hepatocytes (HepG2, human liver cell line) were used to assess cytotoxicity. Cytotoxicity was determined by using MTT assay. As a result of evaluation of cytoxicity, 11 cultivars and 21 lineages of RG were not shown cytotoxicity range from 250 - 1,000 ㎍/㎖ concentration in THP-1 cell, RAW264.7 cell and HepG2 cell. Conclusion : Development of RG with superior lineage suitable for changing climate is required. We selected a good lineage (21 ea), and result of the cytotoxicity evaluation from low to high concentrations in immune- and liver-derived cells, there was no toxicity at all. Therefore, if these excellent lineages are distributed to farmers, they can help farmers. And it can help research on immunity and liver function in the future.
        58.
        2018.10 서비스 종료(열람 제한)
        Backgound : Inflammatory bowel diseases (IBDs) are chronic disorders that are characterized by intestinal epithelial inflammation and injury. Currently, the most employed therapies are antibiotics and anti-inflammatory drugs; however, the side effects limit long-term effectiveness. Methods and Results : We evaluated the impact of glucose-lysine Maillard reaction products (Glc-Lys MRPs) on colitis, induced in rats by an administration of 5% dextran sulfate sodium (DSS) in drinking water. Glc-Lys MRPs ameliorate DSS-induced colitis, as determined by a decrease in disease. index activity, colon weight/length ratio, nitric oxide levels in serum, recovery of body weight loss, colon length and serum lysozyme levels. Furthermore, Glc-Lys MRPs increase the glutathione content and the activity of glutathione peroxidase, superoxide dismutase and catalase, and inhibit lipid peroxidation and myeloperoxidase activity in colon tissues. In particular, Glc-Lys MRPs suppress the mRNA level of the inflammatory cytokines and nuclear factor-κB in colon tissues. Conclusion : This study suggests the potential of Glc-Lys MRPs in preventing or treating IBDs.
        59.
        2018.05 서비스 종료(열람 제한)
        Background : Recently there has been an increasing demand for well-being and health food products. Foreign special and medicinal crops which were not cultivated in Korea before are widely introduced and cultivated in Korea. Therefore, in order to provide the basic information necessary for stable cultivation of the introduced crops, we conducted a survey on the actual condition of cultivation of farms and sought to suggest future work. Methods and Results : The survey was conducted in cooperation with the Rural Development Administration and local rural organizations in the year 2015 based on cultivation area, number of farms, and cultivation scale. In thes case of Lepdium meyenii and Asimina triloba, we surveyed the status of management technology by stage of cultivation through the field case study of farms. As a result, 14 crops were cultivated in 1,015 farms in 329.9 ha area including, Allium hookeri, Amaranthus blitum, Annona muricata, Asimina triloba, Chenopodium quinoa, Curcuma longa, Glycyrrhiza uralensis, Gynura procumbens, Lepdium meyenii, Moringa oleifera, Ocimum americanum, Psidium guajava, Silybum marianum, and Stachys japonica. The cultivation scale decreased in the order of C. longa, G. uralensis, A. hookeri, P. guajava, L. meyenii, M. oleifera, and A. triloba. Generally, L. meyenii seeds were sown generally in September and the roots were harvested from mid April to early May in the following year after wintering. A. triloba was cultivated using emerged seedlings or grafted seedlings. The emerged seedlings were more 5 years, and the grafted seedlings were more 4 years so that the fruit can be harvested. Conclusion : In order to stabilize the cultivation of special and medicinal crops introduced from foreign countries, it should be safe and economical in terms of cultivation environment based on domestic cultivation adaptability test, and the use of products and sales channels should be established first. Also, national support and countermeasures for benefit sharing under the Nagoya protocol are needed.
        60.
        2018.05 서비스 종료(열람 제한)
        Background : This study was performed to investigate change in OnjisaponinB contents of Polygala tenuifolia depending on drying methods. Methods and Results : For this study, 5-years-old Polygala tenuifolia local cultivars from RDA(Eumseong) were used. Before starting to drying, root was shade-dried for 3 days and separated with the lead. Next, two types of drying methods conducted; natural drying and hot air drying. Hot air drying was controlled at 40℃, 50℃, 60℃ and 70℃ and checked with every 3 hours. Dried root from market was used as control group. The water content of raw root was about 52.04%. When it started to dry, the contents of it significantly decreased. The dried roots from market were 6.25 - 6.84%. To be under 7% of water contents, 6 hours of drying was enough in natural drying methods and 40℃, 50℃hot air drying methods. In case of 60℃, 70℃ hot air drying methods, it took under 3 hours. The OnjisaponinB contents of raw root was 0.53%. The dried root from market had 0.74% of onjisaponinB. During the drying, the contents of OnjisaponinB changed depending on the drying methods. Hot air drying method had more effect on OnjisaponinB contents than natural drying method. Conclusion : From the above results, we may suggest that natural drying methods was enough to drop the water content of Polygala tenuifolia. Because during pre-treatment steps including shade-drying and separating lead, much of water contents already decreased and became easy to lose water. However to get more OnjisaponinB, hot air drying methods can beneficial than natural drying methods.
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