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        검색결과 18

        1.
        2023.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In recent years, the government has strongly promoted multi-purpose utilization of paddy field. However, poor drainage causes waterlogging stress in upland crops, requiring subsurface drainage technology, resulting in high installation and management costs. To address this issue, a low-cost and high-efficiency technique was developed that utilizes wasted coir substrates which have characteristics of high porosity and good drainage, for upland crop cultivation in paddy fields. Soybeans were grown in both paddy soil and wasted coir slab with two planting densities (80×20 cm and 60×20 cm). The results showed that the coir substrates had better performance than the paddy soil in terms of soil physical and chemical properties and the growth and yield of upland crops are improved. The treatments using wasted coir substrate showed a 41.4% increase in yield and a 21.3% increase in protein content compared to PS treatment. Our findings demonstrate that recycling waste coir substrates to grow upland crops is a positive cultivation strategy to solve some drainage problems in paddy fields. This approach offers a sustainable solution for upland crop production while also addressing the issue of waste management in agriculture.
        4,000원
        2.
        2022.04 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The purpose of this paper is to propose part management and standardization to reduce cost and increase compatibility of parts through standardization and standardization of parts to be applied to urban air mobility(UAM) systems, Personnel Air Vehicle(PAV), Vertical Take-Off and Landing (VTOL), and so on. In other words, parts used in the urban air transportation system must be verified from the initial design stage in accordance with the aviation standard, and a systematic management system for various parts must be established to secure stability and improve quality. Therefore, as a system similar to the aviation component management system, it should be thoroughly managed for urban aviation components.
        4,000원
        3.
        2014.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The aim of present study was to improve the quality of silage using lactic acid bacteria (LAB) and chlorella as a supplement. Italian ryegrass (IRG) mediated silage was prepared with lactic acid bacteria (L. plantarum) and different concentration of chlorella. We analyzed the nutritional profiles such as crude protein (CP), acid detergent fiber (ADF) neutral detergent fiber (NDF), total digestible nutrient (TDN) and in-vitro dry matter digestibility (IVDMD), microbial counts and fermentative acids such as lactic acid, acetic acid and butyric acid in the control and experimental silage after three months. It shows increased crude protein content and also maintains the rest of nutritional values as compared with control silage. LAB inoculation with chlorella as supplementation slightly reduced the pH of the silage. In addition, it increased the fermentative acids production as compared with control silage and inhibits the undesired microbial growth especially fungi in the silage. Therefore, we suggest that LAB inoculation and chlorella supplementation to the IRG mediated silage could be improved the nutritional quality of the silage which is an intrinsic feature for the application in the preparation of animal feeds and functional foods.
        4,000원
        4.
        2014.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        A prerequisite for improving the quality of a product is to enhance the quality of its parts supplied from outsourced enterprises. An enterprise certified by ISO 9001 Quality Management System is expected to develop their effective quality assurance system and maintain it through continuous control and improvement, thereby ensuring the good quality of products that they produce. However, it is reported that small and medium–sized enterprises certified by ISO 9001 have difficulty establishing an effective quality assurance system. This study aims to propose a new method of improving a quality assurance system that can be more effective in small and medium–sized enterprises. This study collectively considered requirements specified in several international standards on quality system and the results of expert group brainstorming to identify evaluation areas and items for assessing a quality assurance system. Based on these evaluation areas and items, a set of checklists for diagnosing and improving a quality assurance system was developed. In order to demonstrate the usefulness of the proposed method, this study applied it to ten small and medium-sized enterprises and could identify four approaches for improving their current quality assurance system. The presented improvement method, which consists of establishment of quality goals and quality innovation plan, defective products corrective activities, 4M and design change process, improvement of customer quality information management, is expected to be utilized as a useful tool for the enhancement of the quality assurance system of small and medium-sized enterprises.
        4,300원
        5.
        2008.05 구독 인증기관 무료, 개인회원 유료
        가변단면 압출기술은 사용하는 금형의 조합에 의해 다양한 가공이 가능한 성형공법으로, 압출시에 금형의 움직임에 의하여 제품의 단면형상을 변화시키거나, 치수와 두께를 동시에 변화시킬 수 있다. 압출공정에서 압출속도, 압출압력, 압출온도는 압출품의 표면결함이나 내부품질에 있어 중요한 영향인자이다. 그중 일정한 압출속도는 균일한 메탈 플로를 형성하여 성형품질에 있어서 고른 상태를 유지하게 만드는 요소이다. 기존의 압출 성형에서 펌프토출양의 변화에 의한 추출속도변동 문제는 램 속도의 변화를 계측하고 토출 양을 조정함으로써 압출속도를 제어하는 방법으로 해결한다. 그러나 가변단면 압출공정에서는 제품의 단면형상의 변화에 따라 압출비가 변하므로 이에 따른 램 속도 제어가 있어야만 한다. 본 연구에서는 가변단면 압출공정에서 가공형상에 따른 제어 알고리즘을 제시하여 가변 형상에 따른 램의 이동 속도 및 위치를 제공하려 한다.
        4,000원
        6.
        2007.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
          절삭가공에서 가공조건은 가공비용의 감소와 제품 품질의 향상에 영향을 주는 주요 요인 중의 하나이다. 본 논문에서는 밀링작업을 대상으로 가공조건을 보다 효율적으로 수정하고 이를 지속적으로 향상시킬 수 있는 방법론과 이를 기반으로 개발된 작업설계시스템을 소개한다. 개발된 시스템은 (1) 표준 가공조건을 세부 공정별 요구 사항이 만족되도록 수정하고, (2) 퍼지아트맵 신경회로망 모델을 이용하여, 생성된 가공조건을 온라인(incremental) 학습한 후,
        4,000원
        7.
        2005.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구에서는 한국 지구과학 올림피아드 문항의 질 향상 방안을 모색하고자 1회와 2회 예선 및 본선 문항을 다양한 측면에서 분석하였다. 문항 분석을 위해 내적 및 외적 문항 분류틀을 구안하여 적용하였다. 고전 검사이론을 적용하여 문항의 난이도와 변별도, 상관계수, 그리고 신뢰도를, 일반화가능도 이론을 적용하여 일반화가능 도를 각각 추정하였다. 문항 분류틀 적용 결과는 다음과 같다: (1) 내용 차원에서는 지질 영역과 천문 영역에, 지식 및 탐구과정 차원에서는 자료 분석 및 해석에 집중되는 경향을 보였다. 또한 맥락 차원에서는 거의 대부분의 문항이 교과서적인 상황을 토대로 한 것이었다. (2) 요구 사고 수준에서 예선과 본선간의 차이를 발견할 수 없었다. (3) 문항 표현 범주에서는 그림의 사용 비율이 가장 높았고, 문항 유형 범주에서는 예선은 선다형과 단답형의 비율이, 본선은 서술형의 비율이 높았다. 또한 문항 형식 범주에서는 중학부와 예선은 단독형의 비율이 높고, 고교부와 본선은 복합형의 비율이 높았다. 문항을 분석한 결과는 다음과 같다: (1) 중학부는 대체로 난이도가 낮고, 변별도는 적절하였다. 그러나 고교부는 일반고와 과학고간에 상당한 차이가 있었다. (2) 중학부는 대기 영역과 총점과의 상관이, 고교부는 천문 영역과 총점과의 상관이 가장 높았다. (3) 양호한 문항이 가장 많은 일반고부의 문항 내적 일관성신뢰도와 일반화가능도가 가장 높았다. (4) 일반 고는 출제된 문항 수로 적정 수준의 일반화가능 도에 도달되나, 중학부나 과학고는 출제된 문항보다 2배 이상 많은 문항수가 필요한 것으로 나타났다.
        4,500원
        8.
        2018.04 KCI 등재 서비스 종료(열람 제한)
        본 연구는 Image J 프로그램을 사용하여 유속증가 자기공명영상기법의 숙임각 변화에 따른 SNR와 CNR을 측정하여 최적의 숙임각을 알아보기 위해 연구하였다. 총 30명의 정상인 지원자를 대상으로 1.5T 자기공명영상기기(Philips, Medical System, Achieva)를 이용하여 뇌동맥검사 후 평가를 실시하였다. 분석 방법으로 유속증가 자기공명 혈관 조영술에 대하여 4 부위에 관심영역을 설정하고 SNR와 CNR을 평가하였다. 5가지 숙임각에서의 정량적 분석으로 SNR과 CNR에 대한 통계적 유의성은 일원분산분석으로 계산되었으며, 사후 분석으로는 Bonferroni 법을 적용하였고, 통계에 사용된 프로그램은 SPSS 14.0을 이용하여 p 값을 0.05 이하일 때 유의성을 두었다. 본 실험에 대한 결과로서 전교통동맥(SNR:876.59 ± 14.22, CNR:1999.7 ± 12.5), 후교통동맥 (SNR: 863.48 ± 13.29, CNR:1870.18 ± 12.56), ICA(SNR: 1116.87 ± 08.34, CNR:2979.37 ± 14.69), 중대뇌동맥(SNR:848.66 ± 15.25, CNR:2199.25 ± 13.48)의 값으로 25°에서 가장 높은 신호강도를 보였다(p<0.05). 작은 혈관 묘출로서 a1, a2, a3, p1, p2, p3, m1, m2, m3 값 또한 동일한 결과 이었다(p<0.05). 사후분석결과로, 숙임각에서 25° 기준으로 10°, 15°, 20°에서 유의성 있는 결과를 얻었지만(p=0.000) 30° 에서는 유의한 차이가 없었다(p>0.05). 결론적으로, 본 연구에서 30° 에서는 신호강도가 떨어지기 때문에 뇌혈관 자기공명조영술에서 최적의 숙임각은 25°로 나타냈다.
        9.
        2017.09 서비스 종료(열람 제한)
        It has been many studies and technical developments of recycled aggregate for concrete, but some limits due to lacks of quality control and reliability. Thus, this study addresses to find real problems in using recycled aggregate for concrete through questionnaire. It is known that first of all, proper grades of commercially available recycled aggregate shall be necessary to produce proper and economical concrete.
        10.
        2016.10 KCI 등재 서비스 종료(열람 제한)
        방사선 검사로 환자의 병을 진단하기 위해서는 방사선 피폭이 따르게 된다. 최소한의 피폭으로 병변을 진단하는 일반촬영에 이중 엑스선 에너지 기법의 임상적용 가능성을 SNR 및 화질 점수화의 지표로 조사하였다. 이중 엑스선 에너지 기법은 검출기로 사용되는 두 개의 Image Plate 사이에 0.5 mm 두께의 Cu와 Al 필터를 추가함으로써 구현하였다. 한 번의 엑스선 조사로 획득된 두 IP 영상을 Subtraction 및 Enhance Contr ast 기법을 적용하여 획득하였다. Enhance 영상은 첫 번째 IP에서 획득한 First 영상보다 SNR이 우수한 것으로 측정되었다. 이 일반촬영의 이중 엑스선 에너지 기법은 피폭선량을 줄이면서 영상의 품질을 높일 수 있는 방법으로 임상에서 매우 유용하게 적용될 수 있을 것이다.
        11.
        2014.06 KCI 등재 서비스 종료(열람 제한)
        This study was performed to enhance contents of low molecular ginsenoside using steaming and fermentationprocess in low quality fresh ginseng. For increase in contents of Rg2, Rg3, Rh2 and CK in low quality fresh ginseng, a steam-ing process was applied at 90℃ for 12hr which was followed by fermentation process at Lactobacillus rhamnosus HK-9incubated at 36℃ for 72h. The contents of ginsenoside Rg1, Rb1, Rc, Re and Rd were decreased with the steaming associ-ated with fermentation process but ginsenoside Rg2, Rg3, Rh2 and CK increased after process. It was found that under thesteaming associated with fermentation process, low molecule ginsenosides such as Rg2, Rg3, Rh2 and CK were increased as3.231㎎/g, 2.585㎎/g and 1.955m/g and 2.478㎎/g, respectively. In addition, concentration of benzo[α]pyrene in extracts ofthe low quality fresh ginseng treated by the complex process was 0.11ppm but it was 0.22ppm when it was treated with thesteaming process. This result could be caused by that the most efficiently breakdown of 1,2-glucoside and 1,4-glucoside link-age to backbone of ginsenosides by steaming associated with fermentation process. This results indicate that steaming pro-cess and fermenration process can increase in contents of Rg2, Rg3, Rh2 and CK in low quality fresh ginseng.
        12.
        2012.06 KCI 등재 서비스 종료(열람 제한)
        최근 국제해사기구에서 추진하고 있는 e-navigation은 선박의 안전운항을 위한 다양한 서비스를 지향하고 있다. 이에 따라, 해양 분야에 다양한 소프트웨어 개발이 기대되고 있으며, 동시에 그 품질의 중요성이 높아지고 있다. 이 논문에서는 소프트웨어의 품질 향상의 실험을 위해, 기존 AIS중개서버 프로그램에 소프트웨어 리팩토링(refactoring) 기법을 적용하였으며, 그 효과를 분석하였다. 리팩토링은 소프트웨어를 소스 코드 수준에서 구조의 복잡성을 줄여서, 이해하기 쉽고 기능 변경이 용이한 상태로 변경하는 기법이다. 이를 통해, 겉으로 보이는 동작의 변화는 없이 내부구조가 변경된다. 리팩토링 적용 효과 분석을 위해서, IEC/ISO 9126 소프트웨어 품질표준의 유지보수성과 관련된 기존 메트릭의 산술적 측정기법을 도입했다.
        13.
        2012.04 KCI 등재 서비스 종료(열람 제한)
        This study compared the contents of low molecular ginsenoside according to fermentation process in low grade fresh ginseng. Low grade fresh ginseng was directly inoculated with a 24 h seed culture of Bifidobacterium Longum B6., Lactobacillus casei., and incubated at 36℃ for 72 h. Bifidobacterium Longum B6 was specifically was found to show the best growth on 3,255×106 CFU/ml after 48 h of fermentation. The content of ginsenoside Rb1, Re and Rd were decreased with the fermentation but ginsenoside Rh2 and Rg2 increased after fermentation process. In the case of low molecular ginsenoside conversion yields were 56.07% of Rh2, 12.03% of Rg3 and 77.11% of Rg2, respectively. In addition, compound-K was irregular conversion yield as long as 72 h of fermentation. This results indicate that fermentation process could increase the low molecular ginsenoside in low grade fresh ginseng.
        14.
        2010.06 KCI 등재 서비스 종료(열람 제한)
        Low quality fresh ginseng was fermented by Pheliuus linteus mycelium at 22℃ for 30 days, then extracted by water solvent at 100℃ for 180 min. On human normal cell lines (HEK293), cytotoxicity was about 10% lower in adding extracts of the fermentation ginseng than that from low quality ginseng. The fermented extracts also inhibited the growth of several human cancer cells. Among them, respectively, digestive organs related cancer cells, such as human stomach adenocarcnioma and human epithelial adenocarcinoma were most effectively inhibited up to 85% and 90%, respectively. Then, selectivities were in the ranges of 3 to 5, compared to 2 to 3 from low quality fresh ginseng. Generally, fermented ginseng extract showed higher anticancer activities as well as higher DPPH radical sacavening activity, possibly due to high contents of total phenolic components as 6.96 mg/g. It was very interesting that the fermented ginseng contained very higher contents of ginsenoside-Rc+Rb2, compared to others in low quality fresh ginseng because of partition digestion of mycelium growth. The results can tell that low quality fresh ginseng can be utilized by the fermentation with Pheliuus linteus mycelium.
        15.
        2009.09 KCI 등재 서비스 종료(열람 제한)
        An objective of this study is as follows: 1) performing sensitivity analysis and parameter estimation of RMA2 and RMA4 models for the West-Nakdong River, 2) drawing up alternatives of gates-operation for water-quality enhancement, and 3) quantitative evaluation of methodology of 'flow-restoration by gates-operation' among 'Comprehensive Plan Improving Water-Quality in the West-Nakdong River(WNR)' with the target water-quality(BOD at Nakbon-N point: below 4.3 mg/L). The parameters for the RMA2 (depth-averaged two-dimensional flow model) and RMA4 (depth-averaged two-dimensional water-quality model) were determined by sensitivity analysis. Result of parameter estimation for RMA2 and RMA4 models is 1,000 Pa․s of the eddy viscosity, 20 of the Peclet number, 0.025 of the Manning coefficient, and 1.0 m2/s of the diffusion coefficient. We have evaluated the effects of water-quality enhancement of the selected alternatives by numerical simulation technique with the models under the steady-state flow condition and the time-variant transport condition. Because of no-resuspension from river bottom and considering BOD as conservative matter, these simulation results slightly differ from real phenomena. In the case of 50 m3/s of Daejeo-gate inflow, two-dimensional flow pn results result represents that small velocity occurs in the Pyungkang Stream and no flow in the Maekdo River. In the WNR, there occurs the most rapid flow near timhae-bridge. In the WNR, changes of water-quality for the four selected simulation cases(6, 10, 30, 50 m3/s of the Daejeo-gate inflow) were predicted. Since the Daejeo-Gate and the Noksan-Gate can be opened up to 7 days, it would be found that sustainable inflow of 30 m3/s at the Daejeo-gate makes BOD in the WNR to be under the target of water-quality.
        16.
        2007.06 KCI 등재 서비스 종료(열람 제한)
        This study aims to develop a rational evaluation system which consists of the selection of evaluation items and the estimation of its weight for the Enhancement Program of the Quality of Life for Farmers and Fishermen and Rural Development. This system has two hierarchical steps. The first step shows the evaluation goals which are relevance, efficiency and effectiveness of the program. The second step stands for the evaluation items which have 11 sub-items such as necessity and externalization for the program, rationality of procedures, feedback and monitoring system, budgetary allocations, information activities, impacts on the program, achievements of the goals and so on. A tentative evaluation system was proposed by brainstorming and Delphi method of expert-group. Weighting values of evaluation items were calculated through pair-comparison works of expert group using stepwise matrix sheets by AHP(Analytic Hierarchy Process).
        17.
        2003.03 KCI 등재 서비스 종료(열람 제한)
        Seeds of burcucumber were treated with accelerated aging, cold-stratification, and light quality illuminated during desiccation to enhance their germination and seedling emergence. The germination was increased by aging and cold-stratification although the latter treatment showed greater effectiveness than the former one. In the combined treatment of aging 6 days at 45~circC and cold-stratification, the germination was promoted under longer period of cold-stratification to reach nearly 100% in 3 week cold-stratification on the ninth day from sowing. In the sequentially combined treatment of aging, cold-stratification, and light quality during 24 hour desiccation at 35~circC , no-stratified seeds showed the highest rate in red light treatment but the lowest in far-red light. This implies that the phytochrome action run during the desiccation of imbibed seeds. The red light exposure during drying for the cold-stratified seeds after aging accelerated the germination even more than the dark treatment and germinated 100% on the next day of sowing. It is concluded that the sequential treatment of aging, cold-stratification, and red light illumination during desiccation can highly promote percentage and speed of burcucumber seed germination.
        18.
        1998.06 KCI 등재 SCOPUS 서비스 종료(열람 제한)
        For the purpose of enhanceing soybean-sprouts quality, the optimum conditions for ozone treatment of soybean during soaking before cultivation at 18~2 were evaluated with ozone concentration, treatment time and treatment frequency by response surface methodology. Germination rates of cleaned soybean by ozone water in the conditions of solubilized-ozone concentrations of 0.15 to 0.35ppm, ozone-treatment frequency of 1.5 to 2.3 times and ozone-treatment time of 30 to 36min. increased 18.8 to 24.0% for the control products. And, length of hypocotyl in conditions of 0.12 to 0.33ppm, 1.7 to 2.7 times and 45 to 90min. were also increased by 69.36 to 79.40%. On the other hand, weight of roots with ozone treatment were decreased in the conditions of solubilized ozone concentrations of 0.1 to 0.2ppm and ozone-treatment time of 30 to 57min. But, ozone-treatment frequency did not affected root growth. Putrefaction rates of the control were 5 to 15%, but those of ozone-treated samples during cultivation did not show. The overall optimum conditions for above 16% germination rates, above 9% hypocotyl yields compared to the control samples and below 98% of the control root weight were solubilized-ozone concentrations of 0.25 to 0.30ppm, ozone-treatment time of 43 to 49min. and ozone-treatment frequency of one time.