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        검색결과 521

        223.
        2016.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study proposes a methodology to analyse social networks among participating design engineers during product development projects. The proposed methodology enables product development managers or the participating design engineers to make a proper decision on product development considering the performance of participating design engineers. It considers a product development environment where an integrated product data management (PDM) system manages the product development data and associated product development processes consistently in its database, and all the design engineers share the product development data in the PDM database for their activities in the product development project. It provides a novel approach to build social networks among design engineers from an operational product development data in the PDM database without surveys or monitoring participating engineers. It automatically generates social networks among the design engineers from the product data and relationships specified by the participants during the design activities. It allows analysts to gather operational data for their analysis without additional efforts for understanding complex and unstructured product development processes. This study also provides a set of measures to evaluate the social networks. It will show the role and efficiency of each design engineers in the social network. To show the feasibility of the approach, it suggests an architecture of social network analysis (SNA) system and implemented it with a research-purpose PDM system and R, a statistical software system. A product configuration management process with synthetical example data is applied to the SNA system and it shows that the approach enables analysts to evaluate current position of design engineers in their social networks.
        4,000원
        224.
        2016.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        목 적: 산소투과율이 낮은 콘택트렌즈의 착용은 각막합병증 발생의 원인이 된다. 산소투과율이 높은 실 리콘 하이드로젤 제품의 사용이 각막합병증 예방에 도움 되기 때문에 국내에서도 다수 출시되었지만, 제품 마다 산소투과율이 많이 다른 상황이다. 일부 제품은 산소투과율이 표기되지 않은 상태로 판매되어 그 정보 가 알려져 있지 않다. 식품의약품안전처의 허가정보를 분석하여 국내에서 판매중인 소프트 콘택트렌즈 제품 의 현황을 살펴보고자 한다. 방 법: 식품의약품안전처에서 허가된 소프트 콘택트렌즈 131종을 대상으로 재질은 실리콘 하이드로젤과 하이드로젤이고, 사용목적은 일반 제품과 미용 제품으로 분류하며, 산소투과율은 각막에 필요한 최소 산소 투과율 12, 눈을 뜬 상태에서 각막부종이 생기지 않을 Dk/t 24, 눈을 감은 상태에서 각막부종이 생기지 않 는 Dk/t 87을 기준으로 분류하여 제품의 특성을 분석하였다. 결 과: 국산 하이드로젤 제품은 산소투과율이 Dk/t 12보다 낮은 제품의 비율이 67.2%(41개)이었고, 수입 하이드로젤 제품은 산소투과율 Dk/t 12보다 높은 제품의 비율이 85.7%(12개)였다. 국산 실리콘 하이드로젤 제품은 산소투과율 Dk/t 24보다 낮은 제품의 비율이 73.8%(31개)이었고 성능이 낮은 Dk/t 12보다 낮은 제 품이 52.4%(22개)로 과반을 차지했다. 수입 실리콘 하이드로젤 제품은 산소투과율 Dk/t 24보다 높은 제품 의 비율이 100%(14개)였고, 연속착용이 가능한 Dk/t 87 이상인 제품의 비율이 42.9%(6개)였다. 결 론: 2011년 10.0%였던 실리콘 하이드로젤 처방률이 2015년 24.0%로 증가하였지만, 국내에서 출시된 실리콘 하이드로젤 제품 가운데 일부 제품이 산소투과율이 표기와 다르거나 또는 표기되지 않아 부작용이 발 생할 수 있으므로 제품선택에 주의가 요구된다.
        4,600원
        225.
        2016.06 구독 인증기관 무료, 개인회원 유료
        India is largest producer of banana in the world producing 29.72 million tonnes from an area of 0.803 million ha with a productivity of 35.7 MT ha-1 and accounted for 15.48 and 27.01 per cent of the world’s area and production respectively (www.nhb.gov.in). In India, Tamil Nadu leads other states both in terms of area and production followed by Maharashtra, Gujarat and Andhra Pradesh. In Rayalaseema region of Andhra Pradesh, Kurnool district had special reputation in the cultivation of banana in an area of 5765 hectares with an annual production of 2.01 lakh tonnes in the year 2012-13 and hence, it was purposively chosen for the study. On 23rd November 2003, the Government of Andhra Pradesh has commenced a comprehensive project called ‘Andhra Pradesh Micro Irrigation Project (APMIP)’, first of its kind in the world so as to promote water use efficiency. APMIP is offering 100 per cent of subsidy in case of SC, ST and 90 per cent in case of other categories of farmers up to 5.0 acres of land. In case of acreage between 5-10 acres, 70 per cent subsidy and acreage above 10, 50 per cent of subsidy is given to the farmer beneficiaries. The sampling frame consists of Kurnool district, two mandals, four villages and 180 sample farmers comprising of 60 farmers each from Marginal (<1ha), Small (1-2ha) and Other (>2ha) categories. A well structured pre-tested schedule was employed to collect the requisite information pertaining to the performance of drip irrigation among the sample farmers and Data Envelopment Analysis (DEA) model was employed to analyze the performance of drip irrigation in banana farms. The performance of drip irrigation was assessed based on the parameters like: Land Development Works (LDW), Fertigation costs (FC), Volume of water supplied (VWS), Annual maintenance costs of drip irrigation (AMC), Economic Status of the farmer (ES), Crop Productivity (CP) etc. The first four parameters are considered as inputs and last two as outputs for DEA modelling purposes. The findings revealed that, the number of farms operating at CRS are more in number in other farms (46.66%) followed by marginal (45%) and small farms (28.33%). Similarly, regarding the number of farmers operating at VRS, the other farms are again more in number with 61.66 per cent followed by marginal (53.33%) and small farms (35%). With reference to scale efficiency, marginal farms dominate the scenario with 57 per cent followed by others (55%) and small farms (50%). At pooled level, 26.11 per cent of the farms are being operated at CRS with an average technical efficiency score of 0.6138 i.e., 47 out of 180 farms. Nearly 40 per cent of the farmers at pooled level are being operated at VRS with an average technical efficiency score of 0.7241. As regards to scale efficiency, nearly 52 per cent of the farmers (94 out of 180 farmers) at pooled level, either performed at the optimum scale or were close to the optimum scale (farms having scale efficiency values equal to or more than 0.90). Majority of the farms (39.44%) are operating at IRS and only 29 per cent of the farmers are operating at DRS. This signifies that, more resources should be provided to these farms operating at IRS and the same should be decreased towards the farms operating at DRS. Nearly 32 per cent of the farms are operating at CRS indicating efficient utilization of resources. Log linear regression model was used to analyze the major determinants of input use efficiency in banana farms. The input variables considered under DEA model were again considered as influential factors for the CRS obtained for the three categories of farmers. Volume of water supplied (X1) and fertigation cost (X2) are the major determinants of banana farms across all the farmer categories and even at pooled level. In view of their positive influence on the CRS, it is essential to strengthen modern irrigation infrastructure like drip irrigation and offer more fertilizer subsidies to the farmer to enhance the crop production on cost-effective basis in Kurnool district of Andhra Pradesh, India. This study further suggests that, the present era of Information Technology will help the irrigation management in the context of generating new techniques, extension, adoption and information. It will also guide the farmers in irrigation scheduling and quantifying the irrigation water requirements in accordance with the water availability in a particular season. So, it is high time for the Government of India to pay adequate attention towards the applications of ‘Information and Communication Technology (ICT) and its applications in irrigation water management’ for facilitating the deployment of Decision Supports Systems (DSSs) at various levels of planning and management of water resources in the country.
        4,000원
        226.
        2016.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study of small & Medium-Sized construction sites construction disaster prevention technology conduction-site visits from the map results report by the inspector on-site advice and technical guidance for the analysis of deficiencies and potential construction of disaster revealed the potential factors causing an accident as follows. As a results, Should not be a once a month visits. Therefore should be changed at least twice a month to help prevent accidents of this system is to be judged.
        4,000원
        227.
        2016.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        PURPOSES: This study analyzed the lane-by-lane traffic flow characteristics in Korea by using real-world data, including congestion levels, for 2-, 3-, and 4-lane freeways. METHODS : On the basis of a literature review, lane flow and speed characteristics were analyzed using flow measurements and speed ratios. In addition, the effect of congestion levels on traffic flow were visualized using rescaled cumulative plots. RESULTS: Driver behavior varied depending on the congestion level. During free-flow conditions, the lane-use ratio of individual lanes varied largely, whereas during congestion, the ratio was nearly the same for all lanes (i.e., equilibrium). During maximum-flow and congestion conditions, the median lane was used more than the shoulder lane, whereas during all other conditions, the shoulder lane had a higher lane-use ratio. In 3- or 4-lane freeways, the lane-use ratio of the median lane always exceeded 1 and was the highest during free-flow conditions. CONCLUSIONS : The results of the present analysis can be used as an index to predict congestion before a lane is overcapacitated. Moreover, the results can be applied in variable lane guidance systems, such as car navigation systems and variable message displays, to control traffic flow.
        4,000원
        229.
        2016.04 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Although the Hazen-Williams C factors are very important in the design, operation, and maintenance of water supply pipes, sufficient studies for them have been not reported in korea, which are based on experiments or measured data. Because of this, we have estimated C factors by measurement considering constraints in time precise safety diagnosis for multi-regional water supply system were performed. In this study, we confirmed constraints and variables characteristics of Hazen-Williams equation, and collected reliable C factors data of 174 by measurement, and analyzed their characteristics. According to collected data, the average value is 115.35, which is almost equal to the value of design standard or a little higher than it in korea. Also, among the equations suggested to determine C factor in the past, the C factors calculated by Sharp and Walski equation was closest to them in this study. In addition, to analyze collected C factors, use year and pipe diameter having high correlation with them were respectively divided into there categories. Analysis results showed that C factors evidently decreases depending on increases in use year, on the other hand, size of pipe diameter is proportional to value of them. In conclusion, this research showing evaluation and characteristics for C factors based on measured data will be used as practical reference in determining C factor in multi-regional water supply systems at a later date.
        4,000원
        230.
        2015.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        이 논문에서는 고속철도교량 설계를 위한 활하중 모델을 통계 및 확률적 방법으로 검토하고, 하중조합의 하중계수가 주는 안전율을 분석하였다. 이 연구는 철도교량 설계기준에 대한 한계상태설계법 개발의 일환이며, 이를 위하여 경부고속철도를 운행하는 열차를 대상으로 약 한달 동안 실측하여 데이터를 수집하고 분석하였다. 이 데이터를 대상으로 교량의 설계수명에 맞도록 4가지 통계 방법들을 적용하여 설계하중을 추정하여 비교․검토하였다. 또한, 철도교량의 설계하중조합이 주는 안전율을 검토하기 위하여 신뢰도지수를 구하고 이를 분석하였다. 실측 데이터로부터 추정한 활하중효과에 대하여, 현행 고속철도 설계활하중인 표준열차하중의 0.75배를 적용한 설계활하중 효과의 크기가 최소 30~22% 더 크게 나왔다. 신뢰도분석을 통하여, 극한한계상태만을 기준으로 본다면, 추가적인 하중계수 감소의 가능성이 있음을 알 수 있다.
        4,000원
        231.
        2015.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The effect of weir construction (2009~2011) was investigated on algal bloom dynamics and surrounding conditions in the Youngsan River by analyzing the long-term (2001~2014) data provided by the Water Information System, Ministry of Environment. The data include chlorophyll a and water properties such as total suspended solids (TSS), ammonium (NH4 +), nitrate (NO3-), orthophosphate (PO43-), total nitrogen (TN), total phosphorus (TP) and DIN/DIP molar ratio collected from 12 stations along the channel of the river. Temporal variations were examined using data collected monthly from 2001~2014 and Box-Whisker plot was used to examine the difference in algal bloom dynamics between before (2006~2008) and after (2012~2014) the weir construction. Pearson’s correlation analysis was also used to analyze the correlation of parameters. The results showed that TSS affecting water turbidity increased during the construction but decreased especially at the stations located in the upper and middle regions of the river after the construction. Ammonium concentrations increased whereas the concentrations of other nutrients decreased after the construction inducing an increase in N:P molar ratio. Chlorophyll a decreased suddenly during the construction but increased clearly after the construction at the stations where TSS decreased. This indicates that algal blooms can develop in the Youngsan River due to a decrease in turbidity that increases light penetration in water column although the concentrations of nutrients such as orthophosphate were reduced after the weir construction.
        4,800원
        232.
        2015.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Conventional data envelopment analysis (DEA) models require that inputs and outputs are given as crisp values. Very often, however, some of inputs and outputs are given as imprecise data where they are only known to lie within bounded intervals. While a typical approach to addressing this situation for optimization models such as DEA is to conduct sensitivity analysis, it provides only a limited ex-post measure against the data imprecision. Robust optimization provides a more effective ex-ante measure where the data imprecision is directly incorporated into the model. This study aims to apply robust optimization approach to DEA models with imprecise data. Based upon a recently developed robust optimization framework which allows a flexible adjustment of the level of conservatism, we propose two robust optimization DEA model formulations with imprecise data; multiplier and envelopment models. We demonstrate that the two models consider different risks regarding imprecise efficiency scores, and that the existing DEA models with imprecise data are special cases of the proposed models. We show that the robust optimization for the multiplier DEA model considers the risk that estimated efficiency scores exceed true values, while the one for the envelopment DEA model deals with the risk that estimated efficiency scores fall short of true values. We also show that efficiency scores stratified in terms of probabilistic bounds of constraint violations can be obtained from the proposed models. We finally illustrate the proposed approach using a sample data set and show how the results can be used for ranking DMUs.
        4,800원
        233.
        2015.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구는 지하철 입구 공공공간에서 피험자의 선택적 주의집중 분석을 위한 공간요소별 주시데이터 추출이다. 주시데이터의 추출방법 연구 결과는 다음과 같다. 첫째, 눈을 통해 획득되는 시각정보의 특성을 분석하는 과정에 중심와의 반경을 이용하여 주시범위를 설정하는 방식은 기존의 시지각 이론을 근간에 두면서 선택적 주의집중에 해 당하는 주시데이터의 추출 결과를 객관화시킬 수 있는 방법을 정리했다. 둘째, 주시데이터 추출방법으로 기존에는 격자에 의한 빈도 분석이 주를 이루었는데 세부적 특성으로 공간정보를 분석함에 한계를 가지고 있었다. 이에 비해 선택적 주의집중 정도를 알 수 있는 주시데이터 추출방법은 공간에서 특정 요소에 시선이 얼마만큼 집중되는지를 분석해 낼 수 있었다. 선택적 주의집중을 통해 공간사용자의 주시특성을 분석하게 되면, 요소 맞춤형 주시데이터 추출이 가능하고, 이를 공간디자인이나 사인 배치에 활용하고 성과를 검증하는 것도 가능하다. 셋째, 공간요소에 대 한 시간범위별 분석을 통해 특정 공간 요소를 주시한 데이터 특성을 시계열적으로 추적하여 정리하는 것이 가능했는 데, 본 연구에서 대상으로 삼은 「해당 공간범위」의 결과를 보면, 남녀 모두 2분을 지난 시점에서 주의집중 정도가 급격히 떨어진 것을 확인할 수 있었다. 넷째, 주시 우위빈도를 통해 선택적 주의집중이 일어난 구역을 시간범위별로 분석하였는데, 성별에 따라 남자는 Ⅰ시간범위(52.4 %), 여자는 Ⅳ시간범위(24.0 %)에서 강한 주시가 이루어진 특 성이 있어, 성별 차이가 나타난 것을 확인할 수 있었다. 즉, 성별에 따라 선택적 주의집중이 일어나는 시간범위가 서로 다르다는 것에서부터 성별 차이를 향후 피험자 특성으로 설정하여 실험하고 분석하는 것이 필요하다.
        4,300원
        236.
        2015.10 구독 인증기관 무료, 개인회원 유료
        Recently, transaction data is accumulated everywhere such as bank and IT company. Association analysis methods are usually applied to analyze transaction data, but the methods have several problems. For example, these methods only consider one-way relations among items and cannot reflect domain knowledge to analysis process. In order to overcome defect of association analysis methods, we suggest a transaction data analysis method based on probabilistic graphical model (PGM) in this study. The method we suggest has several advantages as compared with association analysis methods. For example, this method has a high flexibility, so it can give a solution to various probability problems regarding the transaction data and can consider various relationships among items.
        4,000원
        238.
        2015.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구는 경상북도 구미시 천생산 지역에서 발달하는 타포니를 대상으로 암석의 풍화 과정 및 타포니의 형성 과 정을 분석하고 있다. 연구지역의 타포니 발달은 조립질 퇴적암인 역암과 역질사암에서 발생빈도가 높으며 타포니의 발생 은 역의 이탈 및 박리가 발생한 지점에서부터 시작되는 것으로 추정된다. 지형적으로 산지의 남사면 암석 노출지에서 타 포니의 집중적 발달이 관찰되는데, 이는 겨울철 기계적 풍화와 여름철 화학적 풍화의 진행이 상대적으로 높은 환경적 조 건에 따른 것으로 해석된다. 타포니가 발달한 암석 표면에서 측정한 함수율의 분포 특성은 타포니 발생 지점이 주변에 비해 높은 함수율을 명확히 보여주고 있어 암석 내의 수분은 어떤 기제로든 타포니 발생에 상당한 영향을 끼치는 것으로 판단된다. 타포니 내에서 확인되는 풍화 침전물 및 이차광물에 관한 분석은 후속 연구로 현재 진행 중에 있다.
        4,000원
        240.
        2015.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The purpose of this research was to investigate the relationship between white rice consumption and dietary intake, the risk of metabolic syndrome in Korean based on 1st (1998), 4th (2007~2009), 6th (2013) KNHANES. This study included 25,799 subjects who were age 10 or over. Three groups(low, medium, high) were divided according to white rice consumption (per day). In the low group, the meat and oil intake were significantly higher than the high group. In the 1st survey year, the BMI, waist circumstances, hypertriglyceridemia and fasting blood glucose in the high group were higher than other groups, however the 4th and 6th survey year showed no significant results. In the 1st survey year the risk of waist circumstances was higher in the high white rice consumption group and also had high risk with hypertriglyceridemia. Since the lower white rice consumption in 4th than 1st survey year we found no significant results. But in the 6th survey year with the lowest white rice consumption the risk of high diastolic pressure was reduced in high group. Because continuously reduced white rice consumption meantime showed more intake of meat and oil, it can be concluded that defensive effects with the Korean health.
        4,500원