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        검색결과 24

        1.
        2024.04 구독 인증기관·개인회원 무료
        탄소섬유 강화 플라스틱 (Carbon fiber reinforced plastics, CFRP)은 고함량의 탄소섬유 (Carbon fiber, CF)와 고분자로 이루어진 복합재료로서, 뛰어난 기계적 성능으로 항공우주, 자동차, 토목 등 다 양한 산업 분야에서 사용되고 있다. 하지만 사용량 증가에 따른 폐기물의 환경문제와 추출한 재활용 탄소섬유 (Recycled carbon fiber, rCF)의 적용 가능 분야의 한계로 인해 재활용이 제한적인 실정이 다. 본 연구에서는 rCF와 CF 혼입 시멘트계 전자파 복합재를 제작하여 그 성능을 비교 분석하기 위 한 실험을 수행하였다. 구성재료는 시멘트, 잔골재, 고성능 감수제를 사용하였으며, 비교 분석을 위해 CF와 rCF를 각각 6 mm, 12 mm 길이를 0.1, 0.3, 0.5, 1.0 wt.% 함량으로 사용하였다. 전자파 복합 재의 흡수 성능 향상을 위해 각각 다른 함량의 다층 구조를 형성하였으며, 전자파 투과를 낮은 함량에 서 높은 함량 방향이 되도록 측정을 진행하였다. 전자파 차폐성능은 재령 28일 이후 네트워크 분석기 를 사용하여 자유 공간에서 측정하였으며, C-band (4~8 GHz)와 X-band (8~12 GHz) 주파수 영역 에서의 반사율과 투과율을 각각 측정하였다.
        2.
        2024.04 구독 인증기관·개인회원 무료
        본 연구는 탄소 기반 필러인 탄소나노튜브 (Carbon nanotube, CNT), 탄소 섬유 (Carbon fiber, CF) 와 중공유리구체 (Hollow glass microsphere, HGM)를 혼입한 전도성 복합재료가 다양한 열화 상황 에 노출된 이후의 발열성능을 조사하고 분석하였다. 대부분 상황에서 시멘트 기반의 재료들은 질산 및 황산의 침투 또는 동결융해와 같은 다양한 자연적 열화상황에 노출되게 된다. 본 연구는 기존의 이러 한 한계를 극복하고자 HGM, 전도성 필러를 혼입한 전도성 복합재료를 제조하였고, 물리적·전기적 및 열적 특성을 조사하였다. 모든 시편에서 HGM의 혼입은 시편의 밀도와 열 전도도를 감소시켰으며, 다 량의 혼입은 강도와 전기 전도도를 감소시키는 결과를 관찰할 수 있었다. 그러나 적정량의 혼입은 오 히려 전기 전도도를 향상시키는 결과를 확인할 수 있었으며, 반복적인 발열 실험에서의 성능 유지 또 한 미혼입 시편에 비하여 상대적으로 뛰어난 것을 관찰할 수 있었다. 이러한 HGM의 혼입에 대한 영 향을 더욱 자세하게 분석하기 위하여 수은압입법, 주사전자현미경, 제타전위 및 라만분광법 등의 분석 이 수행되었다.
        3.
        2024.04 구독 인증기관·개인회원 무료
        This research investigates the incorporation of eco-friendly materials, namely fly ash and artificial interior stone sludge into cement grouts. The study aims to establish the correlation between the microstructural properties and the compressive strength, providing a comprehensive behavior of fly ash and artificial interior stone (AIS) sludge on the cement grouts. A multifaceted experimental approach encompassing compressive strength testing, mercury intrusion porosimetry, thermogravimetric analysis, and scanning electron microscopy is employed. The result indicated that incorporating fly ash and artificial interior stone sludge into cement grouts led to a reduction in the porosity and refinement of the pore size. The thermogravimetry analysis revealed a notable impact of fly ash and artificial interior stone sludge on hydration and phase transition. The scanning electron microscopy findings of the microstructural enhancement confirmed that the combined incorporation of fly ash and AIS sludge densified the structure.
        4.
        2023.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study addresses the optimal design methodology for switching between active electronically scanned array (AESA) radar operating modes to easily select the necessary information to reduce pilots' cognitive load and physical workload in situations where diverse and complex information is continuously provided. This study presents a procedure for defining a hidden Markov chain model (HMM) for modeling operating mode changes based on time series data on the operating modes of the AESA radar used by pilots while performing mission scenarios with inherent uncertainty. Furthermore, based on a transition probability matrix (TPM) of the HMM, this study presents a mathematical programming model for proposing the optimal structural design of AESA radar operating modes considering the manipulation method of a hands on throttle-and-stick (HOTAS). Fighter pilots select and activate the menu key for an AESA radar operation mode by manipulating the HOTAS’s rotary and toggle controllers. Therefore, this study presents an optimization problem to propose the optimal structural design of the menu keys so that the pilot can easily change the menu keys to suit the operational environment. K
        4,500원
        7.
        2013.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구에서는 정밀농업 구현을 위해 필수적인 요소인 토양과 기후 그리고 위치요인을 데이터로 구축한 후 이를 수치화하여 최고점수제를 이용하는 지식기반형 작물추천모델을 개발하였다. 작물추천시스템에서 사용한 요인은 토양과 기후 그리고 위치정보이다. 토양의 경우에는 흙토람 자료 중 작물적지 선정에 80%이상 활용되는 토성, 침식등급, 배수등급, 경사, 자갈함량, pH를 선정하였다. 기후요인은 기상청의 5년간 누적데이터를 기초로 하여 작물생육에 필수적인 기온과 강수량 그리고일조시간 등을 사용하였다. 위치정보는 한국토지정보시스템과 수치지형도를 가공하여 사용하였다. 예시작물은 농촌진흥청에서 추천한 옥수수, 유채, 갈대, 수박, 고추, 토마토, 양파, 감자, 고구마, 구기자 10개 작물로 하였으며, 향후 작물추천 수요가증가할 것으로 예상되는 제천, 무안, 원주, 함안 4개 지역을 포괄적으로 시뮬레이션하였다. 분석결과 평균점수는 고추가 75.5점으로 가장 높았으며 고구마가 61.2점으로 가장 낮았다. 작물별 식재면적에 제약이 있다고 가정하고 2차 시뮬레이션을실시하여 경남 함안시의 7만 필지를 별도설정하고 분석한 결과 고구마가 39,190필지에서 가장 높은 점수를 받았으며 면적으로는 27.014 km2이었다. 지식기반형 작물추천시스템은 작물의 적지를 선정하는 항목과 가중치가 검증되지 않았다는 한계를 가지고 있으나, 이에 대한 보완이 이루어지고, 농산물유통부분을 고려하여 실제 정보수요자에게 제공하면 영농현장에서 활용 가능할 것으로 판단한다.
        4,000원
        8.
        2010.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Since there had been the first human outbreak of novel influenza A/H1N1 in Mexico, it has become pandemic throughout the world. In the Republic of Korea, the first human case was on May, 2009 and National Veterinary Research and Quarantine Service (NVRQS) has started monitoring novel influenza A/H1N1 on domestic swine farms. The first positive case was detected on 14, Dec, 2009 and until now, we have had total 17 positive cases. From the first case, we did epidemiological investigation on introduction and transmission of virus to pigs. We have concluded that virus had been introduced from humans to pigs, possibly from October to November, 2009 in our country. There were direct and indirect factors including the vehicles transporting veterinary medicine, feed, etc. related to transmission of virus from farm to farm. However, breeding pigs seem to be extrinsic to transmitting factors. Upon the epidemiological investigation, the off-limits of visitors to farms and the disinfection is thought to be critical for blocking the introduction and transmission of novel influenza A/H1N1. In addition, collecting and analyzing the genetic informations of influenza virus is important for predicting and handling the new pandemic influenza in the future.
        4,000원
        9.
        2010.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This paper describes an investigation of an outbreak of foot-and-mouth disease (FMD) in Republic of Korea in January 2010. In this paper, we investigated introduction to the index farm from overseas countries, transmission from index farm to other outbreak farms. The introduction factors were divided direct, indirect factors or airborne spread factor. Based on the epidemiological data, clinical information and other data, in these introduction factors, it was likely that outbreak of FMD in index farm was due to international goods or employees from overseas countries (including China). There were other suggested causes in index farm. But it was less likely that outbreak of FMD in index farm have occurred by other causes. The transmission factors from index farm to other farms were also divided direct, indirect factors or airborne spread factor. In these transmission factors it was possible to make assumptions from index farm to other outbreak farms that the FMD virus was transmitted through animal treatment, persons concerned and persons (who were) attended farmers’ assembly.
        4,000원
        10.
        2015.12 KCI 등재 서비스 종료(열람 제한)
        This study aims to assess Green-Tourism accessibility of Rural Experience Village and then prepare improvement methods. To do this study, we surveyed 25 operators of Rural Experience Village in Chungbuk. We used 21 issues in all for analysis and the following shows a summary of major results. Rural Experience Village has a generally hard time conducting facility maintenance. Countermeasures for maintenance are required to run smoothly. Since Rural Experience Village has difficulty attracting visitors to the village, countermeasures are needed to attract visitors through business promotion. The results of assessing Green- Tourism accessibility showed us that some villages are a lot more accessible than others. Therefore, it is necessary that there should be improvements of Green -Tourism accessibility by attracting visitors and increasing operating days so that Green-tourism accessibility can be enhanced. In spite of its high level of accessibility since Rural Experience Village belonging to Goesan has low profitability, it is especially imperative that we establish more positive project promotion to cover it.
        11.
        2015.03 KCI 등재 서비스 종료(열람 제한)
        In this study, we try to quantify resident's conflict by rural development project based on previous researches about community capacities required for residents and social networks in rural village for suggesting efficient project model. we analyzed conflict elements in six category such as 'conflict in residents', 'conflict in residents and leaders', 'conflict in leaders', 'conflict in villages', 'conflict in development fund', 'conflict in village by common income project'. These results also analyzed by personal background(age, role, education, income) of respondent in questionary survey. Results show that 'conflict in residents and leaders', 'conflict in leaders', 'conflict in development fund' are perceived differently by age, role, education, and income in 5% significance level. Especially, relatively young age(below 40 years old) expressed clearly about conflict and high scored in item of 'residents and leaders'. Regression model show statistical significance(F=39.807, P=0.000) in influence relation analysis of conflict, network, leadership, and project fund. In this model, network β=-0.237, leadership β=-0.375, project fund β=-0.000 show network and leadership have negative relation to conflict but project fund is difficult to find relation with conflict. In this study, we defined social vulnerability using conflict, network, and leadership and verified the vulnerability of rural village applying regional community capacity in analysis results; vulnerability increased by the size of region and show inverse correlation to future vision of residents.
        12.
        2014.12 KCI 등재 서비스 종료(열람 제한)
        The purpose of this study was to develop survey tools for diagnosis of capacity levels in business promotion of rural residents when performing a rural development project of a regional unit. The cases of previous studies were analyzed to select community capacity indicators related to a rural development project. Five indicators were derived : social capital, consciousness of participation, community spirit, and leadership. Based on the five indicators, measurement items of various capacities were selected and 54 survey items were selected through evaluation of experts twice. The pilot tests were conducted and targeted at Jeonnam song ho-jung village and Gyeongnam Haegeumgang village to identify derived survey items. In addition, descriptive statistic analysis and reliability analysis were conducted. As a result, survey items were corrected by reducing 10 items of the total 54 items. This results showed that using this tool could help us understand capacity levels of rural residents.
        13.
        2014.11 KCI 등재 서비스 종료(열람 제한)
        By a SLAM (simultaneous localization and mapping) method, we get a map of an environment for autonomous navigation of a robot. In this case, we want to know how accurate the map is. Or we want to know which map is more accurate when different maps can be obtained by different SLAM methods. So, several methods for map comparison have been studied, but they have their own drawbacks. In this paper, we propose a new method which compares the accuracy or error of maps relatively and quantitatively. This method sets many corresponding points on both reference map and SLAM map, and computes the translational and rotational values of all corresponding points using least-squares solution. Analyzing the standard deviations of all translational and rotational values, we can know the error of two maps. This method can consider both local and global errors while other methods can deal with one of them, and this is verified by a series of simulations and real world experiments.
        14.
        2014.09 KCI 등재 서비스 종료(열람 제한)
        The Purpose of this study is to analyze of Specialization and Diversity of Rural Amenity Resources Planning. It will be performed analysis of the degree of specialization and diversity in each city and district of Chungcheongnam-do Province. Specialization and diversity indices were calculated by separately category of rural amenity resources into natural, cultural, and societal resources. The results of calculating the specialization degree of rural amenity resources based on a location index showed that eleven regions (Asan City, Buyeo District, Gyeryong City, Gongju City, Nonsan City, Boryeong City, Seocheon District, Seosan City, Seajong District, Cheongyang District and Yesan City) specialized in natural resources; four regions (Geumsan District and Hongseong Distriect) specialized in cultural resources; and six regions (Dangjin District, Cheonan City) specialized in societal resources. Examining resource specialization degrees by regions, there was a high number of regions specialized in natural and societal resources while those specialized in cultural resources were the rarest. Examining the calculation results for the tendency of resource specialization degree by areas showed that, with natural and cultural resources specialized regions, the average specialization degree showed a clear distinction with a 2.19 natural resource specialization degree and a 2.05 societal resource degree; However, in contrast, areas specialized in cultural resources-with an average degree of 1.52-were judged as not being especially more specialized than the average degree of Chungcheongnam-do Province. Also, there was seen a great gap between regions with high diversity and regions with low diversity of rural amenities, and measures to solve this difference is required.
        15.
        2014.06 KCI 등재 서비스 종료(열람 제한)
        There are direct and indirect approaches to measure the quality of rural life with comparison of urban. One of the direct approach is to survey living satisfaction of rural residents. Survey result is also important factor for the understanding of local needs in rural development. Rural Development Adminstration(RDA) has developed a survey table with 71 survey items for measuring the satisfaction of rural residents. In rural field forum which have conducted for finding the direction of rural development, the understanding of local needs with measuring the satisfaction of rural residents is important. But developed survey table is difficult to be applied in rural field forum not only many survey items but also overlapping in survey range. The purpose of this study is to suggest a field-applicable survey table in rural field forum based on results of RDA. Survey items were selected based on the importance score of RDA survey table, and weighting values were applied to each survey items. Finally, we suggested 31 items based on results with principle component and reliability analysis.
        16.
        2013.12 KCI 등재 서비스 종료(열람 제한)
        According to the increase of rural experience, that is important in satisfying needs of green tourism and vitalizing rural economy to use closed school in rural area as experience facility. For using closed school as experience facility, political and institutional assistants are needed in effective equipments and stable operation based on multi-perspective approach and analysis. In this study, we try to evaluate green-tourism accessibility of rural experience facility remodeled from closed school considering regional population and spatial characteristics. In evaluating process, gravity potential model are adapted with considering group size of customer and distance-friction coefficient. Distance-friction coefficient is a function of user restriction which depend on possible activity in each experience facility. Green tourism accessibility of experience facility is calculated with summation of accessibility to each region, and we analyzed it as a group by closed school type and location with application in Chungcheongnam-do. We found a correlation between green tourism accessibility of rural closed school and their income.
        17.
        2013.12 KCI 등재 서비스 종료(열람 제한)
        As facilities performing the production, processing, preservation, and shipment of agricultural products; agricultural facilities are categorized into planting facilities and livestock facilities based on the management target. Agricultural facilities are set in farmlands, and facility users mainly complain about the legal or institutional restrictions on farm rather than their own facilities itself. From 2009 to 2012, the Ministry of Agriculture Food and Rural Affairs (MAFRA) published the "Casebook of farmer Complaints on Farmlands" in order to help answer farmers' questions and support public workers' workloads. However, contents related to agricultural facility installed in farmland are currently not dealt with in particular. Among agricultural facilities, demands of property rights with livestock facilities have risen due to construction permissions, operational restrictions, and high initial investment costs; and relevant laws were revised and are now being executed. However, for planting facilities such as mushroom facilities, ginseng facilities, and greenhouses; farmer complaints related to property rights are constantly increasing because revisions to relevant laws are not being made despite the rising diversity of construction materials through technical developments as well as the rising scale of assets-i.e. mechanization, automation, and the application of New Regeneration Energies according to capital influx. In this study, the current state of relevant agricultural facility legislation were organized and their drawbacks deduced in order to propose improvements of Agricultural Facility Legislation. The result of interviewing with public workers and farmers show that agricultural facilities should be regarded as extensions of farmlands rather than as facilities built in land where development actions were being taken. Alternatives able to reflect these opinions were suggested through expert consultation.
        18.
        2013.06 KCI 등재 서비스 종료(열람 제한)
        The purpose of this study is to conduct an analysis of rural village's community status and consciousness through a questionnaire survey of community leaders and members. Nine types of rural village communities were selected in Korea through a pre-survey of amenity resources data from the Rural Development Administration. Survey items that could determine characteristics of rural village communities were derived from a literature survey of rural village community systems. A questionnaire survey was conducted for 12 Eup-Myeon in Yesan Gun and responses were gathered from 66 community leaders and 1,222 community members. The results derived from the data collected from the community leaders show that 50% percent of rural village communities have been operating for over 25 years, and that community works such as group purchases are carried out based on emotional sympathies between residents. The results derived from the data collected from community members show that on average, community activities are carried out at places that are between 30 and 60 minutes away. Most members are satisfied with regard to the status of their rural village community. A correlation analysis showed that the rural village community satisfaction depended on travel time, community fee, and activity time.
        19.
        2013.03 KCI 등재 서비스 종료(열람 제한)
        School closings in rural area continue to occur due to drops in population in those areas. Many studies have been done in order to effectively utilize such closed schools. However, there is a lack of studies targeting operators of the closed facilities for revitalization. Therefore, the goal of this research is understanding the real operational status of and finding solutions for the closed schools after studying the current operational status of the closed schools by conducting surveys with their operators. The survey was performed with closed-school-operators in Chungcheongnam-Do as the target; and the analysis was conducted regarding the acquisition type of the closed schools (purchase, lease), building condition, repair and construction status, annual visitors, operational days, operational fees, seasonal ups and downs, operational profits, and satisfaction of local government support. The results showed that there were differences with visitors and operational days along acquisition types as well as low operational profits and seasonal ups and downs including dissatisfaction of local government support. In this study, institutional and political improvement measurements were suggested for the effective operation of the closed facilities based on the main results.
        20.
        2012.12 KCI 등재 서비스 종료(열람 제한)
        Land suitability assessment assesses development, farming, and conservation suitability, considering land's soil, location, and possibility for use. It also implement segmentation of management regions into production, conservation, and plan management area. It is evaluated as a very significant system in establishing a land use system of sustainable development and development after planning in the aspect that it can establish proper land use plan. This study developed a recommendation model for development in agent-based model that interacts with surrounding lands. It also tried to summarize the area characteristic analysis and the results of land suitability evaluation, targeting three ri's in Yesan-Gun, and analyze the model's applicability by selection results. In order to recommend area for development that considers the use of the surrounding lands, it calculated development possibility indices that considered the ratings of all the lands in the target areas for each parcel and simulated the model. As a result, selected three areas in target region were suitable areas for development in land suitability assessment. In detail, ratings of the recommended parcels were 3, 4, and 5 ratings. As a result of examining the land status, it showed that all the three areas were plan management areas, thus easy for development. It is judged that the model for recommending area for development suggested in this study can be used as important basic data for setting the direction for development when establishing a regional planning.
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