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        검색결과 281

        201.
        2019.06 KCI 등재 서비스 종료(열람 제한)
        This study examined the efficiency of satellite images in terms of detecting wheat cultivation areas, and then analyzed the possibility of climate change through an correlation analysis of time series climate data from the western regions of Gyeongnam province, Korea. Furthermore, we analyzed the effect of climate change on wheat production through a multiple regression analysis with the time series wheat production and climate data. A relatively accurate distribution was achieved on the wheat cultivation area extracted through satellite image classification with an error rate of less than 10% in comparison to the statistical data. Upon correlation analysis with time series climate data, significant results were displayed in the following changes: the monthly mean temperature of the seedling stage, the monthly mean duration of sunshine, the monthly mean temperature of the growing period, the monthly mean humidity, the monthly mean temperature of the ripening stage, and the monthly mean ground temperature. Accordingly, in the study area, the monthly mean temperature, precipitation, and ground temperature generally increased whereas the monthly mean duration of sunshine and humidity decreased. The monthly mean wind speed did not display a particular change. In the multiple regression analysis results, the greatest effect on the production and productivity of wheat as climate factors included the annual mean humidity of the seedling stage, the annual mean temperature of the wintering period, and the annual mean ground temperature of the ripening stage. These results demonstrate that there is a change in wheat production depending on the climate change in the study area. in addition, it is determined that this study will be used as important basic data in the resolution of food security problems based on climate change.
        202.
        2019.04 서비스 종료(열람 제한)
        This paper presents an automated determination technique of optimal subset sizes for digital image correlation (DIC) analysis of speckle patterned images. The smaller subset size would typically have the higher DIC accuracy with respect to local minute deformation, but insufficient speckle pattern information within the excessively small often augment DIC errors due to lack of correlation features. Therefore, optimal subset size determination is crucial for the precise DIC analysis. To automate the optimal subset size determination process, first, the reference and test speckle pattern images are obtained from the target structure surface with a certain time interval. Then, an initial seed point which will be used for the subset center point is assigned on the reference speckle pattern image. Subsequently, normalized cross correlation (NCC) between the reference and test images is performed by increasing subset sizes from the seed point. Next, the matching distance between the two images is calculated using the maximum correlation coefficient. As the subset size increases, the matching distance between the two subsets converges a certain value. It physically means that the sufficient correlation features will be included in the subset. Finally, the optimal subset size can be determined by selecting the minimum subset size where the matching distance value starts to be converged. The proposed technique is experimentally validated using an aluminium plate with sprayed speckle pattern.
        203.
        2018.12 KCI 등재 서비스 종료(열람 제한)
        We investigated the effects of heavy metals in cement in the last 3 years and the amount of waste in the cement manufacturing process. The result shows that the average Cr6+ content in cement products is controlled at 10 mg/kg. Cu and Pb have lower detection tendency in white cement than in ordinary portland cement. In addition, heavy metals such as Cd show a certain level of detection regardless of the input wastes. Copper slag and phosphate gypsum are the main influencing factors on the heavy metals in cement products. In auxiliary fuels, plastics waste and wood waste are considered to affect heavy metals in cement products. Alternative raw materials are considered to be affected by the alternative raw materials managed as byproducts. In the case of supplementary fuels, auxiliary fuels managed as waste instead of auxiliary fuels managed as byproducts affect the heavy metals in cement. This study examined the input amount without considering the heavy metals in each waste. Therefore, the result may vary in different situations, and further research must be conducted to supplement the findings. However, if the heavy-metal contents in the waste are constant, it can be used as a reference material for the control of heavy metals in cement products.
        204.
        2018.12 KCI 등재 서비스 종료(열람 제한)
        A Quantile-based Matching (QM) method has been widely used to correct the biases in global and regional climate model outputs. The basic idea of QM is to adjust the Cumulative Distribution Function (CDF) of model for the projection period on the basis of the difference between the model and observation CDFs for the training period. Therefore, the CDF of observation on training period plays an important role in quantile-based matching. Also, ensembles are highly correlated because ensemble forecasts generated from a combination of randomly perturbed initial conditions and different convective schemes in numerical weather model. We discuss the dependence of the bias correction results obtained from Qunatile-based Matching when there is correlation between ensembles and the variance of observation is larger than that of model. A simulation study is employed to understand the relation and distributional characteristics of observation and model when applying Quantile-based Matching method.
        205.
        2018.12 KCI 등재 서비스 종료(열람 제한)
        본 연구는 심장 혈관 조영술의 투시 영상과 씨네 영상을 획득하는 데 있어서 초당 프레임 횟수를 변화함에 따라 흡수선량과 획득 영상의 화질의 추이를 살펴보는 것을 목적으로 한다. 또, FOV 확대와 Live Zoom이라는 두 가지 확대 모드에 따른 변화도 고찰 대상으로 한다. 인체모형 팬텀을 심장 혈관 조영장치 위에서 초당 프레임 횟수를 7.5, 15, 30 f/s로 설정하고 두 가지 확대 모드에 대하여 각각 5회씩 촬영하였다. 선량의 척도로서는 흡수선량과 에어 커머가 사용되었고, 화질 평가의 척도로는 잡음의 세기로서의 표준 편차(SD), 신호 대 잡음비(SNR)와 대조도 대 잡음비(CNR) 등을 활용하였다. 초당 프레임 횟수가 30부터 15, 7.5 f/s로 감소되었을 때, DAP와 에어 커머는 동일한 비율로 감소하였으나, 화질의 척도인 SD, SNR과 CNR은 거의 변화가 없었다. 확대 모드에의 의존도에 관해서는, Live Zoom이 FOV 확대와 비교하였을 때, DAP, 에어 커머와 SD에 대해서는 통계적 의미 있는 차이를 보이지 않았으나, SNR과 CNR에 있어서는 통계적 유의미한 개선을 보였다. 이러한 실험 결과에 의하여, 초당 프레임 횟수는 화질의 열화 없이 되도록 낮게 설정하는 것이 가능하며, 확대 모드도 추가적인 선량 없이 실시간 확대가 가능한 Live Zoom 모드를 적극적으로 활용 가능하며 이는 화질의 여러 척도의 저하를 가져오지 않음을 알 수 있었다.
        206.
        2018.11 KCI 등재 서비스 종료(열람 제한)
        The real-time monitoring of surface vegetation is essential for the management of droughts, vegetation growth, and water resources. The availability of land cover maps based on remotely collected data makes the monitoring of surface vegetation easier. The vegetation index in an area is likely to be proportional to meteorological elements there such as air temperature and precipitation. This study investigated relationship between vegetation index based on Moderate Resolution Image Spectroradiometer (MODIS) and ground-measured meteorological elements at the Yongdam catchment station. To do this, 16-day averaged data were used. It was found that the vegetation index is well correlated to air temperature but poorly correlated to precipitation. The study provides some intuition and guidelines for the study of the droughts and ecologies in the future.
        207.
        2018.11 KCI 등재 서비스 종료(열람 제한)
        수원과 수용가 간 연결성은 비정상상황 시 상수도관망의 기능 유지 정도를 나타내는 시스템 특성 중 하나이다. 상수도관망은 점과 선으로 구성된 그래프로 간략화 될 수 있기 때문에, 연결성 평가를 위해 주로 그래프 이론이 적용되었다. 하지만, 대부분의 연구는 상수도관망에 적합하지 않은 무 향-비가중 그래프 이론을 적용하였다. 본 연구에서는 유향-가중 그래프 이론을 상수도관망에 적용하였으며, 이를 기반으로 복잡한 수리해석 없이 상수도관망 연결성을 평가할 수 있는 지표인 SNSP (Source to Node Shortest Pathway)와 이의 역수인 SNSP-Degree (SNSP-D)를 제안하였다. 국내 J시 42개의 상수도관망을 이용하여 개발된 SNSP와 기존 상수도관망 성능평가지표 사이의 상관성 분석을 수행 및 검증하였다. 기존 상수도관 망 성능평가지표는 수리해석 결과를 지표 계산에 이용하는 3개의 회복력(Resilience) 지표와 에너지 효율 지표이다. 분석 결과, SNSP의 역수인 SNSP-D의 합과 기존 상수도관망 성능지표 사이에 평균적으로 0.87 이상의 높은 피어슨 상관계수(Pearson Correlation Coefficient, PCC) 값이 도출되었다. 특히, 회복력 지표 중 하나인 Modified Resilience Index (MRI)와 에너지 효율 지표의 경우 PCC 0.93 이상의 높은 상관관계를 가지는 것으로 나타났다. 또한 다중 회귀 분석을 통해 SNSP-D와 회복력 및 에너지 효율 간의 상관성에 영향을 미치는 수리학적 변인을 확인하였다. 본 연구에서 제안한 SNSP 지표가 상수도관망의 대략적인 회복력 및 에너지 효율 수준을 알려줄 수 있는 지표로 실무에서 널리 활용될 것으로 기대된다.
        208.
        2018.10 KCI 등재 서비스 종료(열람 제한)
        게임 봇은 게임에서 사용되는 재화 또는 아이템 등을 대량으로 유통시키며 게임 재화 및 아이템의 가치를 하락시키는 한편 아이템을 획득하기 위해 봇끼리 몰려다니면서 몬스터를 사냥하고 아이템을 채집하므로 일반 유저들이 정상적으로 콘텐츠를 즐기는 활동을 방해해 왔다. 그러나 봇의 증가가 구체적으로 어떤 유형의 유저에게 영향을 미치는지, 그리고 어떤 활동 유형을 감소시키는지에 대한 연구는 알려진 바가 없었다. 이에 따라 본 연구에서는 게임 유저들의 접속 데이터를 토대로 유형을 분류하고 봇의 증가에 따른 유저 이탈과의 상관관계를 분석함으로써 유저들의 게임 이용을 유도하는 실무적인 시사점을 제공한다.
        209.
        2018.10 KCI 등재 서비스 종료(열람 제한)
        최근 핵의학에서 진단가치의 향상을 위해 PET-CT에서 이용하고 있는 반정량지표인 SUV를 SPECT-CT에 도입하여 적용하고 있다. 따라서 두 가지 스캐너의 SUVmax를 팬텀실험을 통해 상관관계를 분석하여 임상적용 가능성을 평가하였다. 부피가 다른 6개의 구로 제작된 팬텀에 방사성의약품 (18F, 99mTc)을 배후방사능을 고려하여 8:1과 4:1 비율로 주입하고, 임상 프로토콜을 기반으로 PET-CT와 SPECT-CT 스캐너로 양성상을 획득한 후 관심영역을 ROI와 VOI로 구분하여 SUVmax를 측정하여 분석하였다. 실험결과 두 가지 스캐너로 측정한 SUVmax는 통계적으로 유의한 차이가 없었다 (P>0.05). 따라서 PET-CT와 SPECT-CT의 SUVmax 는 유의한 수준 내에서 일정한 상관관계를 가지며, 같이 평가되었다. 따라서 SPECT-CT를 이용한 SUVmax 정량 분석은 본 연구를 통해 일반화하기에 제한적이지만 임상에 실험적 정보를 제공할 수 있으므로, 임상실험과 같은 관련 실험을 통한 추가 연구가 필요할 것으로 판단된다.
        210.
        2018.05 서비스 종료(열람 제한)
        1996년부터 환경부에서 시행된 전국폐기물통계조사는 매 5년을 주기로 조사를 실시하며 폐기물의 종류별 발생 및 처리현황 파악 및 폐기물 발생원에 따른 발생원단위를 산정한다. 우리나라 현행 「폐기물관리법」 상에서는 폐기물을 생활계와 사업장계로 분류하고 있으며 사업장폐기물은 사업장일반계, 건설폐기물계, 지정폐기물계로 분류하고 있음. 지정폐기물계는 폐유, 폐산 등 환경을 오염시킬 수 있는 폐기물과 인체조직, 실험동물 사체 등의 의료폐기물로 규정하고 있다. 사업장 폐기물의 경우 올바로 시스템에 매년 실적보고를 하며 전국폐기물통계조사는 실적보고 자료와 별도의 추가 설문조사를 통해 사업장의 경제데이터를 확보한다. 제 5차 전국폐기물통계조사에서는 객관성 높은 통계 자료를 얻기 위해 모든 폐기물에 동일한 방법론을 적용했던 기존의 조사・분석 방법에서 사업장에 특성에 따른 조사를 실시하였고 무응답 조정 가중치 산출, 캘리브레이션 가중치 산출, 변동계수 산출 등 통계적 기법을 추가하였다. 의료폐기물과 지정폐기물의 경우 분석 시 공동운영기구 등 실적보고 대행업체를 고려, 원단위 오차를 줄였다. 의료폐기물은 격리의료폐기물, 병리계폐기물, 생물화학폐기물 등 총 8종이 있다. 전국폐기물 통계조사에서는 의료폐기물을 배출하는 업체를 종합병원, 병원, 의원 등 9개의 항목으로 구분하였고, 종사자수, 건물면적, 병상 수 등의 경제데이터를 수집하여 경제데이터 당 발생원단위를 산정하였다. 제 5차 전국 폐기물 통계조사에서 처음으로 신설된 항목은 병상 수(bed 수)이다. 법적으로 의료기관 구분 시병상 수를 기준으로 나눈다. 특히 의료기관의 경제데이터별 발생원단위를 살펴보면 종사자수, 건물면적보다 병상 수와 의료폐기물 발생량의 상관성이 높음을 볼 수 있다. 따라서 향후 통계조사에서 병상 수 항목을 유지하여 시계열성을 확보한다면 보다 활용도 높은 통계결과를 얻을 수 있을 것으로 사료된다.
        211.
        2018.04 서비스 종료(열람 제한)
        In this study, the partial correlation between the expansion and the vertical displacement excluding the temperature and the correlation between the expansion and vertical displacement and the average temperature of the reinforced truss member was analyzed. The correlation coefficients between temperature and expansion, temperature and vertical displacement were .929 and .874, respectively. The correlation coefficient between vertical displacement and expansion was 0.860 and partial correlation coefficient excluding temperature effect was 0.268.
        212.
        2018.04 서비스 종료(열람 제한)
        As the frequency and period of earthquakes are increasing compared to the past, interest in the safety of rescue facilities including bridges a lot of. The correlation between the statistical index and the surrounding environment was analyzed by using the seismic acceleration measurement data of the bridge.
        213.
        2018.04 서비스 종료(열람 제한)
        In Korea, inspection and precise safety diagnosis is regularly carried out to maintain and manage the main tunnel(NATM) which has been passed ten years after completion. In this study, we collected the laboratory test results of the concrete lining in the existing road and railway tunnels, and analyzed the correlation between compressive strength and unit mass of concrete. It is hoped that it will be used for efficient maintenance and management work of tunnels in the future.
        214.
        2017.09 서비스 종료(열람 제한)
        All bridges are inevitably undergoing deterioration over time. Therefore, it is necessary to predict the maintenance control and to properly manage the maintenance control cost by deriving the appropriate repair and reinforcement timing. The deterioration of bridges appears to vary according to the years of use of bridges and the exposed environment. In this study, the correlation between the deterioration factor of the winter season and the damage rate of the bridge deck was derived from 1117 total bridge data collected through the GPR(Ground Penetration Radar) system.
        215.
        2017.07 KCI 등재 서비스 종료(열람 제한)
        In this study, we analyzed the content of five hazardous heavy metals (Pb, As, Hg, Cd, and Cu) in cement products distributed in Korea over the last five years. The types and amounts of waste inputted into a cement kiln or added as alternative fuels and secondary raw materials were investigated, and the correlation between heavy metal content and input waste were analyzed. The measured heavy metal content in cement products were 26.9-95.0 mg/kg for lead, 6.08-19.15 mg/kg for arsenic, 0.0339-0.2617 mg/kg for mercury, 2.937-4.392 mg/kg for cadmium, and 22.25-267.42 mg/kg for copper. In addition, based on correlation analysis results between the heavy metal content of cement products and added input wastes, major wastes that affected the heavy metal content among the 11 types of waste were iron, coal ash, waste tires, waste plaster, desulfurization gypsum, and waste synthetic resin.
        216.
        2017.04 서비스 종료(열람 제한)
        In this study, The correlation between drainage clogging of drain tunnel and leakage of lining was analyzed. As a result of analysis, the position of clogged drainage hole, leakage and efflorescence location are similar. When repairing leakage of lining, the maintenance method should be selected considering the clogging of tunnel drainage.
        217.
        2016.08 KCI 등재 서비스 종료(열람 제한)
        This study analyzes the PM10 characteristics (particulate matter with aerodynamic diameter less than 10 ㎛), concentration, and emissions in eight large South Korean cities (Seoul, Incheon, Daejeon, Daegu, Gwangju, Ulsan, Busan, Jeju). The annual median of PM10 concentration showed a decline of 0.02~1.97 ㎍/㎥ in the regions, except for Incheon, which recorded an annual 0.02 ㎍/㎥ increase. The monthly distribution levels were high in spring, winter, fall, and the summer, but were lower in summer for all regions except for Ulsan. These differences are thought to be due to the dust in spring and the cleaning effect of precipitation in summer. The variation in concentrations during the day (diurnal variation) showed that PM10 levels were very high during the rush hour and that this was most extreme in the cities (10.00 and 18.00-21.00). The total annual PM10 emissions analysis suggested that there had been a general decrease, except for Jeju. On-road mobile (OM) sources, which contributed a large proportion of the particulates in most regions, decreased, but fugitive dust (FD) sources increased in the remaining regions, except for Daegu. The correlation analysis between PM10 concentrations and emissions showed that FD could be used as a valid, positive predictor of PM10 emissions in Seoul (74.5% (p<0.05)), Dajeon (47.2% (p<0.05)), and Busan (59.1% (p<0.01)). Furthermore, industrial combustion (IC) was also a significant predictor in Incheon (61.7% (p<0.01)), and on-road mobile (OC) sources were a valid predictor in Daegu (24.8% (p<0.05)).
        218.
        2016.07 KCI 등재 서비스 종료(열람 제한)
        Environmental policy implementation has been strengthened to protect the source waters in Korea and to improve their water quality. Increasing of non-point source caused water quality problem continuously. Research on runoff from forests, which occupy over 65% of the land in korea, is insufficient, and studies on the characteristics and influences of storm runoff are necessary. In this study, we chose to compare the effects of land use in the form of two types of forest distribution and then gathered data on storm characteristics and runoff properties during rainfall events in these areas. Furthermore, the significance and influences of the discharges were analyzed through correlation analysis, and multilateral runoff characteristics were examined by deducing a formula through CODMn and TOC regression analysis. At two forest points, for which the basin areas differed from each other, flow changed according to storm quantity and intensity. The peak discharge at point A, where the basin area was big, was high, whereas water-quality fundamental items (BOD, CODMn, and SS) and TOC density were high at point B where the slope and storm intensity were high. Effects of dissolved organic matter were determined through correlation analysis, and the regression formulas for CODMn and TOC were deduced by regression analysis. It is expected that the data from this study could be useful as basic information in establishing forest management measures.
        219.
        2016.06 KCI 등재 서비스 종료(열람 제한)
        This research is to conduct a survey on Plant Attitude Scale, Emotional Intelligence, Aggression Scale and Verbal Aggressiveness Scale of 540 elementary schoolchild and to analysis on credibility, descriptive statistics and correlation by SPSS (Statistical Package for the Social Sciences) Version 21. Both Plant Attitude Scale (Importance of plant, function of urban trees, interest on the plant, utilization of plant) and Emotional Intelligence (emotion recognition, empathy, emotion control ability) present significant correlation. The higher grade of plant attitude including higher emotional intelligence. in the entire of plant attitude, the most of subcategories of emotional intelligence indicate significant correlation. Importance of plant and interest on the plant has more significant correlation with emotional intelligence. As Plant Attitude Scale and Aggression Scale (physical aggression, anger, hostility) present the significant negative correlation, it shows that the higher plant attitude, the lower aggression. The plant attitude indicates very significant correlation between physical aggression and anger in physical aggression and anger as well as importance with plant. In case of function with urban trees, it shows the higher physical aggression, anger and interest on the plant, the lower physical aggression. While Plant Attitude Scale and Verbal Aggressiveness Scale (Swear, ridicule, taunt, threat, curse) present significant negative correlation, the higher plant attitude, the lower verbal aggressiveness. The plant attitude indicates that there is significant negative correlation in swear, ridicule, curse among the verbal aggressiveness. In the subordinate scope, especially in importance of plant, it shows significant difference that grade of sear gets lower as the higher swear and curse including case of swear, ridicule and function of urban trees and also there are higher points with sear, ridicule, curse and utilization of plant in case of interest on the plant.
        220.
        2016.04 서비스 종료(열람 제한)
        Recently, it was found that the Vulnerability Index(VI) of Preliminary assessment for water pipelines seismic performance in domestic had lacks of correlation of detailed safety assessment. The purpose of this study is to propose a reasonable VI by analysing on correlation between existing VI and safety factor.