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        검색결과 1,343

        221.
        2016.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Naval combat system developed in-country is progressing at an alarming rate since 2000. ROK navy will be achieved all vessels that have combat system in the near future. The importance of System Engineering and Integrated Logistics Support based on reliability analysis is increasing. However, reliability analysis that everyone trusted and recognized is not enough and applied practically for development of Defense Acquisition Program. In particular, Existing Reliability Analysis is focusing on reliability index (Mean Time Between Failure (MTBF) etc.) for policy decision of defense improvement project. Most of the weapon system acquisition process applying in the exponential distribution simply persist unreality due to memoryless property. Critical failures are more important than simple faults to ship’s operator. There are no confirmed cases of reliability analysis involved with critical failure that naval ship scheduler and operator concerned sensitively.Therefore, this study is focusing on Mean Time To Critical Failure (MTTCF), reliability on specific time and Operational Readiness Float (ORF) requirements related to critical failure of Patrol Killer Guided missile (PKG) combat system that is beginning of naval combat system developed in-country. Methods of analysis is applied parametric and non-parametric statistical techniques. It is compared to the estimates and proposed applications. The result of study shows that parametric and non-parametric estimators should be applied differently depending on purpose of utilization based on test of normality. For the first time, this study is offering Reliability of ROK Naval combat system to stakeholders involved with defense improvement project. Decision makers of defense improvement project have to active support and effort in this area for improvement of System Engineering.
        4,200원
        222.
        2016.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구는 다중빔 음향측심 자료를 바탕으로 침몰선박의 정확한 형상 및 해저지형에 대한 정보를 분석하였다. 다양한 영상 자료처리를 통해 현재 침몰선박의 상태를 분석하였다. 해당 자료와 과거 조사 자료의 비교를 통하여 침몰선박 상태 변화 및 주변지형의 변화를 해석하였다. 분석대상 선박 중 퍼시픽프랜드호의 경우 조류에 의한 침·퇴적으로 인해 선수-선미의 지형변화가 뚜렷하게 나타나는 특징을 알 수 있었다. 그리고 제7해성호의 경우 2011년 국립해양조사원 영상자료에서는 선수 일부가 유지된 상태였으나, 2015년 조사 영상에서는 선수 일부가 붕괴된 것을 확인할 수 있었다. 이는 오랜 기간 선박이 해저에 방치되면서 조류 및 화물의 하중 등과 지속적인 부식으로 선체가 붕괴된 것으로 추정된다. 따라서 잔존연료 유출 및 주변 해양오염이 발생할 수 있어 지속적인 모니터링이 필요할 것으로 판단된다. 침몰선박의 영상분석을 통해 침몰선박이 수심과 조류에 의한 영향을 많이 받은 지역일 경우 지질학적 특성과 퇴적물의 침·퇴적 양상에 따라 침몰선박의 구조 안전성에 상당한 영향을 줄 것으로 판단되며, 부식으로 인한 선체의 변화는 계속적으로 변화될 것으로 추정된다. 따라서 지질학적 특성을 고려한 잔존연료 유출 및 주변 환경 변화에 대하여 침몰선박의 변화에 따라 예측‧대응하는 기술의 개발이 필요하다.
        4,000원
        223.
        2016.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        최근 기후변화에 따라 전 세계적으로 큰 규모의 산불 발생이 증가하고 있으며, 우리나라도 산불발생이 전반적으로 증가하는 경향을 보인다. 최근 우리나라와 인접한 북한에서 발생한 산불이 비무장 지대 등의 국내 영토로 번지는 사건이 많이 발생하고 있다. 우리나라에서는 오픈 API(application programming interface)를 통하여 과거 산불발생 기록을 검색할 수 있으나 행정기관에서 수집한 자료여서 국내 지역으로 정보가 국한되어 있다. 이에 본 연구에서는 접근불능지역인 북한을 포함한 한반도의 산불발생에 대한 장기 시계열 정보를 생산하기 위하여 2000년부터 2015년까지의 MODIS(Moderate Resolution Imaging Spectroradiometer) 위성자료를 수집 및 재가공하여 일자별 산불발생 현황의 GIS 데이터베이스를 구축하고자 한다. 데이터베이스 구축을 위한 입력자료로서 Terra 위성의 MOD14A1 산출물과 Aqua 위성의 MYD14A1 산출물을 사용하였으며, 16년간의 일자별 영상을 일괄작업으로 재처리하여 산불의 발생일자, 발생 위치, 탐지 신뢰도, 방사열 에너지(fire radiative power: FRP) 등의 정보를 추출하고 이들을 결합하여 Shapefile 형태로 생성하였다. 본 연구에서 구축한 장기시계열 GIS 데이터베이스는 다른 연구자들에 의해 한반도 산불정보의 시공간 특성 분석에 활용될 수 있으며, 이를 위하여 인터넷에 결과 파일을 탑재하여 자유롭게 다운로드 가능하도록 하였다.
        4,000원
        224.
        2016.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study investigates important parameters used to determine an effective peak ground acceleration (EPGA) based on the characteristics of response spectra of historical earthquakes occurred at Korean peninsula. EPGAs are very important since they are implemented in the Korean Building Code for the seismic design of new structures. Recently, the Gyeongju earthquakes with the largest magnitude in earthquakes measured at Korea took place and resulted in non-structural and structural damage, which their EPGAs should need to be evaluated. This paper first describes the basic concepts on EPGAs and the EPGAs of the Gyeongju earthquakes are then evaluated and compared according to epicentral distances, site classes and directions of seismic waves. The EPGAs are dependant on normalizing factors and ranges of period on response spectrum constructed with the Gyeongju earthquake records. Using the normalizing factors and the ranges of period determined based on the characteristics of domestic response spectra, this paper draw a conclusion that the EPGAs are estimated to be about 30 % of the measured peak ground accelerations (PGA).
        4,000원
        229.
        2016.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        이 논문은 양구 고대리유적의 자료를 중심으로 북한강유역 청동기시대 천전리식 주거의 출현과정을 검 토한 글이다. 이에 앞서 양구 고대리유적에서 조사된 주거지 중 점토다짐구역이 시설되었으나 평면형태상 천전리식 주거와 차이를 보이는 동시에 정형성을 보이는 주거 형태를 고대리식 주거라 명명하였으며, 단계설정과 편년을 통해 고대리식 주거의 시간적 위치를 부여하고 점토다짐구역의 변화가 갖는 의미를 살펴 보았다. 고대리유적은 유물양상을 통해 총 4단계로 구분하였다. 이 중 고대리식 주거는 2단계에 출현해 역삼동식 주거와 공존함과 동시에 천전리식 주거의 이른 형태가 출현한다. 그러나 유물은 여전히 전기 후반의 양상을 보이며 천전리식 주거와 병존하는 3단계에서야 전환기적인 양상의 유물이 확인된다. 이러한 양상 을 종합해 2단계를 전기 후반~중기 전반, 3단계를 중기 전반으로 편년하였고, 고대리식 주거는 천전리식 주거가 정착한 4단계 중기 후반 이후 급격히 소멸한다. 고대리식 주거의 점토다짐구역은 2~3단계를 거치면서 평면형태상 점진적인 변화과정을 겪는다. 특히 주거지 내부 저장공의 위치가 점토다짐구역 외측으로 이동하는 현상과 유물분포양상은 주거의 규모 및 장단비 축소와 점진적인 공간의 기능분화에서 비롯된 점 토다짐구역의 축소와 이동현상으로 파악된다. 이상에서 그간 역삼동식 주거의 영향 하에 자체 발생한 것으로 유추했던 천전리식 주거는 역삼동식-고대리식 ․ 용암리식-천전리식 주거로 이어지는 시간적 ․ 계통적 연결선상에 있으며, 고대리식 주거는 용암 리식 주거와 더불어 천전리식 주거의 출현과정에서 상이한 공간분화를 거친 과도기적 주거형태로 판단된다.
        6,100원
        230.
        2016.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The purpose of this study was to determine the health behaviors and nutritional status related to dyslipidemia in Korean middle-aged adults (between 50 and 64 years old) from the Korean National Health and Nutrition Examinations Survey data (2007~2010). A total of 4,721 subjects were analyzed in this study. The subjects were divided into three groups (normal, borderline, and dyslipidemia) according to serum lipid levels. Parameters included in this study were drinking and smoking, anthropometric parameters, blood and nutritional parameters. The latter parameter included food/nutrients intake. All data was adjusted by sex, region, education level, and age. General linear model and logistic regression model were used for statistical analysis. The dyslipidemia group was comprised of more men than women. By contrast, the borderline group was comprised of more women than men (p<0.001). No significant differences were observed for other general characteristics. There were more smokers and drinkers(drinking per time) in the dyslipidemia group (p<0.05). Anthropometric data showed significant difference, ie, height (p<0.05), weight, body mass index, waist circumference, percent body fat, and blood pressure were higher in the dyslipidemia group (p<0.001). Only blood urea nitrogen showed no significant difference among groups. The HbA1c (p<0.01), fasting blood glucose, GOT, GPT, creatinine levels were higher in the dyslipidemia group (p<0.001). So it is required for the management of obesity in dyslipidemia group. The dyslipidemia group ate less sea food (p<0.05). The nutrients intake of energy and protein, thiamin, riboflavin, niacin, calcium, phosphorus were lower in the dyslipidemia group (p<0.05). Therefore, to lower dyslipidemia prevalence rates, it is necessary to increase the intake of foods containing ω-3 fatty acids. We also suggest a meal management program and nutritional education to recognize the risk of dyslipidemia, especially for people such as the individual in the borderline and dyslipidemia study groups. Key words: dyslipidemia, Korean middle-aged adults, nutritional status, health behaviors
        4,200원
        231.
        2016.10 구독 인증기관·개인회원 무료
        농촌진흥청 작물보호과에 1962년 이래로 보관되어 온 전국 159개 예찰답의 유아등 성적을 분석하여 그간 국내의 기후변화와 벼멸구, 흰등멸구, 혹명나방 등의 주요 벼 비래해충의 초기 비래일 변화를 살펴보았다. 토착해충과 달리 비래해충은 유아등에 유인되는 날짜의 변화가 기후변화와 반드시 일치하거나 연관성이 높음을 단정지을 수 있는 이론은 아직까지 없으나, 그럼에도 불구하고 국내에서 월동가능하며 중국에서의 비래량 또한 무시할 수 없는 애멸구의 경우에는 유아등에 유인되는 초기 개체수의 피크 밀도가 지구온난화에 따른 해충발생시기 변화의 중요한 단서를 제공할 수 있다. 우리나라 남한지역을 편의상 9등분하여 조사한 결과 경남 및 전남지역 등 남부지역의 경우 애멸구의 본답이동시기가 1960년대에 비해 2010년대에는 약 10일정도 더 빨라짐을 알 수 있었고, 경기, 강원 등 북부지역의 경우에는 3~5일 정도 이동시기가 빨라졌음을 알 수 있었다. 따라서 지구온난화에 따른 해충발생상 변화 속도는 남부지역이 북부지역보다 더 빠르게 진행되고 있음을 알 수 있었다.
        232.
        2016.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The purpose of this study was to investigate the relationship between frequency of coffee consumption, metabolic biomarkers, and nutrition intake in adult participants in the combined 2007~2009 Korean National Health and Nutrition Examination Survey (KNHANES). Subjects (2,095 males and 3,297 females) were classified according to sex and frequency of coffee consumption (≤1 time/month, ≥2 times/month and ≤6 times/week, 1 time/day, 2 times/day, 3 times/day) using food frequency questionnaires. Nutrition intake was analyzed using 24 h recall data. The 3 times/day coffee consumption group had a significantly higher age, and frequency of smokers and drinkers compared to the ≤1 time/month coffee consumption group in both male and female participants. Males in the 3 times/day coffee consumption group had a significantly lower HDL-cholesterol level, but females had a higher waist circumference compared with the ≤1 time/month coffee consumption group. Males in the 3 times/day coffee consumption group had a significantly lower nutrient density of fiber, vitamin B2, vitamin C, calcium and phosphorus compared with the ≤1 time/month coffee intake group. Females in the 3 times/day coffee consumption group had a significantly higher nutrient density of fat and niacin, but lower nutrient density of carbohydrate, calcium, phosphorus, and iron compared with the ≤1 time/month coffee intake group. In males, the frequency of coffee consumption was not associated with the levels of metabolic biomarkers. In females, the frequency of coffee consumption was positively associated with diastolic blood pressure after adjustments for multiple confounding factors, including age, BMI, smoking status, alcohol consumption, physical activity and energy intake. Coffee consumption was associated with decreased diastolic blood pressure in females. These findings suggest the importance of an awareness of the association between coffee consumption and metabolic risk.
        4,000원
        233.
        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
        234.
        2016.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The purpose of this study was to evaluate the nutrient intake, diversity and prevalence of diseases according to noodle consumption using data from the Korean National Health and Nutrition Examination Survey (KNHANES) of 2010. Korean adults (>20) were classified into two groups, noodle group (NG) and non-noodle group (NNG). NG was found to have higher intakes of protein, calcium, iron, sodium, potassium, and niacin. The DVS and DDS according to noodle consumption were found to be 21.76 and 3.51 for NG, and 18.56 and 3.40 for NNG, this result was thought to show that the diet of NG was more satisfactory than that of NNG in terms of dietary diversity. In the bone mass of entire subjects, NG showed higher figures in the femoral neck and lumbar spine than NNG. For bone mineral density, NG exhibited higher figures in the femoral neck, and for T-scores, the values of NG was significantly higher in the femoral neck than those of NNG. However, the prevalence of osteoporosis of NG and NNG was 11.6% and 9.5%. The prevalence of osteopenia of NG and NNG was 43.0% and 51.7%. Thus, these results showed that overall bone health of NG was better than that of NNG. Dietary balance and quality were also more satisfactory in NG. These results showed that noodle consumption may have an impact on the prevalence of chronic diseases.
        4,000원
        235.
        2016.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        온난화와 같은 전지구적 변화는 기온과 강수 등 기상요소에 직접적으로 반영되어 곡물 수확량의 변화를 가져온다. 기후변화 시나리오에 기초한 선행연구들에서는 GCM (general circulation model)의 공간해상도 문제로 인하여 상세한 모의가 어려웠고, 시계열통계법을 활용한 연구들에서는 기후요소를 통합하여 수확량을 예측한 사례가 매우 드물었다. 이에 본 연구에서는 상세화된 기후재분석자료의 시계열모델링을 통하여 옥수수와 콩의 수확량 예측실험을 수행하였다. 미국 아이오와 주의 99개 카운티를 대상으로 1960년부터 2009년까지 50년간의 고해상도 기후재분석자료와 정부통계 수확량 DB를 구축하고, 시계열통계법인 VAR (vector autoregression)와 ARIMA (autoregressive integrated moving average)를 이용하여 다음해 수확량 예측실험을 10개 연도에 대해 수행하여 예측력을 평가하였다. VAR는 16-18%, ARIMA는 11-14% 의 오차율로 다음해의 수확량을 예측할 수 있는 것으로 집계되었으며, 옥수수의 경우 표토의 산성도, 심토의 점토와 나트륨 함유량 등의 토양특성 이 실제 수확량 및 예측정확도에 영향을 미치는 것으로 나타났다.
        4,300원
        236.
        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
        238.
        2016.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        With increasing interest, there have been studies on LiDAR(Light Detection And Ranging)-based DEM(Digital Elevation Model) to acquire three dimensional topographic information. For producing LiDAR DEM with better accuracy, Filtering process is crucial, where only surface reflected LiDAR points are left to construct DEM while non-surface reflected LiDAR points need to be removed from the raw LiDAR data. In particular, the changes of input values for filtering algorithm-constructing parameters are supposed to produce different products. Therefore, this study is aimed to contribute to better understanding the effects of the changes of the levels of GroundFilter Algrothm’s Mean parameter(GFmn) embedded in FUSION software on the accuracy of the LiDAR DEM products, using LiDAR data collected for Hwacheon, Yangju, Gyeongsan and Jangheung watershed experimental area. The effect of GFmn level changes on the products’ accuracy is estimated by measuring and comparing the residuals between the elevations at the same locations of a field and different GFmn level-produced LiDAR DEM sample points. In order to test whether there are any differences among the five GFmn levels; 1, 3, 5, 7 and 9, One-way ANOVA is conducted. In result of One-way ANOVA test, it is found that the change in GFmn level significantly affects the accuracy (F-value: 4.915, p<0.01). After finding significance of the GFmn level effect, Tukey HSD test is also conducted as a Post hoc test for grouping levels by the significant differences. In result, GFmn levels are divided into two subsets ( ‘7, 5, 9, 3’ vs. ‘1’). From the observation of the residuals of each individual level, it is possible to say that LiDAR DEM is generated most accurately when GFmn is given as 7. Through this study, the most desirable parameter value can be suggested to produce filtered LiDAR DEM data which can provide the most accurate elevation information.
        4,200원
        240.
        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