• 제목/요약/키워드: point sampling

검색결과 821건 처리시간 0.025초

자율주행자동차 정면충돌평가방안 마련을 위한 국내 정면충돌사고 심층분석 연구 (An In-depth Analysis of Head-on Collision Accidents for Frontal Crash Tests of Automated Driving Vehicles)

  • 박요한;박원필;김승기
    • 자동차안전학회지
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    • 제15권4호
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    • pp.88-94
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    • 2023
  • The seating postures of passengers in the automated driving vehicle are possible in atypical forms such as rear-facing and lying down. It is necessary to improve devices such as airbags and seat belts to protect occupants from injury in accidents of the automated driving vehicle, and collision safety evaluation tests must be newly developed. The purpose of this study is to define representative types of head-on collision accidents to develop collision standards for autonomous vehicles that take into account changes in driving behavior and occupants' postures. 150 frontal collision cases remained by filtering (accident videos, images, AIS 2+, passenger car, etc…) and random sampling from approximately 320,000 accidents claimed by a major insurance company over the past 5 years. The most frequent accident type is a head-on collision between a vehicle going straight and a vehicle turning left from the opposite side, accounting for 54.7% of all accidents, and most of these accidents occur in permissive left turns. The next most common frontal collision is the center-lane violation by drowsy driving and careless driving, accounting for 21.3% of the total. For the two types above, data such as vehicle speed, contact point/area, and PDOF at the moment of impact are obtained through accident reconstruction using PC-Crash. As a result, two types of autonomous vehicle crash safety test scenarios are proposed: (1) a frontal oblique collision test based on the accident types between a straight vehicle and a left-turning vehicle, and (2) a small overlap collision test based on the head-on accidents of center-lane violation.

Emotional Intelligence, Academic Motivation, and Achievement among Health Science Students in Saudi Arabia: A Self-Deterministic Approach

  • Mahrous, Rasha Mohammed;Bugis, Bussma Ahmed;Sayed, Samiha Hamdi
    • 대한간호학회지
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    • 제53권6호
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    • pp.571-583
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    • 2023
  • Purpose: This study used a self-deterministic approach to explore the relationship between emotional intelligence (EI), academic motivation (AM), and achievement among health science students. Methods: A descriptive cross-sectional study was conducted in three cities of Saudi Arabia (Dammam, Riyadh, and Jeddah). A convenience sample of 450 students was incorporated using the multistage cluster sampling technique. The online survey contained three sections: students' basic data and academic achievement level, the modified Schutte self-report inventory, and the Academic Motivation Scale lowercase. Results: This study revealed moderate overall scores for EI (57.1%), AM (55.6%), and grade point average (GPA) (57.6%). The overall EI score, its domains, and GPA had significant positive correlations with overall AM and intrinsic and extrinsic motivation (p < .01). Amotivation had an insignificant correlation with GPA (p < .05), but it was negatively correlated with EI and its domains (p < .01). Multiple regression analysis proved that EI domains predicted 5.0% of GPA variance; emotions appraisal and expression (β = .02, p = .024), regulation (β = .11, p = .032), and utilization (β = .24, p < .01). EI domains also predicted 26.0% of AM variance; emotions appraisal and expression (β = .11, p = .04), regulation (β = .33, p < .01), and utilization (β = .23, p < .01). Moreover, AM predicted 4.0% of the variance in GPA; intrinsic (β = .25, p = .004) and extrinsic (β = .11, p = .022) motivation. AM also predicted 25.0% of the variance in EI: intrinsic (β = .34, p < .01) and extrinsic motivation (β = .26, p = .026). Conclusion: EI and AM have a bidirectional influence on each other, significantly shaping the GPA of health sciences students in Saudi Arabia, where intrinsic motivation has a predominant role. Thus, promoting students' AM and EI is recommended to foster their academic achievement.

Using the Health Belief Model to Predict Tuberculosis Preventive Behaviors Among Tuberculosis Patients' Household Contacts During the COVID-19 Pandemic in the Border Areas of Northern Thailand

  • Nantawan Khamai;Katekaew Seangpraw;Parichat Ong-Artborirak
    • Journal of Preventive Medicine and Public Health
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    • 제57권3호
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    • pp.223-233
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    • 2024
  • Objectives: The coronavirus disease 2019 pandemic has exacerbated the rate of tuberculosis (TB) infection among close contacts of TB patients in remote regions. However, research on preventive behaviors, guided by the Health Belief Model (HBM), among household contacts of TB cases is scarce. This study aimed to employ the HBM as a framework to predict TB preventive behaviors among household contacts of TB patients in the border areas of Northern Thailand. Methods: A cross-sectional study with multi-stage random sampling was conducted in Chiang Rai Province. The study included 422 TB patients' household contacts aged 18 years or older who had available chest X-ray (CXR) results. A self-administered questionnaire was used to conduct the survey. Results: The participants' mean age was 42.93 years. Pearson correlation analysis showed that TB preventive behavior scores were significantly correlated with TB knowledge (r=0.397), perceived susceptibility (r=0.565), perceived severity (r=0.452), perceived benefits (r=0.581), self-efficacy (r=0.526), and cues to action (r=0.179). Binary logistic regression revealed that the modeled odds of having an abnormal CXR decreased by 30.0% for each 1-point score increase in preventive behavior (odds ratio, 0.70; 95% confidence interval, 0.61 to 0.79). Conclusions: HBM constructs were able to explain preventive behaviors among TB patients' household contacts. The HBM could be used in health promotion programs to improve TB preventive behaviors and avoid negative outcomes.

양궁지도자의 완벽주의 성향과 직무스트레스의 관계 (Relationship between Perfectionism and Job Stress of Archery Trainers)

  • 홍길동;임태희;고용주
    • 한국콘텐츠학회논문지
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    • 제8권10호
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    • pp.361-372
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    • 2008
  • 본 연구는 양궁지도자의 완벽주의 성향과 직무스트레스 요인의 관계를 규명하는데 그 목적이 있다. 연구 대상은 2007년도에 개최된 전국 중 고 양궁선수권대회에 참여한 양궁팀의 지도자 113명을 대상으로 목적적 표본 추출하였다. 측정도구는 Hewitt & Flett(1991)가 개발한 완벽주의 척도를 임태희(2005)가 한국적 문화와 정서에 맞도록 개발한 완벽주의 척도와 조만태(1998)가 개발한 직무스트레스 척도로 각각 5점 척도와 7점 척도로 평정하였다. 입력된 자료는 SPSS 13.0 for Window 프로그램을 활용하여 기술통계분석과 Pearson의 상관분석과 중다회귀분석을 실시하였다. 도출된 연구결과는 다음과 같다. 첫째, 양궁 지도자의완벽주의 성향은 개인완벽, 타인완벽, 사회완벽 요인 순으로, 직무스트레스는 직무여건스트레스, 시합스트레스, 직무부하스트레스, 지원체계스트레스, 대인관계스트레스 요인 순으로 높게 나타났다. 둘째, 양궁지도자의 완벽주의 성향 요인 중에서 개인완벽 요인은 직무여건스트레스, 시합스트레스, 직무부하스트레스와, 타인완벽 요인은 시합스트레스, 직무부하스트레스와 관계가 있는 것으로 나타났다. 셋째, 양궁지도자의 개인완벽주의 성향 요인은 직무여건스트레스에 직접적인 영향을 미치며, 개인완벽과 타인완벽주의 성향 요인은 시합스트레스와 직무부하스트레스에 직접적인 영향을 미치는 것으로 나타났다.

청주지역의 도심하천인 미호천에서 시공간적 수질변이 특성 및 유입지천의 영향 (Spatial and Temporal Variations of Water Quality in an Urban Miho Stream and Some Influences of the Tributaries on the Water Quality)

  • 김지일;최지웅;안광국
    • 한국환경과학회지
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    • 제23권3호
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    • pp.433-445
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    • 2014
  • The objective of study was to analyze seasonal and inter-annual patterns of water chemistry of Miho Stream watershed during 2004 - 2007 along with some influences of tributaries and summer monsoon on the stream water quality. For the study, eight physico-chemical parameters such as nitrogen, phosphorus, BOD, COD and chlorophyll-a (CHL) etc. were analyzed in relation to spatial and temporal variability of seven sampling sites of the mainstream and some tributaries in the watershed. In the upstream reach, Mean of BOD, COD and TP averaged 3.2 mg/L, 6.5 mg/L and $186{\mu}g/L$, respectively, indicating an eutrophic conditions as a III-rank in the stream water quality criteria from the Ministry of Environment, Korea(MEK). The eutrophic water was due to a combined effect of Chiljang tributary with high nutrients ($TP=844{\mu}g/L$, TN=8.087 mg/L) and the point sources from some wastewater treatment plants. In the meantime, BOD, TN, and TP in the downstream reach were about > 1.2-1.5 folds than the values of the midstream reaches. This was mainly attributed to effluents of nutrient rich-water (mean TN: 11.980 mg/L) from two tributaries of Musim Stream and Suknam Stream, which is directly influenced by nearby wastewater disposal plants. Seasonal analysis of water chemistry showed that summer monsoon rainfall was one of the important factors influencing the water quality, and water quality had a large spatial heterogeneity during the rainfall period. In the premonsoon, BOD in the downstream averaged $6.0{\pm}2.47mg/L$, which was 1.4-fold greater than the mean of upstream reach. Mean of CHL-a as an indicator of primary productivity in the water body, was > 2.2 - 2.9 fold in the downstream than in the upstream, and this was a result of the high phosphorus loading from the watershed. Overall, our data suggest that some nutrient controls in point-source tributary streams are required for efficient water quality management of Miho Stream.

지방부 간선도로 단속류 통행시간 추정을 위한 적정 집락간격 결정에 관한 연구 (A Study on the Optimal Aggregation Interval for Travel Time Estimation on the Rural Arterial Interrupted Traffic flow)

  • 임형석;이승환;이현재
    • 한국ITS학회 논문지
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    • 제3권2호
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    • pp.129-140
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    • 2004
  • 본 논문에서는 지방부 간선도로 단속류 구간(국도 42호선 양지$\~$용인구간 6km)의 통행시간정보에 관한 체계적인 수집 $\cdot$ 분석을 위해 현재 국도교통관리시스템(RTMS : Rural Trafc Management System)상에서 운영중인 차량 번호판 매칭방식 AVI 수집자료에 대한 신뢰성 검증 및 단속류 구간 통행시간 자료의 적정집락간격에 관한 연구가 수행되었다. 우선 AVI수집자료 신뢰성 검증을 위하여 번호판 매칭방식 AVI표본수집자료와 전수조사자료를 Kolmogorov-Smirnov 검증기법을 이용하여 분석한 결과 AVI 자료는 통과위주의 대표차로상에서 수집되는 관계로 전차로에 대한 수집자료와 교통특성에 차이가 있어 현재의 번호판 매칭방식 AW 표본수집자료를 통해 산출된 구간통행시간을 구간의 대표값으로 적용하는 문제는 추가 검토가 필요하다. 그리고 적정집락간격을 산출하기 위하여 통계적 추정 개념인 점추정과 구간추정을 적용하여 모형을 개발하여 적용한 결과 점추정기법이 구간추정기법보다 집락간격결정에 민감하고, 보다 정확한 적정집락간격 선정이 가능한 것으로 밝혀졌으며, 적정집락간격은 5분으로 산정되어 현재 적용되고 있는 5분 집락간격은 적정한 것으로 판단된다.

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Species Diversity Analysis of Mushrooms Collected in Mt. Chiak

  • Lee, Byung-Kook;Kim, Kyoung Su;Eom, Ki-Cheol;Seok, Soon-Ja
    • 한국균학회소식:학술대회논문집
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    • 한국균학회 2014년도 춘계학술대회 및 임시총회
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    • pp.19-19
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    • 2014
  • This study included the analysis of mushroom data collected from Mt. Chiak in Gangwon-do using various methods. Former studies of Korean mushrooms are limited by regional characters and there is less species diversity among the regions. This study tried to find a way for the forecast of mushroom distribution and appearance by indexes of species diversity. The indexes used in this study include the number of fungi (N), the number of species (S), similarity index (C), richness index (R1, R2), variety index (V1, V2), evenness index (E1, E2, E3, E4, E5), and dominance index (D1) to analyze variety of species diversity. Analyses of data of fungi using a multistage cluster sampling indicate that the average value of C for years was higher than the average value of C for areas. The mushrooms consisted of 208 species in 686 individuals in limited fungal collection from 2002 to 2003. One hundred thirty nine species in 393 individuals were collected in 2002, and 122 species 293 individuals were collected in 2003. The individuals collected in 2003 were smaller than 2002's individuals. Similarity, richness, and variety indexes' values of 2003 were reduced than 2002's values but dominance index of 2003 was increased than 2002's value. Generally the species diversity of the environment to evaluate the index of similarity, richness, and variety was a higher index; dominance index was lower than that of the surrounding environment, suggesting a good diversity. As a result, the occurrence of mushrooms in the surrounding environment and the various factors seem fell in 2002 compared to 2003. The majority genus of the limited fungal collection was Mycena genus in 63 individuals; the majority species was Laccaria laccata in 34 individuals. Ninety three species in 106 individuals were collected by the extended collection and the majority genus of the extended collection was Amanita genus in 17 individuals; the majority species was Amanita citrina (Schaeff.) Pers. which was found in 5 individuals. This demonstrates that periodical similarity's value was 0.159 is higher than special similarity's 0.119. This indicates that the probability of the appearance of same mushrooms in the same area in following year is higher than the probability of the appearance of same mushrooms in the surrounding area in same year. The value of coefficient of variation (CV), in which the amount of change is much or less by N is higher than the CV value by S. CV value of dominance index(D) was the highest r point among other indexes, and evenness index (E) was the lowest point among other indexes. The correlation matrix with 66 combinations between the indexes, the combinations with correlations was 46 combinations. These results revealed that indexes of R1, V2, and E1 were proper to represent species diversity of fungi based on the correlation matrix and the theory of statistical independence which means there is no or less mutual association. This research would contribute to the study about variable living creature by measuring method and in the future this would be used to figure out regulation about fungi with their correlation, values in ecosystem, develop improving new models about agricultural fungi species and numbers by investigating agricultural variable species.

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금호강의 상.하류간 이.화학적 수질구배 및 이에 따른 어류 길드영향 (Physico-chemical Water Quality Gradients Along the Main Axis of the Headwater-to-Downstream of Geumho River and Their Influences on Fish Guilds)

  • 김용휘;한정호;안광국
    • 한국물환경학회지
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    • 제28권4호
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    • pp.561-573
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    • 2012
  • The object of this study was to analyze long-term water quality gradients during 1992-2008 at six sites of Geumho River and near-by two sites of Nakdong River and their influences on fish trophic guilds and tolerance guilds along with ecological health. Water quality including biological oxygen demand (BOD), chemical oxygen demand (COD), conductivity, total phosphorus (TP), total nitrogen (TN), and total suspended solids (TSS) varied largely depending on the sampling locations and seasons. Values of ambient BOD, COD, TP, and TN were greater in the downstream than in the upstream reach, and seasonal and interannual variabilities were also higher in the downstreams. This phenomenon was evident due to a dilution by the Asian monsoon rainfall during the monsoon. These outcomes indicate that point sources near the downstream are important for the chemical conditions, but also seasonal stream runoff was considered as an important factor regulating the chemical conditions. Conductivity decreased rapidly during the summer due to ionic dilution, and nutrients (N, P), BOD, COD had an inverse function of seasonal precipitation. Based on the water quality, we selected two sites (control site = $C_s$ vs. impacted site = $I_s$) for impact analysis of water chemistry on fish community and trophic/tolerant guilds. Fish guild analysis showed that species diversity was higher in the headwater stream ($C_s$) than the impacted downstream ($I_s$), and that the proportion of tolerant and omnivore species were greater in the impacted site of downstream. Comparisons of water quality between Geumho River and Nakdong River indicated that Geumho River was considered as a point source which degradated water quality to the Nakdong River. Overall, chemical water quality and fish guild analysis suggest that even if current chemical quality got better after 1996 due to continuous constructions of wastewater disposal plants near the downstreams, fish compositions of tolerant and omnivores were still dominated the community. Thus, biological restoration based on ecological health is required for the ecosystem conservation.

부산지역 거주 노인의 인지기능장애 및 치매 유병률 (Prevalence Rate of Cognitive Impairment and Dementia Among the Elderly in Busan)

  • 김정순;이수일;정영인;황인경;이봉숙;김민정;초의수;전진호;정인숙
    • Journal of Preventive Medicine and Public Health
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    • 제36권1호
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    • pp.63-70
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    • 2003
  • Objectives : To investigate the prevalence of cognitive impairment and dementia in elderly people, aged 65 or above, residing in Busan Metropolitan City. Methods : Total of 1,101 old people, aged 65 or above, living in Busan as of December 31, 2001 were selected using stratified three-stage cluster sampling. Cognitive impairment was determined from the MMSE-K score, and dementia confirmed from five psychometric measures and the Barthel index. The crude prevalence, sex-age adjusted for the Korean population, were obtained. Results : With the cut-off point for cognitive impairment was set at 24 points, or below, on the MMSE-K scale, the crude rate of cognitive impairment was 29.3% (15.7% for men and 37.5% for women), and the sex-age adjusted prevalence was 30.5% (17.5% for men and 37.0% for women). When the cut-off point for cognitive impairment was set at 20 points, or below, on the MMSE-K scale, the crude rate of cognitive impairments were 10.0% (4.1% for men and 13.5% for women), and 10.6% (4.7% for men and 13.1% for women), respectively. The crude dementia, and the sex-age adjusted rates were 7.4% (2.4% for men and 10.5% for women), and 8.0% (2.7% for men and 10.0% for women), respectively. Conclusions : The prevalence of dementia in this study was somewhat lower than that reported by other domestic and foreign studies. Our results related to the difference in time and space, diagnostic tools, response rates, and distribution of male and female subjects, etc.

호수 퇴적물의 호기 및 혐기조건에서의 용출 특성에 대한 연구 (A Study on Release Characteristics of Lake Sediments under Oxic and Anoxic Conditions)

  • 윤미해;현준택;허남수;권성현;조대철
    • 대한환경공학회지
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    • 제29권9호
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    • pp.1003-1012
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    • 2007
  • 호수 퇴적물의 용출로 인한 수질오염을 예측하고 퇴적 위치에 따른 용출 특성을 파악하기 위해 환경 조건에 따른 용출 차이를 분석하였다. 분석 항목으로는 질소계열, 인계열, COD를 분석하였으며, 모든 시료의 분석 방법은 호수 내부수의 염도가$(Cl^-)$ 2,000 ppm 이상이므로 해수 수질공정 시험법에 준하여 실시하였다. COD는 혐기조일 경우 A지점에서 C지점으로 갈수록 용출율이 증가한 반면, 호기조일 경우 증 감의 경향성이 없었다. $NH_3$-N의 호기조일 경우 A지점에서 C지점으로 갈수록 용출율이 감소하였고, 반대로 질산화 작용으로 인해 $NO_3$-N과 T-N은 A지점에서 C지점으로 갈수록 용출율이 증가하였다. $NH_3$-N, $NO_3$-N의 혐기조는 A지점에서 C지점으로 갈수록 용출율이 증가하였으나 탈질화 작용으로 인하여 T-N의 용출율은 감소하는 경향을 보였다. $PO_4$-P, T-P의 경우 호기조에서 B지점의 용출율이 가장 낮았으며, 이는 용존 산소의 함량이 많아 무기물이 산화되면서 인의 용출이 억제된 것으로 판단된다. $PO_4$-P의 혐기조일 경우 A지점부터 C지점의 용출율이 서로 유사하였다. COD와 $NO_3$-N의 경우 혐기조보다 호기조에서 용출율이 높았으며, 그 외의 항목에서는 호기조보다 혐기조에서 용출율이 높았다.