• Title/Summary/Keyword: point sampling

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

  • Yohan Park;Wonpil Park;Seungki Kim
    • Journal of Auto-vehicle Safety Association
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    • v.15 no.4
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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
    • Journal of Korean Academy of Nursing
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    • v.53 no.6
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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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    • v.57 no.3
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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.

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

  • Hong, Kil-Dong;Lim, Tae-Hui;Ko, Young-Ju
    • The Journal of the Korea Contents Association
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    • v.8 no.10
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    • pp.361-372
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    • 2008
  • The purpose of this study was to verify the relationship between perfectionism and job stress of archery trainers. Participants of this study were 113 archery trainers who worked at the middle and high school's archery teams. Some of the archery trainers who participated in korea archery championship for junior in 2007 were selected using the purposive sampling method. The questionnaire was Multidimensional Perfectionism Scale developed by Hewitt and Flett(1991) which was revised by Lim(2005) into Korean and The Job Stress Scale developed by Jo(1998). Responses were made on 5-point and 7-point scale. The statistical methods for the analysis of this study were Pearson's correlation and multiple regression analysis. The results of this study were as follows. First, there was self perfectionism, person perfectionism, social perfectionism highly on the perfectionism of archery trainers and job condition stress, game stress, job load stress, support system stress, interpersonal relation stress highly on the job stress. Second, there was statistical significant relation between the job condition stress, game stress, job load stress and self perfectionism, between the game stress, job load stress and person perfectionism. Third, self perfectionism affect on job condition stress and self and person perfectionism affect on game stress, job load stress.

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

  • Kim, Ji-Il;Choi, Ji-Woong;An, Kwang-Guk
    • Journal of Environmental Science International
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    • v.23 no.3
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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.

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

  • Lim Houng-Seak;Lee Seung-Hwan;Lee Hyun-Jae
    • The Journal of The Korea Institute of Intelligent Transport Systems
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    • v.3 no.2 s.5
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    • pp.129-140
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    • 2004
  • In this paper, we conduct the research about optimal aggregation interval of travel time data on interrupted traffic flow and verify the reliability of AVI collected data by using car plate matching method in RTMS for systematic collection and analysis of link travel time data on interrupted traffic flow rural arterial. We perform Kolmosorov-Smirnov test on AVT collected sample data and on entire population data, and conclude that the sample data does not represent pure random sampling and hence includes sample collection error. We suggest that additional review is necessary to investigate the effectiveness of AVI collected sample data as link representative data. We also develop statistical model by applying two estimation techniques namely point estimation and interval estimation for calculating optimal aggregation interval. We have implemented our model and determine that point estimate is preferable over interval estimate for exactly selecting and deciding optimal aggregation interval. Our final conclusion is that 5-minute aggregation interval is optimal to estimate travel time in RTMS, as is currently being used our investigation is based on AVI data collected from Yang-ji to Yong-in $42^{nd}$ National road.

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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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    • 2014.05a
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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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Physico-chemical Water Quality Gradients Along the Main Axis of the Headwater-to-Downstream of Geumho River and Their Influences on Fish Guilds (금호강의 상.하류간 이.화학적 수질구배 및 이에 따른 어류 길드영향)

  • Kim, Young-Hui;Han, Jeong-Ho;An, Kwang-Guk
    • Journal of Korean Society on Water Environment
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    • v.28 no.4
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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.

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

  • Kim, Jung-Soon;Lee, Su-Ill;Chung, Young-In;Hwang, In-Kyung;Yih, Bong-Sook;Kim, Min-Jeong;Cho, Eu-Soo;Chun, Jin-Ho;Jeong, Ihn-Sook
    • Journal of Preventive Medicine and Public Health
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    • v.36 no.1
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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.

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

  • Yoon, Mi-Hae;Hyun, Jun-Taek;Huh, Nam-Soo;Kwon, Sung-Hyun;Cho, Dae-Chul
    • Journal of Korean Society of Environmental Engineers
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    • v.29 no.9
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    • pp.1003-1012
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    • 2007
  • In this study, we analyzed the release differences for some critical pollution compounds according to the surrounding conditions in order to predict water quality due to the sedimental releases and the release characteristics at different sedimental locations in Lake Leewon, in Tae-An area. COD, nitrogens and phosphates were analyzed using the standard methods for water quality, based on high chloride ion concentration(greater than 2,000 ppm). For COD, the release rate increased in the anoxic basin but almost the same in the oxic basin. For $NH_3$-N, the release rate decreased in the oxic basin as you go A through C point meanwhile, for $NO_3$-N and T-N, the tendency was reversed because of nitrification of them. In the anoxic basin, the release rates of $NH_3$-N and $NO_3$-N went up with A through C path. However, the release rate of T-N was found to decrease. Also, for $PO_4$-P and T-P, the release rates in the oxic basin were lowest at B point mainly because the phosphates were at less released in the highly $O_2$ concentrated environment. In the anoxic reactor, $PO_4$-P was released similarly regardless of the sampling points. In summary, the release rates in the oxic reactor were greater than those in the anoxic reactor for COD and $NO_3$-N. For the other components, the anoxic basin generated the higher release rates.