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A Study on the Color Perception of University Students (대학생의 선지각에 관한 연구)

  • 안옥희;박숙현;이정옥
    • The Proceedings of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.7 no.4
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    • pp.19-25
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    • 1993
  • The purpose of this study was to investigate the scope of color perception for Korean standard color. 99 male and 126 female university students were selected as the random sample. Color perception was made with the naked eyes. Minolta Chroma Meter CR 300 was used for physical measurement of the color. The results were as follows, 1) Color perception was classified into four large groups: simple group includes Red, Yellow Red, Pale Red Yellow, Yellow, X( -axis)group includes Pale Yellow Red, Pale Green Yellow, Green Yellow, Purple, Pale Red Purple, Y( -axis)group includes Pale Blue Green, Blue Green, Pale Green Blue, Blue, Pale Ptuple Blue, complex group includes Pale Yellow Green, Green, Purple Blue, Pale Blue Purple, Red Purple, Pale Purple Red. 2) There is little difference between the values of standard color and mean percept color for Blue, Yellow, Pale Green Yellow, Green Yellow, Pale Yellow Green, Green, Pale Blue Green, Blue Green, Purple, while big difference for Blue, Pale Green Blue, Pale Red Purple, Pale Purple Red. 3) As for as sex was concerned, female is more accurate than male in color perception.

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A Global Self-Position Localization in Wide Environments Using Gradual RANSAC Method (점진적 RANSAC 방법을 이용한 넓은 환경에서의 대역적 자기 위치 추정)

  • Jung, Nam-Chae
    • Journal of the Institute of Convergence Signal Processing
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    • v.11 no.4
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    • pp.345-353
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    • 2010
  • A general solution in global self-position location of robot is to generate multiple hypothesis in self-position of robot, which is to look for the most positive self-position by evaluating each hypothesis based on features of observed landmark. Markov Localization(ML) or Monte Carlo Localization(MCL) to be the existing typical method is to evaluate all pairs of landmark features and generated hypotheses, it can be said to be an optimal method in sufficiently calculating resources. But calculating quantities was proportional to the number of pairs to evaluate in general, so calculating quantities was piled up in wide environments in the presence of multiple pairs if using these methods. First of all, the positive and promising pairs is located and evaluated to solve this problem in this paper, and the newly locating method to make effective use of calculating time is proposed. As the basic method, it is used both RANSAC(RANdom SAmple Consensus) algorithm and preemption scheme to be efficiency method of RANSAC algorithm. The calculating quantity on each observation of robot can be suppressed below a certain values in the proposed method, and the high location performance can be determined by an experimental on verification.

AUTOMATIC PRECISION CORRECTION OF SATELLITE IMAGES

  • Im, Yong-Jo;Kim, Tae-Jung
    • Proceedings of the KSRS Conference
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    • 2002.10a
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    • pp.40-44
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    • 2002
  • Precision correction is the process of geometrically aligning images to a reference coordinate system using GCPs(Ground Control Points). Many applications of remote sensing data, such as change detection, mapping and environmental monitoring, rely on the accuracy of precision correction. However it is a very time consuming and laborious process. It requires GCP collection, the identification of image points and their corresponding reference coordinates. At typical satellite ground stations, GCP collection requires most of man-powers in processing satellite images. A method of automatic registration of satellite images is demanding. In this paper, we propose a new algorithm for automatic precision correction by GCP chips and RANSAC(Random Sample Consensus). The algorithm is divided into two major steps. The first one is the automated generation of ground control points. An automated stereo matching based on normalized cross correlation will be used. We have improved the accuracy of stereo matching by determining the size and shape of match windows according to incidence angle and scene orientation from ancillary data. The second one is the robust estimation of mapping function from control points. We used the RANSAC algorithm for this step and effectively removed the outliers of matching results. We carried out experiments with SPOT images over three test sites which were taken at different time and look-angle with each other. Left image was used to select UP chipsets and right image to match against GCP chipsets and perform automatic registration. In result, we could show that our approach of automated matching and robust estimation worked well for automated registration.

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Effect of Experimental Layout on Model Selection under Variance Components Models: A Simulation Study (분산성분모형에서 요인의 배치구조가 모형선택법에 미치는 영향에 대한 실험연구)

  • Lee, Yonghee
    • The Korean Journal of Applied Statistics
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    • v.28 no.5
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    • pp.1035-1046
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    • 2015
  • Variance components models incorporate various random factors in the form of linear models. There are two experimental Layouts for the classification of factors under variance components models: nested classification and crossed classification. We consider two-way variance components models and investigate the effect of experimental Layout on the performance of model selection criteria AIC and BIC. The effect of experimental Layout is studied through a simulation study with various combinations of parameters in a systematic fashion. The simulation study shows differences in performance of model selection methods between the two classification. There is a particular tendency to prefer the smaller model than the true model when the variance component of a nested factor becomes relatively larger than a nesting factor that is persistent even when the sample size is not small.

The Factorial Structure and Psychometric Properties of the Persian Effort-Reward Imbalance Questionnaire

  • Babamiri, Mohammad;Siegrist, Johannes;Zemestani, Mehdi
    • Safety and Health at Work
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    • v.9 no.3
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    • pp.334-338
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    • 2018
  • Background: With global changes in the current state of work and employment, the role of health-adverse psychosocial work environments has received increasing attention in developed as well as in rapidly developing countries. Thus, there is a need to apply valid measurement tools for monitoring and preventive purposes. This study aims to examine the factorial structure and psychometric properties of the Persian version of the effort-reward imbalance (ERI) questionnaire, assessing one of the internationally leading concepts of stressful work. Methods: This descriptive cross-sectional study of a random sample of 202 white collar employees in an industrial company in Iran analyzes the ERI scales by exploratory and confirmatory factor analysis. Moreover, aspects of construct and criterion validity are tested. To this end, correlations of ERI scales with subscales of organizational injustice, a complementary work stress model, and also the correlations of ERI scales with a questionnaire assessing psychosomatic symptoms are performed. Results: Internal consistency of the three ERI scales was satisfactoryy (Cronbach ${\alpha}$ effort: 0.76, reward: 0.79, overcommitment: 0.75). Fit indices of confirmatory factor analsis pointed to an adequate representation of the theoretical construct (e.g., adjusted goodness of fit index (AGFI): 0.73, goodness of fit index (GFI): 0.78). Negative correlations with subscales of organizational injustice supported the notion of construct validity of the ERI scales, and positive correlations of ERI scales with psychosomatic symptoms indicated preliminary criterion validity. Conclusion: The Persian version of the ERI questionnaire has acceptable psychometric properties and can be used as a valid instrument in research on this topic.

Cost analysis of hypertension screening program (고혈압 건강진단의 비용분석)

  • Park, Eun-Cheol;Yu, Seung-Hum
    • Journal of Preventive Medicine and Public Health
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    • v.22 no.3 s.27
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    • pp.380-388
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    • 1989
  • To evaluate the costs of the hypertension screening program of the Korea Medical Insurance Corporation, the records of the screening examinations were used. The sample size was 49,983 of the 906,554 people insured by the Corporation and was obtained by two-stage stratification random sampling. The alternatives for efficiency of the screening program, which were divided into three categories : modification of the screening test package, application of other hypertension diagnostic criteria, and selective approach of tested groups by age, were evaluated according to the cost per patient detected. The results of this study were as follows In the hypertension screening system, the cost per patient detected was Won 30,883. The most nonsensitive test for hypertension detection was ophthalmoscopy, which was examined during the second stage of screening. If the ophthalmoscope examination was excluded, olny one person was not detected, which was 0.2% of detected persons, and the cost per patient detected decreased to Won 28,098. The most efficient modification of the screening test package was measurement of blood pressure through the first and second stages of screening. The cost per patient detected by this modification was Won 24,408. The application of other diagnostic critera, which were more restricted criteria, increased the cost per patient detected by 3.7%-6.7%. The cost per patient detected were Won 170,582 for persons less than 39 years old, Won 20,032 for persons 40 to 59 years old, and Won 8,675 for persons 60 years old and over. In conclusion, the best alternative suggested with respect to efficiency and practical application excluded the ophthalmoscope examination of second stage screening and restricted the target population to persons greater than 40 years old. The application of this alternative decreased 54.9% of the screening costs and the cost per patient detected was Won 15,222. This study was limited in that measurement of effectivenes was not of the ultimate goal of screening, which is decreasing morbidity and mortality, but was of disease detection as the short-term objective.

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Subjective Satisfaction with Medical Care among Older People: Comprehensiveness, General Satisfaction and Accessibility (노인 의료이용의 주관적 만족도: 포괄성, 전반적인 만족도, 접근성을 중심으로)

  • Kim, Hwa-Joon;Koh, Young;Chun, Eun-Jeong;Jang, Soong-Nang;Kim, Chang-Yup
    • Journal of Preventive Medicine and Public Health
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    • v.42 no.1
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    • pp.35-41
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    • 2009
  • Objectives : The changing population age structure and rapidly increasing medical costs make providing high-quality, effective medical care for the elderly a challenge. This study assessed the satisfaction with medical care in terms of comprehensiveness, general satisfaction, and accessibility among community-dwelling Korean elders. Methods : Data were obtained from a nationwide representative sample of the older adults(aged 65 years old or older) living in the community, who participated in a 2006 telephone survey conducted using random digit dialing(n=881). General satisfaction, comprehensiveness and accessibility were measured using a 10-item satisfaction survey questionnaire. Descriptive analysis was used to assess the distribution of each of three components of subjective satisfaction. Analysis of covariance(ANCOVA) was used to examine the association of each of the three components with socioeconomic variables. Results : Comprehensiveness and general satisfaction were low among older people with a high socioeconomic status. Accessibility was evaluated as low among older people of low socioeconomic status, those living in rural areas and those who were medical aid beneficiaries. Conclusions : Urgent interventions should be considered in order to improve accessibility to medical care for elders of low socioeconomic status and those living in rural communities. Given the rapid aging of the population, we need to develop a monitoring system to improve the quality of geriatric care.

Ecological Analysis of Food Behavior and Life-Styles Affecting the Prevalence of Depression in Korea (한국인의 우울상태에 따른 식행동, 영양 섭취 상태 및 생활습성에 관한 생태학적 분석)

  • 김정현
    • Journal of Nutrition and Health
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    • v.26 no.9
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    • pp.1129-1137
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    • 1993
  • This study was carried out to analyze the effects of dietary and life-style factors on the prevalence of depression in Korea. Epidemiologic data from a nation-wide sample of 2,000 adults who were selected with the stratified random sampling method in Korea were interviewed by trained interviewers. Data were presented on the CES-D, a 20-items self-report depression symptom scale developed by the Center for Epidemiologic Studies in U.S.A. The prevalence of depression among all the respondents was 13.5%, with 13.1% in urban samples and 15.5% in rural samples. The prevalence was higher in females(15.3%) than in males(11.7%). There were highly marked differences in the prevalence of depression by sex(p<0.05), age(p<0.0001), education(p<0.001) and income(p<0.01). Respondents of 60 years and over group, the less educated group(below elementary school graduated), and the less income group(less than 400,000 won/month) reported the highest rate of depression. However subjects' occupation and residence had little relation with the prevalence of depression. Drinking and smoking habit appeared to be highly associated with depression in females(p<0.0001) but not in males. The prevalence of depression and eating behavior were highly related(p<0.005). Male respondents below 20 years, 20-29, and 60 years and over depressed group reported significantly lower energy and protein intakes compared to that of the normal group. However, in the female respondents 20-29 years and 60 years and over depressed groups showed the significantly lower energy and protein intakes compared to those of the normal groups(p<0.05), it can be concluded that the various ecological factors such as epidemiological, dietary, and health factors may affect the prevalence of depression among Korean.

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Adoption and Implementation of Tobacco Control Policies in Schools in India: Results of the Bihar School Teachers Study

  • Mathur, N;Pednekar, MS;Sorensen, GS;Nagler, EM;Stoddard, AM;Lando, HA;Aghi, MB;Sinha, DN;Gupta, PC
    • Asian Pacific Journal of Cancer Prevention
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    • v.17 no.6
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    • pp.2821-2826
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    • 2016
  • Implementation of no tobacco policies in schools is associated with lower tobacco use among teachers and students. In this study we assessed the extent that a school-based intervention for teachers resulted in adoption and implementation of tobacco control policies. From a random sample of government schools ($8^{th}-10^{th}$), 72 were randomized into intervention and control conditions. Intervention included health education programs for teachers and support for tobacco control policy implementation. Adoption and implementation of policies were assessed at baseline and immediately after intervention. All 36 intervention and one control school adopted a tobacco-control policy. Higher enforcement of tobacco-control policy was at post intervention (OR=3.26; CI: 2.35, 4.54) compared to baseline in intervention schools. Some 64% of intervention and 28% control schools showed "improvement" in policy implementation. Adoption and implementation of no tobacco policies was positively impacted by intervention. This study provides support for scaling up of school-based tobacco control interventions to promote school tobacco control policies.

A Study on a Combination Model Development for Counterfire Operation with Heterogeneous Weapon System (대화력전에 대한 이종 무기체계의 조합모델개발 연구)

  • Kim, Hanyoung;Kim, Seungcheon;Ro, Kwanghyun
    • Journal of the Institute of Electronics and Information Engineers
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    • v.53 no.2
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    • pp.62-69
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    • 2016
  • This paper proposes to select Measure of Performance(MOP) for object attainment in the counterfire operation and deduce the reasonable combination of blue force's hitting resources satisfying MOP's optimal value and regression equation for the object achievement time. Also, in the study-methodological perspective, a series of procedures for drawing the regression equation from the real world is presented. Firstly the model was made by simplifying the weapon-system information of red force and blue force, then the time for object attainment was derived from its simulation. Simulating the model for the counterfire operation was divided into three phases-detection, decision and hitting. The probability method by applying the random numbers were used for detection, fixed constant numbers for decision and hitting. The simulation was repeatedly performed to get the minimum time for the object attainment against the fixed enemy, and it was estimated as the optimal value of simulation. From this result, the optimum combination of blue force's weapon system against the red force and finally, the regression equation were obtained by using the response surface analyzing method in MINITAB. Thereafter this equation was completely verified by using 'the 2-sample t-test.' As a result, the regression equation is suitable.