• Title/Summary/Keyword: 인과성 검정

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Study on Function Improvement and Application of D2MS (PDA 유량측정 관리시스템의 기능 개선 및 활용성 검토)

  • Lee, Kyoung-Do;Jung, Seung-Kwon;Kim, Nam-Il
    • Proceedings of the Korea Water Resources Association Conference
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    • 2006.05a
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    • pp.903-907
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    • 2006
  • 수위, 우량, 유량, 유사량 등 수문자료 중에서 유량자료는 가장 많은 쓰임새를 갖고 있음에도 불구하고 신뢰도가 낮은 이유로 인해 많은 문제점을 안고 있는 것이 현실이다. 이렇게 유량측정자료의 신뢰도가 낮은 이유는 크게 5가지로 들 수 있는데 1)측정 수행자의 잦은 교체 등에 따른 조사역량 부족, 2)수행자별 유량측정 및 분석방법 상이, 3)장비의 유속검정 등 관리미흡 및 성능 저하, 4)유량측정 상당시간 경과 후 유량측정성과 정리로 오류 수정 곤란, 5)유량측정성과의 체계적인 관리 미흡 등이다. 이러한 문제점을 개선하고 현장에서의 유량측정 신뢰도를 향상시키기 위하여 (주)웹솔루스에서는 PDA를 이용한 유량측정 관리시스템을 개발하였으며 기존의 한국수자원공사에 국한된 기능을 건설교통부 한국건설기술연구원에서 활용이 가능하도록 프라이스컵을 이용한 유량측정이 가능하도록 유량측정 관리 시스템의 기능을 개선하였다. 현재 이 시스템 C/S 기반 및 웹 기반으로 개발되었으며, 2003년부터 2005년까지의 주요 댐 지점에서의 성과를 바탕으로 그 활용성을 검토하였다. 본 시스템을 기반으로 측정된 자료들은 사용자가 보유하고 있는 서버에 실시간으로 저장이 되며, 현 2006년에는 한국수자원공사에서 운영하고 있는 13개의 댐과 1개의 국가 하천에 대하여 총 59개의 관측지점에서 활용되고 있고 있다. 본 시스템 도입을 통해 유량측정성과가 체계적으로 관리되고 있으며, 향후 시스템에 대한 지속적인 유지 관리가 이루어진다면 오랜 기간에 걸쳐 축적된 많은 양의 유량자료는 수자원관리에 큰 역할을 수행할 수 있을 것으로 판단된다. 입력자료로 변환하도록 하는 자료 동화 기능, CE-QUAL W2 모형을 수행하는 기능 및 결과자료를 분석하는 기능으로 구성되어 있으며, 각 기능을 선택하면 해당 화면으로 GUI가 전환된다. 따라서 다량의 측정자료의 신뢰성을 유지하고 이를 모형의 입력자료로 활용하는 일련의 과정을 시스템화하기 때문에 자료의 이상적 유지 관리가 이루어지며 복잡한 2차원 수질해석 모형을 수월하게 운영할 수 있는 시스템으로 개발하였다.제외하면, 부자측정 방법에 의한 유량산정시 가장 큰 오차원인은 홍수시 측정된 유속측선의 위치와 홍수 전후로 측정된 횡단면상의 위치가 일치하지 않는 점과, 대부분 두 측정 구간의 평균값을 대푯값으로 사용한다는 점이다. 본 연구는 다년간의 유량 측정 및 검증 경험과 자료를 토대로 현장에서 부자를 이용하여 측정된 측정성과를 정확도 높은 유량자료로 산정하는데 있어서의 문제점을 도출하고, 이로 인해 발생하는 오차를 추정하여 그 개선방안을 제시해 보고자한다. 더불어 보다 정확한 유량 산정을 위한 기준과 범주를 제시하고자 한다.리적 특성을 잘 반영하며, 도시지역의 복잡한 배수시스템 해석모형과 지표범람 모형을 통합한 모형 개발로 인해 더욱 정교한 도시지역에서의 홍수 범람 해석을 실시할 수 있을 것으로 판단된다. 본 모형의 개발로 침수상황의 시간별 진행과정을 분석함으로써 도시홍수에 대한 침수위험 지점 파악 및 주민대피지도 구축 등에 활용될 수 있을 것으로 판단된다. 있을 것으로 판단되었다.4일간의 기상변화가 자발성 기흉 발생에 영향을 미친다고 추론할 수 있었다. 향후 본 연구에서 추론된 기상변화와 기흉 발생과의 인과관

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An Evaluation Model on Supply Factors of Urban Park (도시공원의 공급인자 평가모형)

  • Chang, Byung-Moon
    • Journal of the Korean Institute of Landscape Architecture
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    • v.38 no.1
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    • pp.1-11
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    • 2010
  • The purpose of this paper is to evaluate supply factors of urban parks to answer the research question: What are the causal effects of supply factors of urban parks on visitor satisfaction? After reviewing the literature and the Korean park planning process, we constructed a conceptual framework and have formulated the hypothesis of this research. We had obtained data through a questionnaire, which surveyed 452 visitors at 8 urban parks in Daegu Metropolitan City in 2008, based on a stratified sampling method. After the elimination of 96 unsuitable samples, we have analyzed the data using descriptive statistical methods, Pearson's correlation analysis and a path analysis method. We have found that: 1) While the direct and indirect effect of accessibility(ACC) on visitor satisfaction(VS) turned out to be 0.184 and 0.220, respectively, the indirect effect of information(IFM) and promotion(PRM) on VS turned out to be 0.101 and 0.177, respectively. 2) While the direct and indirect effect of service(SVR) on VS turned out to be 0.130 and 0.236, respectively, the direct effect of ACC turned out to be 0.698. 3) While the direct effect of ACC, SVR and attraction(ATT) on VS turned out to be 0.184, 0.130 and 0.698, respectively, composing 67.96% of causal effect, the indirect effect of ACC, IFM, PRM and SVR on VS turned out to be 0.220, 0.101, 0.177 and 0.236, respectively, composing 42.04% of causal effect. 4) The magnitude of causal effect of supply factors on VS turned out to be ATT(39.98%), ACC(23.14%), SVR(20.96%), PRM(10.14%) and IFM(5.78%) in order, and 5) the causal effect of external supply factors of ACC, IFM and PRM compose 39.06% of the causal effect while that of the internal supply factors of SVR and ATT is 69.94%. The research results suggest that: 1) Planning for park marketing strategy and remedial directions for existing urban parks, in order to increase visitor satisfaction, be focused on IFM and PRM, especially. 2) The research approach and path analysis method adopted by this research be valid and highly useful for planning and evaluation of other recreation areas. It is recommended that: 1) Structural Equation Model on supply factors of urban parks be established in the future. 2) Evaluation of supply factors by type of urban park be performed.

A study on the economic performance measurement model of industrial safety design (산업안전디자인의 경제적 성과측정 모델 연구)

  • Jinho, Ahn
    • Journal of Service Research and Studies
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    • v.13 no.1
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    • pp.176-185
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    • 2023
  • This study is a study to develop a model to measure the economic performance when introducing industrial safety design, which is emerging as a necessity for industrial accident prevention measures due to the increase in the industrial site nursing accident rate and the enforcement of the Serious Accident Punishment Act. To this end, studies on the concept of industrial safety management and industrial safety design and economic performance measurement in the field of industrial safety were conducted in terms of theoretical background. Based on the theoretical background, opinions on drafts of related indicators were collected through user opinion surveys, and focus group interviews and Delphi techniques were conducted with experts, and research was conducted to advance the model. In order to secure objectivity, the causal relationship between the introduction of industrial safety design, cost reduction effect, and sales increase effect was tested through regression analysis. After going through these steps, two models of economic performance measurement of industrial safety design were finally developed: a model based on the first-stage disaster loss cost reduction effect and a second-stage sales increase effect. In order to be applied to actual industrial sites, it should be able to be presented as a standard for the degree of service level agreement of industrial safety design beyond a simple checklist.

Interdependence of the Asia-Pacific Emerging Equity Markets (아시아-태평양지역 국가들의 상호의존성)

  • Moon, Gyu-Hyun;Hong, Chung-Hyo
    • The Korean Journal of Financial Management
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    • v.20 no.2
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    • pp.151-180
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    • 2003
  • We examine the interdependence of the major Asia-Pacific stock markets including S&P 500, FTSE 100, Kualar Lumpur Composite, Straits Times, Hang Seng, NIKKEI 225 and KOSPI 200 from October 4, 1995 to March 31,2000. The analysis employs the vector-auto-regression, Granger causality, impulse response function and variance decomposition using daily returns on the national stock market indices. The findings in this paper indicate that the volatilities of all countries has grown after IMF crisis, while there is no significance in cointegration test of both total period and sub-periods. This result implies that investors are able to get abnormal returns by investment diversification according to the portfolio theory. We find that while the effect from NIKKEI 225 to others is relatively weak, the interdependence from S&P 500 to other countries is strong. Also we find that the strong effect from Straits Times to Hang Seng exists. This study suggests that there is slight feedback relation between KOSPI 200 and Kualar Lumpur Composite, Straits Times, Hang Seng stock market.

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Effects of Depression on the Rehabilitation Motivation of Middle-Aged Stroke Patients - Focused on the Mediating Effects of Resilience (뇌졸중 중년 환자의 우울이 재활동기에 미치는 영향 - 극복력의 매개효과 중심으로)

  • Oh, Soo-Yong;Hwang, Seon-Young
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.18 no.4
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    • pp.58-66
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    • 2017
  • This study was a descriptive correlational study investigating the mediating effects of resilience in the relationship between depression and rehabilitation motivation in middle-aged stroke patients. There was a total of 185 middle-aged patients aged 40 to 64 years, who were diagnosed with stroke at a university hospital and rehabilitated at three local hospitals located in S city and four hospitals in U city. The data were collected using a self-reported questionnaire between the 1st and 31st of December in 2016. The data were analyzed using t-test, ANOVA, Pearson's correlation coefficient, and step-wise causal method using SPSS/WIN 22.0 statistical program. To test the statistical significance of the mediation effect, PROCESS and bootstrapping were used. The mean age of the subjects were $56.26{\pm}6.37$ years. There were 70.3% male subjects, an average depression level was $21.21{\pm}7.09$, an average resilience was $25.52{\pm}9.63$, and rehabilitation motivation was $47.44{\pm}5.87$. Depression was negatively related to resilience and rehabilitation motivation. However, resilience and rehabilitation motivation have a static correlation. These results confirmed that resilience appears to be a complete mediating effect in the relationship between depression and rehabilitation motivation. Therefore, it is important to develop a resilience enhancement program to improve the motivation of rehabilitation for stroke patients.

The Level of Diabetes Management of Agriculture, Forestry, and Fishery Workers (농림어업인의 당뇨병 관리 수준)

  • Oh, Gyung-Jae;Lee, Young-Hoon
    • Journal of agricultural medicine and community health
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    • v.42 no.3
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    • pp.119-131
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    • 2017
  • Objectives: The purpose of this study was to compare the diabetic management indicators between agriculture, forestry, and fishery workers (AFF) and other occupational adults (non-AFF) in community-dwelling diabetes. Methods: The study population consisted of 22,127 diabetic population ${\geq}19years$ who participated in the 2015 Community Health Survey. Chi-square test and logistic regression analysis was used to compare the diabetic management indicators between AFF and non-AFF. Socioeconomic characteristics such as age, gender, education level, monthly household income, National Basic Livelihood Security status, and marital status was sequentially adjusted. Results: Among total diabetic population, 3,712 people (16.8%) was AFF and 18,415 people (83.2%) was non-AFF. The fully-adjusted odds ratio [OR] (95% confidence interval [CI]) of current non-medical treatment (0.72, 0.66-0.79), measurement of hemoglobin A1c (0.61, 0.55-0.67), screening for diabetic retinopathy (0.76, 0.70-0.83), screening for diabetic nephropathy (0.75, 0.70-0.81), non-alcoholic or moderate drinking (0.70, 0.64-0.78), nutrition label reading (0.83, 0.71-0.98), low salt preference (0.85, 0.78-0.93), dental examination (0.60, 0.54-0.66), scaling experience (0.84, 0.77-0.93), regular toothbrushing (0.66, 0.58-0.76), and diabetes management education (0.84, 0.77-0.92) was significantly lower in AFF compared to non-AFF. In contrast, the fully-adjusted OR (95% CI) of AFF's low stress level (1.39, 1.26-1.52) and adequate sleep duration (1.22, 1.13-1.32) was significantly higher than non-AFF, which are better indicators of diabetic management in AFF. Conclusions: Overall, the level of diabetes management of AFF was not as good as that of non-AFF. In order to improve the level of diabetes management of AFF, a delicate diabetes intervention strategy considering the occupational characteristics of AFF will be needed.

A Structural Relation Among Self-Efficacy, Self-Esteem and Life Satisfaction of Highly Stressed University Students for Studying after Taking Swim Class in College (학업스트레스가 높은 대학생의 교양 수영 수업 수강에 따른 자기효능감, 자아존중감 및 생활만족도의 구조적 관계)

  • Lee, Young Jun
    • Journal of the Korean Applied Science and Technology
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    • v.37 no.2
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    • pp.192-205
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    • 2020
  • The purpose of this study is to verify the structural relationship empirically among self-esteem, self-efficacy and life satisfaction of college students who answered that they had high academic stress. SPSS 23.0 and AMOS 21.0 were used to achieve the objectives of this study. In SPSS 23.0, frequency analysis to analyze demographic characteristics, correlation analysis to verify multi-collinearity among the questionnaire scales, and reliability verification to determine the reliability of questionnaire questions were conducted. In AMOS 21.0, confirmatory factor analysis was conducted to verify the construct validity of factors and to verify the causal relationship between variables. To determine the goodness of fit of the model, the 𝑥2 test and the goodness-of-fit index were used. Judging. First, the self-efficacy of college students with high academic stress group through swimming class was positively influenced on self-esteem. Second, the self-efficacy of college students with high academic stress group through swimming class was positively influenced on life satisfaction. Third, the self-esteem of college students with high academic stress group through swimming class was found to affect life satisfaction. This study has significance in demonstrating the problem of academic stress of Korean university students and in proposing expansion of the physical education class as a solution.

The Effects of Communication on Emotional Responses and Store Loyalty at Customer Contact - Focusing on the Moderating Effects of Salesperson's Attributes - (고객 접점에서의 커뮤니케이션이 감정적 반응과 점포 충성도에 미치는 영향 - 판매원 신뢰성과 매력성의 조절효과를 중심으로 -)

  • Kim, Sook-Hee;Kim, Yong-Ho
    • Management & Information Systems Review
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    • v.32 no.2
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    • pp.289-314
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    • 2013
  • This study analyzed differences in the effects of communication with salesperson's on customer's emotional responses and store loyalty at customer contact focusing on the moderating effects of salesperson's attribute. This study recognized the need for expanding the results of the prior researches to widen the understanding of communication, emotional responses, and store loyalty. This study tried to, first, examine the effects of communication between customers and salespersons on emotional responses and store loyalty at customer contact; second, determine the effects of reliability and attractiveness, which are attributes of salespersons, as moderating variables; third, examine relative influences of verbal and nonverbal communication on emotional responses and store loyalty. The results mainly showed, first, that communication significantly affected emotional responses and also had significant effects on arousal as well as positive and negative emotion, contrary to prior researches; second, that emotional responses significantly affected store loyalty; third, there was no difference in influences on emotional responses between verbal and nonverbal communication; fourth, the effects of communication on emotional responses depended on attributes of salespersons, demonstrating interactive effects between communication and attributes of salespersons. This study intended to provide theoretical expansion over relations between variables including the dimension of communication beyond empirical reconfirmation of prior researches. In addition, a strategic scheme was presented to manage positive relations with customers at customer contact.

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Comovement of International Stock Market Price Index (주가동조현상에 관한 연구)

  • Khil, Jae-Uk
    • The Korean Journal of Financial Management
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    • v.20 no.2
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    • pp.181-200
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    • 2003
  • Comovement of international stock market prices has been lately a major controversy in the global stock market. This paper explores whether the common trend has really existed among the US, Japan and Korea's stock markets using the econometric techniques such as VAR, VECM as applied. Pair of indices from the exchange market and the over-the-counter market in each country has been tested, and the exchange market only has been turned out that the common trend existed. The dynamic analyses using the Granger causality test, impulse response function, and the forecast error decomposition have followed to show that the US stock market has played some important role in the Korea and Japan's market in the exchange as well as in the OTC market. The results of the paper imply that the more careful investigation with respect to the co-integration may be necessary in the global market integration studies.

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Comparison of Algal Growth Potentials in the Large Reservoirs and River Mainstream of Naktong River Watershed (낙동강 수계 대형 인공호 및 하천본류의 조류성장 잠재력 비교)

  • You, Kyung-A;Shin, Jae-Ki;Hwang, Soon-Jin
    • Korean Journal of Ecology and Environment
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    • v.39 no.1 s.115
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    • pp.138-144
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    • 2006
  • Algal growth potential test (AGPT) has been used as a tool for assessing biological productivity potential in the aquatic ecosystems. This study was conducted to compare the productivity potentials of large reservoirs (Lakes Andong, Hapchon and Jinyang, and Naktong estuarine dam) and river sites (Sangju, Koryung, and Samlangjin) located in the Naktong River watershed. AGPT was conducted in both non-monsoon and mosoon season (February, April, July and September) of 2003, using Microcystis aeruginosa as a test alga. The AGPs in the reservoirs were relatively much lower than those of river sites. The river AGPs increased towards upstream close to the influent streams, while it generally decreased towards downstream. Immediately after the abrupt increase in influent discharge in summer, the AGP became similar between midstream and downstream sites. The water quality of river and reservoirs deteriorated during the drought period in accordance with AGP: it was the highest during this period. The AGPs showed the closest correlation with the P concentration, leading to the conclusion that bioavailable P is highly influential to the algal growth in both lentic and lotic ecosystems in the Naktong River watershed. Based on the AGPs, the water quality of tested sites was likely eutrophic. Our results suggest that AGPT be a useful tool in evaluating the productivity potential and trophic state of the water body as well as determining the nutrients that limit the growth of algae.