• Title/Summary/Keyword: validity regions

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Development of a Dynamic Offtracking Model on Horizontal Curve Sections (Based on Articulated Vehicles) (도로 평면곡선부에서 동적궤도이탈모형 개발에 관한 연구 (굴절차량을 중심으로))

  • 최재성;김우현
    • Journal of Korean Society of Transportation
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    • v.20 no.3
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    • pp.115-128
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    • 2002
  • Dislike the tangent sections, the horizontal curve sections of roads should be designed, considering several factors : one of such factors is widening. In other words, since widening results from that when a vehicle runs on the horizontal curve sections, the rear wheels of the vehicle run not along with tracks of the front wheels but out of that, such offtracking should be exactly investigated and reflected in design of the curve sections. Especially in the case of industrial roads which semi-trailers and large trucks run frequently or arterial roads with small curve radiuses in mountainous regions. serious offtracking Phenomenons result in increasing the risk of accidents. decreasing the capacities and jeopardizing pedestrians' safety on the curve sections. For the offtracking, widening amounts of roads has been determined under the traditional presumption that vehicles run at a low speed and there is no superelevation. In fact, however, since the vehicles run at a high speed as well as at a low speed and the superelevation is installed on the horizontal curve sections in the structural aspect of roads, the existing standards for installing widening have a limitation to reflect exactly actual Phenomenons. In particular, for articulated wheel axles of a tractor and a trailer and long articulated vehicles, not only the offtracking degree is very high but also the interpretation shows different aspects from one of single axles. Comparing and reviewing the results of Korean and foreign studies related to the trailer offtracking model theory and the standards for installing widening, this study developed a realistic dynamic offtracking model which considers geometric structures of roads and speeds of vehicles, suggested how to measure widening with this model and examined applicability of the model. The findings of this study are as follows ; First. a dynamic offtracking model. which considers dynamic movements of a tractor and a trailer and the superelevation, was developed. Second, a new method to measure widening with the developed dynamic offtracking model was developed and a method to measure widening with swept path width was suggested as well. Finally, validity of the current standards for installing widening was examined by determining actual offtracking and widening amounts with the developed model and the applicability was investigated through the case studies. Compared with the existing offtracking models, the dynamic offtracking model developed in this study can reflect practically vehicle speed. dimension and geometric structural aspects of roads. In conclusion, the meaning of this study is that it reviews validity of the current standards for installing widening and provides a base to establish such standards by suggesting new methods to measure the widening with this dynamic offtracking model.

Assessment of Metabolic Impairment in Alzheimer's Disease with [$^{18}F$]FDG PET: Validity and Role of Simplified Tissue Radioactivity Ratio Analysis (알쯔하이머병에서 양전자방출단층촬영을 이용한 국소뇌포도당대사의 변화에 관한 연구)

  • Kim, Sang-Eun;Na Duk-Lyul;Lee, Jeong-Rim;Choi, Yong;Lee, Kyung-Han;Choe Yearn-Seong;Kim, Doh-Kwan;Kim, Byung-Tae;Lee, Kwang-Ho;Kim, Seung-Tai P.
    • The Korean Journal of Nuclear Medicine
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    • v.30 no.3
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    • pp.299-314
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    • 1996
  • The purpose of the present study was to validate the use of tissue radioactivity ratios instead of regional metabolic rates for the assessment of regional metabolic changes in Alzheimer's disease(AD) with [$^{18}F$]FDG PET and to examine the correlation of ratio indices with the severity of cognitive impairment in AD. Thirty-seven AD Patients(age $68{\pm}9 yrs$, $mean{\pm}s.d.$; 36 probable and 1 definite AD), 28 patients with dementia of non-Alzheimer type(age $66{\pm}7 yrs$), and 17 healthy controls(age $66{\pm}4 yrs$) underwent [$^{18}F$]FDG PET imaging. Two simplified radioactivity ratio indices were calculated from 37-66 min image: region-to-cerebellar radioactivity ratio(RCR) and a composite radioactivity ratio(a ratio of radioactivity in the most typically affected regions over the least typically affected regions: CRR). Local cerebral metabolic rate for glucose(LCMRglu) was also measured using a three-compartment, five-parameter tracer kinetic model. The ratio indices were significantly lower in AD patients than in controls(RCR in temporoparietal cortex, $0.949{\pm}0.136$ vs. $1.238{\pm}0.129$, p=0.0004; RCR in frontal cortex, $1.027{\pm}0.128$ vs. $1.361{\pm}0.151$, p<0.0001; CRR, $0.886{\pm}0.096$ vs. $1.032{\pm}0.042$. p=0.0024). On the RCR analysis, 86% of AD patients showed a pattern of bilateral temporoparietal hypometabolism with or without frontal involvement; hypometabolism was unilateral in 11% of the patients. When bilateral temporoparietal hypometabolism was considered to be suggestive of AD, the sensitivity and specificity of the RCR analysis for the differential diagnosis of AD were 86% and 73%, respectively. The RCR was correlated significantly with the macroparameter K [$K_1k_3/(k_2+k_3)$] (r=0.775, p<0.0001) and LCMRglu(r=0.633, p=0.0002) measured using the kinetic model. In patients with AD, both average RCR of cortical association areas and CRR were correlated with Mini-Mental Status Examination(r=0.565, p=0.0145; r=0.642, p=0.0031, respectively), Clinical Dementia Rating(r=-0.576, p=0.0124; r=-0.591, p=0.0077), and total score of Mattis Dementia Rating Scale (r=0.574, p=0.0648; r=0.737, p=0.0096). There were also significant correlations between memory and language impairments and corresponding regional RCRs. The results suggest that the [$^{18}F$]FDG PET ratio indices, RCR and CRR, reflect global and regional metabolic rates and correlate with the severity of cognitive impairment in AD. The simplified ratio analysis may be clinically useful for the differential diagnosis and serial monitoring of the disease.

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A New Exploratory Research on Franchisor's Provision of Exclusive Territories (가맹본부의 배타적 영업지역보호에 대한 탐색적 연구)

  • Lim, Young-Kyun;Lee, Su-Dong;Kim, Ju-Young
    • Journal of Distribution Research
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    • v.17 no.1
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    • pp.37-63
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    • 2012
  • In franchise business, exclusive sales territory (sometimes EST in table) protection is a very important issue from an economic, social and political point of view. It affects the growth and survival of both franchisor and franchisee and often raises issues of social and political conflicts. When franchisee is not familiar with related laws and regulations, franchisor has high chance to utilize it. Exclusive sales territory protection by the manufacturer and distributors (wholesalers or retailers) means sales area restriction by which only certain distributors have right to sell products or services. The distributor, who has been granted exclusive sales territories, can protect its own territory, whereas he may be prohibited from entering in other regions. Even though exclusive sales territory is a quite critical problem in franchise business, there is not much rigorous research about the reason, results, evaluation, and future direction based on empirical data. This paper tries to address this problem not only from logical and nomological validity, but from empirical validation. While we purse an empirical analysis, we take into account the difficulties of real data collection and statistical analysis techniques. We use a set of disclosure document data collected by Korea Fair Trade Commission, instead of conventional survey method which is usually criticized for its measurement error. Existing theories about exclusive sales territory can be summarized into two groups as shown in the table below. The first one is about the effectiveness of exclusive sales territory from both franchisor and franchisee point of view. In fact, output of exclusive sales territory can be positive for franchisors but negative for franchisees. Also, it can be positive in terms of sales but negative in terms of profit. Therefore, variables and viewpoints should be set properly. The other one is about the motive or reason why exclusive sales territory is protected. The reasons can be classified into four groups - industry characteristics, franchise systems characteristics, capability to maintain exclusive sales territory, and strategic decision. Within four groups of reasons, there are more specific variables and theories as below. Based on these theories, we develop nine hypotheses which are briefly shown in the last table below with the results. In order to validate the hypothesis, data is collected from government (FTC) homepage which is open source. The sample consists of 1,896 franchisors and it contains about three year operation data, from 2006 to 2008. Within the samples, 627 have exclusive sales territory protection policy and the one with exclusive sales territory policy is not evenly distributed over 19 representative industries. Additional data are also collected from another government agency homepage, like Statistics Korea. Also, we combine data from various secondary sources to create meaningful variables as shown in the table below. All variables are dichotomized by mean or median split if they are not inherently dichotomized by its definition, since each hypothesis is composed by multiple variables and there is no solid statistical technique to incorporate all these conditions to test the hypotheses. This paper uses a simple chi-square test because hypotheses and theories are built upon quite specific conditions such as industry type, economic condition, company history and various strategic purposes. It is almost impossible to find all those samples to satisfy them and it can't be manipulated in experimental settings. However, more advanced statistical techniques are very good on clean data without exogenous variables, but not good with real complex data. The chi-square test is applied in a way that samples are grouped into four with two criteria, whether they use exclusive sales territory protection or not, and whether they satisfy conditions of each hypothesis. So the proportion of sample franchisors which satisfy conditions and protect exclusive sales territory, does significantly exceed the proportion of samples that satisfy condition and do not protect. In fact, chi-square test is equivalent with the Poisson regression which allows more flexible application. As results, only three hypotheses are accepted. When attitude toward the risk is high so loyalty fee is determined according to sales performance, EST protection makes poor results as expected. And when franchisor protects EST in order to recruit franchisee easily, EST protection makes better results. Also, when EST protection is to improve the efficiency of franchise system as a whole, it shows better performances. High efficiency is achieved as EST prohibits the free riding of franchisee who exploits other's marketing efforts, and it encourages proper investments and distributes franchisee into multiple regions evenly. Other hypotheses are not supported in the results of significance testing. Exclusive sales territory should be protected from proper motives and administered for mutual benefits. Legal restrictions driven by the government agency like FTC could be misused and cause mis-understandings. So there need more careful monitoring on real practices and more rigorous studies by both academicians and practitioners.

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Cost-Benefit and Spatial Effects of CCTV on Crime Prevention (방범용 CCTV 설치로 인한 경제적·공간적 효과분석)

  • HEO, Sun-Young;MOON, Tae-Heon;KIM, Ju-Young
    • Journal of the Korean Association of Geographic Information Studies
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    • v.21 no.3
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    • pp.63-75
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    • 2018
  • The purpose of this study is to analyze the effects of CCTV installation empirically in the economic and spatial aspects(crime displacement and diffusion effects of crime control benefits), targeting S city in Korea. In terms of economic effects, caused by CCTV installation(2012 and 2013), cost benefit analysis was conducted by means of CCTV installation costs, crime cases, and crime costs per case. The result shows that there is positive effect of 1.34(34%) in 2012. This is slightly higher than the previous study results in Korea(cost effectiveness 1.32), but a little lower than the USA cases(cost effectiveness 1.49). In the case areas in S city, the result proves that the new CCTV has gained economic profit through the crime reduction, compared to the installation expences. However, the cases in 2013 shows no economic profit effect. Secondly, an analysis was conducted in the spatial aspect(crime displacement and diffusion effects of crime control benefits) by using the analysis tool of crime displacement value called WDQ. The results are summarized as follows: The total crimes in three regions had crime diffusion effect but it was less than the direct effect, while in one region, displacement effect was found, but they were less than direct effect. In the case of theft and violence, CCTV had a positive effect, except for one region. The results of the analysis were totally different. Judging from this difference, it may conclude that the effects of CCTV are different by the types of crimes and the places of crimes. The results of this study is meaningful in that it examined and evaluated the effects of the CCTV by scientific and rational measurement tools where previous studies are not many. In addition, it has policy implication for the validity of CCTV and making effective installation plan for crime reduction and prevention.

Investigation on Factors Influencing the Quality of Life of Arthritis Patients (관절염환자의 삶의 질에 영향을 미치는 요인탐색)

  • Oh, Hyun Ja
    • Korean Journal of Adult Nursing
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    • v.12 no.3
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    • pp.431-451
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    • 2000
  • In this paper, I will examine the variables influencing the Quality of Life of arthritis patients and present basic materials which help arthritis patients have positive thinking in life and ultimately lead a satisfactory life. The subjects for this study are 231 inpatients and outpatients with arthritis living in J and K city in Chonbug Province. For the analysis of collected data I employed the SAS program. The variables for characteristics and the quality of life were analysed by descriptive statistics, T-test and ANOVA, and the relations among variables were analysed through Pearson Correlation; the Regression method was employed to predict the factors affecting quality of life. For the validity of reliance on measuring equipment Cronbach Alpha was used. The results of the study are as follows : (1) The mean score of quality of life of arthritis patients is 3.09(5 in the maximum). The general characteristics which affect the quality of life are age(F=5.13, p=0.0006), standard of education(F=6.49, p=0.0003), marriage status(F=7.77, p=0.0005), monthly pay(F=4.37, p=0.0020), medical benefits (F=4.85, p=0.0087), and supports(F=4.39, p=0.0050). For the disease-related characteristics, there is a significant difference in the 6 items: pain control method(F=5.92, p= 0.0002), physical therapy(F=3.25, p=0.013), whethere or not patients exercise(F=4.62, p=0.0000), regularity of exercise(F=4.79, p=0.0000), frequency of exercise(F=6.29, p=0.0001), and amount of exercise(F=4.62, p=0.0043). Depending on the type of arthritis, there is also a significant difference in the degree of pain felt. The patients with infectious arthritis suffer from pain the most, followed by those with gout, rheumatism and degenerative arthritis, in that order. Although statistics don't show any convincing evidence, those with gout perceive that they are in best health condition, followed by those with rheumatism, degenerative arthritis, and infectious arthritis, in that order(F=2.23, p=0.0669). (2) The quality of life of arthritis patients is correlated positively with perceived health status(r=0.56, p=0.0001), health promoting behavior(r=0.53, p=0.0001), family support (r=0.46, p=0.0001), amount of exercise (r=0.36, p=0.0001), ADL(r=0.36, p=0.0001), HLOC(r=0.32, p=0.0001), frequency of exercise(r=0.32, p=0.0001)in that order, while correlated negatively with the degree of pain felt(r=-0.32, p=0.0001), the number of pain regions(r=-0.19, p= 0.0041), and the duration of pain(r=-0.14, p=0.0279). (3) Regression analysis reveals that the most powerful predictor of the quality of life is perceived health status, which account for 31.11%. The other predictors of the quality of life, which account for 60.22%, are health promoting behavior(16.51%), family support(3.81%), ADL(2.52%), gender(1.86%), the number of family members(1.36%), level of pain(1.24%), duration of pain (1.08%), and level of education(0.67%). The results of the study show that perceived health status and health promoting behavior are the two most important variables. However, considering that the perceived health condition is difficult to control by nursing intervention, it is suggested that the level of expectation for patients, must be decided first, and the health promoting behavior and the family support influencing the quality of life must be taken into account as targets for nursing intervention. As a way of controlling the quality of life, I think that a more comprehensive approach comprising the above important variables along with demographic and general characteristics is needed. I also suggest that we must continue to explore the variables affecting the quality of life and include those variables in nursing intervention.

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The Moderating Effect of Social Capital between Organizational Slack and Managerial Practices for Open Innovation in Venture SMEs (벤처중소기업의 조직여유와 개방형 경영혁신 간의 관계에서 사회적 자본의 조절효과 연구)

  • Bae, Hoyoung
    • Asia-Pacific Journal of Business Venturing and Entrepreneurship
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    • v.10 no.5
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    • pp.73-81
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    • 2015
  • This research is designed to analyze the moderating effect of social capital between organizational slack and managerial practices for open innovation. After controlling the firm size, firm age, and environmental uncertainty, we test two hypotheses. First, we test the hypothesis that organizational slack has a positive effect on managerial practices for open innovation. Especially we focus on the managerial innovation and open innovation because recently managerial innovation and open innovation are more and more important. Second, we test the moderating role of social capital between organizational slack and managerial practices for open innovation. Because social capital is a kind of networking activity, we assume that social capital can contribute to managerial practices for open innovation through the networking activity. For this research, we administered the questionnaire surveys, and got the 250 effective data (companies) in Korea. Then we used the validity, reliability, correlation and multiple regression analysis by means of SPSS 18.0. As a result, we can find the two meaningful results. First, organizational slack, especially not absorbed slack but unabsorbed slack, has positive effect on managerial practices for open innovation. It is because absorbed slack such as excessive facilities, machines, or employees is not useful in managerial practices for open innovation. On the other hand, unabsorbed slack is useful in managerial practices for open innovation because unabsorbed slack such as excessive money or securities is very flexible and active. Taken together, the relationship between managerial practices for open innovation and unabsorbed slack is proven in terms of flexibility. Second, social capital has a moderating effect positively between organizational slack, especially not absorbed slack but unabsorbed slack, and managerial practices for open innovation. A prior study related to the relationship between managerial practices for open innovation and social capital doesn't exist yet, so this analysis result is very meaningful in academic respect. But this research has some limitations. First, this research is analyzed by limited region (Korea) and samples (250 companies), so more global regions and samples are recommended in the future. Second, we focus on managerial practices for open innovation in this paper, so the studies about technological practices for open innovation are recommended in the future.

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Development of an evaluation tool for dietary guideline adherence in the elderly (노인의 식생활지침 실천 평가도구 개발)

  • Young-Suk Lim;Ji Soo Oh;Hye-Young Kim
    • Journal of Nutrition and Health
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    • v.57 no.1
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    • pp.1-15
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    • 2024
  • Purpose: This study aimed to develop a comprehensive tool for assessing dietary guideline adherence among older Korean adults, focusing on the domains of food and nutrient intake, eating habits, and dietary culture. Methods: Candidate items were selected through a literature search and expert advice. The degree of adherence to dietary guidelines was then evaluated through a face-to-face survey conducted on 800 elderly individuals across five nationwide regions. The items for dietary guideline adherence evaluation tool were selected through exploratory factor analysis of the candidate items in each of the three areas of the dietary guidelines, and construct validity was verified by performing confirmatory factor analysis. Using the path coefficient of the structural equation model, weights were assigned to each area and item to calculate the dietary guideline adherence score. A rating system for the evaluation tool was established based on national survey results. Results: A total of twenty-eight items were selected for evaluating dietary guideline adherence among the elderly. Thirteen items related to food intake, seven to eating habits, and eight to dietary culture. The average score for dietary guideline adherence was 56.9 points, with 49.8 points in the food intake area, 63.2 points in the eating habits area, and 58.6 points in the dietary culture area. Statistically significant correlations were found between dietary guideline adherence scores and food literacy (r = 0.679) and nutrition quotient scores (r = 0.750). Conclusion: The developed evaluation tool for dietary guideline adherence among Korean older adults can be used as a simple and effective instrument for comprehensively assessing their food and nutrient intake, dietary habits, and dietary culture.