• 유통과학연구
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• 제14권1호
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• pp.93-102
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• 2016

Purpose - The purpose of paper is studying the static and dynamic side for long-term memory storage properties, and increase the explanatory power regarding the long-term memory process by looking at the long-term storage attributes, Korea Composite Stock Price Index. The reason for the use of GPH statistic is to derive the modified statistic Korea's stock market, and to research a process of long-term memory. Research design, data, and methodology - Level shifts were subjected to be an empirical analysis by applying the GPH method. It has been modified by taking into account the daily log return of the Korea Composite Stock Price Index a. The Data, used for the stock market to analyze whether deciding the action by the long-term memory process, yield daily stock price index of the Korea Composite Stock Price Index and the rate of return a log. The studies were proceeded with long-term memory and long-term semiparametric method in deriving the long-term memory estimators. Chapter 2 examines the leading research, and Chapter 3 describes the long-term memory processes and estimation methods. GPH statistics induced modifications of statistics and discussed Whittle statistic. Chapter 4 used Korea Composite Stock Price Index to estimate the long-term memory process parameters. Chapter 6 presents the conclusions and implications. Results - If the price of the time series is generated by the abnormal process, it may be located in long-term memory by a time series. However, test results by price fixed GPH method is not followed by long-term memory process or fractional differential process. In the case of the time-series level shift, the present test method for a long-term memory processes has a considerable amount of bias, and there exists a structural change in the stock distribution market. This structural change has implications in level shift. Stratum level shift assays are not considered as shifted strata. They exist distinctly in the stock secondary market as bias, and are presented in the test statistic of non-long-term memory process. It also generates an error as a long-term memory that could lead to false results. Conclusions - Changes in long-term memory characteristics associated with level shift present the following two suggestions. One, if any impact outside is flowed for a long period of time, we can know that the long-term memory processes have characteristic of the average return gradually. When the investor makes an investment, the same reasoning applies to him in the light of the characteristics of the long-term memory. It is suggested that when investors make decisions on investment, it is necessary to consider the characters of the long-term storage in reference with causing investors to increase the uncertainty and potential. The other one is the thing which must be considered variously according to time-series. The research for price-earnings ratio and investment risk should be composed of the long-term memory characters, and it would have more predictability.

• 성인간호학회지
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• 제20권4호
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• pp.537-547
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• 2008

Purpose: The study aimed to apply Tai Chi exercise to patients with coronary artery disease for 6 months, and to examine changes on body composition, physical strength, and cardiovascular risks. Methods: Applying a quasi experimental design with a nonequivalent control group, 90 subjects with cardiovascular disease were recruited at C university hospital. For 6 months, 44 subjects performed Tai Chi exercise once a week and daily home exercise, while 46 subjects did not. Body composition was assessed by body mass index, % body fat, and waist-hip ratio; physical strength by balance, mobility, flexibility, grip strength, and back muscle strength; and cardiovascular risk checklist for fixed and modifiable risk factors. Data were analyzed by SPSS/WIN program with ANCOVA to consider group differences at the pretest. Results: The subjects were 66 years old in average. In 6 months, Tai Chi group improved significantly in balance, mobility, and flexibility with decreased modifiable cardiovascular risks after adjusting for the pretest scores. Conclusion: Tai Chi exercise was safely applicable to individuals with coronary artery disease, and effective in some measures of physical strength and modifiable cardiovascular risks. It could be an alternative exercise for outpatient cardiac rehabilitation program in this population.

• Journal of Korean Biological Nursing Science
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• 제19권4호
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• pp.215-226
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• 2017

Purpose: The purpose of this study was to investigate the effects of general, health, and alcohol-related characteristics on blood pressure and stress according to the Alcohol Use Disorders Identification Test (AUDIT). Methods: This was a descriptive study. From participants in the 2013 Korea National Health and Nutrition Examination Survey, 319 participants who responded to the survey when they were attending college or university were selected. Data were analyzed using the SPSS Win 23.0 program for composite sample data reflecting the composite design elements of stratification, colonization, and weighting. Results: Mean age of onset of alcohol drinking was $17.91{\pm}0.16$ years, the average AUDIT score was $7.56{\pm}0.41$, and 25 (9.1%) participants fell into the high-risk drinking group. In the high-risk AUDIT group, systolic blood pressure was influenced by age, gender, institution, health status, body mass index, and suicidal ideation, and the explanatory power of the model ($R^2$) was 75.0%. For diastolic blood pressure, institution and health status were the influential factors, and $R^2$ was 66.2%. Predictors of stress were health status, depression, and the age of onset of drinking, and $R^2$ was 57.2%. Conclusion: It was confirmed that the explanatory power of the variables in models of systolic and diastolic blood pressure and stress is greater in those with higher scores on AUDIT.

• Safety and Health at Work
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• 제2권4호
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• pp.301-312
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• 2011

Firefighters and police officers have the third highest prevalence of obesity among 41 male occupational groups in the United States (US). However, few studies have examined the relationship of firefighter working conditions and health behaviors with obesity. This paper presents a theoretical framework describing the relationship between working conditions, health behaviors, and obesity in firefighters. In addition, the paper describes a detailed study plan for exploring the role of occupational and behavioral risk factors in the development of obesity in firefighters enrolled in the Orange County Fire Authority Wellness Fitness Program. The study plan will be described with emphasis on its methodological merits: adopting a participatory action research approach, developing a firefighter-specific work and health questionnaire, conducting both a cross-sectional epidemiological study using the questionnaire and a sub-study to assess the validity of the questionnaire with dietary intake and physical activity measures, and evaluating the strengths and weaknesses of the body mass index as an obesity measure in comparison to skinfold-based percent body fat. The study plan based on a theoretical framework can be an essential first step for establishing effective intervention programs for obesity among professional and voluntary firefighters.

• Journal of Korea Trade
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• 제25권3호
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• pp.65-86
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• 2021

Purpose - This paper empirically investigates the relationship between the corporate value chain and performance of non- financial businesses of South Korean stock market companies. It aims to explore the evidence that can be used to infer the relationship between value chains and corporate performance in the case of firms forming a value chain with other companies with the means of an equity investment or a special business relationship. Design/methodology - Non-financial corporations listed from 2011 to 2017 on the securities market of South Korea are analyzed. The data used for analysis are found for transactions with the related party by year for all the corporations of non-financial industries in the securities market. Multiple analysis attempts are conducted including the relationship between the value chain and productivity, corporate value, risk-adjusted corporate value, and mediation effects of productivity. The empirical model employs sixteen variables including the value chain index which identifies its impact on various aspects of business performances. Findings - The results of this study clearly supports the phenomenon that corporate productivity and value are enhanced when the corporation expands its value chain established with domestic related firms and overseas companies. Such a positive effect is statistically significant even after the possible risk factors that accompany the expansion of value chain were considered, and productivity plays the role as a medicating variable in the effect of the value chain on the corporation values. Originality/value - The findings of this study confirms that domestic companies' expansion of their value chain centered on the related firms overseas that helped them in terms of the maximization of their productivity and corporate values. This study shows that Korean government's policy on expanding the corporate GVC can enhance the productivity and value of firms. The expansion of value chain and its impact on business performance has not been explored thoroughly, although it is getting more and more important in the global trade operation.

• 동서간호학연구지
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• 제29권2호
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• pp.106-116
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• 2023

Purpose: The purpose of this study was to identify the impact of obesity on the incidence of diabetes mellitus in adults with pre-diabetes. Methods: This study employed a longitudinal study design and utilized secondary data drawn from the Korean Genome and Epidemiology Study. This study used data from a sample of 3,693 adults with prediabetes who were followed every two years from 2001 to 2018. Statistical data analysis for frequency, number of cases per 1,000 person-years, log-rank test, Kaplan-Meier curve, and Cox's proportional hazards regression analysis was performed using IBM SPSS statistics version 26. Results: During the observation period, there were 1,309 (35.4%) patients with diabetes, and the total number of person-years was 35,342. The incidence of diabetes was higher in the obese group compared to the normal weight group (body mass index [BMI]: hazard ratio=1.57, 95% confidence interval [CI]=1.40~1.77, waist: hazard ratio=1.55, 95% CI=1.38~1.76, waist to hip ratio [WHR]: hazard ratio=1.53, 95% CI=1.24~1.89, body fat [BF] (%): hazard ratio=1.42, 95% CI=1.27~1.61). Conclusion: An increase in BMI, waist circumference, and WHR, which are indicators of obesity, can exacerbate the risk factors for diabetes. Thus, a decrease in BMI, waist circumference, and WHR is necessary to prevent pre-diabetes. In particular, health care professionals should provide individualized weight management program interventions, including adult obesity programs and obesity counseling in partnership with local health departments, to reduce BMI and waist circumference in people at high risk for diabetes.

• Nutrition Research and Practice
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• 제14권1호
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• pp.62-69
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• 2020

BACKGROUND/OBJECTIVES: A number of studies examined secular trends in blood lipid profiles using time series data of national surveys whereas few studies investigated individual-level factors contributing to such trends. The present study aimed to examine secular trends in dietary and modifiable factors and hyper-LDL-cholesterolemia (HC) prevalence and evaluate their associations using time series data of nationwide surveys. SUBJECTS/METHODS: The study included 41,073 Korean adults aged ≥ 30 years from the 2005, 2007-2009, 2010-2012, 2013-2015, and 2016 Korea National Health and Nutrition Examination Surveys. Stepwise logistic regression analysis was performed to select significant factors associated with HC, which was defined as serum LDL cholesterol levels ≥130 mg/dL. RESULTS: The following factors showed a positive association with HC (P < 0.05): for men having higher body mass index (BMI), being married, having an office job, and consuming higher dairy and vegetable oil products; for women having higher age or BMI, having no job or a non-office job, not in a low-income household, and consuming higher dairy products. In the given model, the 2016 survey data showed that a 2 kg/㎡ reduction in BMI of obese persons resulted in a decreased HC prevalence from 30.8% to 29.3% among men and from 33.6% to 32.5% among women. CONCLUSIONS: Based on these findings, it is suggested that primary prevention programs should advocate having proper BMI for Korean adults with a high-risk of HC. However, whether discouraging consumption of dairy and vegetable oil products can reduce HC prevalence warrants further studies with a prospective longitudinal design.

• 산업경영시스템학회지
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• 제41권2호
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• pp.65-73
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• 2018

The dynamic capabilities of sensing market signals, creating new opportunities and reconfiguring resources and capabilities to new opportunities in a rapidly changing economic environment determines the competitiveness of the enterprise to create added value and survival. This study conceptualized a two-stage performance measurement framework based on the casual model of resource (input)-process-performance (output). We have developed a 'Process capability index' that reflect the dynamic capabilities factors as a key intermediary product linking resource inputs and performance outputs in enterprise performance measurement. The process capability index consists of four elements : manpower (level of human resource), operation productivity, structure and risk management. The DEA (Data Envelopment Analysis) model was applied to the developed performance indicators to analyze the branch office performance of a telecom company. Process capability efficiency (stage 1) uses resource inputs to reach a certain level of process capabilities. In performance result efficiency (stage 2), the process capabilities are used to generate sales revenues and subscribers. The two-stage DEA model derives intermediate output values that optimize the individual stages simultaneously. Some branch offices in the telecom company have focused on process capability efficiency or some other branch offices focused on performance result efficiency. Positioning map using two-stage efficiency decomposition and benchmarking can help identify the sources of inefficiencies and visualize strategic directions for performance optimization. Applications of two-stage DEA in conjunction with the case study that are meaningfully used in performance measurement areas have been scarce. In particular, this paper has the contribution to present a new performance measurement model considering the organization theory, the dynamic capabilities.

• 대한치과교정학회지
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• 제52권6호
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• pp.420-431
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• 2022

Objective: This systematic review aimed to evaluate periodontal parameters in orthodontically tractioned teeth compared with the respective non-tractioned contralateral teeth. Methods: Search strategies were developed for six electronic databases and gray literature. Random-effects meta-analyses were performed for the outcomes of interest. Furthermore, the certainty of the evidence was assessed using the GRADE (Grading of Recommendations Assessment, Development, and Evaluation) tool. Results: Overall, 2,082 articles were identified, of which 24 were selected for the qualitative synthesis. A significant difference was observed between the impacted and contralateral teeth (mean difference [MD] = 0.25; 95% confidence interval [CI] = 0.10-0.40; I² = 0%) when the gingival index was evaluated. Additionally, impacted teeth showed a greater probing depth, with a significant mean difference between the groups (MD = 0.14; 95% CI = 0.07-0.20; I² = 6%). Most studies had a low risk of bias; however, the certainty of the evidence was very low owing to the design of existing studies. Conclusions: The evidence in the literature indicated that tractioned teeth might show worsening of periodontal parameters related to the gingival index and probing depth; however, the evidence remains uncertain about this outcome. Furthermore, probing depth should be considered regarding its clinical significance because of the small effect size observed.

• Journal of Advanced Marine Engineering and Technology
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• 제39권10호
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• pp.1054-1061
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• 2015

The International Maritime Organization (IMO) has been regulating emissions by making mandatory the compliance with institutions aimed at protecting air quality such as the Energy Efficiency Design Index (EEDI), Ship Energy Efficiency Management Plan (SEEMP) and Tier III. Under the circumstances, one of the response measures considered to be the most feasible is the replacement of existing marine fuel with Liquefied Natural Gas (LNG). The industry has been preemptively building infrastructure and developing and spreading engine technology to enable the use of LNG-fueled ships. The IMO, in turn, recently adopted the International Code of Safety for Ships Using Gases or Other Low-Flash-Point Fuels (IGF Code) as an institutional measure. Thus, it is required to comply with regulations on safety-related design and systems focused on response against potential risk for LNG-fueled ships, in which low-flash-point fuel is handled in the engine room. Especially, the Standards of Training, Certification and Watchkeeping (STCW) Convention was amended accordingly. It has adopted the qualification and training requirements for seafarers who are to provide service aboard ships subject to the IGF Code exemplified by LNG-fueled ships. The expansion in the use of LNG-fueled ships and relevant facilities in fact is expected to increase demand for talents. Thus, the time is ripe to develop methods to set up appropriate STCW training courses for seafarers who board ships subject to the IGF Code. In this study, the STCW Convention and existing STCW training courses applied to seafarers offering service aboard ships subject to the IGF Code are reviewed. The results were reflected to propose ways to design new STCW training courses needed for ships subject to the IGF Code and to identify and improve insufficiencies of the STCW Convention in relation to the IGF Code.