• Journal of the Korean Society of School Health
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• v.29 no.3
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• pp.132-139
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• 2016

Purpose: In this study, we analyzed the correlation between high-caffeine energy drink intake and mental health in high school students. Methods: Analyses were conducted using the data of 27,097 responses from the 2015 Korea Youth Risk Behavior Web-based Survey of general high school students. Data were analyzed by logistic regression based on a complex sample design. Results: High-caffeine energy drink intake was positively correlated with the rates of smoking, alcohol consumption, violence, depression, and suicidal thoughts and negatively correlated with the sense of happiness. Conclusion: High-caffeine energy drink intake has a significant impact on the mental health of high school students. Therefore, in-depth research and policies on high-caffeine energy drink intake and the mental health of young individuals are required.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.28 no.8
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• pp.98-105
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• 2014

In this paper, we have analyzed the power consumption property of EVs(Electric Vehicles) chargers established in a public place, proposed reasonable demand factors by the number of established EV chargers and its control method in apartments. The optimization of power system and the suppression of the peak load can be controlled through the proposed demand factors and charging scheduling control algorithm. In this paper, electrical design and an case analysis were carried out on a sample apartment complex to prove the effectiveness of the power system. As a result, emergency power transformer capacity has been reduced by approximately 25%, and we have confirmed that the electric rates saving and the control of peak load value is possible.

• Journal of muscle and joint health
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• v.28 no.1
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• pp.61-69
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• 2021

Purpose: This study investigated the mediating effect of perceived stress in the relationship between subjective health and depression in patients with coronary artery disease. Methods: This secondary analysis study used data from the 2016-2018 Korea National Health and Nutrition Examination Survey (KNHANES). Study participants included 466 patients over 20 years of age with coronary artery disease. Measures included questions about general characteristics, subjective health, perceived stress, and depression. The data were analyzed using complex sample design, descriptive analysis, Rao-Scott ��2 statistic, and multivariate logistic regression analysis with the SPSS 24.0 program. Results: Subjective health influenced depression, and perceived stress partially mediated it. Conclusion: To prevent depression in patients with coronary artery disease, it is necessary to develop effective stress management strategies.

• Journal of muscle and joint health
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• v.28 no.2
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• pp.91-101
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• 2021

Purpose: This study was conducted to identify factors related to osteoporosis prevalence in postmenopausal women. Methods: This study was a secondary analysis research using data from the Eighth Korea National Health and Nutrition Examination Survey (KNHANES VIII-1), 2019, which were downloaded from the KNHANES website. The subjects of this study were 1,791 postmenopausal women who participated in the KNHANES VIII-1, 2019. Data analysis was performed using the IBM SPSS 21.0 program and complex sample design analysis was performed considering factors such as weight, cluster, and strata. Results: Osteoporosis prevalence of in postmenopausal women was 17.5%. Factors related to osteoporosis prevalence were age (65~74 years old, ≥75 years old), house income (low), household type (one-person household), postmenopausal period (10~19 years), drinking (non-drinking). Conclusion: Interventions for osteoporosis prevention and management in postmenopausal women need to focus on women less than 10 years after menopause and one-person household women. Furthermore, it is necessary to expand bone density testing for the early detection of osteoporosis in postmenopausal women.

• ETRI Journal
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• v.46 no.2
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• pp.238-249
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• 2024

Equivalent-time sampling can improve measurement or sensing systems because it enables a broader frequency band and higher delay resolution for periodic signals with lower sampling rates than a Nyquist receiver. Meanwhile, a digital down-conversion (DDC) technique can be implemented using a straightforward radio frequency (RF) circuit. It avoids timing skew and in-phase/quadrature gain imbalance instead of requiring a high-speed analog-to-digital converter to sample an intermediate frequency (IF) signal. Therefore, when equivalent-time sampling and DDC techniques are combined, a significant synergy can be achieved. This study provides a parameter design methodology for optimal equivalent-time sampling using DDC.

• Journal of Families and Better Life
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• v.28 no.2
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• pp.27-37
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• 2010

The purpose of the study was to analyze the constraints that are normally experienced before moving in the context of the household characteristics of households that had recently moved to newly-built apartments. The data for the analysis was collected through a self-administered questionnaire from July 1, 2008 to August 10, 2008. The sample consisted of 251 households in Ulsan living in an apartment complex who had moved within a year. The data from the sample was analyzed by descriptive statistics, factor analysis, and analysis of variance with Duncan's multiple range tests. The results are as follows. The constraints were categorized into information gathering, attractive housing characteristics, expectations of residential mobility, housing development and policies, and resources. Overall, the constraints did not have a huge impact on the performance of the residential mobility of the sample households. Resources, however, were the most influential factors among the five constraints followed by attractive housing characteristics, information gathering, etc. The constraints varied based on the demographic characteristics, such as the household size, duration of marriage, age of the household head, and the socio-economic characteristics, such as the education level of the household head, household income, and the number of mobility. As the number of family members increased, the age of the household head went up, or the level of education went down, the constraints on information gathering were affected in terms of performing residential mobility. Households with a middle aged head with a professional occupation were more constrained by the attractive characteristics of the housing. The impact of the resources related constraints was significantly different based on the number of family members, marriage duration, and the household head's age and occupation, and the number of mobility.

• Journal of Distribution Science
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• v.14 no.6
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• pp.53-63
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• 2016

Purpose - This study examines the effects of the influence strategies on sales representative and headquarter trust, and investigates how sales representative trust plays a mediating role in the relationship between influence strategies and headquarter trust. For these purposes, a structural model which consists of several constructs was developed. In this model, influence strategies that consist of relational influence strategies (information exchange, recommend, promise) and mandatory influence strategies (legal plea, request, threat) were proposed to affect the sales representative trust and in turn, increase the headquarter trust. Thus, this study proposed that sale representative trust plays a core mediating role in the relationship between relational and mandatory influence strategies and headquarter trust in B2B food materials distribution context. Research design, data, and methodology - For these purposes, the authors collected the data from 208 B2B specialized complex agents. We used the 2,200 B2B specialized complex agents which trade with CJ, Ottogi, and Daesang firms and supply food materials to restaurant, school cafeteria, supermarket and traditional market as a sample frame. Once we identified 330 B2B specialized complex agent owners, CEOs, and/or Directors who had agreed to participate in this study, we dropped off a questionnaire at each B2B specialized complex agent and explained the purpose of this study. The survey was conducted from October 1, 2015 to December 15, 2015. A total of 230 questionnaires were collected. Of these collected questionnaires, 28 questionnaires excluded since they had not been fully completed. The data were analyzed using frequency test, reliability test, measurement model analysis, and structural equation modeling with SPSS and SmartPLS 2. Results - First, information exchange, recommendation, and promise of relational influence strategies had positive effects on sales representative trust. The threat of mandatory influence strategies had a negative effect on sales representative trust, but legal plea and request did not have a significant effect on sales representative trust. Second, information exchange and recommendation of relational influence strategies had positive effects on headquarter trust, but promise did not. Also, legal plea, request, and threat of mandatory influence strategies did not have a significant effect on headquarter trust. Third, this findings show that sales representative trust plays a partial mediator between information exchange and headquarter trust, and threat and headquarter trust, and a full mediator between promise and headquarter trust, and recommendation and headquarter trust. Conclusions - The aim of this study was to examine the effects how diverse dimensions of relational and mandatory influence strategies relate to sales representative trust and headquarter trust. To do so, we integrated the influence strategies and the trust transfer theory to hypothesize that various influence strategies increase sales representative and headquarter trust. The findings of this study suggest that headquarter firms should establish and enforce proper influence strategies guidelines to make clear what proper actions sales representatives should implement in relationship with B2B specialized complex agents. Also, relational and mandatory influence strategies must be regarded as a long-term and ongoing strategy that eventually build a long-term orientation with B2B specialized complex agents and guarantee a company's sustainable growth and success.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.34 no.3
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• pp.251-258
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• 2010

This paper presents the technology for the design, fabrication, and characterization of a microfluidic system interface (MSI); the purpose of this technology is to enable the integration of complex microfluidic systems. The MSI technology can be applied in a simple manner for realizing complex arrangements of microfluidic interconnects, integrated microvalves for fluid control, and optical windows for on-chip optical processes. A microfluidic system for the preparation of genetic samples was used as the test vehicle to prove the effectiveness of the MSI technology for packaging complex microfluidic systems with multiple functionalities. The miniaturized genetic sample preparation system comprised several functional compartments, including compartments for cell purification, cell separation, cell lysis, solid-phase DNA extraction, polymerase chain reaction, and capillary electrophoresis. Additionally, the functional operation of the solid-phase extraction and PCR thermocycling compartments was demonstrated by using the MSI.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.31 no.5
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• pp.18-24
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• 2003

The design cycle associated with large engineering systems requires an initial decomposition of the complex system into design processes which are coupled through the transference of output data. Some of these design processes may be grouped into iterative sybcycles. Previous researches predifined the numbers of design processes in groups, but these group sizes should be determined optimally to balance the computing time of each groups. This paper proposes adaptive decomposition method, which determines the group sizes and the order of processes simultaneously to raise design efficiency by expanding the chromosome of the genetic algorithm. Finally, two sample cases are presented to show the effects of optimizing the sequence of processes with the adaptive decomposition method.

• Journal of the Ergonomics Society of Korea
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• v.29 no.6
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• pp.831-841
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• 2010

Usability evaluation of physical products involves characterizing complex physical interactions between humans and products. Human models known as manikins have been widely utilized as usability evaluation tools for automobile interior package design. When combined with computer-aided design software programs, such manikins can be used to simulate driving postures and evaluate driver-interior fits early in the design process, and therefore, may greatly facilitate achieving high-quality design in a cost-efficient manner. The purpose of this study was to define a set of manikins for designing automobile interior packages for the South Korean male population. These manikins were conceptualized as "boundary" manikins, which represent individuals lacking in certain physical capacities or having usability-related issues (e.g., an individual with the 5th percentile forward reach capability, an individual with the 95th percentile shoulder width). Such boundary manikins can serve as an efficient tool for determining if an automobile interior design accommodates the majority of the population. The boundary manikins were selected from the large sample of Korean males whose anthropometric dimensions were described in the recent Size Korea anthropometric database. For each male in the database, his comfortable driving posture was represented using a kinematic body linkage model and various physical capacity measured and usability-related characteristics relevant to driver accommodation were evaluated. For each such measure, a boundary manikin was selected among the Korean males. The manikins defined in this study are expected to serve as tools for ergonomic design of automobile interior packages. The manikin selection method developed in this study was implemented as a generic software program useful for various product design applications.