• Magazine of the Korean Society of Agricultural Engineers
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• v.35 no.2
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• pp.23-32
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• 1993

This paper describes the background and the development of a hydrologic network flow model. The model was development to simulate daily water demand and supply for selected stream reaches within a watershed, and used as a tool for evaluating, simulating, and planning a water resources system. The proposed network flow model considers daily runoff from subareas, various water demands, and diversion structures within each subarea. Daily streamflow at a reach is simulated after balancing the water demands from subareas. The lateral inflow from subareas is simulated using a modified tank model. Total water demands consist of the daily demands for agricultural, domestic, industrial, livestock, fishery, and environmental uses within a rural district. The return flow, diversions from sources and storage components such as reservoirs were also incorporated into the mode l . The developed model is a generalized version that may be applied to different combinations of river reaches for a given system. This may help potential users identify areas where water supply does not suffice the demands for different time horizons.

• Journal of Korean Biological Nursing Science
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• v.12 no.2
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• pp.114-126
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• 2010

Purpose: To examine the levels of the disease-related knowledge and educational demands of pre-dialysis, chronic renal failure patients at different GFRs and stages. Methods: This study used a cross-sectional survey and aimed at 116 pre-dialysis, chronic renal failure patients, who were registered and received regular treatment from December 1 to December 31, 2009 at the nephrology departments of tertiary medical centers in Seoul. Stages were classified into Stage 3, 4 and 5 depending on GFR ranges. To measure the levels of knowledge and educational demands, the tool, which were first invented by Young Ae Lim (1996) and then modified by Hyo Sun Lim (2005) to adjust the knowledge and educational demands measuring tool for hemodialysis patients to pre-dialysis patients with chronic renal failure, was used. Collected data was analyzed with the SPSS WIN 12.0 program (average, standard deviation, Pearson's correlation coefficient, t-test and ANOVA). Results: There was a significant difference in the disease-related knowledge levels of the subjects at each stage (F=24.41, p=.000). The Scheffe post hoc test confirmed that patients at higher stages had higher levels of knowledge of their disease. Also, although the results showed that patients at higher stages had higher educational demands, there was no significant difference among the groups (F=1.259, p=.288). Conclusion: As patients have different levels of knowledge of the disease and educational demands depending on their stages, it is important to develop and use a systematic education program that reflects the demands and levels of patients at each stage in order to help pre-dialysis patients with chronic renal failure with self-management and improve their quality of life.

• Earthquakes and Structures
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• v.1 no.4
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• pp.327-344
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• 2010

This paper summarizes results of a comprehensive analytical study aimed at evaluating the influence of strong ground motion duration on residual displacement demands of single-degree-of-freedom (SDOF) and multi-degree-of-freedom (MDOF) systems. For that purpose, two sets of 20 earthquake ground motions representative of short-duration and long-duration records were considered in this investigation. While the influence of strong ground motion duration was evaluated through constant-strength residual displacement ratios, $C_r$, computed from the nonlinear response of elastoplastic SDOF systems, its effect on the amplitude and height-wise distribution of residual drift demands in MDOF systems was studied from the response of three one-bay two-dimensional generic frame models. In this investigation, an inelastic ground motion intensity measure was employed to scale each record, which allowed reducing the record-to-record variability in the estimation of residual drift demands. From the results obtained in this study, it was found that long strong-motion duration records might trigger larger median $C_r$ ratios for SDOF systems having short-to-medium period of vibration than short strong-motion duration records. However, taking into account the large record-to-record variability of $C_r$, it was found that strong motion duration might not be statistically significant for most of the combinations of period of vibration and levels of lateral strength considered in this study. In addition, strong motion duration does not have a significant influence on the amplitude of peak residual drift demands in MDOF systems, but records having long strong-motion duration tend to increase residual drift demands in the upper stories of long-period generic frames.

• Journal of Preventive Medicine and Public Health
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• v.52 no.5
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• pp.299-307
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• 2019

Objectives: While occupational stress has long been a central focus of psychological research, few studies have investigated how immigrant microbusiness owners (MBOs) respond to their unusually demanding occupation, or how their unresolved occupational stress manifests in psychological distress. Based on the job demands-resources model, this study compared MBOs to employees with regard to the relationships among emotional demands, job resources, and depressive symptoms. Methods: Data were derived from a cross-sectional survey of 1288 Korean immigrant workers (MBOs, professionals, office workers, and manual workers) aged 30 to 70, living in Toronto and surrounding areas. Face-to-face interviews were conducted between March 2013 and November 2013. Results: Among the four occupational groups, MBOs appeared to endure the greatest level of emotional demands, while reporting relatively lower levels of job satisfaction and job security; but MBOs reported the greatest job autonomy. The effect of emotional demands on depressive symptoms was greater for MBOs than for professionals. However, an inspection of stress-resource interactions indicated that though MBOs enjoyed the greatest autonomy, the protective effects of job satisfaction and security on the psychological risk of emotional demands appeared to be more pronounced for MBOs than for any of the employee groups. Conclusions: One in two Korean immigrants choose self-employment, most typically in family-owned microbusinesses that involve emotionally taxing dealings with clients and suppliers. However, the benefits of job satisfaction and security may protect MBOs from the adverse mental health effects of job stress.

• Communications of Mathematical Education
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• v.33 no.3
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• pp.395-423
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• 2019

The purpose of the study is to analyze the levels of cognitive demands and components of the reasoning process presented in the mathematical sequence section of three high school mathematics textbooks in order to provide implications for the development of reasoning tasks in the future mathematics textbooks. The results of the study have revealed that most of the reasoning tasks presented in the mathematical sequence section of the three high school mathematics textbooks seemed to require low-level cognitive demands and that low-level cognitive demands reasoning tasks required only a component of one reasoning process. On the other hand, only a portion of the reasoning tasks appeared to require high-level of cognitive demands, and high-level cognitive demands reasoning tasks required various components of reasoning process. Considering the results of the study, it seems to suggest that we need more high-level cognitive demands reasoning tasks to develop high-level cognitive reasoning that would provide students with learning opportunities for various processes of reasoning, and that would provide a deeper understanding of the nature of reasoning.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.18 no.4
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• pp.1101-1121
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• 2024

Thorough understanding of user demands and formulation of product development strategies are crucial in product design, and can effectively stimulate consumer behavior. Scientific categorization and classification of demands contribute to accurate design development, design efficiency, and success rates. In recent years, e-commerce has become important consumption platforms for smart wearable products. However, there are few studies on product design and development among those related to promoting platform product services and sales. Meanwhile, design strategies focusing on real consumer needs are scarce among smart wearable product design studies. Therefore, an empirical consumer demand analysis method is proposed and design development strategies are formulated based on a categorized interpretation of demands. Using representative smart bracelets from wearable smart products as a case, this paper classifies consumer demands with three methods: big data semantic analysis, KANO model analysis, and satisfaction analysis. The results reveal that analysis methods proposed herein can effectively classify consumer demands and confirm that differences in consumer demand categories have varying impacts on consumer behavior. On this basis, corresponding design strategies are proposed based on four categories of consumer demands, aiming to make product design the leading factor and promote consumer behavior on e-commerce platforms. This research further enriches demand research on smart wearable products on e-commerce platforms, and optimizes products from a design perspective, thereby promoting consumption. In future research, different data analysis methods will be tried to compare and analyze changes in consumer demands and influencing factors, thus improving research on impact factors of product design in e-commerce.

• Journal of the Korean Chemical Society
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• v.56 no.4
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• pp.518-529
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• 2012

The purpose of this study is to analyze the cognitive demands level of the description about 'element', 'periodic table', and 'atom' on the 'science 2' textbooks by the 2007 revised curriculum. The three types of CAT (Curriculum Analysis Taxonomy) have been used to analyze the cognitive demands level of those contents on the 6 kinds of 'science 2' textbooks. The cognitive demands level about 'elements' on many textbooks is a late concrete operational stage, because the descriptions of 'element' are pure substances or no more split into anything simpler substances. That cognitive demands level about one textbook is a early formal operational stage, because the descriptions 'element' are a substance of one kind of atom. The cognitive demands level of 'periodic table' on many textbooks is a late concrete operational stage, because the descriptions about 'periodic table' are the hierarchical classification for the categorizing reality. And the cognitive demands level of 'periodic table' is a early formal operational stage, because the descriptions about 'periodic table' are a collection of 'families' or two-way gradation of elements. That cognitive demands level about one textbook is a late formal operational stage, because the descriptions of 'periodic table' are a complex classificatory structure linking atomic structure. The cognitive demands level about 'atom' is a early formal operational stage because of the descriptions as "atoms have structure, some atoms are the same, or others are different".

• Journal of the Korean Society of School Health
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• v.30 no.2
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• pp.103-112
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• 2017

Purpose: The Purpose of this study was to examine school health teachers' burnout, engagement, job demands and job resources and to identify the factors that influence burnout and engagement. Methods: The participants were 222 school health teachers working in elementary, middle or high schools. Data were analyzed using descriptive statistics, t-test, ANOVA, Pearson's correlation coefficient, and hierarchical multiple regression. Results: The significant factors influencing burnout were rewards (${\beta}=-.51$), autonomy (${\beta}=-.15$), and job demands (${\beta}=.13$). These factors explained 42% of the variance in burnout. The significant factors influencing engagement were feedback (${\beta}=.49$), rewards (${\beta}=.21$), type of employment (${\beta}=.15$) and autonomy (${\beta}=.13$). These factors explained 49% of the variance in engagement. Conclusion: The study showed that job demands increase burnout, while job resources such as rewards and autonomy alleviate it. In addition, job resources, such as feedback, rewards and autonomy, increase engagement among school health teachers. Therefore, in order to reduce burnout and increase engagement among school health teachers, it is necessary to reduce the level of job demands and to provide enough job resources such as rewards, autonomy and feedback by improving the job environment.

• Computers and Concrete
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• v.19 no.6
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• pp.689-699
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• 2017

An energy-based approach for determining earthquake safety of reinforced concrete frame structures is presented. The developed approach is based on comparison of plastic energy capacities of the structures with plastic energy demands obtained for selected earthquake records. Plastic energy capacities of the selected reinforced concrete frames are determined graphically by analyzing plastic hinge regions with the developed equations. Seven earthquake records are chosen to perform the nonlinear time history analyses. Earthquake plastic energy demands are determined from nonlinear time history analyses and hysteretic behavior of earthquakes is converted to monotonic behavior by using nonlinear moment-rotation relations of plastic hinges and plastic axial deformations in columns. Earthquake safety of selected reinforced concrete frames is assessed by using plastic energy capacity graphs and earthquake plastic energy demands. The plastic energy dissipation capacities of the frame structures are examined whether these capacities can withstand the plastic energy demands for selected earthquakes or not. The displacements correspond to the mean plastic energy demands are obtained quite close to the displacements determined by using the procedures given in different seismic design codes.

• International Journal of Human Ecology
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• v.16 no.1
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• pp.11-23
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• 2015

Although Korean international students/scholars are among the largest groups of international students/scholars on most campuses in the United States, little is known about what types of demands their families face and how they adapt successfully in the face of demands. The purpose of this study was to explore family resilience, which consists of family demands, capabilities, and adaptation, perceived by Korean international student/scholar families, being theoretically guided by the Family Adjustment and Adaptation Response (FAAR) model. Data were collected through face-to-face interviews with couple informants. Following procedures of theory-based content analysis, data were analyzed using key FAAR concepts. Findings showed that most informants reported normative types of family demands such as hardships due to childcare; primary family capabilities were "maintaining social integration," "affective and instrumental communication," and "family cohesiveness," and "nurturance, education, and socialization" was the primary family adaptation mode. New categories under family capabilities, "religious commitment" and "transnational family support" were developed. The results suggest that there is a unique set of family capabilities that contribute to the successful adaptation of Korean international student/scholar families. Implications and limitations are discussed.