• Environmental Engineering Research
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• v.18 no.2
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• pp.85-90
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• 2013

This study is an attempt to quantify rainwater utilization and miscellaneous water demand in Tokyo's 23 special wards, the core of the urban area in Tokyo, Japan, in order to elucidate the potential of further rainwater utilization. The rainwater utilization for miscellaneous appropriate water demands, including toilet flushing, air conditioning, and garden irrigation, were calculated for six different types of building: residential house, office, department store, supermarket, restaurant, and accommodation. Miscellaneous water demands in these different types of building were expressed in terms of equivalent rainfall of 767, 1,133, 3,318, 1,887, 16,574, and 2,227 (mm/yr), respectively, compared with 1,528 mm of Tokyo's average annual precipitation. Building types, numbers and its height were considered in this study area using geographic information system data to quantify miscellaneous water demands and the amount of rainwater utilization in each ward. Area precipitation-demand ratio was used to measure rainwater utilization potential for miscellaneous water demands. Office and commercial areas, such as Chiyoda ward, showed rainwater utilization potentials of <0.3, which was relatively low compared to those wards where many residential houses are located. This is attributed to the relatively high miscellaneous water demand. In light of rainwater utilization based on building level, the introduction of rainwater storage mechanisms with a storage depth of 50 mm for six different types of buildings was considered, and calculated as rainfall of 573, 679, 819, 766, 930, and 787 (mm), respectively. Total rainwater utilization using such storage facilities in each building from 23 wards resulted in the retention of 102,760,000 $m^3$ of water for use in miscellaneous applications annually, and this volume corresponded to 26.3% of annual miscellaneous water demand.

• Journal of the Korean Society for Aviation and Aeronautics
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• v.21 no.4
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• pp.77-89
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• 2013

The purpose of this study is to anticipate the air travel demands over the period of 164 months, from January 1997 to August 2010 using ARIMA-Intervention modeling on the selected sample data. The sample data is composed of the number of the passengers who in the domestic route for Jeju route. In the analysis work of this study, the past events which are assumed to have affected the demands for the air travel routes to Jeju in different periods were used as the intervention variables. The impacts of such variables were reflected in the presupposed demand. The intervention variables used in this study are, respectively, the World Cup event in 2002 (from May to June), 2003 SARS outbreak (from April to May), Tsunami in January 2005, and the influenza outbreak from October to December 2009. The result of the above mentioned analysis revealed that the negative intervention events, like a global outbreak of an epidemic did have negative impact on the air travel demands in a risk aversion by the users of the aviation services. However, in case of the negative intervention events in limited area, where there are possible substituting destinations for the tourists, the impact was positive in terms of the air travel demands for substituting destinations due to the rational expectation of the users as they searched for other options. Also in this study, it was discovered that there is not a binding correlation between a nation wide mega-event, such as the World Cup games in 2002, and the increased air travel demands over a short-term period.

• Journal of the Korean Solar Energy Society
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• v.40 no.1
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• pp.25-33
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• 2020

It has been reported about the energy saving performance of UFAD(under floor air distribution) system and NPC(night purge cooling) system respectively which are applied for commercial buildings. However, when two systems are used at the same time, the effect of heat transfer from floor plenum to slab may vary depending on the operating conditions of NPC. In this study, cooling energy demands were analyzed for building models with UFAD and NPC by using TRNSYS 17 program. UFAD was applied as a cooling system of the base building model, and the cooling energy demands were compared for 64 cases in which the operating time, supply airflow rate, and outdoor air temperature(T_o) of NPC. As a result, it was confirmed that the cooling energy demands were reduced to 30 ~ 80% level compared to UFAD alone, and in particular, the energy demand was reduced in proportion to the supply airflow rate or the operating time while T_o was 16 ~ 20℃. However, when T_o was 22℃, the increase in the supply airflow rate or the operating time results in a disadvantage in terms of cooling energy demands. In addition, the cooling energy demands for UFAD+NPC model were analyzed by applying weather data from three regions with different average outdoor air temperatures. As a result, the cooling energy demand of operating NPC only when T_o was below 20℃ was reduced by 27% compared to that of operating NPC continuously for 8 hours.

• Journal of the Korean Dietetic Association
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• v.24 no.2
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• pp.117-140
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• 2018

The number of patients is increasing and their mean age is also increasing. Proper dietary adjustments are necessary to prevent protein-calorie malnutrition or complications but it is difficult for dialysis patients to adapt to diet therapy due to stress or anorexia. Education does not consider the individual characteristics, knowledge, dietary inhabit education demands, and initial education. The purpose of this study was to identify dialysis patient's nutrition knowledge and, dietary practice and compare those with nutrition education or counseling demands for providing basic data of desirable nutrition management. The data were collected by a survey consisting of the general characteristics, disease related characteristics, nutrition education and counsel characteristics, level of nutrition knowledge, diet therapy, and nutrition education and counsel demands from the 28th March to 22th July 2017. The total number of subjects were 33 patients among dialysis patients at two tertiary medical institutions and an artificial kidney room at a private hospital in Incheon Gyeonggi. The data collected were analyzed statistically using the SPSS program 23.0, followed by further analyses using frequency analysis, one-way ANOVA, cross analysis, and correlation analysis. The results of the dialysis patients showed that younger (P<0.05), female (P<0.05), abnormal high school diploma (P<0.001) groups had high nutrition scores. In addition, dietary practice and nutrition education and counsel demands showed a positive correlation (P<0.05, P<0.01). In particular, females were higher than males in nutrition knowledge, dietary practice, nutrition education, and counseling demand scores.

• Journal of Korean Institute of Industrial Engineers
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• v.39 no.3
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• pp.172-182
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• 2013

In this study we consider a flow line CONWIP system in which two types of product are produced. The processing times of each product type at each station follow an independent exponential distribution and the demands for the finished products of each type arrive according to a Poisson process. The demands that are not satisfied instantaneously are either backordered or lost according to the number of unsatisfied demands that exist at their arrival instants. For this system we develop an approximation method to obtain the performance measures such as steady state probabilities of the number of parts of each product type at each station, mean waiting times of backordered demands and the proportion of backordered demands. For the analysis of the proposed CONWIP system, we model the CONWIP system as a two class closed queueing network with a synchronization station and analyze the closed queueing network using a product-form approximation method for multiple classes developed by Baynat and Dallery. In the approximation method, each subsystem is analyzed using a matrix geometric method. Comparisons with simulation show that the approximation method provides fairly good results for all performance measures.

• Safety and Health at Work
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• v.13 no.2
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• pp.213-219
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• 2022

Objective: The Job Demand & Resources model suggests work characteristics are related to mental well-being and work engagement. Previous work describes the development of a combined construct 'engaged well-being at work' (EWB). To what extent changes in measures of this construct are responsive to changes in job demands and resources or associated with changes in job-related attitudes has not been established. Methods: Longitudinal employee-level data from three waves (German Linked Personnel Panel) were used. Logistic and linear fixed effects regression analyses explored longitudinal associations between changes in EWB for participants over a three-year period with changes in job demands and resources and job-related attitudes (job commitment, satisfaction, and turnover intentions). Results: While job resources were associated with increased odds for a change into a healthier and/or more engaged category of EWB, job demands reduced them. Job resources were more strongly related to higher EWB (OR_range = 1.22 - 1.61) than job demands (OR_range = 0.79 - 0.96). Especially psychological job demands showed negative associations with improved EWB (OR = 0.79). A change from the least desirable category 'disengaged strain' to any other category of EWB was associated with greater odds by up to 20.6 % for increased commitment and job satisfaction and lower odds for turnover intentions. Discussion: Improving work characteristics, especially job resources, could increase employees' EWB, emphasizing the importance of job characteristics for a healthy workplace. Because EWB seems to be associated with job attitudes, an improvement of this indicator would be relevant for employees and employers.

• Structural Engineering and Mechanics
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• v.86 no.5
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• pp.589-605
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• 2023

This paper investigates the ductility demands of steel frames equipped with self-centring fuses under near-fault earthquake motions considering multiple yielding stages. The study is commenced by verifying a trilinear self-centring hysteretic model accounting for multiple yielding stages of steel frames equipped with self-centring fuses. Then, the seismic response of single-degree-of-freedom (SDOF) systems following the validated trilinear self-centring hysteretic law is examined by a parametric study using a near-fault earthquake ground motion database composed of 200 earthquake records as input excitations. Based on a statistical investigation of more than fifty-two (52) million inelastic spectral analyses, the effect of the post-yield stiffness ratios, energy dissipation coefficient and yielding displacement ratio on the mean ductility demand of the system is examined in detail. The analysis results indicate that the increase of post-yield stiffness ratios, energy dissipation coefficient and yielding displacement ratio reduces the ductility demands of the self-centring oscillators responding in multiple yielding stages. A set of empirical expressions for quantifying the ductility demands of trilinear self-centring hysteretic oscillators are developed using nonlinear regression analysis of the analysis result database. The proposed regression model may offer a practical tool for designers to estimate the ductility demand of a low-to-medium rise self-centring steel frame equipped with self-centring fuses progressing in the ultimate stage under near-fault earthquake motions in design and evaluation.

• Proceeding of Spring/Autumn Annual Conference of KHA
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• 2006.11a
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• pp.377-381
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• 2006

The purpose of this study was to suggest the improvement plan for IAQ of the combined officetel and residence through analyzing demands, satisfaction, subjective symptoms and device of residents. For this study, the data was collected from 110 residents by questionnaire survey and an experienced planner by interview. The result showed that the IAQ improvement of the combined officetel and residence was urgent. The educational program about maintenance of IAQ for residents was essentially needed. To recommend eco-friendly materials in process of construction wasimportant so as to take precaution against ‘sick building syndrome'. It was also necessary to improve on the size and shape of ventilation window.

• Proceedings of the Korea Technology Innovation Society Conference
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• 2015.05a
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• pp.508-525
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• 2015

The purpose of this study is to derive the demands to develop marine science technology to reduce damage of disasters caused by boating accidents. This study analyzed the press release to identify the factors of damages that can result from boating accidents and derive the demands for technology development to approach from the perspective of marine science technology to avoid the elements of damage. For this purpose, this study analyzed the contents of about 77,000 articles posted for a month after the tragedy of the Sewol (April 16 - May 15) to derive the keywords and used SNA for the network analysis of each keyword. The findings of the analysis showed that there were five networks and each network consisted of different aspects of technology development to prepare for the marine disasters. Based on these findings, this study derived the demands for technology development from the perspective of marine science technology required to prepare for the possible marine disasters caused by vessels in the future.

• Journal of the Korean housing association
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• v.6 no.1
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• pp.51-66
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• 1995

The Purpose of this study was to examine the environmental characteristics of housing for the elderly preferred by the middle aged. The residential environments include three types of elderly housing differred in the availability of care service as well as indoor and outdoor environmental characteristics of the housing. The results of this study were as follows: The most preferred type of the elderly was the elderly housing with no care service followed by the housing with intermediated care service and dependent housing with full care service. The preferred type of housing for the elderly was significantly related to the demands for the demands for the indoor and outdoor environmental characteristics of the comimg elderly.