• Proceedings of the Korean Operations and Management Science Society Conference
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• 2004.10a
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• pp.8-12
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• 2004

In this study we consider a CONWIP system in which the processing times at each station follow a Coxian distribution and the demands for the finished products arrive according to a compound Poisson process. The demands that are not satisfied are backordered according to the number of demands that exist at their arrival instants. For this system we develop an approximation method to calculate order based performance measures such as the mean time of fulfilling a customer order and the mean number o: customer orders. For the analysis of the proposed CONWIP system, we model the CONWIP system as a closed queueing network with a synchronization station and analyze the closed queueing network using a product form approximation method. Numerical tests show that the approximation method provides fairly good estimation of the performance measures of interest.

• Journal of Family Resource Management and Policy Review
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• v.12 no.4
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• pp.103-116
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• 2008

The purpose of this study focused on paternal education semands of fathers. The subjects of this study were 213 in fathers with infant children. The findings of this study were as follows: First, paternal education demands are significantly different according to whether the parents have affectionate or denial child-rearing attitudes. Second, regarding paternal education demands according to child-rearing stresses, such as the sense of obligation and restriction, physical fatigue, the disposition of depression, and psychological damage of a child, these have a significant influence upon paternal education demands.

• Steel and Composite Structures
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• v.10 no.4
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• pp.331-348
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• 2010

Ample research effort has been oriented into developing damage indices with the aim of estimating in a reasonable manner the consequences, in terms of structural damage and deterioration, of severe plastic cycling. Although several studies have been devoted to calibrate damage indices for steel and reinforced concrete members; currently, there is a challenge to study and calibrate the use of such indices for the practical evaluation of complex structures. The aim of this paper is to introduce an energy-based damage index for multi-degree-of-freedom steel buildings that accounts explicitly for the effects of cumulative plastic deformation demands. The model has been developed by complementing the results obtained from experimental testing of steel members with those derived from analytical studies regarding the distribution of plastic demands on several steel frames designed according to the Mexico City Building Code. It is concluded that the approach discussed herein is a promising tool for practical structural evaluation of framed structures subjected to large energy demands.

• Journal of Korean Society of Water and Wastewater
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• v.16 no.6
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• pp.726-732
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• 2002

Pressure drop could happen in the water distribution systems due to pipe breaks or maintenance. The pressure drop causes the water service shutdown and nodal water demands should be reduced in some areas. The conventional analysis method of water distribution systems can not consider the change of nodal water demands caused by these pressure drops. This study is to investigate the variation of nodal water demands according to the nodal water pressure and its effect on the analysis of water distribution systems. For these purpose, one real water service district was selected as a study area. As a result, nodal water demand patterns according to the water pressure could be suggested. Also, we could confirm that the suggested new analysis method for the water distribution systems which considering water pressure drops could be more reliable than the conventional method.

• Journal of Digital Convergence
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• v.16 no.9
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• pp.443-452
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• 2018

The purpose of this study was to examine the effect of job-demands on social worker's organizational commitment. Espically this study focused on the moderating effect of LMX between job-demands and organizational commitment. The sample consisted of 189 social workers in 33 Senior Welfare Centers. The date was analyses using descriptive and multiple regression methods. The major findings of the study firstly were job-demands had negative effect on the social worker's organizational commitment and LMX had positive effect on the social worker's organizational commitment. Secondly, LMX had mederating effect between job-demands and organizational commitment. All these findings were discussed on Social Welfare Center and research.

• Korean Institute of Interior Design Journal
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• no.13
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• pp.216-223
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• 1997

Considering the current rise in elderly population, institutions and facilities caring for the elderly are currently unable to satify the growing needs of the aged wanting the better qualities of life. Therefore, this study will analyze institutions and policies for the elderly in Japan, which has already experienced the rise in elderly population about 30 years earlier than Korea. Because the living conditions of Japan is somewhat similar to that of Korea, analyzing its solutions, both governmental and private, will help better understand the current situations of Korea and possibly offer guidelines as to better serve the growing demands of the aged. In Japan, the social welfare policies directed at caring for the elderly are mainly directed by the government: however, the private services tend to be more adroit at meeting the ever-changing demands of the elderly. Incidentally, the privately owned elderly homes of Japan are a major part of so called the "Silver Industries". The elderly home that are run by private corporations consititute 50 percent of all private institutions for the elderly. These homes tend tobe situated in a city, or near a city environment, serving 25 to 99 people. The types of such homes can be classified from A to D,E,F, reflecting the various services offered by such homes meeting the various demands by the elderly populatiov. Analyzing the social tred of Japan for theelderly, it can be said that the responsibility of the elderly should not only be relied upon the government, but to the society as whole, both public and private. The ever-changing demands of the elderly, wanting better qualities of life, can be better served by systematic analysis of the demands and the various solutions to such demands. Also, the necessary governmental policies in support of elderly welfare, will be needed.be needed.

• Structural Engineering and Mechanics
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• v.20 no.5
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• pp.505-526
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• 2005

The influence of the inter-story structural pounding on the seismic behaviour of adjacent multistory reinforced concrete structures with unequal total heights and different story heights is investigated. Although inter-story pounding is a common case in practice, it has not been studied before in the literature as far as the authors are aware. Fifty two pounding cases, each one for two different seismic excitations, are examined. From the results it can be deduced that: (i) The most important issue in the inter-story pounding is the local effect on the external column of the tall building that suffers the impact from the upper floor slab of the adjacent shorter structure. (ii) The ductility demands for this column are increased comparing with the ones without the pounding effect. In the cases that the two buildings are in contact these demands appear to be critical since they are higher than the available ductility values. In the cases that there is a small distance between the interacting buildings the ductility demands of this column are also higher than the ones of the same column without the pounding effect but they appear to be lower than the available ductility values. (iii) It has to be stressed that in all the examined cases the developed shear forces of this column exceeded the shear strength. Thus, it can be concluded that in inter-story pounding cases the column that suffers the impact is always in a critical condition due to shear action and, furthermore, in the cases that the two structures are in contact from the beginning this column appears to be critical due to high ductility demands as well. The consequences of the impact can be very severe for the integrity of the column and may be a primary cause for the initiation of the collapse of the structure. This means that special measures have to be taken in the design process first for the critically increased shear demands and secondly for the high ductility demands.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.41 no.1
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• pp.50-58
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• 2018

Intermittent demand is a demand with a pattern in which zero demands occur frequently and non-zero demands occur sporadically. This type of demand mainly appears in spare parts with very low demand. Croston's method, which is an initiative intermittent demand forecasting method, estimates the average demand by separately estimating the size of non-zero demands and the interval between non-zero demands. Such smoothing type of forecasting methods can be suitable for mid-term or long-term demand forecasting because those provides the same demand forecasts during the forecasting horizon. However, the smoothing type of forecasting methods aims at short-term forecasting, so the estimated average forecast is a factor to decrease accuracy. In this paper, we propose a forecasting method to improve short-term accuracy by improving Croston's method for intermittent demand forecasting. The proposed forecasting method estimates both the non-zero demand size and the zero demands' interval separately, as in Croston's method, but the forecast at a future period adjusted by binomial weight according to occurrence probability. This serves to improve the accuracy of short-term forecasts. In this paper, we first prove the unbiasedness of the proposed method as an important attribute in forecasting. The performance of the proposed method is compared with those of five existing forecasting methods via eight evaluation criteria. The simulation results show that the proposed forecasting method is superior to other methods in terms of all evaluation criteria in short-term forecasting regardless of average size and dispersion parameter of demands. However, the larger the average demand size and dispersion are, that is, the closer to continuous demand, the less the performance gap with other forecasting methods.

• Journal of Digital Contents Society
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• v.17 no.5
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• pp.349-357
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• 2016

The purpose of this study is to analyze demands of education training about copyright for Infant and early childhood education institutions. This study investigated demands of education training about copyright for infant and early childhood education institutions targeting 248 directors and teachers. Using a questionnaire, research data was analyzed using the program spss. Demands of education training about copyright for infant and early childhood education institutions appeared differently depending on education institution type, position, education career, etc. copyright training topics include the highest demands for understanding of the copyright associated with the work of the early childhood education. Training contents had higher demands for using typeface(font) and video material. So these results reported that directors and teachers require copyright education relating to the work of Early childhood education. The results of this study suggest the implications for developing and implementing copyright training programs for Infant and Early childhood education institutions.

• Education of Primary School Mathematics
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• v.18 no.2
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• pp.61-75
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• 2015

This study analyzed the characteristics of mathematical tasks including the level of cognitive demands set up by pre-service elementary school teachers. 50 pre-service teachers in G university of education who participated in their 4 weeks teaching practicum were selected as subjects. They planned and implemented mathematics lesson with their lesson plans. Lesson plans, video of their lessons, transcript of video were gathered and analyzed the characteristics of mathematical tasks used in their lesson. Through the analysis, several conclusions were drawn as follow. First, 78% of the subjects modified tasks in mathematics textbooks. Since modification or construction of mathematical tasks gives good chance for constructing mathematical task knowledge for teaching, more chance should be given to pre-service teachers to construct new tasks or modify tasks in mathematics textbooks. Second, types of modification done by pre-service teachers were categorized as number change(15.6%), situation change(78.1%) and material change(6.3%). As Chapman(2013) emphasized the importance of MtKT, pre-service teachers must have more MtKT by understanding the characteristics of mathematical tasks. Third, the level of cognitive demands required by mathematical tasks were relatively low. 74% of mathematical tasks was lower cognitive demands and only 26% was higher cognitive demands. The level of cognitive demands of tasks in mathematics textbooks tended to be lowered by the directions given right after the tasks were given. In this respect, the structure of mathematics textbooks need to be changed.