• Korean Journal of Social Welfare
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• v.54
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• pp.221-243
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• 2003

Activity theory explains that the old people participate in social activity as a role-substitute from loss of roles given by work and family. It is possible to enhance their life satisfaction through these activities. Based on this activity theory, this study aims at explore the role substitute of voluntary activities and to analysis whether volunteering commitment has an effect on life satisfaction. Data were collected by using survey questionnaires to the elderly over 55 years old who participated in voluntary activity at 25 Volunteer Centers in Seoul. The Activity theory was operationalized by job or joblessness, family type, achievement type obtained through voluntary activity The results are as follows. (1) Job or joblessness has effect on the activity frequence and activity time. (2) Social achievement after voluntary activity has effect on the duration only (3) And the family type did not have any effect. These three variables of activity theory do not have an effect on life satisfaction. The elderly volunteering commitment was explained by variables other than activity theory such as reward, health, education, sex. And the elderly volunteer's life satisfaction were affected by the family types and their economic status. These results imply that the Korean elderly voluntary activities could be expained partially by Activity theory. Also for these elder volunteers's life satisfaction, qualitative respects such as achievements through voluntary activity, and concerns and support by agencies are more important than the time they imput in voluntary activities.

• 한국기계연구소 소보
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• s.9
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• pp.141-151
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• 1982

An iterative procedure for the calculation of the thick axisymmetric boundary layer and wake near the stern of a body of revolution is presented. Procedure consists of the potential flow calculation by a method of the integral equation of first kind and the calculation of boundary layer and wake by a differential me¬thod of the boundary layer theory. Additionally, higher order terms are included in the conventional momentum equations and continuity equation for the consider¬ation of the characteristics of axisymmetric flow different from the one of two dimentional flow and the thick boundary layer. These solutions are matched at the edge of boundary layer and wake. The results obtained by the present me¬thod are compared with the experimental data and it is found that the nominal wake distribution at the propeller plane of a axisymmetric body is in good agree¬ment with the experiment.

• Korean Institute of Interior Design Journal
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• no.21
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• pp.42-53
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• 1999

The purpose of this study is to clarify the relationship between the exhibits layout and the spatial organization in exhibition spaces. As an analytical method, the space syntax theory devised by Bill Hillier(1984) was applied for analysing the potential differentiation of exhibition spaces and remodeling method in Seoul City Museum selected for case study. The results are as following. Especially from the convex analysis, axial analysis and exhibits(interpretation); 1) the closed spatial system(1F) has high visibility and high intelligibility in hall area but lacks route continuity, 2) the circulated spatial system(2F) has low global visibility but offers high intelligibility and connectivity due to its coercive circulation, 3) and the organization of exhibition design consists in differentiating space that reintegrates them into another spatial order. Therefore, there process are expected to provide a methodological framework for analysing and interpreting spatial organizations of design, leading to the clear explanation of remodeling.

• Journal of Families and Better Life
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• v.14 no.4
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• pp.191-202
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• 1996

This research applied an attachment theory to the study of three generations of women. Questionnaire and semistructured interview techniques were employed to collect the data on intergenerational mother-daughter relationships from 140 triads of adolescent daughters middle-aged mothers an old-aged grandmothers. The focus of the study had been on the characteristics of attachment patterns which is measured by sense of attachment and autonomy across and within generations and their effects on personal well-being. Women in each their three generations perceived a high and seminilar level of attachment across and within the generations. On the other hand the level of autonomy differed by the generations with middle-aged mothers showing a higher level of perceived sense of autonomy than other two generations. Although the levels of attachment and autonomy were related to psychological well-being the level of autonomy was slightly more related to it. The results also showed that not nly one's own attachment toward mother/daughter but attachment of others toward herself were associated with the personal well-being. Overall this study reflects and supports the basis concepts of mother-daughter attachment: its continuity reciprocity and personal development in adulthood.

• Korean Journal of Computational Design and Engineering
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• v.1 no.3
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• pp.234-241
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• 1996

Recently, Genetic Algorithms(GAs), which consist of genetic operators named selection crossover and mutation, are widely adapted into a search procedure for structural optimization. Contrast to traditional optimal design techniques which use design sensitivity analysis results, GAs are very simple in their algorithms and there is no need of continuity of functions(or functionals) any more in GAs. So, they can be easily applicable to wide territory of design optimization problems. Also, virtue to multi-point search procedure, they have higher probability of convergence to global optimum compared with traditional techniques which take one-point search method. The introduction of basic theory on GAs, and the application examples in combination optimization of ten-member truss structure are presented in this paper.

• Journal of Advanced Marine Engineering and Technology
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• v.29 no.7
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• pp.729-735
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• 2005

This paper has dealt with the characteristics of mass and heat transfer of vertical flat plate with free convection. The theory of similarity transformations applied to the momentum and energy equations for free convection. To derive the similarity equation of mass transfer. the equation for conservation of species was added to the continuity. momentum and energy equations. The momentum, energy and species equations set numerically to obtain the velocity, temperature and mass fraction of species as dimensionless. For cases where momentum transport dominates, the thermal boundary layers are shorter than the momentum boundary layer. The relationships between momentum, energy and species were clarified from this study.

• Proceedings of the KSME Conference
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• 2004.11a
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• pp.551-556
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• 2004

The theoretical method is developed to investigate the vibration characteristics of the combined cylindrical shells with an annular plate joined to the shell at any arbitrary axial position. The structural rotational coupling between shell and plate is simulated using the rotational artificial spring. For the translational coupling, the continuity conditions for the displacements of shell and plate are used. For the uncoupled annular plate, the transverse motion is considered and the in-plane motions are not. And the additional transverse and in-plane motions of the coupled annular plate by shell deformation are considered in analysis. Theoretical formulations are based on Love's thin shell theory. The frequency equation of the combined shell with an annular plate is derived using the Rayleigh-Ritz approach. The effect of inner-to-outer radius ratio, axial position and thickness of annular plate on vibration characteristics of combined cylindrical shells is studied. To demonstrate the validity of present theoretical method, the finite element analysis is performed.

• Journal of Ocean Engineering and Technology
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• v.17 no.6
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• pp.7-15
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• 2003

A Digital Wave Tank simulation technique, based on a finite-difference method and a modified marker-and-cell (MAC) algorithm, is applied in order to investigate the characteristics of nonlinear Tsunami propagations and their interactions with a 2D sloping beach, Ohkushiri Island, and to predict maximum wove run-up around the island. The Navier-Stokes (NS) and continuity equation are governed in the computational domain, and the boundary values are updated at each time step, by a finite-difference time-marching scheme in the frame of the rectangular coordinate system. The fully nonlinear, kinematic, free-surface condition is satisfied by the modified marker-density function technique. The near shore Tsunami is assumed to be a solitary wave, and is generated from the numerical wave-maker in the developed Digital Wave Tank. The simulation results are compared with the experiments and other numerical methods, based on the shallow-water wave theory.

• Korean Institute of Interior Design Journal
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• v.13 no.3
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• pp.69-75
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• 2004

Since 1990s, several rising western architects have been moving their theoretical background from the modern paradigm to new science and philosophy. Architectural spaces are based on the philosophy and science of their own age and the architectural theories made by them. And specially, it seems that topological spaces are different to theoretical backgrounds from idealized spaces of modern architecture. From these backgrounds, this study was performed to search for the spacial relationship and characteristics shown in the recently folding architecture and the results of this study that starts this purpose are as follows. First, the architecture that introduced by the theory of topology has appeared as the circulation forms like as Mobius band or Klein bottle, and was made the space fused with structure pursuing liquid properties of matter. As follows, second, the concept of topological space made the division of traditional concept of floor, wall, ceiling disappeared and had built up the space by continual transformation. Third, about the relationship between two spaces in topological space, the two spaces were happened by transformation of these and they have always continuity and the same quality.

• Bulletin of the Korean Mathematical Society
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• v.26 no.2
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• pp.203-209
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• 1989

Recently many authors [2,3,5,6] proved the existence of zeros of accretive operators and estimated the range of m-accretive operators or compact perturbations of m-accretive operators more sharply. Their results could be obtained from differential equations in Banach spaces or iteration methods or Leray-Schauder degree theory. On the other hand Kirk and Schonberg [9] used the domain invariance theorem of Deimling [3] to prove some general minimum principles for continuous accretive operators. Kirk and Schonberg [10] also obtained the range of m-accretive operators (multi-valued and without any continuity assumption) and the implications of an equivalent boundary conditions. Their fundamental tool of proofs is based on a precise analysis of the orbit of resolvents of m-accretive operator at a specified point in its domain. In this paper we obtain a sufficient condition for m-accretive operators to have a zero. From this we derive Theorem 1 of Kirk and Schonberg [10] and some results of Morales [12, 13] and Torrejon[15]. And we further generalize Theorem 5 of Browder [1] by using Theorem 3 of Kirk and Schonberg [10].