• Korea journal of population studies
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• v.23 no.2
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• pp.5-37
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• 2000

In this paper we have reviewed major theories of international migration by three phases of migration : initiation, perpetuation, and adjustment. Through the review it is found that factors affecting the three phases are not mutually exclusive but interrelated, and argued that for a comprehensive understanding of the phenomena we need a theoretical guideline useful to locate all the important factors associated to the entire process of migration. Neoclassical economic theory which has played a leading role in migration research. fails to be such a guideline. since it is grounded on the unrealistic assumption of rationality and does not take into account for historical-structural factors, as neo-Marxian theorists have claimed. Two major Marxian theories, dual labor market theory and world system theory, have been successful to identify macro-structural factors that induce main flows of international migration, but do not so in exploring situational factors affecting the process of migration, especially social and cultural factors. Accordingly this study proposes that in order to grasp international migration process comprehensively we need to research the phenomena in view of action system theory, that is, to study migrants\` economic, political, social, and cultural situations inclusively.

• Archives of design research
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• v.13 no.1
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• pp.121-130
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• 2000

This study can be expressed by gathered and formed into the exhibition space's structure practical progress/ application. For the one model of fascinating exhibition's space thru inter-space's pertinent adjustment, production between spactator and exhibition constituent on an exhibition story-line, I adjusted the focus to follow mentioned methods systematically for the example; An exhibition space is completed to be very impressive and attractive space by proper adjustment and production of M-M/C interface in exhibition storyline. Quantity space is transfered into quality space through the transmission of an exhibition which can be define as the point of an exhibition structure. And also could de transferd into a bodily sensation space that inherent full of interactive constituent. Changeable exhibition constituents (exhibition item and text) that sporadically expatiated (not trimed, the original form) in the process of an exhibition structure draw much higer quality of the optimal solution in optimize process which is given when aggregate again to contextual flow of synthetic exhibition scenario. Reconstruction of individual exhibition constituents to the new story, that is, transference of exhibition text to exhibition context is inspirit to an exhibition by maximize the exhibition effect in connection can be systematized through carrying out an outcentripetalpart. However, since pattern of an exhibition structure that consequtively meet variety spacetime of an exhibittion environmental can't be exist, this study presents centralizing the exhibition plan of Korea communication pavilion of the annual Expo Comm Wireress Korea, sustained process from design proposal, research and analysis to synthesis, development, transmission and management to an example of an applying crystallization.

• Journal of the Society of Naval Architects of Korea
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• v.48 no.6
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• pp.528-538
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• 2011

As a forming method for curved hull plates more efficient than the flame bending, mechanical bending using multi point press forming and die-less forming is discussed in this paper. the mechanical forming is a flexible manufacturing system for automatically forming of hull parts. It is especially suited to varied curved parts. This paper discusses a multiple point pressing machine composed of a pair of reconfigurable punches in order to achieve the rapid forming of curved hull plates using division forming and presents how forming information is obtained from the given design surface. Although the mechanical forming can be efficient in the metal forming, spring back after pressing is a phenomenon which must be carefully considered when quantifying the process variables. If the spring back is not accurately controlled, the fabricated shell plate cannot meet assembly tolerance. This paper describes the principles to calculate the proper stroke of each punch at the divided areas. the strokes are determined by an iterative process of sequential pressing and spring back compensation from an unfolded flat shape to its given design surface. FEA(finite element analysis) is used to simulate the spring back of the plate and the IDA(iterative displacement adjustment) method adjusts the offset of pressing punches from the deformation results and the design surface. The shape deviations of two surfaces due to spring back are compensated by integrated system using FEA and IDA method. For the practical application, It is aimed to develop an integrated system that can automatically perform the compensation process and calculate strokes of punches of the double sides' reconfigurable multiple-press machine and some experimental results obtained with mechanical bending are presented.

• Korean Journal of Construction Engineering and Management
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• v.13 no.5
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• pp.113-124
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• 2012

TACT process reengineering is applied to the finish work of apartment buildings and extra tall buildings to conduct efficient process control in Korea. Non-systemized information on the performances, however, causes difficulties in building a database for such records and it takes long time to find the relevant information. In order to solve such problems, scientific and quantitative understanding on the construction information and data is required to perform TACT process reengineering satisfactorily and also proper management plan should be provided for the working level staff to understand the required information and data more easily. In this regard, this paper reorganizes the TACT process reengineering based on the general process control and classifies the items of required information to redesign. Redesigned process was verified by specialists making use of work-information matrix. As a result, paper contributed to increasing comprehension level of the working level people and when the persons in charge are transferred to other duty, it makes them understand all the working procedure faster, which enables the departments involved to carry out their cooperation and adjustment more efficiently.

• Macromolecular Research
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• v.12 no.2
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• pp.225-232
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• 2004

We have successfully synthesized relatively monodisperse and cross-linked melamine-formaldehyde (M-F) microspheres by dispersed polycondensation and subsequent pH adjustment with serum replacement cleaning. The average particle sizes (equation omitted): weight-average and (equation omitted) : number-average), the polydispersity index (equation omitted), the number of particles N$\_$p/ and the gel content of the M-F microspheres were observed by varying the pH, the surfactant concentration, and the polymerization temperature. We observed that both the pH and the polymerization temperature were predominant factors in determining (equation omitted) and N$\_$p/, but the effect that the temperature and pH had on the gel content ( ＞ 94% for all samples) was negligible. The exponents of the slopes of plots of N$\_$p/ versus pH and surfactant concentration were －10 and 0.6, respectively. Particle nucleation and growth were achieved within short periods; the incessant coagulation occurred even in the presence of surfactants.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 1993.10a
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• pp.134-152
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• 1993

Many business forecasting problems are characterized by infrequent occurences, a large number of variables, presence of error, and great complexity. Because no forecasting models and tools are effective in handing these problems, managers often use the outcomes of past analogous cases to predict the outcome of the current one. They (1) observe significant attributes in describing a case, (2) identify the past cases similar in these attributes to the current case, and (3) predict the outcome of the current case based on those of the analogous cases identified through some mental simulation and adjustment. This process of forecasting can be termed forecasting-by-analogy. In spite of fairly frequent use of this forecasting process in practice, however, if has not been recognized as a primary forecasting tool, nor applied on a regular basis. In this paper, by automatizing this process using computer models, we develop a case-based forecasting system(CBFS), which identifies relevant cases and applies their outcomes to generate a forecast. We demonstrate the effectiveness of the CBFS in terms of its accuracy in predicting the outcome of the current problem based on the similar cases identified. We compare the forecasting accuracy of the CBFS with that of regression models developed by stepwise procedure under varied simulated problem conditions. The CBFS outperforms regression models in most comparisons. The CBFS could be used as an effective forecasting tool.

• Journal of the Korean Operations Research and Management Science Society
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• v.19 no.2
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• pp.199-215
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• 1994

Many business forecasting problems are characterized by infrequent occurrences, a large number of variables, presence of error, and great complexity. Because no forecasting models and tools are effective in handing these problems, managers often use the outcomes of past analogous cases to predict the outcome of the current one. They (1) observe significant attributes in describing a case, (2) identify the past cases similar in these attributes to the current case, and (3) predict the outcome of the current case based on those of the analogous cases identified through some mental simulation and adjustment. This process of forecasting can be termed forecasting-by-analogy. In spite of fairly frequent use of this forecasting process in practice, however, it has not been recognized as a primary forecasting tool, nor applied on a regular basis. In this paper, by automatizing this process using computer models, we develop a case-based forecasting system (CBFS), which identifies relevant cases and applies their coutcomes to generate a forecast. We demonstrate the effectiveness of the CBFS in terms of its accuracy in predicting the outcome of the current problem based on the similar cases identified. We compare the forecasting accuracy of the CBFS with that of regression models developed by stepwise procedure under varied simulated problem conditions. The CBFS outperforms regression models in most comparisons. The CBFS could be used as an effective forecasting tool.

• The Journal of Industrial Distribution & Business
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• v.11 no.7
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• pp.19-28
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• 2020

Purpose: In this study, we would like to confirm that the transfer of young workers may be a means of enhancing their internal satisfaction, not to get a better job, by setting work-related characteristics that are highly relevant to job-related factors. Research design, data, and methodology: In this study, preparation for turnover was set as dependent variables to identify factors related to the turnover of young people, and the type of business, employment type, debt status, job satisfaction, job difficulty compared to education level, job difficulty, job degree, job major agreement, debt status, and other demographic social characteristics were selected as independent variables. Results: The characteristics related to personal criteria in job-seeking process were significant in the form of business, employment type, job satisfaction, work difficulty compared to the level of education, work difficulty compared to the level of technology, job major matching, and debt status. Conclusions: This study confirmed that young people's turnover may not simply be a means to get a better job, but to increase satisfaction in the internal aspects of their jobs, and that for young people, a job is an important development process that represents their identity and needs to be approached from a life-cycle perspective.

• 연구논문집
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• s.34
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• pp.79-85
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• 2004

There are several types of life test method for hose assemblies. The two major tests used for hose assemblies are impulse test and burst test. And magnification adjustment of impulse pressure, heating of testing oil and repetitive motions of bending and straightening of testing hose are also performed for accelerating the life. According to the manufacture process of hose and swaging process of fitting, there is a difference in the life of hose assemblies from minimum 7 times to maximum 40 times during the life test in the same functioning condition. Like this, the life test of hose which has a wide scope of life distribution gives a problem that observation should take a long time to find out the existence of the bursting from the beginning of the test to the completion of bursting of hose assemblies. Therefore, this research proposes a process of concentrating on the defective section of hose assemblies and maximizing the life acceleration by giving 'Knockdown stress' to hose assemblies just until before the hose assemblies get out of order.

• Transactions of Materials Processing
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• v.10 no.3
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• pp.193-199
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• 2001

Forming more than two parts of sheet metal in a single stamping operation lowers production costs, reduces weight, and heightens dimensional accuracy. The tailored blank (TB) is a laser-welded or mash-seam-welded sheet metal with different thicknesses, different strengths, or different coatings. Recently, automotive manufacturers have been interested in tailored blanks because of their desire to improve the rigidity, weight reduction, crash durability, and cost savings. Therefore the application to auto-bodies has increased. However, as tailored blanks do not behave like un-welded blanks in press forming operations, stamping engineers no longer rely on conventional forming techniques. Field try-outs are very important manufacturing processes for an economic die-making. In the field try-outs, the rounded geometries of tool and the drawbead shape and size in die face are generally modified when the forming defects can not be removed by the adjustment of forming process parameters. In this study, the field try-outs of tailored door inner panel are introduced and evaluated. The behaviours of laser tailored blank associated with different thickness combinations in the forming process of door inner panel are described focusing on terms of experimental investigations on the formability.