• Industrial Engineering and Management Systems
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• v.3 no.1
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• pp.1-11
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• 2004

This paper proposes a new algorithm for determining an optimal control input for production systems. In many production systems, completion time should be planned within the due dates by taking into account precedence constraints and processing times. To solve this problem, the max-plus algebra is an effective approach. The max-plus algebra is an algebraic system in which the max operation is addition and the plus operation is multiplication, and similar operation rules to conventional algebra are followed. Utilizing the max-plus algebra, constraints of the system are expressed in an analogous way to the state-space description in modern control theory. Nevertheless, the formulation of a system is currently performed manually, which is very inefficient when applied to practical systems. Hence, in this paper, we propose a new algorithm for deriving a state-space description and determining an optimal control input with several constraint matrices and parameter vectors. Furthermore, the effectiveness of this proposed algorithm is verified through execution examples.

• Korean Journal of Social Welfare
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• v.69 no.4
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• pp.99-125
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• 2017

Recent social studies on space have focused on changing the social relations that activate in space. In general, these studies have been based on the concept of social space on which is grounded the power-relation analysis such as power, oppression, resource allocation, and so on. Social work practice has traditionally recognized the importance of the environment surrounding human beings. Nonetheless, social work practice has tended to comprehend space in a neutral and abstract way because it has insufficiently considered modern spatial theories. For this reason, this study focusing on Lefebvre's social space theory reviewed the contemporary discourses on space in the area of social work practice. Following the review, this study attempted to establish the concept of "Space-based Social Work Practice". Specifically, this study analyzed the actual cases in social work field and explored the applicability of "SSWP". According to the results, this study delivered the implications of Space-based Social Work Practice as an alternative method and suggested the practical direction of SSWP.

• The Journal of the Korea Contents Association
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• v.18 no.4
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• pp.388-397
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• 2018

With the continuous expansion and updating of modern cities, the historical and cultural space of ancient city is under increasing impact from the expansion of modern cities. At present, the regeneration and protection of the ancient city has achieved remarkable results together with poor results. Based on this background, this paper has revealed the power operation behind the space production of three regenerated ancient cities with 'spatial practice', 'representation of space' and '"representation of space' as the framework to, and pointed out the influence of stake holders on space shaping and analysis on the construction of regeneration model. From the perspective of specific materials, society, power, and culture, this paper has analyzed the methods of regeneration construction of Wuzhen ancient city, and provided new methods and reference values for how to regenerate and protect ancient cities. Based on these studies and analysis of the regeneration issues in ancient cities and villages, other historical cultural areas, the paper has indicated that it is necessary to coordinate with the government to clarify the issue of property rights, as well as planners and managers, to activate the regional culture and integrate it with modern culture.

• 지역과문화
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• v.7 no.1
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• pp.1-26
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• 2020

This study analyzes the creation process of local cultural contents that appears in the Maeul-mandeulgi by utilizing the "Village Rituals" handed down from village. The purpose is to analyze the social values and meanings they represent. For this purpose, a qualitative research method using Chilgok-gun Yeong-ori was applied and analyzed through Lefebvre's the production of space theory. Residents began to recognize the necessity of projects such as Maeul-mandeulgi to overcome the community crisis, and attempted to change the perception of existing village rituals. Residents began to recognize the need for projects such as Maeul-mandeulgi to overcome the community crisis, Attempts to change the perception of the existing village rituals resulted in spatial practice. The new cultural contents were created by adding a playful element to the existing Cheonwangje, and thereby strengthening the identity of the village. This resulted in the reproduction of the village as a new cultural space, but it showed the reproduction of the space in which the alienation occurred due to excessive physical expansion. However, through this process, villagers increased their sense of belonging and increased their satisfaction, which showed the process of being produced as a space of representation that strengthens the sense of community.

• New Physics: Sae Mulli
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• v.68 no.11
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• pp.1225-1230
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• 2018

Schwinger pair production of electrons and positrons in a strong electric field is a prediction of nonperturbative quantum field theory, in which the out-vacuum is superposed of multi-particle states of the in-vacuum. Solving the Dirac or Klein-Gordon equation in the background field, though a linear wave equation, and finding the pair-production rate is a difficult or nontrivial job. The phase-integral method has recently been introduced to compute the pair production in space-dependent electric fields, and a complex analysis method has been employed to calculate the pair production in time-dependent electric fields. In this paper, we apply the complex analysis method to a Sauter-type electric field and other hyperbolic-type electric fields that vanish in the past and future and show that the Stokes phenomena in pair production occur when the time-dependent frequency for a given momentum has finite simple poles (polons) with pure imaginary residues.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.2
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• pp.501-513
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• 2017

This study analyzed the situation of urban agriculture development through theories, paradigms, and typology to determine the application frequency and development keywords about space forming. The results showed that urban space by distance determines "Dimension of space forming" through self-production, public-production, and nation-social operation. Second, the complex space by shape determine "Identity of space forming" through "Flat Shape" for using the widespread land, "Compact Shape" for overcoming the small and poor land, and "Fusion of Flat Compact Shape" for systematic use between Flat and Compact. Third, building and interior space according to location determine the "Utility of space forming" through land, roof, wall, veranda, interior, and infrastructure space. The concepts about space forming of urban agriculture have an organic correlation and will be developed sustainably by the evolved cases from now on. In addition, space forming of urban agriculture produces new creation space by various fusion processes and will be a development trend of new urban agriculture.

• Journal of architectural history
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• v.15 no.3
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• pp.27-42
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• 2006

Many contemporary architectural avant gardes tend to use painting as a medium to create architecture which goes beyond the rationalized spatial conception of modem architecture represented by perspectivism. They produce non perspective drawings to represent spatial Ideas, and expand it through poetic imagination to create an unexpected architectural form and space. This paper attempts to analyze the historical origin and background of dominance of drawing in the production of architecture. It was with the invention of perspective that architectural representation became important tool for architectural production. Thereafter, drawing was considered prior to actual building and architecture was considered a three dimensional realization of two dimensional drawing. Modernist avant gardes such as Cubism shattered the rationalized pictorial space of perspective and found a new pictorial space. They tried to extend it to three dimensional space through parallel projection largely based on the Hildebrand's theory of pure visibility. However, due to the ambiguity of the position of the viewing subject, their attempts could not succeed in creating a new architecture. The new architectural avant garde of the 70's rediscovered the early 20th century avant gardes in their attempt to create a new architecture which can register the fragmented spatial condition of contemporary society, and used painting as a medium to create architecture. Their difference from the early avant gardes was that they used poetic imagination rather than parallel projection in the process of projecting three dimensional space and form from the painting. However, their architecture cannot escape the scopic field of perspectivism in that they rely on the picture plane and the distance between object and viewing subject. Therefore, I conclude that in order to create architecture which goes beyond the rationalized space of modern architecture, it is necessary to resort to other tradition of modern architecture than visual one.

• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 2003.09a
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• pp.338-341
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• 2003

Recently, the chaotic method is employed to forecast a near future of uncertain phenomena. This method makes it possible by restructuring an attractor of given time-series data in multi-dimensional space through Takens' embedding theory. However, many economical time-series data are not sufficiently chaotic. In other words, it is hard to forecast the future trend of such economical data on the basis of chaotic theory. In this paper, time-series data are divided into wave components using wavelet transform. It is shown that some divided components of time-series data show much more chaotic in the sense of correlation dimension than the original time-series data. The highly chaotic nature of the divided component enables us to precisely forecast the value or the movement of the time-series data in near future. The up and down movement of TOPICS value is shown so highly predicted by this method as 70％.

• Journal of the Korean Geographical Society
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• v.46 no.2
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• pp.233-256
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• 2011

This research is aimed at providing the possibility for overcoming the current people's status of exclusion and fragmented spaces of urban regions. In this context, it needs to be considered that how the social movements, which are in collusion with spatial characteristics, are proceeding in urban societies. In order to find the clue to such problems, this study is going to investigate the social practice especially based on Lefebvre's theory. Because of the abstract characteristics of Lefebvre's issue, an explicit case of that social theory must be contemplated for practical use of his concepts. For the purpose of proposing such practices, this research has been striving to analyze the case of Mullae Art Village through the method of intelviewing the artists of that place and using the statistical data. And then this research has tried to draw the clue about how to overcome the status of exclusion by considering their spatial movements.

• Journal of the Korean Society of Food Culture
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• v.19 no.2
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• pp.139-149
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• 2004

The age of Queen Victoria, so called nearly 64 years from 1837 to 1901 that Queen Victoria was on the throne. It was the time that ceramicwares and silverwares were mass-produced thanks to the Industrial Revolution and then diverse directions of dining space could be possible in middle class. At the same time, it was the time that the production of bone china, which is main current in modem times, became established, ironstone china began to be developed, and white ceramic wares were accomplished. In addition, factors for the direction of dining space were mass-produced and Gothic style, Classic style, Majolica style, Renaissance, and Neo-rococo style had come back into fashion. Therefore, diverse designs coexisted and had great effect on dining space in this times. This study purposed to establish the decoration theory of dining space following historic flow through researching the designs and the direct factors for dining space in the age of Queen Victoria.