• Journal of Intelligence and Information Systems
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• v.21 no.1
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• pp.15-28
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• 2015

As personal devices and pervasive technologies for interacting with networked objects continue to proliferate, there is an unprecedented world of scattered pieces of contextualized information available. However, the explosive growth and variety of information ironically lead users and service providers to make poor decision. In this situation, recommender systems may be a valuable alternative for dealing with these information overload. But they failed to utilize various types of contextual information. In this study, we suggest a methodology for context-aware recommender systems based on the concept of contextual boundary. First, as we suggest contextual boundary-based profiling which reflects contextual data with proper interpretation and structure, we attempt to solve complexity problem in context-aware recommender systems. Second, in neighbor formation with contextual information, our methodology can be expected to solve sparsity and cold-start problem in traditional recommender systems. Finally, we suggest a methodology about context support score-based recommendation generation. Consequently, our methodology can be first step for expanding application of researches on recommender systems. Moreover, as we suggest a flexible model with consideration of new technological development, it will show high performance regardless of their domains. Therefore, we expect that marketers or service providers can easily adopt according to their technical support.

• Culinary science and hospitality research
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• v.20 no.5
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• pp.111-118
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• 2014

This study sought to describe the relationships among physical environment, self-congruity, positive emotion, and revisit intentions in the coffeehouse setting. This study adopted second-order factor of physical environment in a structural equation model, imploying trend(fashion), cleanliness, reliability, spatial, convenience, and appropriacy as the second-order factors. The conceptual model in this study used responses from 338 college students who visited coffeehouse at least once in the past month. The proposed relationships were analyzed using SPSS 20.0 and AMOS 6.0. The results of data analysis indicated that the six secondorder factors of physical environment significantly affected coffeehouse visitor's self-congruity and positive emotion, and self-congruity as well as positive emotion significantly influenced revisit intentions. Further discussion and theoretical/practical implications of the findings along with directions for future studies are provided. In essence, the findings highlight significant role of coffeehouse's physical environment toward self-congruity and positive emotion in the formation of customer's revisit intentions in the coffeehouse context.

• Journal of The Korean Astronomical Society
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• v.37 no.5
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• pp.421-426
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• 2004

I briefly review the current theoretical status of the origins of ultrahigh energy cosmic rays with special emphasis on models associated with galaxy clusters. Some basic constraints on models are laid out, including those that apply both to so-called 'top-down' and 'bottom-up' models. The origins of these UHECRs remain an enigma; no model stands out as a clear favorite. Large scale structure formation shocks, while very attractive conceptually in this context, are unlikely to be able to accelerate particles to energies much above $10^{18}eV$. Terminal shocks in relativistic AGN jets seem to be more viable candidates physically, but suffer from their rarity in the local universe. Several other, representative, models are outlined for comparison.

• The Bulletin of The Korean Astronomical Society
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• v.38 no.2
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• pp.101.2-101.2
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• 2013

We present a new computational fluid dynamic (CFD) simulation code. The code employs the moving and polyhedral unstructured mesh scheme, which is known as a superior approach to the conventional SPH (smoothed particle hydrodynamics) and AMR (adaptive mesh refinement) schemes. The code first generates unstructured meshes by the Voronoi tessellation at every time step, and then solves the Riemann problem for surfaces of every Voronoi cell to update the hydrodynamic states as well as to move former generated meshes. For the second-order accuracy, the MUSCL-Hancock scheme is implemented. To increase efficiency for generating Voronoi tessellation we also develop the incremental expanding method, by which the CPU time is turned out to be just proportional to the number of particles, i.e., O(N). We will discuss the applications of our code in the context of cosmological simulations as well as numerical experiments for galaxy formation.

• Molecules and Cells
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• v.19 no.2
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• pp.167-179
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• 2005

The cells of metazoans respond to DNA damage by either arresting their cell cycle in order to repair the DNA, or by undergoing apoptosis. This response is highly conserved across species, and many of the genes involved in this DNA damage response have been shown to be inactivated in human cancers. This suggests the importance of DNA damage response with regard to the prevention of cancer. The DNA damage checkpoint responses vary greatly depending on the developmental context, cell type, gene expression profile, and the degree and nature of the DNA lesions. More valuable information can be obtained from studies utilizing whole organisms in which the molecular basis of development has been well established, such as Drosophila. Since the discovery of the Drosophila p53 orthologue, various aspects of DNA damage responses have been studied in Drosophila. In this review, I will summarize the current knowledge on the DNA damage checkpoint response in Drosophila. With the ease of genetic, cellular, and cytological approaches, Drosophila will become an increasingly valuable model organism for the study of mechanisms inherent to cancer formation associated with defects in the DNA damage pathway.

• Journal of the Korean housing association
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• v.12 no.4
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• pp.141-152
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• 2001

This study was conducted to identify the effects of industrialization upon the traditional house and dwelling space and their socio-cultural parameters. By now, in architecture the industrialization has been studied in relation to the formation of modern architecture and the traditional hose or hosing, as though it were a thing already concluded. for this reason, the relationship between industrialization and traditional housing has not been surveyed sufficiently. In reality, the traditional house, however, survives in spite of industrialization, but certainly modified. To examine the effects of industrialization on the traditional house and housing, we must deepen the concepts of both and sow how they are entangled in the socio-cultural context and that they are internal to each other. The parameters does not act independently on the organization of the dwelling space, but in a system formed by them. After all, the combined action of the parameters effected by industrialization entails the de-structuration of the traditional arrangement in traditional house, and tends toward, although it does not realize completely, the re-structuration for the arrangement of intimacy embodied in modern house.

• Korean Institute of Interior Design Journal
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• no.38
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• pp.258-265
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• 2003

The design of space, which focuses on human senses and perception, has become more prominent. It can be understood as the space needed for a field of experience. Phenomenological attitude focuses on the relations between human in the context of their environment. The experiences generated were used as a method of design. The method guides a formation of active space through phenomenological experience in interior space as well as architecture. To stimulate a phenomenological sensitive experience, the parameters for certain experiences were connected to the five senses, finally creating a concrete space. Water, light, air, vapor, and earth as architectural media are connected to the five senses and lead to intermediation from abstract to actual. In particular, water is deeply rooted in peoples subconsciousness and stimulates our instincts. Using water by effectively combining its symbols and physical characteristics will be a method to reinforce the experience with a given space. This study will examine the need for space experience and characteristics of water as an essential elements for perception experience and present possible experimental design.

• Journal of the Korea Society for Simulation
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• v.4 no.1
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• pp.75-86
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• 1995

There has been a great deal of interest in the area of group technology recently. They suggest that group technology's formation of cells of machines which are dedicated to production of families of parts will bring many of the advantages of cellular layout of job shops. In this context, Yoon [2] designed and suggested 3 types of the layout structure for a small firm, by introducing the cellular layout into the traditional flow line of an existing factory. Also he found that P5C, i.e. process layout /5 cells layout, outperformed the rest types. However, he performed the experiments in the standpoint of the existing factory operation and did not consider other operating methods including changing the dispatching and sequencing rules. Therefore, in this paper, we compared the performance of 3 different layout by the simulation technique using the real data from the existing factory, considering a newly suggested dispatching and machine selection rule.

• Bulletin of the Korean Chemical Society
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• v.29 no.1
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• pp.89-93
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• 2008

The key step in a strategy for the synthesis of (+)-lactacystin involving photocyclization reaction of a cyclopenta-fused pyridinium salt has been probed by using a model substrate. Observations made in this effort led to the discovery of a highly unusual cascade process that leads to stereoselective formation of an interesting tricyclic carbamate. The results of this study are presented and discussed in the context of a (+)-lactacystin synthetic approach.

• The Bulletin of The Korean Astronomical Society
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• v.39 no.2
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• pp.65.2-65.2
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• 2014

We present a new hydrodynamic simulation code based on the Voronoi tessellation for estimating the density precisely. The code employs both of Lagrangian and Eulerian description by adopting the movable mesh scheme, which is superior to the conventional SPH (smoothed particle hydrodynamics) and AMR (adaptive mesh refinement) schemes. The code first generates unstructured meshes by the Voronoi tessellation at every time step, and then solves the Riemann problem for all surfaces of each Voronoi cell so as to update the hydrodynamic states as well as to move current meshes. Besides, the IEM (incremental expanding method) is devised to compute the Voronoi tessellation to desired degree of speed, thereby the CPU time is turned out to be just proportional to the number of particles, i.e., O(N). We discuss the applications of our code in the context of cosmological simulations as well as numerical experiments for galaxy formation.