• 한국전산유체공학회:학술대회논문집
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• 2001.05a
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• pp.60-65
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• 2001

The projectile afterbodies for zero-lift drag reduction has been analyzed using the Navier-Stokes equations with the $\kappa-\epsilon$ turbulence model. The numerical method of a second order upwind scheme has been used on unstructured adaptive meshes. Base drag reduction methods that have been found effective on axisymmetric bodies include boattailing, base bleed, base comustion, locked vortex afterbodies and multistep afterbodies. In this paper, the charateristics of turbulence flow have been studied for geomeries of multistep afterbodies. The important geometrical and flow parameters relevant to the design of such afterbodies have been identified by number, length and height of step. The flow over multistep afterbodies has been analyzed including expansion waves, recompression waves, recirculating flow, shear flow and wake flow. The numerical results have been compared and analyzed with the experimental datum.

• The Transactions of the Korean Institute of Electrical Engineers A
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• v.48 no.6
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• pp.800-806
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• 1999

This paper proposes IIKBAG(Intelligent Interlocking Knowledge Base Generator) which can build automatically the interlocking knowledge base utilized as the real-time interlocking strategy of the electronic interlocking system in order to enhance it's reliability and expansion. The IIKBAG consists of the inference engine and the knowledge base. The former has an auto-learning function which searches all the train routes for the given station model based on heuristic search technique while dynamically searching the model, and then generates automatically the interlocking patterns obtained from the interlocking relations of signal facilities on the routes. The latter is designed as the structure which the real-time expert system embedded on IS(Interlocking System) can use directly in order to enhances the reliability and accuracy. The IIKBAG is implemented in C computer language for the purpose of the build and interface of the station structure database. And, a typical station model is simulated to prove the validity of the proposed IIKBAG.

• Imaging Science in Dentistry
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• v.45 no.1
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• pp.67-72
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• 2015

Arrested pneumatization of the sphenoid sinus is a developmental variant that is not always well recognized and is often confused with other pathologies associated with the skull base. This report describes the case of a patient referred for cone-beam computed tomography (CBCT) imaging for dental implant therapy. CBCT demonstrated a well-defined incidental lesion in the left sphenoid sinus with soft tissue-like density and sclerotic borders with internal curvilinear opacifications. The differential diagnoses included intraosseous lipoma, arrested pneumatization of the sphenoid sinus, chondrosarcoma, chondroid chordoma, and ossifying fibroma. The radiographic diagnosis of arrested pneumatization was based on the location of the lesion, its well-defined nature, the presence of internal opacifications, and lack of expansion. Gray-scale CBCT imaging of the area demonstrated values similar to fatty tissue. This case highlighted the fact that benign developmental variants associated with the skull base share similar radiographic features with more serious pathological entities.

• 한국전산유체공학회:학술대회논문집
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• 1999.11a
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• pp.65-70
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• 1999

Radiative heating of a liquid rocket base plane due to plume emission is numerically investigated. Calculation of flow and temperature fields around rocket nozzle precedes and thereby realistic plume shape and temperature distribution inside the plume are obtained. Based on the calculated temperature field, radiative transfer equation is solved by discrete ordinate method. The averaged radiative heat flux reaching the base plane is about $5kW/m^2$ at the flight altitude of 10.9km. This value is small compared with radiative heat flux caused by constant-temperature (1500K) plume emission, but it is not negligibly small. At higher altitude (29.8km), view factor between the babe plane and the exhaust plume is increased due to the increased expansion angle of the plume. Nevertheless, the radiative heating disappears since the base plane is heated to high temperature (above 1000K) due to convective heat transfer.

• Korea Journal of Hospital Management
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• v.22 no.3
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• pp.46-60
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• 2017

The purpose of this study is to analyze the difference of productivity according to environmental factors among 25 Regional base public hospitals. Also this study is to propose a method to improve the productivity of Regional base public hospitals in the future by improving the public performance and stable management performance by studying the productivity variables affecting profitability. The survey period was based on the last three years, and 25 Regional base public hospitals were selected for the survey. The dependent variable is the total capital medical marginal profitability and the medical profit marginal profitability which are the indicators of profitability. The independent variable, productivity, is classified into three indicators: capital productivity, labor productivity, and value added productivity. The ANOVA analysis method was used to analyze the productivity difference according to the frequency factor and the environmental factors of the Regional base public hospitals. Finally, we conducted a hierarchical regression analysis to examine the productivity variables affecting profitability. The results of this study showed that there were differences in productivity due to environmental factors such as hospital size, competition in the local medical market, and differences in management performance. The difference in productivity and profitability depending on the environmental factors suggests that it is difficult for Regional base public hospitals in each regional base to perform a balanced public service. In order to overcome this, it is necessary to provide balanced medical services such as government financial support expansion, regional medical demand forecasting and facility infrastructure construction.

• Journal of Information Technology Applications and Management
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• v.11 no.2
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• pp.227-237
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• 2004

While the WWW offers an incredibly rich base of information, organized as a hypertext, it does not provide a uniform and efficient way to retrieve specific information. When one tries to find information entering several query terms into a search engine, the highly-ranked pages in the result usually contain many irrelevant or useless pages. The problem is that single-term queries do not contain sufficient information to specify exactly which web pages are needed by the user. The purpose of this paper is to describe the employment of association rules in data mining for developing networks and computing associative coefficient among the terms. And this paper shows how the dynamic query expansion and/or reduction can be performed in information retrieval.

• Journal of computational fluids engineering
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• v.7 no.4
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• pp.35-41
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• 2002

The projectile afterbodies for zero-lift drag reduction has been analyzed using the Navier-Stokes equations with the κ-εturbidence model. The numerical method of a second order upwind scheme has been used on an unstructured adaptive grid system. Base drag reduction methods that have been found effective on axisymmetric bodies are boattailing, base bleed, base combustion, locked vortex afterbodies and multistep afterbodies. In this paper, turbulence flow and pressure charateristics have been studied for geometries of multistep afterbodies. The important geometrical and flow parameters relevant to the design of such afterbodies have been identified by step number, length and height. The flow over multistep aftoerbodies or base have many kinds of compressible flow characteristics including expansion waves at the trailing edge, recompression waves, separation and recirculating flow in the base region, shear flow and wake flow. The numerical results have been compared and analyzed with the experimental data. The flow characteristics have been clearly shown.

• Journal of the East Asian Society of Dietary Life
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• v.26 no.5
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• pp.407-417
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• 2016

Effects of resistant starch as a functional substitute on the quality of Yukwa were determined. Replacement ratios of resistant starch were 2, 4, and 6% of glutinous rice flour. Regarding pasting properties of Yukwa dough replaced with resistant starch, initial pasting temperature significantly increased and peak viscosity significantly decreased with increasing resistant starch. The moisture contents of bandegi and Yukwa base replaced with resistant starch were higher than that of the control. The expansion ratio of Yukwa base replaced with resistant starch significantly decreased with increasing resistant starch, and there were no significant differences in the oil absorption ratio. Lightness (L) of Yukwa base replaced with resistant starch increased significantly with increasing resistant starch. Appearance of Yukwa base replaced with resistant starch showed a shortened length and increased width with increasing resistant starch, and cross-section showed an oval shape, fine air cell distribution, and increased outer layer thickness. Hardness and peak number increased significantly with increasing resistant starch. The overall acceptability of Yukwa base replaced with 6% resistant starch was the highest among the samples, but the result was not significant. The above results show that resistant starch substitution in Yukwa improved the texture and further could improve health functionality due to its dietary fiber content. Resistant starch was appropriate as a 6% replacement for glutinous rice flour in Yukwa.

• International Journal of Naval Architecture and Ocean Engineering
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• v.6 no.4
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• pp.1197-1208
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• 2014

The problem of the oblique water entry of a three dimensional body is considered. Wagner theory is the theoretical framework. Applications are discussed for an elliptic paraboloid entering an initially flat free surface. A dedicated experimental campaign yields a data base for comparisons. In the present analysis, pressure, force and dynamics of the wetted surface expansion are assessed.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2002.07a
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• pp.32-35
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• 2002

The work focuses on the development of a Cu lead-frame with a single-sided adhesive tape for cost reduction and reliability improvement of LOC (lead on chip) package products, which are widely used for the plastic-encapsulation of memory chips. Most of memory chips are assembled by the LOC packaging process where the top surface of the chip is directly attached to the area of the lead-frame with a double-sided adhesive tape. However, since the lower adhesive layer of the double-sided adhesive tape reveals the disparity in the coefficient of thermal expansion from the silicon chip by more than 20 times, it often causes thermal displacement-induced damage of the IC pattern on the active chip surface during the reliability test. So, in order to solve these problems, in the resent work, the double-sided adhesive tape is replaced by a single-sided adhesive tape. The single-sided adhesive tape does net include the lower adhesive layer but instead, uses adhesive materials, which are filled in clear holes of the base film, just for the attachment of the lead-frame to the top surface of the memory chip. Since thermal expansion of the adhesive materials can be accommodated by the base film, memory product packaged using the lead-flame with the single-sided adhesive tape is shown to have much improved reliability. Author allied this invention to the Korea Patent Office for a patent (4-2000-00097-9).