• Korean Journal of Fisheries and Aquatic Sciences
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• v.43 no.2
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• pp.159-168
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• 2010

This paper presents a mathematical model and simulation method for investigating the performance of set net systems and fish cage systems influenced by currents and waves. Both systems consist of netting, mooring ropes, a floating collar and sinkers. The netting and ropes were considered flexible structures and the floating collar was considered an elastic structure. Both were modeled on a mass-spring model. The structures were divided into finite elements and mass points were placed at the mid-point of each element, and the mass points were connected by mass-less springs. Each mass point was subjected to external and internal forces and the total force was calculated at every integration step. An implicit integration scheme was used to solve the nonlinear dynamic system. The computation method was applied to dynamic simulation of actual systems simultaneously influenced by currents and waves in order to evaluate their practicality. The simulation results improved our understanding of the behavior of the structure and provided valuable information concerning the optimized design of set net and fish cage systems exposed to an open ocean environment.

• The Bulletin of The Korean Astronomical Society
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• v.36 no.2
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• pp.155.2-155.2
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• 2011

We present development of the calibration system for IGRINS (the Immersion GRating Infrared Spectrograph). We mainly use Th-Ar and U hollow cathode lamp as the spectral calibration source and telluric features can be used additionally. For the flat source, we selected a 3000K tungsten halogen lamp with 2 inch integrating sphere. From Light Tools simulation, the result flat image through calibration optics satisfied <1% flatness error requirement. We also present mechanical design of calibration box that will be attached on the IGRINS dewar. Three moving stages are designed to perform switching mechanism between all of the observing modes - target observation, flat, precision RV measurement, and spectro-polarimetric observation.

• Special Issue of the Society of Naval Architects of Korea
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• 2008.09a
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• pp.106-111
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• 2008

A hull form is 181K DWT Bulk Carrier, of which new design and hull form have been developed using CFD tools and model tests. The basic concept design of hull form has been carried out with considering the factors, which are a lot of influence of the wave and viscosity resistance. The considered factors of particular are LCB, DLWL shape, tern and stem profile, Cp-curve shape, etc. Numerical calculations are carried out in the initial design stage and experimental model tests are also carried out in towing tank of MOERI. The variation of the significantly effective characteristics is carried out to achieve optimized hull form. The results from numerical calculations and model test as well as the design procedures to obtain an optimized hull form resent in this paper.

• Journal of Korean Society for Geospatial Information Science
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• v.3 no.2 s.6
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• pp.173-181
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• 1995

Geospatial analysis method was applied for classification of suitable site for farmstead. Typical urban suburb and rural area was selected and analyzed, that is Cheongwon County in Chungbuk Province, South Korea. In this study, suitable site for the farmstead was classified by five grade in the other site except suitable area for paddy field, upland, settlement and Green Belt, regulated area for development around the city. Digital Elevation Model(DEM), detailed soil map, administration boundary map, stream map and Green Belt map where digitized and scoring tables were composed with scoring standard. In site verification, Geospatial Information System(GSIS) was quite good tools for suitable site classifying for farmstead causing farm household income increasing, environmental impact decreasing and scientific site selection.

• Korea Journal of Hospital Management
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• v.25 no.1
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• pp.32-45
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• 2020

Purpose: The purpose of this research is to develop two medical tourism system models which explain medical tourism phenomenon with a systemic approach. Methodology/Approach: This research was conducted using a qualitative data analysis which mainly refer previous references in relation to medical tourism in the areas of tourism and medicine. Leiper's tourism system model was utilized as a conceptual framework. In-depth interviews with experts in the area were attempted in order to pretest the models. Findings: This research suggests a medical tourism system framework and a medical service provision framework. The first model presents medical tourism components and their relationships within a framework presented in a diagram. The second model shows the relationships among medical services required by medical tourists, the service providers, and service human resources along with movements of medical tourists. Practical Implications: The first model presents a spatial composition of medical tourism components and their relationships, whereas the second model shows the linkage among medical services, the service providers, and relevant service human resources along with time sequential steps of medical tourists. These two models are complementary and may be used as useful tools to observe medical tourism phenomenon with a systemic and holistic approach. These two models may enable stake holders avoid unnecessary confusions and conflicts that result in duplication of government policies and a waste of budget and human resources.

• Journal of the Korean Society for Precision Engineering
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• v.24 no.3 s.192
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• pp.100-107
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• 2007

A internal lobe pump is suitable for oil hydraulics of machine tools, automotive engines, compressors, constructions and other various applications. In particular, the pump is an essential machine element of an automotive engine to feed lubricant oil. The subject of this paper is the theoretical analysis of internal lobe pump whose the main components are the rotors: usually the outer one is characterized by lobes with circular shape, while the inner rotor profile is determined as conjugate to the other. The topic of this paper is the design of a new rotor, which is based on specific performance as different types depending on the shape of the lobe of the outer rotor. First, the design of internal lobe pumps with circular, elliptical, and their combined lobe profiles is considered. The latter is a new type of lobe profile with special shape whose curvature follows a definite function. Then we introduce the performance indexes used for the comparison. Some of these indexes, such as flow rate and flow rate irregularity, are commonly used for the comparison, while specific slipping is particularly suitable in this case. It is possible to notice that the circular and elliptical type is comparable to the circular one or the elliptical one in terms of flow rate irregularity, but has improved performance in terms of specific slipping. Results obtained from the analysis enable the designer and manufacturer of oil pump to be more efficient in this field.

• The KIPS Transactions:PartD
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• v.12D no.6 s.102
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• pp.881-888
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• 2005

As the internet continues to grow, the quantity of information on the Web increases beyond measure. The internet users' abilities and requirements to use information also become varied and complicated. Ontology can describe correct meaning of web resource and relationships between web resources. And it can extract conformable information that a user wants. Accordingly, we need the ontology to represent knowledge. W3C announced OWL(Web Ontology Language), a meaning description technology for such web resources. But, the development of a professional use of tools that can compose and edit effectively is not yet developed adequately. In this paper, we design and implement an Ontology editor which generates and edits OWL documents through intuitional interface, with a OWL parser, a Internal DataModel, and a Serializer.

• Journal for History of Mathematics
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• v.22 no.1
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• pp.53-74
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• 2009

Black-out Game(Lightout, Merlin Game, ${\sigma}$+Game) is an interesting game on the chessboard, when you click a button with black or white color, it changes color of itself and other buttons who shares edges. With this rule, we win the game when we have a chessboard with all same color after we click some of the buttons of it. Pretty much of research has been made on founding the winnable strategy for this type of game. In this paper, we first introduce a history of mathematical modeling on this game. Then we develop an algorithm to offer a winnable blackout game of any size. Our tools also show our new algorithm works. Finally, we show how we can use this game in mathematics education.

• Journal of Animal Science and Technology
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• v.54 no.6
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• pp.463-469
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• 2012

This study utilized a standardization and cluster analysis technique for the selection and classification of beneficial bacteria. A set of synthetic data consisting of 100 individual variables with three characteristics was created for analysis. The three characteristics assigned to each independent variable were designated to have different numeric scales, averages, and standard deviations. The variables were bacterial isolates at random, and the three characteristics were fermentation products, including cell yield, antioxidant activity of culture, and enzyme production. A standardization method utilizing a standard normal distribution equation to record fermentation yields of each isolate was employed to weight their different numeric scales and deviations. Following transformation, the data set was analyzed by cluster analysis. The Manhattan method for dissimilarity matrix construction along with complete linkage technique, an agglomerative method for hierarchical cluster analysis, was employed using statistical computing program R. A total of 100 isolates were classified into groups A, B, and C. In a comparison of the characteristics of each group, all characteristics in groups A and C were higher than those of group B. Isolates displaying higher cell yield were classified as group A, whereas those isolates showing high antioxidant activity and enzyme production were assigned to group C. The results of the cluster analysis can be useful for the classification of numerous isolates and the preparation of an isolation pool using numerical or statistical tools. The present study suggests that a simple technique can be applied to screen and select beneficial microbes using the freely downloadable statistical computing program R.

• Tuberculosis and Respiratory Diseases
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• v.70 no.3
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• pp.261-265
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• 2011

Cholethorax is a bilious pleural effusion caused by a pleurobiliary fistula or leakage of bile into the pleural space. Most cases of cholethorax arise from a complication of abdominal trauma, hepatobiliary infection, or invasive procedures or surgery of hepatobiliary system. However, we experienced a case of a patient with cholethorax of unknown origin. There was no evidence of pleurobiliary fistula or leakage of bile from the hepatobiliary system although we examined the patient with various diagnostic tools including chest and abdominal computed tomography, endoscopic retrograde cholangiopancreatography, tubography, bronchofiberscopy, hepatobiliary scintigraphy and video-assisted thoracoscopic surgery. Herein we report a case of cholethorax for which the specific cause was not identified. The patient was improved by percutaneous drainage of pleural bile.