• Bulletin of the Korean Mathematical Society
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• v.52 no.5
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• pp.1495-1515
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• 2015

This paper deals with the numerical methods for the reconstruction of the source term in a linear parabolic equation from final overdetermination. We assume that the source term has the form f(x)h(t) and h(t) is given, which guarantees the uniqueness of the inverse problem of determining the source term f(x) from final overdetermination. We present the regularization methods for reconstruction of the source term in the whole real line and with Neumann boundary conditions. Moreover, we show the connection of the solutions between the problem with Neumann boundary conditions and the problem with no boundary conditions (on the whole real line) by using the extension method. Numerical experiments are done for the inverse problem with the boundary conditions.

• The Transactions of the Korean Institute of Electrical Engineers C
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• v.48 no.2
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• pp.141-146
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• 1999

The eigenvalue equations of multiple waveguides with step-index profile are derived by using the WKB theory. Phase changes unique to step-index discontinuity areintroduced when applying the WKB connection formula to turning points. The transfer matrix method is employed for the analysis of multiple structure and the derived eigenvalue equation are represented in the recursive form. The results by the WKB are compared with those by the FEM for a three-waveguide coupler.

• Journal of the Korean Institute of Telematics and Electronics B
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• v.31B no.5
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• pp.141-148
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• 1994

Both the neural network classifier utilizing multi-layer perceptron and the linear tree classifier composed of hierarchically structured linear discriminating functions can form arbitrarily complex decision boundaries in the feature space and have very similar decision making processes. In this paper, a new method for automatically choosing the number of neurons in the hidden layers and for initalzing the connection weights between the layres and its supporting theory are presented by mapping the sequential structure of the linear tree classifier to the parallel structure of the neural networks having one or two hidden layers. Experimental results on the real data obtained from the military ship images show that this method is effective, and that three exists no siginificant difference in the classification acuracy of both classifiers.

• Structural Engineering and Mechanics
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• v.2 no.3
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• pp.295-309
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• 1994

The present paper concerns the mathematical study and the numerical treatment of the problem of semirigid connections in bolted steel column base plates by taking into account the possibility of appearance of separation phenomena on the contact surface under certain loading conditions. In order to obtain a convenient discrete form to simulate the structural behaviour of a steel column base plate, the continuous contact problem is first formulated as a variational inequality problem or, equivalently, as a quadratic programming problem. By applying an appropriate finite element scheme, the discrete problem is formulated as a quadratic optimization problem which expresses, from the standpoint of Mechanics, the principle of minimum potential energy of the semirigid connection at the state of equilibrium. For the numerical treatment of this problem, two effective and easy-to-use solution strategies based on quadratic optimization algorithms are proposed. This technique is illustrated by means of a numerical application.

• Journal of the Korean Society for Industrial and Applied Mathematics
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• v.11 no.1
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• pp.31-39
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• 2007

A pedagogic model for blood flow is introduced to help medicine majors understand a simplified version of Navier-Stokes equations which is known to be a good tool for interpreting the phenomena in blood flow. The pressure gradient consists of a time-independent part known as Hagen-Poiseuille's gradient and a time-dependent part known as Sexl's, and the model formula for the volume rate of blood flow is reduced to a very simple form. For demonstration, the blood rate in human aorta system is analyzed in connection with the time-dependence of pressure gradient. It is shown for Sexl's part that the flow rate lags the pressure gradient by ${\pi}/2$, which is thought to be due to the relaxation process involved.

• Journal of Photoscience
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• v.11 no.32
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• pp.47-53
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• 2004

A laser scanning fluorescence microscope system has been fabricated for single molecule detection (SMD). Problems associated with the system set-up have been discussed along with proper suggestions. Based on the SMD results obtained by using the apparatus, a statistical method has been suggested to determine the minimum number of required molecules to form a group of uniform average in a selected error range.

• Journal of the Korean Society of Industry Convergence
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• v.12 no.3
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• pp.121-128
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• 2009

This study is for getting sacrificial service, discussing process of sacrificial rituals and understanding the composition of space in Dong-gok Jaesa. For these things, we're arranged for exact blueprint through actual survey and analyzed the architectural features. Dong-gok Jaesa has features which show centripetal space organization with strong closing sparsely. This is intended for sincerity during ritual which is processed without obstruction. This is a mixed form which is unified both straight dwelling and Jung Dang Hyeop Sil type. And this is for all functions which is necessary for Jaesa architecture in only one building. And this is used with organizing technique for space utility with connection of compartments and various enlargement and partition. Through these things, even though it is not a big Jaesa, it shows that this is Korea traditional composition of space technique according to several purposes.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 1993.10a
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• pp.97-102
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• 1993

The application of epxy composite materials for the outdoor insulating systems has some significant advan-tages compared with conventional inorganic materials, that is low weight in combination with high mechanical strength, small dimensions and design versatility. The paper describes the results of high voltage investigations carried out different aging types of epoxy resin insulator and silicone grease coating. The insulators have been exposed 3000 hours to weather-o-meter and 12 months to outdoor. In this connection, the main study of paper is form the basis of develop-ment of principal technologies of epoxy composites which ard: (1)manufacturing of insulator, (2)high vol-tage testing under dry and wet condition, (3)mechani-cal properties, (4)accelerated weather-ometer test and outdoor exposed, artificial polution.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 1998.06b
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• pp.1-3
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• 1998

The 21st century will see the formation of a“Cyber society”that, while separate form the real world, will cooperate with it, leading to the further expansion and development of world society. Cyber society allows the formation of virtual space through the connection of multiple computers in a network. In this virtual space, multiple users can communicate with each other and can collect and exchange information while moving about freely and engaging in activities. Three main technologies are vital to the construction of the Cyber society: platform technology for converting multimedia information to optical signals and performing digital processing and communication processing on such signals; communications network technology for transferring these signals from one point to another; and application technology for configuring the Cyber society that will be formed on this network. This paper describes platform technology and network technology with an emphasis on their relationship to application technology for configuring the Cyber society, and will also discuss InterSpace, one of the cyber society platform system of the Cyber society.

• Journal of Korean Association for Spatial Structures
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• v.1 no.1 s.1
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• pp.135-142
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• 2001

This paper proposes structural analysis on the World Wide Web to form a part of the architectural design project. It purposes modeling space frames and a structural analysis program on the internet only by inputting basic data for forming a shape in the whole phase of space frame analysis. The analysis data is conducted by Oracle DBMS(DataBase Management System), GUI(Graphic User Internet) by Java Applet and connection with server and database by Java Servlet respectively. The result from modeling and analysis is provided as graphic and text file forms by web browsers. Programs can be executed irrespective of user's OS by using internet and highly-secured system is constructed taking advantage of Java. Of great efficiency is maintaining and recycling data as the whole is dealt by database from the beginning to the end of program.