• Korean Journal of Computational Design and Engineering
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• v.4 no.3
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• pp.190-199
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• 1999

Presented in this paper is an algorithm for finding all intersections among polygonal chains with an O((n+k)·log m) worst-case time complexity, where n is the number of lien segments in the polygonal chains, k is the number of intersections, and m is the number of monotone chains. The proposed algorithm is based on the sweep line algorithm. Unlike the previous polygonal-chain intersection algorithms that are designed to handle special only cases, such as convex polygons or C-oriented polygons, the proposed algorithm can handle arbitrarily shaped polygonal chains having self-intersections and singularities (tangential contact, multiple intersections). The algorithms has been implemented and applied to 1) testing simplicity of a polygon, 2) finding intersections among polygons and 3) offsetting planar point-sequence curves.

• Proceedings of the Microbiological Society of Korea Conference
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• 2002.10a
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• pp.118-120
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• 2002

Genetic materials including DNA plasmid are effective delivery vehicle to express interesting gene efficiently and safely not to generate replication competent virus. Moreover, it has advantages to design a better vector and to simplify manufacturing and storage condition. To understand a possible pathogenic mechanism by a flavivirus, West Nile virus (WNV), WNV genome sequence was aligned to other pathogenic viral genome. Interestingly, WNV capsid (Cp) amino acid sequence has some homology to HIV-l Vpr protein. These proteins induce apoptosis in human cell lines as well as in vivo and cell cycle arrest. Therefore, DNA plasmid carrying apoptosis-inducing and cell cycle arresting viral proteins including a HIV-1 Vpr and a WNV Cp protein can be useful for anti-cancer therapeutic applications. This WNV Cp protein is an early expressed protein which can be a reasonable target antigen (Ag) for vaccine design. Immunization of a DNA construct encoding WNV Cp protein induces a strong Ag-specific humoral and Th1-type immune responses in animal. Therefore, DNA plasmid encoding apoptotic viral proteins can be useful tool for therapeutic and prophylactic applications.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2009.05a
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• pp.236-239
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• 2009

Cowl cross bar, a component of automotive cockpit module, has been manufactured by using welding processes of several tube parts with different diameters. However, in order to reduce costs and increase the quality, it is required to develop a new production method to manufacture the cowl cross bar as one-piece In this study, therefore, eliminating the welding process, tube drawing process which is one of metal forming processes was designed by using combined drawing technique. In addition, the selectable range of area reduction ratio was defined as a design guideline and the designed process sequence was verified by finite element analysis.

• Korean Journal of Computational Design and Engineering
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• v.3 no.4
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• pp.274-282
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• 1998

A feature is a local shape of a product directly related to the manufacturing process. The feature plays a role of the bridge connecting CAD and CAM. In the process planning for he CAM, information on manufacturing is required. To get the a manufacturing information from CAD dat, we need to recognize features. Once features are recognized, they are used as an input for the process planning. In this paper, we thoroughly investigate the composite features, which are generated by interacting simple features. The simple features in the composite feature usually have precedence relation in terms of process sequence. Based on the reason for the precedence relation, we classify the composite features for the process planning. In addition to the precedence relation, approach direction is used as an input for the process planning. In the process planning, the number of set-up orientations are minimized whole process sequence for the features are generated. We propose a process planning algorithm based on the topological sort and breadth-first search of graphs. The algorithn is verified using sample products.

• Journal of Industrial Technology
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• v.11
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• pp.115-124
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• 1991

In this study, we design a position controller for two axis servo system. The position controller performs numerical control(NC)to DC or AC servo motor or step motor, and also has a digital input/output sequence capability. The control program composed of position and sequence command, which is called channel, is programmed easily and user-interactively. And it is interpreted and the straight line and arc position command is interpolated. We develop the Z80 microprocessor based system and the software with assembly and C language, and also PC based graphic simulator for the debugging and educational purposes.

• Bulletin of the Korean Chemical Society
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• v.34 no.1
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• pp.121-127
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• 2013

New types of monocyclic ${\beta}$-lactams constitute an important class of compounds due to their unique structures and natures. Here, the design and synthesis of new 4-alkylthio monocyclic ${\beta}$-lactams 2a and 3a are reported. Significantly, compounds 2a and 3a, while keeping a monocyclic system, were designed to contain all of the substructures provided by the cleavage of C(2)-C(3) bond in penicillins. Efficient synthetic pathways for compounds 2a and 3a were established based on two different strategies. Compound 2a was synthesized from raw materials, using 4-acetoxyazetidin-2-one as a key intermediate, through a ten-step synthetic sequence in 3% overall yield. Compound 3a was synthesized from potassium salt of penicillin G (17), using the degraded product 20 as a key intermediate, through a six-step synthetic sequence in 11% overall yield. 4-Alkylthioazetidin-2-one derivatives, introduced in this study, could serve as valuable intermediates for the development of new monocyclic ${\beta}$-lactams.

• Structural Engineering and Mechanics
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• v.34 no.5
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• pp.597-609
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• 2010

A problem formulation and solution methodology for design optimization of laminated thin-walled composite beams of generic section is presented. Objective functions and constraint equations are given in the form of beam stiffness. For two different problems one for open section and the other for closed section, the objective function considered is bending stiffness about x-axis. Depending upon the case, one can consider bending, torsional and axial stiffnesses. The different search and optimization algorithm, known as Evolution Strategies (ES) has been applied to find the optimal fibre orientation of composite laminates. A multi-level optimization approach is also implemented by narrowing down the size of search space for individual design variables in each successive level of optimization process. The numerical results presented demonstrate the computational advantage of the proposed method "Evolution strategies" which become pronounced to solve optimization of thin-walled composite beams of generic section.

• Proceedings of the KIEE Conference
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• 1993.07a
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• pp.447-449
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• 1993

Digital filter is a signal processor which converts the sequence input sampled from analog signal into another sequence output. It includes software routines which filter digital signal, a computer system for executing the routines, and a data acquisition system which implements A/D, D/A signal conversion. In this paper, a data acquisition system is designed and implemented for one-board computer of MC68000. Also, the theory regarding signal conversion and and its problems occured in implementation are considered. And then, with the hardware implemented like this, design of a digital low-pass filter with the cutoff frequency of 200Hz is implemented, and related characteristics are considered.

• Proceedings of the KIEE Conference
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• 2004.05a
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• pp.153-155
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• 2004

In this paper, we design the memory tester chip playing an important role in the memory tester as central parts. Memory tester has the sixteen inner instructions to control the test sequence and the address and data signals to DUT. These instructions are saved in memory with each block such as sequencer and pattern generator. Sequencer controls the test sequence according to instructions saved in the memory. And Pattern generator generates the address and data signals according to instructions saved in the memory, too. We can use these chips for various functional test of memory.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.58 no.8
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• pp.1633-1637
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• 2009

We propose a new technique for sidelobe suppression in orthogonal frequency division multiplexing (OFDM) systems. Sidelobe suppression is an essential technique to design OFDM based overlay system. The proposed technique is based on the combination of the multiple choice sequence (MCS) with the conventional windowing of OFDM signal in time domain. The MCS is choosing the one sequence which has lowest power in sidelobes from the produced set of sequences. The main advantage of proposed technique is that it fully utilizes the available bandwidth to transmit data. Simulation results show that by combining MCS with conventional windowing technique, the sidelobes in OFDM system can be significantly reduced