• The Korean Journal of Applied Statistics
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• v.27 no.1
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• pp.159-168
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• 2014

The news impact curve(NIC) originally proposed by Engle and Ng (1993) is a graphical representation of volatility for financial time series. The NIC is a simple but a powerful tool for identifying variability of a given time series. It is noted that the NIC is suited to symmetric volatility. Recently a lot of attention has been paid to asymmetric volatility models and therefore asymmetric version of the NIC would be useful in the field of financial time series. In this article, we propose to incorporate LASSO in constructing asymmetric NICs based on asymmetric GARCH models. In particular, bilinear GARCH models are considered and illustrated via KOSDAQ data.

• 제어로봇시스템학회:학술대회논문집
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• 2004.08a
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• pp.1520-1524
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• 2004

This paper describes the development of a robotic maintenance system for use in a maintenance operation of the nozzle dam in a water chamber of a steam generator at the Kori nuclear power plant in Korea. The robotic maintenance system was designed to minimize the personnel exposure to a hazardous radioactive environment. This robotic maintenance system is operated by a teleoperated control which was designed to perform the nozzle dam maintenance tasks in a remote manner without endangering the human workers. Specific maintenance tasks involve the transportation, insertion, and removal of nozzle dams in a water chamber inside a steam generator via a narrow man-way entrance port. The developed robotic maintenance system has two major subsystems: a two degrees of freedom guiding device acting as the main guiding arm and a master-slave manipulator with a kinematic dissimilarity. The mechanical design considerations, control system, and capabilities of the robotic maintenance system are presented. Finally, a graphical representation of the nozzle dam maintenance processes in a simulated work environment are also demonstrated.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.15 no.1
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• pp.157-163
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• 2015

XML has become one of the most influential standard language for representing and exchanging data on internet. However, XML itself has a ability to represent a logical structure for storing and managing data, it is inadequate to use as a conceptual modeling tool because of its complexity for representing the document structures. In this paper, we propose the graphical form of conceptual modeling techniques for representing the structure of the XML schema documents using an extended entity relationship diagram. For this, extended entity relationship model is presented for representing the XML schema structure, transformation rules are presented for transforming extended entity relationship model into XML schema document to show the completeness of the proposed model.

• Journal of The Korean Association of Information Education
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• v.6 no.1
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• pp.117-126
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• 2002

Speaking skill is an important quality in expressing oneself in school life. Quite a few students experience difficulties at school because of the lack of adequate speaking ability. In order to help them, a Web-based speaking enhancement system is designed and developed using computers equipped with multimedia devices with which students can practice speaking while they are observing graphical representation of voices, which is to cause interest and voluntary participation in the learning activity. The learning system was tested on a group of 44 students of 4th grade in an elementary school. The students were divided into three smaller groups in terms of speaking ability. The experiment shows the effectiveness of the system in building speaking ability.

• Computers and Concrete
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• v.18 no.5
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• pp.983-998
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• 2016

Structural optimization is one of the most important topics in structural engineering and has a wide range of applicability. Therefore, the main objective of the present study is to apply the Lagrange Multiplier Method (LMM) for minimum cost design of singly and doubly reinforced rectangular concrete beams. Concrete and steel material costs are used as objective cost function to be minimized in this study, and ultimate flexural strength of the beam is considered to be as the main constraint. The ultimate limit state method with partial material strength factors and equivalent concrete stress block is used to derive general relations for flexural strength of RC beam and empirical coefficients are taken from topic 9 of the Iranian National Building Regulation (INBR9). Optimum designs are obtained by using the LMM and are presented in closed form solutions. Graphical representation of solutions are presented and it is shown that proposed design curves can be used for minimum cost design of the beams without prior knowledge of optimization and without the need for iterative trials. The applicability of the proposed relations and curves are demonstrated through two real life examples of SRB and DRB design situations and it is shown that the minimum cost design is actually reached using proposed method.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.20 no.11
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• pp.3525-3537
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• 1996

This paper presents a CAD program develpoed on a microcomputer in order to support graphic and computational assessment of ergonomic problems associated with the design of a man-in-cab system. The program is coded to help workspace designers with ergonomic evaluations needed in the design stage. This paper proposed a biomechanical -ergonomic evaluations needed using man and workplace models. The human model is developed to have dimensions obtained from the Korean anthropometric data reported in 1992. Its graphical representation is based on a wire-frame model but, whenever necessary, body segments can be represented by a solid model with hidden line/faces removed and shaded. Workplace models are presented for cabs of the excavator, one of the most popular construction vehicles. A workplace model consists of an operator seat, a steering wheel. two control levers, two pedals, and a control panel. The workplace elements can be modified in their sizes, positions, and orientations by changing the reference point and design parameters. An algorithm for the view test is suggested and loaded to provide a visual evaluaiton of the overall layout of a workplace model.

• Transactions of the Korean Society of Machine Tool Engineers
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• v.13 no.5
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• pp.38-48
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• 2004

Recently the use of high-speed equipment in machine-tool industry has greatly increased, which requires the development of prognostics and prediction methods on the design stage. Conversion of the test/experiments stage from real to virtual reality will not only significantly reduce the design and manufacturing cost, but will also increase design quality. This paper shows how it is possible to develop the automated system for the design calculations of the air-bearing spindles. First, the general calculation method is introduced. It contains several steps, namely, geometry identification, pressure calculation, stiffiness calculation, dynamics characteristics calculation. For geometry identification reducing spindle shaft to rings was proposed, which helps to automate the calculation process. For pressure calculation the Peshti method was implemented. For stiffiness calculation the analysis was made, which shown the necessity of correct calculation step selection. Then the system of ordinary differential equations containing influence coefficients was evolved, which is used for trjectories calculation. The graphical representation of the calculation results shows the dynamic behavior of the spindle unit concerning various working conditions. Finally, this automated system is illustrated by an example of the air-bearing spindle calculation.

• International Journal of CAD/CAM
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• v.6 no.1
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• pp.183-192
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• 2006

A CAD/CAM system has been developed for rapid prototyping (RP) of microfluidic devices based on excimer laser micromachining. The system comprises of two complementary softwares. One, the CAM tool, creates part programs from CAD models. The other, the Simulator Tool, uses a part program to generate the laser tool path and the 2D and 3D graphical representation of the machined microstructure. The CAM tool's algorithms use the 3D geometry of a microstructure, defined as an STL file exported from a CAD system, and process parameters (laser fluence, pulse repetition frequency, number of shots per area, wall angle), to automatically generate Numerical Control (NC) part programs for the machine controller. The performance of the system has been verified and demonstrated by machining a particle transportation device. The CAM tool simplifies part programming and replaces the tedious trial-and-error approach to creating programs. The simulator tool accepts manual or computer generated part programs, and displays the tool path and the machined structure. This enables error checking and editing of the program before machining, and development of programs for complex microstructures. Combined, the tools provide a user-friendly CAD/CAM system environment for rapid prototyping of microfluidic devices.

• Journal of Korea Multimedia Society
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• v.13 no.3
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• pp.359-368
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• 2010

Algorithm visualization is useful for program testing, debugging and evaluating, as well as visual aids in education. When teaching algorithms and data structures, showing exact behaviors by graphics or animation is more suitable than just explaining them. Current systems for algorithm animation are limited to a couple of specific applications and need a special environment. In the proposed system, programmer writes source program in C and animator embeds visualization scripts in the appropriate location of the program. Then user can get an animation code in form of SVG and see a graphical representation on the web browser. Generated SVG animation code is platform independent and can also interact with other XML applications or HTML.

• Korean Journal of Microbiology
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• v.38 no.4
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• pp.267-275
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• 2002

We have developed GComp as an analysis tool for microbial genome comparison. This tool exploits BLAST or FASTA as a preprocessing program for local alignments to detect homologous regions, parses the homology search results, and generates tables and files to show homology relationship between two genomes at a glance. The interface for graphical representation of the comparative genomic analysis has been also implemented. Our test cases shows that the program can be useful in practice for intuitive and quantitative comparison of microbial genome sequence pairs as well as self-genome analysis. A few additional features have been devised and designed, which will be added in the further development.