• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 1999.03b
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• pp.49-52
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• 1999

Tailored-welded blanks are used for forming of automobile structural and skin components. Its main objective is to achieve weight and production cost reduction in manufacturing of the components. For successful application of tailored-welded blanks design of initial welded blanks and prediction of welding line movement are critical. Here the utilization of the backward tracing scheme of the finite element method shows to be desirable in design of initial welded blanks for net-shape production and in prediction of the welding line movement. First the design of initial blank in forming of welded thick sheet with isotropy is tried and it appears successful in obtaining a net-shape stamping product. Based in the first approach the backward tracing scheme is applied to anisotropic tailored blank. The welding line movement is also discussed.

• Journal of Global Scholars of Marketing Science
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• v.16 no.4
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• pp.1-11
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• 2006

Product quality of perishable food is significantly affected by the environment. Technological approaches for tracking and tracing such products have attracted increasing attentions in both research and practice. This paper studies how supermarket can maximize profits of selling perishable food through price adjustment based on real-ime product quality and values. This can be achieved by tracing the value of the perishable food based on an automatic product identification technology Radio Frequency Identification(RFID). With the support of the RFID, an optimization model can be developed to enable product tracking and tracing. The analysis of the model shows promising benefits of applying a dynamic pricing policy and obtains the optimal ordering decision in the respect of deterministic demand function.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.1 no.3
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• pp.21-26
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• 2008

In this paper, we extracted descending slope tracing waves (DSTW) and form factors (FF), and compared the detecting results of premature ventricular contraction (PVC) which were derived from DSTW and FF in order to find an efficient method. The 2nd. derivatives and DSTW were employed to extract correct R-waves from ECG. To evaluate extracting methods, ECGs including PVCs from MIT/BIH database were used.

• Journal of the Korea Institute of Military Science and Technology
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• v.9 no.2 s.25
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• pp.26-33
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• 2006

A sonar dome is basically designed and installed to protect sonar array from shocks, sea wave slaps and floating matters. The acoustic wave passing through sonar dome, however, can be distorted in magnitude and phase. This paper presents a numerical method for predicting the steady-state sound pressure on the surface of transducer array in the sonar dome and typical results of sonar beam pattern affected by sonar dome. A beam tracing model with phase information and a multi-layered elastic boundary model are involved. A full three-dimensional sonar dome is modeled as a GRP acoustic window, a rubber coated steel baffle and a rubber coated steel hull. A transducer array is modeled as thick steel cylinder. There are some assumptions such as incidence of plane wave, specular reflection on boundary and directionality of transducer element.

• Annual Conference on Human and Language Technology
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• 2023.10a
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• pp.672-676
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• 2023

지식 추적 (knowledge tacing)은 주어진 학습자의 과거 문제 해결 기록을 기반으로 학습자의 지식 습득 정도를 파악하여 목표 문제에 대한 정답 여부를 예측하는 것을 목표로 한다. 이전 연구에서는 이진 분류 기반의 모델을 사용하여 정답 유무만 예측하였기 때문에 학습자의 답변에 존재하는 정보를 활용하지 못한다. 최근 연구에서는 이를 생성 태스크로 변환하여 컴퓨터과학 분야에서 프로그래밍 질문에 대한 지식 추정을 수행하는 open-ended knowledge tracing (OKT)이 제안되었다. 하지만 최적의 OKT 모델에 대한 연구는 진행되지 않았으며 따라서 본 논문에서는 시간에 따라 변화하는 학습자의 지식 상태에 따라 답변 생성을 조정하는 새로운 OKT 방법론을 제안한다. 실험을 본 논문에서 제안하는 방법론의 우수성과 효율성을 증명한다.

• Journal of the Korean Society for Precision Engineering
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• v.16 no.10
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• pp.164-171
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• 1999

An optimum blank design technology is required for near-net of net-shape cold forming using sheets. Originally, the backward tracing scheme has been developed for preform design in bulk forming, and applied to several forming processes successfully. Its key concept is to trace backward from the final desirable configuration to an intermediate preform of initial blocker. A program for initial blank design in sheet forming which contains the capabilities of forward loading simulation by the finite element method and backward tracing simulation, has been developed and proved the effectiveness by applying to a square cup stamping process. In the blank design of square cup stamping, the backward tracing program can produce an optimum blank configuration which forms a sound net-shape cup product without machining after forming. Another general application appears in the blank design of a cup stamping with protruding flanges, one of typical automobile components. The blank configurations derived by backward tracing simulation have been confirmed by a series of loading simulations. The approach or decision of an initial blank configuration presented in this study will be a milestone in fields of sheet forming process design.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 1998.03a
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• pp.175-178
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• 1998

Tracings streamlines in global coordinate, especially with finite element mesh, requires much computation due to C0 continuity of velocity field. In this study, a new approach is presented for the determination of streamlines from velocity field obtained by FE analysis. It is shown that amount of calculation can be drastically reduced and boundary of element can be easily treated. The approach is applied to the problem of free surface of deforming workpieces in shape rolling.

• Journal of the Korean Society for Precision Engineering
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• v.26 no.11
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• pp.92-98
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• 2009

The scanning electron microscope (SEM) contains an electron optical system in which electrons are emitted and moved to form a focused beam, and generates secondary electrons from the specimen surfaces, eventually making an image. The electron optical system usually contains two condenser lenses and an objective lens. The condenser lenses generate a magnetic field that forces the electron beams to form crossovers at desired locations. The objective lens then focuses the electron beams on the specimen. The present study covers the design and analysis of an objective lens for a thermionic SEM. A finite element (FE) analysis for the objective lens is performed to analyze its magnetic characteristics for various lens designs. Relevant beam trajectories are also investigated by tracing the ray path of the electron beams under the magnetic fields inside the objective lens.

• Journal of the Semiconductor & Display Technology
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• v.16 no.4
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• pp.36-40
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• 2017

With an attempt to enhance the visibility of laser beam, we have investigated a black matrix with scattering particles by ray tracing simulations. As the scattering particle density is increased, the detected power by the receiver is increased, thereby enhancing the visibility. In reality, the visibility is reduced with increasing incident angle (away from the normal incidence) of laser beam, a phenomenon also observed by ray tracing simulations. It is due to the fact that the mean path is increased within a highly absorptive BM layer or a smaller number of rays hit the BM area when the incident angle is high. Embedding a number of scattering particles into BM may bring in crosstalk among pixels. However, it is negligible because scattered rays inside highly absorptive BM are re-scattered due to the high scattering particle density, decreasing the power of scattered rays into the active areas.

• International Journal of Computer Science & Network Security
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• v.24 no.6
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• pp.119-130
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• 2024

Universities are open systems that aim to prepare students to meet academic and industrial programs' expectations. It is important for universities to recognize these expectations and to make sure that they are achievable. To do so, graduates' progression tracking system is an essential tool for universities' development to ensure graduate students meet the market requirements. The purpose of this paper is to create automatic tracing system that captures information about students after graduation and creates annual report that represents the status of university students in term of employment or completing their study. It mainly assists graduates to find appropriate jobs that meet their desires or enabling them to complete their higher education by providing all these opportunities in one platform. The system main objective is to improve communication between graduate students, the university and companies. It also aims to identify the difficulties associated with graduate employability and changes are required to serve current students in term of creating new programs or activities. This helps universities to identify and address the existing curriculums and program's strengths and weaknesses and their adequacy, quality and competencies of a graduate in the labor market, which enhances the quality of higher education. we analyzed and implemented the tracing system using PHP language, which speeds up custom web application development and MySQL database, which guarantee data security, high performance, and other features. Graduate students found the proposed system usable and valuable.