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Improvement of early prediction performance of under-performing students using anomaly data (이상 데이터를 활용한 성과부진학생의 조기예측성능 향상)

  • Hwang, Chul-Hyun
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.26 no.11
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    • pp.1608-1614
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    • 2022
  • As competition between universities intensifies due to the recent decrease in the number of students, it is recognized as an essential task of universities to predict students who are underperforming at an early stage and to make various efforts to prevent dropouts. For this, a high-performance model that accurately predicts student performance is essential. This paper proposes a method to improve prediction performance by removing or amplifying abnormal data in a classification prediction model for identifying underperforming students. Existing anomaly data processing methods have mainly focused on deleting or ignoring data, but this paper presents a criterion to distinguish noise from change indicators, and contributes to improving the performance of predictive models by deleting or amplifying data. In an experiment using open learning performance data for verification of the proposed method, we found a number of cases in which the proposed method can improve classification performance compared to the existing method.

The Investigation of Analytical Techniques for Insulation Characteristics of Oil-Filled Transmission Cables (송전용 OF 케이블의 절연특성 분석방법에 대한 고찰)

  • Kim, Jong-Eun;Suh, Kwang-S.;Kim, Jung-Tae;Lee, Jun-Sun;Koo, Ja-Yoon
    • Proceedings of the KIEE Conference
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    • 1999.07d
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    • pp.1608-1610
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    • 1999
  • To find effective diagnostic method for Transmission OF cables, various characterizations were carried such as DGA (dissolved gas analysis), water contents, total acidity and AC breakdown voltage. It was found that the result was varied by sampling and container. The results from those characterization method showed the present condition and history very well and could be used to estimate the degree of degradation of cables.

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Sensitivity dependence on the effective surface area for cholesterol biosensor fabricated by silanization process (실란화 공정으로 제작된 콜레스테롤 센서의 전극 표면적에 따른 감도 특성)

  • Song, M.J.;Yoon, D.H.;Jin, J.H.;Min, N.K.;Hong, S.I.
    • Proceedings of the KIEE Conference
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    • 2004.07c
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    • pp.2114-2116
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    • 2004
  • 센서의 소형화 되는 추세에 전극 면적은 sensitivity의 중요한 요인이다. 본 연구에서는 콜레스테롤을 측정하기 위해 각각 planar 전극과 porous 전극에 효소 고정화 방법으로 covalent binding인 silanization 공정을 이용하여 전극 면적에 따른 전기화학적 감도를 비교하였다. Handles-Sevcik equation을 이용하여 전극 면적을 구한 결과 planar 전극의 경우 0.1608 $cm^2$, porous 전극의 경우 0.5054 $cm^2$로 porous 전극 면적이 planar전극에 비해 약 3.1배 증가하였다. 또, planar 센서의 sensitivity는 0.08567 ${\mu}A/mM{\cdot}cm^2$이고 porous 센서의 sensitivity는 planar sensor에 비해 약 3.1배 증가한 0.2656 ${\mu}A/mM{\cdot}cm^2$였다. 따라서 porous sensor의 sensitivity의 증가는 전극 면적의 증가에 따른 것이라고 할 수 있다.

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Optimal Sliding Mode Control of Anti-Lock Braking System

  • Ebrahimirad, H.;Yazdanpanah, M. J.;Kazemi, R.
    • 제어로봇시스템학회:학술대회논문집
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    • 2004.08a
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    • pp.1608-1611
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    • 2004
  • Anti-lock brake systems (ABS) are being increasingly used in a wide range of applications due to safety. This paper deals with a high performance optimal sliding mode controller for slip-ratio control in the ABS. In this approach a sliding surface square is considered as an appropriate cost function. The optimum brake torque as a system input is determined by minimizing the cost function and used in the controller. Simulation results reveal the effectiveness of the proposed sliding mode controller.

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Analysis of Internal Loading for Triple Manipulator Robotics

  • Chung, Jae-Heon;Yi, Byung-Ju;Kim, Whee-Kuk
    • 제어로봇시스템학회:학술대회논문집
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    • 2003.10a
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    • pp.1603-1608
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    • 2003
  • Multiple robotics systems with several sub-chains have a characteristic that grasp a common object with internal loading not to loose the grip. The investigation for the internal loading of a triple manipulator has been few as compared to a dual manipulator. In this paper, type of the internal loading for a triple manipulator system is investigated through analysis of the null space of the system. Several types of the internal loading are shown for general planar and spatial type triple robots, which rigidly grasp the common object. The general scheme is applied to analysis of the internal loading for the three-fingered and three-legged robots having a point contact with the grasped object.

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A Cloud Point Extraction-Spectrofluorimetric Method for Determination of Thiamine in Urine

  • Tabrizi, Ahad Bavili
    • Bulletin of the Korean Chemical Society
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    • v.27 no.10
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    • pp.1604-1608
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    • 2006
  • A simple and efficient cloud point extraction-spectrofluorimetric method for the determination of thiamine in human urine is proposed. The procedure is based on the oxidation of thiamine with ferricyanide to form thiochrome, its extraction to Triton X-114 micelles and spectrofluorimetric determination. The variables affecting oxidation of thiamine, extraction and phase separation were studied and optimized. Under the experimental conditions used, the calibration graphs were linear over the range 2.5-1000 ng $mL^{-1}$. The limit of detection was 0.78 ng $mL^{-1}$ of thiamine and the relative standard deviation for 5 replicate determinations of thiamine at 400 ng $mL^{-1}$ concentration level was 2.42%. Average recoveries between 93-107% were obtained for spiked samples. The proposed method was applied to the determination of thiamine in human urine.

A Study on Composition Model Design and Testing for EJB Design Pattern Based Bean Class (EJB Design Pattern 기반의 Bean Class 조립에 대한 모델 설계 및 Testing 에 관한 연구)

  • 신재준;이돈양;송영재
    • Proceedings of the IEEK Conference
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    • 2003.07d
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    • pp.1605-1608
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    • 2003
  • Today, E-Business develop because, Internet diffuse rapidly. Variety function and excellence performance needs for changeable user's requirement. So, EJB comes Component's addition and modify. For Component adds Function, Existing System modifies all of the source code. In EJB Component System, but, modifies simple source code. But, Today's System don't have cleary way that assembly component and design system. This Paper used design pattern for maintain of the component. this paper describes EJB Design Pattern using Abstract Factory Pattern. And EJB Component that used Pattern, decribes advantage and disavantage.

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熱線風速計에 의한 測定方法

  • 노병준
    • Journal of the KSME
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    • v.23 no.5
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    • pp.344-348
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    • 1983
  • 유속의 최초 측정방법은 Torricelli (1608-1647)가 Bernoulli 방정식을 오리피스에 적용하여 유속 계산식 v =k.root.2gh를 유도하였고, 그 이후 역시 Bernoulli 방정식을 이용하여 Henri Pitot (1695-1771)는 정체점에 대한 이론을 고려하여 정체압을 측정하는 방법으로 가는관을 이용하여 Seine 강의 유속을 측정하는데 성공하므로서 이론적인 유속계산식 v =k.root.2gh는 가장 원시적인 피토우관(Pito-tube) 이나 오리피스에 의한 유속계산식이지만, 현재에 아무리 전기적인 정밀측정 방법과 레이저에 의한 측정방법이 개발되어도 결국 피토우관에 의한 측정값이나 압력측정치와의 교정(Calibration)이 선행되지 않으면 안되기 때문에, 피토우관에 의한 측정방법은 가장 원시적 이면서 가장 정확한 측정방법의 하나이다. 다만 피토우관에 의한 측정은 속도장내의 평균속도를 측정하게 되고 난류성분의 해석이 불가능하며, 그 측정이 일차원 유동에 국한된다는 것이 단점 으로 되어 있다. 이러한 점들을 보완할 수 있는 측정장치 들이 많이 개발되고 있으나 본 해설 에서는 공기유동의 경우 우리가 가장 많이 사용하고 있는 열선풍속계에 대하여 그 용법을 논하기 로 한다.

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The Effect of Machinery House Location on the Stability of High Efficiency Gantry Crane (기계실 위치 변화가 고효율 갠트리 크레인의 안정성에 미치는 영향 분석)

  • Lee S.W.;Han G.J.;Shim J.J.;Han D.S.;Gwon S.G.;Kim T.H.
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2005.06a
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    • pp.1605-1608
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    • 2005
  • This study was carried out to analyze the effect of machinery house location on the stability of high efficiency gantry crane which can improve the productivity of the container transportation wok by reducing cycle time. The wind load was evaluated according to 'Load Criteria of Building Structures' enacted by the ministry of construction & transportation. The uplift forces of high efficiency gantry crane under this wind load were calculated by analyzing reaction forces at each supporting point. And variation of reaction forces at each supporting point was analyzed according to machinery house location.

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