• 제목/요약/키워드: self-limiting

검색결과 235건 처리시간 0.019초

합리적 문제해결을 저해하는 인지편향과 과학교육을 통한 탈인지편향 방법 탐색 (Exploring Cognitive Biases Limiting Rational Problem Solving and Debiasing Methods Using Science Education)

  • 하민수
    • 한국과학교육학회지
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    • 제36권6호
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    • pp.935-946
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    • 2016
  • 이 연구의 목적은 과학교육과 관련된 인지편향을 확인하고 과학교육을 통하여 인지편향을 줄일 수 있는 방법을 확인하기 위하여 계획되었다. 문헌조사를 통하여 연구되어진 인지편향을 수집하였고, 과학학습의 관련성이 높은 인지편향을 과학교육전문가와의 토론을 통하여 추출하였다. 연구 결과 합리적 인과관계추론을 방해하는 인지편향, 다양한 정보와 결론 생성을 방해하는 인지편향, 자기반성적 학습을 방해하는 인지편향, 자기 주도적 의사결정을 방해하는 인지편향, 범주 제한적 사고를 조장하는 인지편향의 다섯 가지로 분류하였고, 총 29개의 인지편향들을 조사하였다. 합리적 인과관계추론의 방해하는 인지편향은 목적론적 사고, 가용성 편향, 착각적 상관, 클러스터 착각이었다. 문제해결에서 다양한 정보의 탐색을 방해하는 인지편향은 선택적 지각, 실험자 편향, 확증편향, 단순 사고 효과, 주의 편향, 신념편향, 실용 오류, 기능적 고착, 틀 효과가 있었다. 자기반성적 학습을 방해하는 인지편향은 과도한 자신감 편향, 우월성 편향, 계획 오류, 기본적 귀인 오류, 더닝-크루거 효과, 사후확신편향, 맹점편향을 확인하였다. 자기 주도적 의사결정을 방해하는 인지편향은 동조효과, 편승효과, 집단사고, 권위에 호소, 정보편향이 있다. 마지막으로 범주 제한적 사고를 조장하는 인지편향으로는 심리학적 본질주의, 고정관념, 의인화, 외집단 동질성 편향이 있었다. 연구된 인지편향에 대한 심리학적 특징들과 과학교수-학습방법들을 토대로 인지편향을 줄이고 역량을 향상시킬 수 있는 수업 방법에 대해서 논의한다.

Effect of Island Size on the Packing Density in the Early Stages of Alkylsilane-Based Monolayer Self Assembly

  • Lee, Bo-H.;Sung, Myung-M.
    • Bulletin of the Korean Chemical Society
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    • 제26권1호
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    • pp.127-130
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    • 2005
  • The early stage of the self assembly for octadecyltrichlorosilane (OTS)-based monolayers is investigated using atomic force microscopy (AFM). Height measurements using AFM prove that the island height of the monolayers gradually increases with increasing the island size, and is close to the limiting value (h = $\sim$25 $\AA$) after d = $\sim$600 nm in size. Since the theoretical length of a covalently bound OTS molecule is 26.2 Å, the limiting value of the island height means that the islands with d ${\geq}$ 600 nm consist of close-packed, fully extended chains. The heights for the islands with d < 600 nm are lower than the limiting value and decrease with decreasing the island sizes. This observation indicates that the OTS molecules in the small islands are less densely packed, and that the packing densities of the islands increase as the islands grow in size.

Comparative Study of Current Limiting Characteristics for Hybrid Type and Flux-Lock Type SFCLs

  • Lim, Sung-Hun
    • Transactions on Electrical and Electronic Materials
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    • 제8권5호
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    • pp.222-225
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    • 2007
  • In this paper, we compared the current limiting characteristics of both the hybrid type and the flux-lock type superconducting fault current limiters(SFCLs), which have a magnetic coupling structure between a primary winding and several secondary windings. The limiting impedances of two SFCLs were derived from each equivalent circuit considering the design parameters of SFCL such as the self-inductance of secondary winding and the resistance of $high-T_C$ superconducting(HTSC) element. Through the comparison for the limiting impedances of two SFCLs considering the dependence of the HTSC element's resistance on the applying voltage into the SFCL, the hybrid type SFCL was confirmed to have larger limiting impedance with smaller resistance of HTSC element than the flux-lock type SFCL. It was expected from the analysis that the hybrid type SFCL was more advantageous than the flux-lock type SFCL from the viewpoint of the fault current limiting level.

The Rao-Robson Chi-Squared Test for Multivariate Structure

  • Park, Cheol-Yong
    • Journal of the Korean Data and Information Science Society
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    • 제14권4호
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    • pp.1013-1021
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    • 2003
  • Huffer and Park (2002) proposed a chi-squared test for multivariate structure. Their test detects the deviation of data from mutual independence or multivariate normality. We will compute the Rao-Robson chi-squared version of the test, which is easy to apply in practice since it has a limiting chi-squared distribution. We will provide a self-contained argument that it has a limiting chi-squared distribution. We study the accuracy in finite samples of the limiting distribution. We finally compare the power of our test with those of other popular normality tests in an application to a real data.

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A Note on the Simple Chi-Squared Test of Multivariate Normality

  • Park, Cheol-Yong
    • Journal of the Korean Data and Information Science Society
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    • 제15권2호
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    • pp.423-430
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    • 2004
  • We provide the exact form of a Rao-Robson version of the chi-squared test of multivariate normality suggested by Park(2001). This test is easy to apply in practice since it is easily computed and has a limiting chi-squared distribution under multivariate normality. A self-contained formal argument is provided that it has the limiting chi-squared distribution. A simulation study is provided to study the accuracy, in finite samples, of the limiting distribution. Finally, a simulation study in a nonnormal distribution is conducted in order to compare the power of our test with those of other popular normality tests.

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측두하악장애의 치료 (Management of Temporomandibular disorder)

  • 정다운;정아영;김성택
    • 구강회복응용과학지
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    • 제28권4호
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    • pp.441-452
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    • 2012
  • 다른 근골격성 질환에서와 같이, 측두하악장애의 징후와 증상은 일시적이거나 자기 한정적(self-limiting)인 경우가 많다. 따라서 복잡한 교합 치료나 수술과 같은 비보존적, 비가역적 치료를 초기치료로 선택하는 것은 가급적 피해야 한다. 또한 자가요법, 행동 수정, 물리치료, 약물요법, 장치치료 등과 같은 보존적, 가역적 치료가 측두하악장애의 초기치료로 추천된다.

사고전류 제한형 초전도케이블 제작을 위한 초전도 선재 선정에 관한 연구 (Study on Selection of HTS Wire for Fabrication of Fault Current-limiting Type HTS Cables)

  • 허성욱;김태민;한병성;두호익
    • 한국전기전자재료학회논문지
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    • 제26권12호
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    • pp.904-908
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    • 2013
  • When an abnormal condition occurs due to a fault current at a consumer location where electricity is supplied through a high-capacity and high-$T_c$ superconducting(HTS) cable, the HTS cable would be damaged if there is no appropriate measure to protect it. Therefore, appropriate measures are needed to protect HTS cables. The fault-current-limiting HTS cable that was suggested in this study performs an ideal transport current function in normal operations and plays a role in limiting a fault current in abnormal operation (i.e., when a fault current is applied). It has a structure that facilitated its self-current-limiting ability through device change and reconfiguration in the existing HTS cable without extra switching equipment. To complete this structure, it is essential to investigate about the selection of the superconducting wire. Therefore, in this paper, HTS wire using two types of different stabilization layer is compared and examined the stability and current limiting properties under the existence of a fault current.

Partially-insulated MOSFET (PiFET) and Its Application to DRAM Cell Transistor

  • Oh, Chang-Woo;Kim, Sung-Hwan;Yeo, Kyoung-Hwan;Kim, Sung-Min;Kim, Min-Sang;Choe, Jeong-Dong;Kim, Dong-Won;Park, Dong-Gun
    • JSTS:Journal of Semiconductor Technology and Science
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    • 제6권1호
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    • pp.30-37
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    • 2006
  • In this article, we evaluated the structural merits and the validity of a partially insulated MOSFET (PiFET) through the fabrication of prototype transistors and an 80 nm 512M DDR DRAM with partially-insulated cell array transistors (PiCATs). The PiFETs showed the outstanding short channel effect immunity and off-current characteristics over the conventional MOSFET, resulting from self-induced halo region, self-limiting SID shallow junction, and reduced junction area due to PiOX layer formation. The DRAM with PiCATs also showed excellent data retention time. Thus, the PiFET can be a promising alternative for ultimate scaling of planar MOSFET.

사고전류 제한형 고온 초전도케이블의 한류부 특성평가 (Evaluation on the Properties of the Current Limiting Part for Fault-Current-Limiting Type HTS Cables)

  • 김태민;홍공현;한병성;두호익
    • 한국전기전자재료학회논문지
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    • 제28권3호
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    • pp.191-195
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    • 2015
  • Inside the existing superconducting cables, the superconducting wire carries a loss-free current, and the cable former (the stranded copper wire) bypasses the fault current to prevent damage and loss of the superconducting cable when the fault current is applied. The fault-current-limiting-type superconducting cable proposed in this paper usually carries a steady current; but in a fault state, the cable generates self-resistance that makes the fault current lower than a certain width. That is, the superconducting cable that transmitted only a low voltage and a large capacity power repetitively limits the fault current, as does a superconducting current limiter. To complete this structure, it is essential to investigate the mutual resistance relationship between the superconducting wires after applying a fault current. Therefore, in this paper, one kinds of superconducting wires (a wire without a stabilization layer) were connected parallel 4 tapes, respectively; and after applying a fault current, the current, voltage, resistance and thermal stability of the HTS thin-film wires were examined.

고온 초전도 퓨즈의 한류 및 방전 특성 (Current Limiting and Discharge Characteristics of High Tc Superconductive Fuse)

  • 최효상
    • 한국전기전자재료학회논문지
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    • 제17권6호
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    • pp.673-677
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    • 2004
  • We present the basic properties of a superconductive fuse (SF) based on YBCO/Au films. The SF consists of YBCO stripes covered with Au layers for current shunt. The fault current was limited to a designed value in less than 0.4 msec by resistance development in YBCO/Au upon quenching. This enabled the SF to transfer small fault power and the suppressed current was sustained for more than 0.5 msec while Au layer melting and arcing. The arcing time was less than 2.5 msec, that is short enough to do self-interruption. Under the source voltage of 100 $V_{rms}$, the longer the duration time of fault current was, the shorter its discharge time was. The duration time of fault current and its discharge time were reduced by increased voltages in the range of 200 - 300 $V_{rms}$. We thought that this was because the quench propagation was limited by local melting generated with higher voltage.age.