• Title/Summary/Keyword: self-limiting

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

  • Ha, Minsu
    • Journal of The Korean Association For Science Education
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    • v.36 no.6
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    • pp.935-946
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    • 2016
  • This study aims to explore cognitive biases relating the core competences of science and instructional strategy in reducing the level of cognitive biases. The literature review method was used to explore cognitive biases and science education experts discussed the relevance of cognitive biases to science education. Twenty nine cognitive biases were categorized into five groups (limiting rational causal inference, limiting diverse information search, limiting self-regulated learning, limiting self-directed decision making, and category-limited thinking). The cognitive biases in limiting rational causal inference group are teleological thinking, availability heuristic, illusory correlation, and clustering illusion. The cognitive biases in limiting diverse information search group are selective perception, experimenter bias, confirmation bias, mere thought effect, attentional bias, belief bias, pragmatic fallacy, functional fixedness, and framing effect. The cognitive biases in limiting self-regulated learning group are overconfidence bias, better-than-average bias, planning fallacy, fundamental attribution error, Dunning-Kruger effect, hindsight bias, and blind-spot bias. The cognitive biases in limiting self-directed decision-making group are acquiescence effect, bandwagon effect, group-think, appeal to authority bias, and information bias. Lastly, the cognitive biases in category-limited thinking group are psychological essentialism, stereotyping, anthropomorphism, and outgroup homogeneity bias. The instructional strategy to reduce the level of cognitive biases is disused based on the psychological characters of cognitive biases reviewed in this study and related science education methods.

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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    • v.26 no.1
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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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    • v.8 no.5
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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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    • v.14 no.4
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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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    • v.15 no.2
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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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Management of Temporomandibular disorder (측두하악장애의 치료)

  • Jung, Da-Woon;Chung, A-Young;Kim, Seong-Taek
    • Journal of Dental Rehabilitation and Applied Science
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    • v.28 no.4
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    • pp.441-452
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    • 2012
  • Most of signs and symptoms of temporomandibular disorder(TMD) is temporary and self-limiting as other musculoskeletal diseases. Conservative, reversible treatment; self care, behavior modification, physical therapy, pharmacotherapy, splint therapy should be considered as initial treatment for temporomandibular disorder rather than non conservative, irreversible treatment.

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

  • Heo, Soung-Ouk;Kim, Tae-Min;Han, Byung-Sung;Du, Ho-Ik
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.26 no.12
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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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    • v.6 no.1
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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.

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

  • Kim, Tae-Min;Hong, Gong-Hyun;Han, Byung-Sung;Du, Ho-Ik
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.28 no.3
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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.

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

  • Choi, Hyo-Sang
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.17 no.6
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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.