• Title/Summary/Keyword: Critical Theory

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c-axis Tunneling in Intercalated Bi$_2Sr_2CaCu_2O_{8+x}$ Single Crystals

  • Lee, Min-Hyea;Chang, Hyun-Sik;Doh, Yong-Joo;Lee, Hu-Jong;Lee, Woo;Choy, Jin-Ho
    • 한국초전도학회:학술대회논문집
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    • v.9
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    • pp.260-260
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    • 1999
  • We compared c-axis tunneling characteristics of small stacked intrinsic Josephson junctions prepared on the surface of pristine, I-, and HgI$_2$-intercalated Bi$_2Sr_2CaCu_2O_{8+x}$ (Bi2212) single crystals. The R(T) curves are almost metallic in I-Bi2212 specimens, but semiconducting in HgI$_2$-Bi2212 ones.· The transition temperatures were 82.0 K, 73.0 K, and 76.8 K for pristine Bi2212, I-Bi2212, and HgI2-Bi2212 specimens, respectively, consistent with p-T$_c$ phase diagram. Current-voltage (IV) characteristics of both kinds of specimens show multiple quasiparticle branches with well developed gap features, indicating Josephson coupling is established between neighboring CuO$_2$ planes. The critical current I$_c$ of I-Bi2212 is almost the same as of that of pristine crystals, but I$_c$ is much reduced in Hgl$_2$-Bi2212. In spite of expanded interlayer distances, the interlayer coupling is not significantly affected in I-Bi2212due to holes generated by iodine atoms. The coupling in HgI$_2$-Bi2212 is, however, weakened due to inertness of HgI$_2$ molecules and the expansion of interlayer distance. Relation between the superconducting transition temperature T$_c$ and the critical current I$_c$ seems to contradict Anderson's interlayer-pair-tunneling theory but agree with a modified version of it.

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An Action Research for Reflective Practice of Home Economics Teacher through Professional Learning Community Activity (교사학습공동체 활동을 통한 가정과 교사의 성찰적 실천에 대한 실행연구)

  • Lee, Gyeongsuk;Yoo, Taemyung
    • Human Ecology Research
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    • v.54 no.4
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    • pp.365-384
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    • 2016
  • The purpose of this research is to apprehend what the power of professional learning community (PLC) to make home economics teachers participate is and how PLC activity contributes to reflective practice and change of participating home economics teachers by experiencing reflective practices. For this, self-reflective action research of Kemmis and McTaggart was conducted. Six home economics teachers participated voluntarily and totally 18 PLC sessions from May 31, 2013 to May 19, 2014 were held. Two themes of 'looking in classes' as a main practice theme and 'designing classes together' as a supporting theme were carried. Findings and conclusions of this study are as following. First, participants of PLC to get data and information on teaching and to solve problems with fellow teachers for better classes at first. However, they have become to comfort and sympathize each other about difficulties in school as home economics teachers. Second, through the PLC activity, they found they had uncomfortable belief about teaching and tried to practice solutions by critical and reflective thinking. Third, they put efforts in finding alternative framework of looking inside their classes for the fundamental improvement in teaching. For this, they formulated questionnaire to describe their own reflective practice through the alternative framework from a critical perspective in teaching, a view of student's learning, and a teacher's inner view for improvement of practice. Fourth, PLC activity for a year allowed them to combine theory and reality though reflective process by designing classes together and reflectively practicing them in classes.

A Comparative Analysis on Policy Evaluation Methods: Focused on Fair Labeling & Advertising Act (정책평가방법의 비교분석: 표시.광고규제를 중심으로)

  • Choi, Shin-Ae;Yeo, Jung-Sung
    • Survey Research
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    • v.11 no.3
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    • pp.57-79
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    • 2010
  • This study evaluated the policy performance of i) Public Notice of Critical Information, ii) Substantiation of Facts in Labeling and Advertising, iii) Temporary Injunctions, and iv) Advertisement Correcting Misrepresented Facts, which were main policies belonged to Fair Labeling and Advertising Act(hereinafter referred to as "FLA Act"). The data was collected by visiting 76 persons personally, who were consumer policy and law experts, labeling and advertising staffs of corporations, and persons in charge of policies including public officials dealing with consumer policies at Korea Fair Trade Commission, while using a structured questionnaire at the same time. The survey was performed to examine the general policy performance and evaluation the results of FLA Act by evaluation methods. The results of the analysis are comprehensively summarized as follows. There were differences in the ranking of policies evaluated by labeling and advertising staffs of corporations and persons in charge of policies according to evaluation methods, and, in Simple Evaluation, higher scores were gained compared to Weighted Evaluation which reflected weighted values or Fuzzy Evaluation. The result shows that evaluation results can vary in policy performance evaluation according to evaluation methods.

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A Landscape Design of Eunpyeong New Town District 2, Seoul (서울 은평 뉴타운 2지구 조경설계)

  • Ahn Gye-Dong;Choi Jung-Min
    • Journal of the Korean Institute of Landscape Architecture
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    • v.33 no.4 s.111
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    • pp.143-154
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    • 2005
  • The Seoul Housing Corporation pronounced a design competition for Eunpyeng New Town District 2 in March of 2005. The authors collaborated on this design and won rot prize. Design guidelines of this competition were to make environmentally sustainable design, to develop as a resort site and cultural place for everyday life of residents, to link with green fabric of the district, and to elevate positive image and identity of Eunpyeng New Town district by creating a attractive landscape. The authors developed design concept and strategy within the guidelines and site conditions. The environmental setting of this site was characterized by mountain to the rear of the site with a stream passing through the district and the front of the site. This is the most important condition for the location principle of residence in Fung Shui theory. Therefore, the schema of the design was introduced by Fung Shui and Chi of place. To evolve design concept, we reinterpret the Fung Shui and Chi in the site combining with modem landscape design strategy, so that good place making could bring about well-being life of residents. By doing that, design concept of the proposal evolved as follows: 'fullness of comfortable life', 'adaptation of nature', 'inspiration of natural force'. This design approach is critical reevaluation of regional characters employing modem strategy. It is a conscious strategy of critical regionalism as distinguished from the traditional site oriented approach. The following are some of the major features in the design: green network and water recycle system in the site, promenade of forest with the experience nature, link to community core, theme gardens with plants having strong fragrances, terrace gardens with different level of housing type, playgrounds and resting places with many types, human scale facilities for residents.

Situating the Subject within the Global Material Conditions -A Critical Review on the Theorization of Postcolonial Ideas (지구화 시기 주체 구성의 물적 토대 복원을 위한 시론 -포스트식민주의 이론화 과정에 대한 리뷰를 중심으로)

  • Kim, Sumi
    • Korean journal of communication and information
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    • v.70
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    • pp.66-94
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    • 2015
  • Postcolonialism, as a school of thought, has become enormously influential for understanding the recent phenomena of globalization. While rejecting the universalizing categories of the Enlightenment, postcolonialism has called into question the old idea of culture and identity as a transcendent regime of authenticity and purity. It has also celebrated the diasporic experiences that entail porous and hybrid cultural identities as a potential site of struggle and resistance against the dominant cultural and discursive order. It is argued, however, that postcolonial theory's emancipatory claims relating to the diversified global culture tend to be complicit with transnational capitalism that brings about global issues of material as well as cultural injustice. This article, through a thorough review of the ways the postcolonial theoretical framework has been developed and appropriated by main figures in postcolonial scholarship, seeks for a theoretical and critical strategy to grasp the complex conditions of global inequality.

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Theoretical Background and Critical Discussion about Securitzation Trend of Cyber Threat (사이버 위협의 안보화 동향에 대한 이론적 배경과 비판적 논의)

  • Lee, Kwangho;Lee, Swengkyu;Kim, Hokil
    • Convergence Security Journal
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    • v.19 no.5
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    • pp.99-105
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    • 2019
  • In this study present the theoretical background and major trends in which cyber threats are securitization through the discourse process. In particular, this study explained based on the theory of Copenhagen school, which is critical of the security of cyber threats. And presented the security of non-traditional threats and the security of emerging security issues, which explained the process of security for cyber threats, based on existing research, and explained the limitations to this. And tried to provide a cautious point of view that the militarization phenomenon of cyber threats that is currently displayed is a phenomenon that is displayed through the combination of technical discourse and military discourse. Through this study, we aim to show the military the limits of universal solution presentation and the borderline perspective of militarization based on objective insights into the cyber threat security process.

The Effects of an Advanced Cardiac Life Support Simulation Training Based on the Mastery Learning Model (완전학습 모델을 기반으로 한 시뮬레이션 훈련이 전문심장소생술 습득에 미치는 효과)

  • Kwon, Eun Ok;Shim, Mi Young;Choi, Eun Ha;Lim, Sang Hee;Han, Kyoung Min;Lee, Eun Joon;Chang, Sun Ju;Lee, Mi Mi
    • Journal of Korean Clinical Nursing Research
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    • v.18 no.1
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    • pp.126-135
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    • 2012
  • Purpose: This study was aimed to develop a simulation training program of an advanced cardiac life support (ACLS) based on the mastery learning model (Simulation-MLM), and evaluate the effects of the program on critical care nurses. Methods: As an experimental pre-post test with a non-equivalent control group, the study employed convenience sampling of 38 critical care nurses. The experimental group received the Simulation-MLM including a theoretical lecture, formative evaluation, and simulation training, whereas only a theoretical lecture for the control group. The knowledge, self-efficacy, and performance degrees of respondents were measured to verify the effects of the Simulation-MLM. The statistical processing of the collected data utilized the SPSS WIN 17.0 program. Results: After receiving Simulation-MLM, the participants in the experimental group reported higher marks in the knowledge, self-efficacy and performance of ACLS compared with those in the control group. However, both experimental and control groups demonstrated no significant differences in knowledge, self-efficacy and performance. Conclusion: Despite of the limitation of a small sample size, this study was considered meaningful in a sense that it showed a venue for improving ACLS training efficiency. Future research with more distinct treatment differentiation and better adequate outcome variables was warranted in order to prove the effects of a theory-based simulation education.

A Study on the Improvement of Plastic Boat Manufacturing Process Using TOC & Statistical Analysis (TOC와 통계적 분석에 의한 플라스틱보트 제조공정 개선에 관한 연구)

  • Yoon, Gun-Gu;Kim, Tae-Gu;Lee, Dong-Hyung
    • Journal of Korean Society of Industrial and Systems Engineering
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    • v.39 no.1
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    • pp.130-139
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    • 2016
  • The purpose of this paper is to analyze the problems and the sources of defective products and draw improvement plans in a small plastic boat manufacturing process using TOC (Theory Of Constraints) and statistical analysis. TOC is a methodology to present a scheme for optimization of production process by finding the CCR (Capacity Constraints Resource) in the organization or the all production process through the concentration improvement activity. In this paper, we found and reformed constraints and bottlenecks in plastic boat manufacturing process in the target company for less defect ratio and production cost by applying DBR (Drum, Buffer, Rope) scheduling. And we set the threshold values for the critical process variables using statistical analysis. The result can be summarized as follows. First, CCRs in inventory control, material mix, and oven setting were found and solutions were suggested by applying DBR method. Second, the logical thinking process was utilized to find core conflict factors and draw solutions. Third, to specify the solution plan, experiment data were statistically analyzed. Data were collected from the daily journal addressing the details of 96 products such as temperature, humidity, duration and temperature of heating process, rotation speed, duration time of cooling, and the temperature of removal process. Basic statistics and logistic regression analysis were conducted with the defection as the dependent variable. Finally, critical values for major processes were proposed based on the analysis. This paper has a practical importance in contribution to the quality level of the target company through theoretical approach, TOC, and statistical analysis. However, limited number of data might depreciate the significance of the analysis and therefore it will be interesting further research direction to specify the significant manufacturing conditions across different products and processes.

Post buckling mechanics and strength of cold-formed steel columns exhibiting Local-Distortional interaction mode failure

  • Muthuraj, Hareesh;Sekar, S.K.;Mahendran, Mahen;Deepak, O.P.
    • Structural Engineering and Mechanics
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    • v.64 no.5
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    • pp.621-640
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    • 2017
  • This paper reports the numerical investigation conducted to study the influence of Local-Distortional (L-D) interaction mode buckling on post buckling strength erosion in fixed ended lipped channel cold formed steel columns. This investigation comprises of 81 column sections with various geometries and yield stresses that are carefully chosen to cover wide range of strength related parametric ratios like (i) distortional to local critical buckling stress ratio ($0.91{\leq}F_{CRD}/F_{CRL}{\leq}4.05$) (ii) non dimensional local slenderness ratio ($0.88{\leq}{\lambda}_L{\leq}3.54$) (iii) non-dimensional distortional slenderness ratio ($0.68{\leq}{\lambda}_D{\leq}3.23$) and (iv) yield to non-critical buckling stress ratio (0.45 to 10.4). The numerical investigation is carried out by conducting linear and non-linear shell finite element analysis (SFEA) using ABAQUS software. The non-linear SFEA includes both geometry and material non-linearity. The numerical results obtained are deeply analysed to understand the post buckling mechanics, failure modes and ultimate strength that are influenced by L-D interaction with respect to strength related parametric ratios. The ultimate strength data obtained from numerical analysis are compared with (i) the experimental tests data concerning L-D interaction mode buckling reported by other researchers (ii) column strength predicted by Direct Strength Method (DSM) column strength curves for local and distortional buckling specified in AISI S-100 (iii) strength predicted by available DSM based approaches that includes L-D interaction mode failure. The role of flange width to web depth ratio on post buckling strength erosion is reported. Then the paper concludes with merits and limitations of codified DSM and available DSM based approaches on accurate failure strength prediction.

Study on Plugging Criteria for Thru-wall Axial Crack in Roll Transition Zone of Steam Generator Tube (증기발생기 전열관 확관천이부위 축방향 관통균열의 관막음 기준에 관한 연구)

  • Park, Myeong-Gyu;Kim, Yeong-Jong;Jeon, Jang-Hwan;Kim, Jong-Min;Park, Jun-Su
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.20 no.9
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    • pp.2894-2900
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    • 1996
  • The stream generator tubes represent an integral part of a major barrier against the fission product release to the environment. So, the rupture of these tubes could permit flow of reactor coolant into the secondary system and injure the safety of reactor coolant system. Therefore, if the crack was detected during In-Service Inspection of tubes the cracked tube should be evaluated by the pulgging criteria and plugged or not. In this study, the fracture mechanics evaluation is carried out on the thru-wall axial crack due to Primary Water Stress Corrosion Cracking in the roll transition aone of steam generator tube to help the assurence the integrity of tubes and estabilish the plugging criteria. Due to the Inconel which is used as tube material is more ductile than others, the plastic instability repture theory was used to calculate the critical and allowable crack length. Based on Leak Before Break concept the leak rate for the critical crack length and the allowable leak rate are compared and the safety of tubes was given.