• 제목/요약/키워드: Critical Science Research

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Effect of weak interlayer coupling on critical fluctuation in high $T_c$ superconductors

  • Kim, Jin-Tae;Kang, W.N.;Chung, S.H.;Ha, D.H.;Yoo, K.H.;Kim, M.S.;Lee, Sung-Ik;Park, Y.K.;Park, J.C.
    • Progress in Superconductivity
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    • 제1권1호
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    • pp.1-8
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    • 1999
  • The magnetization and/or resistivity of high $T_c$ superconductors ($YBa_2Cu_3O_{7-\delta}$(YBCO) single crystal, $Bi_2Sr_2CaCu_2O_8$ (Bi-2212) single crystal, $Tl_2Ba_2CaCu_2O_8$ (Tl-2212) film, $HgBa_2Ca_2Cu_3O_8$ (Hg-1223) film) have been measured as a function of magnetic field H and temperature T. The extracted fluctuation part of the magnetization and conductivity exhibits a critical behavior consistent with the three-dimensional XY model. The dynamic critical exponent z does not sensitively vary with a type of the superconductors. The value of z ranges from 1.5 to $1.8{\pm}0.1$. However, the static critical exponent ${\nu}$ is the most largely increased in Tl-2212 that has a weaker interlayer coupling strength than YBCO; the value of ${\nu}$ is 0.669, 0.909, 1.19, and 1.338 for YBCO, Bi-2212, Hg-1223, and Tl-2212 respectively. The results indicate that the weak interlayer coupling along the c-axis of high $T_c$ superconductors near $T_c$ does not influence the dynamic critical exponent z (the same value of superfluid $^4He$), but significantly increases the static critical exponent ${\nu}$.

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정보체계 탐구.평가의 철학적 분석 모델과 그 방법론적 활용: 비판 실재론적 접근 (A Study on the Philosophical Analysis Model and its Methodological Application of Information Systems Research.Evaluation - A Critical Realist Approach -)

  • 고창택
    • 한국정보시스템학회지:정보시스템연구
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    • 제16권4호
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    • pp.131-155
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    • 2007
  • The purpose of this thesis is to study on the philosophical analysis model and its methodological application of information systems research evaluation from critical realist perspective. Fist of all, I examine ontological epistemological methodological assertions of critical realism. Because the philosophy of critical realism is an opportunity for information systems study. I examine Dobson and Mutch's critical realist perspective on actors-structure model. I suggest a critical realist actors-praxis-structure model. This model provides the potential for a new approach to social investigations in its provision of an ontology for the analytical separation of structure and agency. Of most importance might be the incorporation of non-humans into the analysis of social interaction and of technology into the elaboration of structures. I also examine Tsoukas's critical realistic meta-theory of management. I suggest a critical realist IS management model. This model elucidate the nature of management and delineate the scope of applicability of various perspectives on management. The causal powers of management reside in the real domain and, taken together, their logics are contradictory, the effects of their contradictory composition are contingent upon prevailing contingencies. I analyze Carlsson's theory of design knowledge. His framework builds on that the aim of IS design science research is to develop practical knowledge for the design and realization of different classes of IS initiatives, where IS are viewed as socio-technical systems and not just IT artefacts. The framework proposes that the output of IS design science research is practical IS design knowledge in the form of field-tested and grounded technological rules. The IS design knowledge is developed through an IS design science research cycle. In conclusion, I think that IS actors-praxis-structure model, meta-theoretical IS management model, and IS design knowledge model according to critical realistic approach are very useful for IS research evaluation. Nevertheless, important problems are left not resolved.

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간호학적 비판적 사고능력에 대한 문헌고찰 (Critical Thinking in Nursing Science: A Literature Review)

  • 신수진;정덕유
    • 성인간호학회지
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    • 제21권1호
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    • pp.117-128
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    • 2009
  • Purpose: The purposes of this study were as follows; 1) To review the definitions of critical thinking from various perspectives, 2) To examine the critical thinking measurements throughout nursing research, and 3) To review the nursing studies with regard to critical thinking. Methods: This study was a literature review with regard to the critical thinking in nursing in aspects of conceptual meaning, measurements, and research. Results: The definition of critical thinking in nursing included decision making in clinical setting, inference with logical construct to increase nursing quality, interpretation in the context, and evaluation. The critical thinking was a core concept, which meant not only simple nursing process, but included decision making ability. The critical thinking has been conceptualized by both critical thinking disposition and skill. However, there was no nursing specified critical thinking measurement. Critical thinking research has been conducted to describe critical thinking disposition and critical thinking, to determine relationships between critical thinking and clinical competency, and to evaluate the effectiveness of educational programs. Conclusion: The instruments for measuring critical thinking disposition and skill that contain cultural difference and clinical specificity need to be developed to measure critical thinking and increase it.

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한국과 중국의 간호대학생들의 비판적 사고성향과 전문직관 비교연구 (Comparison of Critical Thinking and Professionalism between Korean and Chinese Nursing Students)

  • 이향련;김윤희;강현숙;이지아
    • 동서간호학연구지
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    • 제13권2호
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    • pp.179-186
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    • 2007
  • Purpose: The aim of this study was to examine the differences in critical thinking and professionalism between Korean and Chinese nursing students. Critical thinking and professionalism were a part of five domains to evaluate nursing education: critical thinking, professionalism, leadership, communication, and nursing practice from the Korean Accreditation Board of Nursing. Methods: Data were collected from 207 college nursing students: 104 students from the 4-year degree program in Korea and 103 from the 5-year degree program in China from September 2006 to September 2007. The instruments for Chinese students were translated in Chinese and re-translated to check accuracy. The data were analyzed by using the SPSS/PC+ Win 12.0 Version. The $x^2$-test to compare general characteristics and the t-test to examine the differences of the study variables were conducted. Results: Korean nursing students reported significantly higher scores of critical thinking than did Chinese students while Chinese students reported significantly higher scores of professionalism. Students took previous courses associated with critical thinking reported significantly higher scores than did those without previous courses taken. There was no significant difference in scores of professionalism whether students had previous experience of related courses or not. Rather than, students with clinical practice reported higher scores of professionalism than did those without clinical practice. Conclusion: Levels of critical thinking were influenced by course focusing on critical thinking while professionalism was improved by combination of associated courses and clinical practice. For follow-up study, there is needed to examine nursing curriculum between Korea and China.

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CRM 시스템 구현 성공 메커니즘에 관한 탐색적 연구 (A Study on the Mechanism Leading to the Success of CRM Systems Implementation)

  • 김희웅;곽기영
    • 한국경영과학회지
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    • 제29권1호
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    • pp.1-16
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    • 2004
  • Critical success factors (CSFs) have been replicated and applied in a wide variety of settings for more than two decades. Most previous research on CSF have focused on identifying critical factors, based on the variance theory, in terms of the correlation between individual factor and Information system (IS) success. However, it is unknown how a set of critical factors Influence each other and lead to IS success, which means the process of IS implementation. in this research, we aim to understand how a set of critical factors influence each other and lead to IS success in the context of IS implementation for Customer Relationship Management based on the process theory. This research has implications In explaining a mechanism leading to CRM systems success based on the influencial relationships among the critical factors.

Fabrication and statistical characterization of Nb SQUID sensors for multichannel SQUID system

  • Kim, B.K.;Yu, K.K.;Kim, J.M.;Kwon, H.;Lee, S.K.;Lee, Y.H.
    • 한국초전도ㆍ저온공학회논문지
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    • 제22권4호
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    • pp.62-66
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    • 2020
  • We fabricated superconducting quantum interference devices (SQUIDs) based on Nb Josephson junctions, and characterized the key parameters of the SQUIDs. The SQUIDs are double relaxation oscillation SQUIDs (DROSs) having larger flux-to-voltage transfer coefficient than the standard DC-SQUIDs. SQUID sensors were fabricated by using Nb junction technology consisted of a DC magnetron sputtering and a conventional photolithography process. In multichannel SQUID systems for whole-head magnetoencephalography measurement with a helmet-type SQUID array, we need about 336 SQUID sensors for each system. In this paper, we fabricated a few hundred SQUID sensors, measured the critical current, flux modulation voltage and decided if each tested SQUID can be used for the multichannel systems. As the criterion for the acceptance of the sensors, we chose the critical current and amplitude of the modulation voltage to be 8 ㎂ and 80 ㎶, respectively. The average critical current of the SQUIDs was 10.58 ㎂. The typical flux noise of the SQUIDs with input coil shorted was 2 μΦ0/√Hz at white region.