• Title/Summary/Keyword: J-$A_2$Theory

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A Qualitative Case Study of an Exemplary Science Teacher's Earth Systems Education Experiences

  • Lee, Hyon-Yong
    • Journal of the Korean earth science society
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    • v.31 no.5
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    • pp.500-520
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    • 2010
  • The purposes of this case study were (1) to explore one experienced teacher's views on Earth Systems Education and (2) to describe and document the characteristics of the Earth Systems Education (ESE) curriculum provided by an exemplary middle school science teacher, Dr. J. All the essential pieces of evidence were collected from observations, interviews with the experienced teacher and his eighth grade students, informal conversations, document analysis, and field notes. The $NUD^*IST$ for MS Windows was used for an initial data reduction process and to narrow down the focus of an analysis. All transcriptions and written documents were reviewed carefully and repeatedly to find rich evidence through inductive and content analysis. The findings revealed that ESE provided a conceptual focus and theme for organizing his school curriculum. The curriculum offered opportunities for students to learn relevant local topics and to connect the classroom learning to the real world. The curriculum also played an important role in developing students' value and appreciation of Earth systems and concern for the local environment. His instructional strategies were very compatible with recommendations from a constructivist theory. His major teaching methodology and strategies were hands-on learning, authentic activities-based learning, cooperative learning, project-based learning (e.g., mini-projects), and science field trips. With respect to his views about benefits and difficulties associated with ESE, the most important benefit was that the curriculum provided authentic-based, hands-on activities and made connections between students and everyday life experiences. In addition, he believed that it was not difficult to teach using ESE. However, the lack of time devoted to field trips and a lack of suitable resource materials were obstacles to the implementation of the curriculum. Implications for science education and future research are suggested.

A Deformation Model of a Bag-Finger Skirt and the Motion Response of an ACV in Waves (Bag-Finger형 스커트의 변형모델과 규칙파중 공기부양선의 운동해석)

  • G.J. Lee;K.P. Rhee
    • Journal of the Society of Naval Architects of Korea
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    • v.29 no.2
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    • pp.48-59
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    • 1992
  • In this paper, the effects of a skirt deformation on the responses of an Air Cushion Vehicle in waves are investigated. The air in the bag and in the plenum chamber is assumed to be compressible and to have a uniform instantaneous pressure distribution in each volume. The free surface deformation is determined in the framework of linear potential theory by replacing the cushion pressure with the pressure patch moving uniformly with an oscillating strength. And the bag-finger skirt is assumed to be deformed due to the pressure disturbance while its surface area remained constant. The restoring force and moment due to the deformation of bag-finger skirt from the equilibrium shape is included in the equations of hearse and pitch motions. The numerical results of motion responses due to various ratios of the bag and cushion pressure or bag-to-finger depth ratios are shown.

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Development of Eddy Current Test Probe for Profilometry Inspection of Tube (원형튜브 단면형상검사용 와전류탐촉자 개발)

  • Lee, H.J.;Nam, M.W.;Lee, C.H.
    • Journal of the Korean Society for Nondestructive Testing
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    • v.17 no.4
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    • pp.262-269
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    • 1997
  • An eddy current probe ($8{\times}1$ multiple-element, surface scan) was successfully designed and fabricated at the KEPRI using the impedance equivalent circuit theory. The probe is intended for the detection of circumferential deformations (cross-section view) of the heat exchanger tubing that can occur due to corrosion, erosion, and denting. Optimum design parameters providing the highest sensitivity and signal-to-noise ratio, such as the coil dimensions, electrical characteristics, and test frequencies, were determined based on initial laboratory experiments conducted on the test specimen (SS304 tubing: OD : 9.68mm, wall-thickness : 0.47mm) containing artificial flaws (e.g., dents and corroded surface on tube OD) using the available Zetec-made probe. Using this parameters, a new probe was made and tested on an unknown specimen. The result indicated that the new probe is capable of detecting the circumferential deformation with the error of ${\pm}0.2%$ (0.022mm) of the tube O.D.

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Molecular dynamics study of redeposition effect by Ar ion bombardments on Au, Pd(001) (Ar이온 충돌에 의한 Au, Pd(001) 표면에서 재증착 효과의 분자동역학 연구)

  • Kim, S.P.;Kim, S.J.;Kim, D.Y.;Chung, Y.C.;Lee, K.R.
    • Journal of the Korean Vacuum Society
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    • v.17 no.2
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    • pp.81-89
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    • 2008
  • Atomic behavior during ion beam sputtering was investigated by using classical molecular dynamics simulation. When Ar ion bombards on Au and Pd(001) surface with various incidence energies and angles, some atoms which gained substantial energy by impacting Ar ion were sputtered out and, simultaneously, others were landed on the surface as if surface atoms were redeposited. It was observed that the redeposited atoms are five times for Au and three times for Pd as many as sputtered atoms irrespective of both incidence energy and angle. From sequential ion bombarding calculations, contrary to the conventional concepts which have described the mechanism of surface pattern formation based only on the erosion theory, the redeposition atoms were turned out to play a significant role in forming the surface patterns.

The Principles of Total Quality Management(TQM) and Its Implementation. (총체적 질관리(Total Quality Management)의 이론적 배경과 그 적용실태)

  • Kang, So-Young
    • Journal of Korean Academy of Nursing Administration
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    • v.1 no.2
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    • pp.388-407
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    • 1995
  • This study is (a) to describe the history of Total Quality Management (TQM) generated in the industry, health care service, and nursing society ; (b) to define the concept, total quality management including the definition of quality ; (C) to explain the each principle of TQM theory developed by main theorists, E. Deming, J. Juran, and B. Crosby ; (d) to give the examples related to TQM implementation at the health care organization ; and (e) to mention the extent to which the health care organizations are able to evaluate their cultural organization toward TQM and have had the way to measure the effect of TQM implementation. TQM referred to Continuous Quality Improvement(CQI), Quality Improvement(QI), and Total Quality Improvement(TQI), was not recognized by experts in the United States industry, but by economists in Japan until the end of the 1970's. However, the United States' government led to introduce the principles of TQM to general industry as well as health care service area so that TQM became a main philosophy to manage the organizations in health care service. TQM is a structured, systematic process for creating organization-wide participation in planning and implementing continuous improvement in quality. E. Deming established the "Chain reaction in Quality" and the fourteen point of TQM. The Chain reaction in quality is to describe the relationship among the reduction of waste, rework, and delay, quality improvement, customer satisfaction, and productivity. There are fourteen points to explain the principles of TQM by E. Deming. Juran defined the "Quality Trilogy" to improve the level of quality in any organization. Quality Trilogy has three steps such as quality planning, quality control, and quality improvement for implementing the TQM projects. Crosby describes his TQM theory by establishing "Four Absolutes" and "Fourteen steps in TQM" implementation. Until now, most healthcare organizations have made efforts to organize the TQM task team and to implement TQM principles with various issues. There are three priorities to select the TQM issues : High-volume, High-risk, and Problem-prone. However, there is no absolute, credible measurement yet to evaluate the effects of TQM implementation in health care organization regardless of the classification of health care organizations, geographical background, and social influence. Thus, developing the evaluation way in terms of TQM is the foremost task in health service area. The most important thing for TQM implementation in the organization is to settle up the concept, cultural transformation from traditional management toward quality.

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Analysis of the Physiological Signal Measured by Oriental Medicine Instruments in the View of the Rule of Promoting and Counteracting Relation of the Five Evolutive Phases (한방기기(韓方機器)로 측정(測定)한 생리신호(生理信號)의 오행(五行) 생극제화규율적(生剋制化規律的) 해석(解析))

  • Jang, K.S.;Choi, J.W.;Jean, C.S.;Na, C.S.;So, C.H.
    • Korean Journal of Oriental Medicine
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    • v.2 no.1
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    • pp.84-103
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    • 1996
  • The physiological signals measured by Oriental Medicine instruments have been analyzed quantitatively in the view of the rule of promoting and counteracting relation of five evolutive phases theory. We tried to reduce the physiological signals measured by EAV(Elec-tro-Acupuncture according to Voll) and IR thermography to the representation of five evelutive phases. The EAV index and local skin temperature on acupuncture points of each phases measured and normalized so that the total value of five phases became unity. We assumed that the normalized EAV index and local skin temperature mean the deficiency or excess of Qi for each phases. The state of Qi distribution for each phases were approximately agree with the diagnostic pattern of O. M. doctor. Taking account of the Qi distribution state of·or the five evolutive phases, we performed a proper needle insertion on acupuncture points to induce the distinct change of Qi for each phases. We compared the measured results with the predictions of Qi variation by the rule of pro- moting and counteracting relation over the five evolutive phases. For all cases, the variation of Qi in the own phase on which a needle insertion was performed were exactly same to the theoretical prediction and partial agreement was shown for the other four phases. The same analysis was carried to the results of skin temperature measurements at accupoints. We found that the local skin temperature at accupoints of each phases shelved a finite change by the needle insertion and the behavior- of its change were strongly correlated to the rule of promoting and counteracting relation of five evolutive phases.

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A Study on the Effect of Self-Management and Relaxation Training through Biofeedback on Influencing the Stress Response and Immune Functions (바이오휘드백을 통한 자기조절 훈련이 스트레스반응과 면역기능에 미치는 효과에 관한 연구)

  • 이소우;김금순;박성회
    • Journal of Korean Academy of Nursing
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    • v.29 no.4
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    • pp.855-869
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    • 1999
  • The purpose of this study was to test the effectiveness of self-management relaxation training through biofeedback and progressive muscle relaxation methods. The effectiveness of the experimental methods was tested by measuring the degree of symptoms of stress (SOS), the McNair's profile of Mood States (POMS), the levels of ephinephrine, norepinephrine, pulse rate, blood pressure and natural killer cells. The subjects of this study were sixty six nursing students divided into four groups : two groups were the biofeedback and progressive muscle relaxation groups, the other two groups served as control groups. One was a group of sophomores with no experience at all, the other a junior group without self -management or relaxation training. This study was conducted for eight weeks of clinical practice from April, 26th 1998 to June, 20th 1998. Biofeedback training was done with software developed by J&J company (1-410 form for abdominal respiration training). Progressive muscle relaxation training was done with u audiotape recorded according to Jacobson's Theory. The data were analyzed with frequencies, means, and analysis of covariance using the SPSS program and the significance level of statistics was 5%. The results of the study are : 1) The importance of clinical practice stress reduction is shown in that the level of symptoms of stress in the experimental groups in clinical practice was higher than in the group receiving only a lecture. 2) The relaxation training methods of biofeedback and progressive muscle relaxation were effective in reducing the symptoms of stress under the clinical practice stress conditions. 3) The effectiveness of the biofeedback training relaxation method to reduce symptoms of stress was higher than that of progressive muscle relaxation. 4) The relaxation training methods of biofeedback and progressive muscle relaxation were effective in reducing stressful mood states. 5) The relaxation training methods of biofeedback and progressive muscle relaxation were not effective in reducing epinephrine and norepinephrine levels. 6) The relaxation training methods of biofeedback and progressive muscle relaxation were effective in increaing the number of natural killer cells. 7) The relaxation training methods of biofeedback and progressive muscle relaxation were effective in decreasing high systolic and diastolic values of blood pressure and high pulse rates. In summary, the relaxation methods of biofeedback and progressive muscle relaxation in reducing clinical practice stress were effective in lowering the level of symptoms of stress and the profile of stressful mood states. They were also effective in lowering high blood pressure and pulse rates. The relaxation methods were effective in increasing the number of natural killer cells as part of the immune function. However, relaxation methods were not effective in reducing the catecholamine level. The biofeedback training method for reduction of symptoms of stress was more effective than the progressive muscle relaxation method.

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A Review of Four Translated Statistics Books (통계학책 번역서 네 권에 대한 비평)

  • 조재근
    • The Korean Journal of Applied Statistics
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    • v.17 no.3
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    • pp.573-594
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    • 2004
  • Four statistics books, one translated by statisticians and three by non-statisticians, are reviewed. They are reviewed in terms of indices and bibliographies, statistical theory and terms, and the history of statistics. In addition, book review articles appeared in daily newspapers are considered. Unfortunately, we can find many(some of them trivial, and some others serious) problems in the translations. Many problems could have been got around if the books had been translated by statisticians. So, conclusion suggested in this article is very simple: Translation of statistics books, especially books for the laymen, is a job that Korean statisticians should not shift to others. Titles of the books reviewed in this article are as follows. 1. Rao, C. Radhakrishna(1997). Statistics and Truth : Putting Chance to Work, Second edition, World Scientific. 2. Best, Joel (2001). Damnel lies and Statistics : Understanding Numbers from the Media, Politicians, and Activists, University of California Press. 3. Bennett, Deborah J. (1998). Randomness, Harvard University Press; 4. Salsburg, David (2001). The Lady Tasting Tea : How Statistics Revolutionized Science in the Twentieth Century, W. H. Freeman.

Effect of Different Front Metal Design on Efficiency Affected by Series Resistance and Short Circuit Current Density in Crystalline Silicon Solar Cell (결정질 실리콘 태양전지의 전면 전극의 패턴에 따른 전류 밀도 및 특성 저항 변화에 대한 영향과 효율 변화)

  • Jeong, Sujeong;Shin, Seunghyun;Choi, Dongjin;Bae, Soohyun;Kang, Yoonmook;Lee, Hae-seok;Kim, Donghwan
    • Korean Journal of Materials Research
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    • v.27 no.10
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    • pp.518-523
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    • 2017
  • In commercial solar cells, the pattern of the front electrode is critical to effectively assemble the photo generated current. The power loss in solar cells caused by the front electrode was categorized as four types. First, losses due to the metallic resistance of the electrode. Second, losses due to the contact resistance of the electrode and emitter. Third, losses due to the emitter resistance when current flows through the emitter. Fourth, losses due to the shading effect of the front metal electrode, which has a high reflectance. In this paper, optimizing the number of finger on a $4{\times}4$ solar cell is demonstrated with known theory. We compared the short circuit current density and fill factor to evaluate the power loss from the front metal contact calculation result. By experiment, the short circuit current density($J_{sc}$), taken in each pattern as 37.61, 37.53, and $37.38mA/cm^2$ decreased as the number of fingers increased. The fill factor(FF), measured in each pattern as 0.7745, 0.7782 and 0.7843 increased as number of fingers increased. The results suggested that the efficiency(Eff) was measured in each pattern as 17.51, 17.81, and 17.84 %. Throughout this study, the short-circuit current densities($J_{sc}$) and fill factor(FF) varied according to the number of fingers in the front metal pattern. The effects on the efficiency of the two factors were also investigated.

Wall Shear Stress Distribution in the Abdominal Aortic Bifurcation : Influence of wall Motion, Impedance Phase Angle, and non-Newtonian fluid (복부대동맥 분기관에서의 벽면전단응력 분포 벽면운동과 임피던스 페이즈 앵글과 비뉴턴유체의 영향)

  • Choi J.H.;Kim C.J.;Lee C.S.
    • Journal of Biomedical Engineering Research
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    • v.21 no.3 s.61
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    • pp.261-271
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    • 2000
  • The present study investigated flow dynamics of a two-dimensional abdominal aortic bifurcation model under sinusoidal flow conditions considering wall motion. impedance phase angle(time delay between pressure and flow waveforms), and non-Newtonian fluid using computational fluid dynamics. The wall shear stress showed large variations in the bifurcated region and the wall motion reduced amplitude of wall shear stress significantly. As the impedance phase angle was changed to more negative values, the mean wall shear stress (time-averaged) decreased while the amplitude (oscillatory) of wall shear stress increased. At the curvature site on the outer wall where the mean wall shear stress approached zero. influence of the phase angle was relatively large. The mean wall shear stress decreased by $50\%$ in the $-90^{\circ}$ phase angle (flow wave advanced pressure wave by a quarter period) compared to the $0^{\circ}$ phase angle while the amplitude of wall shear stress increased by $15\%$. Therefore, hypertensive patients who tend to have large negative phase angles become more vulnerable to atherosclerosis according to the low and oscillatory shear stress theory because of the reduced mean and the increased oscillatory wall shear stresses. Non-Newtonian characteristics of fluid substantially increased the mean wall shear stress resulting in a less vulnerable state to atherosclerosis.

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