• 제목/요약/키워드: Critical Analysis

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지질별 불포화토 사면의 붕괴 임계심도 분석 (Analysis on Failure Critical Depth of Unsaturated Landslide Zone According to the Geological Condition)

  • 남경훈;김민규;정교철
    • 지질공학
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    • 제25권2호
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    • pp.299-304
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    • 2015
  • 강우침투로 인한 불포화토 사면의 안정해석이 산사태 분석 및 사면 안정성을 평가하는데 주요 문제로 부각되고 있다. 본 연구에서는 강우강도를 고려하여 국내 산사태 발생부의 모암별 풍화토층의 붕괴 임계심도를 파악하고자 하였다. 분석 결과 강우강도 및 사면경사 증가에 따라 편마암 풍화토는 임계심도가 3.00 m에서 3.77 m로 증가하였고, 화강암 풍화토는 임계심도가 1.75 m에서 2.40 m로 증가하였으며, 이암 풍화토는 3.00 m에서 4.15 m로 증가하였다. 점착력이 낮고 내부 마찰각이 높은 화강암 풍화토에서 붕괴 임계심도가 낮은 경향을 보였으며 강우강도에 의한 안전율 감소보다 사면경사 증가에 따른 안전율 감소가 다소 크게 발생하는 것으로 나타났다.

곡선교의 내진 해석 시 곡률에 따른 하중 조합 방법의 비교에 관한 연구 (A Study on Comparison of Combination Rules for the Seismic Analysis on Curved Bridges with the Different Radiuses of Curvature)

  • 류동현;신명규;박진완;김문겸
    • 한국전산구조공학회:학술대회논문집
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    • 한국전산구조공학회 2008년도 정기 학술대회
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    • pp.567-572
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    • 2008
  • This paper's purpose is to improve determining of the critical response of curved bridge to multi-component seismic motion. There are several methods to combine responses by multi-component excitation response, 30%, 40% rules and square-root-of-sum (SRSS). These combination rules determine same value of critical response in straight bridges. However, each method has critical response value of different magnitude in curved bridges. Thus a study about critical response of curved bridges is required. This paper presents comparison critical responses value as each combination rule, 30%, 40% rules and SRSS on curved bridges with the different radiuses of curvature. This study was carried out by response spectrum analysis of OO IC steel box girder bridge using SAP2000. It is concluded as follows: 1) In curved bridges, 30% and 40% rules tend to underestimate the critical response relatively to SRSS. 2) When bridges have smaller radiuses than 100m, difference between SRSS and 30% or 40% rules let run errors up as radiuses of curvature decreased.

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Critical setback distance for a footing resting on slopes under seismic loading

  • Shukla, Rajesh Prasad;Jakka, Ravi S.
    • Geomechanics and Engineering
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    • 제15권6호
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    • pp.1193-1205
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    • 2018
  • A footing located on slopes possess relatively lower bearing capacity as compared to the footing located on the level ground. The bearing capacity further reduces under seismic loading. The adverse effect of slope inclination and seismic loading on bearing capacity can be minimized by proving sufficient setback distance. Though few earlier studies considered setback distance in their analysis, the range of considered setback distance was very narrow. No study has explored the critical setback distance. An attempt has been made in the present study to comprehensively investigate the effect of setback distance on footing under seismic loading conditions. The pseudo-static method has been incorporated to study the influence of seismic loading. The rate of decrease in seismic bearing capacity with slope inclination become more evident with the increase in embedment depth of footing and angle of shearing resistance of soil. The increase in bearing capacity with setback distance relative to level ground reduces with slope inclination, soil density, embedment depth of footing and seismic acceleration. The critical value of setback distance is found to increase with slope inclination, embedment depth of footing and density of soil. The critical setback distance in seismic case is found to be more than those observed in the static case. The failure mechanisms of footing under seismic loading is presented in detail. The statistical analysis was also performed to develop three equations to predict the critical setback distance, seismic bearing capacity factor ($N_{{\gamma}qs}$) and change in seismic bearing capacity (BCR) with slope geometry, footing depth and seismic loading.

Concurrent Modeling of Magnetic Field Parameters, Crystalline Structures, and Ferromagnetic Dynamic Critical Behavior Relationships: Mean-Field and Artificial Neural Network Projections

  • Laosiritaworn, Yongyut;Laosiritaworn, Wimalin
    • Journal of Magnetics
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    • 제19권4호
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    • pp.315-322
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    • 2014
  • In this work, Artificial Neural Network (ANN) was used to model the dynamic behavior of ferromagnetic hysteresis derived from performing the mean-field analysis on the Ising model. The effect of field parameters and system structure (via coordination number) on dynamic critical points was elucidated. The Ising magnetization equation was drawn from mean-field picture where the steady hysteresis loops were extracted, and series of the dynamic critical points for constructing dynamic phase-diagram were depicted. From the dynamic critical points, the field parameters and the coordination number were treated as inputs whereas the dynamic critical temperature was considered as the output of the ANN. The input-output datasets were divided into training, validating and testing datasets. The number of neurons in hidden layer was varied in structuring ANN network with highest accuracy. The network was then used to predict dynamic critical points of the untrained input. The predicted and the targeted outputs were found to match well over an extensive range even for systems with different structures and field parameters. This therefore confirms the ANN capabilities and indicates the ANN ability in modeling the ferromagnetic dynamic hysteresis behavior for establishing the dynamic-phase-diagram.

중소기업 정보화의 성공요인에 관한 전자업종과 섬유업종의 비교 연구 (Comparative Study on the Critical Success Factors of Information Systems of Small-and-Medium-sized Companies : Electronic Industry versus Textile Industry)

  • 김병곤
    • 한국정보시스템학회지:정보시스템연구
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    • 제11권1호
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    • pp.151-173
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    • 2002
  • The purpose of the current study is to identify the critical success factors of information systems in small-and-medium-sized firms in general, and also to investigate any differences of those critical success factors between two different industries: the electronic and textile industries. To accomplish this purpose, we collected and analyzed 115 and 108 questionnaires from the electronic and textile industries respectively. From the results of statistical analysis, critical success factors of small-and-medium-sized companies in general were obtained, and critical success factors from two industries were compared and the differences were able to be identified. The results of the analysis of the questionnaires are as follows: 1) The organizational characteristics of the electronic industry showed some differences from those of the textile industry; 2) Small-and-medium-sized companies in the electronic industry appeared to have some differences from companies in the textile industry in terms of critical success factors of information systems. Such factors as education and training, quality level of software, capability of users, business processes, standardization of data management, level of organization, user involvement, support of top management were significantly different between two industries.

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중환자실 환자가 경험한 인간중심 간호에 관한 질적 내용분석 (A Qualitative Content Analysis of the Person-Centered Care Experienced by Critical Care Patients)

  • 홍희진;강지연
    • 중환자간호학회지
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    • 제11권2호
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    • pp.21-33
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    • 2018
  • Purpose : To explore the person-centered care (PCC) experienced by critical patients. Method : This qualitative study deductively examined the attributes of the PCC model proposed by Jakimowicz and Perry. The participants were 16 patients who were recently discharged from intensive care units at a university hospital. Data were collected through in-depth interviews and were analyzed using the deductive method of content analysis. Results : A total of 4 categories, 16 subcategories, and 33 codes were generated from 171 meaningful statements. The final 4 categories were "compassionate presence," "professional interaction," "outstanding competency," and "patient identity." These were consistent with the main attributes of Jakimowicz and Perry's model. However, most of the codes belonged to the "compassionate presence" and "patient identity" categories. Among the attributes of the model, "continuity of nursing," "therapeutic relationship," "expert knowledge," "clinical knowledge," "evidence-based intervention," and "patient's rights" were not derived as codes. Conclusion : These findings deepen the understanding of the PCC model from the patient's point of view. The main attributes of PCC identified in the current study can be applied to the development of practical guidelines for intensive care nursing. In addition, we recommend the development of a PCC measurement tool for critical care patients.

Analytical Tools for Ideological Texts in Critical Reading Instruction

  • Lee, Jong-Hee
    • 영어어문교육
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    • 제10권3호
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    • pp.89-112
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    • 2004
  • This article examines the ways in which language can be exploited in the manipulation of the reader's interpretation of a text to make him/her take certain lines of thought according to the writer's persuasive intents. Such functions of language provide valid foundations to support the teaching of critical reading skills and to explore an adequate approach to discourse analysis. A pilot study was conducted to find out the extent to which the reader can be coaxed into thinking in some fashions guided by specific linguistic devices employed for ideological texts. Forty-seven subjects divided into two groups (humanities majors and natural science majors at undergraduate level) joined the two-fold questionnaire surveys intended to look at their critical reading abilities. The empirical results indicate that college students whose majors are humanities were more inclined to take a holistic approach in processing commercial advertisement texts and their abilities for critical interpretation appeared to be lower than those of the subjects whose majors are natural sciences, who showed a relatively high tendency to take an analytical approach in decoding the textual facts. As a consequence, pedagogic implications for increasing critical reading abilities have resulted in a set of analytical procedures concerning ideological texts which is linked with instructional guidelines to emphasize the importance of the reader's logical and analytical reasoning power, entirely accepted as a general prerequisite for cracking the covert language gambits.

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100,000 rpm 운전용 원심분리기 로터-베어링 시스템의 회전체동역학 해석 (Rotordynamics of a Centrifuge Rotor-Bearing System for 100,000 rpm Operation)

  • 이안성;김영철;박종권
    • 소음진동
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    • 제8권3호
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    • pp.450-456
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    • 1998
  • A rotordynamic analysis is performed with a centrifuge rotor-bearing system for the raing speed of 100,000 rpm. The system is composed of a centrifuge rotor(or simply the rotor), flexible shaft, motor rotor and shaft, and two support rolling element bearings of the motor shaft. Design goals are to achieve wide separation margins of critical speeds and favorable unbalance responses of the rotor at the associated critical speeds. The latter requirements are especially important as the system crosses multiple numbers of critical speeds and as the system may not have enough separaton margins around the rating speed. As the system adopts an extra-flexible shaft, it is shown that the rotor has satisfactory small unbalance responses over higher criticals while having an unsatisfactory large one at the first critical. To supress this a bumper ring or guide bearing needs to be installed at a suitable location of the flexible shaft. It is also shown that even with the flexible shaft the dynamics of the motor must be incoporated into the full system model to accurately identify the fourth critical speed, which is close to the rating speed, and higher ones. The analysis is based on the finite element method.

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중환자전문간호사들의 실무경험: 포커스 그룹 연구 (Korean Critical Care Advanced Practice Nurses' Work Experience: A Focus Group Study)

  • 김금순;김복자;이영희;강지연
    • 중환자간호학회지
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    • 제4권2호
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    • pp.1-14
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    • 2011
  • Purpose: This study was aimed to understand and describe the Korean critical care advanced practice nurses' work experience. Methods: Data was collected through 2 focus group interviews that were held in two different university hospitals in Seoul, Korea. All interviews were recorded and transcribed, and data were analysed using modified qualitative content analysis. Results: Ten themes were drawn from data analysis. They are "Various and complex tasks", "Excellency of advanced nursing practice", "Pressure and responsibility accompanied with pride", "Role identity confusion", "Role conflict", "Leaping and evolving role", "Gap between role and outcome evaluation", "Underestimated outcomes", "Where are my outcomes?" "Searching for outcomes: publicize the role". Conclusion: The results of this study help to understand the role of Korean critical care advanced practice nurses and to guide to outcome evaluation of their role effectiveness. Developing qualitative outcome indicators, cost-effectiveness ananlysis of Korean critical care advanced practice nurses' role, and accumulation of evidences through researches on outcome evaluation will be needed to successfully settle down advanced practice nursing in Korea.

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간호사의 의사소통 유형, 비판적 사고 성향, 직무만족도 및 직무 스트레스에 관한 연구 (A Study of Communication Style, Critical Thinking Disposition, Job Satisfaction and Job Stress in Hospital Nurses)

  • 박효미;이혜순
    • Perspectives in Nursing Science
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    • 제8권2호
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    • pp.105-112
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    • 2011
  • Purpose: The purpose of this study was to identify the predictors of job stress in hospital nurses. The predictors of job stress were the subject's general characteristics, communication style, critical thinking disposition and job satisfaction. Methods: 294 nurses who had worked in a hospital participated in this study. The data were analysed with descriptive analysis methods including a t-test, ANOVA, Scheffe test, Pearson correlation coefficient and multiple regression analysis. Results: The job stress score for nurses was 111.6. There was a statistically significant difference between job stress and marriage status (p<.001), education (p<.001), clinical career (p<.001), position (p<.001), communication style (p<.001), critical thinking disposition (p<.001), and job satisfaction (p<.001). Critical thinking disposition, job satisfaction and clinical career together accounted for 36.88% of the total variation in job stress. Conclusion: Based on the findings of this study, the development of a nursing intervention program that can lead to an improvement in critical thinking disposition is suggested.

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