• Title/Summary/Keyword: Transition study

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Dynamic Behavior on Transition Zone of the Railway Bridge-earthwork by Shape of Transition Zone (구조물 접속부 형상에 따른 철도 교량-토공 접속부의 동적거동)

  • Jung, Kwangsu;Ahn, Kwangkuk;Kang, Hongsig
    • Journal of the Korean GEO-environmental Society
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    • v.22 no.4
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    • pp.5-13
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    • 2021
  • The transition is the zone where support stiffness suddenly increases in the railway industry. If the support stiffness increases, differential settlement will occur at the transition due to difference of stiffness, and the differential settlement causes problems for the train running safety and the roadbed that supports the track. In particular, a study on differential settlement at bridge-earthwork transition was only conducted to considering railway load in most cases. However, these studies have not taken account of earthquake despite earthquake has been occurred frequently in the recent, and it is necessary to consider earthquake. Therefore, in this study numerical analysis has been performed by changing the inclination of approach block, which determines the shape of the transition, and earthwork in order to verify the effect of the shape of the transition on the dynamic behavior at the bridge-earthwork transition. The result shows that the dynamic behavior at the bridge-earthwork transition was affected by the shape of transition.

A study the ink transition of polycarbonate by using of screen printing technioque (Screen 인쇄기법을 이용한 Polycarbonate의 Ink 전이성에 관한 연구)

  • 신종순;강영립;최명철
    • Journal of the Korean Graphic Arts Communication Society
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    • v.19 no.2
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    • pp.49-57
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    • 2001
  • This thesis attempts to study ink transition for on the polycarbonate multicalculator plate for automobile. For this study, the change of weight by screen printed ink transition on polycarbonate material by ink viscosity(be diluted ; 0%, 5%, 10%, 20%) was observed. The weight by screen printed ink is depended on amount of added solvent. We have studied change of the weight by the transition of the ink that was screen-printed on polycarbonate which is to be printed according to the viscosity of the ink (diluent: undiluted solution 5%, 10%, 15%, 20%). This shows that ink transition become activated since the amount of ink(or/and the viscosity of ink) is increased.

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Study on the transient flow induced by the windbreak transition regions in a railway subject to crosswinds

  • Zheng-Wei, Chen;Syeda Anam, Hashmi;Tang-Hong, Liu;Wen-Hui, Li;Zhuang, Sun;Dong-Run, Liu;Hassan, Hemida;Hong-Kang, Liu
    • Wind and Structures
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    • v.35 no.5
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    • pp.309-322
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    • 2022
  • Due to the complex terrain around high-speed railways, the windbreaks were established along different landforms, resulting in irregular windbreak transition regions between different subgrade infrastructures (flat ground, cutting, embankment, etc). In this paper, the effect of a windbreak transition on the wind flow around railways subjected to crosswinds was studied. Wind tunnel testing was conducted to study the wind speed change around a windbreak transition on flat ground with a uniform wind speed inflow, and the collected data were used to validate a numerical simulation based on a detached eddy simulation method. The validated numerical method was then used to investigate the effect of the windbreak transition from the flat ground to cutting (the "cutting" is a railway subgrade type formed by digging down from the original ground) for three different wind incidence angles of 90°, 75°, and 105°. The deterioration mechanism of the flow fields and the reasons behind the occurrence of the peak wind velocities were explained in detail. The results showed that for the windbreak transition on flat ground, the impact was small. For the transition from the flat ground to the cutting, the influence was relatively large. The significant increase in the wind speeds was due to the right-angle structure of the windbreak transition, which resulted in sudden changes of the wind velocity as well as the direction. In addition, the height mismatch in the transition region worsened the protective effect of a typical windbreak.

Transition of Simulation-Based Learning in Nursing Schools: A Concept Analysis (간호대학 시뮬레이션 교육의 이행(transition)에 대한 개념 분석)

  • Ha, Yi Kyung;Bang, Hwal Lan;Lee, Yeon Hee
    • Journal of Korean Critical Care Nursing
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    • v.12 no.2
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    • pp.50-60
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    • 2019
  • Purpose : The purpose of this study was to identify the attributes, antecedents, and consequences of the transition of simulation-based learning (SBL) in nursing schools. Methods : The study was conducted in accordance with Walker and Avant's conceptual analysis process. We searched MEDLINE, CINAHL, EMBASE, Google Scholar, and RISS (Korean Education and Research Information Service) databases, resulting in nine studies for an in-depth review. Results : The attributes of transition of SBL include (1) preparing for a professional role, (2) practicing in a real clinical setting, and (3) progressing toward expected competency. Antecedents of the concept include novice status, changing roles, clinical experience in controlled settings, and expected competency in the clinical setting. Conclusion : The transition of SBL includes the important feature of progression toward expected competency. Further research is needed to identify graduate nurses' experiences during this transition to establish a strategy for improving it and developing a measurement tool that reflects attributes of the concept.

GI transition and disintegration test of enteric coated capsules using radiopaque material in rabbits (토끼에서 조영제를 이용한 장용성 capsule의 GI transition과 disintegration에 관한 검사)

  • Kim, Myung-cheol;Kim, Nam-joong
    • Korean Journal of Veterinary Research
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    • v.35 no.2
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    • pp.391-398
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    • 1995
  • This study was carried to investigate the usefulness of the radiopaque material as the GI transition and disintegration test of enteric coated capsules radiologically. The obtained results were as follows; 1. The GI transition times that the enteric coated capsules pass through the pylorus were that the time of the first capsule was 210 minutes and the time of the last capsules was more than 300 minutes. Therefore, the GI transition times largely differ from each animal and each enteric coated capsule. 2. The disintegration times of enteric coated capsules were similar in vitro test and in vivo test. 3. The GI transition and disintegration test of enteric coated capsules using barium sulfate, radiopaque material for the gastrointestinal track, was useful to investigate the times that the capsules passed through the pylorus and disintegrated in intestinal track.

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Effects of Hydraulic Variables on the Formation of Freshwater-Saltwater Transition Zones in Aquifers

  • Park, Nam-sik
    • Korean Journal of Hydrosciences
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    • v.7
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    • pp.1-8
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    • 1996
  • The location and the shape of a freshwater transition zone in a coastal aquifer are affected by many hydraulic variables. To data most works to determine the effects of these variables are limited to qualitative comparison of transiton zones. In this work characteristics of transition zones are analyzed quantitatively. The investigation is limited to a steady-state transition zones. Three dimensionless variables are defined to represent characteristics of steady-state transition zones. They are maximum introsion length, thickness, and degree of stratification. Effects of principal hydraulic variables (velocity and dispersivity) on these characteristics are studied using a numerical model. Dimensional analysis is used to systematically analyze entire model results. Effects of velocity and dispersivity are seem clearly. From this study, increase in velocity is found to cause shrinkage of transition zones. This observation contradicts claims by some that, because dispersion is proportional to velocity, increase in velocity would cause expansion of transition zones.

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A Theoretical Study on the Low Transition Temperature of VO2 Metamaterials in the THz Regime

  • Kyoung, Jisoo
    • Current Optics and Photonics
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    • v.6 no.6
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    • pp.583-589
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    • 2022
  • Vanadium dioxide (VO2) is a well-known material that undergoes insulator-to-metal phase transition near room temperature. Since the conductivity of VO2 changes several orders of magnitude in the terahertz (THz) spectral range during the phase transition, VO2-based active metamaterials have been extensively studied. Experimentally, it is reported that the metal nanostructures on the VO2 thin film lowers the critical temperature significantly compared to the bare film. Here, we theoretically studied such early transition phenomena by developing an analytical model. Unlike experimental work that only measures transmission, we calculate the reflection and absorption and demonstrate that the role of absorption is quite different for bare and patterned samples; the absorption gradually increases for bare film during the phase transition, while an absorption peak is observed at the critical temperature for the metamaterials. In addition, we also discuss the gap width and VO2 thickness effects on the transition temperatures.

Coal-fired power plants closure and just transition of port labour employment (화력발전소 폐쇄와 항만인력 고용의 공정한 전환)

  • Su-Han Woo;Du-Ri Kim
    • Korea Trade Review
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    • v.45 no.5
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    • pp.55-74
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    • 2020
  • This study examines the policy direction and specific countermeasures for addressing possible port labour issues from the perspective of Just Transition which may be raised by closing coal fired power plants in Korea. Current energy transition policy and port labour policy in Korea are reviewed and case studies in the countries which has experienced closure of coal fired power plants are undertaken. Although it varies from country to country, a similar approach was found that the employment problem of coal fired power plant closures and measures based on Just Transition regime to mitigate the negative impacts that occur in the region are the key to successful transition. It is suggested that countermeasures for port labour should be institutionalized for providing stakeholders with legal stability covering labours not only directly employed by the plants but also employed in entities in the whole supply chains.

The Influence of Infant's Temperament on Childcare Adaptation: Moderated Effect of Teacher-Infant Relationships (영아의 기질과 어린이집 초기적응 간 관계에서 교사 - 영아관계의 조절효과: 수직적 전이집단과 수평적 전이집단을 중심으로)

  • Lee, Sang soon;Lee, Wan jeong
    • Korean Journal of Childcare and Education
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    • v.15 no.2
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    • pp.21-36
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    • 2019
  • Objective: The purpose of this study was to analyze the effects of infant temperament on adaptation at childcare centers and the moderated effects of teacher-infant relationships between a vertical transition group and horizontal transition group. Methods: The subjects of the study were 284 infants, aged 1-years-old and 2-years-old, who were hospitalized in childcare centers. To investigate the correlation between variables, Pearson correlation analysis was used. Regression analysis was performed to check the effects of temperament and teacher-infant relationship on childcare adaptation. Results: Infant temperament influenced childcare adaptation in both vertical and horizontal transition groups. The quality of teacher-infant relationships was found to moderate the relationship between infant temperament and childcare adaptation in both groups. Conclusion/Implications: The results of this study, which showed different moderating effects of the teacher-infant relationship in the vertical transfer group and the horizontal transfer group, suggest the need for more diverse studies on the various transition experiences regarding childcare transition.

Beam Transition Elements for Finite Element Analysis of Transition Regions of Coupled Wall Structures (병렬전단벽 구조물의 변화부분의 유한요소해석을 위한 보-변환요소의 개발)

  • 김호수
    • Computational Structural Engineering
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    • v.8 no.2
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    • pp.85-93
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    • 1995
  • This study presents the formulation of beam transition elements and transition zone elements for the effective finite element analysis of the transition regions of coupled wall structures. Beam transition element can be described as the quasi beam element which is replaced by an equivalent plane stress element, keeping equally, the basic behavior of beam element, based on the kinematic and force constraints between beam and wall element. These beam transition elements solve the incompatibility related to different degrees of freedom between beam and wall element in transition regions. Also, the stiffness matrices of transition zone elements which are directly connected with beam transition elements in transition regions can be derived from the equivalent constraint conditions. These elements provide the reasonable mesh grading schemes for transition regions and can be usefully applied to the transition regions of all structures that the interactions of wall and beam element are considered.

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