• Title/Summary/Keyword: Size Effects

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The Effects of Age, Gender and Head Size on the Cortical Thickness of Brain (연령, 성별, 머리 크기가 대뇌 피질 두께에 미치는 효과)

  • Park, Yunyoung;Kim, Siekyeong
    • Korean Journal of Biological Psychiatry
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    • v.22 no.3
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    • pp.118-127
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    • 2015
  • Objectives Standardization of head size is essential for the volume study. Cortical thickness analyses are increasingly being used in many fields of neuroscience. However, it is not established whether head size correction should be done for thickness study. Methods Using the Open Access Series of Imaging Studies data, we determined cortical thickness of 316 cognitively normal participants aged 18-94 with FreeSurfer. The association between head size and cortical thickness of whole cortical mantle and in each lobe among age tertile groups was assessed. Estimated total intracranial volume (eTIV) was calculated for determining head size. Results Across all participants, cortical thickness in whole brain except some areas in cingulate and insula decreased with aging. eTIV had positive correlation with the thickness of frontal, parietal, occipital and whole brain areas. However, the age effect was not shown in whole brain of the first tertile group and in cingulate areas of the third tertile group. eTIV had negative correlation with the thickness of cingulate in the third tertile group. Gender effects were shown in some areas in third tertile group, but it would be due to difference of head size. Conclusions These findings suggest that head size standardization might be done especially in older population and in studies of paralimbic areas.

The Effect of Manual Physical Therapy on Neck Disability Index in Myofascial Pain Syndromes: A Systematic Review

  • Kim, Chan-Myeong
    • Journal of the Korean Society of Physical Medicine
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    • v.15 no.4
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    • pp.21-28
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    • 2020
  • PURPOSE: The main purpose of this meta-analysis study was to identify the degree-of-effect size and the variables for the effects of manual physical therapy on myofascial pain syndrome. METHODS: This study collected six studies published between 2015.01.01 and 2019.12.31. The analysis result verified nine effect size data. The random-effect model was chosen because of the heterogeneity of the data. RESULTS: First, the full case showed the largest mean effect size of 2.297 (p < .001). Second, the size of the effect based on the fascial distortion model (FDM) intervention showed an effect size of 4.654 (p < .001). Third, the number of participants showed a 15 or less effect size of 2.612 (p > .058). The number of treatments showed a 10 less effect size of 2.844 (p > .129). The publication type showed a thesis effect size of 3.095 (p < .002). CONCLUSION: Manual physical therapy has a great effect on myofascial pain syndrome in the neck and shoulders, and that the effects differ according to the methods of intervention.

Effects of Grid Size on Noise Prediction Results of Road Traffic Noise Map (소음지도 격자크기가 도로교통 소음도 예측 결과에 미치는 영향)

  • Kim, Ji-Yoon;Park, In-Sun;Park, Chan-Youn;Park, Sang-Kyu;Ryu, Bong-Jo
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2007.05a
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    • pp.867-871
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    • 2007
  • Noise map is very efficient tool to evaluate the road traffic noise. However, calculation time and accuracy of noise map heavily depend on the grid size of noise map. In this study, effects of grid size on the prediction results of road traffic noise map have been investigated in detail for urban and rural areas, respectively, and efficient grid size for the noise map has been proposed.

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Effects of Particle Size Distribution of Alumina on Behaviors of Tape Casting (테이프 케스팅 거동에 미치는 알루미나의 입도분포의 영향)

  • 윤원균;김정주;조상희
    • Journal of the Korean Ceramic Society
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    • v.34 no.11
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    • pp.1173-1181
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    • 1997
  • Effects of particle size distribution of alumina ceramics on behaviors of tape casting were investigated with emphases on the rheological characteristic of slurry, green density, green sheet strength, and sintering density. For the control of particle size distribution of alumina, the commercial grade low soda alumina, which had different mean particle size of 3.58 ${\mu}{\textrm}{m}$ and 0.42 ${\mu}{\textrm}{m}$, were chosen and blended together. As results, the mixing of 80 wt% fine powder and 20 wt% coarse powder(designated to FC20) led to the increase of packing density and strength of green sheet, and made it easy to handle during processing without lowering of sintering density. Besides, the pseudoplastic behavior of slurry decreased with increase of the fraction of coarse alumina powder.

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Effects of Vaned Diffuser Shapes on the Flowfields of a Small-Size Turbo-Compressor (소형 터보압축기의 디퓨져 형상변화에 따른 유동특성 고찰)

  • Kim, H.-S.;Cha, K.;Kim, Youn J.
    • 유체기계공업학회:학술대회논문집
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    • 2000.12a
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    • pp.187-192
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    • 2000
  • The effects of diffuser shapes on the flowfields of a small-size turbo-compressor have been investigated by numerically and experimentally. It is important to optimal design of each elements for developing the small-size turbo-compressor Typical range of rotating speed of a small-size turbo-compressor is 40,000-70,000rpm. Numerical analyses are conducted to the rectangular and conical shapes of diffusers. Three-dimensional, steady, viscous governing equations are solved by SIMPLE algorithm. To prove the numerical results, experimental studies for the measurements of static pressure and temperature at the inlet and outlet boundaries are performed. Comparisons of these results are executed, and reasonable agreements are acquired.

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A Meta-Analysis on the Effectiveness of Smart-Learning in the field of General Education and Fisheries & Marine Education (일반교육과 수해양 교과교육에서 스마트교육미디어 효과성 연구)

  • HEO, Gyun;GU, Jung-Mo;HAN, Sang-Jun
    • Journal of Fisheries and Marine Sciences Education
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    • v.29 no.1
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    • pp.128-136
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    • 2017
  • The purpose of this research is to analyze the effects of smart learning in both general education and fisheries & marine education through meta-analysis. To find the effects size, we had collected 112 studies from graduation theses and journal articles. Followings are the results of the research: (a) Smart learning turns out to be more statistically effective comparing to traditional education. The total effect size of smart learning is .768 and the value of U3 is 61.50%. (b) There is no significant difference between general education and fisheries & marine education in the view of effect size. (c) There is a significant difference in subjects, type of publication, and size of members in experimental group. High school student group has the most effect size of smart learning.

Effects of Grid Size on Noise Prediction Results of Road Traffic Noise Map (소음지도 격자크기가 도로교통 소음도 예측결과에 미치는 영향)

  • Kim, Ji-Yoon;Park, In-Sun;Park, Chan-Youn;Park, Sang-Kyu
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.20 no.2
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    • pp.199-204
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    • 2010
  • Noise map is very efficient tool to evaluate the road traffic noise. However, calculation time and accuracy of noise map heavily depend on the grid size of noise map. In this study, effects of grid size on the prediction results of road traffic noise map have been investigated in detail for urban and rural areas, respectively, and efficient grid size for the noise map has been proposed.

Prediction of Crack Growth Retardation Behavior by Single Overload (단일 과대 하중에 의한 균열 성장 지연 거동 예측)

  • 송삼흥;최진호;김기석
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 1996.11a
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    • pp.928-932
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    • 1996
  • Single overload fatigue tests with overload sizes ranging from 50% and 100% have been performed to investing ate the fatigue crack growth retardation behavior. A modified and experimental method of Willenborg's model for prediction of crack growth retardation behavior has been developed, based on evaluations of equivalent plastic zone size (EPZS) changing its size along the overload plastic zone boundary. The minimum crack growth rates of each overload size are linearly decreased with overload size increasing, but fatigue lives extended by single overload are increasing much more unlike the crack growth rates. Comparisons of crack growth behavior predicted by EPZS model and Willenborg model have shown that the EPZS model accounts for overload effects better than Willenborg model. These effects include delayed retardation, large retardation region, minimum crack growth rate, and the increase rate of crack growth rate in the region crack growth rate recovered.

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Analyzing nonlinear mechanical-thermal buckling of imperfect micro-scale beam made of graded graphene reinforced composites

  • Khalaf, Basima Salman;Fenjan, Raad M.;Faleh, Nadhim M.
    • Advances in materials Research
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    • v.8 no.3
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    • pp.219-235
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    • 2019
  • This research is devoted to analyzing mechanical-thermal post-buckling behavior of a micro-size beam reinforced with graphene platelets (GPLs) based on geometric imperfection effects. Graphene platelets have three types of dispersion within the structure including uniform-type, linear-type and nonlinear-type. The micro-size beam is considered to be perfect (ideal) or imperfect. Buckling mode shape of the micro-size beam has been assumed as geometric imperfection. Modified couple stress theory has been used for describing scale-dependent character of the beam having micro dimension. Via an analytical procedure, post-buckling path of the micro-size beam has been derived. It will be demonstrated that nonlinear buckling characteristics of the micro-size beam are dependent on geometric imperfection amplitude, thermal loading, graphene distribution and couple stress effects.

The effects of the Size of Operator's Hand and the use of Foot on the Production Quantity and Product Quality (손의 크기와 발동작(動作)이 생산능률(生産能率)과 품질(品質)에 미치는 영향(影響))

  • Han, Sang-Deok;Lee, Sang-Yong
    • Journal of the Ergonomics Society of Korea
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    • v.3 no.1
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    • pp.3-11
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    • 1984
  • This study aims to investigate the effects of the size of operator's hand and the use of foot on the production quantity and product quality. To find out the facts the survey is conducted by measuring the hand size for the worker who is randomly chosen and by grouping them into the large hand size group and small hand size group on the base of the measuring data. The grouped operators are assigned to their job as usual, and their daily production quantities and qualities are measured. The survey shows that the production quantity of the small hand group are higher than the large hand group, and the number of defects of the small hand group are less than the large hand group.

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