• Title/Summary/Keyword: bias effect

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Fascia Chuna Therapy for Piriformis Syndrome: A Review of Clinical Study (이상근증후군의 근막 추나 요법에 대한 문헌 고찰 연구 보고)

  • Park, In-hwa
    • The Journal of Churna Manual Medicine for Spine and Nerves
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    • v.16 no.2
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    • pp.39-45
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    • 2021
  • Objectives The purpose of this study was to assess the effect of fascia chuna therapy in the treatment of piriformis syndrome. Methods A literature search was conducted using 8 databases to identify all randomized controlled clinical trials (RCTs) that investigated fascia chuna therapy as a treatment for piriformis syndrome. The selected studies are analyzed the risk of bias through Cochrane risk of bias tool. Results Among 37 articles that were searched, 3 RCTs met our inclusion criteria and were included in this analysis. These studies demonstrated positive results of Fascia Chuna Therapy with respect to the reduction of pain scale and functional scale compared with other treatment methods. Conclusions Based on results, fascia chuna therapy could be effective in piriformis syndrome. However there are limitations that the number of selected studies was small and risk of bias was unclear. More well-designed RCTs are required to provide clearer evidence.

Effect of Lactobacillus Base Probiotics Feeding on the Growth Performance, Blood Parameters and Cecal Lactic Acid Bacteria of Broiler Chicken: Meta-analysis (Lactobacillus를 주성분으로 하는 생균제의 급여가 육계의 성장성적, 혈액성분 및 장내 유산균에 미치는 효과: 메타분석)

  • Choi, Nag-Jin;Hwang, In-Ho;Park, Chul;Kim, Dae-Cheol;Baek, Seoung-Woo;Moon, Sang-Ho;Cho, Won-Mo;Hong, Seong-Koo
    • Korean Journal of Organic Agriculture
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    • v.19 no.4
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    • pp.565-575
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    • 2011
  • Recently, the use of antibiotics to improve animal productivity in livestock industry was strictly restricted. For these reason, probiotics have been regarded as one of promising materials for an antibiotic alternative. In this study, we investigated how the probiotics influences on the performance of broiler chicken via meta-analysis. Eighteen researches from 1997 to 2010 were used for meta-analysis. The standard summary effects were calculated via fixed effect model and random effect model (Borenstein et al., 2009). Heterogeneity was calculated by using the Cochran's Q statistics (Kook et al., 2009) and publication bias was calculated via Egger's regression (Lee et al., 2011). In fixed model average daily gain, body weight serum protein content and cecal LAB showed positive effect significantly. Feed intake, feed/gain and serum cholesterol showed significant negative effect. In serum triglyceride, negative effect was found but significance was not shown. In random model, average daily gain body weight and cecal LAB showed positive effects with significance and feed/gain and serum cholesterol represented significant negative effects. Publication bias was found only in feed/gain.

Structural and Field-emissive Properties of Carbon Nanotubes Produced by ICP-CVD: Effects of Substrate-Biasing (ICP-CVD 방법으로 성장된 탄소 나노튜브의 구조적 특성 및 전계방출 특성: 기판전압 인가 효과)

  • Park, C.K.;Kim, J.P.;Yun, S.J.;Park, J.S.
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.56 no.1
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    • pp.132-138
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    • 2007
  • Carbon nanotubes (CNTs) arc grown on Ni catalysts employing an inductively-coupled plasma chemical vapor deposition (ICP-CVD) method. The structural and field-emissive properties of the CNTs grown are characterized in terms of the substrate-bias applied. Characterization using the various techniques, such as field-omission scanning electron microscopy (FESEM), high-resolution transmission electron microscopy (HRTEM), Auger spectroscopy (AES), and Raman spectroscopy, shows that the structural properties of the CNTs, including their physical dimensions and crystal qualities, as well as the nature of vertical growth, are strongly dependent upon the application of substrate bias during CNT growth. It is for the first time observed that the provailing growth mechanism of CNTs, which is either due to tip-driven growth or based-on-catalyst growth, may be influenced by substrate biasing. It is also seen that negatively substrate-biasing would promote the vertical-alignment of the CNTs grown, compared to positively substrate-biasing. However, the CNTs grown under the positively-biased condition display a higher electron-emission capability than those grown under the negatively-biased condition or without any bias applied.

The Effects of Grain Size on the Degradation Phenomena of PZT Ceramics (입자의 크기가 PZT 세라믹스의 열화현상에 미치는 영향)

  • 정우환;김진호;조상희
    • Journal of the Korean Ceramic Society
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    • v.29 no.1
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    • pp.65-73
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    • 1992
  • The effect of grain size on the time-dependent piezoelectrice degradation of a poled PZT of MPB composition Pb0.988Sr0.012 (Zr0.52Ti0.48)O3 with 2.4 mol% of Nb2O5 was studied, and the degradation mechanism was discussed. Changes in the internal bias field and the internal stress both responsible for the time-dependent degradation of poled PZT were examined by the polarization reveral technique, XRD and Vickers indentation, respectively. The piezoelectric degradation increased with increasing time and grain size, and the internal bias field due to space charge diffusion decreased with increasing grain size of poled PZT. The internal bias field, however, was almost insensitive to the degradation time regardless of the grain size. On the other hand, both the x-ray diffraction peak intensity ratio of (002) to (200) and the fracture behavior including the crack propagation support that the ferroelectric domain rearrangement of larger grain size showed rapid relaxation of the internal stress compared with smaller one, which is thought the origin of the larger piezoelectric degradation in the former. In conclusion, the contribution of space charge diffusion on the piezoelectric degradation of PZT is strongly dependent on both the grain size and the composition. Thus, the relaxation of internal stress due to the ferroelectric domain rearrangement as well as the amount and time-dependence of the internal bias field due to space charge diffusion should be considered simultaneously in the degradation mechanism of PZT.

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Electrical and Optical Properties of GZO Thin Films Using Substrate Bias Voltage for Solar Cell (기판 바이어스 전압을 이용한 태양전지용 GZO 박막의 전기적, 광학적 특성)

  • Kwon, Soon-Il;Park, Seung-Bum;Lee, Seok-Jin;Jung, Tae-Hwan;Yang, Kea-Jun;Park, Jea-Hwan;Choi, Won-Seok;Lim, Dong-Gun
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2008.11a
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    • pp.103-104
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    • 2008
  • In this paper we report upon an investigation into the effect of DC bias voltage on the electrical and optical properties of Gallium doped zinc oxide (GZO) film. GZO films were deposited on glass substrate without substrate temperature by RF magnetron sputtering from a ZnO target mixed with 5 wt% $Ga_2O_3$. we investigated sample properties of bias voltage change in 0 to -60 V. We were able to achieve as low as $5.89\times10^{-4}$ ${\Omega}cm$ and transmittance over 87%. without substrate temperature.

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Influence of Neutral Particle Beam Energy on the Structural Properties of Amorphous Carbon Films Prepared by Neutral Particle Beam Assisted Sputtering

  • Lee, Dong-Hyeok;Jang, Jin-Nyeong;Gwon, Gwang-Ho;Yu, Seok-Jae;Lee, Bong-Ju;Hong, Mun-Pyo
    • Proceedings of the Korean Vacuum Society Conference
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    • 2011.02a
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    • pp.194-194
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    • 2011
  • The effects of argon neutral beam (NB) energy on the amorphous carbon (a-C) films were investigated, while the a-C films were deposited by neutral particle beam assisted sputtering (NBAS) system. The energy of neutral particle beam can be controlled by reflector bias voltage directly as a unique operating parameter in this system. The deposition characteristics of the films investigated of Raman spectra, UV-visible spectroscopy, electrical conductivity, stress measurement system, and ellipsometer indicate the properties of amorphous carbon films can be manipulated by only NB energy (or reflector bias voltage) without changing any other process parameters. We report the effect of reflector bias voltage in the range from 0 to -1KV. By the increase of the reflector bias voltage, the amount of cross-linked sp2 clusters as well as the sp3 bonding in the a-C film coated by the NBAS system can be increased effectively and the composition of carbon thin films can be changed from nano-crystalline graphite phase to amorphous carbon phase.

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The Properties of Low Hydrogen Content α-Si Thin Film Using DC-bias Enhanced or Addition of H2Gas in Mesh-type PECVD System (Mesh-type PECVD를 이용한 DC-bias인가 및 수소가스 첨가에 따른 저수소화 비정질 실리콘 박막에 관한 연구)

  • Ryu, Se-Won;Gwon, Do-Hyeon;Park, Seong-Gye;Nam, Seung-Ui;Kim, Hyeong-Jun
    • Korean Journal of Materials Research
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    • v.12 no.4
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    • pp.235-239
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    • 2002
  • In this study mesh-type PECVD system was suggested to minimize the hydrogen concentration. The main structural difference between the triode system and a conventional system is that, a third electrode, a mesh, is inserted between the powered and the ground electrode. We investigated several conditions to compare with conventional PECVD. The main effect of mesh was to minimize the substrate damage by ion bombardment and to enhance the surface reaction to induce hydrogen desorption. It was also found that hydrogen concentration decreased but deposition rate increased as increasing applied bias. Applied DC-bia s enhanced sputtering process. Intense ion bombardment causes the weakly bonded hydrogen or hydrogen-containing species to leave the growing film and increased adatom mobility. Furthermore, addition of hydrogen gas enhance the surface diffusion of adatom.

Cognitive Biases and Their Effects on Information Behaviour of Graduate Students in Their Research Projects

  • Behimehr, Sara;Jamali, Hamid R.
    • Journal of Information Science Theory and Practice
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    • v.8 no.2
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    • pp.18-31
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    • 2020
  • Cognitive biases can influence human information behaviour and decisions made in information behaviour and use. This study aims to identify the biases involved in some aspects of information behaviour and the role they play in information behaviour and use. Twenty-five semi-structured face-to-face interviews were conducted in an exploratory qualitative study with graduate (MA and PhD) students who were at the stage of their dissertation/thesis research. Eisenberg & Berkowitz Big6TM Skills for Information Literacy was adopted as a framework for interviews and the analysis was done using grounded theory coding method. The findings revealed the presence of twenty-eight biases in different stages of information behaviour, including availability bias (affects the preference for information seeking strategies), attentional bias (leads to biased attention to some information), anchoring effect (persuades users to anchor in special parts of information), confirmation bias (increases the tendency to use information that supports one's beliefs), and choice-supportive bias (results in confidence in information seeking processes). All stages of information seeking were influenced by some biases. Biases might result in a lack of clarity in defining the information needs, failure in looking for the right information, misinterpretation of information, and might also influence the way information is presented.

Large Area Diamond Nucleation and Si (001) Using Magnetoactive Microwave Plasma Chemical Vapor Deposition

  • Hyeongmin Jeon;Akimitsu Hatta;Hidetoshi Suzuki;Nam Jiang;Jaihyung Won;Toshimichi Ito;Takatomo Sasaki;Chongmu Lee;Akio Hiraki
    • The Korean Journal of Ceramics
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    • v.3 no.3
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    • pp.159-162
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    • 1997
  • Diamond was uniformly nucleated on large area Si(001) substrate (3cm$\times$4cm) using the low pressure magnetoactive microwave plasma chemical vapor deposition. $CH_4/He$ gas mixture was used as source gas in order to obtain high radical density in the nucleation enhancement step. $CH_3$radical density was measured by means of infrared laser absorption spectroscopy. The effect of substrate bias voltage on diamond nucleation was examined. The results showed that a suitable positive bias voltage appled to the substrate with respect to the chamber could enhance diamond nucleation while a negative bias voltages leaded to deposition of only non-diamond phase carbon.

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The Effect of Local-Global Environmental Bias on the Type Ia Supernova Host Galaxy Studies

  • Kim, Young-Lo;Sullivan, Mark;Smith, Mathew;Lee, Young-Wook
    • The Bulletin of The Korean Astronomical Society
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    • v.41 no.1
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    • pp.32.4-33
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    • 2016
  • Recent studies suggest that the difference between global and local properties of galaxies (the local-global environmental (LoG) bias) might be important in the Type Ia supernova (SN Ia) host galaxy studies. Obtaining local spectroscopic properties of hosts at high redshift, however, is challenging. Here we will introduce a more efficient way to conduct this study by only using photometric data. We find that when we restrict a sample to the hosts whose stellar mass is less than $10^{10}$ $M_{\odot}$, a sample without LoG bias is efficiently selected. From the sample without LoG bias, we confirm that SNe Ia in locally star-forming environment are $0.103{\pm}0.010mag$ and $0.085{\pm}0.012mag$ fainter than those in locally passive region, for MLCS2k2 and SALT2, respectively. Because of ~6 times larger sample that covers much wider redshift range, our results are far more significant statistically, $10.3{\sigma}$ for MLCS2k2 and $7.1{\sigma}$ for SALT2, than previous results.

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