• Title/Summary/Keyword: bias effect

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Chuna Manual Therapy for Postpartum Low Back Pain: Systematic Review (출산 후 요통에 대한 추나요법의 효과: 체계적 문헌고찰)

  • Cho, Ju-chan;Park, In-hwa;Hwang, Man-Suk;Heo, In
    • The Journal of Churna Manual Medicine for Spine and Nerves
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    • v.16 no.2
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    • pp.1-8
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    • 2021
  • Objectives This study aimed to evaluate the effect of chuna manual therapy (CMT) for postpartum low back pain using a systematic review. Methods We performed a literature search using 12 electronic databases up to the end of September 2021. We included randomized controlled trials (RCTs) that evaluated the effect of CMT in the treatment of postpartum low back pain. The risk of bias was evaluated using the Cochrane risk-of-bias tool. Results Four randomized controlled trials were reported statistically significant effect in pain VAS, ODI and JOA of chuna manual therapy compared with moxibution, electro acupuncture, hyperthermia or usual care. As a result of assessing the risk of bias tool, most of the contents of the evaluation items were not identified, so it was evaluated as an uncertain risk. Conclusions CMT may be effective in treating postpartum low back pain. However, evidence was limited due to the small sample size, lack of well-designed RCTs and regional bias. Further well-designed studies are required to obtain stronger evidence.

Relationship Between Sleep Quality and Depression Symptoms in Psychiatric Patients: Mediating Effect Interpretation Bias for Ambiguity and Anxiety Symptoms (정신건강의학과 환자의 수면의 질과 우울 증상의 관계: 모호함에 대한 해석 편향과 불안 증상의 매개효과)

  • Hyerin, Lee;Eunkyeong, Kim;Joonho, Choi;Seon-Cheol, Park
    • Korean Journal of Psychosomatic Medicine
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    • v.30 no.2
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    • pp.137-144
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    • 2022
  • Objectives : This study was designed to investigate the effect of sleep quality on depression symptoms and the mediating effect of interpretation bias and anxiety symptoms in psychiatric patients. Methods : Data accumulated for outpatients and inpatients in the Department of Mental Health Medicine at Hanyang University Guri Hospital were used. The measurement tools were Pittsburgh Sleep Quality Index (PSQI), Ambiguous/Unambiguous Situations Diary-Extended Version (AUSD-EX), Beck Anxiety Inventory (BAI), Beck Depression Inventory-II (BDI-II). Correlation analysis and bootstrapping analysis were conducted using SPSS 25.0 and SPSS Macro based on 162 patient data. Results : As a result of the study, the double mediating effect of interpretation bias for Ambiguity and anxiety symptoms was significant in the relationship between sleep quality and depression symptoms. Conclusions : In this study, it was confirmed that low sleep quality sequentially affects anxiety and depression symptoms through interpretation bias for ambiguity. Based on this, it is expected that the development of other psychiatric symptoms can be prevented by preferentially performing therapeutic intervention on preceding symptoms.

Consequentiality and Hypothetical Bias in Contingent Valuation Method: An Experimental Investigation (가상가치평가법에서의 결과수렴성과 가상편의)

  • Lee, Jinkwon;Hwang, Uk
    • Environmental and Resource Economics Review
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    • v.29 no.1
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    • pp.1-22
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    • 2020
  • While contingent valuation method (CVM) has been widely used for non-market valuations, it has been argued that it may suffer from hypothetical bias. However, if CVM respondents believe that their responses could affect the real consequence, the method could satisfy consequentiality. If a CVM satisfies a sufficiently high consequentiality, hypothetical bias could disappear as shown by some previous studies. In this study, we experimentally compare the willingness to pay (WTP) for donation of a relatively high consequentiality group with that of a relatively low consequentiality group for Korean university students. We find that both the existence probability and the size of hypothetical bias are lower for the high consequentiality group. This result implies that a CVM for a real policy including environmental policies could be free from hypothetical bias because its consequentiality would be relatively high, and warrants a future field study investigating the effect of consequentiality on hypothetical bias.

The Effects of Panax Ginseng on Streptozotocin-Induced Diabetic Rats: Meta Analysis

  • Kook, Se-Jeong;Kim, Gun-Hee;Choi, Ki-Heon
    • The Korean Journal of Applied Statistics
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    • v.22 no.1
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    • pp.107-114
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    • 2009
  • The present study was carried out to summarize the effect of ginseng in the experimental diabetic rats by meta-analysis related studies. The association measure to test effect of ginseng was the mean difference(MD) between group of rats induced streptozotocin(STZ) and group of rats induced STZ treated with ginseng about the considered effect factors. The level of FI, glucose and TG were significantly reduced(< 0.01), and the level of glycogen was significantly increased by treatment with ginseng (< 0.01) After checking the indication of publication bias for the combined MDs by using the funnel plots, the anti-diabetic effects of ginseng is clearly presented in FI, glucose, TG and glycogen (< 0.05).

Effect of Hydrogen in the Gate Insulator on the Bottom Gate Oxide TFT

  • KoPark, Sang-Hee;Ryu, Min-Ki;Yang, Shin-Hyuk;Yoon, Sung-Min;Hwang, Chi-Sun
    • Journal of Information Display
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    • v.11 no.3
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    • pp.113-118
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    • 2010
  • The effect of hydrogen in the alumina gate insulator on the bottom gate oxide thin film transistor (TFT) with an InGaZnO film as the active layer was investigated. TFT with more H-containing alumina films (TFT A) fabricated via atomic layer deposition using a water precursor showed higher stability under positive and negative bias stresses than that with less H-containing alumina deposited using ozone (TFT B). While TFT A was affected by the pre-vacuum annealing of GI, which resulted in $V_{th}$ instability under NBS, TFT B did not show a difference after the pre-vacuum annealing of GI. All the TFTs showed negative-bias-enhanced photo instability.

Switching behavior in Peramlloy/Niobium/Permalloy trilayer

  • Hwang, Tae-Jong;Kim, Dong Ho
    • Progress in Superconductivity and Cryogenics
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    • v.16 no.4
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    • pp.17-20
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    • 2014
  • We have investigated the effect of temperature and bias current on the stability of the inverse spin-switch effect in Permalloy(Py)/Nb/Permalloy pseudo spin-valves. The inverse spin-switch operates between two orientations of the ferromagnetic moments of Py layers; parallel (ON) and antiparallel-domain (OFF) state. Measuring time scans of the resistance changes between the ON and OFF state, ${\Delta}R_{ON-OFF}$, while alternating magnetic fields between the two states at various temperatures and bias currents, revealed that enhancement of ${\Delta}R_{ON-OFF}$ is a key factor to achieve successful operation of superconducting spin switch.

THE EFFECT OF THE REPEATABILITY FILE IN THE NIRS EATTY ACIDS ANALYSIS OF ANIMAL EATS

  • Perez Marin, M.D.;De Pedro, E.;Garcia Olmo, J.;Garrido Varo, A.
    • Proceedings of the Korean Society of Near Infrared Spectroscopy Conference
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    • 2001.06a
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    • pp.4107-4107
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    • 2001
  • Previous works have shown the viability of NIRS technology for the prediction of fatty acids in Iberian pig fat, but although the resulting equations showed high precision, in the predictions of new samples important fluctuations were detected, greater with the time passed from calibration development to NIRS analysis. This fact makes the use of NIRS calibrations in routine analysis difficult. Moreover, this problem only appears in products like fat, that show spectrums with very defined absorption peaks at some wavelengths. This circumstance causes a high sensibility to small changes of the instrument, which are not perceived with the normal checks. To avoid these inconveniences, the software WinISI 1.04 has a mathematic algorithm that consist of create a “Repeatability File”. This file is used during calibration development to minimize the variation sources that can affect the NIRS predictions. The objective of the current work is the evaluation of the use of a repeatability file in quantitative NIRS analysis of Iberian pig fat. A total of 188 samples of Iberian pig fat, produced by COVAP, were used. NIR data were recorded using a FOSS NIRSystems 6500 I spectrophotometer equipped with a spinning module. Samples were analysed by folded transmission, using two sample cells of 0.1mm pathlength and gold surface. High accuracy calibration equations were obtained, without and with repeatability file, to determine the content of six fatty acids: miristic (SECV$\sub$without/=0.07% r$^2$$\sub$without/=0.76 and SECV$\sub$with/=0.08% r$^2$$\sub$with/=0.65), Palmitic (SECV$\sub$without/=0.28 r$^2$$\sub$without/=0.97 and SECV$\sub$with/=0.24% r$^2$$\sub$with/=0.98), palmitoleic (SECV$\sub$without/=0.08 r$^2$$\sub$without/=0.94 and SECV$\sub$with/=0.09% r$^2$$\sub$with/=0.92), Stearic (SECV$\sub$without/=0.27 r$^2$$\sub$without/=0.97 and SECV$\sub$with/=0.29% r$^2$$\sub$with/=0.96), oleic (SECV$\sub$without/=0.20 r$^2$$\sub$without/=0.99 and SECV$\sub$with/=0.20% r$^2$$\sub$with/=0.99) and linoleic (SECV$\sub$without/=0.16 r$^2$$\sub$without/=0.98 and SECV$\sub$with/=0.16% r$^2$$\sub$with/=0.98). The use of a repeatability file like a tool to reduce the variation sources that can disturbed the prediction accuracy was very effective. Although in calibration results the differences are negligible, the effect caused by the repeatability file is appreciated mainly when are predicted new samples that are not in the calibration set and whose spectrum were recorded a long time after the equation development. In this case, bias values corresponding to fatty acids predictions were lower when the repeatability file was used: miristic (bias$\sub$without/=-0.05 and bias$\sub$with/=-0.04), Palmitic (bias$\sub$without/=-0.42 and bias$\sub$with/=-0.11), Palmitoleic (bias$\sub$without/=-0.03 and bias$\sub$with/=0.03), Stearic (bias$\sub$without/=0.47 and bias$\sub$with/=0.28), oleic (bias$\sub$without/=0.14 and bias$\sub$with/=-0.04) and linoleic (bias$\sub$without/=0.25 and bias$\sub$with/=-0.20).

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A Study on the Temperature Variation Characteristics of Power VDMOSFET (전력 VDMOSFET의 온도변화 특성에 관한 연구)

  • Lee, Woo-Sun
    • The Transactions of the Korean Institute of Electrical Engineers
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    • v.35 no.7
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    • pp.278-284
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    • 1986
  • Double-diffused metal oxide power semiconductor field effect transistors are used extensively in recent years in various circuit applications. The temperature variation of the drain current at a fixed bias shows both positive and negative resistance characteristics depending on the gate threshold voltage and gate-to source bias votage. In this paper, the decision method of the gate crossover voltage by the temperature variation and a new method to determine the gate threshold voltage graphecally are presented.

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