• Title/Summary/Keyword: Bias

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Optical properties of diamond-like carbon films deposited by ECR-PECVD method (ECR-PECVD 방법으로 증착한 Diamond-Like carbon 박막의 광 특성)

  • Kim, Dae-Nyoun;Kim, Ki-Hong;Kim, Hye-Dong
    • Journal of Korean Ophthalmic Optics Society
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    • v.9 no.2
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    • pp.291-299
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    • 2004
  • DLC films were deposited using the ECR-PECVD method with the fixed deposition condition, such as ECR power, methane and hydrogen gas-flow rates and deposition time, for various substrate bias voltage. We have investigated the ion bombardment effect induced by the substrate bias voltage on films during the deposition of film. The characteristic of the films were analyzed using the FTIR, Raman, and UV/Vis spectroscopy analysis shows that the amount of dehydrogenation in films was increased with the increase of substrate bias voltage and films thickness was decreased. Raman scattering analysis shows that integrated intensity ratio(ID/IG) of the D and G peak was increased as the substrate bias voltage increased and films hardness was increased. Optical transmittances of DLC film were decreased with increasing deposition time and substrate bias voltage. From these results, it can be concluded that films deposited at this experimental have the enhanced characteristics of DLC because of the ion bombardment effect on films during the deposition of film.

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Effect of Substrate Bias Voltage on DLC Films Prepared by ECR-PECVD (ECR-PECVD 방법으로 제작된 DLC 박막의 기판 Bias 전압 효과)

  • 손영호;정우철;정재인;박노길;김인수;김기홍;배인호
    • Journal of the Korean Vacuum Society
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    • v.9 no.4
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    • pp.328-334
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    • 2000
  • DLC (Diamond-Like Carbon) films were deposited by ECR-PECVD (electron cyclotron resonance plasma-enhanced chemical vapor deposition) method with the variation of substrate bias voltage under the others are constant except it. We have investigated the ion bombardment effect induced by the substrate bias voltage on films during the deposition of film. The characteristics of the film were analyzed using the Dektak surface profiler, SEM, FTIR spectroscopy, Raman spectroscopy and Nano Indentation tester. FTIR spectroscopy analysis shows that the amount of dehydrogenation in films was increased with the increase of substrate bias voltage and films thickness was decreased. Raman scattering analysis shows that integrated intensity ratio $(I_D /I_G)$ of the D and G peak was increased as the substrate bias voltage increased, and films hardness was increased. From these results, it can be concluded that films deposited at this experimental have the enhanced characteristics of DLC because of the ion bombardment effect on films during the deposition of film.

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Effect of Attention Feedback Awareness and Control Training on Attention Bias and Generalized Anxiety Symptoms in college students (주의 피드백 인식 및 조절 훈련이 대학생의 주의편향 및 범불안에 미치는 효과)

  • Kim, Su Jung;Shim, Eun-Jung
    • Korean Journal of School Psychology
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    • v.16 no.2
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    • pp.207-230
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    • 2019
  • This study examined the effect of Attention Feedback Awareness and Control Training(A-FACT) on attention bias and generalized anxiety symptoms in college students. A total of 31 college students with at least 10 points on the Generalized Anxiety Disorder 7-item (GAD-7) scale or at least 56 points on the Korean version of the Penn State Worry Questionnaire (K-PSWQ) with attention bias were randomly assigned to one of three groups: A-FACT( n = 11), Attention Bias Modification (ABM)(n = 10) and Active Placebo Control (APC)(n = 10). Participants in A-FACT group received real-time feedback on attention bias based on their Baseline Neutral Response time(BNR) during A-FACT using a dot probe task. Participants in the ABM group received standard ABM, and those in the APC performed a dot probe task that they were informed was a program to reduce attention bias, but feedback was not provided. A total of eight sessions was conducted twice a week over a 4-week period. After every two sessions, GAD-7, K-PSWQ and K-STAI were rated. The effect of attention bias modification training was rated by changes in the Attention Bias Score(ABS), and in GAD-7, K-PSWQ and K-STAI scores. The results of repeated measure ANOVA indicated that the A-FACT group showed a significant decrease in ABS as well as in GAD-7, K-PSWQ and K-STAI scores compared to the other groups. Current results suggest that self-regulatory control of attention, that is, recognition of bias through feedback in A-FACT, may be effective in alleviating attention bias and generalized anxiety symptoms by recognizing bias through feedback on bias in attention bias modification training.

Design Method for Shape Memory Alloy Actuator with Bias Spring (Bias 스프링을 이용한 형상기억합금 액츄에이터의 설계 방법)

  • Lee, Seung-Ki;Na, Seung-Woo
    • Journal of Sensor Science and Technology
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    • v.7 no.6
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    • pp.437-445
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    • 1998
  • The actuator using shape memory alloy spring with bias spring can act as a bidirectional actuator due to the restoring force of the bias spring. In the design of shape memory actuator with bias spring, the required design specifications are the generated force and the necessary stroke. To fulfill these requirements, shape memory alloy spring and bias spring should be designed carefully considering the specified application. In this paper, the novel design method for shape memory alloy actuator with bias spring, which does not require any assumptions from experience, has been proposed and verified by the test of fabricated shape memory alloy actuator. The experimental results show good agreements with calculated values, which guarantees the practical validity of our proposed design method.

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An Experiment : Distribution of the Adversity Quotient as a Reduction of Bias in Estimating Earnings

  • Riza PRADITHA;Lasty AGUSTUTY;Robert JAO;Andi RUSLAN;Nur AISYAH;Diah Ayu GUSTININGSIH
    • Journal of Distribution Science
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    • v.21 no.6
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    • pp.99-106
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    • 2023
  • Purpose: This study aims to analyze the distribution of the role of adversity quotient in the estimation bias of future earnings. Adversity quotient is a cognitive ability that can be distributed as a reducer of bias effects that occur in profit forecasting or investment decision making. Research design, data and methodology: The study designs a full factorial within-subject 2×3 as a laboratory experiment. The study subjects are 30 accounting students who are proxied as investors. Results: The results show that the estimated earnings made by investors experience anchoring-adjustment heuristic bias which means the initial value becomes a basic belief that influences the decisions taken by investors. However, this study also provides evidence that heuristic bias can be reduced by the presence of adversity quotient. Investors who have high adversity ability are abler to reduce the estimation bias when compared to investors who have medium and low adversity ability so the higher the difficulty ability possessed by investors, the less likely the occurrence of bias in decision making. Conclusion: Thus, the adversity quotient is proven to be distributed as a reducing opportunity from the bias that will occur in estimating future earnings or making investment decisions.

A Study on the Low Temperature Epitaxial Growth of $CoSi_2$ Layer by Multitarget Bias cosputter Deposition and Phase Sequence (Multitarget Bias Cosputter증착에 의한 $CoSi_2$층의 저온정합성장 및 상전이에 관한 연구)

  • Park, Sang-Uk;Choe, Jeong-Dong;Gwak, Jun-Seop;Ji, Eung-Jun;Baek, Hong-Gu
    • Korean Journal of Materials Research
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    • v.4 no.1
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    • pp.9-23
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    • 1994
  • Epitaxial $CoSi_2$ layer has been grown on NaCl(100) substrate at low deposition temperature($200^{\circ}C$) by multitarget bias cosputter deposition(MBCD). The phase sequence and crystallinity of deposited silicide as a function of deposition temperature and substrate bias voltage were studied by X-ray diffraction(XRD) and transmission electron microscopy(TEM) analysis. Crystalline Si was grown at $200^{\circ}C$ by metal induced crystallization(M1C) and self bias effect. In addition to, the MIC was analyzed both theoretically and experimentally. The observed phase sequence was $Co_2Si \to CoSi \to Cosi_2$ and was in good agreement with that predicted by effective heat of formation rule. The phase sequence, the CoSi(l11) preferred orientation, and the crystallinity had stronger dependence on the substrate bias voltage than the deposition temperature due to the collisional cascade mixing, the in-situ cleaning, and the increase in the number of nucleation sites by ion bombardment of growing surface. Grain growth induced by ion bombardment was observed with increasing substrate bias voltage at $200^{\circ}C$ and was interpreted with ion bombardment dissociation model. The parameters of $E_{Ar}\;and \alpha(V_s)$ were chosen to properly quantify the ion bombardment effect on the variation in crystallinty at $200^{\circ}C$ with increasing substrate bias voltage using Langmuir probe.

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A Newly Proposed Bias Stability Circuit for MMIC율s Yield Improvement (초고주파 집적회로의 수율향상을 위한 새로운 바이어스 안정화 회로)

  • 권태운;신상문;최재하
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.13 no.9
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    • pp.882-888
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    • 2002
  • This paper proposed a bias stability circuit that compensates the degradation of MMIC's performance for the variation of the process and temperature. The proposed bias circuit proved the superior effect compared with the conventional bias circuit using the constant current source. It designed and fabricated simultaneously two amplifier on one layout for comparison in same conditions. One is amplifier with conventional bias circuit using constant current source and the other is amplifier with proposed bias stability circuit. The chip was measured the microwave performances under process variation that classed the level NOM, MIN and MAX. The amplifier with a conventional bias circuit using constant current source has 6.4 dB gain variation and 7 mA Ids variation at 1.8 GHz, but the amplifier with the proposed bias circuit has the 2.1 dB gain variation and 3 mA Ids variation. As the result, MMIC having the proposed bias circuit shows the superior compensation of the quiescent point than the MMIC having the conventional bias circuit under the variations of the process and temperature and can improve the yield of the MMIC. The fabricated chip size is 1.2 mm $\times$ 1.4 mm.

The Assessment of Risk of Bias on Clinical Trials of Korean Medicine for Alopecia (탈모증의 한약제제 임상연구에 대한 비뚤림 위험 평가)

  • Ryu, Deok-hyun;Roh, Seok-sun
    • Journal of Haehwa Medicine
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    • v.24 no.1
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    • pp.25-36
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    • 2015
  • Objective : This study aims to evaluate a risk of bias by Risk of Bias tool and RoBANS(Risk of Bias Assessment tool for Non-randomized Study) tool for clinical trial papers proving treatment effect of herbs to alopecia and provides the newest reason of effectiveness of herbs to alopecia. Methos : Data were collected through electronic database including NDSL, KISS, KMBASE, Koreantk, OASIS, KoreaMed, KISTI, Pubmd, Cochrane CENTRAL and CINAHL. Two experts in Oriental Medince assessed risk of bias of randomized controlled trials by Cochrane group's Risk of Bias tool and non-randomized controlled trials by RoBANS tool after searching, reviewing and selecting papers. Results : Total number of selected trials is 20 including 4 randomized controlled trials, 13 non-randomized controlled trials and 3 case reports. This study evaluates the risk of bias of 17 papers including 4 randomized controlled trials and 13 non-randomized controlled trials except 3 case reports by risk of bias tool and RoBANS tool. All papers of randomized controlled trials are evaluated unclear for random sequence generation and allocation concealment as there are no word on them. And all papers of non-randomized controlled trials are evaluated unclear for blinding of outcome assessments and relatively low for others. Conclusion : We must try to specify concretely methods of allocation concealment after planning and practicing it for reducing a selection bias in randomized controlled trials. Also report a reason of missing value and blinding outcome assessments. And we have to agonize and mention methods of blinding of researchers for reducing a detection bias in non-randomized controlled trials.

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Uncertainty in Regional Climate Change Impact Assessment using Bias-Correction Technique for Future Climate Scenarios (미래 기상 시나리오에 대한 편의 보정 방법에 따른 지역 기후변화 영향 평가의 불확실성)

  • Hwang, Syewoon;Her, Young Gu;Chang, Seungwoo
    • Journal of The Korean Society of Agricultural Engineers
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    • v.55 no.4
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    • pp.95-106
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    • 2013
  • It is now generally known that dynamical climate modeling outputs include systematic biases in reproducing the properties of atmospheric variables such as, preciptation and temerature. There is thus, general consensus among the researchers about the need of bias-correction process prior to using climate model results especially for hydrologic applications. Among the number of bias-correction methods, distribution (e.g., cumulative distribution fuction, CDF) mapping based approach has been evaluated as one of the skillful techniques. This study investigates the uncertainty of using various CDF mapping-based methods for bias-correciton in assessing regional climate change Impacts. Two different dynamicailly-downscaled Global Circulation Model results (CCSM and GFDL under ARES4 A2 scenario) using Regional Spectial Model for retrospective peiod (1969-2000) and future period (2039-2069) were collected over the west central Florida. Total 12 possible methods (i.e., 3 for developing distribution by each of 4 for estimating biases in future projections) were examined and the variations among the results using different methods were evaluated in various ways. The results for daily temperature showed that while mean and standard deviation of Tmax and Tmin has relatively small variation among the bias-correction methods, monthly maximum values showed as significant variation (~2'C) as the mean differences between the retrospective simulations and future projections. The accuracy of raw preciptiation predictions was much worse than temerature and bias-corrected results appreared to be more significantly influenced by the methodologies. Furthermore the uncertainty of bias-correction was found to be relevant to the performance of climate model (i.e., CCSM results which showed relatively worse accuracy showed larger variation among the bias-correction methods). Concludingly bias-correction methodology is an important sourse of uncertainty among other processes that may be required for cliamte change impact assessment. This study underscores the need to carefully select a bias-correction method and that the approach for any given analysis should depend on the research question being asked.

Attentional Bias to Emotional Stimuli and Effects of Anxiety on the Bias in Neurotypical Adults and Adolescents

  • Mihee Kim;Jejoong Kim;So-Yeon Kim
    • Science of Emotion and Sensibility
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    • v.25 no.4
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    • pp.107-118
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    • 2022
  • Human can rapidly detect and deal with dangerous elements in their environment, and they generally manifest as attentional bias toward threat. Past studies have reported that this attentional bias is affected by anxiety level. Other studies, however, have argued that children and adolescents show attentional bias to threatening stimuli, regardless of their anxiety levels. Few studies directly have compared the two age groups in terms of attentional bias to threat, and furthermore, most previous studies have focused on attentional capture and the early stages of attention, without investigating further attentional holding by the stimuli. In this study, we investigated both attentional bias patterns (attentional capture and holding) with respect to negative emotional stimulus in neurotypical adults and adolescents. The effects of anxiety level on attentional bias were also examined. The results obtained for adult participants showed that abrupt onset of a distractor delayed attentional capture to the target, regardless of distractor type (angry or neutral faces), while it had no effect on attention holding. In adolescents, on the other hand, only the angry face distractor resulted in longer reaction time for detecting a target. Regarding anxiety, state anxiety revealed a significant positive correlation with attentional capture to a face distractor in adult participants but not in adolescents. Overall, this is the first study to investigate developmental tendencies of attentional bias to negative facial emotion in both adults and adolescents, providing novel evidence on attentional bias to threats at different ages. Our results can be applied to understanding the attentional mechanisms in people with emotion-related developmental disorders, as well as typical development.