• Title/Summary/Keyword: Experimental bias

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Exploratory Study: A Modification Training Method of Attentional Bias Toward Safety

  • Gao, Jingqi;Wu, Xiang;Luo, Xiaowei;Zhang, Ao
    • Safety and Health at Work
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    • v.12 no.3
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    • pp.346-350
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    • 2021
  • Background: The high sensitivity of individuals toward safety information in production activities, that is, attentional bias toward safety (ABS), can positively predict safe behaviors. It has become a hot topic in current organizational safety behavior research. However, there is no literature on its modification method. Methods: Based on the modified dot-probe task, we designed a modification training method of ABS. The training method required subjects to respond to the location of detection points that presented after safety stimulus and neutral stimulus pictures. Subjects' attentional bias values of safety and neutral pictures were measured during the experiment. Twenty-one students were selected and divided into a control group and training group to gain comparable results. Results: A novel training method was developed in this study to promote the efficacy of safety stimulus by activating ABS of the subjects. Moreover, repeated trainings and preacquired relative knowledge can enhance this effect. Conclusion: This study develops an experimental approach to evaluate the effectiveness of safety education and safety training, and also provides a new research idea for accident prevention.

A Systematic Review of Acupuncture for Oculomotor Nerve Palsy

  • Ku, Yong Ho;Kang, Jae Hui;Kong, Hae Jin;Ryu, Hwa Yeon;Lee, Hyun
    • Journal of Acupuncture Research
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    • v.36 no.2
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    • pp.59-71
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    • 2019
  • Acupuncture treatment for oculomotor nerve palsy has been increasing recently. This study analyzed randomized controlled trials (RCTs) and case reports, using the Cochrane risk of bias tool to investigate the efficacy of acupuncture therapy for oculomotor nerve palsy. This analysis was performed on March 7, 2019, using online databases (PubMed, Cochrane, NDSL, OASIS, CNKI) where 208 articles were retrieved. Of these, there were 18 case reports and 18 RCTs that matched the inclusion criteria, of which 32 studies used acupuncture as the primary intervention, 1 used pharmacopuncture, 1 used fire-needling, and 1 used electroacupuncture. The most commonly used acupoints were BL1, BL2, ST2, TE23, Ex-HN5, LI4, GB14, ST36, GB20 and GB1. Significant findings were reported in all RCTs. Six adverse events were reported in 3 RCTs, with no effect on the outcome. No side effects were reported in the case reports. The risk-of-bias analysis showed that the articles did not report the experimental protocol used and it was not clear whether the study was blinded. Hence, it was difficult to assess the risk of bias. Analysis of 36 studies showed that acupuncture therapy for oculomotor nerve palsy was effective in many cases. It was difficult to evaluate the potential bias.

Design, Linear and Efficient Analysis of Doherty Power Amplifier for IMT-2000 Base Station (IMT-2000 기지국용 도허티 전력증폭기의 설계 및 선형성과 효율 분석)

  • Kim Seon-Keun;Kim Ki-Moon
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.9 no.2
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    • pp.262-267
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    • 2005
  • During several method of improvement efficient, We analyzed Doherty Amplifier That used by simple circuit and 180w PEP LDMOS to analyze improvement of efficient and linearity. We for testing performance of Doherty Amplifier compared with Balanced Class AB, the experimental results show when Peaking Amp $V_gs.P$=1.53V, the efficiency is increased at Maximum 11.6$\%$. After finding optimum bias point of linearity improvement by manual tuning gate bias, when WCDMA 4FA $V_gs.P$=3.68V IMSR could be increased maximum 3.34dB. especially, when we match bias point of Peaking amp at 1.53V, we could get a excellent efficiency increase and have fUR under -3203c at output power 43dBm.

Statistical bias indicators for the long-term displacement of steel-concrete composite beams

  • Moreno, Julian A.;Tamayo, Jorge L.P.;Morsch, Inacio B.;Miranda, Marcela P.;Reginato, Lucas H.
    • Computers and Concrete
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    • v.24 no.4
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    • pp.379-397
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    • 2019
  • Steel-concrete composite beams are widely employed in constructions and their performance at the serviceability stage is of concern among practitioners and design regulations. In this context, an accurate evaluation of long-term deflections via various rheological concrete models is needed. In this work, the performance and predict capability of some concrete creep and shrinkage models ACI, CEB, B3, FIB and GL2000 are ascertained, and compared by using statistical bias indicators. Ten steel-concrete composite beams with existing experimental and numerical results are then modeled for this purpose. The proposed modeling technique uses the finite element method, where the concrete slab and steel beam are modeled with shell finite elements. Concrete is considered as an aging viscoelastic material and cracking is treated with the common smeared approach. The results show that when the experimental ultimate shrinkage strain is used for calibration, all studied rheological models predict nearly similar deflections, which agree with the experimental data. In contrast, significance differences are encountered for some models, when none calibration is made prior to. A value between twenty and thirty times the cracking strain is recommended for the ultimate tensile strain in the tension stiffening model. Also, increasing the relative humidity and decreasing the ambient temperature can lead to a substantial reduction of slab cracking for beams under negative flexure. Finally, there is not a unique rheological model that clearly excels in all scenarios.

Relative Influence of Surface and Interfacial Defects in Hydrothermally Grown Nanostructured ZnO (수열 합성된 나노구조를 갖는 ZnO 에 대한 표면 및 계면 결함의 상대적인 영향)

  • Park, Cheolmin;Lee, Jihye;So, Hye-Mi;Chang, Won Seok
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.38 no.10
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    • pp.831-835
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    • 2014
  • The relative concentration of surface and interfacial defects in hydrothermally grown ZnO nanostructures was investigated by a comparison of two samples having different growth temperatures via bias voltage sweep rate under laser illumination of 405 and 355 nm. The current of small ZnO nanostructures (growth temperature of $75^{\circ}C$) decreased when induced more slowly bias voltage sweep rate under the laser illumination. In contrast, the current of large ZnO nanostructures (growth temperature of $90^{\circ}C$) increased. This difference in currents indicates the relation of relative defects concentration between surface and interfacial defects of ZnO nanostructure. Our experimental approach has potential applicability in the analysis of influence on defects in ZnO devices.

Accuracy Evaluation of DEM generated from Satellite Images Using Automated Geo-positioning Approach

  • Oh, Kwan-Young;Jung, Hyung-Sup;Lee, Moung-Jin
    • Korean Journal of Remote Sensing
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    • v.33 no.1
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    • pp.69-77
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    • 2017
  • S The need for an automated geo-positioning approach for near real-time results and to boost cost-effectiveness has become increasingly urgent. Following this trend, a new approach to automatically compensate for the bias of the rational function model (RFM) was proposed. The core idea of this approach is to remove the bias of RFM only using tie points, which are corrected by matching with the digital elevation model (DEM) without any additional ground control points (GCPs). However, there has to be a additional evaluation according to the quality of DEM because DEM is used as a core element in this approach. To address this issue, this paper compared the quality effects of DEM in the conduct of the this approach using the Shuttle Radar Topographic Mission (SRTM) DEM with the spatial resolution of 90m. and the National Geographic Information Institute (NGII) DEM with the spatial resolution of 5m. One KOMPSAT-2 stereo-pair image acquired at Busan, Korea was used as experimental data. The accuracy was compared to 29 check points acquired by GPS surveying. After bias-compensation using the two DEMs, the Root Mean Square (RMS) errors were less than 6 m in all coordinate components. When SRTM DEM was used, the RMSE vector was about 11.2m. On the other hand, when NGII DEM was used, the RMSE vector was about 7.8 m. The experimental results showed that automated geo-positioning approach can be accomplished more effectively by using NGII DEM with higher resolution than SRTM DEM.

Effect of Virtual Reality Exposure and Web-based Cognitive Intervention Integrated Program on Social Anxiety Disorder (발표상황에 대한 가상현실노출과 웹기반 인지적 개입의 통합 프로그램 효과 검증)

  • Park, Ki-Woo;Yoon, Hyae-Yeong
    • Journal of the Korea Convergence Society
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    • v.13 no.1
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    • pp.1-12
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    • 2022
  • In this study, the effect of VR exposure programs integrated with web-based cognitive restructuring education on reducing social anxiety was confirmed. The experimental group (n=12) received a 10~15 minute session of web-based cognitive intervention and a 20-minute session of virtual reality exposure therapy. The comparison group (n=15) received a 10~15 minute session of web-based speech education and a 20-minute session of virtual reality exposure therapy. After 4 weeks, the experimental group had an increase in positive interpretation bias, a decrease in negative interpretation bias, and a decreased level of social anxiety. These results suggest that the combination of self-help form of web-based cognitive intervention in the treatment of social anxiety disorder can improve the therapeutic effect of VRET.

Simulations of Capacitively Coupled Plasmas Between Unequal-sized Powered and Grounded Electrodes Using One- and Two-dimensional Fluid Models

  • So, Soon-Youl
    • KIEE International Transactions on Electrophysics and Applications
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    • v.4C no.5
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    • pp.220-229
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    • 2004
  • We have examined a technique of one-dimensional (1D) fluid modeling for radio-frequency Ar capacitively coupled plasmas (CCP) between unequal-sized powered and grounded electrodes. In order to simulate a practical CCP reactor configuration with a grounded side wall by the 1D model, it has been assumed that the discharge space has a conic frustum shape; the grounded electrode is larger than the powered one and the discharge space expands with the distance from the powered electrode. In this paper, we focus on how much a 1D model can approximate a 2D model and evaluate their comparisons. The plasma density calculated by the 1D model has been compared with that by a two-dimensional (2D) fluid model, and a qualitative agreement between them has been obtained. In addition, 1D and 2D calculation results for another reactor configuration with equal-sized electrodes have also been presented together for comparison. In the discussion, four CCP models, which are 1D and 2D models with symmetric and asymmetric geometries, are compared with each other and the DC self-bias voltage has been focused on as a characteristic property that reflects the unequal electrode surface areas. Reactor configuration and experimental parameters, which the self-bias depends on, have been investigated to develop the ID modeling for reactor geometry with unequal-sized electrodes.

Instability of Electric Characteristics in Hydrogenated Amorphous Carbon (수소화된 비정질 탄소박막에서 전기적 특성의 불안정성)

  • Kang, Sung Soo;Lee, Won Jin
    • Journal of Korean Ophthalmic Optics Society
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    • v.4 no.2
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    • pp.105-111
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    • 1999
  • This paper presents experimental results on the electrical properties of hydrogenated amorphous carbon films(a-C:H) prepared by PECVD. DC conductance of a-C:H was measured as a function of temperatures in the range of 100 to 423K. We studied two a-C:H films: one was well explained by the Mott's Variable Range Hopping(VRH) rule, but the other sample did not follow it. However, the conduction data of second sample were well fitted to Shimakawa's Multi-Phonon Hopping(MPH) model according to which conductivity is proportional to $T^M$ with m=15-17. but, in our samples, m was 10-12. Also a-C:H showed several bias effects like relaxation of conductance, bias-dependent conductance and the change of conductance slope in 1n(${\sigma}{\sqrt{T}}$) vs. $T^{1/4}$ plot. In this study we interpret these data by bias-dependent detrapping model.

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Reactive ion etching of InP using $BCl_3/O_2/Ar$ inductively coupled plasma ($BCl_3/O_2/Ar$ 유도결합 플라즈마를 이용한 InP의 건식 식각에 관한 연구)

  • 이병택;박철희;김성대;김호성
    • Journal of the Korean Vacuum Society
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    • v.8 no.4B
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    • pp.541-547
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    • 1999
  • Reactive ion etching process for InP using BCl3/O2/Ar high density inductively coupled plasma was investigated. The experimental design method proposed by the Taguchi was utilized to cover the whole parameter range while maintaining reasonable number of actual experiments. Results showed that the ICP power and the chamber pressure were the two dominant parameters affectsing etch results. It was also observed that the etch rate decreased and the surface roughness improved as the ICP power and the bias voltage increased and as the chamber pressure decreased. The Addition of oxygen to the gas mixture drastically improved surface roughness by suppressing the formation of the surface reaction product. The optimum condition was ICP power 600W, bias voltage -100V, 10% $O_2$, 6mTorr, and $180^{\circ}C$, resulting in about 0.15$\mu\textrm{m}$ etch rate with smooth surfaces and vertical mesa sidewalls Also, the maximum etch rate of abut 4.5 $\mu\textrm{m}$/min was obtained at the condition of ICP power 800W, bias voltage -150V, 15% $O_2$, 8mTorr and $160^{\circ}C$.

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