• Title/Summary/Keyword: negative bias

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The Influences of Deteriorated Visuo-spatial Attention Allocation Ability Caused by Aging on Emotional Perception Bias (노화에 의해 저하된 시공간 주의배분능력이 정서지각 편향성에 미치는 영향)

  • Kim, Sang-Yub;Jung, Jae-Bum;Nam, Ki-Chun
    • Science of Emotion and Sensibility
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    • v.23 no.4
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    • pp.3-20
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    • 2020
  • The purpose of this study was to investigate the effect of aging on visuo-spatial attention allocation ability and emotional perception bias. We used the useful field of view (UFOV) task to measure the visuo-spatial attention allocation ability and the emotional perception task to measure positive and negative emotional perception bias. A total of 48 participants took part in this study with 23 participants in the senior group and 25 in the junior group. The senior group showed slower response time and lower accuracy than the junior group in the UFOV task, indicating that the senior group had lower visuo-spatial attention allocation ability than the junior group. In the emotional perception task, the senior group showed both positive and negative emotional perception bias more than the junior group. The correlation analysis showed that the negative emotional perception bias for accuracy in the emotional perception task showed a positive correlation with the response time to the stimuli presented in the visual angle 30° in the UFOV task (r=.289). In addition, positive emotional perception bias for the accuracy in the emotional perception task showed a positive correlation with the accuracy of the stimuli presented in the visual angles 10°, 20°, and 30° in the UFOV task (r=.305, r=.322, and r=.299, respectively). However, it showed a negative correlation with the response time of the stimuli presented in the same location in the UFOV task (r=-.345, r=-.295, r=-.308). These results suggest that aging is associated with a decrease in the visuo-spatial attention allocation ability and perceptual bias toward positive and negative emotions. In addition, the positive and negative emotional perception biases associated with aging are potentially related to the reduced visuo-spatial attention allocation ability.

Deposition of diamond thin film by MPECVD method (마이크로웨이브 화학 기상 증착법을 이용한 다이아몬드 박막의 증착)

  • Sung Hoon Kim;Young Soo Park;Jo-Won Lee
    • Journal of the Korean Crystal Growth and Crystal Technology
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    • v.4 no.1
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    • pp.92-99
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    • 1994
  • Diamond thin film was deposited on n type (100) Si substrate by MPECVD(Microwave plasma Enhanced Chemical Vapor Deposition). For the increase in nucleation density of diamond, Si substrate was pretreated by diamond powder or negative bias voltage was applied to the substrate during the initial deposition. In the case of retreated Si substrate, the diamond thin film quality was enhanced with increasing the total pressure in the range of 20~150 Torr. For the negative bias voltage, the formation condition of the diamond was seriously affected by $CH_4$ concentration and total pressure. The formation condition will be discussed with electrical current of substrate generated by plasma ions which depend on $CH_4$concentration, bias voltage, and total pressure.

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Structural properties of carbon nanotubes: The effect of substrate-biasing (기판 바이어스에 따른 탄소 나노튜브의 구조적 물성)

  • Park, Chang-Kyun;Yun, Sung-Jun;Park, Jin-Seok
    • Proceedings of the KIEE Conference
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    • 2006.10a
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    • pp.36-37
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    • 2006
  • Both negative and positive substrate bias effects on the structural properties and field-emission characteristics are investigated. carbon nanotubes (CNTs) are grown on Ni catalysts employing an inductively-coupled plasma chemical vapor deposition (ICP-CVD) method. Characterization using various techniques, such as field-emission scanning electron microscopy (FESEM), high-resolution transmission electron microscopy (HRTEM), Auger spectroscopy (AES), and Raman spectroscopy, shows that the physical dimension as well as the crystal quality of CNTs grown can be changed and controlled by the application of substrate bias during CNT growth. It is for the first time observed that the prevailing 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 negative biasing would be more effectively role in the vertical-alignment of CNTs compared to positive biasing. However, the CNTs grown under the positively bias condition display much better electron emission capabilities than those grown under negative bias or without bias. The reasons for all the measured data regarding the structural properties of CNTs are discussed to confirm the correlation with the observed field-emissive properties.

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Temperature-Adaptive Back-Bias Voltage Generator for an RCAT Pseudo SRAM

  • Son, Jong-Pil;Byun, Hyun-Geun;Jun, Young-Hyun;Kim, Ki-Nam;Kim, Soo-Won
    • ETRI Journal
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    • v.32 no.3
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    • pp.406-413
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    • 2010
  • In order to guarantee the proper operation of a recessed channel array transistor (RCAT) pseudo SRAM, the back-bias voltage must be changed in response to changes in temperature. Due to cell drivability and leakage current, the obtainable back-bias range also changes with temperature. This paper presents a pseudo SRAM for mobile applications with an adaptive back-bias voltage generator with a negative temperature dependency (NTD) using an NTD VBB detector. The proposed scheme is implemented using the Samsung 100 nm RCAT pseudo SRAM process technology. Experimental results show that the proposed VBB generator has a negative temperature dependency of -0.85 $mV/^{\circ}C$, and its static current consumption is found to be only 0.83 ${\mu}A$@2.0 V.

A Low-Voltage Vibrational Energy Harvesting Full-Wave Rectifier using Body-Bias Technique (Body-Bias Technique을 이용한 저전압 진동에너지 하베스팅 전파정류회로)

  • Park, Keun-Yeol;Yu, Chong-Gun
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2017.10a
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    • pp.425-428
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    • 2017
  • This paper describes a full-wave rectifiers for energy harvesting circuit using a vibrational energy. The designed circuit is applied to the negative voltage converter with the body-bias technique using the Beta-multiplier so that the power efficiency is excellent even at the low voltage, and the comparator is designed as the bulk-driven type. The proposed circuit is designed with $0.35{\mu}m$ CMOS process, and The designed chip occupies $931{\mu}m{\times}785{\mu}m$.

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Effect of Negative Substrate Bias Voltage on the Microstructure and Mechanical Properties of Nanostructured Ti-Al-N-O Coatings Prepared by Cathodic Arc Evaporation

  • Heo, Sungbo;Kim, Wang Ryeol;Park, In-Wook
    • Journal of the Korean institute of surface engineering
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    • v.54 no.3
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    • pp.133-138
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    • 2021
  • Ternary Ti-X-N coatings, where X = Al, Si, Cr, O, etc., have been widely used for machining tools and cutting tools such as inserts, end-mills, and etc. Ti-Al-N-O coatings were deposited onto silicon wafer and WC-Co substrates by a cathodic arc evaporation (CAE) technique at various negative substrate bias voltages. In this study, the influence of substrate bias voltages during deposition on the microstructure and mechanical properties of Ti-Al-N-O coatings were systematically investigated to optimize the CAE deposition condition. Based on results from various analyses, the Ti-Al-N-O coatings prepared at substrate bias voltage of -80 V in the process exhibited excellent mechanical properties with a higher compressive residual stress. The Ti-Al-N-O (-80 V) coating exhibited the highest hardness around 30 GPa and elastic modulus around 303 GPa. The improvement of mechanical properties with optimized bias voltage of -80 V can be explained with the diminution of macroparticles, film densification and residual stress induced by ion bombardment effect. However, the increasing bias voltage above -80 V caused reduction in film deposition rate in the Ti-Al-N-O coatings due to re-sputtering and ion bombardment phenomenon.

Effects of Annealing on Electrical Characteristics of Double-Gated Silicon Nanosheet Feedback Field-Effect Transistors (더블게이트 실리콘 나노시트 피드백 전계효과 트랜지스터의 전기적 특성에 미치는 열처리 효과)

  • Hyojoo Heo;Yunwoo Shin;Jaemin Son;Seungho Ryu;Kyoungah Cho;Sangsig Kim
    • Journal of IKEEE
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    • v.27 no.4
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    • pp.418-424
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    • 2023
  • In this study, we examined the effects of annealing on electrical characteristics of double-gated silicon nanosheet (SiNS) feedback field effect transistors (FBFETs). When bias stresses were applied for 1000 s, the double-gated SiNS FBFETs were more affected by positive bias stresses than negative bias stresses regardless of the channel mode owing to the increase of interface traps caused by electrons in the inversion layers. After annealing at 300 ℃ for 10 mins, the devices were completely recovered to their original properties, and the characteristics did not change anymore when bias stresses were applied again for 1000 s.

The Relation Between Affective Style Based on EEG Asymmetry and Personality on Stress

  • Seo, Ssang-Hee;Lee, Jung-Tae;Chong, Young-Suk
    • Journal of Biomedical Engineering Research
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    • v.30 no.4
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    • pp.288-293
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    • 2009
  • This study investigates the relationship of affective style based on EEG asymmetry, personality, and psychological stress on stress. The experiment consists of three sessions: rest state, landscape scene, and horror film tasks. We used a short horror film to evoke stress. We classified affective style of the individual based on EEG alpha asymmetry: negative bias, positive bias and general. The participants in the negative bias group reported higher levels of stress on the neuroticism of the Big 5 model and Cohen's Perceived Stress Scale. These results demonstrate that participants with the propensity for negative affective style have a nervous temperament and are apt to be stressed.

Influence of Channel Thickness Variation on Temperature and Bias Induced Stress Instability of Amorphous SiInZnO Thin Film Transistors

  • Lee, Byeong Hyeon;Lee, Sang Yeol
    • Transactions on Electrical and Electronic Materials
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    • v.18 no.1
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    • pp.51-54
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    • 2017
  • TFTs (thin film transistors) were fabricated using a-SIZO (amorphous silicon-indium-zinc-oxide) channel by RF (radio frequency) magnetron sputtering at room temperature. We report the influence of various channel thickness on the electrical performances of a-SIZO TFTs and their stability, using TS (temperature stress) and NBTS (negative bias temperature stress). Channel thickness was controlled by changing the deposition time. As the channel thickness increased, the threshold voltage ($V_{TH}$) of a-SIZO changed to the negative direction, from 1.3 to -2.4 V. This is mainly due to the increase of carrier concentration. During TS and NBTS, the threshold voltage shift (${\Delta}V_{TH}$) increased steadily, with increasing channel thickness. These results can be explained by the total trap density ($N_T$) increase due to the increase of bulk trap density ($N_{Bulk}$) in a-SIZO channel layer.

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.