• 제목/요약/키워드: positive bias stress

검색결과 69건 처리시간 0.029초

The effects of health care programs for gestational diabetes mellitus in South Korea: a systematic review

  • Park, Seo Jin;Lee, Jina
    • 여성건강간호학회지
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    • 제26권4호
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    • pp.274-284
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    • 2020
  • Purpose: The purpose of this study was to investigate the effects and characteristics of health care programs for pregnant women with gestational diabetes mellitus (GDM) in Korea. Methods: This study was conducted according to the Cochrane Collaboration's systematic literature review handbook and the Preferred Reporting Items for Systematic Reviews and Meta-Analyses reporting guideline. We searched eight international and domestic electronic databases for relevant studies. Two reviewers independently selected the studies and extracted data. For each study, information on the research method, participants, characteristics of the program, and results were extracted using a previously established coding table. The National Evidence-based Healthcare Collaborating Agency's risk of bias assessment tool for non-randomized studies was used to assess the risk of bias of the included articles. A qualitative review of the selected studies was performed because the interventions differed considerably and the measured outcomes varied. Results: Out of 128 initially identified papers, seven were included in the final analysis. The risk of bias was evaluated as generally low. Health care programs for pregnant women with GDM showed positive effects on blood glucose control. Anxiety and depression were reduced, and self-management and self-care behavior, self-efficacy, and maternal identity improved. Conclusion: Our study provides clinical evidence for the effectiveness of health care programs for pregnant women with GDM, and its results can be used to support the development of health care programs for GDM. More well-designed research is needed on GDM, especially studies that deal with emotional stress and apply a family-oriented approach.

저온 다결정 실리콘 박막 트랜지스터의 비정상적인 Hump 현상 분석 (Analysis of An Anomalous Hump Phenomenon in Low-temperature Poly-Si Thin Film Transistors)

  • 김유미;정광석;윤호진;양승동;이상율;이희덕;이가원
    • 한국전기전자재료학회논문지
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    • 제24권11호
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    • pp.900-904
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    • 2011
  • In this paper, we investigated an anomalous hump phenomenon under the positive bias stress in p-type LTPS TFTs. The devices with inferior electrical performance also show larger hump phenomenon. which can be explained by the sub-channel induced from trapped electrons under thinner gate oxide region. We can confirm that the devices with larger hump have larger interface trap density ($D_{it}$) and grain boundary trap density ($N_{trap}$) extracted by low-high frequency capacitance method and Levinson-Proano method, respectively. From the C-V with I-V transfer characteristics, the trapped electrons causing hump seem to be generated particularly from the S/D and gate overlapped region. Based on these analysis, the major cause of an anomalous hump phenomenon under the positive bias stress in p-type poly-Si TFTs is explained by the GIDL occurring in the S/D and gate overlapped region and the traps existing in the channel edge region where the gate oxide becomes thinner, which can be inferred by the fact that the magnitude of the hump is dependent on the average trap densities.

Degradation of High Performance Short Channel N-type Poly-Si TFT under the Electrical Bias Caused by Self-Heating

  • Choi, Sung-Hwan;Song, In-Hyuk;Shin, Hee-Sun;Park, Sang-Geun;Han, Min-Koo
    • 한국정보디스플레이학회:학술대회논문집
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    • 한국정보디스플레이학회 2007년도 7th International Meeting on Information Display 제7권2호
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    • pp.1301-1304
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    • 2007
  • We have investigated degradation of short channel n-type poly-Si TFTs with LDD under high gate and drain voltage stress due to self-heating. We have found that the threshold voltage of short channel TFT is shifted to negative direction on the selfheating stress, whereas the threshold voltage of long channel is moved to positive direction.

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박막 게이트 산화막의 열화에 의해 나타나는 MOSFET의 특성 변화 (The Effect of Degradation of Gate Oxide on the Electrical Parameters for Sub-Micron MOSFETS)

  • 이재성;이원규
    • 대한전자공학회:학술대회논문집
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    • 대한전자공학회 2003년도 하계종합학술대회 논문집 II
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    • pp.687-690
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    • 2003
  • Experimental results are presented for gate oxide degradation and its effect on device parameters under negative and positive bias stress conditions using NMOSFET's with 3 nm gate oxide. The degradation mechanisms are highly dependent on stress conditions. For negative gate voltage, both hole- and electron-trapping are found to dominate the reliability of gate oxide. However, with changing gate voltage polarity, the degradation becomes dominated by electron trapping. Statistical parameter variations as well as the "OFF" leakage current depend on those charge trapping. Our results therefore show that Si or O bond breakage by electron can be another origin of the investigated gate oxide degradation.gradation.

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Effects of parenting education programs for refugee and migrant parents: a systematic review and meta-analysis

  • Lee, In-Sook;Kim, Eunjung
    • Child Health Nursing Research
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    • 제28권1호
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    • pp.23-40
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    • 2022
  • Purpose: This systematic review and meta-analysis investigated the effects of parenting education programs (PEPs) for refugee and migrant parents. Methods: A systematic review was conducted according to PRISMA guidelines. Relevant studies published from 2000 to 2020 were identified through a systematic search of six electronic databases (PubMed, Embase, Cochrane Library, CINAHL, RISS, KMBASE). A meta-analysis of the studies was then undertaken. Results: Of the 14,996 published works identified, 23 studies satisfied the inclusion criteria, and 19 studies were analyzed to estimate the effect sizes (standardized mean differences) of the PEPs using random-effect models. PEPs were effective for parenting efficacy (effect size [ES]=1.40; 95% confidence interval [CI]: 1.14-1.66), positive parenting behaviors (ES=0.51; 95% CI: 0.30-0.73), parent-child relationships (ES=0.38; 95% CI: 0.22-0.53), and parenting stress (ES=0.64; 95% CI: 0.50-0.79). There were statistically significant differences in the effect sizes of PEPs that included mothers only (ES=0.93), included children under 7 years of age(ES=0.91), did not include child participation (0.77), continued for 19 or more sessions (ES=0.80), and were analyzed in quasi-experimental studies (ES=0.86). The overall effect of publication bias was robust. Conclusion: PEPs were found to be effective at improving parenting efficacy, positive parenting behaviors, parent-child relationships, and parenting stress.

CCD Image Sensor with Variable Reset Operation

  • Park, Sang-Sik;Uh, Hyung-Soo
    • JSTS:Journal of Semiconductor Technology and Science
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    • 제3권2호
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    • pp.83-88
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    • 2003
  • The reset operation of a CCD image sensor was improved using charge trapping of a MOS structure to realize a loe voltage driving. A DC bias generating circuit was added to the reset structure which sets reference voltage and holds the signal charge to be detected. The generated DC bias is added to the reset pulse to give an optimized voltage margin to the reset operation, and is controlled by adjustment of the threshold voltage of a MOS transistor in the circuit. By the pulse-type stress voltage applied to the gate, the electrons and holes were injected to the gate dielectrics, and the threshold voltage could be adjusted ranging from 0.2V to 5.5V, which is suitable for controlling the incomplete reset operation due to the process variation. The charges trapped in the silicon nitride lead to the positive and negative shift of the threshold voltage, and this phenomenon is explained by Poole-Frenkel conduction and Fowler-Nordheim conduction. A CCD image sensor with $492(H){\;}{\times}{\;}510(V)$ pixels adopting this structure showed complete reset operation with the driving voltage of 3.0V. The resolution chart taken with the image sensor shows no image flow to the illumination of 30 lux, even in the driving voltage of 3.0V.

Ecological Momentary Assessment Using Smartphone-Based Mobile Application for Affect and Stress Assessment

  • Yang, Yong Sook;Ryu, Gi Wook;Han, Insu;Oh, Seojin;Choi, Mona
    • Healthcare Informatics Research
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    • 제24권4호
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    • pp.381-386
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    • 2018
  • Objectives: This study aimed to describe the process of utilizing a mobile application for ecological momentary assessment (EMA) to collect data on stress and mood in daily life setting. Methods: A mobile application for the Android operating system was developed and installed with a set of questions regarding momentary mood and stress into a smartphone of a participant. The application sets alarms at semi-random intervals in 60-minute blocks, four times a day for 7 days. After obtaining all momentary affect and stress, the questions to assess the usability of the mobile EMA application were also administered. Results: The data were collected from 97 police officers working in Gyeonggi Province of South Korea. The mean completion rate was 60.0% ranging from 3.5% to 100%. The means of positive and negative affect were 18.34 of 28 and 19.09 of 63. The mean stress was 17.92 of 40. Participants responded that the mobile application correctly measured their affect ($4.34{\pm}0.83$) and stress ($4.48{\pm}0.62$) of 5-point Likert scale. Conclusions: Our study investigated the process of utilizing a mobile application to assess momentary affect and stress at repeated times. We found challenges regarding adherence to the research protocol, such as completion and delay of answering after alarm notification. Despite this inherent issue of adherence to the research protocol, the EMA still has advantages of reducing recall bias and assessing the actual moment of interest at multiple time points that improves ecological validity.

다양한 Passivation 물질에 따른 IGZO TFT Stability 개선 방법 (IGZO TFT Stability Improvement Based on Various Passivation Materials)

  • 김재민;박진수;윤건주;조재현;배상우;김진석;권기원;이윤정;이준신
    • 한국전기전자재료학회논문지
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    • 제33권1호
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    • pp.6-9
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    • 2020
  • Thin film transistors (TFTs) with large-area, high mobility, and high reliability are important factors for next-generation displays. In particular, thin transistors based on IGZO oxide semiconductors are being actively researched for this application. In this study, several methods for improving the reliability of a-IGZO TFTs by applying various materials on a passivation layer are investigated. In the literature, inorganic SiO2, TiO2, Al2O3, ZTSO, and organic CYTOP have been used for passivation. In the case of Al2O3, excellent stability is exhibited compared to the non-passivation TFT under the conditions of negative bias illumination stress (NBIS) for 3 wavelengths (R, G, B). When CYTOP passivation, SiO2 passivation, and non-passivation devices were compared under the same positive bias temperature stress (PBTS), the Vth shifts were 2.8 V, 3.3 V, and 4.5 V, respectively. The Vth shifts of TiO2 passivation and non-passivation devices under the same NBTS were -2.2 V and -3.8 V, respectively. It is expected that the presented results will form the basis for further research to improve the reliability of a-IGZO TFT.

Al Doped ZnO층 적용을 통한 ZnO 박막 트랜지스터의 전기적 특성과 안정성 개선 (Improvement of Electrical Performance and Stability in ZnO Channel TFTs with Al Doped ZnO Layer)

  • 엄기윤;정광석;윤호진;김유미;양승동;김진섭;이가원
    • 한국전기전자재료학회논문지
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    • 제28권5호
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    • pp.291-294
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    • 2015
  • Recently, ZnO based oxide TFTs used in the flexible and transparent display devices are widely studied. To apply to OLED display switching devices, electrical performance and stability are important issues. In this study, to improve these electrical properties, we fabricated TFTs having Al doped Zinc Oxide (AZO) layer inserted between the gate insulator and ZnO layer. The AZO and ZnO layers are deposited by Atomic layer deposition (ALD) method. I-V transfer characteristics and stability of the suggested devices are investigated under the positive gate bias condition while the channel defects are also analyzed by the photoluminescence spectrum. The TFTs with AZO layer show lower threshold voltage ($V_{th}$) and superior sub-threshold slop. In the case of $V_{th}$ shift after positive gate bias stress, the stability is also better than that of ZnO channel TFTs. This improvement is thought to be caused by the reduced defect density in AZO/ZnO stack devices, which can be confirmed by the photoluminescence spectrum analysis results where the defect related deep level emission of AZO is lower than that of ZnO layer.

Improvement on the Stability of Amorphous Indium Gallium Zinc Oxide Thin Film Transistors Using Amorphous Oxide Multilayer Source/Drain Electrodes

  • Lee, Sang Yeol
    • Transactions on Electrical and Electronic Materials
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    • 제17권3호
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    • pp.143-145
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    • 2016
  • In order to find suitable source and drain (S/D) electrodes for amorphous InGaZnO thin film transistors (a-IGZO TFTs), the specific contact resistance of interface between the channel layers and various S/D electrodes, such as Ti/Au, a-IZO and multilayer of a-IGZO/Ag/a-IGZO, was investigated using the transmission line model. The a-IGZO TFTs with a-IGZO/Ag/a-IGZO of S/D electrodes had good performance and low contact resistance due to the homo-junction with channel layer. The stability was measured with different electrodes by a positive bias stress test. The result shows the a-IGZO TFTs with a-IGZO/Ag/a-IGZO electrodes were more stable than other devices.