• Title/Summary/Keyword: High mobility

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Connecting the three Dimensions of Urban Transportation

  • Cesarz, Michael
    • International Journal of High-Rise Buildings
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    • v.9 no.1
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    • pp.81-85
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    • 2020
  • Currently, urban mobility is rather two-dimensional: Connections between transportation solutions like elevators, escalators, moving walks, and metro stations are static. In the future, urban mobility will require a holistic view: Seamless transportation, enabled by innovative IoT technology, is a necessity. A dialogue between the city, its buildings and transportation systems, considering the specific needs and preferences of each and every citizen, must be adopted. Travelling through the city will become a lot more individualized, interactive and customized to specific requirements.

Extraction of empirical formulas for electron and hole mobility in $In_{0.53}(Al_xGa_{1-x})_{0.47}As$ ($In_{0.53}(Al_xGa_{1-x})_{0.47}As$의 전자와 정공 이동도의 실험식 추출)

  • 이경락;황성범;송정근
    • Electrical & Electronic Materials
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    • v.9 no.6
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    • pp.564-571
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    • 1996
  • We calculated the drift-velocities of electrons and holes of I $n_{0.53}$(A $l_{x}$G $a_{1-x}$ )$_{0.47}$As, which is used for semiconductor materials of high performance HBTs, along with the various doping concentrations and Al mole fractions as well as the electric fields by Monte Carlo experiment. Especially, for the valence bands the accuracy of hole-drift-velocity was improved in the consideration of intervalley scattering due to the inelastic scattering of acoustic phonon. From the results the empirical formulas of the low- and high field mobility of electrons and holes were extracted by using nonlinear least square fitting method. The accuracy of the formulas was proved by comparing the formula of low-field electron mobility as well as drift-velocity of I $n_{0.53}$ G $a_{0.47}$As and of low-field hole mobility of GaAs with the measured values, where the error was below 10%. For the high-field mobilities of electron and hole the results calculated by the formulas were very well matched with the MC experimental results except at the narrow field range where the electrons produced the velocity overshoot and the corresponding error was about 30%.0%. 30%.0%.

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Effect of Sputtering Working Pressure on the Optical and Electrical Properties of InZnO Thin-Film Transistors (스퍼터링 공정 압력이 InZnO 박막트랜지스터의 광학 및 전기적 특성에 미치는 영향)

  • Park, Ji-Min;Kim, Hyoung-Do;Jang, Seong Cheol;Kim, Hyun-Suk
    • Korean Journal of Materials Research
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    • v.30 no.4
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    • pp.211-216
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    • 2020
  • Amorphous In-Ga-Zn-O (a-IGZO) thin film transistors, because of their relatively low mobility, have limits in attempts to fulfill high-end specifications for display backplanes. In-Zn-O (IZO) is a promising semiconductor material for high mobility device applications with excellent transparency to visible light region and low temperature process capability. In this paper, the effects of working pressure on the physical and electrical properties of IZO films and thin film transistors are investigated. The working pressure is modulated from 2 mTorr to 5 mTorr, whereas the other process conditions are fixed. As the working pressure increases, the extracted optical band gap of IZO films gradually decreases. Absorption coefficient spectra indicate that subgap states increase at high working pressure. Furthermore, IZO film fabricated at low working pressure shows smoother surface morphology. As a result, IZO thin film transistors with optimum conditions exhibit excellent switching characteristics with high mobility (≥ 30㎠/Vs) and large on/off ratio.

Geographic Mobility and Related Factors among Newly Graduated Nurses (신입간호사의 지역간 이동 양상과 영향요인)

  • Yoon, Hyo-Jeong;Cho, Sung-Hyun
    • The Journal of Korean Academic Society of Nursing Education
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    • v.23 no.3
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    • pp.353-362
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    • 2017
  • Purpose: This study aimed to analyze the mobility of newly graduated nurses from regions where their nursing schools were located to regions where they took up their first jobs, and to identify factors influencing nurses' mobility. Methods: Data from the Graduates Occupational Mobility Survey, collected annually from 2010 to 2014 by the Korea Employment Information Service, were analyzed. The sample consisted of 1,488 graduates and 1,229 nurses who were employed on a full-time basis in hospitals. Multiple logistic regression analysis was conducted to identify factors associated with geographic mobility. Results: Among the nurses working in hospitals, 69.2% had their first jobs in their nursing school regions and 11.3% in their high school regions. Fifty-two percent of the nurses worked in the capital region; 47.2% thereof had moved from a non-capital region. Nurses were more likely to work in their nursing school region when they were female, were older, graduated from a high school located in their nursing school region, graduated from a college (vs. university), had a lower nursing school performance, and expected lower monthly wage, compared with those who left their nursing school region. Conclusion: Education and remuneration policies are required to reduce geographical mobility to the capital region.

Substrate Doping Concentration Dependence of Electron Mobility Enhancement in Uniaxial Strained (110)/<110> nMOSFETs

  • Sun, Wookyung;Choi, Sujin;Shin, Hyungsoon
    • JSTS:Journal of Semiconductor Technology and Science
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    • v.14 no.5
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    • pp.518-524
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    • 2014
  • The substrate doping concentration dependence of strain-enhanced electron mobility in (110)/<110> nMOSFETs is investigated by using a self-consistent Schr$\ddot{o}$dinger-Poisson solver. The electron mobility model includes Coulomb, phonon, and surface roughness scattering. The calculated results show that, in contrast to (100)/<110> case, the longitudinal tensile strain-induced electron mobility enhancement on the (110)/<110> can be increased at high substrate doping concentration.

Theoretical Study of Electron Mobility in Double-Gate Field Effect Transistors with Multilayer (strained-)Si/SiGe Channel

  • Walczak, Jakub;Majkusiak, Bogdan
    • JSTS:Journal of Semiconductor Technology and Science
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    • v.8 no.3
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    • pp.264-275
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    • 2008
  • Electron mobility has been investigated theoretically in undoped double-gate (DG) MOSFETs of different channel architectures: a relaxed-Si DG SOI, a strained-Si (sSi) DG SSOI (strained-Si-on-insulator, containing no SiGe layer), and a strained-Si DG SGOI (strained-Si-on-SiGe-on-insulator, containing a SiGe layer) at 300K. Electron mobility in the DG SSOI device exhibits high enhancement relative to the DG SOI. In the DG SGOI devices the mobility is strongly suppressed by the confinement of electrons in much narrower strained-Si layers, as well as by the alloy scattering within the SiGe layer. As a consequence, in the DG SGOI devices with thinnest strained-Si layers the electron mobility may drop below the level of the relaxed DG SOI and the mobility enhancement expected from the strained-Si devices may be lost.

Performance Evaluation of Hybrid Distributed Mobility Management (하이브리드 분산 이동성 관리 방식의 성능 평가)

  • Wie, Sunghong;Jang, Jaeshin
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.21 no.10
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    • pp.1862-1872
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    • 2017
  • To overcome the limitations of the current Central Mobility Management (CMM) protocols, IETF has been discussing about the Distributed Mobility Management (DMM) protocols that the centralized mobility functions of Home Agents (HA) are distributed to network edges closer to mobile users. The DMM protocol has some advantages of low-cost traffic delivery and high scalability. However, it faces several problems such as a high signaling cost and a complex address management. Especially, users moving at a high speed and with long-live sessions can make these problems worse. To reduce the high signaling cost for long-live sessions, we propose a novel hybrid DMM protocol allocating different mobility anchors according to the session durations. In this paper, we analyze the performance of the proposed hybrid DMM protocol and show superior performance with respect to the signaling cost.

Immediate Effects of High-Frequency Diathermy on Neck, Shoulder Alignment, Pain and Function in Adults with Forward Head Posture (고주파심부투열 치료가 앞쪽머리자세를 가진 성인의 자세정렬, 통증 그리고 기능에 미치는 즉각적인 효과)

  • Young-Joo Cha;Kyoung-Tae Kim
    • Journal of The Korean Society of Integrative Medicine
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    • v.12 no.3
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    • pp.143-153
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    • 2024
  • Purpose : Forward head posture (FHP), characterized by the anterior positioning of the head relative to the spine, is a common postural deviation that can lead to neck pain, reduced mobility, and muscle imbalances. Recently, high-frequency deep heat therapy (HFDT) has been gaining attention for the intervention of FHP. This research aims to investigate the efficacy of HFDT in comparison to instrument assisted soft-tissue mobilization (IASTM) for treating FHP among 30 young adults. Methods : Participants were randomly assigned to either the HFDT or IASTM group. The study focused on examining changes in neck joint mobility, pain thresholds, rounded shoulder distance, lower trapezius muscle strength, and neck dysfunction. Measurements were taken before and after the interventions. Paired t-tests were used for within-group analyses, and independent t-tests were employed for between-group comparisons. The statistical significance level α was set to .05. Results : Statistically significant improvements were observed across all measured parameters in both groups (p<.05). The HFDT group showed significantly greater enhancements in neck joint mobility, pain thresholds, rounded shoulder distance, lower trapezius muscle strength, and neck dysfunction parameters. Specifically, HFDT was more effective than IASTM in improving neck joint mobility, right upper trapezius pain threshold, left rounded shoulder distance, and right lower trapezius strength. The only exceptions were neck flexion range of motion, left upper trapezius pain threshold, right rounded shoulder distance, and left lower trapezius strength, where no significant differences were found between the groups. Conclusion : The findings suggest that HFDT, by combining the benefits of high-frequency therapy and manual therapy, effectively alleviates upper trapezius muscle pain and tension, enhances neck mobility, and strengthens lower trapezius muscles. Thus, HFDT could be considered a valuable intervention for clinicians aiming to address FHP and associated musculoskeletal problems.

Mobility Determination of Thin Film a-Si:H and poly-Si

  • Jung, S.M.;Choi, Y.S.;Yi, J.S.
    • Journal of Sensor Science and Technology
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    • v.6 no.6
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    • pp.483-490
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    • 1997
  • Thin film Si has been used in sensors, radiation detectors, and solar cells. The carrier mobility of thin film Si influences the device behavior through its frequency response or time response. Since poly-Si shows the higher mobility value, a-Si:H films on Mo substrate were subjected to various crystallization treatments. Consequently, we need to find an appropriate method in mobility measurement before and after the anneal treatment. This paper investigates the carrier mobility improvement with anneal treatments and summarizes the mobility measurement methods of the a-Si:H and poly-Si film. Various techniques were investigated for the mobility determination such as Hall mobility, HS, TOF, SCLC, TFT, and TCO method. We learned that TFT and TCO method are suitable for the mobility determination of a-Si:H and poly-Si film. The measured mobility was improved by $2{\sim}3$ orders after high temperature anneal above $700^{\circ}C$ and grain boundary passivation using an RF plasma rehydrogenation.

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Control of Weighted Mobility Ratio to Enhance the Performance of Bi-Te-based Thermoelectric Materials (Bi-Te계 열전소재 성능 증대를 위한 Weighted Mobility Ratio 제어)

  • Kim, Min Young;Kim, Hyun-Sik;Lee, Kyu Hyoung
    • Journal of the Microelectronics and Packaging Society
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    • v.28 no.4
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    • pp.103-107
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    • 2021
  • Temperature dependences of electronic and thermal transport properties of narrow band gap thermoelectric materials are dependent on the transport behavior of minority carriers as well as majority carriers. Thus, weighted mobility ratio, which is defined the ratio of weighted mobility for majority carriers to that for minority carriers, must be one of the important parameters to enhance the performance of thermoelectric materials. Herein, we provided a practical guide for the development of high-performance Bi-Te-based thermoelectric materials based on the weighted mobility ratio control by considering theoretical backgrounds related to the electronic transport phenomena in semiconductors.