• Title/Summary/Keyword: lateral current

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Suppressing Lateral Conduction Loss of Thin-film Cathode by Inserting a Denser Bridging Layer

  • Park, Jung Hoon;Lee, Seung Hwan;Kim, Hyoungchul;Yoon, Kyung Joong;Lee, Jong-Ho;Han, Seung Min;Son, Ji-Won
    • Journal of the Korean Ceramic Society
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    • v.52 no.5
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    • pp.304-307
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    • 2015
  • To reduce the lateral conduction loss of thin-film-processed cathodes, the microstructure of the thin-film cathode is engineered to contain a denser bridging layer in the middle. By doing so, the characteristic crack-like pores that separate the cathode domains in thin-film-processed cathodes and hamper lateral conduction are better connected and, as a result, the sheet resistance of the cathode is effectively reduced by a factor of 5. This induces suppression of the lateral conduction loss and expansion of the effective current collecting area; the cell performance is improved by more than 30%.

Modified Equivalent Frame Models for Flat Plate slabs Under Lateral Load (수평하중을 받는 플랫 플레이트 슬래브 해석을 위한 수정된 등가골조모델)

  • Park Young Mi;Cho Kyung Hyun;Han Sang Whan;Lee Li Hyung
    • Proceedings of the Korea Concrete Institute Conference
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    • 2004.05a
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    • pp.272-275
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    • 2004
  • This study is to propose a modified equivalent frame method under lateral loading. ACI 318-02 allows the equivalent frame method to conduct slab analysis subjected to lateral loads. However, current method can not predict the behavior of the slabs particularly under lateral loading because the equivalent frame method in the ACI 318 has been developed against gravity loads. This study provides more precise model for the analysis of the flat plate slabs under lateral loading. The model reflect the force transfer mechanism of slabs, column and torsional member more accurately than the existing model. The accuracy of this model is verified by compared with finite element method analysis results.

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Lateral Electric Field Model and Degradation Mechanism of surface-Channel PMOSFET's (SC PMOSFET의 수평 전개 모델과 노쇠화 메카니즘)

  • 양광선;박종태;김봉렬
    • Journal of the Korean Institute of Telematics and Electronics A
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    • v.31A no.1
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    • pp.54-60
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    • 1994
  • In this paper, we present the analytical models for the change of the lateral electric field distribution and the velocity saturation region length with the electron trapping of stressed SC-PMOSFET in the saturation region. To derive the hot-electron-induced lateral electric field of stressed SC-PMOSFET. Ko's pseudo two dimensional box model in the saturation region which illustrates the analysis of the velocity saturation region is modified under the condition of electron trapping in the oxide near the drain region. From the results, we have the following lateral electric field in the y-direction, that is, E(y) ES1satT.cosh(y/l) qNS1tT.sinh(y/l)/lCox. It is shown that the trapped electrons influence the field in the drain region. decreasing the lateral electric field. Calculated velocity saturaion length increases with the trapped electrons. increasing the drain current of stressed SCPMOSFET. This results well explain the HEIP phenomenon of PMOSFET's.

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Lateral Far-field Characteristics of Narrow-width 850 nm High Power GaAs/AlGaAs Laser Diodes

  • Yang, Jung-Tack;Kwak, Jung-Geun;Choi, An-Sik;Kim, Tae-Kyung;Choi, Woo-Young
    • Current Optics and Photonics
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    • v.6 no.2
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    • pp.191-195
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    • 2022
  • We investigate the lateral far-field pattern characteristics, including divergence angle change and far-field pattern analysis as output power increases, of narrow-emitter-width 850 nm GaAs/AlGaAs laser diodes (LDs). Each LD has a cavity of 1200 and 1500 ㎛ and narrow emitter width of 2.4 ㎛ for the top and 4.6 ㎛ for the bottom. The threshold currents are 35 and 40 mA, and L-I kinks appear at power levels of 326 and 403 mW, respectively. The divergence angle tends to increase due to the occurrence of first-order lateral mode and the thermal lensing effect. But with the L-I kink, the divergence angle decreases and the far-field pattern becomes asymmetric. This is due to coherent superposition between the fundamental and the first-order lateral mode. We provide detailed explanations for these observations based on high-power laser diode simulation results.

28 nm MOSFET Design for Low Standby Power Applications (저전력 응용을 위한 28 nm 금속 게이트/high-k MOSFET 디자인)

  • Lim, To-Woo;Jang, Jun-Yong;Kim, Young-Min
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.57 no.2
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    • pp.235-238
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    • 2008
  • This paper explores 28 nm MOSFET design for LSTP(Low Standby Power) applications using TCAD(Technology Computer Aided Design) simulation. Simulated results show that the leakage current of the MOSFET is increasingly dominated by GIDL(Gate Induced Drain Leakage) instead of a subthreshold leakage as the Source/Drain extension doping increases. The GIDL current can be reduced by grading lateral abruptness of the drain at the expense of a higher Source/Drain series resistance. For 28 nm MOSFET suggested in ITRS, we have shown Source/Drain design becomes even more critical to meet both leakage current and performance requirement.

Study on Lateral Flow Distribution and Momentum Analysis at Flood season and Neap tide of the Seokmo Channel in the Han River estuary (소조기 홍수시 한강하구 석모수로에서의 횡 방향 2차 흐름 및 운동량 분석)

  • Choi, Nak Yong;Woo, Seung-Buhm
    • Journal of Korean Society of Coastal and Ocean Engineers
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    • v.24 no.6
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    • pp.390-399
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    • 2012
  • This research observed the cross section current of 7 survey lines in Seokmo Channel of Gyeonggi bay with a lot of freshwater inflow and S-shaped for 13 hours during flood season and neap tide. We indicated the distribution of the current velocity by comprehending the speed and direction of the current velocity of each line during maximum flood, ebb tide and observed the distribution of salinity. Moreover, in order to understand what lateral momentum causes the lateral flow in each survey line, we practiced the momentum analysis through the observation data. As a result, the lateral baroclinic pressure gradient force and vertical friction of the Seokmo channel during neap tide were the strongest, and this is why the flow by the distribution of salinity and stratification most often occurs. In north of the Seokmo channel, where have wide intertidal and a lot of freshwater inflow, the secondary circulation is caused by balance of lateral baroclinic pressure gradient force and other forces, and the vertical friction was strong in the lines with small depth. On the other hand, in the southern part of the Seokmo channel where the water is deep and the waterway is curved, the advective acceleration and centrifugal force become stronger by the geographical causes during ebb and the influence of fresh water. Therefore, the lateral flow in the Seokmo channel was caused by the distribution of the momentum that differs by location, depth, curve, etc.

Effects of Abdominal Draw-In Maneuver Combined with Transcranial Direct Current Stimulation on Balance Ability and Trunk Function in Chronic Stroke Patients (경두개 직류 전기 자극과 병행한 배 드로우인 방법이 만성 뇌졸중 환자의 균형 능력과 몸통 기능에 미치는 영향)

  • Yang-Jin Lee
    • Journal of The Korean Society of Integrative Medicine
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    • v.11 no.2
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    • pp.101-108
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    • 2023
  • Purpose : To investigate effects of transcranial directed current stimulus (tDCS) combined with abdominal draw-in maneuver (ADIM) on balance ability and trunk impairment scale of chronic stroke patients. Methods : Twenty-six chronic stroke patients were recruited and twenty-four participated after excluding two patients who met the exclusion criteria. After screening tests, they were randomized through excel program into an experimental group (n = 12) to apply a tDCS combined with ADIM and a control group (n = 12) to apply a sham tDCS with ADIM. The intervention lasted three times a week for six weeks. To compare tDCS intervention effects, trunk impairment scale and balance ability were measured. Comparisons between experimental and control groups were statistically processed using an independent t-test and comparisons within groups were statistically processed using a paired t-test. Results : The experimental group showed significant increases of pre- and post-intervention medial lateral velocity, anterior posterior velocity and area of balance ability, and trunk impairment scale (p<.05). The control group showed significant increases in pre- and post-intervention medial lateral velocity of balance ability and trunk impairment scale (p< .05). The experimental group showed significant increases of medial lateral velocity of balance ability and trunk impairment scale compared to the control group (p<.05). Conclusion : Results of this study suggest that tDCS combined with ADIM for chronic stroke patients can be effective in improving medial lateral velocity of balance ability and trunk impairment scale. Thus, tDCS can be used as an effective treatment protocol for trunk rehabilitation of chronic stroke patients.

A Strategy for Homogeneous Current Distribution in Direct Methanol Fuel Cells through Spatial Variation of Catalyst Loading

  • Park, Sang-Min;Kim, Sang-Kyung;Peck, Dong-Hyun;Jung, Doo-Hwan
    • Journal of Electrochemical Science and Technology
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    • v.8 no.4
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    • pp.331-337
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    • 2017
  • A simple strategy is proposed herein for attaining uniform current distribution in direct methanol fuel cells by varying the catalyst loading over the electrode. In order to use the same total catalyst amount for a serpentine flow field, three spatial variation types of catalyst loading were selected: enhancing the cathode catalyst loading (i) near the cathode outlet, (ii) near the cathode inlet, and (iii) near the lateral areas. These variations in catalyst loading are shown to improve the homogeneity of the current distribution, particularly at lower currents and lower air-flow rates. Among these three variations, increased loading near the lateral areas was shown to contribute most to achieving a homogenous current distribution. The mechanism underlying each catalyst loading variation method is different; very high catalyst-loading is shown to decrease the homogeneity of the distribution, which may be caused by water management in the thick catalyst layer thereof.

Analysis of Failure Behavior of Pile Embedded in Liquefiable Soil Deposits considering Buckling Instability (좌굴을 고려한 액상화 지반에 근입된 말뚝의 파괴거동 분석)

  • Han, Jin-Tae;Cho, Chong-Suck;Hwang, Jae-Ik;Kim, Myoung-Mo
    • Proceedings of the Earthquake Engineering Society of Korea Conference
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    • 2006.03a
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    • pp.105-112
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    • 2006
  • Liquefaction-induced lateral spreading has been the most extensive damage to pile foundations during earthquakes. However, a case of pile failure was reported despite the fact that a large margin of safety factor was employed in their design. This means that the current seismic design method of pile is not agreeable with the actual failure mechanism of pile. Newly proposed failure mechanism of pile is a pile failure based on buckling instability. In this study, failure behavior of pile embedded in liquefied soil deposits was analyzed considering lateral spreading and buckling instability performing 1g shaking table test. As a result, it can be concluded that the pile subjected to excessive axial loads ($near\;P_{cr}$) can fail by buckling instability during liquefaction. When lateral spreading took place in sloping grounds, lateral spreading increased lateral deflection of pile and reduced the buckling load, promoting more rapid collapse. In addition, buckling shape of pile was observed. In the ease of pile buckling, hinge formed at the middle of the pile, not at the bottom. And in sloping grounds, location of hinge got loiter compared with level ground because of the effects of lateral spreading.

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Lateral vibration control of a low-speed maglev vehicle in cross winds

  • Yau, J.D.
    • Wind and Structures
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    • v.15 no.3
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    • pp.263-283
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    • 2012
  • This paper presents a framework of nonlinear dynamic analysis of a low-speed moving maglev (magnetically levitated) vehicle subjected to cross winds and controlled using a clipped-LQR actuator with time delay compensation. A four degrees-of-freedom (4-DOFs) maglev-vehicle equipped with an onboard PID (Proportional-Integral-Derivative) controller traveling over guideway girders was developed to regulate the electric current and control voltage. With this maglev-vehicle/guideway model, dynamic interaction analysis of a low-speed maglev vehicle with guideway girders was conducted using an iterative approach. Considering the time-delay issue of unsynchronized tuning forces in control process, a clipped-LQR actuator with time-delay compensation is developed to improve control effectiveness of lateral vibration of the running maglev vehicle in cross winds. Numerical simulations demonstrate that although the lateral response of the maglev vehicle moving in cross winds would be amplified significantly, the present clipped-LQR controller exhibits its control performance in suppressing the lateral vibration of the vehicle.