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51.
Degradation Behaviors of Metal-Induced Laterally Crystallized n-Type Polycrystalline Silicon Thin-Film Transistors Under DC Bias Stresses 总被引:1,自引:0,他引:1
Min Xue Mingxiang Wang Zhen Zhu Dongli Zhang Man Wong 《Electron Devices, IEEE Transactions on》2007,54(2):225-232
Device degradation behaviors of typical-sized n-type metal-induced laterally crystallized polycrystalline silicon thin-film transistors were investigated in detail under two kinds of dc bias stresses: hot-carrier (HC) stress and self-heating (SH) stress. Under HC stress, device degradation is the consequence of HC induced defect generation locally at the drain side. Under a unified model that postulates, the establishment of a potential barrier at the drain side due to carrier transport near trap states, device degradation behavior such as asymmetric on current recovery and threshold voltage degradation can be understood. Under SH stress, a general degradation in subthreshold characteristic was observed. Device degradation is the consequence of deep state generation along the entire channel. Device degradation behaviors were compared in low Vd-stress and in high Vd-stress condition. Defect generation distribution along the channel appears to be different in two cases. In both cases of SH degradation, asymmetric on current recovery was observed. This observation, when in low Vd-stress condition, is tentatively explained by dehydrogenation (hydrogenation) effect at the drain (source) side during stress 相似文献
52.
Application of model predictive control strategy based on fuzzy identification to an SP-100 space reactor 总被引:1,自引:0,他引:1
In this work, a model predictive control method combined with fuzzy identification, is applied to the design of the thermoelectric (TE) power control in the SP-100 space reactor. The future TE power is predicted by using the fuzzy model identified by a subtractive clustering method of a fast and robust algorithm. The objectives of the proposed fuzzy model predictive controller are to minimize both the difference between the predicted TE power and the desired power, and the variation of control drum angle that adjusts the control reactivity. Also, the objectives are subject to maximum and minimum control drum angle and maximum drum angle variation speed. The genetic algorithm that is effective in accomplishing multiple objectives is used to optimize the fuzzy model predictive controller. A lumped parameter simulation model of the SP-100 nuclear space reactor is used to verify the proposed controller. The results of numerical simulations to check the performance of the proposed controller show that the TE generator power level controlled by the proposed controller could track the target power level effectively, satisfying all control constraints. 相似文献
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54.
为使北京谱仪端盖族射计数器更好地工作在自猝灭流光SQS模式下,提高其能量分辨以及线性等指标,用Ar,CO2,Lsobutane三元工作气体对探测器的工作性能进行了仔细研究,找出了一适合于主雇地数器的工作气体,此外,还研究了异丁的纯度对探测器性能的影响。 相似文献
55.
Ion V. Nicolaescu Gabriel Tardos Richard E. Riman 《Journal of the American Ceramic Society》1994,77(9):2265-2272
A thermogravimetric method for the measurement of carbon, nitrogen, and oxygen in aluminum nitride is described. Since carbon oxidation occurs at lower temperatures than the oxidation of the aluminum compounds, thermogravimetric analyses in the respective temperature regimes can yield measurement of the oxygen, nitrogen, and carbon content. Thermogravimetric analyses were performed on mixtures of aluminum nitride and carbon with various concentrations in order to evaluate the accuracy of this method. The results were compared with those obtained by the hot gas extraction method. Errors produced by overlapping of the temperature ranges of the reactions were evaluated and experimental conditions were optimized to minimize error. This method can produce reliable results at elemental concentrations higher than a few percent. The absolute errors of the C/AI, N/Al, and O/Al atomic ratios were less then 0.02. The detection limit was evaluated to 0.2 wt% of each element. The applicability of the method to the study of the kinetics of the nitridation reaction was demonstrated. 相似文献
56.
57.
Suk Lee Kyung Chang Lee Man Hyung Lee Harashima F. 《Industrial Electronics, IEEE Transactions on》2002,49(3):693-701
This paper focuses on a method to integrate mobile devices such as a mobile robot, automated guided vehicle, and unmanned container transporter to form an automated material handling system. In this paper, the stationary devices are connected via a Profibus network while the mobile devices are communicating via an IEEE 802.11 wireless LAN. In order to integrate these two networks, a protocol converter is developed on a PC platform that runs two interacting processes with shared internal buffers. The protocol converter performs a role of translator between two different protocols by converting the format of a data frame. In addition to this basic conversion function, the protocol converter has a virtual polling algorithm to reduce the uncertainty involved in accessing the wireless network. Finally, the integrated network. of Profibus and IEEE 802.11 is experimentally evaluated for its data latency and throughput, which shows the feasibility of the Profibus-IEEE 802.11 network for industrial applications involving mobile devices 相似文献
58.
59.
Different types of signal coupling in the visual cortex related to neural mechanisms of associative Processing and perception 总被引:1,自引:0,他引:1
Eckhorn R. Gail A.M. Bruns A. Gabriel A. Al-Shaikhli B. Saam M. 《Neural Networks, IEEE Transactions on》2004,15(5):1039-1052
The hypothesis of object representation by synchronization in the visual cortex has been supported by our recent experiments in monkeys. They demonstrated local synchrony among /spl gamma/ activities (30-90 Hz) and their perceptual modulation, according to the rules of figure-ground segregation. However, /spl gamma/-synchrony in primary visual cortex is restricted to few mm, challenging the synchronization hypothesis for larger cortical object representations. The restriction is due to randomly changing phase relations among locally synchronized patches which, however, form continuous waves of /spl gamma/-activity, traveling across object representations. The phase continuity of these waves may support coding of object continuity. Interactions across still larger distances, measured among cortical areas in human data, involve amplitude envelopes of /spl gamma/ signals. Based on models with spiking neurons we discuss potentially underlying mechanisms. Most important for /spl gamma/ synchronization are local facilitatory connections with distance-dependent delays. They also explain the occurrence of /spl gamma/ waves and the restriction of /spl gamma/-synchrony. Fast local feedback inhibition generates /spl gamma/ oscillations and supports local synchrony, while slow shunting inhibitory feedback supports figure-ground segregation. Finally, dispersion in inter-areal far projections destroys coherence of /spl gamma/ signals, but preserves their amplitude modulations. In conclusion, we propose that the hypothesis of associative processing by /spl gamma/ synchronization be extended to more general forms of signal coupling. 相似文献
60.