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51.
10MW高温气冷实验堆(HTR-10)是一座球床堆,由燃料元件装卸系统实现燃料元件的装卸和循环,且不需要停堆,为保证HTR-10的正常运行,燃料元件装卸系统必须安全,可靠,为此,必须对燃料元件装卸系统进行周密,细致的调试试验和验证,本文介绍了燃料元件装卸系统冷调试的主要调试项目,调试方法和调试结果。  相似文献   
52.
Field tests of the transmission performance of the ATSC DTV system have been conducted in Taiwan. The test results as well as comparisons against the NTSC system performance are reported and analyzed. From the measured results the reception characteristics of the DTV can be deduced and can provide guidelines for television stations to design the transmission system, schedule equipment deployment, plan service coverage areas, and improve the reception quality of the digital signal  相似文献   
53.
QRS feature extraction using linear prediction   总被引:10,自引:0,他引:10  
This communication proposes a method called linear prediction (a high performant technique in digital speech processing) for analyzing digital ECG signals. There are several significant properties indicating that ECG signals have an important feature in the residual error signal obtained after processing by Durbin's linear prediction algorithm. This communication also indicates that the prediction order need not be more than two for fast arrhythmia detection. The ECG signal classification puts an emphasis on the residual error signal. For each ECG's QRS complex, the feature for recognition is obtained from a nonlinear transformation which transforms every residual error signal to a set of three states pulse-code train relative to the original ECG signal. The pulse-code train has the advantage of easy implementation in digital hardware circuits to achieve automated ECG diagnosis. The algorithm performs very well in feature extraction in arrhythmia detection. Using this method, our studies indicate that the PVC (premature ventricular contraction) detection has at least a 92 percent sensitivity for MIT/BIH arrhythmia database.  相似文献   
54.
The Uniform Covering by Probabilistic Rejection (UCPR) algorithm was used, in conjunction with the Soil and Water Assessment Tool (SWAT) model, to identify P loads from point source and nonpoint source polluters in the upper Etowah River basin (UERB) in Georgia. The key findings of the research are as follows. The mean absolute error was preferred over the root mean square error as a search criterion for the UCPR algorithm when water quality observations are scarce. The undocumented P load from point sources in the UERB was consistently estimated as about 43 kg/d by the proposed method; but the method was not able to identify the broiler litter application rate to the poultry/beef operation pastures. Point sources (both documented and undocumented), poultry/beef operation pastures, and forests are the three major contributors of P. During 1992-1996, on average they accounted for 36.4, 31.7, and 17.2% of P load from the UERB, respectively.  相似文献   
55.
本文介绍了风力发电系统目前存在的技术方案,重点介绍了ABB用于双馈式风力发电系统的变频产品ACS800—67的特性,并对由其构建的发电机测试平台的案例进行了实验分析。  相似文献   
56.
多媒体业务对无线通信的带宽与品质提出了更高的要求,OFDM和MIMO由于满足了这一需求被越来越多的无线通信标准采用所为底层的调制和传输技术。频率同步问题是OFDM—MIMO物理层设计中正确解调的前提和基础,本文介绍了OFDM—MIMO的原理、特点和频率同步问题的研究现状。  相似文献   
57.
This paper describes how the use of inertia forces induced by the rotation of a working disk may be adopted to increase the fill rate of the flip-chip packaging process and thereby reduce the process cycle time. It is shown how the driving forces resulting from the inertia effect are determined by the Weber number. The constant and varying contact angle models are compared under a specified set of process conditions. The calculated flow behavior results indicate that the relationship between the contact angle, the average fluid velocity, the liquid-air interface position, and the filling time depends upon the Weber number. The constant and varying contact angle models are utilized in the analysis of a new processing method referred to as rotation-enhanced underfill packaging (REUP). The inertia effect induced by the angular motion of the working disk is shown to enhance the flow of the underfill encapsulant and to reduce the time of the underfill process. The present results confirm that the rotation of the working disk leads to an increased underfill capillary flow rate, which is beneficial in reducing the production cycle time of the flip-chip packaging process.  相似文献   
58.
We demonstrate the first programmable group-delay module based on polarization switching. With a unique binary tuning mechanism, the device can generate any differential group delay value from -45 to +45 ps with a resolution of 1.40 ps, or any true-time-delay value from 0 to 45 ps with a resolution of 0.7 ps. The delay varying speeds for both applications are under 1 ms and can be as fast as 0.1 ms. We evaluate both the dynamic and static performances of the device while paying special attention to its dynamic figures of merit for polarization-mode dispersion emulation and compensation applications. Our experiment shows that the device exhibits a negligible transient-effect induced power penalty (<0.2 dB) in a 10-Gb/s nonreturn-to-zero system.  相似文献   
59.
Stabilization of singularly perturbed fuzzy systems   总被引:6,自引:0,他引:6  
This paper presents some novel results for stabilizing singularly perturbed (SP) nonlinear systems with guaranteed control performance. By using Takagi-Sugeno fuzzy model, we construct the SP fuzzy (SPF) systems. The corresponding fuzzy slow and fast subsystems of the original SPF system are also obtained. Two fuzzy control designs are explored. In the first design method, we propose the composite fuzzy control to stabilize the SPF subsystem with H/sup /spl infin// control performance. Based on the Lyapunov stability theorem, the stability conditions are reduced to the linear matrix inequality (LMI) problem. The composite fuzzy control will stabilize the original SP nonlinear systems for all /spl epsiv//spl isin/(0,/spl epsiv//sup */) and the upper bound /spl epsiv//sup */ can be determined. For the second design method, we present a direct fuzzy control scheme to stabilize the SP nonlinear system with H/sup /spl infin// control performance. By utilizing the Lyapunov stability theorem, the direct fuzzy control can guarantee the stability of the original SP nonlinear systems for a given interval /spl epsiv//spl isin/[/spl epsiv/_,/spl epsiv/~]. The stability conditions are also expressed in the LMIs. Two SP nonlinear systems are adopted to demonstrate the feasibility and effectiveness of the proposed control schemes.  相似文献   
60.
对当前隔震系统做了简单介绍 ,介绍了基础隔震的技术和施工方法等。讨论在住宅结构中推广隔震技术的方法 ,对各种类型的住宅结构做经济评价 ,讨论推广的可能性和难点。  相似文献   
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