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991.
In this paper, a piezoelectric diaphragm-based immunoassay chip was developed to simultaneously detect anti-Hepatitis B virus (HBV) and anti-alpha-fetoprotein (AFP). The chip was fabricated by micro-machining technology and consists of eight individual circular sensors with a diameter of 800 μm. Hepatitis B surface antigen (HBsAg), Hepatitis C core antigen (HBcAg) and AFP as the probe molecules were immobilized on different sensing spots on the chip. A solution containing anti-HBsAg and anti-AFP was applied into the reaction chambers in all sensors of the chip, and significant frequency shifts were only observed in the sensors with HBsAg and AFP for immunoassay detection. The fluorescence image further confirmed the successful detection of anti-HBsAg and anti-AFP. The total assay time was less than 2 h. The frequency shift-based calibration curves show a detection limit of 0.1 ng/ml and a dynamic detection range of 0.1-10,000 ng/ml for both anti-HBsAg and anti-AFP, respectively, thus demonstrating that the developed piezoelectric immunoassay chip has potential applications for rapid, specific, sensitive, and multiple detections of HBV.  相似文献   
992.
Flywheel energy storage has been widely used to improve the ground electric power quality. This paper designed a flywheel energy storage device to improve ship electric propulsion system power grid quality. The practical mathematical models of flywheel energy storage and ship electric propulsion system were established. Simulation research on the effect of ship electric propulsion system power quality, made by flywheel energy storage, was completed by using the software Matlab/simulink. We have done a lot of simulation experiments on sudden load of ship integrated electric propulsion system, one system is with flywheel energy storage, another one is not with. Comparing with these simulation results, we can see that the flywheel energy storage designed in this paper has improved ship electric propulsion system network power quality as well as increases the reliability of the ship power grid. The conclusions can provide a theoretical guidance for the design of flywheel energy storage applied in ship integrated electric propulsion system.  相似文献   
993.
In recent years, some fuzzy rule interpolation methods have been presented for sparse fuzzy rule-based systems based on interval type-2 fuzzy sets. However, the existing methods have the drawbacks that they cannot guarantee the convexity of the fuzzy interpolated result and may generate the same fuzzy interpolated results with respect to different observations. Moreover, they also cannot deal with fuzzy rule interpolation with bell-shaped interval type-2 fuzzy sets. In this paper, we present a new method for fuzzy rule interpolation for sparse fuzzy rule-based systems based on the ratio of fuzziness of interval type-2 fuzzy sets. The proposed method can overcome the drawbacks of the existing methods. First, it calculates the weights of the closest fuzzy rules with respect to the observation to obtain an intermediate consequence fuzzy set. Then, it uses the ratio of fuzziness of interval type-2 fuzzy sets to infer the fuzzy interpolated result based on the intermediate consequence fuzzy set. We also use some examples to compare the fuzzy interpolated results of the proposed method with the results by the existing methods. The experimental results show that the proposed fuzzy rule interpolation method gets more reasonable results than the existing methods.  相似文献   
994.
This study applies energy method to derive the system modeling of a triaxial microaccelerometer that consists of a quadri-beam suspension, a seismic mass, and displacement transducers using piezoelectric thin films. Two suspension beams support both ends of the seismic mass, which is fabricated by anisotropic etching of silicon. An out-of-plane acceleration will result in a symmetric bend, and in-plane accelerations will produce asymmetric bend and torsion of the suspension beams. Two piezoelectric thin-film transducers are arranged at both ends of each suspension beam. Eight transducers in total are interconnected such that triaxial accelerations can be measured selectively. The structure stiffness of the suspension beams considers both the silicon beams and piezoelectric films by the use of the laminated beam theory. Therefore, the analytical model is applicable to the accelerometers with thick piezoelectric films. The model is based on the anisotropic material properties of Silicon and PZT and Euler’s beam equation with the assumptions that smaller strains and stresses are negligible. The analytical results of the resonant frequencies and sensor sensitivities to triaxial accelerations are presented and confirmed by finite element analysis.  相似文献   
995.
Wei-Lun Chang 《Knowledge》2011,24(8):1181-1186
In the past, companies changed their focus from product-oriented within marketing to demand-oriented within quality improvement. Today, they emphasize customer service, customer loyalty, and customer profitability. The significance of customer-centric services has become critical and essential. However, certain research which investigates the effect of customer lifetime value focuses only on lifetime values of existing customers. This study devises a novel model to predict customers’ prospect value. In the proposed model, we utilize the concept of finance which stands in the current status and predicts future value based on historical data. The simulated results reveal that, in a long-term simulation, customer prospect value rises when reach rate increases. Decreasing reach rate and costs result in high customer prospect value; however, the value of customer prospect value decreases in a long-term simulation. The new model complements the existing customer lifetime value model from a different perspective and provides clues to customer value for future researches.  相似文献   
996.
给出了一种由方向盘转角及力矩传感器、16位∑-△型数模转换器、单片机和CAN总线芯片所组成的方向盘转角及转向力矩采集方案.阐述了A/D转换、转角及力矩值计算、CAN通讯的实现以及上位机采集软件的编写等重要过程的实现方法,在此基础上实现了对方向盘转角及转向力矩的数据采集,并进行了实际车载环境使用.应用结果表明,该系统测试...  相似文献   
997.
Passwords are used in the vast majority of computer and communication systems for authentication. The greater security and memorability of graphical passwords make them a possible alternative to traditional textual passwords. In this paper we propose a new graphical password scheme called YAGP, which is an extension of the Draw-A-Secret (DAS) scheme. The main difference between YAGP and DAS is soft matching. The concepts of the stroke-box, image-box, trend quadrant, and similarity are used to describe the images characteristics for soft matching. The reduction in strict user input rules in soft matching improves the usability and therefore creates a great advantage. The denser grid granularity enables users to design a longer password, enlarging the practical password space and enhancing security. Meanwhile, YAGP adopts a triple-register process to create multi-templates, increasing the accuracy and memorability of characteristics extraction. Experiments illustrate the effectiveness of YAGP.  相似文献   
998.
一种新型CMOS电流控制电流传输器   总被引:1,自引:0,他引:1  
提出了一种基于共源共栅电流镜的CMOS电流控制电流传输器(CCCⅡ)电路。该电路由跨导线性环电路和共源共栅电流镜构成。相对于基于基本电流镜的CMOS电流控制电流传输器,该电路具有输出阻抗更大以及电流传输精度更高的优点。分析了电路的工作原理,给出了实验结果,验证了电路的正确性。  相似文献   
999.
设计了一个工作频段在902 MHz~928 MHz,输出功率为19 dBm、功率增益高达27 dBm、应用于射频识别(RFID)系统的驱动级功率放大器。为缩短功率放大器的研发周期并提高其开发的成功率,设计运用了仿真优化和实际测试相结合的方法。测试结果与仿真结果的高度一致性验证了这种方法的有效性。  相似文献   
1000.
We propose a nonlinear mathematical model to consider production scheduling and vehicle routing with time windows for perishable food products in the same framework. The demands at retailers are assumed stochastic and perishable goods will deteriorate once they were produced. Thus the revenue of the supplier is uncertain and depends on the value and the transaction quantity of perishable products when they are carried to retailers. The objective of this model is to maximize the expected total profit of the supplier. The optimal production quantities, the time to start producing and the vehicle routes can be determined in the model simultaneously. Furthermore, we elaborate a solution algorithm composed of the constrained Nelder–Mead method and a heuristic for the vehicle routing with time windows to solve the complex problem. Computational results indicate our algorithm is effective and efficient.  相似文献   
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