Advanced Materials Research Vols. 468-471

Abstract: In Virtual instrument (VI) established for computer based automated test and control, the process with only single thread has limits when developed for acquiring high speed data, analyzing and displaying them the meaning while. Any interference from another task may block the whole running process and cause data missing. In order to increase the throughput, responding time and multi-task processing efficiency of VI, multi-thread programming with the platform LabWindows/CVI is introduced in this paper. Contents include the two strategies to establish multi-thread program, Thread pool and Asynchronous Timer, and how to protect data with multi-thread programming. Finally, a case study showed a multi-thread VI based on Asynchronous Timer method, with the comparison of performance between single thread and multi-thread program.

Abstract: Information security in Electronic commerce is a very important, and image is one of the important information. Classic image encryption algorithms include Arnold cat transformation, magic square transformation, Hilbert transformation, and the Arnold cat transformation is widely applied and has the best scrambling effect effectively. It puts forward an algorithm of image encryption based on Arnold cat and chaotic map. The experiment results show that the key quantities and scrambling effect are improved obviously, and it is rapid and security.

Abstract: This article introduces the trigger circuit of series SCRs valve and a new trigger circuit is designed for series SCRs valve of TSC. The trigger circuit is driven by voltage source and a high voltage cable is used for insulation of the pulse transformer. The trigger circuit has simple structure and a steep front of gate-current. This unit is used in 10 kV thyristor switched capacitor (TSC) reactive power compensation device, and the results verify its feasibility.

Abstract: This paper describes how to use a posture sensor to validate human daily activity and by machine learning algorithm - Support Vector Machine (SVM) an outstanding model is built. The optimal parameter σ and c of RBF kernel SVM were obtained by searching automatically. Those kinematic data was carried out through three major steps: wavelet transformation, Principle Component Analysis (PCA) -based dimensionality reduction and k-fold cross-validation, followed by implementing a best classifier to distinguish 6 difference actions. As an activity classifier, the SVM (Support Vector Machine) algorithm is used, and we have achieved over 94.5% of mean accuracy in detecting differential actions. It shows that the verification approach based on the recognition of human activity detection is valuable and will be further explored in the near future.

Abstract: This article put forward a kind of PID compound control algorithm, the arithmetic is the integration of fuzzy control technique and PID control technique, it possesses both the flexible and strong robust advantage of fuzzy control and the precise character of PID control. A simulation study of the system shows that the algorithm is of reliability, high precision and strong ability of anti-interfere and robustness.

Abstract: The uncertainty of the geographical environment and climate in the power transmission lines leading to the safe operation of the power grid lines become an important indicator of reliability. Transmission line monitoring system monitors transmission line mechanical parameters and meteorological data in the operation. In order to realizing monitoring, prediction and positioning accurately in typical faults, ZIGBEE and GPRS are adopted to transmit mechanical parameters and meteorological data in monitoring system.

Abstract: Antihypertensive peptides derived from soybean protein isolated were separated by ultrafiltration technology. The antihypertensive peptides was ultrafiltrated by the membrane with 1000 molecular weight cut-off. The effects of pressure, concentration，temperature and time during ultrafiltration were studied. In the experiment the method of response surface has been utilized to improve the ultrafiltrate film with 1000, and the best appropriate ultrafiltrate condition is that: ultrafitration pressure 0.38Mpa, PH value 6, the temperature 44°C, the time 100min. The analytical predictor of response surface under this ultrafiltration condition is 29.09912 L/(m2h), which has been verified in verification test.

Abstract: A three-layer structured Back Propagation (BP) neural network has been proposed to automatically predict the height of surface-breaking crack, 28 group data including different K values of transducers and the beam path distances obtained directly from the tip echo experiment have been taken into consideration as the training samples. It is shown that the predictions of current network are in good consistence with the real crack heights, the robustness testing demonstrates that the current neural network has its feasible expansibility to be utilized in practical engineering applications.

Abstract: To detect and track eye images, distinctive features of user eye are used. Generally, an eye-tracking and detection system can be divided into four steps: Face detection, eye region detection, pupil detection and eye tracking. To find the position of pupil, first, face region must be separated from the rest of the image using bag of pixels, this will cause the images background to be non effective in our next steps. We used from horizontal projection, to separate a region containing eyes and eyebrow. This will result in decreasing the computational complexity and ignoring some factors such as bread. Finally, in proposed method points with the highest values of are selected as the eye candidate's. The eye region is well detected among these points. Color entropy in the eye region is used to eliminate the irrelevant candidates. With a pixel of the iris or pupil can be achieved center of pupil. To find the center of pupil can be used line intersection method in the next step, we perform eye tracking. The proposed method achieve a correct eye detection rate of 97.3% on testing set that gathered from different images of face data. Moreover, in the case of glasses the performance is still acceptable.

Abstract: [Objective] By understanding the past and present development of water resources and development advantages of vegetable industry in Northwest Hebei, as well as exacerbated desertification caused by the conflict between water shortage and vegetable industry development conflicts. We recommend the development of sustainable utilization of water resources available for the vegetable industry sustainable development strategy. [Methods] Methods are taken as a combination of scientific research based on field surveys, questionnaires and statistical analysis, theory and practical testing. [Results] Northwest Hebei water resources development has gone from earth-rock wells and small-scale channels of human excavation, excavation of manual work and machinery to the rapid growth of vegetable irrigable land. As a consequence of insufficiency of average annual rainfall in the region and the limited capacity of the groundwater recharge, water shortage has become a bottleneck element as a constraint to the development of vegetable industry. The conflict between water shortage and vegetable industry has intensified desertification. [Conclusion] The vegetable industry development should base itself on the carrying capacity of water resources as a priority. Sustainable utilization of water resources and scientific development can ensure and promote the sustainable development of vegetable industry.