Advanced Materials Research Vols. 301-303

Abstract: Based on the wind tunnel test of a mass culture activity center, the influence of the shape change of the structure with abnormal roofing on the wind loads shape coefficient were studied. The result from the test was compared with the values from the related items in the《load code for the design of building structure》^[1]. Research results shows: the shape coefficient of the abnormal roofing structure is unfavorable to take norms similar structure shape coefficient values, need to measure it through wind tunnel tests.

Abstract: The angular misalignment of a three-point supported dual-span rotor system is discussed. Vibration measurement for coupling misalignment is taken in this paper by using the model test rig, and the rotor vibration response characteristics with different misalignment quantities and different rotating speed are compared. Based on the finite element method, researches on the three-point supported dual-span rotor system are made, and then the simulation and experimental results are compared. Both the simulation and the measurement are compared to show the features. The results show that the amplitudes of the misaligned rotor vary with rotating speeds and misalignment angles, and the center orbits of the misaligned rotor change into ellipses with the increase of misalignment, together with double harmonic responses.

Abstract: In this paper, an adaptive edge detection method (Canny operator and Otsu threshold selection based adaptive edge detection method - COAED) is proposed. The COAED method combines a new hybrid filter with Canny operator to avoid the conflict of Canny operator between noise removing and edge locating, and uses Otsu threshold selection method to determine Dual-threshold of Canny operator adaptively. The new hybrid filter firstly judges whether the pixel is polluted by impulse noise, and then uses a corresponding filter to process the current pixel. A median filter is used if the pixel is thought to be impulse noise; otherwise an improved mean filter is selected to weaken the Gaussian noise. After the image is smoothed by the hybrid filter, a Canny operator with small Gaussian variance is used to extract edge. Because only part of Gaussian noise remains, Canny operator with small Gaussian variance can suppress the noise and preserve the edge effectively. Using the gauge image polluted by hybrid noise as experiment object, the performance of COAED method is evaluated qualitatively and quantitatively. Experimental results show that the COAED method is superior to Canny operator.

Abstract: By research, we can realize definitely the relationship between the urban transportation system mode and containable development; meanwhile, it suggests the evaluation methods evaluation contents and guideline of Large-sized and middle-sized civic traffic problems. According to the civic traffic containable development basic theory, the major action factors of the civic traffic containable development and the establishment of the civic traffic containable development evaluation guideline system. Afterwards, this paper takes main factors and weight to use the found evaluation system.

Abstract: With the development of the transportation, the county-country highway network has the more and more important function in the transportation network. Therefore, it is necessary to establish the scientific method evaluating the total function of the county country road network, so as to support decision for the synthetically transportation planning and management. The paper evaluates the whole construction level, layout quality and total capacity of the county-country highway network from the standpoint of holistic planning and synthetically transportation development. The status of the existent network is investigated and analyzed. Then the corresponding evaluating guideline system and method is put forward. Applying the proposed system and method, the paper analyzes the performance of some county highway network in Nanchong city and brings forward some improvement suggestions.

Abstract: By making use of LabVIEW, this paper emulates the Time-To-Count measuring system with Geiger-Mueller counter. Results of the emulation indicate that compared with the conventional mode of pulse counting, under the condition of higher intensity of ionizing radiation, method of Time-To-Count can avoid negative effect of Geiger-Mueller counter’s long dead-time. However with ionizing radiation attenuating, the advantage of Time-To-Count will disappear gradually. According to the emulation, this paper also puts forward some suggestions to improve the Time-To-Count measuring system.

Abstract: Direct digital frequency synthesis (DDFS) technology is applied widely in traditional fields which need signal source since it has a lot of advantages such as high frequency resolution, fast frequency setting and conversion speed and so on. Based on the working principle of DDFS, it is very important to calculate the phase control word when synthesizing the continuous adjustable phase difference signals. To address the shortcoming of large computation, low efficiency of phase difference setting, more storage space occupied or significant cumulative errors of phase setting when calculating phase control word with traditional methods, a novel algorithm for computing phase control word is studied in this paper. This new method does not need large computation and more space and simultaneously it can decrease the error greatly, which plays an important role in improving the phase setting speed and precision in signal generator.

Abstract: Spherical-cymbal transducer, which is derived from the traditional cymbal transducer, has demonstrated better vibration displacement and resonance frequency performance than the traditional cymbal transducer. In order to realize the optimal design of the spherical-cymbal transducer, orthogonal experiment is used to optimize the design parameters of the spherical-cymbal transducer. Weighted comprehensive point-rating method (WCPM) is used to process the orthogonal experiment results for multi indexes, and intuitionistic analysis of the weighted comprehensive score is used to optimize the level of each design parameter. The optimal combination of all design parameters is gained. Test results show that the optimized spherical-cymbal transducer has the best integrative performance.

Abstract: Strategy use is a mental operation which aims directly at its target. In order to investigate brain activity during mental arithmetic strategies using, subtraction answers-discrimination tasks were used through 8 healthy subjects with the Event-related Potentials (ERPs) technique. The results showed: (1) The principal components of ERP were: N1, P1, P2, P300 and N400. (2) At the F3, C3 point, stage 4 induced more negative wave than stage 1; At F4, C4, P3 and P4 point, stage 4 induced more positive wave than stage1. (3) Activation of brain areas mainly included Temporal lobe, Prefrontal cortex and Parietooccipital. (4) With the subjects gradually skilled in using strategies, activated brain region gradually moved from back to front; meanwhile the right side had higher active level than the left of brain. Further exploration need to describe more detailed brain potentials during mental arithmetic strategies using in other conditions.

Abstract: Monitoring the pressure outside casing of oil-water wells is significant to prevent and reduce casing damage. Aiming at the problem of permanently monitoring the pressure outside casing of oil-water wells, according to FBG sensing principles, FBG is packaged by FRP, pressure sensitivity program is designed, make sure strain for four bending points of FBG sensor are well-distributed, take sinusoidal corrugated diaphragm as elastic element, a monitoring sensor with temperature compensation is developed. Pressure performance calibration test of the sensor is conducted, experimental results show that the sensor has stable performance and fine temperature compensation capability, the pressure measuring range is, sensitivity is 109.