Advanced Materials Research Vols. 301-303

Abstract: This paper expounds the concept and principle of data protection. According to the request of AC motor test and control system, the paper uses thread safe queues technology of LabWindows/CVI to protect motor’s data. Finally, effect of thread safe queues is validated through experiments, it proves that data protection can properly reflects motor’s status.

Abstract: A novel method to measure small phase in micro-holography is discussed. It originated from Zernike phase contrast imaging technique, which has been a successful linear phase-to-intensity mapping approach toward phase object. Instead of phase-changing plate, an interference phase contrast technique that is based on in-line holography is utilized to obtain a hologram in the proposed method. The intensity distribution of hologram presents a monotone function with respect to phase distribution of phase object. Thus, the phase can be directly detected through hologram without phase unwrapping. In the work, the contrast of hologram is analyzed toward various phase difference between object wave and reference wave. An optimal solution to measure small phase of phase object is developed, which extends the measuring range of phase. Simulation on a computer is performed to validate theoretically the proposed method.

Abstract: In order to meet oil production requirement, the automatic detection and classification system for recycled drill pipe is badly needed. After carefully analyzed the inspection process, a novel NDT method composed of MFLT (magnetic flux leakage testing) and UT (ultrasonic testing) on drill pipe rotating is designed. Afterwards, a geometrical dimensions measurement system for drill pipe by laser is developed. Additionally, drill pipe is automatically classified with the application of database and fieldbus technologies. Finally, the automatic detection and classification system is formed, which works stably and has a good application effect.

Abstract: In recent years SAR interferometry has become a widely used technique for measuring altitude and displacement of the surface of the earth. Phase unwrapping of the interferometric SAR is a very important step to obtain an accurate DEM(Digital Elevation Model)[1,2,3],and phase unwrapping is not only crucial in InSAR but also a major source in InSAR errors. Therefore, with GAMMA software, VC++ and MATLAB coding implementing six kinds of phase unwrapping approaches ,this paper presents the best method for different situations through two sets of experimental results used for analysing and comparing run time and precision. In the plain and alpine area, the best phase unwrapping methods are separately Goldstein branch-cut method and Minimum Cost Network Flow method.

Abstract: CG-5 is new automatic land relative gravimeter developed by Canada Scintrex Company. Gravity vertical gradient can be measured by CG-5. This article mainly aims at precision analysis of the gravity vertical gradient measurement based on CG-5.This paper analyzes the error sources and error propagation formulae. In the end, it shows relation between altitude differences and observation sets in certain accuracy requirement. Results show that the precision of CG-5 vertical gradient measurement is improved when altitude difference and observation set increase. In vertical gradient measurement, 13 observation sets are needed with altitude difference at 2m to obtain the precision of ±20E.

Abstract: The high resolving power camera was often used to improve the precision of measuring system although its price is high, because the accuracy of image measure was limited by the pixel resolving ability of camera. A method of one dimension gray level quadrature sub-pixel to detect edge was presented. This method was applied to measure the displacement of measuring head on 3-coordinate measuring machine. The data of test was shown that this system can distinguish displacement 0.001mm. it is higher accuracy than pixel level. So this method is convenient and fast , fit to track and measure the moving object. It is obvious that this method can save the cost of hardware.

Abstract: The paper has research and analyzed the arithmetic of shape features extraction and similarity metric, and adopted the Euclid distance metric, and according to the image database of the bird which from UIUC and the database of chair, strawberry from Caltech 101, the Hu invariants moments features extraction are validated. Compared these experiment results, at the different database, some image which has simple background and different shape object can be obtained the better retrieval effect.

Abstract: A design of wireless pulse signal acquisition system for status monitoring of ship navigators has been presented. The system employs STC12LE5608AD as controller for timing acquisition of the pulse signal. And then the data are written to the register of CC2500 via SPI interface and transmitted. When the receiver takes the data, the MCU reads the data from the receiver register of CC2500. Finally the MCU send the data to computer via UART for display and further processing. Wireless transmission insures that the system can analyze the degree of navigators' fatigue objectively and quantifiably without affecting their operation of the ship. The system serves as a warning for fatigue navigation. This system has advantages of low power consumption and portability. It has the practical value of safe navigation of ships.

Abstract: The aim of this article is to study the texture features of cingulum in patients with Alzheimer's disease (AD) and mild cognitive impairment (MCI) based on magnetic resonance images, and explore the texture differences derived from different gender among each group. Texture analysis was performed on 7 AD patients, 14 MCI patients and 11 normal controls (NC). Texture features extracted from gray level co-occurrence matrix and run-length matrix were analyzed between each two groups. The results showed that texture features of the anterior cingulum had significant differences in the multiple comparisons and features of the posterior cingulum had significant differences between AD and MCI group as well as AD and NC group. There were significant differences between AD and MCI group as well as AD and NC group in male’s cingulum. While in female’s cingulaum, the differences were founded between AD and NC group. The results indicated that the pathological changes in cingulum could be reflected by texture features and the pathological changes may be different in the two genders.

Abstract: Corporation work piece length measure system based on digital image processing technology. CCD vidicon is used as the image capture equipment. Image signal are converted into 8 bits digital code stream by CMOS image sensor chip OV9650. DSP chip of TI is used as the core of image processing in the scheme. Peripheral SDRAM are expanded through peripheral bus to save the large amounts of temporary data in data processing to reduce the time for image processing. Median filtering is adopted in image enhance of the object image. The length of rectangle work piece can be measured in the distance by untouched way by improved edge recognition algorithm in real time. The measurement result is displayed by LCD. Meanwhile the measure system communicates with PC through communication interface. It has been proved that the system can guarantee real-time and high accurate. It’s a typical instance of DSP and digital image processing technology used in industry.