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A ground surface roughness measurement method is proposed to address current problems in the use of machine vision technology to measure roughness: the calculations are complex, and the measurement process is largely affected by the light source. Based on the area of diffusion regions between the virtual images formed by a light source on ground surfaces with different roughness levels are different, a reference light source containing two base color is designed. Red and green color space-based color distribution statistical matrices, as well as corresponding overlap indices, are proposed. A relationship model between overlap index and roughness is constructed. The effect of light source brightness and texture direction on the relationship model is discussed based on the experimental data. The results demonstrate that the surface roughness measurement method, which is based on the overlap degree of the color image, has relatively high accuracy and a relatively wide measurement range and is, to a certain degree, robust to the brightness of the light source and the texture direction. The surface roughness measurement method has huge potential for engineering applications.

In electromagnetic launch (EML) applications, a compensated pulsed alternator is an effective form of pulsed power supply because of its high energy density and power density. The basic advantages of compensated pulsed alternators for EML applications are their higher energy density than capacitors and their export ac output that is suitable for transmission and transformation. In general, external excitation is adopted as a form of self-excitation or pulse excitation in compensated pulsed alternators with an iron core or air core. Using this form not only results in heavy and bulky components but also complicates and reduces the reliability of the system. This paper proposes a novel compensated pulsed alternator that is excited by permanent magnets (PMs) and equipped with an iron core or air-core stator. This system does not require any excitation converter or brush–slip ring, thereby making it more reliable, less massive, and less voluminous than the system with self-excitation or pulse excitation. In addition, analytical models are introduced to simulate the air-gap magnetic distribution, back-electromotive force, pulsed current wave, discharge torque, and energy exchange of this machine. A scale-model prototype of the PM-compensated pulsed alternator is designed, fabricated, and tested. The actual output voltage waveform and pulsed current waveform are sampled and compared with the predicted ones. The results show that the design of the PM compulsator is feasible and reliable.

With the development of the social economic conditions, society has a great change to the ability of the business management major students compare with the past, which requires colleges and universities to reform the teaching process. Combined with the relevant requirements of the project of training the talents of management major, we reform the management course system from the course setting to the teaching material, from the teaching content to the design of practice, from the teaching methods to the teaching method. We combined with students' own conditions and characteristics, try to explore a set of management course system which is adapted to the students by learning other colleges and universities' reform of management course system and successful practical experience, in order to make the corresponding contribution to achieve the new goals of personnel training.

Background: The mechanisms of neointima formation after synthetic vascular grafting are not clear. The aim of this study was to investigate the intima and perigraft adventitia remodeling process in terms of cell apoptosis versus proliferation after synthetic patch implantation. Methods: Female Merino sheep were randomized equally into two groups and underwent implantion with a patch of gelatin sealed Dacron graft into the left common carotid artery. At 1 and 6 months, grafted vessels were harvested, processed, and assessed. Intimal area and lumen sizes were measured with histologic assessment of eight segments from each animal assisted with image analysis. Immunohistochemical labeling of α-actin and D33 desmin was performed on tissue sections of perigraft adventitia, graft matrix, and intima. Cell proliferation and cell phenotype were determined with double immunohistochemical staining with anti-proliferating cell nuclear antigen and anti-α-actin or antimacrophage antibodies (HAM 56) in perigraft adventitia, graft matrix, and intima. Apoptosis was detected with in situ terminal deoxynucleiotidyl transferase-mediated 2′-deoxyuridine 5′-triphosphate-fluorescence nick end labeling (TUNEL) in perigraft adventitia, graft matrix, and intima. Results: The carotid artery lumen size at 6 months was significantly larger than at 1 month (P ≤ .05). The intimal area was significantly reduced at 6 months compared with 1 month (P < .05). At 1 month and 6 months, perigraft adventitia, graft matrix, and intima showed positive α-actin expression but negative desmin staining. In the anastomotic area, a small number of intimal cells suggested their muscle origin (expression α-actin and desmin). The number of proliferating cells in the intima was significantly greater at 1 month than at 6 months (P = .01). TUNEL-positive cells were significantly greater in the intima at 1 month than at 6 months (P < .05), whereas TUNEL-positive cells were significantly greater at 6 months in the perigraft adventitia (P < .05). HAM 56-positive cells in the intima at 1 month were significantly greater compared with 6 months (P < .05), whereas in graft and perigraft regions, no significant difference was seen between 1 month and 6 months. Conclusion: The cell proliferation and cell phenotype change in intima and perigraft adventitia are associated with thickening of perigraft adventitia and intima at 1 month. The balance between cell proliferation and apoptosis could account in part for the reduction in intima area and perigraft adventitial cellularity at 6 months. (J Vasc Surg 2002;36:371-8.)

The existing machine-vision surface roughness measurement technique extracts relevant evaluation indices from grayscale images without using the strong sensitivity of color information. In addition, most of these measurements use a micro-vision imaging method to measure a small area and cannot make an overall assessment of the workpiece's surface. To address these issues, a method of measuring surface roughness that uses an ordinary light source and a macro-vision perspective to generate a red and green color index for each pixel is proposed in the present study. A comparison test is conducted on a set of test samples before and after surface contamination using the color index and gray-level algebraic averaging, the square of the main component of the Fourier transform in the frequency domain, and the entropy. A strong correlation between the color index and the surface roughness is established; this correlation is not only higher than that of other indices but also present despite contamination and very robust. Verification using a regression model based on a support vector machine proves that the proposed method not only has a simple apparatus and makes measurement easy but also provides high precision and is suitable over a wide measurement range. The impact of the red and green color blocks, the lighting, and the direction of the surface texture on the correlation between the color index and the roughness are also assessed and discussed in this paper.

In the digital signal processing, the NCO (Numerically Controlled Oscillators) has a wide range of applications. In this paper, we have researched and implemented the NCO based on the lookup table algorithm with the VHDL and the ISE tool of Xilinx Inc. Finally, the simulation results indicate that the designed NCO is suitable.