Applied Mechanics and Materials Vols. 249-250

Abstract: Endoscopic surgery is increasing for minimally invasive treatment in recent years.But the conventional two-dimensional endoscope technique cannot provide three-dimensional information for surgeon. Lacking depth and other 3D information often made doctorshave to carry out the surgery depending heavily clinical experience.In response to the above described issues,this paper proposed a method based on improved SIFT algorithmto recover 3D structure information of the endoscopic environment, with the help of an optical tracking system which can provide the orientation of the camera in real time. The proposed approach is evaluated on sequence digital images gotten from an 1394 camera and the experimental results show that the proposed approach iseffective.

Abstract: Image representation is a key issue among many image processing tasks. By considering the problems faced by current general image representation methods, such as excessive computing amount, sensitivity to noise, lack of self-adaptability etc, a novel image representation method based on biologic visual mechanisms is proposed in this paper. Through simulating the primary visual cortex to realize the sparse representation of outside image it also introduced the synchronization mechanism to make it more accordant with visual system. Finally the presented method was verified by applying it to compress natural images and digital literature images respectively. The result showed that this new representation method is better than the general sparse representation method on both aspects of compression ratio and noise sensitivity.

Abstract: The genomic DNA of Bacillus pumilus AC-4 strain, which were separated by our laboratory, was used as the DNA template. The β-1,4-endoglucanase gene fragment was amplified by PCR (Polymerase Chain Reaction). The PCR product was recovered and cloned into plasmid pMD-19T. The DNA sequence analysis showed that the length of the amplified fragment is 1898bp, which has 95% similarities to the β-1,4-endoglucanase gene sequence from other Bacillus strains. Sub-cloned the recombinant plasmid which containing β-1,4-endoglucanase and digested with BamHI and EcoRI. And then linked with the expression plasmid pGEX-4T-1 and transferred into the competent E. coli BL21 for expression. The result of protein electrophoresis showed that there has expressed protein whose molecular weight is about 70 kDa. Measured the enzyme activity of the expression protein of recombinant strains is 0.92 IU/mL, which is 1.52 times as the start strains.

Abstract: The necessary theoretical and methodological foundation is provided by means of which the human mastication process could be studied and reproduced in a digital dynamic way. This paper reviews previous publications and elaborates further mathematical analysis and mechanical analysis of biomechanical functions, explaining the characteristics of human mandible, Temporomandibular joints (TMJs), muscles based on clinical anatomy, and analysing the inter-relationship and inter-reflection between each component of this multi-body assembled organism.

Abstract: Surface electromyography (SEMG) signals of cervical muscles are investigated by time-frequency analysis and biomechanics analysis. Medium frequency (MF) and integrated electromyography (IEMG) are extracted and analyzed from SEMG signals of subjects’ upper trapezius. The Experimental results show that the value of MF decreases and the value of IEMG increases with the increase of fatigue of the vertical muscles. Also, the values of IEMG at different testing points of same cervical muscle are compared. The value of IEMG with higher resistant moment is higher than that with lower resistant moment. That means the muscle with high resistance moment is easier to be fatigue. This investigation is important for people, especially those who work/read with bowing head or before computer for a long time, to prevent cervical spondylosis.

Abstract: Bone drilling is a common procedure to produce hole for screw insertion to fixate the fracture devices and implants during orthopaedic surgery. A major problem which is encountered during such a procedure is the increase in temperature of the bone due to the plastic deformation of chips and the friction between the bone and drill. This increase in temperature can result in thermal osteonecrosis which may delay healing or reduce the stability and strength of the fixation. In the present work, prediction of temperature in drilling of polymethylmethacrylate (PMMA) (as a substitute for bone) is carried out using fuzzy logic. The effectiveness of the fuzzy model is compared with the experimental results. Good agreement is observed between the predictive model values and experimental values which indicates that that the developed model can be effectively used to determine the temperature in the bone drilling.