1,721,059 research outputs found
Bone temperature estimation during orthopaedic round bur milling operations
No full textHeat generation during orthopaedic bone cutting operations may cause thermal bone damage. During the bone cutting, the maximum temperature occurs at the point of contact between the bone and the cutting tool. However, this temperature is difficult to measure. Many researchers have attempted to measure this temperature using a thermocouple; however, limitations of the thermocouple makes it difficult to determine the maximum temperature at the point of contact. In order to solve this problem, in this study, two infrared thermometers are used to measure the fresh-milled surface temperature, and the maximum temperature was extrapolated by a moving plane heat source solution. The estimated maximum temperature increment varied from 49 to 115 degrees C under various cutting conditions. These results showed that the thermal damage may reach up to 1.9 mm, in depth during round bur milling. A larger feed rate and a smaller cutting depth decreased the maximum temperature. (c) 2004 Elsevier Ltd. All rights reserved
Acoustic Analysis of Interior Space by Using the Geometrical Acoustic Model Including the Phase
No full textA Minimized Hardware Architecture of Fast Phong Shader Using Taylor Series Approximation in 3D Graphics
No full textDirectionally classified eigenblocks for localized feature analysis in face recognition
No full textA new local feature extraction method is introduced. The directionality of local facial regions is regarded as essential information for discriminating faces in our approach, which is motivated by the directional selectivity of the Gabor wavelet transformation, which has been preferred to others for face recognition. The discriminative directional information is forced to be compacted in a few coefficients by applying principle-component analysis with the support of directional classification in the discrete cosine transform domain. The local features extracted by our method are better at discriminating face patterns than previous ones, as was verified by comparison of class-separability results. Also, in face recognition simulations using rigid and flexible face matching strategies based on locally extracted features, our proposed method showed outstanding performance. (c) 2006 Society of Photo-Optical Instrumentation Engineers
A hardware cost minimized fast Phong shader
No full textIEEE Transactions on Very Large Scale Integration SystemsOne of the most successful algorithms that bring realism to the world of three-dimensional (3-D) image generation is the Phong shading, With the continuous improvement in VLSI technology and the demand for higher realism, this algorithm is a menable to the commercially available hardware implementation for real-time rendering in 3-D graphics. Taylor series approximation is appropriate for the hardware implementation of fast Phong shading. However, in this method, the exponentiation of the cosine term requires a very large ROM table, This paper describes the minimization of this overhead in terms of hardware size by proposing an adaptive-compressed nonuniform quantization method. With this method, the ROM table is reduced to 1/64th of the size required for a uniform quantization method while the picture quality is maintained. Due to the reduced ROM table size, the size of the total hardware required for fast Phong shading is minimized to 1/56th of the original size
Combination of warping robust elastic graph matching and kernel-based projection discriminant analysis for face recognition
No full textIn this paper, a robust face recognition algorithm is proposed, which is based on the elastic graph matching (EGM) and discriminative feature analysis algorithm. We introduce a cost function for the EGM taking account of variations in face pose and facial expressions, and propose its optimization procedure. Our proposed cost function uses a set of Gabor-wavelet-based features, called robust jet, which are robust against the variations. The robust jet is defined in terms of discrete Fourier transform coefficients of Gabor coefficients. To cope with the difference between face poses of test face and reference faces, 2 x 2 warping matrix is incorporated in the proposed cost function. For the discriminative feature analysis, linear projection discriminant analysis and kernel-based projection discriminant analysis are introduced. These methods are motivated to solve the small-size problem of training samples. The basic idea of PDA is that a class is represented by a subspace spanned by some training samples of the class instead of using sample mean vector, that the distance from a pattern to a class is defined by using the error vector between the pattern and its projection to the subspace representing the class, and that an optimum feature selection rule is developed using the distance concept in a similar way as in the conventional linear discrimnant analysis. In order to evaluate the performance of our face recognition algorithm, we carried out some experiments using the well-known FERET face database, and compared the performance with recently developed approaches. We observed that our algorithm outperformed the compared approaches
Efficient edge function based anisotropic texture filtering
No full textIn texture mapping, anisotropic filtering methods, which require more texels, have been proposed for high-quality images. Memory bandwidth, however, is still limited by a bottleneck in the texture-filtering hardware. In this paper, we propose anisotropic texture filtering based on edge function. In generating the weight that plays a key role in filtering texels loaded from memory, the edge function gives accurate contribution of texels to the pixel intensity. The quality of images is superior to other methods. For images of the same quality, our method requires less than half the texels of other methods. In other words, the improvement in performance is more than twice that of other methods
Minimized hardware architecture of fast Phong shader using Taylor series approximation in 3D graphics
No full textNew Surface Treatment Method for Improving the Interface Characteristies of CdTe/Hg1-xCdxTe Heterostructure
No full text
- …
