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41.
Incontinentia pigmenti is an uncommon genodermatosis that occurs in female infants. The characteristic dental defects are partial anodontia and the presence of some peg-shaped teeth. This report describes a patient with incontinentia pigmenti who exhibited multiple missing teeth in both arches. The patient had malpositioned teeth and decreased occlusal vertical dimension associated with the missing teeth. Orthodontic treatment was required for prosthetic purposes. The dental anomalies of incontinentia pigmenti and the treatment procedure are presented. 相似文献
42.
The fast Fourier transform (FFT) algorithm has been used in a variety of applications in signal and image processing. In this article, a simple procedure for designing finite-extent impulse response (FIR) discrete-time filters using the FFT algorithm is described. The zero-phase (or linear phase) FIR filter design problem is formulated to alternately satisfy the frequency domain constraints on the magnitude response bounds and time domain constraints on the impulse response support. The design scheme is iterative in which each iteration requires two FFT computations. The resultant filter is an equiripple approximation to the desired frequency response. The main advantage of the FFT-based design method is its implementational simplicity and versatility. Furthermore, the way the algorithm works is intuitive and any additional constraint can be incorporated in the iterations, as long as the convexity property of the overall operations is preserved. In one-dimensional cases, the most widely used equiripple FIR filter design algorithm is the Parks-McClellan algorithm (1972). This algorithm is based on linear programming, and it is computationally efficient. However, it cannot be generalized to higher dimensions. Extension of our design method to higher dimensions is straightforward. In this case two multidimensional FFT computations are needed in each iteration 相似文献
43.
44.
Rohat MelikEmre Unal Nihan Kosku PerkgozChristian Puttlitz Hilmi Volkan Demir 《Microelectronic Engineering》2011,88(3):247-253
In this paper, we present and demonstrate RF-MEMS load sensors designed and fabricated in a suspended architecture that increases their quality-factor (Q-factor), accompanied with an increased resonance frequency shift under load. The suspended architecture is obtained by removing silicon under the sensor. We compare two sensors that consist of 195 μm × 195 μm resonators, where all of the resonator features are of equal dimensions, but one’s substrate is partially removed (suspended architecture) and the other’s is not (planar architecture). The single suspended device has a resonance of 15.18 GHz with 102.06 Q-factor whereas the single planar device has the resonance at 15.01 GHz and an associated Q-factor of 93.81. For the single planar device, we measured a resonance frequency shift of 430 MHz with 3920 N of applied load, while we achieved a 780 MHz frequency shift in the single suspended device. In the planar triplet configuration (with three devices placed side by side on the same chip, with the two outmost ones serving as the receiver and the transmitter), we observed a 220 MHz frequency shift with 3920 N of applied load while we obtained a 340 MHz frequency shift in the suspended triplet device with 3920 N load applied. Thus, the single planar device exhibited a sensitivity level of 0.1097 MHz/N while the single suspended device led to an improved sensitivity of 0.1990 MHz/N. Similarly, with the planar triplet device having a sensitivity of 0.0561 MHz/N, the suspended triplet device yielded an enhanced sensitivity of 0.0867 MHz/N. 相似文献
45.
P. Forssell M. Cetin G. Wirtanen Y. Mlkki 《European Journal of Lipid Science and Technology》1990,92(8):319-321
The antioxidative properties of oat oil and its fractions were studied using the Rancimat method and lard, tallow and soybean oil as substrates. Oat oil extracted with isopropanol increased the induction time of oxidation of lard and tallow from 2 to 8-fold compared with the corresponding times without antioxidants, when applied at 1.0 to 5% concentrations. The same increase in stability was achieved with 0.25 to 1.5% concentrations of the separated fractions. The most effective fraction was the lecithin fraction isolated by supercritical CO2 extraction. Almost equal results were achieved with a single-step ultrafiltration. Effects on the stability of soybean oil were similar but weaker. 相似文献
46.
Yasuhiro Kurokawa Cetin Toy William D. Scott 《Journal of the American Ceramic Society》1989,72(4):612-616
The AIN–W Interfaces in a cofired multilayer AIN substrate were observed using an optical microscope, scanning electron microscope (SEM) and transmission electron microscope (TEM). Optical and SEM observations showed an intricate intricatelocking AIN-W grain structure at the interface. After the W pad was removed from the substrate with a NaOH etchant, the surface morphology of the W metal at the interface side was found to be very rough, with a small-grain microstructure compared with that at the free surface side. Electron microprobe analyses using SEM revealed that there was no diffusion of either W or Al at the interface at the order of a few micrometer's resolution. Bright-field images, dark-field images and selected area electron diffraction (SAD) patterns using TEM indicated there was no secondary phase between AIN and W. However, scanning transmission electron microscopy using an energy dispersive X-ray detector revealed that there was a 200-nm thick W diffusion layer from the interface into the AIN ceramics. It was concluded that the high adhesion strength between the W conductor and the AIN substrate (>20 MPa) was not due to any secondary phase but to mechanical interlocking of AIN and W during cofiring. 相似文献
47.
Stochastic differential equations and geometric flows 总被引:2,自引:0,他引:2
In previous years, curve evolution, applied to a single contour or to the level sets of an image via partial differential equations, has emerged as an important tool in image processing and computer vision. Curve evolution techniques have been utilized in problems such as image smoothing, segmentation, and shape analysis. We give a local stochastic interpretation of the basic curve smoothing equation, the so called geometric heat equation, and show that this evolution amounts to a tangential diffusion movement of the particles along the contour. Moreover, assuming that a priori information about the shapes of objects in an image is known, we present modifications of the geometric heat equation designed to preserve certain features in these shapes while removing noise. We also show how these new flows may be applied to smooth noisy curves without destroying their larger scale features, in contrast to the original geometric heat flow which tends to circularize any closed curve. 相似文献
48.
A nonparametric statistical method for image segmentation using information theory and curve evolution. 总被引:10,自引:0,他引:10
Junmo Kim John W Fisher Anthony Yezzi Müjdat Cetin Alan S Willsky 《IEEE transactions on image processing》2005,14(10):1486-1502
In this paper, we present a new information-theoretic approach to image segmentation. We cast the segmentation problem as the maximization of the mutual information between the region labels and the image pixel intensities, subject to a constraint on the total length of the region boundaries. We assume that the probability densities associated with the image pixel intensities within each region are completely unknown a priori, and we formulate the problem based on nonparametric density estimates. Due to the nonparametric structure, our method does not require the image regions to have a particular type of probability distribution and does not require the extraction and use of a particular statistic. We solve the information-theoretic optimization problem by deriving the associated gradient flows and applying curve evolution techniques. We use level-set methods to implement the resulting evolution. The experimental results based on both synthetic and real images demonstrate that the proposed technique can solve a variety of challenging image segmentation problems. Futhermore, our method, which does not require any training, performs as good as methods based on training. 相似文献
49.
S Aksoylar S Ak?it S Ca?layan I Yaprak R Bakiler F Cetin 《Canadian Metallurgical Quarterly》1997,39(2):215-217
A case of large fronto-temporo-parietal epidural hematoma associated with ipsilateral retrobulbar hematoma is reported. A 24-year-old man soon after a head injury due to a traffic accident became comatose with anisocoria and hemiplegia and developed exophthalmos, conjuctival chemosis, downward and lateral displacement of the eyeball. CT scan of the brain and the orbit showed the large epidural clot communicating with an ipsilateral retrobulbar hematoma through a sphenoid bone fracture. The patient underwent emergency surgery. Postoperatively, he improved and was discharged in good conditions. On follow-up one month later he was symptoms free. The available literature is reviewed: our case seems to be the fifth reported. 相似文献
50.
Management of non-resectable pelvic tumours by intra-arterial local chemotherapy was shown to be beneficial but systemic toxicity limits its use. To overcome this problem isolated pelvic perfusion (IPP) was introduced as an alternative. This study summarizes our preliminary experience with IPP in the treatment of 18 non-resectable pelvic tumours [recurrent rectal adenocarcinoma (six), soft tissue sarcoma (STS) (five), bone tumour (three), epidermoid carcinoma (two), prostatic adenocarcinoma (one), malignant melanoma (one)]. Results of IPP were regarded as complete remission (CR), partial remission (PR), stable disease (SD) and disease progression (DP) according to the changes in three parameters including; scoring in pain, tumour marker and tumour size measurements. Complete and partial remission were established in five (27%) and seven (39%) patients respectively indicating a benefit ratio of 66%. Objective pain relief was encountered in 53% of the cases. All patients with STS had undergone further surgical treatment after IPP with successful curative resections in four. No residual tumour was found at the laparotomy of the fifth patient. Presenting symptom of the prostatic adenocarcinoma patient was symptomatic hypoglycaemia which resolved completely after IPP. To our knowledge, this represents the first case reported in the English literature in whom tumour related hypoglycaemia was successfully managed by IPP. In conclusion; management of non-resectable pelvic tumours by IPP seems to offer serious palliation and increase in the quality of life without any systemic toxicity. Our preliminary experience suggests even resectability may be achieved in a number of patients especially in those with STS. 相似文献