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排序方式: 共有236条查询结果,搜索用时 875 毫秒
21.
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
22.
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
23.
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
24.
The applications of biometric technology for automated personal identification become ubiquitous. Iris recognition is well known for high accuracy and reliability among the biometric traits. This paper presents an efficient noise-removing approach for non-cooperative iris recognition systems. Proposed method removed the noise factors including eyelids, eyelashes, reflections, out of framework, pupil and sclera. The novelty is to detect eyelashes and reflections through finding appropriate thresholds using a procedure called statistical decision making. The eyelids are detected using parabolic Hough transform in normalized iris image to increase computational speed. In addition, a coarse-to-fine strategy for accurate and fast iris localization is proposed. The Gabor-wavelet and a novel encoding strategy proposed in our previous work are also used here to generate the iris codes. We elaborate the principle of mask code generation to assign noisy bits in an iris code to exclude them in matching step. Experimental results on CASIA-IrisV3-Interval database show superiority of the proposed scheme among other state-of-the-art methods available in the literature. 相似文献
25.
M. D. Murthy Peri Ivin Varghese Dong Zhou Arun John Chen Li Cetin Cetinkaya 《Particulate Science and Technology》2007,25(1):91-106
Removal of sub-100 nm particles from substrates such as wafers and photo masks is an essential requirement in semiconductor, microelectronics, and nanotechnology applications. The proposed laser-induced plasma (LIP) based approach is an effective technique for removal of sub-100 nm particles, as the minimum tolerable particle on the substrates shrinks to sub-100 nm levels with each technological node. In the current study, our progress in sub-100 nm particle removal is reviewed, and the results of the kinetic theory simulations conducted to understand the dynamics of the gas molecule-nanoparticle interactions excited by the shock front are discussed. It is shown from the simulations and experiments that particles as small as sub-100 nm can be successfully detached. To explain possible mechanisms for the nanoparticle detachment in nanoscale, the concepts of rolling resistance moment and rocking motion are utilized as novel detachment mechanisms. The pressure experiments illustrate that the peak pressure levels achieved with the LIP shock wave fields are below damage thresholds of most substrate materials. The potential of the proposed approach as a practical noncontact, dry, fast, and damage-free method for removal of sub-100 nm particles is discussed. 相似文献
26.
BACKGROUND: To examine the effect of endothelin-1 (ET-1) on spontaneous contractile activity and the effects of nimodipine and isradipine on ET-1-induced contractile responses in myometrial strips isolated from normal pregnant and preeclamptic women. MATERIAL AND METHODS:. Isolated myometrial strips were obtained from seven normal pregnant and seven preeclamptic women undergoing elective cesarean section and the strips were mounted in organ baths for recording of isometric tension. The effect of increasing concentration of ET-1 on spontaneous contractions and effects of increasing concentration of nimodipine and isradipine on ET-1-induced contractions were recorded. RESULTS: ET-1 dose-dependently (10(-11)-10(-8) M) increased the amplitude and frequency of spontaneous contractions in all myometrial strips obtained from normal pregnant and preeclamptic women. The increase in the amplitude of contractions in preeclamptic strips was significantly higher than that of normal strips. The increase in amplitude of contractions in normal and preeclamptic strips reached statistical significance beginning from the concentrations of 10(-9) M and 10(-11) M, respectively. ET-1 (10(-8) M) also increased the basal tone of all myometrial strips isolated from normal pregnant and preeclamptic women. When ET-1 (10(-8) M)-contracted myoinetrial strips were exposed to increasing concentrations of nimodipine (10(-6)-3x10(-5)M) and isradipine (10(-5)-3x10(-4) M), nimodipine and isradipine dose-dependently decreased the amplitude and frequency of contractions. CONCLUSIONS: The increase in contractile response with ET-1 was significantly higher in myometrial strips isolated from preeclamptic women compared to those of myometrial strips isolated from normal pregnant women. These increases in contractile response are at least in part mediated by dihydropyridine-sensitive calcium channels, since they were significantly reduced in the presence of increasing concentrations of nimodipine and isradipine. 相似文献
27.
C Kalkan H Cetin E Kaygusuzoglu B Yilmaz M Cift?i H Yildiz A Yildiz H Deveci AM Apaydin H Ocal 《Canadian Metallurgical Quarterly》1996,44(3):335-340
We have investigated the toxicity of dose-escalation of BCNU, etoposide and melphalan ('BEM') chemotherapy with autologous stem cell transplantation in patients with haematological malignancies. Seventy-two patients with haematological malignancies were treated with BCNU (600 mg/m2, 450 mg/m2 or 300 mg/m2), etoposide 2 g/m2 and melphalan 140 mg/m2 followed by autologous bone marrow transplantation (ABMT), n = 51, or autologous peripheral blood progenitor cell transplantation (APBPCT), n = 21. Liver and pulmonary function was monitored pretransplant and at regular intervals post-transplant. Mucositis was graded daily during in-patient stay. There was a significantly higher incidence of symptomatic pulmonary toxicity in the patients who received BCNU at 600 mg/m2 than in the other two groups, and there was a significant increase in the incidence of asymptomatic decrease in carbon monoxide (KCO) in the patients who received BCNU 450 mg/m2. There was no significant difference between the three groups in the incidence and severity of mucositis or in the incidence of transiently abnormal liver function. We conclude that etoposide at 2 g/m2 can be used without unacceptable mucositis. BCNU at 600 mg/m2 is associated with an unacceptably high incidence of lung toxicity, but at 450 mg/m2 there is minimal symptomatic lung toxicity. 相似文献
28.
Alshebeili S.A. Venetsanopoulos A.N. Cetin A.E. 《Signal Processing, IEEE Transactions on》1993,41(4):1576-1588
Recursive and least squares methods for identification of non-minimum-phase linear time-invariant (NMP-LTI) FIR systems are developed. The methods utilize the second- and third-order cumulants of the output of the FIR system whose input is an independent, identically distributed (i.i.d.) non-Gaussian process. Since knowledge of the system order is of utmost importance to many system identification algorithms, new procedures for determining the order of an FIR system using only the output cumulants are also presented. To illustrate the effectiveness of the methods, various simulation examples are presented 相似文献
29.
Untersuchungen des Einflusses unterschiedlicher Kaltverformungen im Zeit- und Kurzzeitschwingfestigkeits-Bereich. Kraftgesteuerte Zug-Druck-Versuche an gelochten Stahlproben. Erhöhung der Lebensdauer der Stähle StE 47 und StE70 im Bereich der Zeitfestigkeit; im Bereich der Kurzzeitschwingfestigkeit dagegen beim Stahl StE 47 deutliche Minderung der Anrißlebensdauer infolge erhöhter Entfestigung, beim Stahl StE70 nur leichte Minderung durch eine höhere Prüffrequenz. 相似文献
30.
Signal recovery from wavelet transform maxima 总被引:6,自引:0,他引:6
The paper presents an iterative algorithm for signal recovery from discrete-time wavelet transform maxima. The signal recovery algorithm is developed by using the method of projections onto convex sets. Convergence of the algorithm is assured 相似文献