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101.
A progressive fibrous myopathy may result from chronic intramuscular drug abuse. This complication may mimic other rheumatic disorders and early recognition may prevent disability. The patient described here presented with fixed flexion and extension contracture of hips and knees, respectively, after abusing meperidine and other agents for 3 years. Soft tissues of thighs and buttocks were "wood hard," EMG showed absence of action potentials in affected muscles, and biopsy revealed extensive replacement of muscle with dense, acellular fibrous tissue. Possible mechanisms are discussed. 相似文献
102.
Preoperative radiotherapy for adenocarcinoma of the rectosigmoid 总被引:2,自引:0,他引:2
Ninety-seven patients with adenocarcinoma of the rectosigmoid have been treated with high dose (5000-6000 rad) preoperative irradiation from 1960 through 1972 at the University of Oregon Health Sciences Center. Fifty-seven were initially clinically resectable and 40 were initially inoperable. Forty of the 57 initially clinically resectable patients had "curative" resections and are at risk for more than 5 years. An increase in 5-year survival (from 38% to 53%) and an absence of pelvic recurrence have occurred in those patients receiving preoperative irradiation and "curative" resection. Four of the 40 initially inoperable patients are alive without tumor. Three of the four survivors had irradiation and surgery; one had irradiation only. An additional four patients had no evidence of tumor at death. Tumor was totally sterilized by irradiation and nine patients and reduced to microfocal extent in an additional three of the 97 patients. Incidence of complications was no greater than has been reported in a surgical series from the same institution. 相似文献
103.
Acousto-optical PD detection for transformers 总被引:1,自引:0,他引:1
Xiaodong Wang Baoqing Li H.T. Roman O.L. Russo K. Chin K.R. Farmer 《Power Delivery, IEEE Transactions on》2006,21(3):1068-1073
Partial discharge (PD) is one of the factors that could lead to failure of power transformers, leading to power outage and expensive repairs. The acoustic wave induced by PD can be measured and used for monitoring, diagnosing, and locating potential failures in the transformers. Fiber optic sensors have been shown to be attractive devices for PD detection because of a number of inherent advantages including small size, high sensitivity, electrical nonconductivity, and immunity to electromagnetic interference. A fiber optic sensor based on a Fabry-Perot interferometry is constructed by a simple micromachining process compatible with microelectromechanical system technology. The sensors are used in a transformer to measure PD acoustic waves. The experimental results show the sensor not only has an inherent high signal to noise capability, but is able to accurately localize the PD sources inside the transformer. 相似文献
104.
一、冲压模拟仿真技术 背景 从20世纪中期,人们就已经开始利用有限元算法对钣金成形进行模拟仿真研究.1970年至1980年,钣金成形模拟分析技术已被广泛用于分析轴对称、平面变形等问题.近几年,由于可以在计算机中预先对可能出现的问题求解、分析并进行工艺优化,而不是通过实际试模来解决可能出现的问题,为企业带来了巨大的经济效益.因此,冲压模拟仿真技术被企业广泛采用,该技术的不断发展以及高速度、低价格的计算机的出现,使金属成形的加工费用更加低廉. 相似文献
105.
Yueh‐Cheng Chen Ying‐Feng Chen Chien‐Ching Chiu Chin‐Yung Chang 《International journal of imaging systems and technology》2005,15(6):261-265
This article presents a computational approach to the image reconstruction of a perfectly conducting cylinder illuminated by transverse electric waves. A perfectly conducting cylinder of unknown shape buried in one half‐space and scatters the incident wave from another half‐space where the scattered field is recorded. Based on the boundary condition and the measured scattered field, a set of nonlinear integral equations is derived, and the imaging problem is reformulated into an optimization problem. The steady state genetic algorithm is then employed to find out the global extreme solution of the cost function. Numerical results demonstrated that, even when the initial guess is far away from the exact one, good reconstruction can be obtained. In such a case, the gradient‐based methods often get trapped in a local extreme. In addition, the effect of different noise on the reconstruction is investigated. © 2006 Wiley Periodicals, Inc. Int J Imaging Syst Technol, 15, 261–265, 2005 相似文献
106.
Maruo K. Tsurugi M. Chin J. Ota T. Arimoto H. Yamada Y. Tamura M. Ishii M. Ozaki Y. 《IEEE journal of selected topics in quantum electronics》2003,9(2):322-330
This paper reports in vivo near-infrared (NIR) noninvasive blood glucose assay using dermis tissue spectra. We assume that the glucose content in dermis tissue traces the variations in blood glucose. For dermis spectra measurements, epidermis, especially stratum corneum, acts as an interference in skin tissue. Thus, we have developed a method for the selective measurement of dermis tissue spectra, enabling us to obtain better quality spectra for an accurate blood glucose assay. The selective measurement of the dermis spectra realized by using a newly developed fiber-optic probe that consists of source and detector optical fibers separated by 0.65 mm on a skin surface. The light path in the skin tissue for this geometry has been simulated by a Monte Carlo method. The simulation results show that detected light mainly interrogates dermis tissue. As the absorbance signal of glucose in human tissue is extremely small, the quality of the measured spectra is critical for the reliable assay. The present method for blood glucose assay has been applied to one Type 1 diabetic. The correlation coefficient between the blood glucose content predicted by NIR spectra and those measured by finger-prick was 0.928 and the standard error of prediction was 32.2 mg/dL. These results demonstrate the potential of our methodology for noninvasive NIR blood glucose assay. 相似文献
107.
Fast image retrieval using color-spatial information 总被引:1,自引:0,他引:1
Beng Chin Ooi Kian-Lee Tan Tat Seng Chua Wynne Hsu 《The VLDB Journal The International Journal on Very Large Data Bases》1998,7(2):115-128
In this paper, we present an image retrieval system that employs both the color and spatial information of images to facilitate
the retrieval process. The basic unit used in our technique is a single-colored cluster, which bounds a homogeneous region of that color in an image. Two clusters from two images are similar if they are of the
same color and overlap in the image space. The number of clusters that can be extracted from an image can be very large, and
it affects the accuracy of retrieval. We study the effect of the number of clusters on retrieval effectiveness to determine
an appropriate value for “optimal' performance. To facilitate efficient retrieval, we also propose a multi-tier indexing
mechanism called the Sequenced Multi-Attribute Tree (SMAT). We implemented a two-tier SMAT, where the first layer is used to prune away clusters that are of different colors,
while the second layer discriminates clusters of different spatial locality. We conducted an experimental study on an image
database consisting of 12,000 images. Our results show the effectiveness of the proposed color-spatial approach, and the efficiency
of the proposed indexing mechanism.
Received August 1, 1997 / Accepted December 9, 1997 相似文献
108.
沥青路面摊铺过程中由于受各种环境因素的影响,沥青混合料温度以及周围温度的变化是复杂多变的.以侯运高速公路沥青路面表面层摊铺施工为背景,实测了沥青路面摊铺过程中路面周围不同空间、不同时间的温度情况,揭示了沥青路面摊铺时路面周围温度场的时空分布特性,对于沥青路面摊铺施工质量控制有着重要的借鉴意义. 相似文献
109.
Calculating the elastic moduli of steel-fiber reinforced concrete using a dedicated empirical formula 总被引:1,自引:0,他引:1
The equivalent inclusion method (EIM) is adopted to study the characteristics of the equivalent material properties of steel-fiber reinforced concrete as a function of the volume fraction and the length to diameter ratio of the fibers. It is found that the equivalent material moduli of concrete reinforce with randomly orientated and distributed fibers are insensitive to the length to diameter ratio of the steel fibers. A set of empirical formulae is then proposed for the purposes of engineering applications. The proposed empirical model can simplify the calculation of the equivalent material moduli. Verifications of the proposed empirical formulae with the EIM model and with experimental data are performed with two examples. The first is a compression test. The second is 4 point bending test. The empirical formulae, based on the equivalent inclusion method proposed in this study, represent an alternative means of quickly calculating the effective elastic modulus of steel-fiber reinforced concrete materials. 相似文献
110.
A full-field, three-dimensional (3D) computer model has been developed to numerically simulate reservoir compaction and surface subsidence for a weak, water-sensitive, hydrocarbon reservoir during field-wide water-injection operations. The developed model was used for modeling the compaction and subsidence processes under waterflood operations at the Ekofisk Field in the North Sea. The model was thoroughly validated through the comparison of model results to extensive field measurements with good agreement being achieved. The validated model has been successfully employed as a tool to forecast subsidence and to assist in the development of a subsidence risk assessment. For practical field applications, important quantitative information, that includes reservoir compaction, seafloor subsidence, and seafloor horizontal movement, may be generated from the full-field, 3D model and is presented in this paper. 相似文献