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81.
Lu C Chelikani S Jaffray DA Milosevic MF Staib LH Duncan JS 《IEEE transactions on medical imaging》2012,31(6):1213-1227
External beam radiation therapy (EBRT) for the treatment of cancer enables accurate placement of radiation dose on the cancerous region. However, the deformation of soft tissue during the course of treatment, such as in cervical cancer, presents significant challenges for the delineation of the target volume and other structures of interest. Furthermore, the presence and regression of pathologies such as tumors may violate registration constraints and cause registration errors. In this paper, automatic segmentation, nonrigid registration and tumor detection in cervical magnetic resonance (MR) data are addressed simultaneously using a unified Bayesian framework. The proposed novel method can generate a tumor probability map while progressively identifying the boundary of an organ of interest based on the achieved nonrigid transformation. The method is able to handle the challenges of significant tumor regression and its effect on surrounding tissues. The new method was compared to various currently existing algorithms on a set of 36 MR data from six patients, each patient has six T2-weighted MR cervical images. The results show that the proposed approach achieves an accuracy comparable to manual segmentation and it significantly outperforms the existing registration algorithms. In addition, the tumor detection result generated by the proposed method has a high agreement with manual delineation by a qualified clinician. 相似文献
82.
Searching the Web: general and scientific information access 总被引:4,自引:0,他引:4
The World Wide Web has revolutionized the way people access information, and has opened up new possibilities in areas such as digital libraries, general and scientific information dissemination and retrieval, education, commerce, entertainment, government and health care. There are many avenues for improvement of the Web; for example, in the areas of locating and organizing information. Current techniques for access to both general and scientific information on the Web provide much room for improvement; search engines do not provide comprehensive indices of the Web and have difficulty in accurately ranking the relevance of results. Scientific information on the Web is very disorganized. We discuss the effectiveness of Web search engines, including results showing that the major Web search engines cover only a fraction of the “publicly indexable Web”. Current research into improved searching of the Web is discussed, including new techniques for ranking the relevance of results, and new techniques in metasearch that can improve the efficiency and effectiveness of Web search. The creation of digital libraries incorporating autonomous citation indexing is discussed for improved access to scientific information on the Web 相似文献
83.
84.
Piyush Pathak Qiliang Yan Thomas Schmoeller Ebo Croffie Artak Isoyan Lawrence S. Melvin III 《Microelectronic Engineering》2009,86(4-6):500-504
Extreme ultraviolet lithography (EUVL) is a leading candidate for the 22 nm node lithography and beyond. However, there are still some critical problems before EUVL may be deployed in high-volume manufacturing. One of the critical problems is to estimate the EUVL aerial image formation for optical proximity correction (OPC) in order to compensate for EUVL effects such as shadowing and flare. This study discusses aerial image formation through modeling of optical transfer function to assimilate optical diffraction, long range layout dependent flare effects, and shadowing effects due to non-telecentric imaging optics in the EUV case. Hence, after optimizing optical process parameters to model the EUV aerial image, this study will investigate OPC modeling methods employed to compensate these optical effects in the mask design flow. 相似文献
85.
Krenz William Robin Michael Barez Shirin Stark Lawrence 《IEEE transactions on bio-medical engineering》1985,(10):817-825
A model of the pathways controlling the size of the human pupil is presented. Computer simulation of this model demonstrates the role played by each of the elements in the pupil pathways. Simulations of the effects of drugs and a few common abnormalities in the system also help to illustrate the workings of the internal processes. Computer models of this type can be used as teaching aids or as tools for testing of hypotheses regarding the system. 相似文献
86.
Potvin Alfred R. Crosier William G. Fromm Eli Lin James C. Neuman Michael R. Pilkington Theo C. Robinson Charles J. Schneider Lawrence W. Strohbehn John W. Szolovits Peter Tompkins Willis J. 《IEEE transactions on bio-medical engineering》1986,(1):48-59
MORE than 200 years ago, our forefathers made note of man's inalienable rights to life, liberty, and the pursuit of happiness. To the engineering community (applied science in the service of man), these may be coincident with applications to medicine and biology (biomedical engineering), defense, and entertainment. Biomedical engineering research has the distinction, among these three missions, of not only contributing to the quality of human life through the industrial economy but also to life itself?the most fundamental concern of all people. It is through biomedical engineering research that we have been able to learn much concerning the functioning of living systems, and it is through such knowledge that we have been able to develop improved clinical diagnosis, monitoring, and treatment, including life-sustaining devices and aids to the handicapped. Each step represents an improvement in the quality of life, and each step forms the foundation upon which to gain new knowledge to improve upon earlier developments. 相似文献
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88.
As a component of a multisensor approach to monitoring carbon sequestration sites for possible leaks of the CO? gas from underground reservoirs, a low-cost multispectral imaging system has been developed for indirect detection of gas leaks through observations of the resulting stress in overlying vegetation. The imager employs front-end optics designed to provide a full 50° field of view with a small, low-cost CMOS detector, while still maintaining quasi-collimated light through the angle-dependent interference filters used to define the spectral bands. Red and near-infrared vegetation reflectances are used to compute the normalized difference vegetation index (NDVI) and spatial and temporal patterns are analyzed statistically to identify regions of anomalous stress, which are then flagged for closer inspection with in-situ CO? sensors. The system is entirely self-contained with an onboard compact computer and is housed in a weather-proof housing to enable extended outdoor deployment. 相似文献
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90.
For the past several decades, pipeline incidents have resulted in highly publicized accounts of property damage, environmental harm, neighborhood destruction, serious injury, and death. 相似文献