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991.
One of the encoding methods offered by H.264 AVC is context-based adaptive variable length coding (CAVLC). This paper presents a high-throughput hardware implementation of the CAVLC encoder. A dual-coefficient scanning phase is investigated and modified to improve the speed of the encoding phase. This improved scanning solution determines all the required data for the encoding phase to be completed in a minimized and constant number of clock cycles. In addition, an algorithmic approach for encoding levels is exploited to reduce hardware resource requirements. The modified scanning phase approach offers significant throughput capabilities for CAVLC: at 200 MHz, the architecture is capable of encoding 1,080 p video files at 95 fps.  相似文献   
992.
Event sequence datasets with high event cardinality and long sequences are difficult to visualize and analyze. In particular, it is hard to generate a high level visual summary of paths and volume of flow. Existing approaches of mining and visualizing frequent sequential patterns look promising, but have limitations in terms of scalability, interpretability and utility. We propose CoreFlow, a technique that automatically extracts and visualizes branching patterns in event sequences. CoreFlow constructs a tree by recursively applying a three‐step procedure: rank events, divide sequences into groups, and trim sequences by the chosen event. The resulting tree contains key events as nodes, and links represent aggregated flows between key events. Based on CoreFlow, we have developed an interactive system for event sequence analysis. Our approach can compute branching patterns for millions of events in a few seconds, with improved interpretability of extracted patterns compared to previous work. We also present case studies of using the system in three different domains and discuss success and failure cases of applying CoreFlow to real‐world analytic problems. These case studies call forth future research on metrics and models to evaluate the quality of visual summaries of event sequences.  相似文献   
993.
Challenges of intervehicle ad hoc networks   总被引:4,自引:0,他引:4  
Intervehicle communication (IVC) networks, a subclass of mobile ad hoc networks (MANETs), have no fixed infrastructure and instead rely on the nodes themselves to provide network functionality. However, due to mobility constraints, driver behavior, and high mobility, IVC networks exhibit characteristics that are dramatically different from many generic MANETs. This paper elicits these differences through simulations and mathematical models and then explores the impact of the differences on the IVC communication architecture, including important security implications.  相似文献   
994.
995.
Advances in diagnostic assays for parasitic diseases include the use of monoclonal antibodies (MAbs) in antigen capture and competitive inhibition enzyme-linked immunosorbent assays (C-ELISA). Antigen capture ELISAs for Anaplasma marginale and Cryptosporidium parvum provide direct detection of these parasites during clinical disease, and the C-ELISA format has been adapted for detection of anti-Babesia equi, anti-A. marginale and anti-bluetongue virus antibodies. False-positive results may occur when antigen preparations in other ELISA formats are contaminated with Escherichia coli, erythrocyte or cell-culture antigens. The C-ELISA format overcomes problems of antigen purity, since the specificity of the C-ELISA depends solely on the MAb used. For this reason, the C-ELISA format is highly suited for use with recombinant antigens. Also, the use of recombinant protein in diagnostic assays precludes the need to infect animals for antigen production when the antigen cannot be produced in cell culture.  相似文献   
996.
997.
The present paper offers data to suggest an effect of geographic latitude in regard to the frequency of conception in human populations. The birth statistics from eight countries in different parts of the world have been evaluated. A particularly strong minimum appears to occur in almost all regions but is shifted in time with changing latitude.  相似文献   
998.
999.
PVC-211 murine leukemia virus (MuLV) is a neuropathogenic variant of Friend MuLV (F-MuLV). Previous studies from our laboratory demonstrated that unlike the parental F-MuLV, PVC-211 MuLV can infect rat brain capillary endothelial cells efficiently and that it has acquired genetic changes responsible for its expanded cellular tropism. To determine if PVC-211 MuLV also has expanded its host range, we tested its infectivity on Chinese hamster ovary-derived CHO-K1 cells, which are generally resistant to ecotropic MuLV. The results indicated that PVC-211 MuLV, but not F-MuLV, was highly infectious for CHO-K1 cells. Studies using glycosylation inhibitors and glycosylation mutants of CHO-K1 cells, as well as interference studies, suggested that PVC-211 MuLV has acquired the ability to interact with the ecotropic MuLV receptor on CHO-K1 cells that has undergone glycosylation-dependent modification. Using chimeric viruses between PVC-211 MuLV and F-MuLV, we were able to localize the viral genetic element crucial for CHO-K1 cell tropism within the env gene of PVC-211 MuLV and show that glycine at position 116 and lysine at position 129 of the envelope glycoprotein SU were important. These viral determinants also appear to confer tropism for other hamster cells resistant to ordinary ecotropic MuLVs. Further studies on the interaction between PVC-211 MuLV and the receptor on hamster cells may provide novel insights into the molecular mechanisms for receptor recognition and binding by viral envelope glycoproteins.  相似文献   
1000.
The purpose of this work is to improve the quality of patient care in radiation therapy by implementing a comprehensive quality assurance (QA) program aiming to enhance patient in vivo dosimetry on a routine basis. The characteristics of two commercially available semi-conductor diode dosimetry systems were evaluated. The diodes were calibrated relative to an ionization chamber-electrometer system with calibrations traceable to the National Institute of Standards and Technology (NIST). Correction factors of clinical relevance were quantified to convert the diode readings into patient dose. The results of dose measurements on 6 patients undergoing external beam radiation therapy for carcinoma of the prostate on three different therapy units are presented. Field shaping during treatments was accomplished either by multileaf collimation or by cerrobend blocking. A deviation of less than +/-4% between the measured and prescribed patient doses was observed. The results indicate that the diodes exhibit excellent linearity, dose reproducibility, minimal anisotropy, and can be used with confidence for patient dose verification. Furthermore, diodes render real time verification of dose delivered to patients.  相似文献   
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