26 research outputs found

    Multi-lingual Common Semantic Space Construction via Cluster-consistent Word Embedding

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    We construct a multilingual common semantic space based on distributional semantics, where words from multiple languages are projected into a shared space to enable knowledge and resource transfer across languages. Beyond word alignment, we introduce multiple cluster-level alignments and enforce the word clusters to be consistently distributed across multiple languages. We exploit three signals for clustering: (1) neighbor words in the monolingual word embedding space; (2) character-level information; and (3) linguistic properties (e.g., apposition, locative suffix) derived from linguistic structure knowledge bases available for thousands of languages. We introduce a new cluster-consistent correlational neural network to construct the common semantic space by aligning words as well as clusters. Intrinsic evaluation on monolingual and multilingual QVEC tasks shows our approach achieves significantly higher correlation with linguistic features than state-of-the-art multi-lingual embedding learning methods do. Using low-resource language name tagging as a case study for extrinsic evaluation, our approach achieves up to 24.5\% absolute F-score gain over the state of the art.Comment: 10 page

    Thermodynamic Cycle Analysis and Experimental Investigate on a Two-stage Vapor Injection Low Temperature Air Source Heat Pump with a Variable Displacement Ratio Rotary Compressor

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    Two-stage vapor injection compression cycle with flash tank was thermodynamically analyzed, the results showed that there existed the optimum theoretical displacement ratio of high stage to low stage corresponding to the maximum coefficient of performance(COP), the optimum displacement ratio and the volumetric heating capacity decreased with evaporation temperature decreasing. An optimum theoretical displacement ratio correlation for R290, R32 and R410A was given. A new type two-stage vapor injection low temperature air source heat pump (ASHP) was designed, which had a variable speed triple-cylinder rotary compressor with two cylinders in low stage and one cylinder in high stage. The experimental results of the new type ASHP showed that the heating capacity under 20℃/-20℃(inside room /outside room) could reach the rated heating capacity under 20℃/7℃, improving 96% compared to conventional one-stage ASHP, the heating capacity under 20℃/-30℃ could reach 80% of the rated one. COP of the new type ASHP could improve 5%~10% when the heating capacity was comparable to the conventional ASHP, and the heating capacity of the new type ASHP could improve 30%~50% when COP was comparable to the conventional ASHP

    SARS-associated Coronavirus Transmitted from Human to Pig

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    Severe acute respiratory syndrome–associatedcoronavirus (SARS-CoV) was isolated from a pig during a survey for possible routes of viral transmission after a SARS epidemic. Sequence and epidemiology analyses suggested that the pig was infected by a SARS-CoV of human origin

    Using GVF snake to segment liver from CT images

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    Conference Name:IEEE/EMBS International Summer School on Medical Devices and Biosensors. Conference Address: Cambridge, MA. Time:SEP 04-06, 2006.Liver segmentation on computed tomography (CT) images is a challenging task because the images are often corrupted by noise and sampling artifacts. Thus we choose GVF snake to perform the task. Unfortunately, GVF snake use Gaussian function to generate the edge map. We rind that this often cause new problems such as blur the liver boundary. To avoid this, a Canny edge detector is a good choice. Another problem during the segmentation is that GVF snake cannot works well with bad initialization, especially when encounter deep concavities. Fortunately we rind that if the initial contour can cross the "bottleneck" of the deep concave, it can easily reach the boundary of liver. Thus an algorithm was developed to generate the initial contour automatically. We introduce a new "maximum force angle map" to evaluate the direction variability of the GVF forces. This map can mark up the "bottleneck" and give a trace to run through it. There may be other trace we do not need in the map. With the help of transcendental knowledge about the liver, such as the position, the shape and the Hounsfield unit range of the liver, the correct trace can be found. The contour of this trace is suitable or using as initial contour for GVF snake. By this means e finally segment the liver slice by slice correctly

    Adaptive Voltage Control of Distribution Network with High Proportion PV

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    With the increase of grid-connected PV capacity, voltage regulation at point of common coupling by controlling the reactive power injected into the grid is available. This paper presents an adaptive voltage control strategy for distribution network with high proportion PV system. The PI gain of the voltage controller is automatically adjusted by the extremum seeking algorithm to dynamically respond to the changes of the network. The PI gains are updated online through the minimization of a cost function, which represents the voltage controller performance. Finally, a distribution network model of 5 MW photovoltaic power generation system is built in MATLAB / Simulink to verify the effectiveness of the proposed control strategy

    A Study on the Adaptability of Nonhydrocarbon Gas-Assisted Steam Flooding to the Development of Heavy Oil Reservoirs

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    In view of the serious heat loss in the process of steam injection for heavy oil recovery, nonhydrocarbon gas combined with steam has attracted much attention in recent years to realize the efficient development of heavy oil. Due to the wide variety of nonhydrocarbon gases, their performance in pressurization, dissolution, viscosity reduction, and heat loss decrease is changeable. In this paper, four groups of one-dimensional physical simulation experiments on different nonhydrocarbon gas-assisted steam flooding methods were carried out, and the effect on oil displacement characteristics under high temperature and pressure conditions was studied. Moreover, the differences in N2, CO2, and flue gas in energy supplementation, heat transfer, and oil recovery efficiency were also analyzed. The results showed that the three nonhydrocarbon gas-assisted steam flooding methods could significantly improve the oil displacement efficiency, which was specifically embodied as a faster oil production rate and longer production period. Compared with pure steam flooding, the recovery was increased by 12.13%, 16.71% and 13.01%, respectively. The effects of N2 in energy supplementation and heat transfer reinforcement were the greatest among the three nonhydrocarbon gases, followed by those of flue gas, and the CO2 effects were the worst. The temperature at the end of the sandpack model increased by 14.3 °C, 8.8 °C and 13.1 °C, respectively. In addition, CO2-assisted steam flooding had a prominent oil recovery effect, and the oil content of the sands in the front and middle of the model was significantly lower than that of other displacement methods. Most importantly, combined with the analysis of the remaining oil in the oil sands after displacement, we explained the contrasting contradictions of the three non-hydrocarbon gases in terms of recovery and energy supply/heat transfer, and further confirmed the gas properties and reservoir adaptability of the three non-hydrocarbon gases. The results may provide a theoretical basis for the selection of nonhydrocarbon gases for heavy oil reservoirs with different production requirements

    Automatic liver segmentation from CT images using adaptive fast marching method

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    Conference Name:2013 7th International Conference on Image and Graphics, ICIG 2013. Conference Address: Qingdao, Shandong, China. Time:July 26, 2013 - July 28, 2013.Liver segmentation is the fundamental step in computer-aided liver disease diagnosis and surgery planning. In this study, we developed a fully automatic liver extraction scheme based on an adaptive fast marching method (FMM). Firstly, a thresholding operation was applied to remove the ribs, spines and kidneys. Followed by a smooth filter for noise reduction. Secondly, a nonlinear gray scale converter was used to enhance the contrast of the liver parenchyma. The enhanced image is then eroded with 3-voxel radius so that small regions are deleted. The seed points located in the liver were selected automatically. Finally, using the processed image as a speed function, FMM was employed to generate the liver contour. Clinical validation has performed on 30 abdominal computed tomography (CT) datasets. The proposed algorithm achieved an overall true positive rate (TPR) of 0.98. It takes about 0.30 s for a 512×512-pixel slice. The method has been applied successfully for fast and accurate liver segmentation. ? 2013 IEEE

    Computer-aided Preoperative Planning for liver Surgery based on CT Images

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    Conference Name:International Conference on Advances in Engineering (ICAE). Conference Address: Nanjing, PEOPLES R CHINA. Time:DEC 17-18, 2011.In this study, we present a computer-aided preoperative planning system (Liver 2.0) for liver surgery based on CT images. The proposed system is composed of two main sections: image analysis and treatment planning. The first module provides effective image analysis algorithms and three-dimensional (3D) visualization of all relevant anatomic and pathologic structures. The later module provides the resection tools and measurement tools for virtual liver surgery planning. The surgeon can flexibly specify resection regions with resection tools, which can be applied selectively to different structures, and obtain the quantitative analysis of distance, area, volume and angle with measurement instruments. The results of clinical trial indicate that the virtual liver resections provide a reasonable and useful basis for preoperative planning, and it also can be used for educational purposes. (C) 2011 Published by Elsevier Ltd. Selection and/or peer-review under responsibility of ICAE2011
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