206 research outputs found

    A throughput Fast Measurement Method for Two-Antenna Equipped Wireless MIMO Terminals

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    According to the Third Generation Partnership Project Specification, a Period of 8-12.8 H is Required to Evaluate the Multiple-Input-Multiple-Output (MIMO) Performance of a Wireless Terminal for a Single Frequency Point and Channel Model Combination. the Following Article Proposes a Semi-Simulation, Semi-Measurement-Based MIMO throughput Modeling Scheme Which Can Reduce the 8-12.8-H Measurement Time to 40-60 Min, Corresponding to More Than a Ten Times Improvement of the Test Efficiency, Without Loss of the Test Accuracy

    Wideband Inverse Matrix For Radiated Two-Stage MIMO Measurements

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    Multiple-input and multiple-output (MIMO) technology is one of the significant components in the growing fifth-generation (5G) communication systems. The 5G system has expanded its frequency range and widened the bandwidth to achieve higher throughput rates and more stable wireless qualities, which brings new challenges to the over-the-air (OTA) MIMO evaluations. The wide bandwidth introduces systematic uncertainties into the MIMO measurement because of the increased amplitude and phase variation issues under different frequencies in the wideband signals, and it could lead to invalid MIMO throughput measurement results when severe. The effect on antenna isolation resulting from amplitude and phase variation in wideband MIMO measurements are analyzed based on the RTS MIMO measurement method. A wideband inverse matrix algorithm is introduced to solve this issue and improve the wideband MIMO antenna isolation. The proposed method can be used in both MPAC and RTS chambers, which paves the way for decreasing the OTA measurement uncertainties on both 5G sub-6GHz wideband MIMO and millimeter-wave MIMO evaluations

    Graph-based Molecular Representation Learning

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    Molecular representation learning (MRL) is a key step to build the connection between machine learning and chemical science. In particular, it encodes molecules as numerical vectors preserving the molecular structures and features, on top of which the downstream tasks (e.g., property prediction) can be performed. Recently, MRL has achieved considerable progress, especially in methods based on deep molecular graph learning. In this survey, we systematically review these graph-based molecular representation techniques, especially the methods incorporating chemical domain knowledge. Specifically, we first introduce the features of 2D and 3D molecular graphs. Then we summarize and categorize MRL methods into three groups based on their input. Furthermore, we discuss some typical chemical applications supported by MRL. To facilitate studies in this fast-developing area, we also list the benchmarks and commonly used datasets in the paper. Finally, we share our thoughts on future research directions

    Integrated Optical Coherence Tomography and Optical Coherence Microscopy Imaging of Ex Vivo Human Renal Tissues

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    available in PMC 2012 June 04Materials and Methods A total of 35 renal specimens from 19 patients, consisting of 12 normal tissues and 23 tumors (16 clear cell renal cell carcinomas, 5 papillary renal cell carcinomas and 2 oncocytomas) were imaged ex vivo after surgical resection. Optical coherence tomography and optical coherence microscopy images were compared to corresponding hematoxylin and eosin histology to identify characteristic features of normal and pathological renal tissues. Three pathologists blinded to histology evaluated the sensitivity and specificity of optical coherence microscopy images to differentiate normal from neoplastic renal tissues. Results Optical coherence tomography and optical coherence microscopy images of normal kidney revealed architectural features, including glomeruli, convoluted tubules, collecting tubules and loops of Henle. Each method of imaging renal tumors clearly demonstrated morphological changes and decreased imaging depth. Optical coherence tomography and microscopy features matched well with the corresponding histology. Three observers achieved 88%, 100% and 100% sensitivity, and 100%, 88% and 100% specificity, respectively, when evaluating normal vs neoplastic specimens using optical coherence microscopy images with substantial interobserver agreement (κ = 0.82, p <0.01). Conclusions Integrated optical coherence tomography and optical coherence microscopy imaging provides coregistered, multiscale images of renal pathology in real time without exogenous contrast medium or histological processing. High sensitivity and specificity were achieved using optical coherence microscopy to differentiate normal from neoplastic renal tissues, suggesting possible applications for guiding renal mass biopsy or evaluating surgical margins.National Institutes of Health (U.S.) (NIH Grants R01-CA75289-14)National Institutes of Health (U.S.) (NIH R01-HL095717-02)United States. Air Force Office of Scientific Research (FA9550-10-1-0063)United States. Air Force Office of Scientific Research (FA9550-10-1-0551

    The Role of PKR/eIF2α Signaling Pathway in Prognosis of Non-Small Cell Lung Cancer

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    In this study, we investigated whether PKR protein expression is correlated with mRNA levels and also evaluated molecular biomarkers that are associated with PKR, such as phosphorylated PKR (p-PKR) and phosphorylated eIF2α (p-eIF2α).We determined the levels of PKR protein expression and mRNA in 36 fresh primary lung tumor tissues by using Western blot analysis and real-time reverse-transcriptase PCR (RT-PCR), respectively. We used tissue microarrays for immunohistochemical evaluation of the expression of p-PKR and p-eIF2α proteins. We demonstrated that PKR mRNA levels are significantly correlated with PKR protein levels (Spearman's rho = 0.55, p<0.001), suggesting that PKR protein levels in tumor samples are regulated by PKR mRNA. We also observed that the patients with high p-PKR or p-eIF2α expression had a significantly longer median survival than those with little or no p-PKR or p-eIF2α expression (p = 0.03 and p = 0.032, respectively). We further evaluated the prognostic effect of combined expression of p-PKR plus PKR and p-eIF2α plus PKR and found that both combinations were strong independent prognostic markers for overall patient survival on stage I and all stage patients.Our findings suggest that PKR protein expression may controlled by transcription level. Combined expression levels of PKR and p-PKR or p-eIF2α can be new markers for predicting the prognosis of patients with NSCLC

    An analysis of E-waste flows in China

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    In Europe, legislation about waste of electrical and electronic equipment (WEEE) recovery and recycling has been introduced in 2002, and corresponding legislation in the EU Member States was in place in August 2005 (EU-EC 2003). In the same period, China has been developing WEEE regulation as well. The main contribution to date to the Chinese legislative framework is the 'Circular Economy Promotion Law of the People's Republic of China' that was approved on August 29, 2008, and came into force as of January 1, 2009. Both these legislative systems contain the Extended Producer Responsibility as a core concept, as well as a formal, and, in the case of China, centralised, recovery system. Given the conceptual similarities of legislation on WEEE, but striking differences in the product recovery systems in China and the EU, it is of interest to investigate if the existing recovery and recycling system in China actually fits the new legislation. Currently, there is anecdotal evidence that, in China, much of the WEEE flows into informal recycling channels such as secondhand market and manual recycling workshops. Not much is known otherwise because a formal governance system and official statistics collection do not exist yet. More particularly, the actual WEEE flow in China, or in particular cities, is virtually unknown, as is the relationship between collection-treatment, re-selling and disposal. This paper suggests a Markov chain model that allows for the analysis of the flow of WEEE through the reverse chain from point of collection through the final disposal. We analyse this sytem in its equilibrium state and investigate the impact of scenarios that reflect key elements of the new WEEE regulation in China. In addition, we offer a qualitative analysis of the various scenarios for the three dimensions of sustainability: people, planet and profit. This research offers specific suggestions to strengthen the Chinese WEEE recovery and recycling system that would bring the actual system more in line with the current policy

    Photothermal optical coherence tomography in ex vivo human breast tissues using gold nanoshells

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    We demonstrate photothermal optical coherence tomography (OCT) imaging in highly scattering human breast tissue ex vivo. A 120 kHz axial scan rate, swept-source phase-sensitive OCT system at 1300 nm was used to detect phase changes induced by 830 nm photothermal excitation of gold nanoshells. Localized phase modulation was observed 300–600 μm deep in scattering tissue using an excitation power of only 22 mW at modulation frequencies up to 20 kHz. This technique enables integrated structural and molecular-targeted imaging for cancer markers using nanoshells.National Institutes of Health (U.S.) (Grant Number R01- CA75289-13)United States. Air Force Office of Scientific Research (Contract Number FA9550-07-1-0014)MFELP (Contract Number FA9550-07-1-0101)Natural Sciences and Engineering Research Council of Canada (NSERC) Heritage Scholarship FundCenter for Integration of Medicine and Innovative TechnologyNational Science council of Taiwan. Taiwan Merit Scholarshi
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