51 research outputs found

    Objective Evaluation Criteria for Shooting Quality of Stereo Cameras over Short Distance

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    Stereo cameras are the basic tools used to obtain stereoscopic image pairs, which can lead to truly great image quality. However, some inappropriate shooting conditions may cause discomfort while viewing stereo images. It is therefore considerably necessary to establish the perceptual criteria that can be used to evaluate the shooting quality of stereo cameras. This article proposes objective quality evaluation criteria based on the characteristics of parallel and toed-in camera configurations. Considering the different internal structures and basic shooting principles, this paper focuses on short-distance shooting conditions and establishes assessment criteria for both parallel and toed-in camera configurations. Experimental results show that the proposed evaluation criteria can predict the visual perception of stereoscopic images and effectively evaluate stereoscopic image quality

    NOVEL NANOSTRUCTURED HIGH-PERFORMANCE ANION EXCHANGE IONOMERS FOR ANION EXCHANGE MEMBRANE FUEL CELLS

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    poster abstractA novel block copolymer, styrene-ethylene/butylene-styrene (SEBS), was chosen as the starting material to prepare pendant quaternary ammonium-based ionomers with an ion-exchange-capacity (IEC) of 0.66, 1.30, and 1.54 meq g-1, denoted by QSEBS-L, QSEBS-M, and QSEBS-H, respectively. These QSEBS ionomers were demonstrated to have excellent dimensional stability against hydration without significantly sacrificing the ionic conductivity as compared to the widely studied polysulfone (PSf) based ionomers. The water uptake of the QSEBS-based ionomers depended on their functionality; a higher IEC in the ionomer resulted in more water uptake and a higher ionic conductivity. The MEAs fabricated with the QSEBS-M and QSEBS-H ionomers showed the best H2/O2 fuel cell performance with peak power densities reaching 210 mW cm-2 at 50 °C, which was significantly higher than that of the PSf-based ionomers (~30 mW cm-2). Electrochemical impedance spec-troscopy (EIS) analysis indicated that the superior fuel cell performance ob-served with the QSEBS-based ionomers can be attributed to: (1) the low in-ternal cell resistance due to good comparability of the QSEBS-based ionomers with the membranes and (2) the low mass transport and charge transport in both the anode and the cathode due to the excellent dimension-al stability and balanced conductivity-hydrophobicity originated by the unique morphology of the QSEBS-based ionomers. AFM phase imaging measurements of the QSEBS-based ionomers revealed unique nanostruc-tures containing isolated hydrophobic and continuous anion conducting hy-drophilic domains. By further optimizing the chemistry and morphology of the ionomers and the membranes, the resistance of the anode and cathode of the AEMFCs will be further reduced

    A broadband polygonal cloak for acoustic wave designed with linear coordinate transformation

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    Previous acoustic cloaks designed with transformation acoustics always involve inhomogeneous material. In this paper, a design of acoustic polygonal cloak is proposed using linear polygonal transformation method. The designed acoustic polygonal cloak has homogeneous and anisotropic parameters, which is much easier to realize in practice. Furthermore, a possible acoustic metamaterial structure to realize the cloak is proposed. Simulation results on the real structure show that the metamaterial acoustic cloak is effective to reduce the scattering of the object.National Natural Science Foundation (China) (Grants 61322501, 61574127, and 61275183)Program for New Century Excellent Talents in University (China) (NCET-12-0489)Fundamental Research Funds for the Central Universities of ChinaZhejiang University. Innovation Joint Research Center for Cyber-Physical-Society SystemChina Postdoctoral Science FoundationUnited States. Office of Naval Research. Multidisciplinary University Research Initiative (Grant 2015M581930)Top-Notch Young Talents Program of Chin

    Objective evaluation criteria for stereo camera shooting quality under different shooting parameters and shooting distances

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    The vigorous development of 3D technology has improved the photography technology of stereo cameras constantly. However, there are no widely recognized objective evaluation criteria for stereo camera shooting quality under different shooting parameters and shooting distances. At the same time, no shooting guideline can be used for reference when people take stereoscopic images. To solve this problem, we propose the objective evaluation criteria of shooting quality of two types of stereo cameras (parallel and toed-in camera configurations) under three shooting conditions (macro shooting, short, and long distance shooting). In our work, several prominent evaluation factors are built by analyzing the characteristics of each shooting condition. Based on the effective five-point scale used in our subjective experiments, the relationships between shooting factors and shooting quality are obtained and then effectively integrated together to build the overall evaluation criteria. Finally, extensive experiments have been conducted, and the results demonstrate that the proposed approach can effectively evaluate the shooting quality of stereo cameras

    Preparation and analysis of sodium carboxymethyl cellulose and its effect on xerophthalmia

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    1348-1353carboxymethyl cellulose (CMC) has been effectively synthesized with high yield and purity. With the prolongation of time after model establishment, the values of Schirmer Ⅰ test (S Ⅰ t) and breakup time of tear film gradually decreased. The α-MSH and CMC alone could ameliorate corneal tissue damage and corneal morphological abnormalities in the dry eye to some extent. However, compared with monotherapy, the treatment of α-MSH combined with CMC has a more significant positive effect on the improvement of tear secretion and the stability of tear film in dry eye model in the early stage after modeling. There are significant differences between the model control group and the normal control group at each time point after model establishment (all Pth, 14th, 21th and 28th days after treatment. After 7, 14 and 21 days treatment, the S Ⅰ t values in the α-MSH+CMC treatment group were 4.80±0.79, 4.10±0.52 and 4.30±0.86 mm, respectively

    MICA/B expression is inhibited by unfolded protein response and associated with poor prognosis in human hepatocellular carcinoma

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    BackgroundMICA/B are major ligands for NK cell activating receptor NKG2D and previous studies showed that the serum level of soluble MICA (sMICA) is an independent prognostic factor for advanced human hepatocellular carcinoma. However, the correlation between cellular MICA/B expression pattern and human hepatocellular carcinoma progression has not been well explored. The unfolded protein response is one of the main causes of resistance to chemotherapy and radiotherapy in tumor cells. However, whether the UPR in HCC could regulate the expression levels of MICA/B and affect the sensitivity of HCC cells to NK cell cytolysis has not been established yet.MethodsMICA/B expression pattern was evaluated by immunohistochemistry and Kaplan-Meier survival analysis was done to explore the relationship between MICA/B expression level and patient survival. The protein and mRNA expression levels of MICA/B in SMMC7721 and HepG2 cells treated by tunicamycin were evaluated by flow cytometry, Western Blot and RT-PCR. The cytotoxicity analysis was performed with the CytoTox 96 Non-Radioactive LDH Cytotoxicity Assay.ResultsMICA/B was highly expressed in human hepatocellular carcinoma and the expression level was significantly and negatively associated with tumor-node metastasis (TNM) stages. Patients with low level of MICA/B expression showed a trend of shorter survival time. The unfolded protein response (UPR) downregulated the expression of MICA/B. This decreased protein expression occurred via post-transcriptional regulation and was associated with proteasomal degradation. Moreover, decreased expression level of MICA/B led to the attenuated sensitivity of human HCC to NK cell cytotoxicity.ConclusionThese new findings of the connection of MICA/B, UPR and NK cells may represent a new concrete theory of NK cell regulation in HCC, and suggest that targeting this novel NK cell-associated immune evasion pathway may be meaningful in treating patients with HCC.Electronic supplementary materialThe online version of this article (doi:10.1186/s13046-014-0076-7) contains supplementary material, which is available to authorized users

    Prediction of Arrival Flight Operation Strategies under Convective Weather Based on Trajectory Clustering

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    An airport’s terminal area is the bottleneck of the air transport system. Convective weather can seriously affect the normal flight status of arrival and departure flights. At present, pilots take different flight operation strategies to avoid convective weather based on onboard radar, visual information, adverse weather experience, etc. This paper studies trajectory clustering based on the OPTICS algorithm to obtain the arrival of typical flight routes in the terminal area. Based on weather information of the planned typical flight route and flight plan information, Random Forest (RF), K-nearest Neighbor KNN (KNN), and Support Vector Machines (SVM) algorithms were used for training and establishing the Arrival Flight Operation Strategy Prediction Model (AFOSPM). In this paper, case studies of historical arrival flights in the Guangzhou (ZGGG) and Wuhan (ZHHH) terminal area were carried out. The results show that trajectory clustering results based on the OPTICS algorithm can more accurately reflect the regular flight routes of arrival flights in a terminal area. Compared to KNN and SVM, the prediction accuracy of AFOSPM based on RF is better, reaching more than 88%. On this basis, six features—including 90% VIL, weather coverage, weather duration, planned route, max VIL, and planned Arrival Gate (AF)—were used as the input features for AFOSPM, which can effectively predict various arrival flight operation strategies. For the most frequently used arrival flight operation strategies under convective weather conditions—radar guidance, AF changing, and diversion strategy—the prediction accuracy of the ZGGG and ZHHH terminal areas can exceed 95%, 85%, and 80%, respectively
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