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61.
Lu Yang Tomohiro Yendo Mehrdad Panahpour Tehrani Toshiaki Fujii Masayuki Tanimoto 《Journal of Visual Communication and Image Representation》2010,21(5-6):542-560
In this paper, we present a new view synthesis method in multiview camera configurations of Free viewpoint TV (FTV) where potential depth errors are considered. The emphasis is on the artifacts eliminating for photorealistic synthesis especially near object boundaries. In contrast to conventional techniques which ignore geometry errors, we first categorize the artifact cases and depth modes. Furthermore, this paper infers the complementarity principle of the artifacts from left and right references. This complementarity guarantees the effectiveness of our reliability-based synthesis. The reliability reasoning is crucial for artifacts reduction. The reliable and unreliable areas from different views can be correctly labeled. Then artifacts caused by unreliable pixels from one reference can be replaced by the reliable pixels from the other reference. As a final result, artifacts of novel view are demonstrated to be significantly reduced on different multiview sequences. 相似文献
62.
Mahdi Bayrami Abolfazl Bayrami Aziz HabibiYangjeh Mohammad Saleh Shafeeyan Solmaz Feizpoor Farid Mohammadi Arvanagh Mohammad Reza Nourani Ramezan Ali Taheri 《IET nanobiotechnology / IET》2020,14(7):548
Wound healing has long been recognised as a major clinical challenge for which stablishing more effective wound therapies is necessary. The generation of metallic nanocomposites using biological compounds is emerging as a new promising strategy for this purpose. In this study, four metallic nanoparticles (NPs) with propolis extract (Ext) and one without propolis including ZnO/Ext, ZnO/Ag/Ext, ZnO/CuO/Ext, ZnO/Ag/CuO/Ext and ZnO/W were prepared by microwave method and assessed for their wound healing activity on excision experimental model of wounds in rats. The developed nanocomposites have been characterised by physico‐chemical methods such as X‐ray diffraction, scanning electron microscopy, diffuse reflectance UV–vis spectroscopy, Fourier transform infrared spectroscopy, thermogravimetric analysis and Brunauer–Emmett–Teller analyses. The wounded animals treated with the NPs/Ext in five groups for 18 days. Every 6 days, for measuring wound closure rate, three samples of each group were examined for histopathological analysis. The prepared tissue sections were investigated by haematoxylin and Eosin stainings for the formation of epidermis, dermis and muscular and Masson''s trichrome staining for the formation of collagen fibres. These findings toughly support the probability of using this new ZnO/Ag/Ext materials dressing for a wound care performance with significant effect compared to other NPs.Inspec keywords: nanomedicine, X‐ray diffraction, II‐VI semiconductors, visible spectra, ultraviolet spectra, nanocomposites, biomedical materials, proteins, wounds, nanoparticles, scanning electron microscopy, nanofabrication, skin, zinc compounds, silver, antibacterial activity, Fourier transform infrared spectra, copper compounds, molecular biophysicsOther keywords: propolis, wound healing applications, effective wound, metallic nanocomposites, biological compounds, metallic nanoparticles, microwave method, wound healing activity, physico‐chemical methods, Fourier transform infrared spectroscopy, diffuse reflectance UV‐vis spectroscopy, Brunauer‐Emmett‐Teller analyses, wounded animals, wound closure rate, wound care performance, histopathological analysis, scanning electron microscopy, X‐ray diffraction, thermogravimetric analysis, haematoxylin, Eosin stainings, Masson trichrome, epidermis, muscular trichrome, collagen fibres, time 18.0 d, time 6.0 d, ZnO‐CuO‐Ag 相似文献
63.
On the design of new ductile knee bracing 总被引:1,自引:0,他引:1
Mehrdad Lotfollahi 《Journal of Constructional Steel Research》2006,62(3):282-294
An approximate method is presented that can be used to determine the nonlinear behavior of a new structural bracing system called the ‘Chevron Knee Bracing’ (CKB). In this framing system, an especial form of diagonal brace connected to a knee element instead of a beam-column joint is investigated. The diagonal element provides lateral stiffness during a moderate earthquake. However, the knee element is designed to have three plastic joints or two yielded specimens in flexural and shear yielding mode, respectively, for dissipation of the energy caused by a strong earthquake. This article demonstrates the transformation of a complex problem into a new, practical set of design charts and graphs. To severe purpose, first, an optimal shape and angle for the diagonal-knee element is considered based on the studying of the elastic and inelastic behavior of the system. Then, by use of the main graphs and charts designed accordingly, the dynamic response of this model is properly investigated. Finally, the correctness of the results is ascertained, using example problems. The comparison of the results between the technique presented in this paper and the exact finite element methods and/or experimental results shows very good agreement and very suitable conformity. 相似文献
64.
Mehrdad Khamforoush Tahmasb Hatami Masome Mahjob Farzad Dabirian Ashkan Zandi 《Iranian Polymer Journal》2014,23(7):569-580
Modified rotating-jet electrospinning method (MRJM) is a new electrospinning technique with a novel setup including two metallic concentric hollow cylinders for generating highly aligned fibers. In this report, an experimental study was carried out to evaluate the effectiveness of MRJM for generating highly aligned nanofibers. For this purpose, the effect of voltage in the range of 10–22 kV, inner collector diameter in the range of 20–50 cm, and outer collector diameter in the range of 30–60 cm, on alignment degrees of electrospun fibers were explored and the results for each set of parameters were compared with those obtained for rotating-jet electrospinning method (RJM). The obtained results indicated that the alignment degrees of electrospun fibers in MRJM were significantly higher than those of RJM. The maximum achievable alignment degree in MRJM was around 82 % that was higher than the corresponding maximum value (40 %) of RJM. Although the effect of applied voltage on the degree of alignment in MRJM was observed to be negligible, it was experimentally proved that by manipulating the outer cylinder diameter, the degree of alignment can be increased up to 20 %. To achieve a conceptual understanding of the reason for significant influence of the outer cylinder on the elecrospinning performance, a formula was derived according to the Gauss’s law in the last part of this paper that relates the electric field strength inside the region between the inner cylinder and the spinneret to the radii of inner and outer cylinders. 相似文献
65.
Behrad Mahboobi Ehsan Soleimani-Nasab Mehrdad Ardebilipour 《Wireless Personal Communications》2014,77(3):1629-1658
In this paper, a new robust problem is proposed for relay beamforming in relay system with stochastic perturbation on channels of multi user and relay network. The robust problem aims to minimize the transmission power of relay nodes while the imperfect channel information (CSI) injects stochastic channel uncertainties to the parameters of optimization problem. In the power minimization framework, the relays amplification weights and phases are optimized assuming the availability of Gaussian channel distribution. The power sum of all relays is minimized while the outage probability of the instantaneous capacity (or SINR) at each link is above the outage capacity (or SINR) for each user. The robust problem is a nonconvex SDP problem with Rank constraint. Due to the nonconvexity of the original problem, three suboptimal problems are proposed. Simulation and numerical results are presented to compare the performance of the three proposed solutions with the existing worst case robust method. 相似文献
66.
Behrad Mahboobi Mostafa Mohammadkarimi Mehrdad Ardebilipour 《Wireless Personal Communications》2014,75(1):195-218
This paper investigates a new channel gain map tracking by Space-Time Extended Kalman Filtering (STEKF) for a flat channel, and a novel spectrum sensing via Time Spatial Weighted Non-negative Lasso (TSWNL) algorithm. STEKF enables CRs to estimate and interpolate channel gain map for the entire geographical area of interest with a limited number of CRs measurements. In order to sense primary users (PU) activities, include the transmission power by each PU, location and number of active PUs, TSWNL algorithm is proposed. Numerical results illustrate that the proposed STEKF channel estimation and TSWNL sensing algorithms outperforms linear methods. 相似文献
67.
The antimicrobial effects of ascorbic acid alone and in combination with lactic acid, against Escherichia coli O157:H7 in Brain Heart Infusion (BHI) broth and in carrot juice as a food model was investigated. In control samples, E. coli O157:H7 continued to growth from 3.98 ± 0.2 log CFU and reached to 8.88 ± 0.1 log10 CFU after 8 h at 37° C; however, bacterial population was undetectable level in BHI in the presence of 0.4% ascorbic acid and 0.2% lactic acid. In carrot juice, E. coli O157:H7 continue to grow from initial population count of 4.41 ± 0.9 log10 CFU to 8.75 ± 0.07 log10 CFU at 37 °C for 24 h. Similarly, the bacteria population was undetectable when 0.2 or 0.4% ascorbic acid and 0.2% lactic acid applied. Our findings suggest the application of ascorbic acid, in combination with lactic acid, may have potential as preservative to inhibit the growth of E. coli O157:H7 in food. 相似文献
68.
Patricio Toro Raúl Quijada Mehrdad Yazdani-Pedram José Luis Arias 《Materials Letters》2007,61(22):4347-4350
Chicken eggshell (ES) is an industrial byproduct containing 95% calcium carbonate, and its disposal constitutes a serious environmental hazard. Different proportions of chicken eggshell as bio-filler for polypropylene (PP) composite were compared with different particle sizes and proportions of commercial talc and calcium carbonate fillers by tensile test. The Young's modulus (E) was improved with the increment of ES content, and this bio-filler was better than all types of carbonate fillers with different particle sizes used in this study. Although ES composites showed lower E values than talc composites, talc filler could be replaced by up to 75% with ES while maintaining a similar stiffness and E compared to the talc composites. Scanning electron microscopy showed an improved interfacial bonding on the tensile fractured surface. The improvement in the mechanical properties was attributed to a better ES/matrix interface related to the geometric ratio of the ES particles similar to talc particles. 相似文献
69.
70.
A new method of direct inverter pulsewidth modulation (PWM) is described. In this technique the pulsewidths are determined by equating the incremental areas of the reference signal with the output pulse areas. This PWM method is compared to conventional methods, such as the natural PWM and the regular PWM, which are based on geometrical constructions. Harmonic analysis shows that the direct PWM method has less harmonic distortion that the other methods. Moreover, this technique is particularly suitable for microprocessor-based implementation since the pulsewidths are computable in real time from simple analytic expressions. It is shown that the output pulsewidths are directly proportional to the reference amplitude and inversely proportional to frequency. Therefore, constant volts/hertz operations and other modes of operation can be implemented very simply with a minimal storage requirement. 相似文献