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排序方式: 共有157条查询结果,搜索用时 15 毫秒
81.
In this paper, on the base of the Ishikawa iteration method and the hybrid method in mathematical programming, we give two new strong convergence methods for finding a point in the common fixed point set of a nonexpansive semigroup in Hilbert space.  相似文献   
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83.
Abstract

Developed at National Chiao Tung University, TAIWAN iTS‐1 is the first smart car with active safety systems and comfortable autonomous driving in Taiwan. An adaptive vision‐based lane detection algorithm was proposed to help the lateral control unit to keep the car in its lane safely. It also carries a DSP system to generate warning signals for unintentional roadway departures. A laser radar measures the distance between the preceding car and TAIWAN iTS‐1. With this information, the longitudinal control unit performs intelligent cruise control and stop‐and‐go functions. The remote control function is realized on TAIWAN iTS‐1 for safety testing and military applications. Unlike most smart car studies, this paper considers not only driving safety demands but also non‐driving security. An active mobile surveillance system will inform the car owner when the car is illegally broken into, anytime and anywhere. For drivers and passengers, the perception of comfort is achieved by intelligent vehicle dynamic control. All functions integrated into TAIWAN iTS‐1 have been tested repeatedly on National Highway 3 and Expressway 68 in the Hsinchu area and the system's robustness has been successfully demonstrated in these real‐road experiments.  相似文献   
84.
Magnetic nanoparticles [MNPs] made from iron oxides have many applications in biomedicine. Full understanding of the interactions between MNPs and mammalian cells is a critical issue for their applications. In this study, MNPs were coated with poly(ethylenimine) [MNP-PEI] and poly(ethylene glycol) [MNP-PEI-PEG] to provide a subtle difference in their surface charge and their cytotoxicity which were analysed by three standard cell viability assays: 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium [MTS], CellTiter-Blue and CellTiter-Glo (Promega, Southampton, UK) in SH-SY5Y and RAW 264.7 cells The data were validated by traditional trypan blue exclusion. In comparison to trypan blue manual counting, the MTS and Titer-Blue assays appeared to have consistently overestimated the viability. The Titer-Glo also experienced a small overestimation. We hypothesise that interactions were occurring between the assay systems and the nanoparticles, resulting in incorrect cell viability evaluation. To further understand the cytotoxic effect of the nanoparticles on these cells, reactive oxygen species production, lipid peroxidation and cell membrane integrity were investigated. After pegylation, the MNP-PEI-PEG possessed a lower positive surface charge and exhibited much improved biocompatibility compared to MNP-PEI, as demonstrated not only by a higher cell viability, but also by a markedly reduced oxidative stress and cell membrane damage. These findings highlight the importance of assay selection and of dissection of different cellular responses in in-vitro characterisation of nanostructures.  相似文献   
85.
In this work, biodegradable composites from poly(lactic acid) (PLA) and oil palm empty fruit bunch (OPEFB) fiber were prepared by melt blending method. Prior to mixing, the fiber was modified through bleaching treatment using hydrogen peroxide. Bleached fiber composite showed an improvement in mechanical properties as compared to untreated fiber composite due to the enhanced fiber/matrix interfacial adhesion. Interestingly, fiber bleaching treatment also improved the physical appearance of the composite. The study was extended by blending the composites with commercially available masterbatch colorant.  相似文献   
86.
Clean Technologies and Environmental Policy - Asia currently faces a serious crisis involving plastic wastes. Efforts to curb plastic waste in the region are mostly hampered by inadequate recycling...  相似文献   
87.
In this paper, superheated steam (SHS) was used as cost effective and green processing technique to modify oil palm mesocarp fiber (OPMF) for biocomposite applications. The purpose of this modification was to promote the adhesion between fiber and thermoplastic. The modification was carried out in a SHS oven at various temperature (200–230 °C) and time (30–120 min) under normal atmospheric pressure. The biocomposites from SHS-treated OPMFs and poly(butylene succinate) (PBS) at a weight ratio of 70:30 were prepared by melt blending technique. The mechanical properties and dimensional stability of the biocomposites were evaluated. This study showed that the SHS treatment increased the roughness of the fiber surface due to the removal of surface impurities and hemicellulose. The tensile, flexural and impact properties, as well as dimensional stability of the biocomposites were markedly enhanced by the presence of SHS-treated OPMF. Scanning electron microscopy analysis showed improvement of interfacial adhesion between PBS and SHS-treated OPMF. This work demonstrated that SHS could be used as an eco-friendly and sustainable processing method for modification of OPMF in biocomposite fabrication.  相似文献   
88.
Heterogeneous network (HetNet) is one of the most promising approaches of IMT Advanced, which not only offers higher capacity and data rate, but also network Energy Efficiency (EE). HetNet is an advanced network that promotes complex cooperation between multiple tiers or sizes of base stations, i.e. macro, micro, pico, and femto base stations towards the above benefits. In this paper, a theoretical model for evaluating the EE of HetNet is proposed. Then, a sleep mode mechanism on picocells is proposed to reduce the total energy consumption which subsequently improves the EE. Simulation results show that EE can be increased by balancing the traffic load between different types of base stations. In fact, the improvement very much depends on the percentage of traffic that is offloaded to picocells. At low to medium traffic load conditions, significant improvements in EE can be observed through the proposed sleep mechanism. It is observed that by combining the sleep mode feature of picocells and load balancing between the different types of base stations in HetNet, further EE improvements up to 68 % for low traffic load and up to 33 % for medium traffic load can be achieved.  相似文献   
89.
Positron emission tomography (PET) with 2-[F-18]-fluoro-2-deoxy-D-glucose (FDG) can demonstrate the glucose metabolism characteristics of a lesion, which may be helpful in differentiating between benign and malignant focal pulmonary lesions. Malignant cells demonstrate higher glucose metabolic activity than benign lesions. However, some inflammatory processes also show significant FDG uptake. We present two cases where high FDG uptake was found in inflammatory lesions in the lungs. The first case was that of a 38-year-old woman with chronic cough for more than 20 years. FDG PET revealed a hypermetabolic lesion with a lesion-to-background ratio of 8.0 at the posterior aspect of the right middle lung. She underwent thoracotomy and tumor resection, and was diagnosed with cryptococcosis. The second case was that of a 72-year-old woman who had pulmonary tuberculosis previously with cavitation in the left lower lobe. She suffered from fever, chills and severe hemoptysis for several days before this admission. FDG PET revealed a hypermetabolic ring at the periphery of the cavity. The lesion-to-background ratio was 7.8. Echo-guided biopsy showed no evidence of malignancy. She was treated with antibiotics and the symptoms subsided gradually. Lung abscess complicating a pre-existing cavity was diagnosed. These two cases substantiate that positive FDG PET results should be interpreted with caution in differentiating benign from malignant pulmonary abnormalities, especially in regions with a high prevalence of granulomatous lesions.  相似文献   
90.
An experimental study of heat transfer in a radially rotating trapezoidal duct with two bevel walls roughened by deepened scales is performed with cooling applications to gas turbine rotor blades. Laboratory scale heat transfer data along the centerlines of two scale-roughened walls is generated within the parametric ranges of 7500 ? Re ? 15,000, 0 ? Ro ? 1.8 and 0.13 ? Δρ/ρ ? 0.42. No previous study has examined the heat transfer in a rotating scale-roughened channel and the present Ro range extends considerably from other researches to date. A selection of experimental data illustrates the individual and interactive impacts of Re, Ro and buoyancy number (Bu) on local heat transfer through which the manners of isolated and synergetic influences of Coriolis force and rotating buoyancy on heat transfer are examined. Local Nusselt number ratios between rotating and static channels on the stable (leading) and unstable (trailing) scale-roughened surfaces with Ro varying from 0.1 to 1.8 fall in the ranges of 0.8–2 and 1.1–2.5, respectively. Rotating buoyancy effects are weakened as Ro increases that impair local heat transfer for the present test configurations. Empirical heat transfer correlations for developed flow regions on two scale-roughened surfaces are derived that permit the evaluation of interactive and individual effects of Re, Ro and Bu on local heat transfer.  相似文献   
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