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41.
The paper presents a novel blind watermarking scheme for image copyright protection, which is developed in the discrete wavelet transform (DWT) and is based on the singular value decomposition (SVD) and the support vector regression (SVR). Its embedding algorithm hides a watermark bit in the low–low (LL) subband of a target non-overlap block of the host image by modifying a coefficient of U component on SVD version of the block. A blind watermark-extraction is designed using a trained SVR to estimate original coefficients. Subsequently, the watermark bit can be computed using the watermarked coefficient and its corresponding estimate coefficient. Additionally, the particle swarm optimization (PSO) is further utilized to optimize the proposed scheme. Experimental results show the proposed scheme possesses significant improvements in both transparency and robustness, and is superior to existing methods under consideration here. 相似文献
42.
Chun-Yuan Cheng Lassina Barro Shang-Ting Tsai Tai-Wei Feng Xiao-Yu Wu Che-Wei Chao Ruei-Siang Yu Ting-Yu Chin Ming Fa Hsieh 《International journal of molecular sciences》2021,22(6)
Microglia-mediated neuroinflammation is recognized to mainly contribute to the progression of neurodegenerative diseases. Epigallocatechin-3-gallate (EGCG), known as a natural antioxidant in green tea, can inhibit microglia-mediated inflammation and protect neurons but has disadvantages such as high instability and low bioavailability. We developed an EGCG liposomal formulation to improve its bioavailability and evaluated the neuroprotective activity in in vitro and in vivo neuroinflammation models. EGCG-loaded liposomes have been prepared from phosphatidylcholine (PC) or phosphatidylserine (PS) coated with or without vitamin E (VE) by hydration and membrane extrusion method. The anti-inflammatory effect has been evaluated against lipopolysaccharide (LPS)-induced BV-2 microglial cells activation and the inflammation in the substantia nigra of Sprague Dawley rats. In the cellular inflammation model, murine BV-2 microglial cells changed their morphology from normal spheroid to activated spindle shape after 24 h of induction of LPS. In the in vitro free radical 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay, EGCG scavenged 80% of DPPH within 3 min. EGCG-loaded liposomes could be phagocytized by BV-2 cells after 1 h of cell culture from cell uptake experiments. EGCG-loaded liposomes improved the production of BV-2 microglia-derived nitric oxide and TNF-α following LPS. In the in vivo Parkinsonian syndrome rat model, simultaneous intra-nigral injection of EGCG-loaded liposomes attenuated LPS-induced pro-inflammatory cytokines and restored motor impairment. We demonstrated that EGCG-loaded liposomes exert a neuroprotective effect by modulating microglia activation. EGCG extracted from green tea and loaded liposomes could be a valuable candidate for disease-modifying therapy for Parkinson’s disease (PD). 相似文献
43.
The mechanical properties and post-thermal aging properties of natural rubber (NR) and polybutadiene rubber (BR) blends at
different blending ratios are investigated herein. The experimental results show that both tensile and tear strengths of NR/BR
blends increase with increasing NR content. BR has a higher compression stiffness than NR. The deformation of BR is less than
that of NR under the same load conditions. With regard to aging properties, both tensile stress and strain of NR/BR blends
decrease after prolonged aging. In addition, the stress loss of BR is lower than that of NR, meaning that the aging resistance
property of BR is superior to that of NR. Furthermore, accumulated thermal history has shifted the glass transition temperature
(T
g) of NR/BR blends toward lower temperatures while the loss tangent (tan δ) value increases with prolonged thermal aging. 相似文献
44.
Jian-Ruei Chen Paul C.-P. Chao Che-Hung Tsai Wei-Dar Chen 《Microsystem Technologies》2014,20(8-9):1583-1595
A new image acquisition system module for extracting signals of high-resolution short wave infrared (SWIR) from a focal plane array (FPA) is presented in this study. The short wave infrared (SWIR—with wavelength about 900–1,700 nm) images have been proven its unique values in many applications such as military, semiconductor inspection and aviation security. The designs for the SWIR data acquisition system module consists of digitization and acquisition of FPA signals, design of synchronous dynamic random access memory controller and real-time image signal transformation and display. Three major steps involved towards a successful SWIR module—(1) Selection of hardware ICs according to specification for the FPA; (2) Design of a timing generator for the image acquisition system to control FPA and other ICs by Verilog HDL programming; (3) Integrate the individual modules on a PCB. The SWIR image output signals are successfully generated in the format of National Television System Committee (NSTC), which can be displayed on a common NTSC monitor, flat panel displays with an AV input terminal or a CRT display in a favorable speed of frame rate at 30 per second. 相似文献
45.
This study establishes a bi-objective imperfect preventive maintenance (BOIPM) model of a series-parallel system. The improvement factor method is used to evaluate the extent to which repairing components can restore the system reliability. The total maintenance cost and mean system reliability are optimized simultaneously through determining the most appropriate maintenance alternative. A bi-objective hybrid genetic algorithm (BOHGA) is established to optimize the BOIPM model. The BOHGA utilizes a Pareto-based technique to determine and retain the superior chromosomes as the GA chromosome evolutions are performed. Additionally, a unit-cost cumulative reliability expectation measure (UCCREM) is developed to evaluate the extent to which maintaining each individual component benefits the total maintenance cost and system reliability over the operational lifetime. This UCCREM is then incorporated into the genetic algorithm to construct a superior initial chromosome population and thereby enhance its solution efficiency. In order to obtain diverse bi-objective solutions as the Pareto-efficient frontier is approached, the closeness metric and diversity metric are employed to evaluate the superiority of the non-dominated solutions. Accordingly, decision makers can easily determine the most appropriate maintenance alternative. Three simulated cases verify the efficacy and practicality of this approach for determining an imperfect preventive maintenance strategy. 相似文献
46.
Hong-Bing Tsai Da-Kong Lee Jung-Liang Liu Jiang-Wen You 《Journal of Polymer Research》1995,2(2):109-114
The block copolyetheresters with hard segments of poly(pentamethylene p,p-bibenzoate) and soft segments of poly (tetramethylene ether) were prepared by melt polycondensation of dimethyl-p,p-bibenzoate, 1,5-pentanediol and poly (tetramethyene ether) glycol (PTMEG) with molecular weights of 650, 1000 and 2000. The results by NMR indicate that the polymer composition is determined by the charge molar ratio (x) of PTMEG to dimethyl-p,p-bibenzoate. The thermal transitions of the block copolyetheresters were investigated by DSC in combination with X-ray diffraction and polarized microscopy. Some block copolyetheresters exhibit a monotropic smectic phase due to the presence of the poly (pentamethylene p,p-bibenzoate) segments. As the molar content of PTMEG increases, the average sequence length of the polyester segments decreases, the isotropic-smectic transition temperature and the smectic order decrease accordingly. When x is as high as 0.3, the block copolyetheresters exhibit no liquid crystallinity. 相似文献
47.
Fey-long Wang Tan-feng Tsai Li-ching Yu In-zu Hu Yao-pin Yen 《Catalysis Letters》1996,42(3-4):155-160
The methylation of various aldehydes, such as acetaldehyde, propionaldehyde, and phenylacetaldehyde over titanium oxidesupported vanadium oxide was studied under atmospheric pressure and temperatures of 250–400°C. The catalyst properties of titanium oxide can be enhanced only by addition of a fairly small amount of vanadium. High-temperature treatment transforms titanium oxide, the support, from anatase to rutile, which causes the catalysts to lose their catalytic properties. The reactivity of these can be ranked in the following order: acetaldehyde > propionaldehyde > phenylacetaldehyde. The steric effect of the substituted groups in propionaldehyde or phenylacetaldehyde may prevent self-condensation to form oligomers and to give a high selectivity of alkylated products. 相似文献
48.
Ming‐Jen Chang Jen‐Yun Tsai Chia‐Wei Chang Hwai‐Ming Chang George J. Jiang 《应用聚合物科学杂志》2007,103(6):3680-3687
Well‐defined polymer‐Mg(OH)2 nanocomposites were prepared by atom transfer radical polymerization (ATRP). The ATRP initiators were covalently attached to the Mg(OH)2 by esterification of 2‐chloropropionyl chloride with hydroxyl group. The amount of polymer grafted from Mg(OH)2 can be controlled using a different catalyst system and adding a small amount of polar solvent. The well‐defined diblock copolymer, consisting of poly(styrene) (PS) and poly(methyl methacrylate) (PMMA) were synthesized. The products were characterized by nuclear magnetic resonance, Fourier transform infrared, differential scanning calorimetry, and thermal gravimetric analysis. The morphologies of PS/PMMA and PS/PMMA/Mg(OH)2‐g‐PS‐b‐PMMA blends are compared by using a scanning electron microscope. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 3680–3687, 2007 相似文献
49.
Tseng-Chang Tsai Wenent P. Pan Li-Jen Leu Shih-Tsung Yu 《Chemical Engineering Communications》1989,78(1):97-109
Based on the correlations between laboratory units and commercial plants, a procedure has been developed to guide commercial FCC (Fluid Catalytic Cracking) catalysts selection. Examining the operability of catalyst mixtures during catalyst transition period is emphasized. The testing procedure is simple and reliable. A commercially available catalyst and the catalyst currently in use have been compared to demonstrate the applicability of this procedure. The commercial testing has confirmed the reliability of laboratory results. The use of the catalyst evaluated led to a 30% saving in catalyst cost. 相似文献
50.
Callus cultures ofTheobroma cacao L., initiated from explants of immature cocoa bean cotyledons, contained 5.3%–6.4% lipids (dry wt basis). The major fatty
acids were palmitic, oleic and linoleic acids. Cell suspensions contained 5.7–7.7% total lipids which had a higher polyunsaturated
fatty acid content than total lipids of the calli. Phospholipids and glycolipids were the predominant lipid classes of calli
and cell suspensions. Immature cocoa beans at early stages of development contained much higher polyunsaturated fatty acids,
higher polar lipids and lower triglycerides than did mature ripe beans. Ripe cocoa beans contained 54% total lipids of which
96.8% where triglycerides. The fatty acid composition of total lipids of calli and cell suspensions were similar to those
of the immature cocoa beans. 相似文献