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11.
This paper proposes an effective higher order statistics method to address subpixel image registration. Conventional power spectrum-based techniques employ second-order statistics to estimate subpixel translation between two images. They are, however, susceptible to noise, thereby leading to significant performance deterioration in low signal-to-noise ratio environments or in the presence of cross-correlated channel noise. In view of this, we propose a bispectrum-based approach to alleviate this difficulty. The new method utilizes the characteristics of bispectrum to suppress Gaussian noise. It develops a phase relationship between the image pair and estimates the subpixel translation by solving a set of nonlinear equations. Experimental results show that the proposed technique provides performance improvement over conventional power-spectrum-based methods under different noise levels and conditions.  相似文献   
12.
Subband Synthesis for Color Filter Array Demosaicking   总被引:1,自引:0,他引:1  
This paper presents a new algorithm for demosaicking images captured through a color filter array (CFA). The objective of the CFA demosaicking is to render a full color image from the mosaicked image. This is commonly achieved by estimating the missing color information from the surrounding observed pixels. In this paper, we integrate the observation that color images have a strong intrachannel spatial correlation in low-frequency components and a dominant interchannel correlation in the high- frequency components. A new framework is proposed to utilize this information where the missing pixels in each color channel are estimated from the wavelet subbands. A modified median-filtering operation is then applied in the subband domain. The algorithm is adaptive and produces superior full-resolution images when compared with other methods.  相似文献   
13.
Treatment of lead-contaminated material focuses on the reduction of leached lead concentrations in laboratory leaching tests. There has been little study on the chemical stability of treated materials after waste disposal. To investigate the effects of weathering on several solidification/stabilization chemistries, lead-contaminated soil was treated with various agents (cement, phosphates, dithiocarbamate, calcium hydroxide, calcium carbonate, and metallic iron) and subjected to natural weathering for one year. Lead concentrations and pH values in field percolates and leachates from toxicity characteristic leaching procedure (TCLP) and water leaching tests were used to evaluate changes in the treatment effectiveness. Weathering altered the treatment chemistry of several additives—alkaline additives were neutralized, while reduced additives were oxidized. Lead concentrations in field percolates from the untreated soil were around 1.0?mg/L, and did not vary over one year of weathering time. After one year of weathering, lead concentrations in field percolates from most samples were reduced to low levels (<0.15 mg/L). Weathering also affected lead concentrations in the TCLP and water leach test leachates from the treated wastes. Treated wastes in which the alkaline additives were neutralized or reduced additives oxidized gave higher TCLP lead concentrations after weathering than before, in contrast to the decreasing lead concentrations in the field percolates. Water leaching tests on the alkaline treated wastes had lower lead concentrations after weathering than before.  相似文献   
14.
使用天然制冷剂的制冷系统在全世界范围内受到了越来越多的关注。CO2(R744)制冷剂重新兴起,它无毒、不可燃,并且作为工业生产过程中的副产品而被广泛应用。然而,CO2系统的工作压力要比其它使用诸如HCFC、HFC、HFC混合制冷剂的系统高得多。因此,有必要开发可在这种高压下高效、可靠运行的压缩机。一种适应这一要求的双级全封闭式滚动活塞压缩机现已研发成功。其外径尺寸为207.8mm、高445.8mm、容积为21.8cc。在第一级中,吸入气体被压缩到7~8MPa;在第二级中,气体被压缩至11~12MPa。在压缩机的研发过程中,机壳、轴承和曲轴的设计为其关键因素。  相似文献   
15.
Mice pretreated with Zn have increased renal metallothionein (MT) levels and are protected from CdMT nephrotoxicity. To determine whether MT is important in this Zn-induced protection against CdMT-induced nephrotoxicity, MT-transgenic mice that have high levels of MT in their kidneys (10-fold over control mice) have been studied to determine whether they are resistant to CdMT-induced nephrotoxicity. Mice were injected with CdMT (0.1-0.6 mg Cd/kg, iv) and kidney injury was evaluated 24 hr later. CdMT produced renal toxicity in a dose-dependent manner. At a nephrotoxic dose of CdMT (0.4 mg Cd/kg), urinary protein and glucose excretion were increased 30- and 60-fold, respectively, in control mice. However, similar increases in protein and glucose excretion were also observed in MT-transgenic mice. CdMT also induced a similar dose-dependent proximal tubular cell necrosis in both control and MT-transgenic mice in a dose-dependent manner. Treatment of control mice with Zn (100 micromol/kg, sc x 2 days) increased renal MT to levels similar to those of untreated MT-transgenic mice and protected against CdMT-induced renal injury. Furthermore, when Zn (25-100 micromol/kg, sc) was given immediately before CdMT injection (i.e., without preinduction of MT), it was still effective in preventing CdMT nephrotoxicity. We conclude that Zn-induced protection against CdMT nephrotoxicity does not appear to be due to induction of renal MT.  相似文献   
16.
Multicast routing in wireless networks that possess the wireless multicast advantage could significantly reduce the power and energy consumption. However, this kind of multicast routing that only addresses the transmission radius coverage might not be able to meet the bandwidth requirement of the users. As a result, additional transmissions are required to incur more energy consumption and carbon dioxide emissions that make existing algorithms not applicable to bandwidth constrained applications. In this paper, for the first time, we address the bandwidth aware minimum power multicast routing problem in wireless networks where the objective function is to minimize the total power consumption subject to the users?? bandwidth requirements. This problem is a challenging cross-layer design problem that requires seamless and sophisticated integrated design in the network layer (multicast routing) and physical layer (bandwidth-aware wireless transmission and power control). We first formulate this problem as a mixed integer linear programming problem and then propose a Lagrangian relaxation based algorithm to solve this problem. Numerical results demonstrate that the proposed approach is a sound green networking algorithm that outperforms the existing power efficient multicast routing approaches under all tested cases, especially in large bandwidth request, fine radius granularity, large group size and sparse network.  相似文献   
17.
对带有开关电路的2.4 GHz极化分集印刷天线进行电磁场及电磁场与电路协同仿真 通过采用极化分集技术,可以用低成本PCB基片制造具有良好接收机性能的无线局域网设备(WLAN)天线.本文将描述如何使用最新的三维电磁场(EM)仿真工具来设计和仿真一对2.4GHz正交极化的印刷偶极子天线,同时预测表面电流和相关的远场辐射图.  相似文献   
18.
In this study, the thermal conductivity and viscosity of nanofluids, composed of a base fluid and nanoencapsulated phase change material (NEPCM), were investigated experimentally. The NEPCM was prepared by the encapsulation of n-nonadecane as phase change material with diethylenetriamine and toluene-2,4-diisocyanate using interfacial polymerization method. The NEPCM was characterized using scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), and differential scanning calorimetry (DSC) analyses. In the preparation of the nanofluids containing NEPCM, two different base fluids, water and ethylene glycol (EG), were used. The concentration of NEPCM and the working temperature were selected as the main parameters. It was found that the viscosity of the nanofluids decreases with increasing temperature and increases with increasing solid concentration. The viscosity was also expressed as a function of the solid concentration and temperature. The thermal conductivity of the nanofluids was found to increase with increasing temperature. Thermal conductivity exhibited an increasing tendency with increasing solid concentration, but the changes in thermal conductivity according to base fluid are in the range of uncertainty of the measurement for both nanofluids with a solid volumetric fraction lower than 1.68%.  相似文献   
19.
Genetic algorithm is well-known of its best heuristic search method. Fuzzy logic unveils the advantage of interpretability. Genetic fuzzy system exploits potential of optimization with ease of understanding that facilitates rules optimization. This paper presents the optimization of fourteen fuzzy rules for semi expert judgment automation of early activity based duration estimation in software project management. The goal of the optimization is to reduce linguistic terms complexity and improve estimation accuracy of the fuzzy rule set while at the same time maintaining a similar degree of interpretability. The optimized numbers of linguistic terms in fuzzy rules by 27.76% using simplistic binary encoding mechanism managed to improve accuracy by 14.29% and reduce optimization execution time by 6.95% without compromising on interpretability in addition to promote improvement of knowledge base in fuzzy rule based systems.  相似文献   
20.
Journal of Mechanical Science and Technology - Facility layout planning (FLP) has an important role in manufacturing industries. There are few approaches to solve FLP such as procedural,...  相似文献   
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