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991.
Quality-aware images.   总被引:4,自引:0,他引:4  
We propose the concept of quality-aware image, in which certain extracted features of the original (high-quality) image are embedded into the image data as invisible hidden messages. When a distorted version of such an image is received, users can decode the hidden messages and use them to provide an objective measure of the quality of the distorted image. To demonstrate the idea, we build a practical quality-aware image encoding, decoding and quality analysis system, which employs: 1) a novel reduced-reference image quality assessment algorithm based on a statistical model of natural images and 2) a previously developed quantization watermarking-based data hiding technique in the wavelet transform domain.  相似文献   
992.
提出了一种对标准单元的光学邻近效应校正结果进行复用的方法,并通过将传统标准单元中的所有核心逻辑通过反相器和二选一多路选择器的组合来实现,得到了一套可制造性强的精简标准单元库,从而使OPC复用技术得以有效实施,并将在很大程度上提高芯片生产效率和降低掩模数据存储量.精简标准单元库中单元的电气仿真结果表明其在面积、速度、功耗方面与传统标准单元库相比性能损失很小.  相似文献   
993.
Nanostructured materials with designable microstructure and controllable physical and chemical properties are highly desired for practical applications in nanotechnology. In this article, it is reported that nanoporous copper with a tunable nanopore size can be fabricated by controlling the dealloying process. The influence of acid concentration and etching potential on the formation of nanoprosity is systematically investigated. With optimal etching conditions, the nanopore sizes can be tailored from ~15 to ~120 nm by controlling the dealloying time. It is found that the tunable nanoporosity leads to significant improvements in surface‐enhanced Raman scattering (SERS) of nanoporous copper and peak values of SERS enhancements for both rhodamine 6G and crystal violet 10B molecules are observed at a pore size of ~30–50 nm. This study underscores the effect of complex three‐dimensional nanostructures on physical and chemical properties and is helpful in developing inexpensive SERS substrates for sensitive instrumentations in molecular diagnostics.  相似文献   
994.
Magnetic shape memory alloys (MSMAs) have recently been developed into a new class of functional materials that are capable of magnetic‐field‐induced actuation, mechanical sensing, magnetic refrigeration, and energy harvesting. In the present work, the magnetic &!hyphen;field‐induced martensitic phase transformation (FIPT) in Ni45Mn36.5Co5In13.5 MSMA single crystals is characterized as a new actuation mechanism with potential to result in ultra‐high actuation work outputs. The effects of the applied magnetic field on the transformation temperatures, magnetization, and superelastic response are investigated. The magnetic work output of NiMnCoIn alloys is determined to be more than 1 MJ m?3 per Tesla, which is one order of magnitude higher than that of the most well‐known MSMAs, i.e., NiMnGa alloys. In addition, the work output of NiMnCoIn alloys is orientation independent, potentially surpassing the need for single crystals, and not limited by a saturation magnetic field, as opposed to NiMnGa MSMAs. Experimental and theoretical transformation strains and magnetostress levels are determined as a function of crystal orientation. It is found that [111]‐oriented crystals can demonstrate a magnetostress level of 140 MPa T?1 with 1.2% axial strain under compression. These field‐induced stress and strain levels are significantly higher than those from existing piezoelectric and magnetostrictive actuators. A thermodynamical framework is introduced to comprehend the magnetic energy contributions during FIPT. The present work reveals that the magnetic FIPT mechanism is promising for magnetic actuation applications and provides new opportunities for applications requiring high actuation work‐outputs with relatively large actuation frequencies. One potential issue is the requirement for relatively high critical magnetic fields and field intervals (1.5–3 T) for the onset of FIPT and for reversible FIPT, respectively.  相似文献   
995.
This paper presents a region-based image retrieval system that provides a user interface for helping to specify the watershed regions of interest within a query image. We first propose a new type of visual features, called color-size feature, which includes color-size histogram and moments, to integrate color and region-size information of watershed regions. Next, we design a scheme of region filtering that is based on color-size histogram to fast screen out some of most irrelevant regions and images for the preprocessing of the image retrieval. Our region-based image retrieval system applies the Earth Mover’s Distance in the design of the similarity measure for image ranking and matching. Finally, we present some experiments for the color-size feature, region filtering, and retrieval results that demonstrate the efficiency of our proposed system.  相似文献   
996.
This paper studies the effect of musical stimulations on the capability of the spatial learningmemory in developing rats by behavioral and electrophysiological techniques. Rats, which are exposed to Mozart's Sonata for Two Pianos in D Major, complete learning tasks of the Moriss water maze with significantly shorter latencies, and the power spectrum of alpha band of electrohippocampogram (EHG) significantly increase, compared with the control rats and rats exposed to the horror music. The results indicate that if given the stimulation of Mozart music in the developmental period of the auditory cortex, the capability of the spatial learning-memory can be significantly changed. The enhancement of alpha band of EHG may be related to the change of this function mainly.  相似文献   
997.
Wireless transmission of a patient's electrocardiogram (ECG) signals can be used to reduce cardiac healthcare cost. However, wireless transmissions have high error rates due to radio interference. The ECG signal, where every second of data could mean abnormal patterns, cannot tolerate such losses. Due to this healthcare crisis, the ability for a device to remotely monitor a patient's medication intake and transmit accurate ECG readings, while being cost efficient, is a major innovation. In this research, we integrate a multi‐hop wireless sensor network (WSN) with radio frequency identification (RFID) readers. Our system has two distinct features: (1) remotely supervise patient medication intake via RFID technology, and (2) accurately and remotely transmitting a patient's ECG by adopting extended Kalman filter (EKF) for wireless error recovery. Copyright © 2008 John Wiley & Sons, Ltd.  相似文献   
998.
本文设计了一种基于椭圆曲线密码体制的投票协议,该协议的特点是能够使投票者在计算机网络上进行无记名投票,并可以有效地抵制各种欺骗行为,从而使安全选举成为可能。  相似文献   
999.
在APT系统的对准误差中,定位引起的误差起决定性的作用。CCD的像元分辨力是影响定位精度的主要因素。研究了在如何保持现有硬件条件不变的情况下,通过软件插值的方法实现CCD像元细分,克服传统的质心算法所带来的系统误差。通过实验验证,采用像元细分后,标准差减小了59.4%。  相似文献   
1000.
红外辐射定标是红外遥感信息定量化的关键技术,对所测光谱进行定标是定量分析中的重要环节.给出了两点定标、线性多点定标和非线性多点定标的具体算法,使用傅里叶变换红外光谱仪,测量了HFY-302B和HFY-300B型黑体在不同温度下的辐射谱,其中一些辐射谱用于定标,使用另外一个特定温度下的辐射谱来检验定标结果,结果表明,线性多点定标方法更加准确.  相似文献   
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