Efficient Signature Scheme with Batch Verifications in Identity‐Based Framework

In group‐oriented applications, it is often required to verify a group of signatures/messages. The individual verification of signed messages in such applications comes at a high cost in terms of computations and time. To improve computational efficiency and to speed up the verification process, a batch verification technique is a good alternative to individual verification. Such a technique is useful in many real‐world applications, such as mail servers, e‐commerce, banking transactions, and so on. In this work, we propose a new, efficient identity‐based signature (IDS) scheme supporting batch verifications. We prove that the proposed IDS scheme and its various types of batch verifications is tightly related to the Computational Diffie–Hellman problem under a random oracle paradigm. We compare the efficiency of the proposed scheme with related schemes that support batch verifications.     

Fast Duplicate Address Detection for Seamless Inter-Domain Handoff in All-IPv6 Mobile Networks

In All-IP networks, each computer or communication equipment needs an IP address. To supply enough IP addresses, the new Internet protocol IPv6 will be used in next generation mobile communication. Although IPv6 improves the existing Internet protocol (IPv4), Duplicate Address Detection (DAD) mechanism may consume resources and suffer from long delay. DAD is used to make sure whether the IP address is unique or not. When a mobile node performs an inter-domain handoff, it will first generate a new IP and perform a DAD procedure. The DAD procedure not only wastes time but also increases the signaling load on Internet. In this paper, we propose a new DAD mechanism to speed up the DAD procedure. We create a DAD table in access or mobility routers in All-IP networks and record all IP addresses of the area. When a new IP address needs to perform DAD, it can just search in the DAD table to confirm the uniqueness of the address. Furthermore, we propose a new method, Fast Duplicate Address Detection (Fast DAD), to reduce data search time. Simulation results show that our method outperforms the existing DAD methods.     

Magnetic/Fluorescent Barcodes Based on Cadmium‐Free Near‐Infrared‐Emitting Quantum Dots for Multiplexed Detection

Magnetic/fluorescent barcodes, which combine quantum dots (QDs) and superparamagnetic nanoparticles in micrometer‐sized host microspheres, are promising for automatic high‐throughput multiplexed biodetection applications and “point of care” biodetection. However, the fluorescence intensity of QDs sharply decreases after addition of magnetic nanoparticles (MNPs) due to absorption by MNPs, and thus, the encoding capacity of QDs becomes more limited. Furthermore, the intrinsic toxicity of cadmium‐based QDs, the most commonly used QD in barcodes, has significant risks to human health and the environment. In this work, to alleviate fluorescence quenching and intrinsic toxicity, cadmium‐free NIR‐emitting CuInS₂/ZnS QDs and Fe₃O₄ MNPs are successfully incorporated into poly(styrene‐co‐maleic anhydride) microspheres by using the Shirasu porous glass membrane emulsification technique. A “single‐wavelength” encoding model is successfully constructed to guide the encoding of NIR QDs with wide emission spectra. Then, a “single‐wavelength” encoding combined with size encoding is used to produce different optical codes by simply changing the wavelength and the intensity of the QDs as well as the size of the barcode microspheres. 48 barcodes are easily created due to the greatly reduced energy transfer between the NIR‐emitting QDs and MNPs. The resulting bifunctional barcodes are also combined with a flow cytometer using one laser for multiplexed detection of five tumor markers in one test. Assays based on these barcodes are significantly more sensitive than non‐magnetic and traditional ELISA assays. Moreover, validating experiments also show good performance of the bifunctional barcodes‐based suspension array when dealing with patient serum samples. Thus, magnetic/fluorescent barcodes based on NIR‐emitting CuInS₂/ZnS QDs are promising for multiplexed bioassay applications.     

Log‐Polar Coordinate Image Space for the Efficient Detection of Vanishing Points

Log‐polar coordinate image space is proposed as a solution for the problem of unbounded accumulator space in the automatic detection of vanishing points. The proposed method can detect vanishing points at high speed under small memory requirements, as opposed to conventional image space based methods.     

Efficient Near‐Optimal Detection with Generalized Sphere Decoder for Blind MU‐MIMO Systems

In this letter, we propose an efficient near‐optimal detection scheme (that makes use of a generalized sphere decoder (GSD)) for blind multi‐user multiple‐input multiple‐output (MU‐MIMO) systems. In practical MU‐MIMO systems, a receiver suffers from interference because the precoding matrix, the result of the precoding technique used, is quantized with limited feedback and is thus imperfect. The proposed scheme can achieve near‐optimal performance with low complexity by using a GSD to detect several additional interference signals. In addition, the proposed scheme is suitable for use in blind systems.     

Image Restoration by Lifting‐Based Wavelet Domain E‐Median Filter

In this paper, we propose a method of applying a lifting‐based wavelet domain e‐median filter (LBWDEMF) for image restoration. LBWDEMF helps in reducing the number of computations. An e‐median filter is a type of modified median filter that processes each pixel of the output of a standard median filter in a binary manner, keeping the output of the median filter unchanged or replacing it with the original pixel value. Binary decision‐making is controlled by comparing the absolute difference of the median filter output and the original image to a preset threshold. In addition, the advantage of LBWDEMF is that probabilities of encountering root images are spread over sub‐band images, and therefore the e‐median filter is unlikely to encounter root images at an early stage of iterations and generates a better result as iteration increases. The proposed method transforms an image into the wavelet domain using lifting‐based wavelet filters, then applies an e‐median filter in the wavelet domain, transforms the result into the spatial domain, and finally goes through one spatial domain e‐median filter to produce the final restored image. Moreover, in order to validate the effectiveness of the proposed method we compare the result obtained using the proposed method to those using a spatial domain median filter (SDMF), spatial domain e‐median filter (SDEMF), and wavelet thresholding method. Experimental results show that the proposed method is superior to SDMF, SDEMF, and wavelet thresholding in terms of image restoration.     

An Improved Algorithm for Image Edge Detection Based on Lifting Scheme

Wavelet transform is an ideal way for edge detection because of its multi-scale property, localization both in time and frequency domain, sensitivity to the abrupt change of signals,and so on. An improved algorithm for image edge detection based on Lifting Scheme is proposed in this paper. The simulation results show that our improved method can better reflect edge information of images.     

Support Vector Machine Learning for Region‐Based Image Retrieval with Relevance Feedback

We present a relevance feedback approach based on multi‐class support vector machine (SVM) learning and cluster‐merging which can significantly improve the retrieval performance in region‐based image retrieval. Semantically relevant images may exhibit various visual characteristics and may be scattered in several classes in the feature space due to the semantic gap between low‐level features and high‐level semantics in the user's mind. To find the semantic classes through relevance feedback, the proposed method reduces the burden of completely re‐clustering the classes at iterations and classifies multiple classes. Experimental results show that the proposed method is more effective and efficient than the two‐class SVM and multi‐class relevance feedback methods.     

Near‐Infrared SERS Nanoprobes with Plasmonic Au/Ag Hollow‐Shell Assemblies for In Vivo Multiplex Detection

For the effective application of surface‐enhanced Raman scattering (SERS) nanoprobes for in vivo targeting, the tissue transparency of the probe signals should be as high as it can be in order to increase detection sensitivity and signal reproducibility. Here, near‐infrared (NIR)‐sensitive SERS nanoprobes (NIR SERS dots) are demonstrated for in vivo multiplex detection. The NIR SERS dots consist of plasmonic Au/Ag hollow‐shell (HS) assemblies on the surface of silica nanospheres and simple aromatic Raman labels. The diameter of the HS interior is adjusted from 3 to 11 nm by varying the amount of Au³⁺ added, which results in a red‐shift of the plasmonic extinction of the Au/Ag nanoparticles toward the NIR (700–900 nm). The red‐shifted plasmonic extinction of NIR SERS dots causes enhanced SERS signals in the NIR optical window where endogenous tissue absorption coefficients are more than two orders of magnitude lower than those for ultraviolet and visible light. The signals from NIR SERS dots are detectable from 8‐mm deep in animal tissues. Three kinds of NIR SERS dots, which are injected into live animal tissues, produce strong SERS signals from deep tissues without spectral overlap, demonstrating their potential for in vivo multiplex detection of specific target molecules.     

Embedding a Signature in an Image Based on Fractal Compress Transformations

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Constructing Strong Identity‐Based Designated Verifier Signatures with Self‐Unverifiability

An identity‐based strong designated verifier signature scheme provides restricted verifiability only for a verifier designated by a signer and proper privacy for the signer. In this paper, we show that strong designated verifier signature schemes do not satisfy the self‐unverifiability requirement in the sense that not only exposure of the verifier's secret key but also of the signer's secret key enables an attacker to verify signatures, which should have been the exclusive right of the verifier. We also present a generic method to construct a strong identity‐based designated verifier signature scheme with self‐unverifiability from identity‐based key encapsulation and identity‐based key sharing schemes. We prove that a scheme constructed from our method achieves unforgeability, non‐transferability, and self‐unverifiability if the two underlying components are secure. To show the advantage of our method, we present an example that outputs short signatures and we analyze its performance.     

A Water Stable,Near‐Zero‐Strain O3‐Layered Titanium‐Based Anode for Long Cycle Sodium‐Ion Battery

Layered transition metal (TM) oxides of the stoichiometry Na_xMO₂ (M = TM) have shown great promise in sodium‐ion batteries (SIBs); however, they are extremely sensitive to moisture. To date, most reported titanium‐based layered anodes exhibit a P2‐type structure. In contrast, O3‐type compounds are rarely investigated and their synthesis is challenging due to their higher percentage of unstable Ti³⁺ than the P2 type. Here, a pure phase and highly crystalline O3‐type Na_0.73Li_0.36Ti_0.73O₂ with high performance is successfully proposed in SIBs. This material delivers a reversible capacity of 108 mAh g^?1 with a stable and safe potential of 0.75 V versus Na/Na⁺. In situ X‐ray diffraction reveals that this material does not undergo any phase transitions and exhibits a near‐zero volume change upon Na⁺ insertion/de‐insertion, which ensures exceptional long cycle life over 6000 cycles. Importantly, it is found that this O3‐Na_0.73Li_0.36Ti_0.73O₂ shows superior moisture stability, even when immersed into water, which are both elusive for conventional layered TM oxides in SIBs. It is believed that the small interlayer distance and high occupation of interlayer vacancy promise such unprecedented water stability.     

基于小波变换的红外图象多尺度边缘检测

本文讨论了小波变换及其应用于多尺度图象边缘检测的原理，对一幅红外图象给出其多尺度边缘检测的计算机仿真结果，而且与传统的边缘检测方法进行比较，从而得出基于小波变换的多尺度边缘检测是一种较好的方法     

Self‐Propelled Tags for Protein Detection

Protein detection is of tremendous significance for biological and biomedical sciences. Because there is no equivalent of polymerase chain reaction available as a tool for protein detection, researchers must rely on tags to enhance the limits of detection. One of the crucial steps is the actual labeling of proteins, which relies on diffusion of the label, which is very slow, or external mixing of the label and protein is needed. Here, a conceptually new approach is demonstrated: self‐propelled tags that autonomously move in the solution and enhance protein detection. The tags used here are based on IrO₂/Pt bilayer microtubules, which can self‐propel and act as moving tags for enhanced protein electrochemical detection. This completely new label‐based protein detection concept using self‐propelled tag will find a wide spectrum of applications.     

基于数字图像处理的轨道板裂纹缺陷检测

利用数字图像处理技术,通过轨道板图像自动分割、边缘提取、轨道板固有结构边缘去除、真伪裂纹区分等步骤,设计了轨道板裂纹缺陷自动检测识别算法。通过对实际采集的轨道板图像的处理,证明该方法能够准确提取和标记缺陷区域。在实验的1 000幅图像中,人工检出裂纹图像6幅,自动识别裂纹图像6幅,准确率达到100%,算法运行速度经测试能够满足实时检测的需求。     

一个基于视频图像检测火灾的算法

针对传统火灾检测技术在面对大空间结构建筑及复杂环境中的不足,提出一种基于视频图像检测早期火灾的算法。该算法首先对视频图像进行阈值分割,然后根据火焰的颜色特征获取其中的疑似火焰区域。在此基础上计算疑似火焰区域的圆形度,并将圆形度与其整体特性相结合进行火灾的早期探测和预报。     

基于自适应检测算法的ASTER遥感图像机场检测

针对不同时段、区位的遥感图像,通过改进传统Canny算法解决机场快速检测的问题.提出了应用于ASTER SWIR波段遥感图像的机场自适应检测方法,包含图像自适应背景抑制方法、自适应分割阈值生成方法和边缘跟踪连接方法.采用2幅图像进行实验,检测出其中地机场区域.结果表明算法比传统检测算法执行时间减少13%,抗噪性和自适应性提高.     

A Model‐Based Image Steganography Method Using Watson's Visual Model

This paper presents a model‐based image steganography method based on Watson's visual model. Model‐based steganography assumes a model for cover image statistics. This approach, however, has some weaknesses, including perceptual detectability. We propose to use Watson's visual model to improve perceptual undetectability of model‐based steganography. The proposed method prevents visually perceptible changes during embedding. First, the maximum acceptable change in each discrete cosine transform coefficient is extracted based on Watson's visual model. Then, a model is fitted to a low‐precision histogram of such coefficients and the message bits are encoded to this model. Finally, the encoded message bits are embedded in those coefficients whose maximum possible changes are visually imperceptible. Experimental results show that changes resulting from the proposed method are perceptually undetectable, whereas model‐based steganography retains perceptually detectable changes. This perceptual undetectability is achieved while the perceptual quality — based on the structural similarity measure — and the security — based on two steganalysis methods — do not show any significant changes.