WorldWideScience

Sample records for quantization codebook design-part

  1. Limited Feedback Multi-Antenna Quantization Codebook Design-Part II: Multiuser Channels

    CERN Document Server

    Khoshnevis, Behrouz

    2010-01-01

    This is the second part of a two-part paper on optimal design of limited feedback single-user and multiuser spatial multiplexing systems. The first part of the paper studies the single-user system and this part addresses the multiuser case. The problem is cast in form of minimizing the average transmission power at the base station subject to the outage probability constraints at the users' side. The optimization is over the power control function at the base station as well as the users' channel quantization codebooks. The base station has $M$ antennas and serves $M$ single-antenna users, which share a common feedback link with a total rate of $B$ bits per fading block. We first fix the quantization codebooks and study the optimal power control problem which leads to an upper bound for the average transmission sum power. The upper bound solution is then used to optimize the quantization codebooks and to derive the optimal bit allocation laws in the asymptotic regime of $B\\to\\infty$. The paper shows that for ...

  2. Limited Feedback Multi-Antenna Quantization Codebook Design-Part I: Single-User Channels

    CERN Document Server

    Khoshnevis, Behrouz

    2010-01-01

    In this two-part paper, we study the design and optimization of limited feedback single-user and multiuser systems with a multiple-antenna base station and single-antenna users. The design problem is cast in form of minimizing the average transmission power at the base station subject to the outage probability constraints at the users' side. The optimization is over the users' channel quantization codebooks and the transmission power control function at the base station. Our approach is based on fixing the outage scenarios in advance and transforming the design problem into a robust system design problem. The first part of the paper addresses the single-user system and the second part studies the multiuser case. For the single-user case, we start by showing that uniformly quantizing the channel magnitude in dB scale is asymptotically optimal, regardless of the magnitude distribution function. We derive the optimal uniform (in dB) channel magnitude codebook and combine it with a spatially uniform channel direc...

  3. Interframe hierarchical vector quantization using hashing-based reorganized codebook

    Science.gov (United States)

    Choo, Chang Y.; Cheng, Che H.; Nasrabadi, Nasser M.

    1995-12-01

    Real-time multimedia communication over PSTN (Public Switched Telephone Network) or wireless channel requires video signals to be encoded at the bit rate well below 64 kbits/second. Most of the current works on such very low bit rate video coding are based on H.261 or H.263 scheme. The H.263 encoding scheme, for example, consists mainly of motion estimation and compensation, discrete cosine transform, and run and variable/fixed length coding. Vector quantization (VQ) is an efficient and alternative scheme for coding at very low bit rate. One such VQ code applied to video coding is interframe hierarchical vector quantization (IHVQ). One problem of IHVQ, and VQ in general, is the computational complexity due to codebook search. A number of techniques have been proposed to reduce the search time which include tree-structured VQ, finite-state VQ, cache VQ, and hashing based codebook reorganization. In this paper, we present an IHVQ code with a hashing based scheme to reorganize the codebook so that codebook search time, and thus encoding time, can be significantly reduced. We applied the algorithm to the same test environment as in H.263 and evaluated coding performance. It turned out that the performance of the proposed scheme is significantly better than that of IHVQ without hashed codebook. Also, the performance of the proposed scheme was comparable to and often better than that of the H.263, due mainly to hashing based reorganized codebook.

  4. CODEBOOK ENHANCEMENT FOR VECTOR QUANTIZATION USING MINMAX VALUES FOR IMAGE COMPRESSION

    Directory of Open Access Journals (Sweden)

    S. Vimala

    2013-11-01

    Full Text Available Vector Quantization (VQ is one of the Lossy Image Compression Techniques. Vector Quantization comprises of three different phases: Codebook Generation, Image Encoding and Image Decoding. The efficiency of VQ depends on the quality of the codebook. In this paper, we have proposed a novel idea for improving the quality of codebook. The codebook is populated with high detail blocks, with which the edges of the objects in an image can be preserved. The high detail blocks are identified based on the maximum and minimum pixel values of the blocks. K-Means clustering method is also used to improve the quality of the codebook. The quality (PSNR of the reconstructed images by the proposed method is better when compared to that of few existing codebook generation techniques. Standard images are used to test the performance of the proposed method.

  5. Accelerating Families of Fuzzy K-Means Algorithms for Vector Quantization Codebook Design

    Directory of Open Access Journals (Sweden)

    Edson Mata

    2016-11-01

    Full Text Available The performance of signal processing systems based on vector quantization depends on codebook design. In the image compression scenario, the quality of the reconstructed images depends on the codebooks used. In this paper, alternatives are proposed for accelerating families of fuzzy K-means algorithms for codebook design. The acceleration is obtained by reducing the number of iterations of the algorithms and applying efficient nearest neighbor search techniques. Simulation results concerning image vector quantization have shown that the acceleration obtained so far does not decrease the quality of the reconstructed images. Codebook design time savings up to about 40% are obtained by the accelerated versions with respect to the original versions of the algorithms.

  6. 基于免疫猫群优化算法的矢量量化的码书设计及语音识别%Vector Quantization Codebook Design and Speech Recognition Based on Immune Cat Swarm Optimization Algorithm

    Institute of Scientific and Technical Information of China (English)

    杨淑莹; 刘旭鹏; 陶冲; 刘婷婷

    2014-01-01

    在矢量量化的码书设计过程中,针对传统的 LBG算法对初始码书选取的依赖性及易陷入局部最优的缺陷,提出基于免疫猫群优化算法的矢量量化码书设计。将整个种群分为搜索组和跟踪组,运用克隆扩增算子在搜寻组中进行局部搜索,根据适应度值大小调节变异个体数目,保持解的多样性。运用动态疫苗提取与接种算子使跟踪组个体基因与疫苗进行交叉变异,向最优解靠拢,防止无监督交叉变异可能引起的退化现象。通过浓度平衡算子和选择算子更新子代种群,防止种群“早熟”。将训练出全局最优码书输入到HMM模型进行训练和识别,实验结果表明,基于免疫猫群优化算法的矢量量化码书设计不依赖于初始码书选取,鲁棒性强且降低语音识别误差率。%In the process of codebook design, traditional LBG algorithm is often used for vector quantization which depends on the initial codebook selection and easily falls into local optimum. A vector quantization codebook design method based on immune cat swarm optimization algorithm ( ICSO) is proposed to solve the problems. The population is divided into searching group and tracking group. Clonal expansion operator is used for local search in the searching group, and the number of mutation individual is adjusted according to the fitness value. Moreover, dynamic vaccine extraction and vaccination operator are used for global search in the tracking group. The crossover and mutation between individual gene and vaccine make the result close to the optimal solution, and the descendant population is updated through the balance of concentration equilibrium operator and selection operator. Finally, the optimal codebook is obtained from the training vectors by the proposed algorithm and is inputted to the HMM model for training and recognition. The simulation results show that the proposed algorithm does not depend on the

  7. Fast Image Coding Algorithm Using Indirect-Index Codebook Based on SMVQ

    Institute of Scientific and Technical Information of China (English)

    Bin-Bin Xia; An-Hong Wang; Chin-Chen Chang; Li Liu

    2016-01-01

    Abstract-Side-match vector quantization (SMVQ) achieves better compression performance than vector quantization (VQ) in image coding due to its exploration of the dependence of adjacent pixels. However, SMVQ has the disadvantage of requiring excessive time during the process of coding. Therefore, this paper proposes a fast image coding algorithm using indirect-index codebook based on SMVQ (IIC-SMVQ) to reduce the coding time. Two codebooks, named indirect-index codebook (II-codebook) and entire-state codebook (ES-codebook), are trained and utilized. The II-codebook is trained by using the Linde-Buzo-Gray (LBG) algorithm from side-match information, while the ES-codebook is generated from the clustered residual blocks on the basis of the II-codebook. According to the relationship between these two codebooks,the codeword in the II-codebook can be regarded as an indicator to construct a fast search path, which guides in quickly determining the state codebook from the ES-codebook to encode the to-be-encoded block. The experimental results confirm that the coding time of the proposed scheme is shorter than that of the previous SMVQ.

  8. Adaptive codebook selection schemes for image classification in correlated channels

    Science.gov (United States)

    Hu, Chia Chang; Liu, Xiang Lian; Liu, Kuan-Fu

    2015-09-01

    The multiple-input multiple-output (MIMO) system with the use of transmit and receive antenna arrays achieves diversity and array gains via transmit beamforming. Due to the absence of full channel state information (CSI) at the transmitter, the transmit beamforming vector can be quantized at the receiver and sent back to the transmitter by a low-rate feedback channel, called limited feedback beamforming. One of the key roles of Vector Quantization (VQ) is how to generate a good codebook such that the distortion between the original image and the reconstructed image is the minimized. In this paper, a novel adaptive codebook selection scheme for image classification is proposed with taking both spatial and temporal correlation inherent in the channel into consideration. The new codebook selection algorithm is developed to select two codebooks from the discrete Fourier transform (DFT) codebook, the generalized Lloyd algorithm (GLA) codebook and the Grassmannian codebook to be combined and used as candidates of the original image and the reconstructed image for image transmission. The channel is estimated and divided into four regions based on the spatial and temporal correlation of the channel and an appropriate codebook is assigned to each region. The proposed method can efficiently reduce the required information of feedback under the spatially and temporally correlated channels, where each region is adaptively. Simulation results show that in the case of temporally and spatially correlated channels, the bit-error-rate (BER) performance can be improved substantially by the proposed algorithm compared to the one with only single codebook.

  9. Multitask Learning of Compact Semantic Codebooks for Context-aware Scene Modeling.

    Science.gov (United States)

    Wang, Botao; Xiong, Hongkai; Lin, Weiyao; Zou, Junni; Zheng, Yuan F

    2016-09-08

    In the past few decades, we have witnessed the success of bag-of-features (BoF) models in scene classification, object detection and image segmentation. Whereas, it is also well acknowledged that the limitation of BoF-based methods lies in the low-level feature encoding and coarse feature pooling. This paper proposes a novel scene classification method, which leverages several semantic codebooks learned in a multitask fashion for robust feature encoding, and designs a context-aware image representation for efficient feature pooling. Apart from conventional universal codebook learning approaches, the proposed method encodes each class of local features with a unique semantic codebook, which captures the distinct distribution of different semantic classes more effectively. Instead of learning each semantic codebook separately, we learn a compact global codebook, of which each semantic codebook is a sparse subset, with a two-stage iterative multitask learning algorithm. While minimizing the clustering divergence, the semantic codeword assignment is solved by submodular optimization simultaneously. Built upon the global and semantic codebooks, a context-aware image representation is further developed to encode both global and semantic features in image representation via contextual quantization, semantic response computation and semantic pooling. Extensive experiments have been conducted to validate the effectiveness of the proposed method on various public benchmarks with several popular local features.

  10. A New Method of Designing Waveform Codebook

    Institute of Scientific and Technical Information of China (English)

    1998-01-01

    The codebook search takes much operation quantity in CELP coder. The paper puts forward a new method redesigning the waveform codebook known, and lists the experimental data. It has been proved that the operation complexity and transmission bit rate were decreased by using the new codebook, and the synthesis speech quality was high.

  11. Parallelization of the LBG Vector Quantization Algorithm for Shared Memory Systems

    CERN Document Server

    Annaji, Rajashekar

    2009-01-01

    This paper proposes a parallel approach for the Vector Quantization (VQ) problem in image processing. VQ deals with codebook generation from the input training data set and replacement of any arbitrary data with the nearest codevector. Most of the efforts in VQ have been directed towards designing parallel search algorithms for the codebook, and little has hitherto been done in evolving a parallelized procedure to obtain an optimum codebook. This parallel algorithm addresses the problem of designing an optimum codebook using the traditional LBG type of vector quantization algorithm for shared memory systems and for the efficient usage of parallel processors. Using the codebook formed from a training set, any arbitrary input data is replaced with the nearest codevector from the codebook. The effectiveness of the proposed algorithm is indicated.

  12. BSIFT: toward data-independent codebook for large scale image search.

    Science.gov (United States)

    Zhou, Wengang; Li, Houqiang; Hong, Richang; Lu, Yijuan; Tian, Qi

    2015-03-01

    Bag-of-Words (BoWs) model based on Scale Invariant Feature Transform (SIFT) has been widely used in large-scale image retrieval applications. Feature quantization by vector quantization plays a crucial role in BoW model, which generates visual words from the high- dimensional SIFT features, so as to adapt to the inverted file structure for the scalable retrieval. Traditional feature quantization approaches suffer several issues, such as necessity of visual codebook training, limited reliability, and update inefficiency. To avoid the above problems, in this paper, a novel feature quantization scheme is proposed to efficiently quantize each SIFT descriptor to a descriptive and discriminative bit-vector, which is called binary SIFT (BSIFT). Our quantizer is independent of image collections. In addition, by taking the first 32 bits out from BSIFT as code word, the generated BSIFT naturally lends itself to adapt to the classic inverted file structure for image indexing. Moreover, the quantization error is reduced by feature filtering, code word expansion, and query sensitive mask shielding. Without any explicit codebook for quantization, our approach can be readily applied in image search in some resource-limited scenarios. We evaluate the proposed algorithm for large scale image search on two public image data sets. Experimental results demonstrate the index efficiency and retrieval accuracy of our approach.

  13. RF Lens-Embedded Massive MIMO Systems: Fabrication Issues and Codebook Design

    Science.gov (United States)

    Kwon, Taehoon; Lim, Yeon-Geun; Min, Byung-Wook; Chae, Chan-Byoung

    2016-07-01

    In this paper, we investigate a radio frequency (RF) lens-embedded massive multiple-input multiple-output (MIMO) system and evaluate the system performance of limited feedback by utilizing a technique for generating a suitable codebook for the system. We fabricate an RF lens that operates on a 77 GHz (mmWave) band. Experimental results show a proper value of amplitude gain and an appropriate focusing property. In addition, using a simple numerical technique--beam propagation method (BPM)--we estimate the power profile of the RF lens and verify its accordance with experimental results. We also design a codebook--multi-variance codebook quantization (MVCQ)--for limited feedback by considering the characteristics of the RF lens antenna for massive MIMO systems. Numerical results confirm that the proposed system shows significant performance enhancement over a conventional massive MIMO system without an RF lens.

  14. Hierarchical Codebook Design for Massive MIMO

    Directory of Open Access Journals (Sweden)

    Xin Su

    2015-02-01

    Full Text Available The Research of Massive MIMO is an emerging area, since the more antennas the transmitters or receivers equipped with, the higher spectral efficiency and link reliability the system can provide. Due to the limited feedback channel, precoding and codebook design are important to exploit the performance of massive MIMO. To improve the precoding performance, we propose a novel hierarchical codebook with the Fourier-based perturbation matrices as the subcodebook and the Kerdock codebook as the main codebook, which could reduce storage and search complexity due to the finite a lphabet. Moreover, t o f urther r educe t he search complexity and feedback overhead without noticeable performance degradation, we use an adaptive selection algorithm to decide whether to use the subcodebook. Simulation results show that the proposed codebook has remarkable performance gain compared to the conventional Kerdock codebook, without significant increase in feedback overhead and search complexity.

  15. Color quantization and processing by Fibonacci lattices.

    Science.gov (United States)

    Mojsilovic, A; Soljanin, E

    2001-01-01

    Color quantization is sampling of three-dimensional (3-D) color spaces (such as RGB or Lab) which results in a discrete subset of colors known as a color codebook or palette. It is extensively used for display, transfer, and storage of natural images in Internet-based applications, computer graphics, and animation. We propose a sampling scheme which provides a uniform quantization of the Lab space. The idea is based on several results from number theory and phyllotaxy. The sampling algorithm is very much systematic and allows easy design of universal (image-independent) color codebooks for a given set of parameters. The codebook structure allows fast quantization and ordered dither of color images. The display quality of images quantized by the proposed color codebooks is comparable with that of image-dependent quantizers. Most importantly, the quantized images are more amenable to the type of processing used for grayscale ones. Methods for processing grayscale images cannot be simply extended to color images because they rely on the fact that each gray-level is described by a single number and the fact that a relation of full order can be easily established on the set of those numbers. Color spaces (such as RGB or Lab) are, on the other hand, 3-D. The proposed color quantization, i.e., color space sampling and numbering of sampled points, makes methods for processing grayscale images extendible to color images. We illustrate possible processing of color images by first introducing the basic average and difference operations and then implementing edge detection and compression of color quantized images.

  16. Modeling of Vector Quantization Image Coding in an Ant Colony System

    Institute of Scientific and Technical Information of China (English)

    LIXia; LUOXuehui; ZHANGJihong

    2004-01-01

    Ant colony algorithm is a newly emerged stochastic searching optimization algorithm in recent years. In this paper, vector quantization image coding is modeled as a stochastic optimization problem in an Ant colony system (ACS). An appropriately adapted ant colony algorithm is proposed for vector quantization codebook design. Experimental results show that the ACS-based algorithm can produce a better codebook and the improvement of Pixel signal-to-noise ratio (PSNR) exceeds 1dB compared with the conventional LBG algorithm.

  17. A Genetic Clustering Algorithm for Mean-Residual Vector Quantization

    Institute of Scientific and Technical Information of China (English)

    CHUShuchuan; JohnF.Roddick; CHENTsongyi

    2004-01-01

    Vector quantization (VQ) is a useful tool for data compression and can be applied to compress the data vectors in the database. The quality of the recovered data vector depends on a good codebook. Meanresidual vector quantization (M/R VQ) has been shown to be efficient in the encoding time and it only needs a little storage. In this paper, genetic algorithms in combination with the Generalized lloyd algorithm (GLA) are applied to the codebook design of M/R VQ. The mean codebook and residual codebook are trained using GLA algorithm separately, then Genetic algorithms (GA) are used to evaluate and evolve the combined mean codebook and residual codebook. The parameters used in the proposed algorithm are designed based on experiments and they are robust to the proposed GA based clustering algorithm for M/R VQ. Experimental results demonstrate the proposed genetic clustering algorithm applied to M/R VQ may improve the peak signal to noise ratio of the recovered data vector compared with the GLA algorithm.

  18. Design of Image Cryptosystem by Simultaneous VQ-Compression and Shuffling of Codebook and Index Matrix

    CERN Document Server

    Pal, Arup Kumar; Mukhopadhyay, S

    2011-01-01

    The popularity of Internet usage although increases exponentially, it is incapable of providing the security for exchange of confidential data between the users. As a result, several cryptosystems for encryption of data and images have been developed for secured transmission over Internet. In this work, a scheme for Image encryption/decryption based on Vector Quantization (VQ) has been proposed that concurrently encodes the images for compression and shuffles the codebook and the index matrix using pseudorandom sequences for encryption. The processing time of the proposed scheme is much less than the other cryptosystems, because it does not use any traditional cryptographic operations, and instead it performs swapping between the contents of the codebook with respect to a random sequence, which resulted an indirect shuffling of the contents of the index matrix. It may be noted that the security of the proposed cryptosystem depends on the generation and the exchange of the random sequences used. Since the gene...

  19. Codebook Generation Using Partition and Agglomerative Clustering

    Directory of Open Access Journals (Sweden)

    CHANG, C.-T.

    2011-08-01

    Full Text Available In this paper, we present a codebook generation algorithm to produce a codebook with lower distortion. Our method combines a fast codebook generation algorithm (CGAUCD with doubling technique and fast agglomerative clustering algorithm (FACA to generate a codebook with less computing time and lower distortion. Instead of using FACA directly to divide training vectors into M clusters, our proposed method first generates qM clusters from these training vectors, where q>1 is an integer, and then applies FACA to merge these qM clusters into M cells. This is due to the computational complexity of CGAUCD with doubling technique is less than that of FACA. These M cluster centers are used as the initial codebook for CGAUCD. Using three real images as the training set, our method can reduce the MSE and computing time of FPNN+CGAUCD, which is the available best method to our knowledge, by 0.19 to 0.38 and 74.6% to 84.3%, respectively.

  20. Image Coding Based on Address Vector Quantization.

    Science.gov (United States)

    Feng, Yushu

    Image coding is finding increased application in teleconferencing, archiving, and remote sensing. This thesis investigates the potential of Vector Quantization (VQ), a relatively new source coding technique, for compression of monochromatic and color images. Extensions of the Vector Quantization technique to the Address Vector Quantization method have been investigated. In Vector Quantization, the image data to be encoded are first processed to yield a set of vectors. A codeword from the codebook which best matches the input image vector is then selected. Compression is achieved by replacing the image vector with the index of the code-word which produced the best match, the index is sent to the channel. Reconstruction of the image is done by using a table lookup technique, where the label is simply used as an address for a table containing the representative vectors. A code-book of representative vectors (codewords) is generated using an iterative clustering algorithm such as K-means, or the generalized Lloyd algorithm. A review of different Vector Quantization techniques are given in chapter 1. Chapter 2 gives an overview of codebook design methods including the Kohonen neural network to design codebook. During the encoding process, the correlation of the address is considered and Address Vector Quantization is developed for color image and monochrome image coding. Address VQ which includes static and dynamic processes is introduced in chapter 3. In order to overcome the problems in Hierarchical VQ, Multi-layer Address Vector Quantization is proposed in chapter 4. This approach gives the same performance as that of the normal VQ scheme but the bit rate is about 1/2 to 1/3 as that of the normal VQ method. In chapter 5, a Dynamic Finite State VQ based on a probability transition matrix to select the best subcodebook to encode the image is developed. In chapter 6, a new adaptive vector quantization scheme, suitable for color video coding, called "A Self -Organizing

  1. Fast vector quantization using a Bat algorithm for image compression

    Directory of Open Access Journals (Sweden)

    Chiranjeevi Karri

    2016-06-01

    Full Text Available Linde–Buzo–Gray (LBG, a traditional method of vector quantization (VQ generates a local optimal codebook which results in lower PSNR value. The performance of vector quantization (VQ depends on the appropriate codebook, so researchers proposed optimization techniques for global codebook generation. Particle swarm optimization (PSO and Firefly algorithm (FA generate an efficient codebook, but undergoes instability in convergence when particle velocity is high and non-availability of brighter fireflies in the search space respectively. In this paper, we propose a new algorithm called BA-LBG which uses Bat Algorithm on initial solution of LBG. It produces an efficient codebook with less computational time and results very good PSNR due to its automatic zooming feature using adjustable pulse emission rate and loudness of bats. From the results, we observed that BA-LBG has high PSNR compared to LBG, PSO-LBG, Quantum PSO-LBG, HBMO-LBG and FA-LBG, and its average convergence speed is 1.841 times faster than HBMO-LBG and FA-LBG but no significance difference with PSO.

  2. Image compression with embedded wavelet coding via vector quantization

    Science.gov (United States)

    Katsavounidis, Ioannis; Kuo, C.-C. Jay

    1995-09-01

    In this research, we improve Shapiro's EZW algorithm by performing the vector quantization (VQ) of the wavelet transform coefficients. The proposed VQ scheme uses different vector dimensions for different wavelet subbands and also different codebook sizes so that more bits are assigned to those subbands that have more energy. Another feature is that the vector codebooks used are tree-structured to maintain the embedding property. Finally, the energy of these vectors is used as a prediction parameter between different scales to improve the performance. We investigate the performance of the proposed method together with the 7 - 9 tap bi-orthogonal wavelet basis, and look into ways to incorporate loseless compression techniques.

  3. An Improved Interpolative Vector Quantization Scheme for Image Compression

    Directory of Open Access Journals (Sweden)

    Ms. Darshana Chaware

    2013-05-01

    Full Text Available The aim of this paper is to develop a new image compression scheme by introducing visual patterns to interpolative vector quantization (IVQ. In this scheme first input images are down-sampled by ideal filter. Then, the down sampled images are compressed lossly by JPEG and transmitted to the decoder. In the decoder side, the decoded images are first up-sampled to the original resolution. The codebook is designed using LBG algorithm. We introduce visual patterns on designing the codebook. Experiment results shows that our scheme achieves much better performance over JPEG in terms of visual quality and PSNR

  4. Image compression using address-vector quantization

    Science.gov (United States)

    Nasrabadi, Nasser M.; Feng, Yushu

    1990-12-01

    A novel vector quantization scheme, the address-vector quantizer (A-VQ), is proposed which exploits the interblock correlation by encoding a group of blocks together using an address-codebook (AC). The AC is a set of address-codevectors (ACVs), each representing a combination of addresses or indices. Each element of the ACV is an address of an entry in the LBG-codebook, representing a vector-quantized block. The AC consists of an active (addressable) region and an inactive (nonaddressable) region. During encoding the ACVs in the AC are reordered adaptively to bring the most probable ACVs into the active region. When encoding an ACV, the active region is checked, and if such an address combination exists, its index is transmitted to the receiver. Otherwise, the address of each block is transmitted individually. The SNR of the images encoded by the A-VQ method is the same as that of a memoryless vector quantizer, but the bit rate is by a factor of approximately two.

  5. Codebook-based interference alignment for uplink MIMO interference channels

    KAUST Repository

    Lee, Hyun Ho

    2014-02-01

    In this paper, we propose a codebook-based interference alignment (IA) scheme in the constant multiple-input multipleoutput (MIMO) interference channel especially for the uplink scenario. In our proposed scheme, we assume cooperation among base stations (BSs) through reliable backhaul links so that global channel knowledge is available for all BSs, which enables BS to compute the transmit precoder and inform its quantized index to the associated user via limited rate feedback link.We present an upper bound on the rate loss of the proposed scheme and derive the scaling law of the feedback load tomaintain a constant rate loss relative to IA with perfect channel knowledge. Considering the impact of overhead due to training, cooperation, and feedback, we address the effective degrees of freedom (DOF) of the proposed scheme and derive the maximization of the effective DOF. From simulation results, we verify our analysis on the scaling law to preserve the multiplexing gain and confirm that the proposed scheme is more effective than the conventional IA scheme in terms of the effective DOF. © 2014 KICS.

  6. Metrical Quantization

    CERN Document Server

    Klauder, J R

    1998-01-01

    Canonical quantization may be approached from several different starting points. The usual approaches involve promotion of c-numbers to q-numbers, or path integral constructs, each of which generally succeeds only in Cartesian coordinates. All quantization schemes that lead to Hilbert space vectors and Weyl operators---even those that eschew Cartesian coordinates---implicitly contain a metric on a flat phase space. This feature is demonstrated by studying the classical and quantum ``aggregations'', namely, the set of all facts and properties resident in all classical and quantum theories, respectively. Metrical quantization is an approach that elevates the flat phase space metric inherent in any canonical quantization to the level of a postulate. Far from being an unwanted structure, the flat phase space metric carries essential physical information. It is shown how the metric, when employed within a continuous-time regularization scheme, gives rise to an unambiguous quantization procedure that automatically ...

  7. Predictive vector quantization using a neural network approach

    Science.gov (United States)

    Mohsenian, Nader; Rizvi, Syed A.; Nasrabadi, Nasser M.

    1993-07-01

    A new predictive vector quantization (PVQ) technique capable of exploring the nonlinear dependencies in addition to the linear dependencies that exist between adjacent blocks (vectors) of pixels is introduced. The two components of the PVQ scheme, the vector predictor and the vector quantizer, are implemented by two different classes of neural networks. A multilayer perceptron is used for the predictive component and Kohonen self- organizing feature maps are used to design the codebook for the vector quantizer. The multilayer perceptron uses the nonlinearity condition associated with its processing units to perform a nonlinear vector prediction. The second component of the PVQ scheme vector quantizers the residual vector that is formed by subtracting the output of the perceptron from the original input vector. The joint-optimization task of designing the two components of the PVQ scheme is also achieved. Simulation results are presented for still images with high visual quality.

  8. Fourth quantization

    Energy Technology Data Exchange (ETDEWEB)

    Faizal, Mir

    2013-12-18

    In this Letter we will analyze the creation of the multiverse. We will first calculate the wave function for the multiverse using third quantization. Then we will fourth-quantize this theory. We will show that there is no single vacuum state for this theory. Thus, we can end up with a multiverse, even after starting from a vacuum state. This will be used as a possible explanation for the creation of the multiverse. We also analyze the effect of interactions in this fourth-quantized theory.

  9. Kinematical Quantization

    CERN Document Server

    Anderson, Edward

    2016-01-01

    We consider here kinematical quantization: a first and often overlooked step in quantization procedures. $\\mathbb{R}$, $\\mathbb{R}_+$ and the interval are considered, as well as direct (Cartesian) products thereof. Some simple minisuperspace models, and mode by mode consideration of slightly inhomogeneous cosmology, have indefinite signature versions of such kinematical quantizations. The examples in the current paper build in particular toward the case of vacuum $\\mathbb{S}^3$ slightly inhomogeneous cosmology's mode configuration space, which is mathematically a finite time interval slab of Minkowski spacetime.

  10. Neural net approach to predictive vector quantization

    Science.gov (United States)

    Mohsenian, Nader; Nasrabadi, Nasser M.

    1992-11-01

    A new predictive vector quantization (PVQ) technique, capable of exploring the nonlinear dependencies in addition to the linear dependencies that exist between adjacent blocks of pixels, is introduced. Two different classes of neural nets form the components of the PVQ scheme. A multi-layer perceptron is embedded in the predictive component of the compression system. This neural network, using the non-linearity condition associated with its processing units, can perform as a non-linear vector predictor. The second component of the PVQ scheme vector quantizes (VQ) the residual vector that is formed by subtracting the output of the perceptron from the original wave-pattern. Kohonen Self-Organizing Feature Map (KSOFM) was utilized as a neural network clustering algorithm to design the codebook for the VQ technique. Coding results are presented for monochrome 'still' images.

  11. Towards an Efficient Hierarchical Codebooks for Content-Based Images Retrieval

    Institute of Scientific and Technical Information of China (English)

    Z.Elleuch; K.Marzouki

    2014-01-01

    In space feature quantization, the most important problem is designing an efficient and compact codebook. The hierarchical clustering approach successfully solves the problem of quantifying the feature space in a large vocabulary size. In this paper we propose to use a tree structure of hierarchical self-organizing-map (H-SOM) with the depth length equal to two and a high size of branch factors (50, 100, 200, 400, and 500). Moreover, an incremental learning process of H-SOM is used to overcome the problem of the curse of the dimensionality of space. The method is evaluated on three public datasets. Results exceed the current state-of-art retrieval performance on Kentucky and Oxford5k dataset. However, it is with less performance on the Holidays dataset. The experiment results indicate that the proposed tree structure shows significant improvement with a large number of branch factors.

  12. Mode Switching for the Multi-Antenna Broadcast Channel Based on Delay and Channel Quantization

    Directory of Open Access Journals (Sweden)

    Jun Zhang

    2009-01-01

    Full Text Available Imperfect channel state information degrades the performance of multiple-input multiple-output (MIMO communications; its effects on single-user (SU and multiuser (MU MIMO transmissions are quite different. In particular, MU-MIMO suffers from residual interuser interference due to imperfect channel state information while SU-MIMO only suffers from a power loss. This paper compares the throughput loss of both SU and MU-MIMO in the broadcast channel due to delay and channel quantization. Accurate closed-form approximations are derived for achievable rates for both SU and MU-MIMO. It is shown that SU-MIMO is relatively robust to delayed and quantized channel information, while MU-MIMO with zero-forcing precoding loses its spatial multiplexing gain with a fixed delay or fixed codebook size. Based on derived achievable rates, a mode switching algorithm is proposed, which switches between SU and MU-MIMO modes to improve the spectral efficiency based on average signal-to-noise ratio (SNR, normalized Doppler frequency, and the channel quantization codebook size. The operating regions for SU and MU modes with different delays and codebook sizes are determined, and they can be used to select the preferred mode. It is shown that the MU mode is active only when the normalized Doppler frequency is very small, and the codebook size is large.

  13. Tree-Structured Random Vector Quantization for Limited-Feedback Wireless Channel

    CERN Document Server

    Santipach, Wiroonsak

    2011-01-01

    We consider quantizing transmit beamforming vector in a multiantenna channel and signature vector in code division multiple access (CDMA). Assuming perfect channel knowledge, receiver selects for a transmitter the vector that maximizes the performance from a random vector quantization (RVQ) codebook, which consists of independent isotropically distributed unit-norm vectors. The quantized vector is then relayed to the transmitter via a rate-limited feedback channel. The RVQ codebook requires exhaustive search to locate the selected entry. To reduce the search complexity, we apply generalized Lloyd or $k$-dimensional (kd)-tree algorithms to organize RVQ entries into a tree. In examples shown, the search complexity of tree-structured (TS) RVQ can be a few orders of magnitude less than that of the unstructured RVQ for the same performance. We also derive the performance approximation for TS-RVQ in a large system limit, which predicts the performance of moderate-size systems very well.

  14. SAR Image Segmentation using Vector Quantization Technique on Entropy Images

    CERN Document Server

    Kekre, H B; Sarode, Tanuja K

    2010-01-01

    The development and application of various remote sensing platforms result in the production of huge amounts of satellite image data. Therefore, there is an increasing need for effective querying and browsing in these image databases. In order to take advantage and make good use of satellite images data, we must be able to extract meaningful information from the imagery. Hence we proposed a new algorithm for SAR image segmentation. In this paper we propose segmentation using vector quantization technique on entropy image. Initially, we obtain entropy image and in second step we use Kekre's Fast Codebook Generation (KFCG) algorithm for segmentation of the entropy image. Thereafter, a codebook of size 128 was generated for the Entropy image. These code vectors were further clustered in 8 clusters using same KFCG algorithm and converted into 8 images. These 8 images were displayed as a result. This approach does not lead to over segmentation or under segmentation. We compared these results with well known Gray L...

  15. Mathematical quantization

    CERN Document Server

    Weaver, Nik

    2001-01-01

    With a unique approach and presenting an array of new and intriguing topics, Mathematical Quantization offers a survey of operator algebras and related structures from the point of view that these objects are quantizations of classical mathematical structures. This approach makes possible, with minimal mathematical detail, a unified treatment of a variety of topics.Detailed here for the first time, the fundamental idea of mathematical quantization is that sets are replaced by Hilbert spaces. Building on this idea, and most importantly on the fact that scalar-valued functions on a set correspond to operators on a Hilbert space, one can determine quantum analogs of a variety of classical structures. In particular, because topologies and measure classes on a set can be treated in terms of scalar-valued functions, we can transfer these constructions to the quantum realm, giving rise to C*- and von Neumann algebras.In the first half of the book, the author quickly builds the operator algebra setting. He uses this ...

  16. Design of vector quantizer for image compression using self-organizing feature map and surface fitting.

    Science.gov (United States)

    Laha, Arijit; Pal, Nikhil R; Chanda, Bhabatosh

    2004-10-01

    We propose a new scheme of designing a vector quantizer for image compression. First, a set of codevectors is generated using the self-organizing feature map algorithm. Then, the set of blocks associated with each code vector is modeled by a cubic surface for better perceptual fidelity of the reconstructed images. Mean-removed vectors from a set of training images is used for the construction of a generic codebook. Further, Huffman coding of the indices generated by the encoder and the difference-coded mean values of the blocks are used to achieve better compression ratio. We proposed two indices for quantitative assessment of the psychovisual quality (blocking effect) of the reconstructed image. Our experiments on several training and test images demonstrate that the proposed scheme can produce reconstructed images of good quality while achieving compression at low bit rates. Index Terms-Cubic surface fitting, generic codebook, image compression, self-organizing feature map, vector quantization.

  17. Binaural speech enhancement using a codebook based approach

    DEFF Research Database (Denmark)

    Kavalekalam, Mathew Shaji; Christensen, Mads Græsbøll; Boldt, Jesper B.

    2016-01-01

    term predictor (STP) parameters using a codebook based approach, when we have access to binaural noisy signals. The estimated STP parameters are subsequently used for enhancement in a dual channel scenario. Objective measures indicate, that the proposed method is able to improve the speech...

  18. Quantizing Weierstrass

    CERN Document Server

    Bouchard, Vincent; Dauphinee, Tyler

    2016-01-01

    We study the connection between the Eynard-Orantin topological recursion and quantum curves for the family of genus one spectral curves given by the Weierstrass equation. We construct quantizations of the spectral curve that annihilate the perturbative and non-perturbative wave-functions. In particular, for the non-perturbative wave-function, we prove, up to order hbar^5, that the quantum curve satisfies the properties expected from matrix models. As a side result, we obtain an infinite sequence of identities relating A-cycle integrals of elliptic functions and quasi-modular forms.

  19. Fast vector quantization algorithm preserving color image quality

    Science.gov (United States)

    Charrier, Christophe; Cherifi, Hocine

    1998-04-01

    In the color image compression field, it is well known by researchers that the information is statistically redundant. This redundancy is a handicap in terms of dictionary construction time. A way to counterbalance this time consuming effect is to reduce the redundancy within the original image while keeping the image quality. One can extract a random sample of the initial training set on which one constructs the codebook whose quality is equal to the quality of the codebook generated from the entire training set. We applied this idea in the color vector quantization (VQ) compression scheme context. We propose an algorithm to reduce the complexity of the standard LBG technique. We searched for a measure of relevance of each block from the entire training set. Under the assumption that the measure of relevance is a independent random variable, we applied the Kolmogorov statistical test to define the smallest size of a random sample, and then the sample itself. Finally, from blocks associated to each measure of relevance of the random sample, we compute the standard LBG algorithm to construct the codebook. Psychophysics and statistical measures of image quality allow us to find the best measure of relevance to reduce the training set while preserving the image quality and decreasing the computational cost.

  20. Quantized Cosmology

    Energy Technology Data Exchange (ETDEWEB)

    Weinstein, M

    2003-11-19

    This paper discusses the problem of inflation in the context of Friedmann-Robertson-Walker Cosmology. We show how, after a simple change of variables, one can quantize the problem in a way which parallels the classical discussion. The result is that two of the Einstein equations arise as exact equations of motion; one of the usual Einstein equations (suitably quantized) survives as a constraint equation to be imposed on the space of physical states. However, the Friedmann equation, which is also a constraint equation and which is the basis of the Wheeler-DeWitt equation, acquires a welcome quantum correction that becomes significant for small scale factors. We then discuss the extension of this result to a full quantum mechanical derivation of the anisotropy ({delta}{rho}/{rho}) in the cosmic microwave background radiation and the possibility that the extra term in the Friedmann equation could have observable consequences. Finally, we suggest interesting ways in which these techniques can be generalized to cast light on the question of chaotic or eternal inflation. In particular, we suggest that one can put an experimental bound on how far away a universe with a scale factor very different from our own must be, by looking at its effects on our CMB radiation.

  1. Third quantization

    CERN Document Server

    Seligman, Thomas H

    2010-01-01

    The basic ideas of second quantization and Fock space are extended to density operator states, used in treatments of open many-body systems. This can be done for fermions and bosons. While the former only requires the use of a non-orthogonal basis, the latter requires the introduction of a dual set of spaces. In both cases an operator algebra closely resembling the canonical one is developed and used to define the dual sets of bases. We here concentrated on the bosonic case where the unboundedness of the operators requires the definitions of dual spaces to support the pair of bases. Some applications, mainly to non-equilibrium steady states, will be mentioned.

  2. Third quantization

    Science.gov (United States)

    Seligman, Thomas H.; Prosen, Tomaž

    2010-12-01

    The basic ideas of second quantization and Fock space are extended to density operator states, used in treatments of open many-body systems. This can be done for fermions and bosons. While the former only requires the use of a non-orthogonal basis, the latter requires the introduction of a dual set of spaces. In both cases an operator algebra closely resembling the canonical one is developed and used to define the dual sets of bases. We here concentrated on the bosonic case where the unboundedness of the operators requires the definitions of dual spaces to support the pair of bases. Some applications, mainly to non-equilibrium steady states, will be mentioned.

  3. Improved vector quantization scheme for grayscale image compression

    Science.gov (United States)

    Hu, Y.-C.; Chen, W.-L.; Lo, C.-C.; Chuang, J.-C.

    2012-06-01

    This paper proposes an improved image coding scheme based on vector quantization. It is well known that the image quality of a VQ-compressed image is poor when a small-sized codebook is used. In order to solve this problem, the mean value of the image block is taken as an alternative block encoding rule to improve the image quality in the proposed scheme. To cut down the storage cost of compressed codes, a two-stage lossless coding approach including the linear prediction technique and the Huffman coding technique is employed in the proposed scheme. The results show that the proposed scheme achieves better image qualities than vector quantization while keeping low bit rates.

  4. Reduced-Complexity Deterministic Annealing for Vector Quantizer Design

    Directory of Open Access Journals (Sweden)

    Ortega Antonio

    2005-01-01

    Full Text Available This paper presents a reduced-complexity deterministic annealing (DA approach for vector quantizer (VQ design by using soft information processing with simplified assignment measures. Low-complexity distributions are designed to mimic the Gibbs distribution, where the latter is the optimal distribution used in the standard DA method. These low-complexity distributions are simple enough to facilitate fast computation, but at the same time they can closely approximate the Gibbs distribution to result in near-optimal performance. We have also derived the theoretical performance loss at a given system entropy due to using the simple soft measures instead of the optimal Gibbs measure. We use thederived result to obtain optimal annealing schedules for the simple soft measures that approximate the annealing schedule for the optimal Gibbs distribution. The proposed reduced-complexity DA algorithms have significantly improved the quality of the final codebooks compared to the generalized Lloyd algorithm and standard stochastic relaxation techniques, both with and without the pairwise nearest neighbor (PNN codebook initialization. The proposed algorithms are able to evade the local minima and the results show that they are not sensitive to the choice of the initial codebook. Compared to the standard DA approach, the reduced-complexity DA algorithms can operate over 100 times faster with negligible performance difference. For example, for the design of a 16-dimensional vector quantizer having a rate of 0.4375 bit/sample for Gaussian source, the standard DA algorithm achieved 3.60 dB performance in 16 483 CPU seconds, whereas the reduced-complexity DA algorithm achieved the same performance in 136 CPU seconds. Other than VQ design, the DA techniques are applicable to problems such as classification, clustering, and resource allocation.

  5. Quantized Neighbourhoods

    CERN Document Server

    Arrighi, Pablo; Werner, Reinhard

    2009-01-01

    Consider a set of physical systems, evolving according to some global dynamics yielding another set of physical systems. Such a global dynamics f may have a causal structure, i.e. each output physical system may depend only on some subset of the input physical system, whom we may call its "neighbours". We can of course write down these dependencies, and hence formalize them in a bipartite graph labeled with the physical systems sitting at each node, with the first (resp. second) set holding the global state of the composite physical system at time t (resp. t'), and the edges between the partition stating which physical systems may influence which. Moreover if f is bijective, then we can quantize just by linear extension, so that it now turns into a unitary operator Q(f) acting upon this set of, now quantum, physical systems. The question we address is: what becomes, then, of the dependency graph? In other words, has Q(f) got the same causal structure as f? The answer to this question turns out to be a surpris...

  6. Outage behavior of slow fading channels with power control using noisy quantized CSIT

    CERN Document Server

    Ekbatani, Siavash; Jafarkhani, Hamid

    2008-01-01

    The topic of this study is the outage behavior of multiple-antenna slow fading channels with quantized feedback and partial power control. A fixed-rate communication system is considered. It is known from the literature that with error-free feedback, the outage-optimal quantizer for power control has a circular structure. Moreover, the diversity gain of the system increases polynomially with the cardinality of the power control codebook. Here, a similar system is studied, but when the feedback link is error-prone. We prove that in the high-SNR regime, the optimal quantizer structure with noisy feedback is still circular and the optimal Voronoi regions are contiguous non-zero probability intervals. Furthermore, the optimal power control codebook resembles a channel optimized scalar quantizer (COSQ), i.e., the Voronoi regions merge with erroneous feedback information. Using a COSQ, the outage performance of the system is superior to that of a no-feedback scheme. However, asymptotic analysis shows that the diver...

  7. High fidelity adaptive vector quantization at very low bit rates for progressive transmission of radiographic images

    Science.gov (United States)

    Mitra, Sunanda; Yang, Shu Y.

    1999-01-01

    An adaptive vector quantizer (VQ) using a clustering technique known as adaptive fuzzy leader clustering (AFLC) that is similar in concept to deterministic annealing for VQ codebook design has been developed. This vector quantizer, AFLC-VQ, has been designed to vector quantize wavelet decomposed sub images with optimal bit allocation. The high- resolution sub images at each level have been statistically analyzed to conform to generalized Gaussian probability distributions by selecting the optimal number of filter taps. The adaptive characteristics of AFLC-VQ result from AFLC, an algorithm that uses self-organizing neural networks with fuzzy membership values of the input samples for upgrading the cluster centroids based on well known optimization criteria. By generating codebooks containing codewords of varying bits, AFLC-VQ is capable of compressing large color/monochrome medical images at extremely low bit rates (0.1 bpp and less) and yet yielding high fidelity reconstructed images. The quality of the reconstructed images formed by AFLC-VQ has been compared with JPEG and EZW, the standard and the well known wavelet based compression technique (using scalar quantization), respectively, in terms of statistical performance criteria as well as visual perception. AFLC-VQ exhibits much better performance than the above techniques. JPEG and EZW were chosen as comparative benchmarks since these have been used in radiographic image compression. The superior performance of AFLC-VQ over LBG-VQ has been reported in earlier papers.

  8. 基于多视觉码本的图像表示%Image Representation Based on Multiple Visual Codebooks

    Institute of Scientific and Technical Information of China (English)

    宋彦; 蒋兵; 戴礼荣

    2013-01-01

    基于词袋模型的图像表示方法的有效性主要受限于局部特征的量化误差。文中提出一种基于多视觉码本的图像表示方法,通过综合考虑码本构建和编码方法这两个方面的因素加以改进。具体包括:1)多视觉码本构建,以迭代方式构建多个紧凑且具有互补性的视觉码本;2)图像表示,首先针对多码本的情况,依次从各码本中选择相应的视觉单词并采用线性回归估计编码系数,然后结合图像的空间金字塔结构形成最终的图像表示。在一些标准测试集合的图像分类结果验证文中方法的有效性。%The effectiveness of the image representation based on bag-of-visual words( BoW) model is majorly limited by the quantization error. To address this issue, an improved image representation based on multiple visual codebooks is proposed in this paper, which considers both visual codebook construction and feature coding. The proposed method specifically consists of 1 ) multiple visual codebooks construction, in which the compact and complementary visual codebooks are iteratively generated; 2 ) image representation, in which the visual words are firstly selected from each individual visual codebook, then the coding coefficients are determined by using the regularized linear regression method, and finally the image is represented by combining the spatial pyramid structure. The experimental results on several benchmark image classification datasets demonstrate the consistent and significant improvement of the proposed method.

  9. ASYMPTOTIC QUANTIZATION OF PROBABILITY DISTRIBUTIONS

    Institute of Scientific and Technical Information of China (English)

    Klaus P(o)tzelberger

    2003-01-01

    We give a brief introduction to results on the asymptotics of quantization errors.The topics discussed include the quantization dimension,asymptotic distributions of sets of prototypes,asymptotically optimal quantizations,approximations and random quantizations.

  10. Developing a codebook to guide content analysis of expressive writing transcripts.

    Science.gov (United States)

    Fonteyn, Marsha E; Vettese, Margaret; Lancaster, Diane R; Bauer-Wu, Susan

    2008-08-01

    This article describes a team-based approach to the development of a comprehensive codebook for multiple researchers to use during content analysis of the transcripts of the expressive writings of women (in this study, N = 89) with metastatic breast cancer. The codebook structure was developed iteratively by reaching a consensus on the analysis of shared transcripts to create an all-encompassing set of codes, with definitions, inclusion and exclusion criteria, and exemplar text from the transcripts. The Qualitative Solutions and Research International NVivo software program was used to maintain an electronic database of the consensus analysis of transcripts, information about each code, and a detailed log about the process of developing the codebook. The team ultimately created a comprehensive codebook that contained 27 codes with definitions, inclusion and exclusion criteria, and example text. The codes were verified by each team member through reanalysis of a set of shared transcripts that had been previously coded using an earlier version of the codebook. The team met to discuss individual coding and reached a consensus on the final version of the codebook. No new code was identified during the reanalysis, and there was fairly uniform agreement on the coding. The final version of the codebook will be used to guide each team member's individual analysis of the remaining (74) transcripts, which will be divided among the team. Periodic meetings are planned to discuss the individual analysis and to resolve any issue associated with using the codebook. As new codes are identified and agreed upon by the team, they will be added to the codebook. A team-based approach can facilitate the development of a practical and accurate codebook to guide the analysis of a large amount of qualitative data.

  11. Covariant canonical quantization

    Energy Technology Data Exchange (ETDEWEB)

    Hippel, G.M. von [University of Regina, Department of Physics, Regina, Saskatchewan (Canada); Wohlfarth, M.N.R. [Universitaet Hamburg, Institut fuer Theoretische Physik, Hamburg (Germany)

    2006-09-15

    We present a manifestly covariant quantization procedure based on the de Donder-Weyl Hamiltonian formulation of classical field theory. This procedure agrees with conventional canonical quantization only if the parameter space is d=1 dimensional time. In d>1 quantization requires a fundamental length scale, and any bosonic field generates a spinorial wave function, leading to the purely quantum-theoretical emergence of spinors as a byproduct. We provide a probabilistic interpretation of the wave functions for the fields, and we apply the formalism to a number of simple examples. These show that covariant canonical quantization produces both the Klein-Gordon and the Dirac equation, while also predicting the existence of discrete towers of identically charged fermions with different masses. Covariant canonical quantization can thus be understood as a ''first'' or pre-quantization within the framework of conventional QFT. (orig.)

  12. Coding of hyperspectral imagery using adaptive classification and trellis-coded quantization

    Science.gov (United States)

    Abousleman, Glen P.

    1997-08-01

    A system is presented for compression of hyperspectral imagery. Specifically, DPCM is used for spectral decorrelation, while an adaptive 2D discrete cosine transform coding scheme is used for spatial decorrelation. Trellis coded quantization is used to encode the transform coefficients. Side information and rate allocation strategies are discussed. Entropy-constrained codebooks are designed using a modified version of the generalized Lloyd algorithm. This entropy constrained system achieves a compression ratio of greater than 70:1 with an average PSNR of the coded hyperspectral sequence approaching 41 dB.

  13. Hierarchical CodeBook for background subtraction in MRF

    Science.gov (United States)

    Shao, Quan; Tang, Zhixing; Han, Songchen

    2013-11-01

    Foreground detection is the key low-level fundamental work in intelligent video surveillance. This paper proposed a hierarchical background subtraction algorithm consisted of block-based stage and pixel-based stage for it. In block-based stage, obvious backgrounds got detected via block-based CodeBook, leaving spatial relations among suspicious foreground pixels undestroyed. Pixel-based stage further eliminated the left background pixels with the introduction of spatial and temporal relations in a MRF-MAP framework. Then comparative experiments were conducted to evaluate the performance of the scheme in three dimensions - detection accuracy, update speed and memory consumption. Proposed approach possesses the highest detection precision and consumes the second least memories. And the update speed is of real-time level.

  14. Resolving-Power Quantization

    CERN Document Server

    Neuberger, Herbert

    2016-01-01

    Starting with a general discussion, a program is sketched for a quantization based on dilations. This resolving-power quantization is simplest for scalar field theories. The hope is to find a way to relax the requirement of locality so that the necessity to fine tune mass parameters is eliminated while universality is still preserved.

  15. Rhythm quantization for transcription

    NARCIS (Netherlands)

    Cemgil, A.T.; Desain, P.W.M.; Kappen, H.J.

    1999-01-01

    Automatic Music Transcription is the extraction of an acceptable notation from performed music. One important task in this problem is rhythm quantization which refers to categorization of note durations. Although quantization of a pure mechanical performance is rather straightforward, the task becom

  16. Generalized Quantization Condition

    Institute of Scientific and Technical Information of China (English)

    LIANG Zheng; CAO Zhuang-Qi; DENG Xiao-Xu; SHEN Qi-Shun

    2005-01-01

    @@ On the basis of analytical transfer matrix theory, we fine a generalized quantization condition. By introducing a new type of modified momentum, our quantization condition has the same form as the Bohr-Sommerfeld formula.Numerical and analytical comparisons show that the present method is exact.

  17. Covariant canonical quantization

    CERN Document Server

    Von Hippel, G M; Hippel, Georg M. von; Wohlfarth, Mattias N.R.

    2006-01-01

    We present a manifestly covariant quantization procedure based on the de Donder-Weyl Hamiltonian formulation of classical field theory. Covariant canonical quantization agrees with conventional canonical quantization only if the parameter space is d=1 dimensional time. In d>1 quantization requires a fundamental length scale, and any bosonic field generates a spinorial wave function, leading to the purely quantum-theoretical emergence of spinors as a byproduct. We provide a probabilistic interpretation of the wave functions for the fields, and apply the formalism to a number of simple examples. These show that covariant canonical quantization produces both the Klein-Gordon and the Dirac equation, while also predicting the existence of discrete towers of identically charged fermions with different masses.

  18. Quantized beam shifts

    CERN Document Server

    Kort-Kamp, W J M; Dalvit, D A R

    2015-01-01

    We predict quantized Imbert-Fedorov, Goos-H\\"anchen, and photonic spin Hall shifts for light beams impinging on a graphene-on-substrate system in an external magnetic field. In the quantum Hall regime the Imbert-Fedorov and photonic spin Hall shifts are quantized in integer multiples of the fine structure constant $\\alpha$, while the Goos- H\\"anchen ones in multiples of $\\alpha^2$. We investigate the influence on these shifts of magnetic field, temperature, and material dispersion and dissipation. An experimental demonstration of quantized beam shifts could be achieved at terahertz frequencies for moderate values of the magnetic field.

  19. CODEVECTOR MODELING USING LOCAL POLYNOMIAL REGRESSION FOR VECTOR QUANTIZATION BASED IMAGE COMPRESSION

    Directory of Open Access Journals (Sweden)

    P. Arockia Jansi Rani

    2010-08-01

    Full Text Available Image compression is very important in reducing the costs of data storage and transmission in relatively slow channels. In this paper, a still image compression scheme driven by Self-Organizing Map with polynomial regression modeling and entropy coding, employed within the wavelet framework is presented. The image compressibility and interpretability are improved by incorporating noise reduction into the compression scheme. The implementation begins with the classical wavelet decomposition, quantization followed by Huffman encoder. The codebook for the quantization process is designed using an unsupervised learning algorithm and further modified using polynomial regression to control the amount of noise reduction. Simulation results show that the proposed method reduces bit rate significantly and provides better perceptual quality than earlier methods.

  20. A Hashing-Based Search Algorithm for Coding Digital Images by Vector Quantization

    Science.gov (United States)

    Chu, Chen-Chau

    1989-11-01

    This paper describes a fast algorithm to compress digital images by vector quantization. Vector quantization relies heavily on searching to build codebooks and to classify blocks of pixels into code indices. The proposed algorithm uses hashing, localized search, and multi-stage search to accelerate the searching process. The average of pixel values in a block is used as the feature for hashing and intermediate screening. Experimental results using monochrome images are presented. This algorithm compares favorably with other methods with regard to processing time, and has comparable or better mean square error measurements than some of them. The major advantages of the proposed algorithm are its speed, good quality of the reconstructed images, and flexibility.

  1. Metrics for vector quantization-based parametric speech enhancement and separation

    DEFF Research Database (Denmark)

    Christensen, Mads Græsbøll

    2013-01-01

    Speech enhancement and separation algorithms sometimes employ a two-stage processing scheme, wherein the signal is first mapped to an intermediate low-dimensional parametric description after which the parameters are mapped to vectors in codebooks trained on, for exam- ple, individual noise......-free sources using a vector quantizer. To obtain accurate parameters, one must employ a good estimator in finding the parameters of the intermediate representation, like a maximum like- lihood estimator. This leaves some unanswered questions, however, like what metrics to use in the subsequent vector...... quantization process and how to systematically derive them. This paper aims at answering these questions. Metrics for this are presented and derived, and their use is exemplified on a number of different signal models by deriving closed-form expressions. The metrics essentially take into account in the vector...

  2. Electronic Codebooks for Windows 95/98: 22 ECBs. Electronic Codebook (ECB) Updates for Previously Released Data Files. [CD-ROM].

    Science.gov (United States)

    National Center for Education Statistics (ED), Washington, DC.

    This CD-ROM contains a separate electronic codebook for each of the following National Center for Education Statistics data sets: (1) B94, Baccalaureate and Beyond 1993-94 (restricted); (2) B97, Baccalaureate and Beyond 1993-97 (restricted); (3) BP4, Beginning Postsecondary Students 1990-94 (restricted); (4) FAC, 1992-93 National Student of…

  3. On channel quantization for multi-cell cooperative systems with limited feedback

    Institute of Scientific and Technical Information of China (English)

    HOU XueYing; YANG ChenYang; LAU Buon Kiong

    2013-01-01

    Coherent multi-cell cooperative transmission, also referred to as coordinated multi-point transmission (CoMP), is a promising strategy to provide high spectral efficiency for universal frequency reuse cellular systems. To report the required channel information to the transmitter in frequency division duplexing systems, limited feedback techniques are often applied. Considering that the average channel gains from multiple base stations (BSs) to one mobile station are different and the number of cooperative BSs may be dynamic, it is neither flexible nor compatible to employ a large codebook to directly quantize the CoMP channel. In this paper, we employ per-cell codebooks for quantizing local and cross channels. We first propose a codeword selection criterion, aiming at maximizing an estimated data rate for each user. The proposed criterion can be applied for an arbitrary number of receive antennas at each user and also for an arbitrary number of data streams transmitted to each user. Considering that the resulting optimal per-cell codeword selection for CoMP channel is of high complexity, we propose a serial codeword selection method that has low complexity but yields comparable performance to that of the optimal codeword selection. We evaluate the proposed codeword selection criterion and method using measured CoMP channels from an urban environment as well as simulations. The results demonstrate significant performance gain as compared to an existing low-complexity method.

  4. General Quantization Rule

    CERN Document Server

    Maiz, F

    2012-01-01

    A general quantization rule for bound states of the Schrodinger equation is presented. Like fundamental theory of integral, our idea is mainly based on dividing the potential into many pieces, solving the Schr\\"odinger equation, and deriving the general quantization rule. For both exactly and non-exactly solvable systems, the energy levels of all the bound states can be easily calculated from the general quantization rule. Using this new general quantization rule, we re-calculate the energy levels for the one-dimensional system, with an infinite square well, with the harmonic oscillator potential, with the Morse Potential, with the symmetric and asymmetric Rosen-Morse potentials, with the first P\\"oschl-Teller potential, with the Coulomb Potential, with the V-shape Potential, and the ax^4 potential, and for the three dimensions systems, with the harmonic oscillator potential, with the ordinary Coulomb potential, and for the hydrogen atom.

  5. Quantization of Emergent Gravity

    CERN Document Server

    Yang, Hyun Seok

    2013-01-01

    Emergent gravity is based on a novel form of the equivalence principle known as the Darboux theorem or the Moser lemma in symplectic geometry stating that the electromagnetic force can always be eliminated by a local coordinate transformation as far as spacetime admits a symplectic structure, in other words, a microscopic spacetime becomes noncommutative (NC). If gravity emerges from U(1) gauge theory on NC spacetime, this picture of emergent gravity suggests a completely new quantization scheme where quantum gravity is defined by quantizing spacetime itself, leading to a dynamical NC spacetime. Therefore the quantization of emergent gravity is radically different from the conventional approach trying to quantize a phase space of metric fields. This approach for quantum gravity allows a background independent formulation where spacetime as well as matter fields is equally emergent from a universal vacuum of quantum gravity.

  6. Quantization of emergent gravity

    Science.gov (United States)

    Yang, Hyun Seok

    2015-02-01

    Emergent gravity is based on a novel form of the equivalence principle known as the Darboux theorem or the Moser lemma in symplectic geometry stating that the electromagnetic force can always be eliminated by a local coordinate transformation as far as space-time admits a symplectic structure, in other words, a microscopic space-time becomes noncommutative (NC). If gravity emerges from U(1) gauge theory on NC space-time, this picture of emergent gravity suggests a completely new quantization scheme where quantum gravity is defined by quantizing space-time itself, leading to a dynamical NC space-time. Therefore the quantization of emergent gravity is radically different from the conventional approach trying to quantize a phase space of metric fields. This approach for quantum gravity allows a background-independent formulation where space-time and matter fields are equally emergent from a universal vacuum of quantum gravity.

  7. Riemann surface and quantization

    Science.gov (United States)

    Perepelkin, E. E.; Sadovnikov, B. I.; Inozemtseva, N. G.

    2017-01-01

    This paper proposes an approach of the unified consideration of classical and quantum mechanics from the standpoint of the complex analysis effects. It turns out that quantization can be interpreted in terms of the Riemann surface corresponding to the multivalent LnΨ function. A visual interpretation of "trajectories" of the quantum system and of the Feynman's path integral is presented. A magnetic dipole having a magnetic charge that satisfies the Dirac quantization rule was obtained.

  8. Lagrange structure and quantization

    Energy Technology Data Exchange (ETDEWEB)

    Kazinski, Peter O. [Department of Quantum Field Theory, Tomsk State University, Tomsk 634050 (Russian Federation); Lyakhovich, Simon L. [Department of Quantum Field Theory, Tomsk State University, Tomsk 634050 (Russian Federation); Sharapov, Alexey A. [Department of Quantum Field Theory, Tomsk State University, Tomsk 634050 (Russian Federation)

    2005-07-01

    A path-integral quantization method is proposed for dynamical systems whose classical equations of motion do not necessarily follow from the action principle. The key new notion behind this quantization scheme is the Lagrange structure which is more general than the lagrangian formalism in the same sense as Poisson geometry is more general than the symplectic one. The Lagrange structure is shown to admit a natural BRST description which is used to construct an AKSZ-type topological sigma-model. The dynamics of this sigma-model in d+1 dimensions, being localized on the boundary, are proved to be equivalent to the original theory in d dimensions. As the topological sigma-model has a well defined action, it is path-integral quantized in the usual way that results in quantization of the original (not necessarily lagrangian) theory. When the original equations of motion come from the action principle, the standard BV path-integral is explicitly deduced from the proposed quantization scheme. The general quantization scheme is exemplified by several models including the ones whose classical dynamics are not variational.

  9. Action Quantization, Energy Quantization, and Time Parametrization

    Science.gov (United States)

    Floyd, Edward R.

    2017-03-01

    The additional information within a Hamilton-Jacobi representation of quantum mechanics is extra, in general, to the Schrödinger representation. This additional information specifies the microstate of ψ that is incorporated into the quantum reduced action, W. Non-physical solutions of the quantum stationary Hamilton-Jacobi equation for energies that are not Hamiltonian eigenvalues are examined to establish Lipschitz continuity of the quantum reduced action and conjugate momentum. Milne quantization renders the eigenvalue J. Eigenvalues J and E mutually imply each other. Jacobi's theorem generates a microstate-dependent time parametrization t-τ =partial _E W even where energy, E, and action variable, J, are quantized eigenvalues. Substantiating examples are examined in a Hamilton-Jacobi representation including the linear harmonic oscillator numerically and the square well in closed form. Two byproducts are developed. First, the monotonic behavior of W is shown to ease numerical and analytic computations. Second, a Hamilton-Jacobi representation, quantum trajectories, is shown to develop the standard energy quantization formulas of wave mechanics.

  10. Using Geometrical Properties for Fast Indexation of Gaussian Vector Quantizers

    Directory of Open Access Journals (Sweden)

    Vassilieva EA

    2007-01-01

    Full Text Available Vector quantization is a classical method used in mobile communications. Each sequence of samples of the discretized vocal signal is associated to the closest -dimensional codevector of a given set called codebook. Only the binary indices of these codevectors (the codewords are transmitted over the channel. Since channels are generally noisy, the codewords received are often slightly different from the codewords sent. In order to minimize the distortion of the original signal due to this noisy transmission, codevectors indexed by one-bit different codewords should have a small mutual Euclidean distance. This paper is devoted to this problem of index assignment of binary codewords to the codevectors. When the vector quantizer has a Gaussian structure, we show that a fast index assignment algorithm based on simple geometrical and combinatorial considerations can improve the SNR at the receiver by 5dB with respect to a purely random assignment. We also show that in the Gaussian case this algorithm outperforms the classical combinatorial approach in the field.

  11. SOLIDWORKS SIMULATIONEXPRESS ANALYSYS ON A DESIGNED PART

    Directory of Open Access Journals (Sweden)

    Cătălin IANCU

    2015-05-01

    Full Text Available In this paperwork are presented the SolidWorks analysis steps taken for to preliminary strength study of a designed part, using SimulationExpress module. There are presented the settings that have to be done for such analysis and the results shown by this software module. The MEF elements that are taken into account are specific to a static analysis completed with imposed safety factor distribution.

  12. SOLIDWORKS COSTING ANALYSYS ON A DESIGNED PART

    Directory of Open Access Journals (Sweden)

    Catalin IANCU

    2016-05-01

    Full Text Available In this paperwork are presented the SolidWorks analysis steps taken for costing study of a designed part, using Costing module. There are presented the settings that have to be done for such analysis and the results shown by this software module. The costing elements that are taken into account are specific to default costing templates in SolidWorks, but can be adjusted (edited to costs specific to a given enterprise.

  13. Hyperspectral image compression using 3D discrete cosine transform and entropy-constrained trellis-coded quantization

    Science.gov (United States)

    Abousleman, Glen P.; Marcellin, Michael W.; Hunt, Bobby R.

    1994-07-01

    A system is presented for compression of hyperspectral imagery which utilizes trellis coded quantization (TCQ). Specifically, TCQ is used to encode transform coefficients resulting from the application of an 8X8X8 discrete cosine transform. Side information and rate allocation strategies are discussed. Entropy-constrained codebooks are designed using a modified version of the generalized Lloyd algorithm. This entropy constrained system achieves a compression ratio of greater than 70:1 with an average PSNR of the coded hyperspectral sequence exceeding 40.5 dB.

  14. An introduction to field quantization

    CERN Document Server

    Takahashi, Yasushi

    1969-01-01

    An Introduction to Field Quantization is an introductory discussion of field quantization and problems closely related to it. Field quantization establishes a commutation relation of the field and finds an operator in such a manner that the Heisenberg equation of motion is satisfied. This book contains eight chapters and begins with a review of the quantization of the Schroedinger field and the close relation between quantized field theory and the many-body theory in quantum mechanics. These topics are followed by discussions of the quantization of the radiation field and the field of lattice

  15. Lagrange structure and quantization

    CERN Document Server

    Kazinski, P O; Sharapov, A A

    2005-01-01

    A path-integral quantization method is proposed for dynamical systems whose classical equations of motion do \\textit{not} necessarily follow from the action principle. The key new notion behind this quantization scheme is the Lagrange structure which is more general than the Lagrangian formalism in the same sense as Poisson geometry is more general than the symplectic one. The Lagrange structure is shown to admit a natural BRST description which is used to construct an AKSZ-type topological sigma-model. The dynamics of this sigma-model in $d+1$ dimensions, being localized on the boundary, are proved to be equivalent to the original theory in $d$ dimensions. As the topological sigma-model has a well defined action, it is path-integral quantized in the usual way that results in quantization of the original (not necessarily Lagrangian) theory. When the original equations of motion come from the action principle, the standard BV path-integral is explicitly deduced from the proposed quantization scheme. The genera...

  16. Black hole entropy quantization

    CERN Document Server

    Corichi, A; Fernandez-Borja, E; Corichi, Alejandro; Diaz-Polo, Jacobo; Fernandez-Borja, Enrique

    2006-01-01

    Ever since the pioneer works of Bekenstein and Hawking, black hole entropy has been known to have a quantum origin. Furthermore, it has long been argued by Bekenstein that entropy should be quantized in discrete (equidistant) steps given its identification with horizon area in (semi-)classical general relativity and the properties of area as an adiabatic invariant. This lead to the suggestion that black hole area should also be quantized in equidistant steps to account for the discrete black hole entropy. Here we shall show that loop quantum gravity, in which area is not quantized in equidistant steps can nevertheless be consistent with Bekenstein's equidistant entropy proposal in a subtle way. For that we perform a detailed analysis of the number of microstates compatible with a given area and show that an observed oscillatory behavior in the entropy-area relation, when properly interpreted yields an entropy that has discrete, equidistant values that are consistent with the Bekenstein framework.

  17. Branes and Quantization

    CERN Document Server

    Gukov, Sergei

    2008-01-01

    The problem of quantizing a symplectic manifold (M,\\omega) can be formulated in terms of the A-model of a complexification of M. This leads to an interesting new perspective on quantization. From this point of view, the Hilbert space obtained by quantization of (M,\\omega) is the space of (Bcc,B') strings, where Bcc and B' are two A-branes; B' is an ordinary Lagrangian A-brane, and Bcc is a space-filling coisotropic A-brane. B' is supported on M, and the choice of \\omega is encoded in the choice of Bcc. As an example, we describe from this point of view the representations of the group SL(2,R). Another application is to Chern-Simons gauge theory.

  18. Nonperturbative effects in deformation quantization

    CERN Document Server

    Periwal, V

    2000-01-01

    The Cattaneo-Felder path integral form of the perturbative Kontsevich deformation quantization formula is used to explicitly demonstrate the existence of nonperturbative corrections to na\\"\\i ve deformation quantization.

  19. A constrained joint source/channel coder design and vector quantization of nonstationary sources

    Science.gov (United States)

    Sayood, Khalid; Chen, Y. C.; Nori, S.; Araj, A.

    1993-01-01

    The emergence of broadband ISDN as the network for the future brings with it the promise of integration of all proposed services in a flexible environment. In order to achieve this flexibility, asynchronous transfer mode (ATM) has been proposed as the transfer technique. During this period a study was conducted on the bridging of network transmission performance and video coding. The successful transmission of variable bit rate video over ATM networks relies on the interaction between the video coding algorithm and the ATM networks. Two aspects of networks that determine the efficiency of video transmission are the resource allocation algorithm and the congestion control algorithm. These are explained in this report. Vector quantization (VQ) is one of the more popular compression techniques to appear in the last twenty years. Numerous compression techniques, which incorporate VQ, have been proposed. While the LBG VQ provides excellent compression, there are also several drawbacks to the use of the LBG quantizers including search complexity and memory requirements, and a mismatch between the codebook and the inputs. The latter mainly stems from the fact that the VQ is generally designed for a specific rate and a specific class of inputs. In this work, an adaptive technique is proposed for vector quantization of images and video sequences. This technique is an extension of the recursively indexed scalar quantization (RISQ) algorithm.

  20. A constrained joint source/channel coder design and vector quantization of nonstationary sources

    Science.gov (United States)

    Sayood, Khalid; Chen, Y. C.; Nori, S.; Araj, A.

    1993-12-01

    The emergence of broadband ISDN as the network for the future brings with it the promise of integration of all proposed services in a flexible environment. In order to achieve this flexibility, asynchronous transfer mode (ATM) has been proposed as the transfer technique. During this period a study was conducted on the bridging of network transmission performance and video coding. The successful transmission of variable bit rate video over ATM networks relies on the interaction between the video coding algorithm and the ATM networks. Two aspects of networks that determine the efficiency of video transmission are the resource allocation algorithm and the congestion control algorithm. These are explained in this report. Vector quantization (VQ) is one of the more popular compression techniques to appear in the last twenty years. Numerous compression techniques, which incorporate VQ, have been proposed. While the LBG VQ provides excellent compression, there are also several drawbacks to the use of the LBG quantizers including search complexity and memory requirements, and a mismatch between the codebook and the inputs. The latter mainly stems from the fact that the VQ is generally designed for a specific rate and a specific class of inputs. In this work, an adaptive technique is proposed for vector quantization of images and video sequences. This technique is an extension of the recursively indexed scalar quantization (RISQ) algorithm.

  1. Design and Analysis of LDGM-Based Codes for MSE Quantization

    CERN Document Server

    Wang, Qingchuan

    2008-01-01

    Approaching the 1.5329-dB shaping (granular) gain limit in mean-squared error (MSE) quantization of R^n is important in a number of problems, notably dirty-paper coding. For this purpose, we start with a binary low-density generator-matrix (LDGM) code, and construct the quantization codebook by periodically repeating its set of binary codewords, or them mapped to m-ary ones with Gray mapping. The quantization algorithm is based on belief propagation, and it uses a decimation procedure to do the guessing necessary for convergence. Using the results of a true typical decimator (TTD) as reference, it is shown that the asymptotic performance of the proposed quantizer can be characterized by certain monotonicity conditions on the code's fixed point properties, which can be analyzed with density evolution, and degree distribution optimization can be carried out accordingly. When the number of iterations is finite, the resulting loss is made amenable to analysis through the introduction of a recovery algorithm from ...

  2. Quantized, piecewise linear filter network

    DEFF Research Database (Denmark)

    Sørensen, John Aasted

    1993-01-01

    A quantization based piecewise linear filter network is defined. A method for the training of this network based on local approximation in the input space is devised. The training is carried out by repeatedly alternating between vector quantization of the training set into quantization classes an...

  3. Hopfion canonical quantization

    CERN Document Server

    Acus, A; Norvaisas, E; Shnir, Ya

    2012-01-01

    We study the effect of the canonical quantization of the rotational mode of the charge Q=1 and Q=2 spinning Hopfions. The axially-symmetric solutions are constructed numerically, it is shown the quantum corrections to the mass of the configurations are relatively large.

  4. Hopfion canonical quantization

    Energy Technology Data Exchange (ETDEWEB)

    Acus, A. [Vilnius University, Institute of Theoretical Physics and Astronomy, Gostauto 12, Vilnius 01108 (Lithuania); Halavanau, A. [Department of Theoretical Physics and Astrophysics, BSU, Minsk (Belarus); Norvaisas, E. [Vilnius University, Institute of Theoretical Physics and Astronomy, Gostauto 12, Vilnius 01108 (Lithuania); Shnir, Ya., E-mail: shnir@maths.tcd.ie [Department of Theoretical Physics and Astrophysics, BSU, Minsk (Belarus); Institute of Physics, Carl von Ossietzky University Oldenburg (Germany)

    2012-05-03

    We study the effect of the canonical quantization of the rotational mode of the charge Q=1 and Q=2 spinning Hopfions. The axially-symmetric solutions are constructed numerically, it is shown the quantum corrections to the mass of the configurations are relatively large.

  5. Quantized Algebra I Texts

    Science.gov (United States)

    DeBuvitz, William

    2014-01-01

    I am a volunteer reader at the Princeton unit of "Learning Ally" (formerly "Recording for the Blind & Dyslexic") and I recently discovered that high school students are introduced to the concept of quantization well before they take chemistry and physics. For the past few months I have been reading onto computer files a…

  6. Revisiting Canonical Quantization

    CERN Document Server

    Klauder, John R

    2012-01-01

    Conventional canonical quantization procedures directly link various c-number and q-number quantities. Here, we advocate a different association of classical and quantum quantities that renders classical theory a natural subset of quantum theory with \\hbar>0. While keeping the good results of conventional procedures, some examples are noted where the new procedures offer better results than conventional ones.

  7. SOFM网络在矢量量化的应用%Application of the SOFM Neural Network in Vector Quantization

    Institute of Scientific and Technical Information of China (English)

    李静; 富中华

    2015-01-01

    Vector quantization as a highly efficient data compression technology has been widely used in voice and image com⁃pression coding and transmission. The key problem of VQ is codebook design, because codebook has direct impacts on voice and video encoding quality. There are two serious shortcomings about the classic method LBG algorithm. It is sensitive to the initial codebook and training time is long. To solve these two problems, the text mainly research SOFM algorithm property and point of these two aspects, the result confirms that the codebook designed by SOFM network suffers small impact from the initial code book, and it can self-organized proceed study discipline, and have very strong adaptability. So we can see it well improved LBG algorithm's shortcomings in these two aspects.%矢量量化作为一种高效的数据压缩技术,在语音和图像的编码、传输中都有广泛的应用,其关键在于码书设计。码书的好坏直接影响语音、图像的编码质量。本文针对经典LBG算法对初始码书敏感及整体训练时间较长这两个缺陷,着重研究SOFM算法在这两方面的性质和特点,结果证实SOFM算法相对于LBG算法训练时间较短,且利用SOFM网络设计的码书受初始码书的影响小,具有很强的自适应性,很好的改善了LBG算法在这两方面的缺陷。

  8. National Household Education Survey, NHES: 91/93/95 Electronic Codebook (ECB) User's Guide.

    Science.gov (United States)

    Westat, Inc., Rockville, MD.

    The National Household Education Survey (NHES) CD-ROM for 1991, 1993, and 1995 contains an Electronic Codebook (ECB) program that allows the user to examine the variables in each of the NHES data sets easily and to create Statistical Analysis system and Statistical Package for the Social Sciences (for DOS or Windows) that will generate an extract…

  9. Performance Evaluation of Closed-Loop Spatial Multiplexing Codebook Based on Indoor MIMO Channel Measurement

    Directory of Open Access Journals (Sweden)

    Junjun Gao

    2012-01-01

    Full Text Available Closed-loop MIMO technique standardized in LTE can support different layer transmissions through precoding operation to match the channel multiplexing capability. However, the performance of the limited size codebook still needs to be evaluated in real channel environment for further insights. Based on the wideband MIMO channel measurement in a typical indoor scenario, capacity loss (CL of the limited size codebook relative to perfect precoding is studied first in two extreme channel conditions. The results show that current codebook design for single layer transmission is nearly capacity lossless, and the CL will increase with the number of transmitted layers. Furthermore, the capacity improvement of better codebook selection criterions is very limited compared to CL. Then we define the maximum capacity boost achieved by frequency domain layer adaption (FDLA and investigate its sensitivity to SNR and channel condition. To survey the effect of frequency domain channel variation on MIMO-OFDM system, we define a function to measure the fluctuation levels of the key channel metrics within a subband and reveal the inherent relationship between them. Finally, a capacity floor resulted as the feedback interval increases in frequency domain.

  10. Multi-Pitch Estimation of Audio Recordings Using a Codebook-Based Approach

    DEFF Research Database (Denmark)

    Hansen, Martin Weiss; Jensen, Jesper Rindom; Christensen, Mads Græsbøll

    2016-01-01

    ), and a codebook consisting of realistic amplitude vectors. A nonlinear least squares (NLS) cost function is formed based on the observed signal and a parametric model of the signal, for a set of fundamental frequency candidates. For each of these, amplitude estimates are computed. The magnitudes...

  11. Large-Scale Aerial Image Categorization Using a Multitask Topological Codebook.

    Science.gov (United States)

    Zhang, Luming; Wang, Meng; Hong, Richang; Yin, Bao-Cai; Li, Xuelong

    2016-02-01

    Fast and accurately categorizing the millions of aerial images on Google Maps is a useful technique in pattern recognition. Existing methods cannot handle this task successfully due to two reasons: 1) the aerial images' topologies are the key feature to distinguish their categories, but they cannot be effectively encoded by a conventional visual codebook and 2) it is challenging to build a realtime image categorization system, as some geo-aware Apps update over 20 aerial images per second. To solve these problems, we propose an efficient aerial image categorization algorithm. It focuses on learning a discriminative topological codebook of aerial images under a multitask learning framework. The pipeline can be summarized as follows. We first construct a region adjacency graph (RAG) that describes the topology of each aerial image. Naturally, aerial image categorization can be formulated as RAG-to-RAG matching. According to graph theory, RAG-to-RAG matching is conducted by enumeratively comparing all their respective graphlets (i.e., small subgraphs). To alleviate the high time consumption, we propose to learn a codebook containing topologies jointly discriminative to multiple categories. The learned topological codebook guides the extraction of the discriminative graphlets. Finally, these graphlets are integrated into an AdaBoost model for predicting aerial image categories. Experimental results show that our approach is competitive to several existing recognition models. Furthermore, over 24 aerial images are processed per second, demonstrating that our approach is ready for real-world applications.

  12. Comparison of different quantization strategies for subband coding of medical images

    Science.gov (United States)

    Castagno, Roberto; Lancini, Rosa C.; Egger, Olivier

    1996-04-01

    computationally demanding training procedure in order to produce a codebook. The second group represents an interesting alternative, based on the multidimensional properties of the distribution of the source to code. In particular a pyramid vector quantization has been taken into account. Despite being based on the implicit geometry of independent and identically distributed (i.i.d.) Laplacian sources, this method proved to achieve good results with other distributions. Tests show that zerotree yields the most promising results in the rate- distortion sense. Moreover, this approach allows an exact rate control and has the possibility of a progressive bitstream which can be used either for data browsing or up to a lossless representation of the input image.

  13. BRST quantization of cosmological perturbations

    Energy Technology Data Exchange (ETDEWEB)

    Armendariz-Picon, Cristian [Physics Department, St. Lawrence University,Canton, NY 13617 (United States); Şengör, Gizem [Department of Physics, Syracuse University,Syracuse, NY 13244 (United States)

    2016-11-08

    BRST quantization is an elegant and powerful method to quantize theories with local symmetries. In this article we study the Hamiltonian BRST quantization of cosmological perturbations in a universe dominated by a scalar field, along with the closely related quantization method of Dirac. We describe how both formalisms apply to perturbations in a time-dependent background, and how expectation values of gauge-invariant operators can be calculated in the in-in formalism. Our analysis focuses mostly on the free theory. By appropriate canonical transformations we simplify and diagonalize the free Hamiltonian. BRST quantization in derivative gauges allows us to dramatically simplify the structure of the propagators, whereas Dirac quantization, which amounts to quantization in synchronous gauge, dispenses with the need to introduce ghosts and preserves the locality of the gauge-fixed action.

  14. BRST Quantization of Cosmological Perturbations

    CERN Document Server

    Armendariz-Picon, Cristian

    2016-01-01

    BRST quantization is an elegant and powerful method to quantize theories with local symmetries. In this article we study the Hamiltonian BRST quantization of cosmological perturbations in a universe dominated by a scalar field, along with the closely related quantization method of Dirac. We describe how both formalisms apply to the perturbations in a time-dependent background, and how expectation values of gauge-invariant operators can be calculated in the in-in formalism. Our analysis focuses mostly on the free theory. By appropriate canonical transformations we simplify and diagonalize the free Hamiltonian. BRST quantization in derivative gauges allows us to dramatically simplify the structure of the propagators, whereas quantization in synchronous gauge, which amounts to Dirac quantization, dispenses with the need to introduce ghosts and preserves the locality of the gauge-fixed action.

  15. Deformation quantization and Nambu mechanics

    CERN Document Server

    Dito, G; Sternheimer, D; Takhtajan, L A; Dito, Giuseppe; Flato, Moshe; Sternheimer, Daniel; Takhtajan, Leon

    1996-01-01

    Starting from deformation quantization (star-products), the quantization problem of Nambu Mechanics is investigated. After considering some impossibilities and pushing some analogies with field quantization, a solution to the quantization problem is presented in what we call the Zariski quantization of fields (observables, functions, in this case polynomials). This quantization is based on the factorization over {\\Bbb R} of polynomials in several real variables. We quantize the algebra of fields generated by the polynomials by defining a deformation of this algebra which is Abelian, associative and distributive. This procedure is then adapted to derivatives (needed for the Nambu brackets), which ensures the validity of the Fundamental Identity of Nambu Mechanics also at the quantum level. Our construction is in fact more general than the particular case considered here: it can be utilized for quite general defining identities and for much more general star-products.

  16. Uniform quantized electron gas

    Science.gov (United States)

    Høye, Johan S.; Lomba, Enrique

    2016-10-01

    In this work we study the correlation energy of the quantized electron gas of uniform density at temperature T  =  0. To do so we utilize methods from classical statistical mechanics. The basis for this is the Feynman path integral for the partition function of quantized systems. With this representation the quantum mechanical problem can be interpreted as, and is equivalent to, a classical polymer problem in four dimensions where the fourth dimension is imaginary time. Thus methods, results, and properties obtained in the statistical mechanics of classical fluids can be utilized. From this viewpoint we recover the well known RPA (random phase approximation). Then to improve it we modify the RPA by requiring the corresponding correlation function to be such that electrons with equal spins can not be on the same position. Numerical evaluations are compared with well known results of a standard parameterization of Monte Carlo correlation energies.

  17. Resurgence matches quantization

    Science.gov (United States)

    Couso-Santamaría, Ricardo; Mariño, Marcos; Schiappa, Ricardo

    2017-04-01

    The quest to find a nonperturbative formulation of topological string theory has recently seen two unrelated developments. On the one hand, via quantization of the mirror curve associated to a toric Calabi–Yau background, it has been possible to give a nonperturbative definition of the topological-string partition function. On the other hand, using techniques of resurgence and transseries, it has been possible to extend the string (asymptotic) perturbative expansion into a transseries involving nonperturbative instanton sectors. Within the specific example of the local {{{P}}2} toric Calabi–Yau threefold, the present work shows how the Borel–Padé–Écalle resummation of this resurgent transseries, alongside occurrence of Stokes phenomenon, matches the string-theoretic partition function obtained via quantization of the mirror curve. This match is highly non-trivial, given the unrelated nature of both nonperturbative frameworks, signaling at the existence of a consistent underlying structure.

  18. Improved Lattice Radial Quantization

    CERN Document Server

    Brower, Richard C; Fleming, George T

    2014-01-01

    Lattice radial quantization was proposed in a recent paper by Brower, Fleming and Neuberger[1] as a nonperturbative method especially suited to numerically solve Euclidean conformal field theories. The lessons learned from the lattice radial quantization of the 3D Ising model on a longitudinal cylinder with 2D Icosahedral cross-section suggested the need for an improved discretization. We consider here the use of the Finite Element Methods(FEM) to descretize the universally-equivalent $\\phi^4$ Lagrangian on $\\mathbb R \\times \\mathbb S^2$. It is argued that this lattice regularization will approach the exact conformal theory at the Wilson-Fisher fixed point in the continuum. Numerical tests are underway to support this conjecture.

  19. Resurgence Matches Quantization

    CERN Document Server

    Couso-Santamaría, Ricardo; Schiappa, Ricardo

    2016-01-01

    The quest to find a nonperturbative formulation of topological string theory has recently seen two unrelated developments. On the one hand, via quantization of the mirror curve associated to a toric Calabi-Yau background, it has been possible to give a nonperturbative definition of the topological-string partition function. On the other hand, using techniques of resurgence and transseries, it has been possible to extend the string (asymptotic) perturbative expansion into a transseries involving nonperturbative instanton sectors. Within the specific example of the local P2 toric Calabi-Yau threefold, the present work shows how the Borel-Pade-Ecalle resummation of this resurgent transseries, alongside occurrence of Stokes phenomenon, matches the string-theoretic partition function obtained via quantization of the mirror curve. This match is highly non-trivial, given the unrelated nature of both nonperturbative frameworks, signaling at the existence of a consistent underlying structure.

  20. WAVELET SCALAR QUANTIZATION

    Directory of Open Access Journals (Sweden)

    B.Karuna kumar

    2009-09-01

    Full Text Available Fingerprints are today the most widely used biometric features for personal identification. With the increasing usage of biometric systems the question arises naturally how to store and handle the acquired sensor data. Our algorithm for the digitized images is based on adaptive uniform scalar quantization of discrete wavelet transform sub band decomposition. This technique referred to as the wavelet scalar quantization method. The algorithm produces archival quality images at compression ratios of around 15 to 1 and will allow the current database of paper finger print cards to be replaced by digital imagery. A compliance testing program is also being implemented to ensure high standards of image quality and interchangeability of data between different implementations.

  1. Analysis of quantization noise and state estimation with quantized measurements

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    The approximate correction of the additive white noise model in quantized Kalman filter is investigated under certain conditions. The probability density function of the error of quantized measurements is analyzed theoretically and experimentally. The analysis is based on the probability theory and nonparametric density estimation technique, respectively. The approximator of probability density function of quantized measurement noise is given. The numerical results of nonparametric density estimation algori...

  2. Quantization Procedures; Sistemas de cuantificacion

    Energy Technology Data Exchange (ETDEWEB)

    Cabrera, J. A.; Martin, R.

    1976-07-01

    We present in this work a review of the conventional quantization procedure, the proposed by I.E. Segal and a new quantization procedure similar to this one for use in non linear problems. We apply this quantization procedures to different potentials and we obtain the appropriate equations of motion. It is shown that for the linear case the three procedures exposed are equivalent but for the non linear cases we obtain different equations of motion and different energy spectra. (Author) 16 refs.

  3. System Identification with Quantized Observations

    CERN Document Server

    Wang, Le Yi; Zhang, Jifeng; Zhao, Yanlong

    2010-01-01

    This book presents recently developed methodologies that utilize quantized information in system identification and explores their potential in extending control capabilities for systems with limited sensor information or networked systems. The results of these methodologies can be applied to signal processing and control design of communication and computer networks, sensor networks, mobile agents, coordinated data fusion, remote sensing, telemedicine, and other fields in which noise-corrupted quantized data need to be processed. Providing a comprehensive coverage of quantized identification,

  4. Detection and Demarcation of Tumor using Vector Quantization in MRI images

    CERN Document Server

    Kekre, H B; Gharge, Saylee M

    2010-01-01

    Segmenting a MRI images into homogeneous texture regions representing disparate tissue types is often a useful preprocessing step in the computer-assisted detection of breast cancer. That is why we proposed new algorithm to detect cancer in mammogram breast cancer images. In this paper we proposed segmentation using vector quantization technique. Here we used Linde Buzo-Gray algorithm (LBG) for segmentation of MRI images. Initially a codebook of size 128 was generated for MRI images. These code vectors were further clustered in 8 clusters using same LBG algorithm. These 8 images were displayed as a result. This approach does not leads to over segmentation or under segmentation. For the comparison purpose we displayed results of watershed segmentation and Entropy using Gray Level Co-occurrence Matrix along with this method.

  5. Vehicle detection algorithm based on codebook and local binary patterns algorithms

    Institute of Scientific and Technical Information of China (English)

    许雪梅; 周立超; 墨芹; 郭巧云

    2015-01-01

    Detecting the moving vehicles in jittering traffic scenes is a very difficult problem because of the complex environment. Only by the color features of the pixel or only by the texture features of image cannot establish a suitable background model for the moving vehicles. In order to solve this problem, the Gaussian pyramid layered algorithm is proposed, combining with the advantages of the Codebook algorithm and the Local binary patterns (LBP) algorithm. Firstly, the image pyramid is established to eliminate the noises generated by the camera shake. Then, codebook model and LBP model are constructed on the low-resolution level and the high-resolution level of Gaussian pyramid, respectively. At last, the final test results are obtained through a set of operations according to the spatial relations of pixels. The experimental results show that this algorithm can not only eliminate the noises effectively, but also save the calculating time with high detection sensitivity and high detection accuracy.

  6. Round Randomized Learning Vector Quantization for Brain Tumor Imaging

    Directory of Open Access Journals (Sweden)

    Siti Norul Huda Sheikh Abdullah

    2016-01-01

    Full Text Available Brain magnetic resonance imaging (MRI classification into normal and abnormal is a critical and challenging task. Owing to that, several medical imaging classification techniques have been devised in which Learning Vector Quantization (LVQ is amongst the potential. The main goal of this paper is to enhance the performance of LVQ technique in order to gain higher accuracy detection for brain tumor in MRIs. The classical way of selecting the winner code vector in LVQ is to measure the distance between the input vector and the codebook vectors using Euclidean distance function. In order to improve the winner selection technique, round off function is employed along with the Euclidean distance function. Moreover, in competitive learning classifiers, the fitting model is highly dependent on the class distribution. Therefore this paper proposed a multiresampling technique for which better class distribution can be achieved. This multiresampling is executed by using random selection via preclassification. The test data sample used are the brain tumor magnetic resonance images collected from Universiti Kebangsaan Malaysia Medical Center and UCI benchmark data sets. Comparative studies showed that the proposed methods with promising results are LVQ1, Multipass LVQ, Hierarchical LVQ, Multilayer Perceptron, and Radial Basis Function.

  7. Quantization of interface currents

    Energy Technology Data Exchange (ETDEWEB)

    Kotani, Motoko [AIMR, Tohoku University, Sendai (Japan); Schulz-Baldes, Hermann [Department Mathematik, Universität Erlangen-Nürnberg, Erlangen (Germany); Villegas-Blas, Carlos [Instituto de Matematicas, Cuernavaca, UNAM, Cuernavaca (Mexico)

    2014-12-15

    At the interface of two two-dimensional quantum systems, there may exist interface currents similar to edge currents in quantum Hall systems. It is proved that these interface currents are macroscopically quantized by an integer that is given by the difference of the Chern numbers of the two systems. It is also argued that at the interface between two time-reversal invariant systems with half-integer spin, one of which is trivial and the other non-trivial, there are dissipationless spin-polarized interface currents.

  8. Quantization of submanifold embeddings

    Energy Technology Data Exchange (ETDEWEB)

    Bahns, Dorothea; Zahn, Jochen [Courant Research Centre ' ' Higher Order Structures' ' , Universitaet Goettingen (Germany); Rejzner, Katarzyna [II. Institut fuer Theoretische Physik, Universitaet Hamburg (Germany)

    2013-07-01

    We describe a perturbative quantization of the embedding of d-dimensional submanifolds into n-dimensional Minkowski space, based on suitable generalizations of the Nambu-Goto action. We use tools from perturbative algebraic quantum field theory, quantum field theory on curved spacetimes, and the Batalin-Vilkovisky formalism. The resulting theory is perturbatively non-renormalizable, but well-defined as an effective theory, i.e., there are no anomalies, for any dimension d,n. In particular there is no critical dimension for the case of string theory (d=2).

  9. Generalized Superfield Lagrangian Quantization

    CERN Document Server

    Lavrov, P M; Moshin, P Y

    2002-01-01

    We consider an extension of the gauge-fixing procedure in the framework of the Lagrangian superfield BRST and BRST-antiBRST quantization schemes for arbitrary gauge theories, taking into account the possible ambiguity in the choice of the superfield antibracket. We show that this ambiguity is fixed by the algebraic properties of the antibracket and the form of the BRST and antiBRST transformations, realized in terms of superspace translations. The Ward identities related to the generalized gauge-fixing procedure are obtained.

  10. Quantizing Earth surface deformations

    Directory of Open Access Journals (Sweden)

    C. O. Bowin

    2015-03-01

    Full Text Available The global analysis of Bowin (2010 used the global 14 absolute Euler pole set (62 Myr history from Gripp and Gordon (1990 and demonstrated that plate tectonics conserves angular momentum. We herein extend that analysis using the more detailed Bird (2003 52 present-day Euler pole set (relative to a fixed Pacific plate for the Earth's surface, after conversion to absolute Euler poles. Additionally, new analytical results now provide new details on upper mantle mass anomalies in the outer 200 km of the Earth, as well as an initial quantizing of surface deformations.

  11. Optimization of frequency quantization

    CERN Document Server

    Tibabishev, V N

    2011-01-01

    We obtain the functional defining the price and quality of sample readings of the generalized velocities. It is shown that the optimal sampling frequency, in the sense of minimizing the functional quality and price depends on the sampling of the upper cutoff frequency of the analog signal of the order of the generalized velocities measured by the generalized coordinates, the frequency properties of the analog input filter and a maximum sampling rate for analog-digital converter (ADC). An example of calculating the frequency quantization for two-tier ADC with an input RC filter.

  12. Covariant Quantization with Extended BRST Symmetry

    CERN Document Server

    Geyer, B; Lavrov, P M

    1999-01-01

    A short rewiev of covariant quantization methods based on BRST-antiBRST symmetry is given. In particular problems of correct definition of Sp(2) symmetric quantization scheme known as triplectic quantization are considered.

  13. Quantization Of Temperature

    Science.gov (United States)

    O'Brien, Paul

    2017-01-01

    Max Plank did not quantize temperature. I will show that the Plank temperature violates the Plank scale. Plank stated that the Plank scale was Natures scale and independent of human construct. Also stating that even aliens would derive the same values. He made a huge mistake, because temperature is based on the Kelvin scale, which is man-made just like the meter and kilogram. He did not discover natures scale for the quantization of temperature. His formula is flawed, and his value is incorrect. Plank's calculation is Tp = c2Mp/Kb. The general form of this equation is T = E/Kb Why is this wrong? The temperature for a fixed amount of energy is dependent upon the volume it occupies. Using the correct formula involves specifying the radius of the volume in the form of (RE). This leads to an inequality and a limit that is equivalent to the Bekenstein Bound, but using temperature instead of entropy. Rewriting this equation as a limit defines both the maximum temperature and Boltzmann's constant. This will saturate any space-time boundary with maximum temperature and information density, also the minimum radius and entropy. The general form of the equation then becomes a limit in BH thermodynamics T <= (RE)/(λKb) .

  14. Coherent state quantization of quaternions

    Energy Technology Data Exchange (ETDEWEB)

    Muraleetharan, B., E-mail: bbmuraleetharan@jfn.ac.lk, E-mail: santhar@gmail.com [Department of Mathematics and Statistics, University of Jaffna, Thirunelveli (Sri Lanka); Thirulogasanthar, K., E-mail: bbmuraleetharan@jfn.ac.lk, E-mail: santhar@gmail.com [Department of Computer Science and Software Engineering, Concordia University, 1455 De Maisonneuve Blvd. West, Montreal, Quebec H3G 1M8 (Canada)

    2015-08-15

    Parallel to the quantization of the complex plane, using the canonical coherent states of a right quaternionic Hilbert space, quaternion field of quaternionic quantum mechanics is quantized. Associated upper symbols, lower symbols, and related quantities are analyzed. Quaternionic version of the harmonic oscillator and Weyl-Heisenberg algebra are also obtained.

  15. Quantization over boson operator spaces

    Energy Technology Data Exchange (ETDEWEB)

    Prosen, Tomaz [Department of Physics, FMF, University of Ljubljana, Ljubljana (Slovenia); Seligman, Thomas H [Instituto de Ciencias FIsicas, Universidad Nacional Autonoma de Mexico, Cuernavaca, Morelos (Mexico)

    2010-10-01

    The framework of third quantization-canonical quantization in the Liouville space-is developed for open many-body bosonic systems. We show how to diagonalize the quantum Liouvillean for an arbitrary quadratic n-boson Hamiltonian with arbitrary linear Lindblad couplings to the baths and, as an example, explicitly work out a general case of a single boson. (fast track communication)

  16. Quantization over boson operator spaces

    CERN Document Server

    Prosen, Tomaz

    2010-01-01

    The framework of third quantization - canonical quantization in the Liouville space - is developed for open many-body bosonic systems. We show how to diagonalize the quantum Liouvillean for an arbitrary quadratic n-boson Hamiltonian with arbitrary linear Lindblad couplings to the baths and, as an example, explicitly work out a general case of a single boson.

  17. Matrix Quantization of Turbulence

    CERN Document Server

    Floratos, Emmanuel

    2011-01-01

    Based on our recent work on Quantum Nambu Mechanics $\\cite{af2}$, we provide an explicit quantization of the Lorenz chaotic attractor through the introduction of Non-commutative phase space coordinates as Hermitian $ N \\times N $ matrices in $ R^{3}$. For the volume preserving part, they satisfy the commutation relations induced by one of the two Nambu Hamiltonians, the second one generating a unique time evolution. Dissipation is incorporated quantum mechanically in a self-consistent way having the correct classical limit without the introduction of external degrees of freedom. Due to its volume phase space contraction it violates the quantum commutation relations. We demonstrate that the Heisenberg-Nambu evolution equations for the Matrix Lorenz system develop fast decoherence to N independent Lorenz attractors. On the other hand there is a weak dissipation regime, where the quantum mechanical properties of the volume preserving non-dissipative sector survive for long times.

  18. Second Quantized Mathieu Moonshine

    CERN Document Server

    Persson, Daniel

    2013-01-01

    We study the second quantized version of the twisted twining genera of generalized Mathieu moonshine, and verify that they give rise to Siegel modular forms with infinite product representations. Most of these forms are expected to have an interpretation as twisted partition functions counting 1/4 BPS dyons in type II superstring theory on K3\\times T^2 or in heterotic CHL-models. We show that all these Siegel modular forms, independently of their possible physical interpretation, satisfy an "S-duality" transformation and a "wall-crossing formula". The latter reproduces all the eta-products of an older version of generalized Mathieu moonshine proposed by Mason in the '90s. Surprisingly, some of the Siegel modular forms we find coincide with the multiplicative (Borcherds) lifts of Jacobi forms in umbral moonshine.

  19. Quantized beam shifts in graphene

    Energy Technology Data Exchange (ETDEWEB)

    de Melo Kort-Kamp, Wilton Junior [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Sinitsyn, Nikolai [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Dalvit, Diego Alejandro Roberto [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2015-10-08

    We predict the existence of quantized Imbert-Fedorov, Goos-Hanchen, and photonic spin Hall shifts for light beams impinging on a graphene-on-substrate system in an external magnetic field. In the quantum Hall regime the Imbert-Fedorov and photonic spin Hall shifts are quantized in integer multiples of the fine structure constant α, while the Goos-Hanchen ones in multiples of α2. We investigate the influence on these shifts of magnetic field, temperature, and material dispersion and dissipation. An experimental demonstration of quantized beam shifts could be achieved at terahertz frequencies for moderate values of the magnetic field.

  20. VLSI Processor For Vector Quantization

    Science.gov (United States)

    Tawel, Raoul

    1995-01-01

    Pixel intensities in each kernel compared simultaneously with all code vectors. Prototype high-performance, low-power, very-large-scale integrated (VLSI) circuit designed to perform compression of image data by vector-quantization method. Contains relatively simple analog computational cells operating on direct or buffered outputs of photodetectors grouped into blocks in imaging array, yielding vector-quantization code word for each such block in sequence. Scheme exploits parallel-processing nature of vector-quantization architecture, with consequent increase in speed.

  1. Quantization Ambiguity, Ergodicity and Semiclassics

    CERN Document Server

    Kaplan, L

    1999-01-01

    A simple argument shows that eigenstates of a classically ergodic system are individually ergodic on coarse-grained scales. This has implications for the quantization ambiguity in ergodic systems: the difference between alternative quantizations is suppressed compared with the $O(\\hbar^2)$ ambiguity in the integrable case. For two-dimensional ergodic systems in the high-energy regime, individual eigenstates are independent of the choice of quantization procedure, in contrast with the regular case, where even the ordering of eigenlevels is ambiguous. Surprisingly, semiclassical methods are shown to be much more precise for chaotic than for integrable systems.

  2. Quantization ambiguity, ergodicity and semiclassics

    Energy Technology Data Exchange (ETDEWEB)

    Kaplan, Lev [Institute for Nuclear Theory, University of Washington, Seattle, WA (United States)

    2002-11-01

    It is well known that almost all eigenstates of a classically ergodic system are individually ergodic on coarse-grained scales. This has important implications for the quantization ambiguity in ergodic systems: the difference between alternative quantizations is suppressed compared with the O( h-bar {sup 2}) ambiguity in the integrable or regular case. For two-dimensional ergodic systems in the high-energy regime, individual eigenstates are independent of the choice of quantization procedure, in contrast with the regular case, where even the ordering of eigenlevels is ambiguous. Surprisingly, semiclassical methods are shown to be much more precise in any dimension for chaotic than for integrable systems.

  3. Image quantization: statistics and modeling

    Science.gov (United States)

    Whiting, Bruce R.; Muka, Edward

    1998-07-01

    A method for analyzing the effects of quantization, developed for temporal one-dimensional signals, is extended to two- dimensional radiographic images. By calculating the probability density function for the second order statistics (the differences between nearest neighbor pixels) and utilizing its Fourier transform (the characteristic function), the effect of quantization on image statistics can be studied by the use of standard communication theory. The approach is demonstrated by characterizing the noise properties of a storage phosphor computed radiography system and the image statistics of a simple radiographic object (cylinder) and by comparing the model to experimental measurements. The role of quantization noise and the onset of contouring in image degradation are explained.

  4. Lattice radial quantization by cubature

    CERN Document Server

    Neuberger, Herbert

    2014-01-01

    Basic aspects of a program to put field theories quantized in radial coordinates on the lattice are presented. Only scalar fields are discussed. Simple examples are solved to illustrate the strategy when applied to the 3D Ising model.

  5. Feedback Quantization in Crosscorrelation Predistorters

    NARCIS (Netherlands)

    Kokkeler, Andre B.J.

    2005-01-01

    Amplification of signals with fluctuating envelopes inevitably leads to distortion because of nonlinear behavior of the power amplifier (PA). Digital predistortion can counteract these nonlinear effects. In this letter, the crosscorrelation predistorter is described and the effects of quantization i

  6. Canonical quantization of constrained systems

    Energy Technology Data Exchange (ETDEWEB)

    Bouzas, A.; Epele, L.N.; Fanchiotti, H.; Canal, C.A.G. (Laboratorio de Fisica Teorica, Departamento de Fisica, Universidad Nacional de La Plata, Casilla de Correo No. 67, 1900 La Plata, Argentina (AR))

    1990-07-01

    The consideration of first-class constraints together with gauge conditions as a set of second-class constraints in a given system is shown to be incorrect when carrying out its canonical quantization.

  7. Canonical quantization of macroscopic electromagnetism

    Energy Technology Data Exchange (ETDEWEB)

    Philbin, T G, E-mail: tgp3@st-andrews.ac.u [School of Physics and Astronomy, University of St Andrews, North Haugh, St Andrews, Fife KY16 9SS (United Kingdom)

    2010-12-15

    Application of the standard canonical quantization rules of quantum field theory to macroscopic electromagnetism has encountered obstacles due to material dispersion and absorption. This has led to a phenomenological approach to macroscopic quantum electrodynamics where no canonical formulation is attempted. In this paper macroscopic electromagnetism is canonically quantized. The results apply to any linear, inhomogeneous, magnetodielectric medium with dielectric functions that obey the Kramers-Kronig relations. The prescriptions of the phenomenological approach are derived from the canonical theory.

  8. Canonical quantization of macroscopic electromagnetism

    CERN Document Server

    Philbin, T G

    2010-01-01

    Application of the standard canonical quantization rules of quantum field theory to macroscopic electromagnetism has encountered obstacles due to material dispersion and absorption. This has led to a phenomenological approach to macroscopic quantum electrodynamics where no canonical formulation is attempted. In this paper macroscopic electromagnetism is canonically quantized. The results apply to any linear, inhomogeneous, magnetoelectric medium with dielectric functions that obey the Kramers-Kronig relations. The prescriptions of the phenomenological approach are derived from the canonical theory.

  9. The quantized D-transformation.

    Science.gov (United States)

    Saraceno, M.; Vallejos, R. O.

    1996-06-01

    We construct a new example of a quantum map, the quantized version of the D-transformation, which is the natural extension to two dimensions of the tent map. The classical, quantum and semiclassical behavior is studied. We also exhibit some relationships between the quantum versions of the D-map and the parity projected baker's map. The method of construction allows a generalization to dissipative maps which includes the quantization of a horseshoe. (c) 1996 American Institute of Physics.

  10. Quantized Visual Awareness

    Directory of Open Access Journals (Sweden)

    W Alexander Escobar

    2013-11-01

    Full Text Available The proposed model holds that, at its most fundamental level, visual awareness is quantized. That is to say that visual awareness arises as individual bits of awareness through the action of neural circuits with hundreds to thousands of neurons in at least the human striate cortex. Circuits with specific topologies will reproducibly result in visual awareness that correspond to basic aspects of vision like color, motion and depth. These quanta of awareness (qualia are produced by the feedforward sweep that occurs through the geniculocortical pathway but are not integrated into a conscious experience until recurrent processing from centers like V4 or V5 select the appropriate qualia being produced in V1 to create a percept. The model proposed here has the potential to shift the focus of the search for visual awareness to the level of microcircuits and these likely exist across the kingdom Animalia. Thus establishing qualia as the fundamental nature of visual awareness will not only provide a deeper understanding of awareness, but also allow for a more quantitative understanding of the evolution of visual awareness throughout the animal kingdom.

  11. Enhanced codebook algorithm for fast moving object detection from dynamic background using scene visual perception

    Science.gov (United States)

    Mousse, Mikaël A.; Motamed, Cina; Ezin, Eugène C.

    2016-11-01

    The detection of moving objects in a video sequence is the first step in an automatic video surveillance system. This work proposes an enhancement of a codebook-based algorithm for moving objects extraction. The proposed algorithm used a perceptual-based approach to optimize foreground information extraction complexity by using a modified codebook algorithm. The purpose of the adaptive strategy is to reduce the computational complexity of the foreground detection algorithm while maintaining its global accuracy. In this algorithm, we use a superpixels segmentation approach to model the spatial dependencies between pixels. The processing of the superpixels is controlled to focus it on the superpixels that are near to the possible location of foreground objects. The performance of the proposed algorithm is evaluated and compared to other algorithms of the state of the art using a public dataset that proposes sequences with a dynamic background. Experimental results prove that the proposed algorithm obtained the best the frame processing rate during the foreground detection.

  12. NHES:91/93/95/96 Electronic CodeBook (ECB) User's Guide. National Household Education Survey.

    Science.gov (United States)

    Collins, Mary A.; Chandler, Kathryn

    The National Household Education Survey (NHES) is a random digit dial telephone survey of households developed by the National Center for Education Statistics. It has been conducted in 1991, 1993, 1995, and 1996, with varying components each year. The NHES 91/93/95/96 CD-ROM contains an electronic codebook (ECB) program that, after being installed…

  13. Spin Foams and Canonical Quantization

    CERN Document Server

    Alexandrov, Sergei; Noui, Karim

    2011-01-01

    This review is devoted to the analysis of the mutual consistency of the spin foam and canonical loop quantizations in three and four spacetime dimensions. In the three-dimensional context, where the two approaches are in good agreement, we show how the canonical quantization \\`a la Witten of Riemannian gravity with a positive cosmological constant is related to the Turaev-Viro spin foam model, and how the Ponzano-Regge amplitudes are related to the physical scalar product of Riemannian loop quantum gravity without cosmological constant. In the four-dimensional case, we recall a Lorentz-covariant formulation of loop quantum gravity using projected spin networks, compare it with the new spin foam models, and identify interesting relations and their pitfalls. Finally, we discuss the properties which a spin foam model is expected to possess in order to be consistent with the canonical quantization, and suggest a new model illustrating these results.

  14. There is no "First" Quantization

    CERN Document Server

    Zeh, H D

    2003-01-01

    The appearance of spinor fields as operators or arguments of field functionals in quantum field theory is often regarded as a second quantization, since fermion wave functions were themselves discovered by quantizing mass points (``particles''). I argue that this language, though reflecting the historical development, is misleading. Field amplitudes always represent the true physical variables (in quantum theory the arguments of a fundamental wave functional), including fields which never appear classical, while apparent particles are no more than the result of decoherence in the measuring device, without playing any fundamental role in the theory or its interpretation. A remark on gauge fields is added.

  15. EZW coding using nonuniform quantization

    Science.gov (United States)

    Yin, Che-Yi; Derin, Haluk

    1999-10-01

    This paper presents an image coder that modifies the EZW coder and provides an improvement in its performance. The subband EZW image coder uses a uniform quantizer with a threshold (deadzone). Whereas, we know that the distribution/histogram of the wavelet tree subband coefficients, all except the lowest subband, tend to be Laplacian. To accommodate for this, we modify the refining procedure in EZW and use a non-uniform quantizer on the coefficients that better fits their distribution. The experimental results show that the new image coder performs better than EZW.

  16. Periodic roads and quantized wheels

    Science.gov (United States)

    de Campos Valadares, Eduardo

    2016-08-01

    We propose a simple approach to determine all possible wheels that can roll smoothly without slipping on a periodic roadbed, while maintaining the center of mass at a fixed height. We also address the inverse problem that of obtaining the roadbed profile compatible with a specific wheel and all other related "quantized wheels." The role of symmetry is highlighted, which might preclude the center of mass from remaining at a fixed height. A straightforward consequence of such geometric quantization is that the gravitational potential energy and the moment of inertia are discrete, suggesting a parallelism between macroscopic wheels and nano-systems, such as carbon nanotubes.

  17. Quantization on nilpotent Lie groups

    CERN Document Server

    Fischer, Veronique

    2016-01-01

    This book presents a consistent development of the Kohn-Nirenberg type global quantization theory in the setting of graded nilpotent Lie groups in terms of their representations. It contains a detailed exposition of related background topics on homogeneous Lie groups, nilpotent Lie groups, and the analysis of Rockland operators on graded Lie groups together with their associated Sobolev spaces. For the specific example of the Heisenberg group the theory is illustrated in detail. In addition, the book features a brief account of the corresponding quantization theory in the setting of compact Lie groups. The monograph is the winner of the 2014 Ferran Sunyer i Balaguer Prize.

  18. What is "Relativistic Canonical Quantization"?

    OpenAIRE

    Arbatsky, D. A.

    2005-01-01

    The purpose of this review is to give the most popular description of the scheme of quantization of relativistic fields that was named relativistic canonical quantization (RCQ). I do not give here the full exact account of this scheme. But with the help of this review any physicist, even not a specialist in the relativistic quantum theory, will be able to get a general view of the content of RCQ, of its connection with other known approaches, of its novelty and of its fruitfulness.

  19. Enhanced Quantization: The particle on the circle

    CERN Document Server

    Geloun, Joseph Ben

    2012-01-01

    Enhanced quantization is an improved program for overcoming difficulties which may arise during an ordinary canonical quantization procedure. We review here how this program applies for a particle on circle.

  20. Superfield Covariant Quantization with BRST Symmetry

    CERN Document Server

    Lavrov, P M

    2000-01-01

    We generalize the method of superfield Lagrangian BRST quantization in the part of the gauge-fixing procedure and obtain a quantization method that can be considered as an alternative to the Batalin - Vilkovisky formalism.

  1. Plausible Explanation of Quantization of Intrinsic Redshift from Hall Effect and Weyl Quantization

    Directory of Open Access Journals (Sweden)

    Smarandache F.

    2006-10-01

    Full Text Available Using phion condensate model as described by Moffat [1], we consider a plausible explanation of (Tifft intrinsic redshift quantization as described by Bell [6] as result of Hall effect in rotating frame. We also discuss another alternative to explain redshift quantization from the viewpoint of Weyl quantization, which could yield Bohr- Sommerfeld quantization.

  2. Context quantization by minimum adaptive code length

    DEFF Research Database (Denmark)

    Forchhammer, Søren; Wu, Xiaolin

    2007-01-01

    Context quantization is a technique to deal with the issue of context dilution in high-order conditional entropy coding. We investigate the problem of context quantizer design under the criterion of minimum adaptive code length. A property of such context quantizers is derived for binary symbols...

  3. Phase transitions in Vector Quantization

    NARCIS (Netherlands)

    Witoelar, Aree; Ghosh, Anarta; Biehl, Michael; Verleysen, Michel

    2008-01-01

    We study Winner-Takes-All and rank based Vector Quantization along the lines of the statistical physics of off-line learning. Typical behavior of the system is obtained within a model where high-dimensional training data are drawn from a mixture of Gaussians. The analysis becomes exact in the simpli

  4. Quantization of Second Order Fermions

    Energy Technology Data Exchange (ETDEWEB)

    Angeles, Rene; Napsuciale, Mauro, E-mail: rene@fisica.ugto.mx, E-mail: mauro@fisica.ugto.mx [Departamento de Fisica, Universidad de Guanajuato, Lomas del Bosque 103, Fraccionamiento Lomas del Campestre, Leon Guanajuato, 37150 (Mexico)

    2011-04-01

    We review how second order equations for fields arise just by using projectors over Poincare invariant subspaces. We focus in the case of fields describing massive spin 1/2 particles, we propose a particular second order Lagrangian and present preliminary results in its quantization.

  5. Opportunistic beam training with hybrid analog/digital codebooks for mmWave systems

    KAUST Repository

    Eltayeb, Mohammed E.

    2016-02-25

    © 2015 IEEE. Millimeter wave (mmWave) communication is one solution to provide more spectrum than available at lower carrier frequencies. To provide sufficient link budget, mmWave systems will use beamforming with large antenna arrays at both the transmitter and receiver. Training these large arrays using conventional approaches taken at lower carrier frequencies, however, results in high overhead. In this paper, we propose a beam training algorithm that efficiently designs the beamforming vectors with low training overhead. Exploiting mmWave channel reciprocity, the proposed algorithm relaxes the need for an explicit feedback channel, and opportunistically terminates the training process when a desired quality of service is achieved. To construct the training beamforming vectors, a new multi-resolution codebook is developed for hybrid analog/digital architectures. Simulation results show that the proposed algorithm achieves a comparable rate to that obtained by exhaustive search solutions while requiring lower training overhead when compared to prior work.

  6. Deformation of second and third quantization

    Science.gov (United States)

    Faizal, Mir

    2015-03-01

    In this paper, we will deform the second and third quantized theories by deforming the canonical commutation relations in such a way that they become consistent with the generalized uncertainty principle. Thus, we will first deform the second quantized commutator and obtain a deformed version of the Wheeler-DeWitt equation. Then we will further deform the third quantized theory by deforming the third quantized canonical commutation relation. This way we will obtain a deformed version of the third quantized theory for the multiverse.

  7. Deformation of Second and Third Quantization

    CERN Document Server

    Faizal, Mir

    2015-01-01

    In this paper, we will deform the second and third quantized theories by deforming the canonical commutation relations in such a way that they become consistent with the generalized uncertainty principle. Thus, we will first deform the second quantized commutator and obtain a deformed version of the Wheeler-DeWitt equation. Then we will further deform the third quantized theory by deforming the third quantized canonical commutation relation. This way we will obtain a deformed version of the third quantized theory for the multiverse.

  8. Born-Jordan quantization theory and applications

    CERN Document Server

    de Gosson, Maurice A

    2016-01-01

    This book presents a comprehensive mathematical study of the operators behind the Born–Jordan quantization scheme. The Schrödinger and Heisenberg pictures of quantum mechanics are equivalent only if the Born–Jordan scheme is used. Thus, Born–Jordan quantization provides the only physically consistent quantization scheme, as opposed to the Weyl quantization commonly used by physicists. In this book we develop Born–Jordan quantization from an operator-theoretical point of view, and analyze in depth the conceptual differences between the two schemes. We discuss various physically motivated approaches, in particular the Feynman-integral point of view. One important and intriguing feature of Born-Jordan quantization is that it is not one-to-one: there are infinitely many classical observables whose quantization is zero.

  9. Quantized photonic spin Hall effect in graphene

    Science.gov (United States)

    Cai, Liang; Liu, Mengxia; Chen, Shizhen; Liu, Yachao; Shu, Weixing; Luo, Hailu; Wen, Shuangchun

    2017-01-01

    We examine the photonic spin Hall effect (SHE) in a graphene-substrate system with the presence of an external magnetic field. In the quantum Hall regime, we demonstrate that the in-plane and transverse spin-dependent splittings in the photonic SHE exhibit different quantized behaviors. The quantized SHE can be described as a consequence of a quantized geometric phase (Berry phase), which corresponds to the quantized spin-orbit interaction. Furthermore, an experimental scheme based on quantum weak value amplification is proposed to detect the quantized SHE in the terahertz frequency regime. By incorporating the quantum weak measurement techniques, the quantized photonic SHE holds great promise for detecting quantized Hall conductivity and the Berry phase. These results may bridge the gap between the electronic SHE and photonic SHE in graphene.

  10. Enhanced quantization particles, fields and gravity

    CERN Document Server

    Klauder, John R

    2015-01-01

    This pioneering book addresses the question: Are the standard procedures of canonical quantization fully satisfactory, or is there more to learn about assigning a proper quantum system to a given classical system? As shown in this book, the answer to this question is: The standard procedures of canonical quantization are not the whole story! This book offers alternative quantization procedures that complete the story of quantization. The initial chapters are designed to present the new procedures in a clear and simple manner for general readers. As is necessary, systems that exhibit acceptable results with conventional quantization lead to the same results when the new procedures are used for them. However, later chapters examine selected models that lead to unacceptable results when quantized conventionally. Fortunately, these same models lead to acceptable results when the new quantization procedures are used.

  11. Third Quantization and Quantum Cosmology.

    Science.gov (United States)

    McGuigan, Michael Deturck

    My thesis consists of three separate parts. Part one consists of a study of CP violation in the Kaon decay: K to pi pi gamma . To study the short distance contribution to the matrix element we developed an operator expansion for the effective Hamiltonian. An effective s to dgamma vertex arises through operator mixing. We evaluated several two-loop graphs in order to obtain the coefficient of this operator. We studied the long distance contributions to the matrix element and demonstrated that this was the dominant contribution. This explained why the polarization of the emitted photon is primarily of the magnetic type. Part two of my thesis involves the treatment of string theory at finite temperature. We introduced finite temperature into string theory by compactifying time on a twisted torus of radius beta = 1/kT, the reciprical of the temperature. The twisted torus takes into account the different thermal properties of bosons and fermions. We computed the one-loop vacuum amplitude Lambda(beta) on a twisted torus which is manifestly modular invariant. We found that lnZ(beta) = -betaVLambda (beta) where Z(beta) is the partition function and V the volume of the system. We computed the function sigma(E) which counts the number of multi-string states of total energy E by taking the inverse Laplace transform of Z( beta). We also studied the effect of finite temperature on the effective potentials which determine a string theory's compactification. The third part of my thesis involved the Wheeler DeWitt equation and a new interpretation of quantum cosmology. We examined a proposal by DeWitt for the normalization of solutions to the Wheeler-DeWitt equation. We avoided negative probability problems with this proposal by reinterpreting the Wheeler-DeWitt wave function as a second quantized field. As the arguments of the Wheeler-DeWitt wave functional are second quantized fields this represented a third quantization. We developed a mode decomposition for the third quantized

  12. Quantizing Constrained Systems New Perspectives

    CERN Document Server

    Kaplan, L; Heller, E J

    1997-01-01

    We consider quantum mechanics on constrained surfaces which have non-Euclidean metrics and variable Gaussian curvature. The old controversy about the ambiguities involving terms in the Hamiltonian of order hbar^2 multiplying the Gaussian curvature is addressed. We set out to clarify the matter by considering constraints to be the limits of large restoring forces as the constraint coordinates deviate from their constrained values. We find additional ambiguous terms of order hbar^2 involving freedom in the constraining potentials, demonstrating that the classical constrained Hamiltonian or Lagrangian cannot uniquely specify the quantization: the ambiguity of directly quantizing a constrained system is inherently unresolvable. However, there is never any problem with a physical quantum system, which cannot have infinite constraint forces and always fluctuates around the mean constraint values. The issue is addressed from the perspectives of adiabatic approximations in quantum mechanics, Feynman path integrals, a...

  13. Quantization via Linear homotopy types

    CERN Document Server

    Schreiber, Urs

    2014-01-01

    In the foundational logical framework of homotopy-type theory we discuss a natural formalization of secondary integral transforms in stable geometric homotopy theory. We observe that this yields a process of non-perturbative cohomological quantization of local pre-quantum field theory; and show that quantum anomaly cancellation amounts to realizing this as the boundary of a field theory that is given by genuine (primary) integral transforms, hence by linear polynomial functors. Recalling that traditional linear logic has semantics in symmetric monoidal categories and serves to formalize quantum mechanics, what we consider is its refinement to linear homotopy-type theory with semantics in stable infinity-categories of bundles of stable homotopy types (generalized cohomology theories) formalizing Lagrangian quantum field theory, following Nuiten and closely related to recent work by Haugseng and Hopkins-Lurie. For the reader interested in technical problems of quantization we provide non-perturbative quantizati...

  14. Third Quantization and Quantum Universes

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Sang Pyo, E-mail: sangkim@kunsan.ac.kr

    2014-01-15

    We study the third quantization of the Friedmann-Robertson-Walker cosmology with N-minimal massless fields. The third quantized Hamiltonian for the Wheeler-DeWitt equation in the minisuperspace consists of infinite number of intrinsic time-dependent, decoupled oscillators. The Hamiltonian has a pair of invariant operators for each universe with conserved momenta of the fields that play a role of the annihilation and the creation operators and that construct various quantum states for the universe. The closed universe exhibits an interesting feature of transitions from stable states to tachyonic states depending on the conserved momenta of the fields. In the classical forbidden unstable regime, the quantum states have googolplex growing position and conjugate momentum dispersions, which defy any measurements of the position of the universe.

  15. The Successive Mean Quantization Transform

    OpenAIRE

    Nilsson, Mikael; Dahl, Mattias; Claesson, Ingvar

    2005-01-01

    This paper presents the Successive Mean Quantization Transform (SMQT). The transform reveals the organization or structure of the data and removes properties such as gain and bias. The transform is described and applied in speech processing and image processing. The SMQT is considered as an extra processing step for the mel frequency cepstral coefficients commonly used in speech recognition. In image processing the transform is applied in automatic image enhancement and dynamic range compress...

  16. The Successive Mean Quantization Transform

    OpenAIRE

    Nilsson, Mikael; Dahl, Mattias; Claesson, Ingvar

    2005-01-01

    This paper presents the Successive Mean Quantization Transform (SMQT). The transform reveals the organization or structure of the data and removes properties such as gain and bias. The transform is described and applied in speech processing and image processing. The SMQT is considered as an extra processing step for the mel frequency cepstral coefficients commonly used in speech recognition. In image processing the transform is applied in automatic image enhancement and dynamic range compress...

  17. Landau level quantization and superconductivity

    Energy Technology Data Exchange (ETDEWEB)

    Akera, H. [Hokkaido Univ., Sapporo (Japan). Faculty of Engineering; MacDonald, A.H. [Indiana Univ., Bloomington, IN (United States). Dept. of Physics; Norman, M.R. [Argonne National Lab., IL (United States)

    1992-07-01

    A microscopic calculation of vortex-lattice states in two-dimensional electron systems at strong magnetic fields is made taking fully the Landau level quantization into account within the mean field scheme. Results of the order parameter and the local density of states are presented both in the limit of pairing in a single Landau level and in the semiclassical regime of weaker fields and differences from the Abrikosov vortex state are discussed.

  18. Hitchin's connection in metaplectic quantization

    DEFF Research Database (Denmark)

    Andersen, Jørgen Ellegaard; Gammelgaard, Niels Leth; Lauridsen, Magnus Roed

    2012-01-01

    We give a differential geometric construction of a connection, which we call the Hitchin connection, in the bundle of quantum Hilbert spaces arising from metaplectically corrected geometric quantization of a prequantizable, symplectic manifold, endowed with a rigid family of Kähler structures, all...... manifold in question. Furthermore, when we are in a setting similar to the moduli space, we give an explicit formula and show that this connection agrees with previous constructions....

  19. Quantization of Equations of Motion

    Directory of Open Access Journals (Sweden)

    D. Kochan

    2007-01-01

    Full Text Available The Classical Newton-Lagrange equations of motion represent the fundamental physical law of mechanics. Their traditional Lagrangian and/or Hamiltonian precursors when available are essential in the context of quantization. However, there are situations that lack Lagrangian and/or Hamiltonian settings. This paper discusses a description of classical dynamics and presents some irresponsible speculations about its quantization by introducing a certain canonical two-form ?. By its construction ? embodies kinetic energy and forces acting within the system (not their potential. A new type of variational principle employing differential two-form ? is introduced. Variation is performed over “umbilical surfaces“ instead of system histories. It provides correct Newton-Lagrange equations of motion. The quantization is inspired by the Feynman path integral approach. The quintessence is to rearrange it into an “umbilical world-sheet“ functional integral in accordance with the proposed variational principle. In the case of potential-generated forces, the new approach reduces to the standard quantum mechanics. As an example, Quantum Mechanics with friction is analyzed in detail. 

  20. Relativistic diffusion equation from stochastic quantization

    CERN Document Server

    Kazinski, P O

    2007-01-01

    The new scheme of stochastic quantization is proposed. This quantization procedure is equivalent to the deformation of an algebra of observables in the manner of deformation quantization with an imaginary deformation parameter (the Planck constant). We apply this method to the models of nonrelativistic and relativistic particles interacting with an electromagnetic field. In the first case we establish the equivalence of such a quantization to the Fokker-Planck equation with a special force. The application of the proposed quantization procedure to the model of a relativistic particle results in a relativistic generalization of the Fokker-Planck equation in the coordinate space, which in the absence of the electromagnetic field reduces to the relativistic diffusion (heat) equation. The stationary probability distribution functions for a stochastically quantized particle diffusing under a barrier and a particle in the potential of a harmonic oscillator are derived.

  1. Analysis of speech waveform quantization methods

    Directory of Open Access Journals (Sweden)

    Tadić Predrag R.

    2008-01-01

    Full Text Available Digitalization, consisting of sampling and quantization, is the first step in any digital signal processing algorithm. In most cases, the quantization is uniform. However, having knowledge of certain stochastic attributes of the signal (namely, the probability density function, or pdf, quantization can be made more efficient, in the sense of achieving a greater signal to quantization noise ratio. This means that narrower channel bandwidths are required for transmitting a signal of the same quality. Alternatively, if signal storage is of interest, rather than transmission, considerable savings in memory space can be made. This paper presents several available methods for speech signal pdf estimation, and quantizer optimization in the sense of minimizing the quantization error power.

  2. Message-Passing Estimation from Quantized Samples

    CERN Document Server

    Kamilov, Ulugbek; Rangan, Sundeep

    2011-01-01

    Estimation of a vector from quantized linear measurements is a common problem for which simple linear techniques are suboptimal -- sometimes greatly so. This paper develops generalized approximate message passing (GAMP) algorithms for minimum mean-squared error estimation of a random vector from quantized linear measurements, notably allowing the linear expansion to be overcomplete or undercomplete and the scalar quantization to be regular or non-regular. GAMP is a recently-developed class of algorithms that uses Gaussian approximations in belief propagation and allows arbitrary separable input and output channels. Scalar quantization of measurements is incorporated into the output channel formalism, leading to the first tractable and effective method for high-dimensional estimation problems involving non-regular scalar quantization. Non-regular quantization is empirically demonstrated to greatly improve rate--distortion performance in some problems with oversampling or with undersampling combined with a spar...

  3. M-theory and Deformation Quantization

    CERN Document Server

    Minic, D

    1999-01-01

    We discuss deformation quantization of the covariant, light-cone and conformal gauge-fixed p-brane actions (p>1) which are closely related to the structure of the classical and quantum Nambu brackets. It is known that deformation quantization of the Nambu bracket is not of the usual Moyal type. Yet the Nambu bracket can be quantized using the Zariski deformation quantization (discovered by Dito, Flato, Sternheimer and Takhtajan) which is based on factorization of polynomials in several real variables. We discuss a particular application of the Zariski deformed quantization in M-theory by considering the problem of a covariant formulation of Matrix theory. We propose that the problem of a covariant formulation of Matrix theory can be solved using the formalism of Zariski deformed quantization of the triple Nambu bracket.

  4. Space-Time Quantization and Nonlocal Field Theory -Relativistic Second Quantization of Matrix Model

    CERN Document Server

    Tanaka, S

    2000-01-01

    We propose relativistic second quantization of matrix model of D particles in a general framework of nonlocal field theory based on Snyder-Yang's quantized space-time. Second-quantized nonlocal field is in general noncommutative with quantized space-time, but conjectured to become commutative with light cone time $X^+$. This conjecture enables us to find second-quantized Hamiltonian of D particle system and Heisenberg's equation of motion of second-quantized {\\bf D} field in close contact with Hamiltonian given in matrix model. We propose Hamilton's principle of Lorentz-invariant action of {\\bf D} field and investigate what conditions or approximations are needed to reproduce the above Heisenberg's equation given in light cone time. Both noncommutativities appearing in position coordinates of D particles in matrix model and in quantized space-time will be eventually unified through second quantization of matrix model.

  5. Idealization Second Quantization of Composite Particles

    Institute of Scientific and Technical Information of China (English)

    ZHOU Duan-Lu; YU Si-Xia; SUN Chang-Pu

    2001-01-01

    A practical method is developed to deal with the second quantization of the many-body system containing the composite particles.In our treatment,the modes associated with composite particles are regarded approximately as independent ones compared with those of unbound particles.The field operators of the composite particles thus arise naturally in the second quantization Hamiltonian.To be emphasized,the second quantization Hamiltonian has the regular structures which correspond clearly to different physical processes.``

  6. Exact quantization conditions for cluster integrable systems

    Science.gov (United States)

    Franco, Sebastián; Hatsuda, Yasuyuki; Mariño, Marcos

    2016-06-01

    We propose exact quantization conditions for the quantum integrable systems of Goncharov and Kenyon, based on the enumerative geometry of the corresponding toric Calabi-Yau manifolds. Our conjecture builds upon recent results on the quantization of mirror curves, and generalizes a previous proposal for the quantization of the relativistic Toda lattice. We present explicit tests of our conjecture for the integrable systems associated to the resolved {{{C}}3}/{{{Z}}5} and {{{C}}3}/{{{Z}}6} orbifolds.

  7. Exact quantization conditions for cluster integrable systems

    CERN Document Server

    Franco, Sebastian; Marino, Marcos

    2015-01-01

    We propose exact quantization conditions for the quantum integrable systems of Goncharov and Kenyon, based on the enumerative geometry of the corresponding toric Calabi-Yau manifolds. Our conjecture builds upon recent results on the quantization of mirror curves, and generalizes a previous proposal for the quantization of the relativistic Toda lattice. We present explicit tests of our conjecture for the integrable systems associated to the resolved C^3/Z_5 and C^3/Z_6 orbifolds.

  8. At Low SNR Asymmetric Quantizers Are Better

    CERN Document Server

    Koch, Tobias

    2012-01-01

    We study the capacity of the discrete-time Gaussian channel when its output is quantized with a one-bit quantizer. We focus on the low signal-to-noise ratio (SNR) regime, where communication at very low spectral efficiencies takes place. In this regime a symmetric threshold quantizer is known to reduce channel capacity by 2/pi, i.e., to cause an asymptotic power loss of approximately two decibels. Here it is shown that this power loss can be entirely avoided by using asymmetric threshold quantizers and asymmetric signaling constellations. We prove that in order to avoid this power loss flash-signaling input-distributions are essential. Consequently, one-bit output quantization of the Gaussian channel reduces spectral efficiency. Threshold quantizers are not only asymptotically optimal: as we prove, at every fixed SNR, a threshold quantizer maximizes capacity among all one-bit output quantizers. The picture changes on the Rayleigh-fading channel. In the noncoherent case we show that a one-bit output quantizer ...

  9. Is Fundamental Particle Mass 4-pi Quantized?

    Directory of Open Access Journals (Sweden)

    Stone R. A. Jr.

    2010-01-01

    Full Text Available The Standard Model lacks an explanation for the specific mass values of the fundamental particles. This is to report that a single spin quantized mass formula can produce the masses of the proton, the $W$, and the three electron generations. The $4pi$ mass quantization pattern limits the electron generations to three, while the particle's generational property is one of the components of the proposed intra-particle quantization process. Although the developed relationships are presently phenomenological, so was Bohr's atomic quantization proposal that lead to quantum mechanics.

  10. LVQ-SMOTE - Learning Vector Quantization based Synthetic Minority Over-sampling Technique for biomedical data.

    Science.gov (United States)

    Nakamura, Munehiro; Kajiwara, Yusuke; Otsuka, Atsushi; Kimura, Haruhiko

    2013-10-02

    Over-sampling methods based on Synthetic Minority Over-sampling Technique (SMOTE) have been proposed for classification problems of imbalanced biomedical data. However, the existing over-sampling methods achieve slightly better or sometimes worse result than the simplest SMOTE. In order to improve the effectiveness of SMOTE, this paper presents a novel over-sampling method using codebooks obtained by the learning vector quantization. In general, even when an existing SMOTE applied to a biomedical dataset, its empty feature space is still so huge that most classification algorithms would not perform well on estimating borderlines between classes. To tackle this problem, our over-sampling method generates synthetic samples which occupy more feature space than the other SMOTE algorithms. Briefly saying, our over-sampling method enables to generate useful synthetic samples by referring to actual samples taken from real-world datasets. Experiments on eight real-world imbalanced datasets demonstrate that our proposed over-sampling method performs better than the simplest SMOTE on four of five standard classification algorithms. Moreover, it is seen that the performance of our method increases if the latest SMOTE called MWMOTE is used in our algorithm. Experiments on datasets for β-turn types prediction show some important patterns that have not been seen in previous analyses. The proposed over-sampling method generates useful synthetic samples for the classification of imbalanced biomedical data. Besides, the proposed over-sampling method is basically compatible with basic classification algorithms and the existing over-sampling methods.

  11. Efficient gray-level digital image watermarking based on vector quantization

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Digital watermarking has been presented as a new method for copyright protection by embedding a se cret signal in a digital image or video sequence. Common digital image watermarking techniques are based on the concept of spread-spectrum communications, which can be classified in two catalogues: spatial-domain and transform-domain based. Most of transform-domain watermarking methods are based on discrete cosine trans forms (DCT) and robust to JPEG lossy compression. Recently, digital image watermarking based on another important lossy compression technique, vector quantization (VQ), has been presented, which carries water mark information by codeword indices. It is secret and efficient, and is robust to VQ compression with the same codebook. However, the embedded information is less and the extraction process requires the original image.This paper presents a more efficient VQ-based image watermarking method, which can embed a large gray-level watermark into the original image with less extra distortion and perform the watermark extraction without the original image. In addition, the proposed watermarking algorithm is very secret because two keys are required for watermark extraction. Experimental results demonstrate the effectiveness of the proposed technique.

  12. Greedy Multiple Instance Learning via Codebook Learning and Nearest Neighbor Voting

    CERN Document Server

    Chen, Gang

    2012-01-01

    Multiple instance learning (MIL) has attracted great attention recently in machine learning community. However, most MIL algorithms are very slow and cannot be applied to large datasets. In this paper, we propose a greedy strategy to speed up the multiple instance learning process. Our contribution is two fold. First, we propose a density ratio model, and show that maximizing a density ratio function is the low bound of the DD model under certain conditions. Secondly, we make use of a histogram ratio between positive bags and negative bags to represent the density ratio function and find codebooks separately for positive bags and negative bags by a greedy strategy. For testing, we make use of a nearest neighbor strategy to classify new bags. We test our method on both small benchmark datasets and the large TRECVID MED11 dataset. The experimental results show that our method yields comparable accuracy to the current state of the art, while being up to at least one order of magnitude faster.

  13. Schwinger Mechanism with Stochastic Quantization

    CERN Document Server

    Fukushima, Kenji

    2014-01-01

    We prescribe a formulation of the particle production with real-time Stochastic Quantization. To construct the retarded and the time-ordered propagators we decompose the stochastic variables into positive- and negative-energy parts. In this way we demonstrate how to derive the Schwinger mechanism under a time-dependent electric field. We also discuss a physical interpretation with help of numerical simulations and develop an analogue to the one-dimensional scattering with the non-relativistic Schroedinger equation. We can then reformulate the Schwinger mechanism as the high-energy quantum reflection problem rather than tunneling.

  14. Quantizing the damped harmonic oscillator

    Energy Technology Data Exchange (ETDEWEB)

    Latimer, D C [Department of Physics and Astronomy, Vanderbilt University, Nashville, Tennessee 37235 (United States)

    2005-03-04

    We consider the Fermi quantization of the classical damped harmonic oscillator (dho). In past work on the subject, authors double the phase space of the dho in order to close the system at each moment in time. For an infinite-dimensional phase space, this method requires one to construct a representation of the CAR algebra for each time. We show that the unitary dilation of the contraction semigroup governing the dynamics of the system is a logical extension of the doubling procedure, and it allows one to avoid the mathematical difficulties encountered with the previous method.

  15. Deformation quantization of principal bundles

    CERN Document Server

    Aschieri, Paolo

    2016-01-01

    We outline how Drinfeld twist deformation techniques can be applied to the deformation quantization of principal bundles into noncommutative principal bundles, and more in general to the deformation of Hopf-Galois extensions. First we twist deform the structure group in a quantum group, and this leads to a deformation of the fibers of the principal bundle. Next we twist deform a subgroup of the group of authomorphisms of the principal bundle, and this leads to a noncommutative base space. Considering both deformations we obtain noncommutative principal bundles with noncommutative fiber and base space as well.

  16. Number-Phase Quantization Scheme for L-C Circuit

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    For a mesoscopic L-C circuit, besides the Louisell's quantization scheme in which electric charge q and electric current Ⅰ are respectively quantized as the coordinate operator Q and momentum operator P, in this paper we propose a new quantization scheme in the context of number-phase quantization through the standard Lagrangian formalism. The comparison between this number-phase quantization with the Josephson junction's Cooper pair numberphase-difference quantization scheme is made.

  17. Quantization of super Teichmueller spaces

    Energy Technology Data Exchange (ETDEWEB)

    Aghaei, Nezhla

    2016-08-15

    The quantization of the Teichmueller spaces of Riemann surfaces has found important applications to conformal field theory and N=2 supersymmetric gauge theories. We construct a quantization of the Teichmueller spaces of super Riemann surfaces, using coordinates associated to the ideal triangulations of super Riemann surfaces. A new feature is the non-trivial dependence on the choice of a spin structure which can be encoded combinatorially in a certain refinement of the ideal triangulation. We construct a projective unitary representation of the groupoid of changes of refined ideal triangulations. Therefore, we demonstrate that the dependence of the resulting quantum theory on the choice of a triangulation is inessential. In the quantum Teichmueller theory, it was observed that the key object defining the Teichmueller theory has a close relation to the representation theory of the Borel half of U{sub q}(sl(2)). In our research we observed that the role of U{sub q}(sl(2)) is taken by quantum superalgebra U{sub q}(osp(1 vertical stroke 2)). A Borel half of U{sub q}(osp(1 vertical stroke 2)) is the super quantum plane. The canonical element of the Heisenberg double of the quantum super plane is evaluated in certain infinite dimensional representations on L{sup 2}(R) x C{sup 1} {sup vertical} {sup stroke} {sup 1} and compared to the flip operator from the Teichmueller theory of super Riemann surfaces.

  18. Cosmology Quantized in Cosmic Time

    CERN Document Server

    Weinstein, M; Weinstein, Marvin; Akhoury, Ratindranath

    2004-01-01

    This paper discusses the problem of inflation in the context of Friedmann-Robertson-Walker Cosmology. We show how, after a simple change of variables, to quantize the problem in a way which parallels the classical discussion. The result is that two of the Einstein equations arise as exact equations of motion and one of the usual Einstein equations (suitably quantized) survives as a constraint equation to be imposed on the space of physical states. However, the Friedmann equation, which is also a constraint equation and which is the basis of the Wheeler-deWitt equation, acquires a welcome quantum correction that becomes significant for small scale factors. To clarify the general formalism and explicitly show why we choose to weaken the statement of the Wheeler-deWitt equation, we apply the general formalism to de Sitter space. After exactly solving the relevant Heisenberg equations of motion we give a detailed discussion of the subtleties associated with defining physical states and the emergence of the classi...

  19. Weak associativity and deformation quantization

    Directory of Open Access Journals (Sweden)

    V.G. Kupriyanov

    2016-09-01

    Full Text Available Non-commutativity and non-associativity are quite natural in string theory. For open strings it appears due to the presence of non-vanishing background two-form in the world volume of Dirichlet brane, while in closed string theory the flux compactifications with non-vanishing three-form also lead to non-geometric backgrounds. In this paper, working in the framework of deformation quantization, we study the violation of associativity imposing the condition that the associator of three elements should vanish whenever each two of them are equal. The corresponding star products are called alternative and satisfy important for physical applications properties like the Moufang identities, alternative identities, Artin's theorem, etc. The condition of alternativity is invariant under the gauge transformations, just like it happens in the associative case. The price to pay is the restriction on the non-associative algebra which can be represented by the alternative star product, it should satisfy the Malcev identity. The example of nontrivial Malcev algebra is the algebra of imaginary octonions. For this case we construct an explicit expression of the non-associative and alternative star product. We also discuss the quantization of Malcev–Poisson algebras of general form, study its properties and provide the lower order expression for the alternative star product. To conclude we define the integration on the algebra of the alternative star products and show that the integrated associator vanishes.

  20. Quantization of Presymplectic Manifolds and Circle Actions

    CERN Document Server

    Silva, A C; Tolman, S; Silva, Ana Canas da; Karshon, Yael; Tolman, Susan

    1997-01-01

    We prove several versions of "quantization commutes with reduction" for circle actions on manifolds that are not symplectic. Instead, these manifolds possess a weaker structure, such as a spin^c structure. Our theorems work whenever the quantization data and the reduction data are compatible; this condition always holds if we start from a presymplectic (in particular, symplectic) manifold.

  1. Quantization of Electromagnetic Fields in Cavities

    Science.gov (United States)

    Kakazu, Kiyotaka; Oshiro, Kazunori

    1996-01-01

    A quantization procedure for the electromagnetic field in a rectangular cavity with perfect conductor walls is presented, where a decomposition formula of the field plays an essential role. All vector mode functions are obtained by using the decomposition. After expanding the field in terms of the vector mode functions, we get the quantized electromagnetic Hamiltonian.

  2. Kähler Quantization and Hitchin Connections

    DEFF Research Database (Denmark)

    Leth Gammelgaard, Niels

    such deformation quantization, which uses Feynman graphs to encode the relevant differential operators. In particular, this yields an explicit formula for the Berezin-Toeplitz star product. For geometric quantization, we consider Andersen's generalization of Hitchin's projectively flat connection to a general...

  3. The logical quantization of algebraic groups

    Science.gov (United States)

    Nishimura, Hirokazu

    1995-05-01

    In a previous paper we introduced a highly abstract framework within which the theory of manuals initiated by Foulis and Randall is to be developed. The framework enabled us in a subsequent paper to quantize the notion of a set. Following these lines, this paper is devoted to quantizing algebraic groups viewed from Grothendieck's functorial standpoint.

  4. Bimodules and branes in deformation quantization

    CERN Document Server

    Calaque, Damien; Ferrario, Andrea; Rossi, Carlo A

    2009-01-01

    We prove a version of Kontsevich's formality theorem for two subspaces (branes) of a vector space $X$. The result implies in particular that the Kontsevich deformation quantizations of $\\mathrm{S}(X^*)$ and $\\wedge(X)$ associated with a quadratic Poisson structure are Koszul dual. This answers an open question in Shoikhet's recent paper on Koszul duality in deformation quantization.

  5. The First-Quantized Theory of Photons

    Institute of Scientific and Technical Information of China (English)

    WANG Zhi-Yong; XIONG Cai-Dong; Keller Ole

    2007-01-01

    In near-field optics and optical tunnelling theory, photon wave mechanics, I.e. The first-quantized theory of photons, allows us to address the spatial field localization problem in a flexible manner which links smoothly to classical electromagnetics. We develop photon wave mechanics in a rigorous and unified way, based on which field quantization is obtained in a new way.

  6. Affine Quantization and the Initial Cosmological Singularity

    CERN Document Server

    Fanuel, Michaël

    2012-01-01

    A toy model for quantum cosmology is suggested and quantized in the light of the Affine Coherent State Quantization procedure. The quantum corrections to the classical dynamics seem to provide a potential barrier term, as already suggested in other models studied in the literature. The possible application of this method to more realistic minisuperspace models is envisaged.

  7. Integral quantizations with two basic examples

    Energy Technology Data Exchange (ETDEWEB)

    Bergeron, H., E-mail: herve.bergeron@u-psud.fr [Univ Paris-Sud, ISMO, UMR 8214, 91405 Orsay (France); Gazeau, J.P., E-mail: gazeau@apc.univ-paris7.fr [Centro Brasileiro de Pesquisas Fisicas, Rua Xavier Sigaud 150, 22290-180 - Rio de Janeiro, RJ (Brazil); APC, UMR 7164, Univ Paris Diderot, Sorbonne Paris Cité, 75205 Paris (France)

    2014-05-15

    The paper concerns integral quantization, a procedure based on operator-valued measure and resolution of the identity. We insist on covariance properties in the important case where group representation theory is involved. We also insist on the inherent probabilistic aspects of this classical–quantum map. The approach includes and generalizes coherent state quantization. Two applications based on group representation are carried out. The first one concerns the Weyl–Heisenberg group and the euclidean plane viewed as the corresponding phase space. We show that a world of quantizations exist, which yield the canonical commutation rule and the usual quantum spectrum of the harmonic oscillator. The second one concerns the affine group of the real line and gives rise to an interesting regularization of the dilation origin in the half-plane viewed as the corresponding phase space. -- Highlights: •Original approach to quantization based on (positive) operator-valued measures. •Includes Berezin–Klauder–Toeplitz and Weyl–Wigner quantizations. •Infinitely many such quantizations produce canonical commutation rule. •Set of objects to be quantized is enlarged in order to include singular functions or distributions. •Are given illuminating examples like quantum angle and affine or wavelet quantization.

  8. Extended BRST quantization in general coordinates

    CERN Document Server

    Geyer, B; Nersessian, A B

    2002-01-01

    We propose an extended BRST invariant Lagrangian quantization scheme of general gauge theories based on explicit realization of "modified triplectic algebra" in general coordinates. All the known Lagrangian quantization schemes based on the extended BRST symmetry are obtained by specifying the (free) parameters of that method.

  9. Covariant Photon Quantization in the SME

    CERN Document Server

    Colladay, Don

    2013-01-01

    The Gupta Bleuler quantization procedure is applied to the SME photon sector. A direct application of the method to the massless case fails due to an unavoidable incompleteness in the polarization states. A mass term can be included into the photon lagrangian to rescue the quantization procedure and maintain covariance.

  10. Modulation and coding for quantized channels

    NARCIS (Netherlands)

    Shao, X.; Cronie, H.S.; Philips, W.

    2007-01-01

    We investigate reliable communication over quantized channels from an information theoretical point of view. People seldom consider the effect of quantization in conventional coded modulation systems since Analog-to-Digital (AD) converters used in these systems always have high resolution, e.g. 2/3

  11. Quantization Noise Shaping on Arbitrary Frame Expansions

    Directory of Open Access Journals (Sweden)

    Boufounos Petros T

    2006-01-01

    Full Text Available Quantization noise shaping is commonly used in oversampled A/D and D/A converters with uniform sampling. This paper considers quantization noise shaping for arbitrary finite frame expansions based on generalizing the view of first-order classical oversampled noise shaping as a compensation of the quantization error through projections. Two levels of generalization are developed, one a special case of the other, and two different cost models are proposed to evaluate the quantizer structures. Within our framework, the synthesis frame vectors are assumed given, and the computational complexity is in the initial determination of frame vector ordering, carried out off-line as part of the quantizer design. We consider the extension of the results to infinite shift-invariant frames and consider in particular filtering and oversampled filter banks.

  12. Correlation Statistics of Quantized Noiselike Signals

    CERN Document Server

    Gwinn, C

    2004-01-01

    I calculate the statistics of correlation of two digitized noiselike signals, which are drawn from complex Gaussian distributions, sampled, quantized, correlated, and averaged. Averaged over many such samples, the correlation r approaches a Gaussian distribution. The mean and variance of r fully characterize the distribution of r. The mean corresponds to the reproducible part of the measurement, and the variance corresponds to the random part, or noise. I investigate the case of nonnegligible covariance rho between the signals. Noise in the correlation can increase or decrease, depending on quantizer parameters, when rho increases. This contrasts with the correlation of continuously valued or unquantized signals, for which the noise in phase with rho increases with increasing rho, and noise out of phase decreases. Indeed, for some quantizer parameters, I find that the correlation of quantized signals provides a more accurate estimate of rho than would correlation without quantization. I present analytic resul...

  13. Codebook Design and Hybrid Digital/Analog Coding for Parallel Rayleigh Fading Channels

    OpenAIRE

    Shi, Shuying; Larsson, Erik G.; Skoglund, Mikael

    2011-01-01

    Low-delay source-channel transmission over parallel fading channels is studied. In this scenario separate sourceand channel coding is highly suboptimal. A scheme based on hybrid digital/analog joint source-channel coding istherefore proposed, employing scalar quantization and polynomial-based analog bandwidth expansion. Simulationsdemonstrate substantial performance gains. Funding agencies|European Community|248993|EL-LIIT||Knut and Alice Wallenberg Foundation||

  14. Codebook Selection Scheme for LTE-Advanced System%LTE-A系统中的码字选择方案

    Institute of Scientific and Technical Information of China (English)

    林雪红

    2014-01-01

    利用先进的长期演进系统中8天线预编码2级码本结构,提出了分步反馈长时预编码矩阵指示符和短时预编码矩阵指示符的码字选择算法.接收端根据信道容量近似解的最大值计算反馈长时预编码矩阵指示符,然后通过遍历方法确定短时预编码矩阵指示符的反馈值.该方法能提高反馈的有效性,降低计算复杂度.仿真结果表明,分步反馈预编码码字选择算法的性能比最优码字选择算法相差约0郾2 dB.%Based on an eight antenna double codebook in long term evolution advanced system, the code-book selection strategy is proposed by feedback long term precoding matrix index and short term precoding matrix index separately. The long term precoding matrix indexis calculated by approximating channel ca-pacity and the short term precoding matrix indexis searched by maximizing channel capacities. Simulation shows that the feedback overload and computational complexity are dramatically reduced performance deg-radation with only about 0.2 dB compared with the optimal codebook selection scheme.

  15. The Necessity of Quantizing Gravity

    CERN Document Server

    Adelman, Jeremy

    2015-01-01

    The Eppley Hannah thought experiment is often cited as justification for attempts by theorists to develop a complete, consistent theory of quantum gravity. A modification of the earlier "Heisenberg microscope" argument for the necessity of quantized light, the Eppley-Hannah thought experiment purports to show that purely classical gravitational waves would either not conserve energy or else allow for violations of the uncertainty principle. However, several subsequent papers have cast doubt as to the validity of the Eppley-Hannah argument. In this paper, we attempt to resurrect the Eppley-Hannah thought experiment by modifying the original argument in such a manner as to render it immune to the present criticisms levied against it.

  16. Breathers on Quantized Superfluid Vortices

    CERN Document Server

    Salman, Hayder

    2013-01-01

    We consider the propagation of breathers along a quantised superfluid vortex. Using the correspondence between the local induction approximation (LIA) and the nonlinear Schr\\"odinger equation, we identify a set of initial conditions corresponding to breather solutions of vortex motion governed by the LIA. These initial conditions, which give rise to a long-wavelength modulational instability, result in the emergence of large amplitude perturbations that are localised in both space and time. The emergent structures on the vortex filament are analogous to loop solitons. Although the breather solutions we study are exact solutions of the LIA equations, we demonstrate through full numerical simulations that their key emergent attributes carry over to vortex dynamics governed by the Biot-Savart law and to quantized vortices described by the Gross-Pitaevskii equation. The breather excitations can lead to self-reconnections, a mechanism that can play an important role within the cross-over range of scales in superfl...

  17. Twisted supergravity and its quantization

    CERN Document Server

    Costello, Kevin

    2016-01-01

    Twisted supergravity is supergravity in a background where the bosonic ghost field takes a non-zero value. This is the supergravity counterpart of the familiar concept of twisting supersymmetric field theories. In this paper, we give conjectural descriptions of type IIA and IIB supergravity in $10$ dimensions. Our conjectural descriptions are in terms of the closed-string field theories associated to certain topological string theories, and we conjecture that these topological string theories are twists of the physical string theories. For type IIB, the results of arXiv:1505.6703 show that our candidate twisted supergravity theory admits a unique quantization in perturbation theory. This is despite the fact that the theories, like the original physical theories, are non-renormalizable. Although we do not prove our conjectures, we amass considerable evidence. We find that our candidates for the twisted supergravity theories contain the residual supersymmetry one would expect. We also prove (using heavily a res...

  18. Cosmology Quantized in Cosmic Time

    Energy Technology Data Exchange (ETDEWEB)

    Weinstein, M

    2004-06-03

    This paper discusses the problem of inflation in the context of Friedmann-Robertson-Walker Cosmology. We show how, after a simple change of variables, to quantize the problem in a way which parallels the classical discussion. The result is that two of the Einstein equations arise as exact equations of motion and one of the usual Einstein equations (suitably quantized) survives as a constraint equation to be imposed on the space of physical states. However, the Friedmann equation, which is also a constraint equation and which is the basis of the Wheeler-deWitt equation, acquires a welcome quantum correction that becomes significant for small scale factors. We discuss the extension of this result to a full quantum mechanical derivation of the anisotropy ({delta} {rho}/{rho}) in the cosmic microwave background radiation, and the possibility that the extra term in the Friedmann equation could have observable consequences. To clarify the general formalism and explicitly show why we choose to weaken the statement of the Wheeler-deWitt equation, we apply the general formalism to de Sitter space. After exactly solving the relevant Heisenberg equations of motion we give a detailed discussion of the subtleties associated with defining physical states and the emergence of the classical theory. This computation provides the striking result that quantum corrections to this long wavelength limit of gravity eliminate the problem of the big crunch. We also show that the same corrections lead to possibly measurable effects on the CMB radiation. For the sake of completeness, we discuss the special case, {lambda} = 0, and its relation to Minkowski space. Finally, we suggest interesting ways in which these techniques can be generalized to cast light on the question of chaotic or eternal inflation. In particular, we suggest one can put an experimental lower bound on the distance to a universe with a scale factor very different from our own, by looking at its effects on our CMB

  19. The Quantization of Gravity Dynamic Approach

    CERN Document Server

    Vergeles, S N

    1996-01-01

    On the basis of dynamic quantization method we build in this paper a new mathematically correct quantization scheme of gravity. In the frame of this scheme we develop a canonical formalism in tetrad-connection variables in 4-D theory of pure gravity. In this formalism the regularized quantized fields corresponding to the classical tetrad and connection fields are constructed. It is shown, that the regularized fields satisfy to general covariant equations of motion, which have the classical form. In order to solve these equations the iterative procedure is offered.

  20. The symplectic camel and phase space quantization

    Energy Technology Data Exchange (ETDEWEB)

    Gosson, Maurice de [Blekinge Institute of Technology, Karlskrona (Sweden)

    2001-11-30

    We show that a result of symplectic topology, Gromov's non-squeezing theorem, also known as the 'principle of the symplectic camel', can be used to quantize phase space in cells. That quantization scheme leads to the correct energy levels for integrable systems and to Maslov quantization of Lagrangian manifolds by purely topological arguments. We finally show that the argument leading to the proof of the non-squeezing theorem leads to a classical form of Heisenberg's inequalities. (author)

  1. Is Fundamental Particle Mass 4π Quantized?

    Directory of Open Access Journals (Sweden)

    Stone R. A. Jr.

    2010-01-01

    Full Text Available The Standard Model lacks an explanation for the specific mass values of the fundamen- tal particles. This is to report that a single spin quantized mass formula can produce the masses of the proton, the W , and the three electron generations. The 4 mass quanti- zation pattern limits the electron generations to three, while the particle’s generational property is one of the components of the proposed intra-particle quantization process. Although the developed relationships are presently phenomenological, so was Bohr’s atomic quantization proposal that lead to quantum mechanics.

  2. Stochastic Variational Method as a Quantization Scheme II: Quantization of Electromagnetic Fields

    CERN Document Server

    Kodama, T Koide T

    2014-01-01

    Quantization of electromagnetic fields is investigated in the framework of stochastic variational method (SVM). Differently from the canonical quantization, this method does not require canonical form and quantization can be performed directly from the gauge invariant Lagrangian. The gauge condition is used to choose dynamically independent variables. We verify that, in the Coulomb gauge condition, SVM result is completely equivalent to the traditional result. On the other hand, in the Lorentz gauge condition, SVM quantization can be performed without introducing the indefinite metric. The temporal and longitudinal components of the gauge filed, then, behave as c-number functionals affected by quantum fluctuation through the interaction with charged matter fields. To see further the relation between SVM and the canonical quantization, we quantize the usual gauge Lagrangian with the Fermi term and argue a stochastic process with a negative second order correlation is introduced to reproduce the indefinite metr...

  3. Coordination of Passive Systems under Quantized Measurements

    NARCIS (Netherlands)

    De Persis, Claudio; Jayawardhana, Bayu

    2012-01-01

    In this paper we investigate a passivity approach to collective coordination and synchronization problems in the presence of quantized measurements and show that coordination tasks can be achieved in a practical sense for a large class of passive systems.

  4. Binary Biometric Representation through Pairwise Polar Quantization

    NARCIS (Netherlands)

    Chen, Chun; Veldhuis, Raymond; Tistarelli, M.; Nixon, M.

    2009-01-01

    Binary biometric representations have great significance for data compression and template protection. In this paper, we introduce pairwise polar quantization. Furthermore, aiming to optimize the discrimination between the genuine Hamming distance (GHD) and the imposter Hamming distance (IHD), we pr

  5. Superfield extended BRST quantization in general coordinates

    CERN Document Server

    Geyer, B; Lavrov, P M; Moshin, P Y

    2004-01-01

    We propose a superfield formalism of Lagrangian BRST-antiBRST quantization of arbitrary gauge theories in general coordinates with the base manifold of fields and antifields desribed in terms of both bosonic and fermionic variables.

  6. Quantization of noncommutative completely integrable Hamiltonian systems

    CERN Document Server

    Giachetta, G; Sardanashvily, G

    2007-01-01

    Integrals of motion of a Hamiltonian system need not be commutative. The classical Mishchenko-Fomenko theorem enables one to quantize a noncommutative completely integrable Hamiltonian system around its invariant submanifold as an abelian completely integrable Hamiltonian system.

  7. Quantization of noncommutative completely integrable Hamiltonian systems

    Energy Technology Data Exchange (ETDEWEB)

    Giachetta, G. [Department of Mathematics and Informatics, University of Camerino, 62032 Camerino (Italy); Mangiarotti, L. [Department of Mathematics and Informatics, University of Camerino, 62032 Camerino (Italy); Sardanashvily, G. [Department of Theoretical Physics, Moscow State University, 117234 Moscow (Russian Federation)]. E-mail: gennadi.sardanashvily@unicam.it

    2007-02-26

    Integrals of motion of a Hamiltonian system need not commute. The classical Mishchenko-Fomenko theorem enables one to quantize a noncommutative completely integrable Hamiltonian system around its invariant submanifold as the Abelian one.

  8. Quantization of massive Weyl fields in vacuum

    CERN Document Server

    Dvornikov, Maxim

    2013-01-01

    We briefly review the main methods for the description of massive Weyl fields in vacuum. On the classical level we discuss Weyl fields expressed through Grassmann variables as well as having spinors with commuting components. In both approaches we quantize the system. We get the correct anticommutation relations between creation and annihilation operators, which result in the proper form of the total energy of the field. However, the commuting classical Weyl fields require the new method of quantization.

  9. On Quantizing Nilpotent and Solvable Basic Algebras

    OpenAIRE

    1999-01-01

    We prove an algebraic ``no-go theorem'' to the effect that a nontrivial Poisson algebra cannot be realized as an associative algebra with the commutator bracket. Using this, we show that there is an obstruction to quantizing the Poisson algebra of polynomials generated by a nilpotent basic algebra on a symplectic manifold. Finally, we explicitly construct a polynomial quantization of a symplectic manifold with a solvable basic algebra, thereby showing that the obstruction in the nilpotent cas...

  10. Third Quantization of Brans-Dicke Cosmology

    CERN Document Server

    Pimentel, L O; Pimentel, Luis O.; Mora, Cesar

    2001-01-01

    We study the third quantization of a Brans-Dicke toy model, we calculate the number density of the universes created from nothing and found that it has a Planckian form. Also, we calculated the uncertainty relation for this model by means of functional Schr"odinger equation and we found that fluctuations of the third-quantized universe field tends to a finite limit in the course of cosmic expansion.

  11. Quantized Matrix Algebras and Quantum Seeds

    DEFF Research Database (Denmark)

    Jakobsen, Hans Plesner; Pagani, Chiara

    2015-01-01

    We determine explicitly quantum seeds for classes of quantized matrix algebras. Furthermore, we obtain results on centres and block diagonal forms of these algebras. In the case where is an arbitrary root of unity, this further determines the degrees.......We determine explicitly quantum seeds for classes of quantized matrix algebras. Furthermore, we obtain results on centres and block diagonal forms of these algebras. In the case where is an arbitrary root of unity, this further determines the degrees....

  12. Canonical group quantization and boundary conditions

    Energy Technology Data Exchange (ETDEWEB)

    Jung, Florian

    2012-07-16

    In the present thesis, we study quantization of classical systems with non-trivial phase spaces using the group-theoretical quantization technique proposed by Isham. Our main goal is a better understanding of global and topological aspects of quantum theory. In practice, the group-theoretical approach enables direct quantization of systems subject to constraints and boundary conditions in a natural and physically transparent manner -- cases for which the canonical quantization method of Dirac fails. First, we provide a clarification of the quantization formalism. In contrast to prior treatments, we introduce a sharp distinction between the two group structures that are involved and explain their physical meaning. The benefit is a consistent and conceptually much clearer construction of the Canonical Group. In particular, we shed light upon the 'pathological' case for which the Canonical Group must be defined via a central Lie algebra extension and emphasise the role of the central extension in general. In addition, we study direct quantization of a particle restricted to a half-line with 'hard wall' boundary condition. Despite the apparent simplicity of this example, we show that a naive quantization attempt based on the cotangent bundle over the half-line as classical phase space leads to an incomplete quantum theory; the reflection which is a characteristic aspect of the 'hard wall' is not reproduced. Instead, we propose a different phase space that realises the necessary boundary condition as a topological feature and demonstrate that quantization yields a suitable quantum theory for the half-line model. The insights gained in the present special case improve our understanding of the relation between classical and quantum theory and illustrate how contact interactions may be incorporated.

  13. Perceptual vector quantization for video coding

    Science.gov (United States)

    Valin, Jean-Marc; Terriberry, Timothy B.

    2015-03-01

    This paper applies energy conservation principles to the Daala video codec using gain-shape vector quantization to encode a vector of AC coefficients as a length (gain) and direction (shape). The technique originates from the CELT mode of the Opus audio codec, where it is used to conserve the spectral envelope of an audio signal. Conserving energy in video has the potential to preserve textures rather than low-passing them. Explicitly quantizing a gain allows a simple contrast masking model with no signaling cost. Vector quantizing the shape keeps the number of degrees of freedom the same as scalar quantization, avoiding redundancy in the representation. We demonstrate how to predict the vector by transforming the space it is encoded in, rather than subtracting off the predictor, which would make energy conservation impossible. We also derive an encoding of the vector-quantized codewords that takes advantage of their non-uniform distribution. We show that the resulting technique outperforms scalar quantization by an average of 0.90 dB on still images, equivalent to a 24.8% reduction in bitrate at equal quality, while for videos, the improvement averages 0.83 dB, equivalent to a 13.7% reduction in bitrate.

  14. Controlling charge quantization with quantum fluctuations

    Science.gov (United States)

    Jezouin, S.; Iftikhar, Z.; Anthore, A.; Parmentier, F. D.; Gennser, U.; Cavanna, A.; Ouerghi, A.; Levkivskyi, I. P.; Idrisov, E.; Sukhorukov, E. V.; Glazman, L. I.; Pierre, F.

    2016-08-01

    In 1909, Millikan showed that the charge of electrically isolated systems is quantized in units of the elementary electron charge e. Today, the persistence of charge quantization in small, weakly connected conductors allows for circuits in which single electrons are manipulated, with applications in, for example, metrology, detectors and thermometry. However, as the connection strength is increased, the discreteness of charge is progressively reduced by quantum fluctuations. Here we report the full quantum control and characterization of charge quantization. By using semiconductor-based tunable elemental conduction channels to connect a micrometre-scale metallic island to a circuit, we explore the complete evolution of charge quantization while scanning the entire range of connection strengths, from a very weak (tunnel) to a perfect (ballistic) contact. We observe, when approaching the ballistic limit, that charge quantization is destroyed by quantum fluctuations, and scales as the square root of the residual probability for an electron to be reflected across the quantum channel; this scaling also applies beyond the different regimes of connection strength currently accessible to theory. At increased temperatures, the thermal fluctuations result in an exponential suppression of charge quantization and in a universal square-root scaling, valid for all connection strengths, in agreement with expectations. Besides being pertinent for the improvement of single-electron circuits and their applications, and for the metal-semiconductor hybrids relevant to topological quantum computing, knowledge of the quantum laws of electricity will be essential for the quantum engineering of future nanoelectronic devices.

  15. Codebook and explanatory note on the WageIndicator dataset: a worldwide, continuous, multilingual web-survey on work and wages with paper supplements

    NARCIS (Netherlands)

    Tijdens, K.; van Zijl, S.; Hughie-Williams, M.; van Klaveren, M.; Steinmetz, S.

    2010-01-01

    This paper details the WageIndicator web-survey, the questionnaire and its dataset. The paper is an update of previous codebooks and explanatory notes.1 In the past years, the WageIndicator web-survey and its datacollection has undergone several technological innovations. In 2009, it was decided to

  16. Weak associativity and deformation quantization

    CERN Document Server

    Kupriyanov, V G

    2016-01-01

    Non-commutativity is quite natural in string theory. For open strings it appears due to the presence of non-vanishing background two-form in the world volume of Dirichlet brane, while in closed string theory the flux compactifications with non-vanishing three-form also lead to non-commutativity. Except for some specific cases, like the constant $B$-field in open strings, the string coordinates are not only non-commutative, but also non-associative. It manifests the non-geometric nature of the consistent string vacua. The aim of this paper is to study the mathematical tools necessary to deal with non-associativity in physics. Working in the framework of deformation quantization we admit non-associative star products, but keep the violation of associativity under control. We require that the star associator of three functions should vanish whenever each two of them are iqual. Such a star product is called alternative. This condition imposes the restriction on non-associative algebras, the star commutator should...

  17. Quantizing N=2 Multicenter Solutions

    CERN Document Server

    de Boer, Jan; Messamah, Ilies; Bleeken, Dieter Van den

    2009-01-01

    N=2 supergravity in four dimensions, or equivalently N=1 supergravity in five dimensions, has an interesting set of BPS solutions that each correspond to a number of charged centers. This set contains black holes, black rings and their bound states, as well as many smooth solutions. Moduli spaces of such solutions carry a natural symplectic form which we determine, and which allows us to study their quantization. By counting the resulting wavefunctions we come to an independent derivation of some of the wall-crossing formulae. Knowledge of the explicit form of these wavefunctions allows us to find quantum resolutions to some apparent classical paradoxes such as solutions with barely bound centers and those with an infinitely deep throat. We show that quantum effects seem to cap off the throat at a finite depth and we give an estimate for the corresponding mass gap in the dual CFT. This is an interesting example of a system where quantum effects cannot be neglected at macroscopic scales even though the curvatu...

  18. Neural network vector quantization improves the diagnostic quality of computer-aided diagnosis in dynamic breast MRI

    Science.gov (United States)

    Wismüller, Axel; Meyer-Baese, Anke; Leinsinger, Gerda L.; Lange, Oliver; Schlossbauer, Thomas; Reiser, Maximilian F.

    2007-03-01

    We quantitatively evaluate a novel neural network pattern recognition approach for characterization of diagnostically challenging breast lesions in contrast-enhanced dynamic breast MRI. Eighty-two women with 84 indeterminate mammographic lesions (BIRADS III-IV, 38/46 benign/malignant lesions confirmed by histopathology and follow-up, median lesion diameter 12mm) were examined by dynamic contrast-enhanced breast MRI. The temporal signal dynamics results in an intensity time-series for each voxel represented by a 6-dimensional feature vector. These vectors were clustered by minimal-free-energy Vector Quantization (VQ), which identifies groups of pixels with similar enhancement kinetics as prototypical time-series, so-called codebook vectors. For comparison, conventional analysis based on lesion-specific averaged signal-intensity time-courses was performed according to a standardized semi-quantitative evaluation score. For quantitative assessment of diagnostic accuracy, areas under ROC curves (AUC) were computed for both VQ and standard classification methods. VQ increased the diagnostic accuracy for classification between benign and malignant lesions, as confirmed by quantitative ROC analysis: VQ results (AUC=0.760) clearly outperformed the conventional evaluation of lesion-specific averaged time-series (AUC=0.693). Thus, the diagnostic benefit of neural network VQ for MR mammography analysis is quantitatively documented by ROC evaluation in a large data base of diagnostically challenging small focal breast lesions. VQ outperforms the conventional method w.r.t. diagnostic accuracy.

  19. Tribology of the lubricant quantized sliding state.

    Science.gov (United States)

    Castelli, Ivano Eligio; Capozza, Rosario; Vanossi, Andrea; Santoro, Giuseppe E; Manini, Nicola; Tosatti, Erio

    2009-11-07

    In the framework of Langevin dynamics, we demonstrate clear evidence of the peculiar quantized sliding state, previously found in a simple one-dimensional boundary lubricated model [A. Vanossi et al., Phys. Rev. Lett. 97, 056101 (2006)], for a substantially less idealized two-dimensional description of a confined multilayer solid lubricant under shear. This dynamical state, marked by a nontrivial "quantized" ratio of the averaged lubricant center-of-mass velocity to the externally imposed sliding speed, is recovered, and shown to be robust against the effects of thermal fluctuations, quenched disorder in the confining substrates, and over a wide range of loading forces. The lubricant softness, setting the width of the propagating solitonic structures, is found to play a major role in promoting in-registry commensurate regions beneficial to this quantized sliding. By evaluating the force instantaneously exerted on the top plate, we find that this quantized sliding represents a dynamical "pinned" state, characterized by significantly low values of the kinetic friction. While the quantized sliding occurs due to solitons being driven gently, the transition to ordinary unpinned sliding regimes can involve lubricant melting due to large shear-induced Joule heating, for example at large speed.

  20. Relating field theories via stochastic quantization

    Science.gov (United States)

    Dijkgraaf, Robbert; Orlando, Domenico; Reffert, Susanne

    2010-01-01

    This note aims to subsume several apparently unrelated models under a common framework. Several examples of well-known quantum field theories are listed which are connected via stochastic quantization. We highlight the fact that the quantization method used to obtain the quantum crystal is a discrete analog of stochastic quantization. This model is of interest for string theory, since the (classical) melting crystal corner is related to the topological A-model. We outline several ideas for interpreting the quantum crystal on the string theory side of the correspondence, exploring interpretations in the Wheeler-De Witt framework and in terms of a non-Lorentz invariant limit of topological M-theory.

  1. Relating field theories via stochastic quantization

    Energy Technology Data Exchange (ETDEWEB)

    Dijkgraaf, Robbert [KdV Institute for Mathematics, University of Amsterdam, Plantage Muidergracht 24, 1018 TV Amsterdam (Netherlands); Institute for Theoretical Physics, University of Amsterdam, Valckenierstraat 65, 1018 XE Amsterdam (Netherlands); Orlando, Domenico [Institute for the Mathematics and Physics of the Universe, University of Tokyo, Kashiwa-no-Ha 5-1-5, Kashiwa-shi, 277-8568 Chiba (Japan); Reffert, Susanne, E-mail: susanne.reffert@impu.j [Institute for the Mathematics and Physics of the Universe, University of Tokyo, Kashiwa-no-Ha 5-1-5, Kashiwa-shi, 277-8568 Chiba (Japan)

    2010-01-11

    This note aims to subsume several apparently unrelated models under a common framework. Several examples of well-known quantum field theories are listed which are connected via stochastic quantization. We highlight the fact that the quantization method used to obtain the quantum crystal is a discrete analog of stochastic quantization. This model is of interest for string theory, since the (classical) melting crystal corner is related to the topological A-model. We outline several ideas for interpreting the quantum crystal on the string theory side of the correspondence, exploring interpretations in the Wheeler-De Witt framework and in terms of a non-Lorentz invariant limit of topological M-theory.

  2. Relating Field Theories via Stochastic Quantization

    CERN Document Server

    Dijkgraaf, Robbert; Reffert, Susanne

    2009-01-01

    This note aims to subsume several apparently unrelated models under a common framework. Several examples of well-known quantum field theories are listed which are connected via stochastic quantization. We highlight the fact that the quantization method used to obtain the quantum crystal is a discrete analog of stochastic quantization. This model is of interest for string theory, since the (classical) melting crystal corner is related to the topological A-model. We outline several ideas for interpreting the quantum crystal on the string theory side of the correspondence, exploring interpretations in the Wheeler-De Witt framework and in terms of a non-Lorentz invariant limit of topological M-theory.

  3. Quantization on Space-Time Hyperboloids

    CERN Document Server

    Biernat, Elmar P

    2011-01-01

    We quantize a relativistic massive complex spin-0 field and a relativistic massive spin-1/2 field on a space-time hyperboloid. We call this procedure point-form canonical quantization. Lorentz invariance of the hyperboloid implies that the 4 generators for translations become dynamic and interaction dependent, whereas the 6 generators for Lorentz transformations remain kinematic and interaction free. We expand the fields in terms of usual plane waves and prove the equivalence to equal-time quantization by representing the Poincare generators in a momentum basis. We formulate a generalized scattering theory for interacting fields by considering evolution of the system generated by the interaction dependent four-momentum operator. Finally we expand our generalized scattering operator in powers of the interaction and show its equivalence to the Dyson expansion of usual time-ordered perturbation theory.

  4. The Deuteron as a Canonically Quantized Biskyrmion

    CERN Document Server

    Acus, A; Norvaisas, E; Riska, D O

    2003-01-01

    The ground state configurations of the solution to Skyrme's topological soliton model for systems with baryon number larger than 1 are well approximated with rational map ans"atze, without individual baryon coordinates. Here canonical quantization of the baryon number 2 system, which represents the deuteron, is carried out in the rational map approximation. The solution, which is described by the 6 parameters of the chiral group SU(2)$times$SU(2), is stabilized by the quantum corrections. The matter density of the variational quantized solution has the required exponential large distance falloff and the quantum numbers of the deuteron. Similarly to the axially symmetric semiclassical solution, the radius and the quadrupole moment are, however, only about half as large as the corresponding empirical values. The quantized deuteron solution is constructed for representations of arbitrary dimension of the chiral group.

  5. Gravitational surface Hamiltonian and entropy quantization

    Directory of Open Access Journals (Sweden)

    Ashish Bakshi

    2017-02-01

    Full Text Available The surface Hamiltonian corresponding to the surface part of a gravitational action has xp structure where p is conjugate momentum of x. Moreover, it leads to TS on the horizon of a black hole. Here T and S are temperature and entropy of the horizon. Imposing the hermiticity condition we quantize this Hamiltonian. This leads to an equidistant spectrum of its eigenvalues. Using this we show that the entropy of the horizon is quantized. This analysis holds for any order of Lanczos–Lovelock gravity. For general relativity, the area spectrum is consistent with Bekenstein's observation. This provides a more robust confirmation of this earlier result as the calculation is based on the direct quantization of the Hamiltonian in the sense of usual quantum mechanics.

  6. Ambiguities in Quantizing a Classical System

    CERN Document Server

    Redmount, I H; Young, K; Redmount, Ian; Suen, Wai-Mo; Young, Kenneth

    1999-01-01

    One classical theory, as determined by an equation of motion or set of classical trajectories, can correspond to many unitarily {\\em in}equivalent quantum theories upon canonical quantization. This arises from a remarkable ambiguity, not previously investigated, in the construction of the classical (and hence the quantized) Hamiltonian or Lagrangian. This ambiguity is illustrated for systems with one degree of freedom: An arbitrary function of the constants of motion can be introduced into this construction. For example, the nonrelativistic and relativistic free particles follow identical classical trajectories, but the Hamiltonians or Lagrangians, and the canonically quantized versions of these descriptions, are inequivalent. Inequivalent descriptions of other systems, such as the harmonic oscillator, are also readily obtained.

  7. Gravitational surface Hamiltonian and entropy quantization

    Science.gov (United States)

    Bakshi, Ashish; Majhi, Bibhas Ranjan; Samanta, Saurav

    2017-02-01

    The surface Hamiltonian corresponding to the surface part of a gravitational action has xp structure where p is conjugate momentum of x. Moreover, it leads to TS on the horizon of a black hole. Here T and S are temperature and entropy of the horizon. Imposing the hermiticity condition we quantize this Hamiltonian. This leads to an equidistant spectrum of its eigenvalues. Using this we show that the entropy of the horizon is quantized. This analysis holds for any order of Lanczos-Lovelock gravity. For general relativity, the area spectrum is consistent with Bekenstein's observation. This provides a more robust confirmation of this earlier result as the calculation is based on the direct quantization of the Hamiltonian in the sense of usual quantum mechanics.

  8. Integration measure and extended BRST covariant quantization

    CERN Document Server

    Geyer, B; Nersessian, A P; Geyer, Bodo; Lavrov, Petr; Nersessian, Armen

    2001-01-01

    We propose an extended BRST invariant Lagrangian quantization scheme of general gauge theories based on an explicit realization of the modified triplectic algebra that was announced in our previous investigation (hep-th/0104189). The algebra includes, besides the odd operators $V^a$ appearing in the triplectic formalism, also the odd operators $U^a$ introduced within modified triplectic quantization, both of which being anti-Hamiltonian vector fields. We show that some even supersymplectic structure defined on the space of fields and antifields provides the extended BRST path integral with a well-defined integration measure. All the known Lagrangian quantization schemes based on the extended BRST symmetry are obtained by specifying the (free) parameters of that method.

  9. Multiple Parameter Estimation With Quantized Channel Output

    CERN Document Server

    Mezghani, Amine; Nossek, Josef A

    2010-01-01

    We present a general problem formulation for optimal parameter estimation based on quantized observations, with application to antenna array communication and processing (channel estimation, time-of-arrival (TOA) and direction-of-arrival (DOA) estimation). The work is of interest in the case when low resolution A/D-converters (ADCs) have to be used to enable higher sampling rate and to simplify the hardware. An Expectation-Maximization (EM) based algorithm is proposed for solving this problem in a general setting. Besides, we derive the Cramer-Rao Bound (CRB) and discuss the effects of quantization and the optimal choice of the ADC characteristic. Numerical and analytical analysis reveals that reliable estimation may still be possible even when the quantization is very coarse.

  10. Asymmetric Quantizers Are Better at Low SNR

    OpenAIRE

    2011-01-01

    We study the behavior of channel capacity when a one-bit quantizer is employed at the output of the discrete-time average-power-limited Gaussian channel. We focus on the low signal-to-noise ratio regime, where communication at very low spectral efficiencies takes place, as in Spread-Spectrum and Ultra-Wideband communications. It is well know that, in this regime, a symmetric one-bit quantizer reduces capacity by 2/pi, which translates to a power loss of approximately two decibels. Here we sho...

  11. Constraints on operator ordering from third quantization

    Science.gov (United States)

    Ohkuwa, Yoshiaki; Faizal, Mir; Ezawa, Yasuo

    2016-02-01

    In this paper, we analyse the Wheeler-DeWitt equation in the third quantized formalism. We will demonstrate that for certain operator ordering, the early stages of the universe are dominated by quantum fluctuations, and the universe becomes classical at later stages during the cosmic expansion. This is physically expected, if the universe is formed from quantum fluctuations in the third quantized formalism. So, we will argue that this physical requirement can be used to constrain the form of the operator ordering chosen. We will explicitly demonstrate this to be the case for two different cosmological models.

  12. Constraints on operator ordering from third quantization

    Energy Technology Data Exchange (ETDEWEB)

    Ohkuwa, Yoshiaki [Division of Mathematical Science, Department of Social Medicine, Faculty of Medicine, University of Miyazaki, Kihara 5200, Kiyotake-cho, Miyazaki, 889-1692 (Japan); Faizal, Mir, E-mail: f2mir@uwaterloo.ca [Department of Physics and Astronomy, University of Waterloo, Waterloo, Ontario N2L 3G1 (Canada); Ezawa, Yasuo [Department of Physics, Ehime University, 2-5 Bunkyo-cho, Matsuyama, 790-8577 (Japan)

    2016-02-15

    In this paper, we analyse the Wheeler–DeWitt equation in the third quantized formalism. We will demonstrate that for certain operator ordering, the early stages of the universe are dominated by quantum fluctuations, and the universe becomes classical at later stages during the cosmic expansion. This is physically expected, if the universe is formed from quantum fluctuations in the third quantized formalism. So, we will argue that this physical requirement can be used to constrain the form of the operator ordering chosen. We will explicitly demonstrate this to be the case for two different cosmological models.

  13. Minimal representations, geometric quantization, and unitarity.

    Science.gov (United States)

    Brylinski, R; Kostant, B

    1994-06-21

    In the framework of geometric quantization we explicitly construct, in a uniform fashion, a unitary minimal representation pio of every simply-connected real Lie group Go such that the maximal compact subgroup of Go has finite center and Go admits some minimal representation. We obtain algebraic and analytic results about pio. We give several results on the algebraic and symplectic geometry of the minimal nilpotent orbits and then "quantize" these results to obtain the corresponding representations. We assume (Lie Go)C is simple.

  14. Lorentz gauge quantization in synchronous coordinates

    CERN Document Server

    Garner, Christopher

    2016-01-01

    It has been shown that the Gupta-Bleuler method of quantization can be used to impose the Lorentz gauge condition in static space-times but not in cosmological space-times. This implies that the Gupta-Bleuler approach fails in general in non-static space-times. More recently, however, the Dirac method of quantizing constrained dynamical systems has been successfully employed to impose the Lorentz gauge in conformally flat space-times. In this paper we generalize this result by using Dirac's method to impose the Lorentz gauge in a general space-time region where the metric is expressed in synchronous coordinates.

  15. Quantization of wavelet packet audio coding

    Institute of Scientific and Technical Information of China (English)

    Tan Jianguo; Zhang Wenjun; Liu Peilin

    2006-01-01

    The method of quantization noise control of audio coding in the wavelet domain is proposed. Using the inverse Discrete Fourier Transform (DFT), it converts the masking threshold coming from MPEG psycho-acoustic model in the frequency domain to the signal in the time domain; the Discrete Wavelet Packet Transform (DWPT) is performed; the energy in each subband is regarded as the maximum allowed quantization noise energy. The experimental result shows that the proposed method can attain the nearly transparent audio quality below 64kbps for the most testing audio signals.

  16. Noncommutative Space-time from Quantized Twistors

    CERN Document Server

    Lukierski, Jerzy

    2013-01-01

    We consider the relativistic phase space coordinates (x_{\\mu},p_{\\mu}) as composite, described by functions of the primary pair of twistor coordinates. It appears that if twistor coordinates are canonicaly quantized the composite space-time coordinates are becoming noncommutative. We obtain deformed Heisenberg algebra which in order to be closed should be enlarged by the Pauli-Lubanski four-vector components. We further comment on star-product quantization of derived algebraic structures which permit to introduce spin-extended deformed Heisenberg algebra.

  17. Quantization Skipping Method for H.264/AVC Video Coding

    Institute of Scientific and Technical Information of China (English)

    Won-seon SONG; Min-cheol HONG

    2010-01-01

    This paper presents a quantization skipping method for H.264/AVC video coding standard. In order to reduce the computational-cost of quantization process coming from integer discrete cosine transform of H.264/AVC, a quantization skipping condition is derived by the analysis of integer transform and quantization procedures. The experimental results show that the proposed algorithm has the capability to reduce the computational cost about 10%~25%.

  18. Performance of Quantization Factor in H.261 Video Coding

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The quantizaion factor through buffer pure occupy algorithm isprovided. Through the simulation, firstly the relationship between quantization factor and compression ratio is analyzed, secondly the PSNR of the image with the quantization factor is discussed, and finally the control to the output rate of the coder by adjusting the value of quantization factor is studied.

  19. Variable Dimension Trellis-Coded Quantization of Sinusoidal Parameters

    DEFF Research Database (Denmark)

    Larsen, Morten Holm; Christensen, Mads G.; Jensen, Søren Holdt

    2008-01-01

    In this letter, we propose joint quantization of the parameters of a set of sinusoids based on the theory of trellis-coded quantization. A particular advantage of this approach is that it allows for joint quantization of a variable number of sinusoids, which is particularly relevant in variable...

  20. A Feynman-Kac formula for geometric quantization

    Institute of Scientific and Technical Information of China (English)

    郭懋正; 钱敏; 王正栋

    1996-01-01

    The geometric quantization on a homogeneous manifold is studied. For any quantizable function f, the stochastical expression for the unitary group exp(itQ (f)) generated by the quantized operator Q(f) is established. As an application, a Feynman-Kac formula for the compact semisimple Lie group is rederived.

  1. Visual data mining for quantized spatial data

    Science.gov (United States)

    Braverman, Amy; Kahn, Brian

    2004-01-01

    In previous papers we've shown how a well known data compression algorithm called Entropy-constrained Vector Quantization ( can be modified to reduce the size and complexity of very large, satellite data sets. In this paper, we descuss how to visualize and understand the content of such reduced data sets.

  2. Feedback Quantization for Linear Precoded Spatial Multiplexing

    NARCIS (Netherlands)

    Simon, C.; Leus, G.

    2008-01-01

    This paper gives an overview and a comparison of recent feedback quantization schemes for linear precoded spatial multiplexing systems. In addition, feedback compression methods are presented that exploit the time correlation of the channel. These methods can be roughly divided into two classes. The

  3. A Krein Quantization Approach to Klein Paradox

    CERN Document Server

    Payandeh, Farrin; Fathi, Mohsen; Moghaddam, Zahra Gh

    2013-01-01

    In this paper we first introduce the famous Klein paradox. Afterwards by proposing the Krein quantization approach and taking the negative modes into account, we will show that the expected and exact current densities, could be achieved without confronting any paradox.

  4. Causal random geometry from stochastic quantization

    DEFF Research Database (Denmark)

    Ambjørn, Jan; Loll, R.; Westra, W.

    2010-01-01

     in this short note we review a recently found formulation of two-dimensional causal quantum gravity defined through Causal Dynamical Triangulations and stochastic quantization. This procedure enables one to extract the nonperturbative quantum Hamiltonian of the random surface model including the...

  5. Effects of quantization on detrended fluctuation analysis

    Institute of Scientific and Technical Information of China (English)

    Zhu Song-Sheng; Xu Ze-Xi; Yin Kui-Xi; Xu Yin-Lin

    2011-01-01

    Detrended fluctuation analysis (DFA) is a method foro estimating the long-range power-law correlation exponent in noisy signals. It has been used successfully in many different fields, especially in the research of physiological signals.As an inherent part of these studies, quantization of continuous signals is inevitable. In addition, coarse-graining, to transfer original signals into symbol series in symbolic dynamic analysis, can also be considered as a quantization-like operation. Therefore, it is worth considering whether the quantization of signal has any effect on the result of DFA and if so, how large the effect will be. In this paper we study how the quantized degrees for three types of noise series (anti-correlated, uncorrelated and long-range power-law correlated signals) affect the results of DFA and find that their effects are completely different. The conclusion has an essential value in choosing the resolution of data acquisition instrument and in the processing of coarse-graining of signals.

  6. Discontinuities and hysteresis in quantized average consensus

    NARCIS (Netherlands)

    Ceragioli, Francesca; Persis, Claudio De; Frasca, Paolo

    2011-01-01

    We consider continuous-time average consensus dynamics in which the agents’ states are communicated through uniform quantizers. Solutions to the resulting system are defined in the Krasowskii sense and are proven to converge to conditions of ‘‘practical consensus’’. To cope with undesired chattering

  7. Hysteresis in a quantized superfluid 'atomtronic' circuit.

    Science.gov (United States)

    Eckel, Stephen; Lee, Jeffrey G; Jendrzejewski, Fred; Murray, Noel; Clark, Charles W; Lobb, Christopher J; Phillips, William D; Edwards, Mark; Campbell, Gretchen K

    2014-02-13

    Atomtronics is an emerging interdisciplinary field that seeks to develop new functional methods by creating devices and circuits where ultracold atoms, often superfluids, have a role analogous to that of electrons in electronics. Hysteresis is widely used in electronic circuits-it is routinely observed in superconducting circuits and is essential in radio-frequency superconducting quantum interference devices. Furthermore, it is as fundamental to superfluidity (and superconductivity) as quantized persistent currents, critical velocity and Josephson effects. Nevertheless, despite multiple theoretical predictions, hysteresis has not been previously observed in any superfluid, atomic-gas Bose-Einstein condensate. Here we directly detect hysteresis between quantized circulation states in an atomtronic circuit formed from a ring of superfluid Bose-Einstein condensate obstructed by a rotating weak link (a region of low atomic density). This contrasts with previous experiments on superfluid liquid helium where hysteresis was observed directly in systems in which the quantization of flow could not be observed, and indirectly in systems that showed quantized flow. Our techniques allow us to tune the size of the hysteresis loop and to consider the fundamental excitations that accompany hysteresis. The results suggest that the relevant excitations involved in hysteresis are vortices, and indicate that dissipation has an important role in the dynamics. Controlled hysteresis in atomtronic circuits may prove to be a crucial feature for the development of practical devices, just as it has in electronic circuits such as memories, digital noise filters (for example Schmitt triggers) and magnetometers (for example superconducting quantum interference devices).

  8. Generalized Derivative Based Kernelized Learning Vector Quantization

    NARCIS (Netherlands)

    Schleif, Frank-Michael; Villmann, Thomas; Hammer, Barbara; Schneider, Petra; Biehl, Michael; Fyfe, Colin; Tino, Peter; Charles, Darryl; Garcia-Osoro, Cesar; Yin, Hujun

    2010-01-01

    We derive a novel derivative based version of kernelized Generalized Learning Vector Quantization (KGLVQ) as an effective, easy to interpret, prototype based and kernelized classifier. It is called D-KGLVQ and we provide generalization error bounds, experimental results on real world data, showing t

  9. Postprocessing MPEG based on estimated quantization parameters

    DEFF Research Database (Denmark)

    Forchhammer, Søren

    2009-01-01

    Postprocessing of MPEG(-2) video is widely used to attenuate the coding artifacts, especially deblocking but also deringing have been addressed. The focus has been on filters where the decoder has access to the code stream and e.g. utilizes information about the quantization parameter. We consider...

  10. Multiverse in the Third Quantized Formalism

    CERN Document Server

    Faizal, Mir

    2014-01-01

    In this paper we will analyze the third quantization of gravity in path integral formalism. We will use the time-dependent version of Wheeler-DeWitt equation to analyze the multiverse in this formalism. We will propose a mechanism for baryogenesis to occurs in the multiverse, without violating the baryon number conservation.

  11. Multiverse in the Third Quantized Formalism

    Science.gov (United States)

    Mir, Faizal

    2014-11-01

    In this paper we will analyze the third quantization of gravity in path integral formalism. We will use the time-dependent version of Wheeler—DeWitt equation to analyze the multiverse in this formalism. We will propose a mechanism for baryogenesis to occur in the multiverse, without violating the baryon number conservation.

  12. Vector-Quantization using Information Theoretic Concepts

    DEFF Research Database (Denmark)

    Lehn-Schiøler, Tue; Hegde, Anant; Erdogmus, Deniz

    2005-01-01

    The process of representing a large data set with a smaller number of vectors in the best possible way, also known as vector quantization, has been intensively studied in the recent years. Very efficient algorithms like the Kohonen Self Organizing Map (SOM) and the Linde Buzo Gray (LBG) algorithm...

  13. Toeplitz Quantization and Asymptotic Expansions: Geometric Construction

    Directory of Open Access Journals (Sweden)

    Miroslav Englis

    2009-02-01

    Full Text Available For a real symmetric domain G_R/K_R, with complexification G_C/K_C, we introduce the concept of ''star-restriction'' (a real analogue of the ''star-products'' for quantization of Kähler manifolds and give a geometric construction of the G_R-invariant differential operators yielding its asymptotic expansion.

  14. Field quantization in inhomogeneous absorptive dielectrics

    NARCIS (Netherlands)

    Suttorp, L.G.; Wubs, Martijn

    2004-01-01

    The quantization of the electromagnetic field in a three-dimensional inhomogeneous dielectric medium with losses is carried out in the framework of a damped-polariton model with an arbitrary spatial dependence of its parameters. The equations of motion for the canonical variables are solved explicit

  15. Modified triplectic quantization in general coordinates

    CERN Document Server

    Geyer, B

    2003-01-01

    We present an extension of previous results (hep-th/0105215)on the quantization of general gauge theories within the BRST-antBRST invatiant Lagrangian scheme in general coordinates, namely, we consider the case when the base manifold of fields and antifields is a supermanifold desribed in terms of both bosonic and fermionic variables.

  16. Superfield quantization of general gauge theories

    CERN Document Server

    Lavrov, P M

    1995-01-01

    A superfield version on superspace (x^\\mu,\\theta^a) is proposed for the Sp(2)-- covariant Lagrangian quantization of general gauge theories. The BRST- and antiBRST- transformations are realized on superfields as supertranslations in the \\theta^a-- directions. A new (geometric) interpretation of the Ward identities in the quantum gauge theory is given.

  17. A Modified Scheme of Triplectic Quantization

    CERN Document Server

    Geyer, B; Lavrov, P M

    1999-01-01

    A modified version of triplectic quantization, first introduce by Batalin and Martnelius, is proposed which makes use of two independent master equations, one for the action and one for the gauge functional such that the initial classical action also obeys that master equation.

  18. A review of learning vector quantization classifiers

    CERN Document Server

    Nova, David

    2015-01-01

    In this work we present a review of the state of the art of Learning Vector Quantization (LVQ) classifiers. A taxonomy is proposed which integrates the most relevant LVQ approaches to date. The main concepts associated with modern LVQ approaches are defined. A comparison is made among eleven LVQ classifiers using one real-world and two artificial datasets.

  19. Lossless image data sequence compression using optimal context quantization

    DEFF Research Database (Denmark)

    Forchhammer, Søren; WU, Xiaolin; Andersen, Jakob Dahl

    2001-01-01

    conditioning states. A solution giving the minimum adaptive code length for a given data set is presented (when the cost of the context quantizer is neglected). The resulting context quantizers can be used for sequential coding of the sequence X0, X1, X 2, …. A coding scheme based on binary decomposition...... and context quantization for coding the binary decisions is presented and applied to digital maps and α-plane sequences. The optimal context quantization is also used to evaluate existing heuristic context quantizations....

  20. Integrated Advanced Microwave Sounding Unit-A (AMSU-A). As-Designed Parts List: Electrical, Electronic and Electromechanical (EEE) As-Designed Parts List

    Science.gov (United States)

    Lorenz, E.

    1999-01-01

    This report comprises the Electrical, Electronic, and Electromechanical (EEE) As Designed Parts List to be used in the Integrated Advanced Microwave Sounding Unit-A (AMSU-A) instrument. The purpose of the EEE As-Designed Parts List is to provide a listing of EEE parts identified for use on the Integrated AMSU-A. All EEE parts used on the AMSU-A must meet the parts control requirements as defined in the Parts Control Plan (POP). All part applications are reviewed by the Parts Control Board (PCB) and granted approval if POP requirements are met. The "As Designed Parts Lists" indicates PCB approval status, and thus also serves as the Program Approved Parts List.

  1. Polymer Quantization predicts radiation in inertial frames

    CERN Document Server

    Kajuri, Nirmalya

    2015-01-01

    We investigate the response of an Unruh-DeWitt detector coupled to a polymer quantized massless scalar field in flat spacetime, using the propagator obtained by Hossain, Husain and Seahra. As this propagator violates Lorentz invariance, frames moving at different constant velocities are no longer equivalent. This means that it is possible in principle for even an observer moving at constant velocity to detect radiation. We show that such an observer indeed detects radiation. Remarkably, we show that the rate of this radiation does not decrease with the decrease in the characteristic length scale of polymer quantization. Thus the radiation cannot be suppressed by making the polymer length scale arbitrarily small. Our results should bring this theory within the ambit of low-energy experiments and place a lower limit on the characteristic polymer length scale.

  2. A Counterexample to the Quantizability of Modules

    CERN Document Server

    Willwacher, Thomas

    2007-01-01

    Let a Poisson structure on a manifold M be given. If it vanishes at a point m, the evaluation at m defines a one dimensional representation of the Poisson algebra of functions on M. We show that this representation can, in general, not be quantized. Precisely, we give a counterexample for M=R^n, such that: (i) The evaluation map at 0 can not be quantized to a representation of the algebra of functions with product the Kontsevich product associated to the Poisson structure. (ii) For any formal Poisson structure extending the given one and vanishing at zero up to second order in epsilon, (i) still holds. We do not know whether the second claim remains true if one allows the higher order terms in epsilon to attain nonzero values at zero.

  3. Quantization of rotating linear dilaton black holes

    CERN Document Server

    Sakalli, I

    2014-01-01

    In this paper, we firstly prove that the adiabatic invariant quantity, which is commonly used in the literature for quantizing the rotating black holes (BHs) is fallacious. We then show how its corrected form should be. The main purpose of this paper is to study the quantization of 4-dimensional rotating linear dilaton black hole (RLDBH) spacetime describing with an action, which emerges in the Einstein-Maxwell-Dilaton-Axion (EMDA) theory. The RLDBH spacetime has a non-asymptotically flat (NAF) geometry. They reduces to the linear dilaton black hole (LDBH) metric when vanishing its rotation parameter "a". While studying its scalar perturbations, it is shown that the Schr\\"odinger-like wave equation around the event horizon reduces to a confluent hypergeometric differential equation. Then the associated complex frequencies of the quasinormal modes (QNMs) are computed. By using those QNMs in the true definition of the rotational adiabatic invariant quantity, we obtain the quantum spectra of entropy/area for the...

  4. Light-Front quantization of field theory

    CERN Document Server

    Srivastava, P P

    1996-01-01

    Some basic topics in Light-Front (LF) quantized field theory are reviewed. Poincarè algebra and the LF Spin operator are discussed. The local scalar field theory of the conventional framework is shown to correspond to a non-local Hamiltonian theory on the LF in view of the constraint equations on the phase space, which relate the bosonic condensates to the non-zero modes. This new ingredient is useful to describe the spontaneous symmetry breaking on the LF. The instability of the symmetric phase in two dimensional scalar theory when the coupling constant grows is shown in the LF theory renormalized to one loop order. Chern-Simons gauge theory regarded to describe excitations with fractional statistics, is quantized in the light-cone gauge and a simple LF Hamiltonian obtained which may allow us to construct renormalized theory of anyons.

  5. Chaos, Dirac observables and constraint quantization

    CERN Document Server

    Dittrich, Bianca; Koslowski, Tim A; Nelson, Mike I

    2015-01-01

    There is good evidence that full general relativity is non-integrable or even chaotic. We point out the severe repercussions: differentiable Dirac observables and a reduced phase space do not exist in non-integrable constrained systems and are thus unlikely to occur in a generic general relativistic context. Instead, gauge invariant quantities generally become discontinuous, thus not admitting Poisson-algebraic structures and posing serious challenges to a quantization. Non-integrability also renders the paradigm of relational dynamics cumbersome, thereby straining common interpretations of the dynamics. We illustrate these conceptual and technical challenges with simple toy models. In particular, we exhibit reparametrization invariant models which fail to be integrable and, as a consequence, can either not be quantized with standard methods or lead to sick quantum theories without a semiclassical limit. These troubles are qualitatively distinct from semiclassical subtleties in unconstrained quantum chaos and...

  6. Von Neumann's Quantization of General Relativity

    CERN Document Server

    Arbuzov, A B; Cirilo-Lombardo, D J; Nazmitdinov, R G; Han, Nguyen Suan; Pavlov, A E; Pervushin, V N; Zakharov, A F

    2015-01-01

    Von Neumann's procedure is applied for quantization of General Relativity. We quantize the initial data of dynamical variables at the Planck epoch, where the Hubble parameter coincides with the Planck mass. These initial data are defined via the Fock simplex in the tangent Minkowskian space-time, the Dirac conformal interval. The Einstein cosmological principle is applied for the average of the spatial metric determinant logarithm over the spatial volume of the visible Universe. We derive the splitting of the general coordinate transformations into the diffeomorphisms (as the object of the second Noether theorem) and the initial data transformations (as objects of the first Noether theorem). Following von Neumann, we suppose that the vacuum state is a quantum ensemble. The vacuum state is degenerated with respect to quantum numbers of non-vacuum states with the distribution function that yields the Casimir effect in gravidynamics in analogy to the one in electrodynamics. The generation functional of the pertu...

  7. The problem of quantization of lightcone QCD

    CERN Document Server

    Popov, Alexey V

    2011-01-01

    There exists the problem to construct a quantum algebra of observables in lightcone QCD beyond the perturbative regime. It has recently established that the boundary gauge fields are crucial for a consistent construction of the classical dynamic system. If the gauge group is non-Abelian and there are four or more space-time dimensions then the procedure of symplectic reduction gives a classical dynamical system with very complicated Hamiltonian having infinite power over the coupling constant. Then, to quantize the theory one should to construct a Poisson algebra and to quantize it. Careful analysis shows that a Poisson formulation has a problem with: canonical commutation relations, spatial invariance, and the boundary degrees of freedom in the Hamiltonian.

  8. Vector Potential Quantization and the Quantum Vacuum

    Directory of Open Access Journals (Sweden)

    Constantin Meis

    2014-01-01

    Full Text Available We investigate the quantization of the vector potential amplitude of the electromagnetic field to a single photon state starting from the fundamental link equations between the classical electromagnetic theory and the quantum mechanical expressions. The resulting wave-particle formalism ensures a coherent transition between the classical electromagnetic wave theory and the quantum representation. A quantization constant of the photon vector potential is defined. A new quantum vacuum description results directly in having very low energy density. The calculated spontaneous emission rate and Lambs shift for the nS states of the hydrogen atom are in agreement with quantum electrodynamics. This low energy quantum vacuum state might be compatible with recent astrophysical observations.

  9. Scalets, wavelets and (complex) turning point quantization

    Science.gov (United States)

    Handy, C. R.; Brooks, H. A.

    2001-05-01

    Despite the many successes of wavelet analysis in image and signal processing, the incorporation of continuous wavelet transform theory within quantum mechanics has lacked a compelling, first principles, motivating analytical framework, until now. For arbitrary one-dimensional rational fraction Hamiltonians, we develop a simple, unified formalism, which clearly underscores the complementary, and mutually interdependent, role played by moment quantization theory (i.e. via scalets, as defined herein) and wavelets. This analysis involves no approximation of the Hamiltonian within the (equivalent) wavelet space, and emphasizes the importance of (complex) multiple turning point contributions in the quantization process. We apply the method to three illustrative examples. These include the (double-well) quartic anharmonic oscillator potential problem, V(x) = Z2x2 + gx4, the quartic potential, V(x) = x4, and the very interesting and significant non-Hermitian potential V(x) = -(ix)3, recently studied by Bender and Boettcher.

  10. Loop quantization of the Schwarzschild black hole.

    Science.gov (United States)

    Gambini, Rodolfo; Pullin, Jorge

    2013-05-24

    We quantize spherically symmetric vacuum gravity without gauge fixing the diffeomorphism constraint. Through a rescaling, we make the algebra of Hamiltonian constraints Abelian, and therefore the constraint algebra is a true Lie algebra. This allows the completion of the Dirac quantization procedure using loop quantum gravity techniques. We can construct explicitly the exact solutions of the physical Hilbert space annihilated by all constraints. New observables living in the bulk appear at the quantum level (analogous to spin in quantum mechanics) that are not present at the classical level and are associated with the discrete nature of the spin network states of loop quantum gravity. The resulting quantum space-times resolve the singularity present in the classical theory inside black holes.

  11. Loop quantization of the Schwarzschild interior revisited

    CERN Document Server

    Corichi, Alejandro

    2015-01-01

    The loop quantization of the Schwarzschild interior region, as described by a homogenous anisotropic Kantowski-Sachs model, is re-examined. As several studies of different --inequivalent-- loop quantizations have shown, to date there exists no fully satisfactory quantum theory for this model. This fact posses challenges to the validity of some scenarios to address the black hole information problem. Here we put forward a novel viewpoint to construct the quantum theory that builds from some of the models available in the literature. The final picture is a quantum theory that is both independent of any auxiliary structure and possesses a correct low curvature limit. It represents a subtle but non-trivial modification of the original prescription given by Ashtekar and Bojowald. It is shown that the quantum gravitational constraint is well defined past the singularity and that its effective dynamics possesses a bounce into an expanding regime. The classical singularity is avoided, and a semiclassical spacetime sa...

  12. Phase-Quantized Block Noncoherent Communication

    CERN Document Server

    Singh, Jaspreet

    2011-01-01

    Analog-to-digital conversion (ADC) is a key bottleneck in scaling DSP-centric receiver architectures to multiGigabit/s speeds. Recent information-theoretic results, obtained under ideal channel conditions (perfect synchronization, no dispersion), indicate that low-precision ADC (1-4 bits) could be a suitable choice for designing such high speed systems. In this work, we study the impact of employing low-precision ADC in a {\\it carrier asynchronous} system. Specifically, we consider transmission over the block noncoherent Additive White Gaussian Noise (AWGN) channel, and investigate the achievable performance under low-precision output quantization. We focus attention on an architecture in which the receiver quantizes {\\it only the phase} of the received signal: this has the advantage of being implementable without automatic gain control, using multiple 1-bit ADCs preceded by analog multipliers. For standard uniform Phase Shift Keying (PSK) modulation, we study the structure of the transition density of the re...

  13. The quantization of gravity an introduction

    CERN Document Server

    Wallace, D

    2000-01-01

    This is an introduction to quantum gravity, aimed at a fairly general audience and concentrating on what have historically two main approaches to quantum gravity: the covariant and canonical programs (string theory is not covered). The quantization of gravity is discussed by analogy with the quantization of the electromagnetic field. The conceptual and technical problems of both approaches are discussed, and the paper concludes with a discussion of evidence for quantum gravity from the rest of physics. The paper assumes some familiarity with non-relativistic quantum mechanics, special relativity, and the Lagrangian and Hamiltonian formulations of classical mechanics; some experience with classical field theory, quantum electrodynamics and the gauge principle in electromagnetism might be helpful but is not required. No knowledge of general relativity or of quantum field theory in general is assumed.

  14. Enhanced photoredox chemistry in quantized semiconductor colloids

    Energy Technology Data Exchange (ETDEWEB)

    Nedeljkovic, J.M.; Nenadovic, M.T.; Micic, O.I.; Nozik, A.J.

    1986-01-02

    Optical effects due to size quantization have been observed for HgSe, PbSe, and CdSe colloids in water and acetonitrile with particle diameters of 20-100 A. For diameters less than 50 A, the optical absorption edge of HgSe and PbSe is blue shifted by several volts. The results are consistent with perturbation of the semiconductor band structure due to carrier confinement in very small particles resulting in an increase in the effective band gap. The redox potential of photogenerated carriers is greatly enhanced in such quantized semiconductor particles; reduction reactions that cannot occur in bulk materials can occur in sufficiently small particles. This has been demonstrated with H/sub 2/ evolution in 50-A PbSe and HgSe colloids and CO/sub 2/ reduction in 50-A CdSe colloids. 13 references, 3 figures.

  15. Foundations of quantization for probability distributions

    CERN Document Server

    Graf, Siegfried

    2000-01-01

    Due to the rapidly increasing need for methods of data compression, quantization has become a flourishing field in signal and image processing and information theory. The same techniques are also used in statistics (cluster analysis), pattern recognition, and operations research (optimal location of service centers). The book gives the first mathematically rigorous account of the fundamental theory underlying these applications. The emphasis is on the asymptotics of quantization errors for absolutely continuous and special classes of singular probabilities (surface measures, self-similar measures) presenting some new results for the first time. Written for researchers and graduate students in probability theory the monograph is of potential interest to all people working in the disciplines mentioned above.

  16. Gauge invariance and Weyl-polymer quantization

    CERN Document Server

    Strocchi, Franco

    2016-01-01

    The book gives an introduction to Weyl non-regular quantization suitable for the description of physically interesting quantum systems, where the traditional Dirac-Heisenberg quantization is not applicable.  The latter implicitly assumes that the canonical variables describe observables, entailing necessarily the regularity of their exponentials (Weyl operators). However, in physically interesting cases -- typically in the presence of a gauge symmetry -- non-observable canonical variables are introduced for the description of the states, namely of the relevant representations of the observable algebra. In general, a gauge invariant ground state defines a non-regular representation of the gauge dependent Weyl operators, providing a mathematically consistent treatment of familiar quantum systems -- such as the electron in a periodic potential (Bloch electron), the Quantum Hall electron, or the quantum particle on a circle -- where the gauge transformations are, respectively, the lattice translations, the magne...

  17. Lattice Radial Quantization: 3D Ising

    CERN Document Server

    Brower, Richard; Neuberger, Herbert

    2012-01-01

    Lattice radial quantization is introduced as a nonperturbative method intended to numerically solve Euclidean conformal field theories that can be realized as fixed points of known Lagrangians. As an example, we employ a lattice shaped as a cylinder with a 2D Icosahedral cross-section to discretize dilatations in the 3D Ising model. Using this method, we obtain the preliminary estimate eta=0.034(10).

  18. Analog-digital codesign using coarse quantization

    Science.gov (United States)

    Kokkeler, Andre Bernardus Joseph

    With regards to electronic systems, two important trends can be observed. The first trend is generally known as Moore's law: the digital processing capacity per chip is increasing a factor two every 18 months. Another part of the first trend is that the performance increase of integrated linear or analog processing is slow, a factor two every 4.7 years. The second trend is that the rate of data exchange between electronic systems is increasing rapidly. Because of these high data rates especially the design of data converters from analog to digital (ADCs) is demanding. For a specific set of applications, the requirements for the ADC can be relaxed by reducing the resolution of the conversion from analog to digital. Within these specific applications, signal characteristics rather than instantaneous values of the signal are determined. Reducing the resolution to an extreme extend is called 'coarse quantization'. The design of mixed signal systems is guided by a Y-chart design methodology. Analog-Digital Codesign, guided by the Y-chart approach, leads to mixed-signal systems with reduced costs compared to systems designed with the traditional methodology. The Y-chart approach also enables the use of coarse quantization as an additional design parameter to further reduce costs. This is illustrated by two case studies. The first case study concentrates on the design of a digital predistorter for Power Amplifiers (PAs) in telecommunication transmitters. In the second case study, we reconsider the design of a part of a Radio Telescope, used for Radio Astronomy. This part is called the Tied Array Adder and it sums signals from different telescopes. Both case studies show that coarse quantization can lead to mixed-signal systems with lower costs but system parameters will change. The explicit reconsideration of functional specifications, facilitated by the Y-chart approach, is therefore essential for the introduction of coarse quantization.

  19. Covariant quantization of the CBS superparticle

    Energy Technology Data Exchange (ETDEWEB)

    Grassi, P.A. E-mail: pag5@nyu.edu; Policastro, G.; Porrati, M

    2001-07-09

    The quantization of the Casalbuoni-Brink-Schwarz superparticle is performed in an explicitly covariant way using the antibracket formalism. Since an infinite number of ghost fields are required, within a suitable off-shell twistor-like formalism, we are able to fix the gauge of each ghost sector without modifying the physical content of the theory. The computation reveals that the antibracket cohomology contains only the physical degrees of freedom.

  20. Isomonodromic quantization of dimensionally reduced gravity

    OpenAIRE

    Korotkin, D.; Nicolai, H.

    1996-01-01

    We present a detailed account of the isomonodromic quantization of dimensionally reduced Einstein gravity with two commuting Killing vectors. This theory constitutes an integrable ``midi-superspace" version of quantum gravity with infinitely many interacting physical degrees of freedom. The canonical treatment is based on the complete separation of variables in the isomonodromic sectors of the model. The Wheeler-DeWitt and diffeomorphism constraints are thereby reduced to the Knizhnik-Zamolod...

  1. Geometry and quantization of moduli spaces

    CERN Document Server

    Andersen, Jørgen; Riera, Ignasi

    2016-01-01

    This volume is based on four advanced courses held at the Centre de Recerca Matemàtica (CRM), Barcelona. It presents both background information and recent developments on selected topics that are experiencing extraordinary growth within the broad research area of geometry and quantization of moduli spaces. The lectures focus on the geometry of moduli spaces which are mostly associated to compact Riemann surfaces, and are presented from both classical and quantum perspectives.

  2. Baby Skyrmions stabilized by canonical quantization

    Energy Technology Data Exchange (ETDEWEB)

    Acus, A.; Norvaisas, E. [Vilnius University, Institute of Theoretical Physics and Astronomy, Gostauto 12, Vilnius 01108 (Lithuania); Shnir, Ya., E-mail: shnir@maths.tcd.i [School of Theoretical Physics - DIAS, 10 Burlington Road, Dublin 4 (Ireland); Institute of Physics, Jagiellonian University, Krakow (Poland)

    2009-11-23

    We analyse the effect of the canonical quantization of the rotational mode of the O(3)sigma-model which includes the Skyrme term. Numerical evidence is presented that the quantum correction to the mass of the rotationally-invariant charge n=1,2 configurations may stabilize the solution even in the limit of vanishing potential. The corresponding range of values of the parameters is discussed.

  3. Baby Skyrmions stabilized by canonical quantization

    CERN Document Server

    Acus, A; Shnir, Ya

    2009-01-01

    We analyse the effect of the canonical quantization of the rotational mode of the O(3) $\\sigma$-model which includes the Skyrme term. Numerical evidence is presented that the quantum correction to the mass of the rotationally-invariant charge $n=1,2$ configurations may stabilize the solution even in the limit of vanishing potential. The corresponding range of values of the parameters is discussed.

  4. Homotopy arguments for quantized Hall conductivity

    CERN Document Server

    Richter, T

    2002-01-01

    Using the strong localization bounds obtained by the Aizenman-Molcanov method for a particle in a magnetic field and a disordered potential, we show that the zero-temperature Hall conductivity of a gas of such particles is quantized and constant as long as both Fermi energy and disorder coupling parameter vary in a region of strong localization of the corresponding two-dimensional phase diagram.

  5. String Quantization and the Shuffle Hopf Algebra

    CERN Document Server

    Bahns, Dorothea

    2011-01-01

    The Poisson algebra $\\mathfrak h$ of invariants of the Nambu-Goto string, which was first introduced by K. Pohlmeyer in 1982, is described using the Shuffle Hopf algebra. In particular, an underlying auxiliary Lie algebra is reformulated in terms of the image of the first Eulerian idempotent of the Shuffle Hopf algebra. This facilitates the comparison of different approaches to the quantization of $\\mathfrak h$.

  6. Superfield quantization in Sp(2) covariant formalism

    CERN Document Server

    Lavrov, P M

    2001-01-01

    The rules of the superfield Sp(2) covariant quantization of the arbitrary gauge theories for the case of the introduction of the gauging with the derivative equations for the gauge functional are generalized. The possibilities of realization of the expanded anti-brackets are considered and it is shown, that only one of the realizations is compatible with the transformations of the expanded BRST-symmetry in the form of super translations along the Grassmann superspace coordinates

  7. Gauge models in modified triplectic quantization

    CERN Document Server

    Geyer, B; Moshin, P Y; Geyer, Bodo; Lavrov, Petr M.; Moshin, Pavel Yu.

    2001-01-01

    We apply the modified triplectic formalism for quantizing several popular gauge models - non-abelian antisymmetric tensor field model, W2-gravity and two-dimensional gravity with dynamical torsion. The explicit solutions are obtained for the generating equations of the quantum action and the gauge-fixing functional. Using these solutions we construct the vacuum functional and obtain the corresponding transformations of the extended BRST symmetry.

  8. Quantized Nanocrystalline CdTe Thin Films

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Nanocrystalline CdTe thin films were prepared by asymmetric rectangular pulse electrodeposition in organic solution at 110°C. STM image shows a porous network morphology constructed by interconnected spherical CdTe crystallites with a mean diameter of 4.2 nm. A pronounced size quantization was indicated in the action and absorption spectra. Potentials dependence dual conductive behavior was revealed in the photocurrent-potential (I-V) curves.

  9. Covariant quantization of the CBS superparticle

    Science.gov (United States)

    Grassi, P. A.; Policastro, G.; Porrati, M.

    2001-07-01

    The quantization of the Casalbuoni-Brink-Schwarz superparticle is performed in an explicitly covariant way using the antibracket formalism. Since an infinite number of ghost fields are required, within a suitable off-shell twistor-like formalism, we are able to fix the gauge of each ghost sector without modifying the physical content of the theory. The computation reveals that the antibracket cohomology contains only the physical degrees of freedom.

  10. Conductance Quantization in Resistive Random Access Memory.

    Science.gov (United States)

    Li, Yang; Long, Shibing; Liu, Yang; Hu, Chen; Teng, Jiao; Liu, Qi; Lv, Hangbing; Suñé, Jordi; Liu, Ming

    2015-12-01

    The intrinsic scaling-down ability, simple metal-insulator-metal (MIM) sandwich structure, excellent performances, and complementary metal-oxide-semiconductor (CMOS) technology-compatible fabrication processes make resistive random access memory (RRAM) one of the most promising candidates for the next-generation memory. The RRAM device also exhibits rich electrical, thermal, magnetic, and optical effects, in close correlation with the abundant resistive switching (RS) materials, metal-oxide interface, and multiple RS mechanisms including the formation/rupture of nanoscale to atomic-sized conductive filament (CF) incorporated in RS layer. Conductance quantization effect has been observed in the atomic-sized CF in RRAM, which provides a good opportunity to deeply investigate the RS mechanism in mesoscopic dimension. In this review paper, the operating principles of RRAM are introduced first, followed by the summarization of the basic conductance quantization phenomenon in RRAM and the related RS mechanisms, device structures, and material system. Then, we discuss the theory and modeling of quantum transport in RRAM. Finally, we present the opportunities and challenges in quantized RRAM devices and our views on the future prospects.

  11. Conductance Quantization in Resistive Random Access Memory

    Science.gov (United States)

    Li, Yang; Long, Shibing; Liu, Yang; Hu, Chen; Teng, Jiao; Liu, Qi; Lv, Hangbing; Suñé, Jordi; Liu, Ming

    2015-10-01

    The intrinsic scaling-down ability, simple metal-insulator-metal (MIM) sandwich structure, excellent performances, and complementary metal-oxide-semiconductor (CMOS) technology-compatible fabrication processes make resistive random access memory (RRAM) one of the most promising candidates for the next-generation memory. The RRAM device also exhibits rich electrical, thermal, magnetic, and optical effects, in close correlation with the abundant resistive switching (RS) materials, metal-oxide interface, and multiple RS mechanisms including the formation/rupture of nanoscale to atomic-sized conductive filament (CF) incorporated in RS layer. Conductance quantization effect has been observed in the atomic-sized CF in RRAM, which provides a good opportunity to deeply investigate the RS mechanism in mesoscopic dimension. In this review paper, the operating principles of RRAM are introduced first, followed by the summarization of the basic conductance quantization phenomenon in RRAM and the related RS mechanisms, device structures, and material system. Then, we discuss the theory and modeling of quantum transport in RRAM. Finally, we present the opportunities and challenges in quantized RRAM devices and our views on the future prospects.

  12. Light-Front Quantization of Gauge Theories

    Energy Technology Data Exchange (ETDEWEB)

    Brodskey, Stanley

    2002-12-01

    Light-front wavefunctions provide a frame-independent representation of hadrons in terms of their physical quark and gluon degrees of freedom. The light-front Hamiltonian formalism provides new nonperturbative methods for obtaining the QCD spectrum and eigensolutions, including resolvant methods, variational techniques, and discretized light-front quantization. A new method for quantizing gauge theories in light-cone gauge using Dirac brackets to implement constraints is presented. In the case of the electroweak theory, this method of light-front quantization leads to a unitary and renormalizable theory of massive gauge particles, automatically incorporating the Lorentz and 't Hooft conditions as well as the Goldstone boson equivalence theorem. Spontaneous symmetry breaking is represented by the appearance of zero modes of the Higgs field leaving the light-front vacuum equal to the perturbative vacuum. I also discuss an ''event amplitude generator'' for automatically computing renormalized amplitudes in perturbation theory. The importance of final-state interactions for the interpretation of diffraction, shadowing, and single-spin asymmetries in inclusive reactions such as deep inelastic lepton-hadron scattering is emphasized.

  13. Quantized Network Coding for Sparse Messages

    CERN Document Server

    Nabaee, Mahdy

    2012-01-01

    In this paper, we study the data gathering problem in the context of power grids by using a network of sensors, where the sensed data have inter-node redundancy. Specifically, we propose a new transmission method, calledquantized network coding, which performs linear net-work coding in the field of real numbers, and quantization to accommodate the finite capacity of edges. By using the concepts in compressed sensing literature, we propose to use l1-minimization to decode the quantized network coded packets, especially when the number of received packets at the decoder is less than the size of sensed data (i.e. number of nodes). We also propose an appropriate design for network coding coefficients, based on restricted isometry property, which results in robust l1-min decoding. Our numerical analysis show that the proposed quantized network coding scheme with l1-min decoding can achieve significant improvements, in terms of compression ratio and delivery delay, compared to conventional packet forwarding.

  14. Review on the quantization of gravity

    CERN Document Server

    Schulz, Benjamin

    2014-01-01

    This is a review article on quantum gravity. In section 1, the Penrose singularity theorem is proven. In section 2, the covariant quantization approach of gravity is reviewed. In section 3, an article by Hawking is reviewed that shows the gravitational path integral at one loop level to be dominated by contributions from some kind of virtual gravitational instantons. In section 4, the canonical, non-perturbative quantization approach is reviewed. In section 5, arguments from Hawking are mentioned which show the gravitational path integral to be an approximate solution of the Wheeler deWitt equation. In section 6, the black hole entropy is derived in various ways. Section 6.1 uses the gravitational path integral for this calculation. Section 6.2 shows how the black hole entropy can be derived from canonical quantum gravity. In section 7.1, arguments from Dvali and Gomez who claim that gravity can be quantized in a way which would be in some sense self-complete are critically assessed. In section 7.2 a model fr...

  15. Weak gauge principle and electric charge quantization

    CERN Document Server

    Minguzzi, E; Almorox, A L

    2006-01-01

    We review the argument that relates the quantization of electric charge to the topology of the spacetime manifold starting from the gauge principle. We formulate it in the language of Cech cohomology so that its generalization to cases that do not involve a monopole field becomes straightforward. We consider two different formulations of the gauge principle, the usual (strong) version and a weaker version in which the transition functions can differ from matter field to matter field. From both versions it follows that the charges are quantized if the electromagnetic field is not exact. The weak case is studied in detail. To each pair of particles there corresponds an interference class $k \\in H^{1}(M,U(1))$ that controls the different behavior of the particles under topological Aharonov-Bohm experiments. If this class is trivial the phenomenology reduces to that of the usual strong gauge principle case. It is shown that the theory may give rise to two natural quantization units that we identify with the quant...

  16. Quantizations of D = 3 Lorentz symmetry

    Energy Technology Data Exchange (ETDEWEB)

    Lukierski, J. [University of Wroclaw, Institute for Theoretical Physics, Wroclaw (Poland); Tolstoy, V.N. [University of Wroclaw, Institute for Theoretical Physics, Wroclaw (Poland); Skobeltsyn Institute of Nuclear Physics, Lomonosov Moscow State University, Moscow (Russian Federation)

    2017-04-15

    Using the isomorphism o(3; C) ≅ sl(2; C) we develop a new simple algebraic technique for complete classification of quantum deformations (the classical r-matrices) for real forms o(3) and o(2,1) of the complex Lie algebra o(3; C) in terms of real forms of sl(2; C): su(2), su(1,1) and sl(2; R). We prove that the D = 3 Lorentz symmetry o(2,1) ≅ su(1,1) ≅ sl(2; R) has three different Hopf-algebraic quantum deformations, which are expressed in the simplest way by two standard su(1,1) and sl(2; R) q-analogs and by simple Jordanian sl(2; R) twist deformation. These quantizations are presented in terms of the quantum Cartan-Weyl generators for the quantized algebras su(1,1) and sl(2; R) as well as in terms of quantum Cartesian generators for the quantized algebra o(2,1). Finally, some applications of the deformed D = 3 Lorentz symmetry are mentioned. (orig.)

  17. Image Vector Quantization codec indexes filtering

    Directory of Open Access Journals (Sweden)

    Lakhdar Moulay Abdelmounaim

    2012-01-01

    Full Text Available Vector Quantisation (VQ is an efficient coding algorithm that has been widely used in the field of video and image coding, due to its fast decoding efficiency. However, the indexes of VQ are sometimes lost because of signal interference during the transmission. In this paper, we propose an efficient estimation method to conceal and recover the lost indexes on the decoder side, to avoid re-transmitting the whole image again. If the image or video has the limitation of a period of validity, re-transmitting the data wastes the resources of time and network bandwidth. Therefore, using the originally received correct data to estimate and recover the lost data is efficient in time-constrained situations, such as network conferencing or mobile transmissions. In nature images, the pixels are correlated with their neighbours and VQ partitions the image into sub-blocks and quantises them to the indexes that are transmitted; the correlation between adjacent indexes is very strong. There are two parts of the proposed method. The first is pre-processing and the second is an estimation process. In pre-processing, we modify the order of codevectors in the VQ codebook to increase the correlation among the neighbouring vectors. We then use a special filtering method in the estimation process. Using conventional VQ to compress the Lena image and transmit it without any loss of index can achieve a PSNR of 30.429 dB on the decoder. The simulation results demonstrate that our method can estimate the indexes to achieve PSNR values of 29.084 and 28.327 dB when the loss rate is 0.5% and 1%, respectively.

  18. Nambu mechanics, $n$-ary operations and their quantization

    CERN Document Server

    Flato, M; Sternheimer, D; Flato, Moshe; Dito, Giuseppe; Sternheimer, Daniel

    1997-01-01

    We start with an overview of the "generalized Hamiltonian dynamics" introduced in 1973 by Y. Nambu, its motivations, mathematical background and subsequent developments -- all of it on the classical level. This includes the notion (not present in Nambu's work) of a generalization of the Jacobi identity called Fundamental Identity. We then briefly describe the difficulties encountered in the quantization of such $n$-ary structures, explain their reason and present the recently obtained solution combining deformation quantization with a "second quantization" type of approach on ${\\Bbb R}^n$. The solution is called "Zariski quantization" because it is based on the factorization of (real) polynomials into irreducibles. Since we want to quantize composition laws of the determinant (Jacobian) type and need a Leibniz rule, we need to take care also of derivatives and this requires going one step further (Taylor developments of polynomials over polynomials). We also discuss a (closer to the root, "first quantized") a...

  19. Quantum-Classical Correspondence of Dynamical Observables, Quantization and the Time of Arrival Correspondence Problem

    CERN Document Server

    Galapon, E A

    2001-01-01

    We raise the problem of constructing quantum observables that have classical counterparts without quantization. Specifically we seek to define and motivate a solution to the quantum-classical correspondence problem independent from quantization and discuss the general insufficiency of prescriptive quantization, particularly the Weyl quantization. We demonstrate our points by constructing time of arrival operators without quantization and from these recover their classical counterparts.

  20. Number-phase quantization of a mesoscopic RLC circuit

    Institute of Scientific and Technical Information of China (English)

    Xu Cheng-Lin

    2012-01-01

    With the help of the time-dependent Lagrangian for a damped harmonic oscillator,the quantization of mesoscopic RLC circuit in the context of a number-phase quantization scheme is realized and the corresponding Hamiltonian operator is obtained.Then the evolution of the charge number and phase diffcrence across the capacity are obtained.It is shown that the number-phase analysis is useful to tackle the quantization of some mesoscopic circuits and dynamical equations of the corresponding operators.

  1. Natural and projectively equivariant quantizations by means of Cartan Connections

    OpenAIRE

    Mathonet, Pierre; Radoux, Fabian

    2006-01-01

    The existence of a natural and projectively equivariant quantization in the sense of Lecomte [20] was proved recently by M. Bordemann [4], using the framework of Thomas-Whitehead connections. We give a new proof of existence using the notion of Cartan projective connections and we obtain an explicit formula in terms of these connections. Our method yields the existence of a projectively equivariant quantization if and only if an \\sl(m+1,\\R)-equivariant quantization exists in the flat situatio...

  2. SWKB Quantization Rules for Bound States in Quantum Wells

    CERN Document Server

    Sinha, A K; Sinha, Anjana; Roychoudhury, Rajkumar

    2000-01-01

    In a recent paper by Gomes and Adhikari (J.Phys B30 5987(1997)) a matrix formulation of the Bohr-Sommerfield quantization rule has been applied to the study of bound states in one dimension quantum wells. Here we study these potentials in the frame work of supersymmetric WKB (SWKB) quantization approximation and find that SWKB quantization rule is superior to the modified Bohr-Sommerfield or WKB rules as it exactly reproduces the eigenenergies.

  3. Double quantization on the coajoint representation of sl(n)

    CERN Document Server

    Donin, J

    1997-01-01

    For $\\g=sl(n)$ we construct a two parametric $U_h(\\g)$-invariant family of algebras, $(S\\g)_{t,h}$, that is a quantization of the function algebra $S\\g$ on the coadjoint representation. Along the parameter $t$ the family gives a quantization of the Lie bracket. This family induces a two parametric $U_h(\\g)$-invariant quantization on the maximal orbits, which includes a quantization of the Kirillov-Kostant-Souriau bracket. Yet we construct a quantum de Rham complex on~$\\g^*$.

  4. Extended Reconstruction Approaches for Saturation Measurements Using Reserved Quantization Indices

    DEFF Research Database (Denmark)

    Li, Peng; Arildsen, Thomas; Larsen, Torben

    2012-01-01

    This paper proposes a reserved quantization indices method for saturated measurements in compressed sensing. The existing approaches tailored for saturation effect do not provide a way to identify saturated measurements, which is mandatory in practical implementations.We introduce a method using...... reserved quantization indices to mark saturated measurements, which is applicable to current quantizer models. Two extended approaches based on the proposed method have been investigated compared to the existing approaches. The investigation shows that saturated measurements can be identified by reserved...... quantization indices without adding extra hardware resources while maintaining a comparable reconstruction quality to the existing approaches....

  5. Topological Quantization in Units of the Fine Structure Constant

    Energy Technology Data Exchange (ETDEWEB)

    Maciejko, Joseph; /Stanford U., Phys. Dept. /Stanford U., Materials Sci. Dept. /SLAC; Qi, Xiao-Liang; /Station Q, UCSB /Stanford U., Phys. Dept. /Stanford U., Materials Sci. Dept. /SLAC; Drew, H.Dennis; /Maryland U.; Zhang, Shou-Cheng; /Stanford U., Phys. Dept. /Stanford U., Materials Sci. Dept. /SLAC

    2011-11-11

    Fundamental topological phenomena in condensed matter physics are associated with a quantized electromagnetic response in units of fundamental constants. Recently, it has been predicted theoretically that the time-reversal invariant topological insulator in three dimensions exhibits a topological magnetoelectric effect quantized in units of the fine structure constant {alpha} = e{sup 2}/{h_bar}c. In this Letter, we propose an optical experiment to directly measure this topological quantization phenomenon, independent of material details. Our proposal also provides a way to measure the half-quantized Hall conductances on the two surfaces of the topological insulator independently of each other.

  6. Semiclassical quantization of nonadiabatic systems with hopping periodic orbits

    Energy Technology Data Exchange (ETDEWEB)

    Fujii, Mikiya, E-mail: mikiya.fujii@gmail.com; Yamashita, Koichi [Department of Chemical System Engineering, School of Engineering, The University of Tokyo, Tokyo 113-8656 (Japan); JST, CREST, Tokyo 113-8656 (Japan)

    2015-02-21

    We present a semiclassical quantization condition, i.e., quantum–classical correspondence, for steady states of nonadiabatic systems consisting of fast and slow degrees of freedom (DOFs) by extending Gutzwiller’s trace formula to a nonadiabatic form. The quantum–classical correspondence indicates that a set of primitive hopping periodic orbits, which are invariant under time evolution in the phase space of the slow DOF, should be quantized. The semiclassical quantization is then applied to a simple nonadiabatic model and accurately reproduces exact quantum energy levels. In addition to the semiclassical quantization condition, we also discuss chaotic dynamics involved in the classical limit of nonadiabatic dynamics.

  7. Semiclassical quantization of nonadiabatic systems with hopping periodic orbits

    Science.gov (United States)

    Fujii, Mikiya; Yamashita, Koichi

    2015-02-01

    We present a semiclassical quantization condition, i.e., quantum-classical correspondence, for steady states of nonadiabatic systems consisting of fast and slow degrees of freedom (DOFs) by extending Gutzwiller's trace formula to a nonadiabatic form. The quantum-classical correspondence indicates that a set of primitive hopping periodic orbits, which are invariant under time evolution in the phase space of the slow DOF, should be quantized. The semiclassical quantization is then applied to a simple nonadiabatic model and accurately reproduces exact quantum energy levels. In addition to the semiclassical quantization condition, we also discuss chaotic dynamics involved in the classical limit of nonadiabatic dynamics.

  8. Separable quantizations of Stäckel systems

    Science.gov (United States)

    Błaszak, Maciej; Marciniak, Krzysztof; Domański, Ziemowit

    2016-08-01

    In this article we prove that many Hamiltonian systems that cannot be separably quantized in the classical approach of Robertson and Eisenhart can be separably quantized if we extend the class of admissible quantizations through a suitable choice of Riemann space adapted to the Poisson geometry of the system. Actually, in this article we prove that for every quadratic in momenta Stäckel system (defined on 2 n dimensional Poisson manifold) for which Stäckel matrix consists of monomials in position coordinates there exist infinitely many quantizations-parametrized by n arbitrary functions-that turn this system into a quantum separable Stäckel system.

  9. Covariant geometric quantization of non-relativistic Hamiltonian mechanics

    CERN Document Server

    Giachetta, G; Sardanashvily, G

    2000-01-01

    We provide geometric quantization of the vertical cotangent bundle V^*Q equipped with the canonical Poisson structure. This is a momentum phase space of non-relativistic mechanics with the configuration bundle Q -> R. The goal is the Schrodinger representation of V^*Q. We show that this quantization is equivalent to the fibrewise quantization of symplectic fibres of V^*Q -> R, that makes the quantum algebra of non-relativistic mechanics an instantwise algebra. Quantization of the classical evolution equation defines a connection on this instantwise algebra, which provides quantum evolution in non-relativistic mechanics as a parallel transport along time.

  10. 基于准KLT域的线谱对参数压缩感知量化研究%Efficient Compressed Sensing Quantization of LSP Parameters Based on the Approximate KLT Domain

    Institute of Scientific and Technical Information of China (English)

    肖强; 陈亮; 朱涛; 黄建军

    2011-01-01

    用尽可能少的比特数实现线谱对(LSP)参数透明量化一直是语音编码领域的研究热点.该文基于压缩感知理论,研究了LSP参数在准KLT域的稀疏性,并设计了LSP参数先压缩感知再矢量量化的方案.编码端,利用压缩感知理论,在准KLT域将原始LSP参数投影到低维空间,得到低维测量值,而后采用分裂矢量量化算法对测量值进行量化;解码端,以量化后的测量值为已知条件,利用正交匹配追踪算法重构出原始LSP高维矢量,重构值作为最终量化值.实验结果表明,算法在适当的码本存储量和搜索复杂度下,达到透明量化效果所需的比特数最优时仅需5 bit/帧.%For low bit rate speech coding applications, it is very important to quantize the Line Spectrum Pair (LSP) parameters accurately using as few bits as possible without sacrificing the speech quality. In this paper, the sparsity of LSP parameters on the approximated Karhunen-Loeve Transform (KLT) domain is researched, and then an efficient LSP parameters quantization scheme is proposed based on the Compressed Sensing (CS). In the encoder, the LSP parameters extracted from consecutive speech frames are compressed by CS on the approximate KLT domain to produce a low dimensional measurement vector, the measurements are quantized using the split vector quantizer. In the decoder, according to the quantized measurements, the original LSP vector is reconstructed by the orthogonal matching pursuit method, the reconstructed LSP vector is the ultimate quantization value of the original LSP parameters. Experimental results show that the scheme can obtain transparent quality at 5 bit/frame with realistic codebook storage and search complexity.

  11. 基于N相位的60GHz无线通信波束赋形码本设计方案%N Phases Based Beamforming Codebook Design Scheme for 60 GHz Wireless Communication

    Institute of Scientific and Technical Information of China (English)

    邹卫霞; 崔志芳; 李斌; 赵心言

    2012-01-01

    提出了一种支持60 GHz毫米波通信波束赋形机制的码本设计方法.为满足低功耗需求,码本设计仅进行相位移动而未作幅度调整,其中码本矩阵采用相位间隔相同、幅度为1的N个复数权值构建.仿真结果证实,与IEEE802.15.3c码本设计相比,高阶相位码本可获得相似的波束主瓣形状,同时波束将具有更低的旁瓣电平和更高的主瓣增益.该码本方案可在多用户环境下显著抑制空间干扰,提高网络累计信道容量,且对相位误差产生的波束偏移同样具有稳健性.%A method for codebook design is proposed to support beamforming mechanism in a 60 GHz millimeter-wave wireless communication environment. The codebook is designed with only phase shifting but not any amplitude adjustment to meet the low power consumption requirement. N complex numbers of the same phase interval and amplitude of 1 are designed to generate a codebook matrix. Simulation shows that, compared with the codebook in IEEE802. 15. 3c, a similar mainlobe patterns can be obtained in the proposed high-order codebook, while the sidelobe level appears lower, and the antenna gain at the direction of main response axis is higher. Meanwhile the interference decreases obviously with an improved total channel capacity in the practice environment, and the codebook is also robust to the beam shifting deriving from phase errors.

  12. Covariance, Curved Space, Motion and Quantization

    Directory of Open Access Journals (Sweden)

    Apostol M.

    2008-01-01

    Full Text Available Weak external forces and non-inertial motion are equivalent with thefree motion in a curved space. The Hamilton-Jacobi equation is derivedfor such motion and the effects of the curvature upon the quantizationare analyzed, starting from a generalization of the Klein-Gordon equation in curved spaces. It is shown that the quantization is actually destroyed, in general, by a non-inertial motion in the presence of external forces, in the sense that such a motion may produce quantum transitions. Examples are given for a massive scalar field and for photons.

  13. Brief review on black hole loop quantization

    CERN Document Server

    Olmedo, Javier

    2016-01-01

    Here we present a review about the quantization of spherically symmetric spacetimes adopting loop quantum gravity techniques. Several models that have been studied so far share similar properties: the resolution of the classical singularity, and some of them an intrinsic discretization of the geometry. We also explain the extension to Reissner-Nordstr\\"om black holes. Besides, we review how quantum test fields on these quantum geometries allow us to study phenomena like the Casimir effect or Hawking radiation. Finally, we briefly describe a recent proposal that incorporates spherically symmetric matter, discussing its relevance for the understanding of black hole evolution.

  14. Size quantization in Cu2Se nanocrystals

    Science.gov (United States)

    Govindraju, S.; Kalenga, M. P.; Airo, M.; Moloto, M. J.; Sikhwivhilu, L. M.; Moloto, N.

    2014-12-01

    Herein we report on the synthesis of size quantized copper selenide nanocrystals via the colloidal method. Different colours of the sample were obtained at different time intervals indicative of the sizes of the nanocrystals. The absorption band edges were blue-shifted from bulk indicative of quantum confinement. This was corroborated by the TEM results that showed very small particles ranging from 2 nm to 7 nm. This work therefore shows a phenomenon readily observed in cadmium chalcogenide nanocrystals but has never been reported for copper based chalcogenides.

  15. Path Integral Quantization of Generalized Quantum Electrodynamics

    CERN Document Server

    Bufalo, Rodrigo; Zambrano, German Enrique Ramos

    2010-01-01

    It is shown in this paper a complete covariant quantization of Generalized Electrodynamics by path integral approach. To this goal we first studied the hamiltonian structure of system following Dirac's methodology, and then we follow the Faddeev-Senjanovic procedure to attain the amplitude transition. The complete propagators (Schwinger-Dyson-Fradkin equations) on correct gauge fixation and the generalized Ward-Fradkin-Takahashi identities are also obtained. Afterwards, an explicit calculation on one-loop approximation of all Green's functions and a discussion about the obtained results are presented.

  16. On field theory quantization around instantons

    CERN Document Server

    Anselmi, D

    2009-01-01

    With the perspective of looking for experimentally detectable physical applications of the so-called topological embedding, a procedure recently proposed by the author for quantizing a field theory around a non-discrete space of classical minima (instantons, for example), the physical implications are discussed in a ``theoretical'' framework, the ideas are collected in a simple logical scheme and the topological version of the Ginzburg-Landau theory of superconductivity is solved in the intermediate situation between type I and type II superconductors.

  17. Quantization of conductance minimum and index theorem

    Science.gov (United States)

    Ikegaya, Satoshi; Suzuki, Shu-Ichiro; Tanaka, Yukio; Asano, Yasuhiro

    2016-08-01

    We discuss the minimum value of the zero-bias differential conductance Gmin in a junction consisting of a normal metal and a nodal superconductor preserving time-reversal symmetry. Using the quasiclassical Green function method, we show that Gmin is quantized at (4 e2/h ) NZES in the limit of strong impurity scatterings in the normal metal at the zero temperature. The integer NZES represents the number of perfect transmission channels through the junction. An analysis of the chiral symmetry of the Hamiltonian indicates that NZES corresponds to the Atiyah-Singer index in mathematics.

  18. Black-box superconducting circuit quantization.

    Science.gov (United States)

    Nigg, Simon E; Paik, Hanhee; Vlastakis, Brian; Kirchmair, Gerhard; Shankar, S; Frunzio, Luigi; Devoret, M H; Schoelkopf, R J; Girvin, S M

    2012-06-15

    We present a semiclassical method for determining the effective low-energy quantum Hamiltonian of weakly anharmonic superconducting circuits containing mesoscopic Josephson junctions coupled to electromagnetic environments made of an arbitrary combination of distributed and lumped elements. A convenient basis, capturing the multimode physics, is given by the quantized eigenmodes of the linearized circuit and is fully determined by a classical linear response function. The method is used to calculate numerically the low-energy spectrum of a 3D transmon system, and quantitative agreement with measurements is found.

  19. Asymmetry quantization and application to human mandibles

    DEFF Research Database (Denmark)

    Glerup, Nanna; Nielsen, Mads; Sporring, Jon

    2004-01-01

    All biological objects exhibit some degree of asymmetry, but for some parts of the human body, excessive asymmetry is a sign of pathology. Hence, the problem is to draw the line between categorization of objects being too asymmetric and objects exhibiting normal asymmetry. With a measure...... for quantizing asymmetry. The methodology is based on non-rigid registration in the sense that the "size" of a diffeomorphism describes the amount of asymmetry. We will define this size in terms of the minimum biological work needed. That is, we evaluate how much work the biological system must carry out...

  20. Gravitational brainwaves, quantum fluctuations and stochastic quantization

    CERN Document Server

    Bar, D

    2007-01-01

    It is known that the biological activity of the brain involves radiation of electric waves. These waves result from ionic currents and charges traveling among the brain's neurons. But it is obvious that these ions and charges are carried by their relevant masses which should give rise, according to the gravitational theory, to extremely weak gravitational waves. We use in the following the stochastic quantization (SQ) theory to calculate the probability to find a large ensemble of brains radiating similar gravitational waves. We also use this SQ theory to derive the equilibrium state related to the known Lamb shift.

  1. Poisson sigma models and deformation quantization

    CERN Document Server

    Cattaneo, A S; Cattaneo, Alberto S.; Felder, Giovanni

    2001-01-01

    This is a review aimed at a physics audience on the relation between Poisson sigma models on surfaces with boundary and deformation quantization. These models are topological open string theories. In the classical Hamiltonian approach, we describe the reduced phase space and its structures (symplectic groupoid), explaining in particular the classical origin of the non-commutativity of the string end-point coordinates. We also review the perturbative Lagrangian approach and its connection with Kontsevich's star product. Finally we comment on the relation between the two approaches.

  2. Quantization of soluble classical constrained systems

    Energy Technology Data Exchange (ETDEWEB)

    Belhadi, Z. [Laboratoire de physique et chimie quantique, Faculté des sciences, Université Mouloud Mammeri, BP 17, 15000 Tizi Ouzou (Algeria); Laboratoire de physique théorique, Faculté des sciences exactes, Université de Bejaia, 06000 Bejaia (Algeria); Menas, F. [Laboratoire de physique et chimie quantique, Faculté des sciences, Université Mouloud Mammeri, BP 17, 15000 Tizi Ouzou (Algeria); Ecole Nationale Préparatoire aux Etudes d’ingéniorat, Laboratoire de physique, RN 5 Rouiba, Alger (Algeria); Bérard, A. [Equipe BioPhysStat, Laboratoire LCP-A2MC, ICPMB, IF CNRS No 2843, Université de Lorraine, 1 Bd Arago, 57078 Metz Cedex (France); Mohrbach, H., E-mail: herve.mohrbach@univ-lorraine.fr [Equipe BioPhysStat, Laboratoire LCP-A2MC, ICPMB, IF CNRS No 2843, Université de Lorraine, 1 Bd Arago, 57078 Metz Cedex (France)

    2014-12-15

    The derivation of the brackets among coordinates and momenta for classical constrained systems is a necessary step toward their quantization. Here we present a new approach for the determination of the classical brackets which does neither require Dirac’s formalism nor the symplectic method of Faddeev and Jackiw. This approach is based on the computation of the brackets between the constants of integration of the exact solutions of the equations of motion. From them all brackets of the dynamical variables of the system can be deduced in a straightforward way.

  3. Quantum mechanics, gravity and modified quantization relations.

    Science.gov (United States)

    Calmet, Xavier

    2015-08-06

    In this paper, we investigate a possible energy scale dependence of the quantization rules and, in particular, from a phenomenological point of view, an energy scale dependence of an effective [Formula: see text] (reduced Planck's constant). We set a bound on the deviation of the value of [Formula: see text] at the muon scale from its usual value using measurements of the anomalous magnetic moment of the muon. Assuming that inflation has taken place, we can conclude that nature is described by a quantum theory at least up to an energy scale of about 10(16) GeV.

  4. Quantization of the space of conformal blocks

    CERN Document Server

    Mukhin, E

    1997-01-01

    We consider the discrete Knizhnik-Zamolodchikov connection (qKZ) associated to $gl(N)$, defined in terms of rational R-matrices. We prove that under certain resonance conditions, the qKZ connection has a non-trivial invariant subbundle which we call the subbundle of quantized conformal blocks. The subbundle is given explicitly by algebraic equations in terms of the Yangian $Y(gl(N))$ action. The subbundle is a deformation of the subbundle of conformal blocks in CFT. The proof is based on an identity in the algebra with two generators $x,y$ and defining relation $xy=yx+yy$.

  5. Bohr-Sommerfeld Quantization of Space

    CERN Document Server

    Bianchi, Eugenio

    2012-01-01

    We introduce semiclassical methods into the study of the volume spectrum in loop gravity. The classical system behind a 4-valent spinnetwork node is a Euclidean tetrahedron. We investigate the tetrahedral volume dynamics on phase space and apply Bohr-Sommerfeld quantization to find the volume spectrum. The analysis shows a remarkable quantitative agreement with the volume spectrum computed in loop gravity. Moreover, it provides new geometrical insights into the degeneracy of this spectrum and the maximum and minimum eigenvalues of the volume on intertwiner space.

  6. Multiple Description Spherical Quantization of Sinusoidal Parameters with Repetition Coding of the Amplitudes

    DEFF Research Database (Denmark)

    Jensen, Jesper Rindom; Christensen, Mads Græsbøll; Larsen, Morten Holm

    2009-01-01

    Recently, multiple description spherical trellis-coded quantization (MDSTCQ) for quantization of sinusoidal parameters was proposed, which suffered from a suboptimal implementation. Therefore, we propose the multiple description spherical quantization with repetition coding of the amplitudes (MDS...

  7. Quasinormal Quantization in deSitter Spacetime

    CERN Document Server

    Jafferis, Daniel L; Lysov, Vyacheslav; Ng, Gim Seng; Strominger, Andrew

    2013-01-01

    A scalar field in four-dimensional deSitter spacetime (dS_4) has quasinormal modes which are singular on the past horizon of the south pole and decay exponentially towards the future. These are found to lie in two complex highest-weight representations of the dS_4 isometry group SO(4,1). The Klein-Gordon norm cannot be used for quantization of these modes because it diverges. However a modified `R-norm', which involves reflection across the equator of a spatial S^3 slice, is nonsingular. The quasinormal modes are shown to provide a complete orthogonal basis with respect to the R-norm. Adopting the associated R-adjoint effectively transforms SO(4,1) to the symmetry group SO(3,2) of a 2+1-dimensional CFT. It is further shown that the conventional Euclidean vacuum may be defined as the state annihilated by half of the quasinormal modes, and the Euclidean Green function obtained from a simple mode sum. Quasinormal quantization contrasts with some conventional approaches in that it maintains manifest dS-invariance...

  8. Can quantization improve error performance in CDMA?

    Energy Technology Data Exchange (ETDEWEB)

    Efraim, Hadar; Yacov, Nadav; Kanter, Ido [Minerva Center and Department of Physics, Bar-Ilan University, Ramat-Gan 52900 (Israel); Shental, Ori [Center for Magnetic Recording Research (CMRR), University of California, San Diego (UCSD), 9500 Gilman Drive, La Jolla, CA 92093 (United States)], E-mail: hadar.efraim@mail.biu.ac.il, E-mail: oshental@ucsd.edu, E-mail: nadav.yacov@mail.biu.ac.il, E-mail: kanter@mail.biu.ac.il

    2008-09-12

    A K-user direct-sequence spread-spectrum code-division multiple-access (CDMA) system with (q << log{sub 2}K)-bit baseband signal quantization at the demodulator is considered. It is shown that additionally quantizing the K + 1 level output signal of the CDMA modulator into q bits improves significantly the average bit-error performance in a non-negligible regime of noise variance, {sigma}{sup 2}, and user load, {beta}, under various system settings, like additive white Gaussian noise (AWGN), Rayleigh fading, single-user detection, multi-user detection, random and orthogonal spreading codes. For the case of single-user detection in random spreading AWGN-CDMA, this regime is identified explicitly as {sigma}<{gamma}(q){radical}{beta}, where {gamma}(q) is a certain pre-factor depending on q, and the associated BER improvement is derived analytically for q = 1, 2. For the other examined system settings, computer simulations are provided, corroborating this interesting behavior.

  9. Quantized conductance of a suspended graphene nanoconstriction

    CERN Document Server

    Tombros, Nikolaos; Junesch, Juliane; Guimarães, Marcos H D; Marun, Ivan J Vera; Jonkman, Harry T; van Wees, Bart J

    2011-01-01

    A yet unexplored area in graphene electronics is the field of quantum ballistic transport through graphene nanostructures. Recent developments in the preparation of high mobility graphene are expected to lead to the experimental verification and/or discovery of many new quantum mechanical effects in this field. Examples are effects due to specific graphene edges, such as spin polarization at zigzag edges of a graphene nanoribbon and the use of the valley degree of freedom in the field of graphene valleytronics8. As a first step in this direction we present the observation of quantized conductance at integer multiples of 2e^2/h at zero magnetic field and 4.2 K temperature in a high mobility suspended graphene ballistic nanoconstriction. This quantization evolves into the typical quantum Hall effect for graphene at magnetic fields above 60mT. Voltage bias spectroscopy reveals an energy spacing of 8 meV between the first two subbands. A pronounced feature at 0.6 2e^2/h present at a magnetic field as low as ~0.2T...

  10. Path Integrals and Lorentz Violation in Polymer Quantized Scalar Fields

    CERN Document Server

    Kajuri, Nirmalya

    2014-01-01

    We obtain a path integral formulation of polymer quantized scalar field theory, starting from the Hilbert Space framework. This brings the polymer quantized scalar field theory under the ambit of Feynman diagrammatic techniques. The path integral formulation also shows that Lorentz invariance is lost for the Klein-Gordon field.

  11. From topological field theory to deformation quantization and reduction

    CERN Document Server

    Cattaneo, Alberto S

    2016-01-01

    This note describes the functional-integral quantization of two-dimensional topological field theories together with applications to problems in deformation quantization of Poisson manifolds and reduction of certain submanifolds. A brief introduction to smooth graded manifolds and to the Batalin-Vilkovisky formalism is included.

  12. Faddeev–Jackiw quantization of non-autonomous singular systems

    Energy Technology Data Exchange (ETDEWEB)

    Belhadi, Zahir [Laboratoire de physique théorique, Faculté des sciences exactes, Université de Bejaia, 06000 Bejaia (Algeria); Equipe BioPhyStat, ICPMB, IF CNRS N 2843, Université de Lorraine, 57070 Metz Cedex (France); Bérard, Alain [Equipe BioPhyStat, ICPMB, IF CNRS N 2843, Université de Lorraine, 57070 Metz Cedex (France); Mohrbach, Hervé, E-mail: herve.mohrbach@univ-lorraine.fr [Equipe BioPhyStat, ICPMB, IF CNRS N 2843, Université de Lorraine, 57070 Metz Cedex (France)

    2016-10-07

    We extend the quantization à la Faddeev–Jackiw for non-autonomous singular systems. This leads to a generalization of the Schrödinger equation for those systems. The method is exemplified by the quantization of the damped harmonic oscillator and the relativistic particle in an external electromagnetic field.

  13. A family of quantization based piecewise linear filter networks

    DEFF Research Database (Denmark)

    Sørensen, John Aasted

    1992-01-01

    A family of quantization-based piecewise linear filter networks is proposed. For stationary signals, a filter network from this family is a generalization of the classical Wiener filter with an input signal and a desired response. The construction of the filter network is based on quantization of...

  14. Parameters Design for Logarithmic Quantizer Based on Zoom Strategy

    Directory of Open Access Journals (Sweden)

    Jingjing Yan

    2017-01-01

    Full Text Available This paper is concerned with the problem of designing suitable parameters for logarithmic quantizer such that the closed-loop system is asymptotic convergent. Based on zoom strategy, we propose two methods for quantizer parameters design, under which it ensures that the state of the closed-loop system can load in the invariant sets after some certain moments. Then we obtain that the quantizer is unsaturated, and thus the quantization errors are bounded under the time-varying logarithm quantization strategy. On that basis, we obtain that the closed-loop system is asymptotic convergent. A benchmark example is given to show the usefulness of the proposed methods, and the comparison results are illustrated.

  15. Fractional quantization of charge and spin in topological quantum pumps

    Science.gov (United States)

    Marra, Pasquale; Citro, Roberta

    2017-07-01

    Topological quantum pumps are topologically equivalent to the quantum Hall state: In these systems, the charge pumped during each pumping cycle is quantized and coincides with the Chern invariant. However, differently from quantum Hall insulators, quantum pumps can exhibit novel phenomena such as the fractional quantization of the charge transport, as a consequence of their distinctive symmetries in parameter space. Here, we report the analogous fractional quantization of the spin transport in a topological spin pump realized in a one-dimensional lattice via a periodically modulated Zeeman field. In the proposed model, which is a spinfull generalization of the Harper-Hofstadter model, the amount of spin current pumped during well-defined fractions of the pumping cycle is quantized as fractions of the spin Chern number. This fractional quantization of spin is topological, and is a direct consequence of the additional symmetries ensuing from the commensuration of the periodic field with the underlying lattice.

  16. Log-Polar Quantizer with the Embedded G.711 Codec

    Directory of Open Access Journals (Sweden)

    Z. H. Peric

    2010-12-01

    Full Text Available In this paper a new two-dimensional vector quantizer for memoryless Gaussian source, realized in polar coordinates, is proposed. The G.711 codec is embedded in our vector quantizer, and therefore our vector quantizer is compatible with the G.711 codec. It is simple for realization and it has much better performances, compared to the G.711 codec, such as much higher SQNR (signal-to-quantization noise ratio for the same bit-rate, or bit-rate decrease for the same SQNR. The G.711 codec is widely used in many systems, especially in PSTN (public switched telephone network. Due to compatibility with the G.711 standard, our vector quantizer can be realized with simple software modification of the existing the G.711 codec, and therefore it can be very easily implemented in PSTN and other systems. So, small investments are needed for wide implementation of our model, but significant improvement of performances can be obtained.

  17. Lattice radial quantization: 3D Ising

    Energy Technology Data Exchange (ETDEWEB)

    Brower, R.C., E-mail: brower@bu.edu [Department of Physics, Boston University, Boston, MA 02215 (United States); Fleming, G.T., E-mail: george.fleming@yale.edu [Department of Physics, Yale University, New Haven, CT 06520 (United States); Neuberger, H., E-mail: neuberg@physics.rutgers.edu [Department of Physics and Astronomy, Rutgers University, Piscataway, NJ 08855 (United States)

    2013-04-25

    Lattice radial quantization is introduced as a nonperturbative method intended to numerically solve Euclidean conformal field theories that can be realized as fixed points of known Lagrangians. As an example, we employ a lattice shaped as a cylinder with a 2D Icosahedral cross-section to discretize dilatations in the 3D Ising model. Using the integer spacing of the anomalous dimensions of the first two descendants (l=1,2), we obtain an estimate for η=0.034(10). We also observed small deviations from integer spacing for the 3rd descendant, which suggests that a further improvement of our radial lattice action will be required to guarantee conformal symmetry at the Wilson–Fisher fixed point in the continuum limit.

  18. Phase-space quantization of field theory.

    Energy Technology Data Exchange (ETDEWEB)

    Curtright, T.; Zachos, C.

    1999-04-20

    In this lecture, a limited introduction of gauge invariance in phase-space is provided, predicated on canonical transformations in quantum phase-space. Exact characteristic trajectories are also specified for the time-propagating Wigner phase-space distribution function: they are especially simple--indeed, classical--for the quantized simple harmonic oscillator. This serves as the underpinning of the field theoretic Wigner functional formulation introduced. Scalar field theory is thus reformulated in terms of distributions in field phase-space. This is a pedagogical selection from work published and reported at the Yukawa Institute Workshop ''Gauge Theory and Integrable Models'', 26-29 January, 1999.

  19. Covariant Quantization of CPT-violating Photons

    CERN Document Server

    Colladay, D; Noordmans, J P; Potting, R

    2016-01-01

    We perform the covariant canonical quantization of the CPT- and Lorentz-symmetry-violating photon sector of the minimal Standard-Model Extension, which contains a general (timelike, lightlike, or spacelike) fixed background tensor $k_{AF}^\\mu$. Well-known stability issues, arising from complex-valued energy states, are solved by introducing a small photon mass, orders of magnitude below current experimental bounds. We explicitly construct a covariant basis of polarization vectors, in which the photon field can be expanded. We proceed to derive the Feynman propagator and show that the theory is microcausal. Despite the occurrence of negative energies and vacuum-Cherenkov radiation, we do not find any runaway stability issues, because the energy remains bounded from below. An important observation is that the ordering of the roots of the dispersion relations is the same in any observer frame, which allows for a frame-independent condition that selects the correct branch of the dispersion relation. This turns ou...

  20. Quantization of rotating linear dilaton black holes

    Energy Technology Data Exchange (ETDEWEB)

    Sakalli, I. [Eastern Mediterranean University, Department of Physics, Mersin 10 (Turkey)

    2015-04-15

    In this paper, we focus on the quantization of four-dimensional rotating linear dilaton black hole (RLDBH) spacetime describing an action, which emerges in the Einstein-Maxwell-dilaton-axion (EMDA) theory. RLDBH spacetime has a non-asymptotically flat geometry. When the rotation parameter ''a'' vanishes, the spacetime reduces to its static form, the so-called linear dilaton black hole (LDBH) metric. Under scalar perturbations, we show that the radial equation reduces to a hypergeometric differential equation. Using the boundary conditions of the quasinormal modes (QNMs), we compute the associated complex frequencies of the QNMs. In a particular case, QNMs are applied in the rotational adiabatic invariant quantity, and we obtain the quantum entropy/area spectra of the RLDBH. Both spectra are found to be discrete and equidistant, and independent of the a-parameter despite the modulation of QNMs by this parameter. (orig.)

  1. A New Algorithm to Smooth Quantization Errors

    CERN Document Server

    Paul, A; Paul, Ayan

    2005-01-01

    We have devised a simple numerical technique to treat rugged data points that arise due to the insufficient gain setting error (or quantization error) of a digital instrument. This is a very wide spread problem that all experimentalists encounter some time or the other and they are forced to deal with it by suitable adjustments of instrument gains and other relevant parameters. But mostly this entails one to repeat the experiment,this may be inconvenient at the least. Here we prescribe a method that would actually attempt to smoothen the data set that is already so obtained. Our method is based on an entirely different algorithm that is not available anywhere else. This method mimics what one would do by intuitive visual inspection and not like the arcane digital filtering, spline fitting etc. that is available in the market. Nor does it depend on any instrumental parameter tweaking. This makes the program totally general purpose and also intellectually more satisfying.

  2. Classical covariant Poisson structures and Deformation Quantization

    CERN Document Server

    Berra-Montiel, Jasel; Palacios-García, César D

    2014-01-01

    Starting with the well-defined product of quantum fields at two spacetime points, we explore an associated Poisson structure for classical field theories within the deformation quantization formalism. We realize that the induced star-product is naturally related to the standard Moyal product through the causal Green functions connecting points in the space of classical solutions to the equations of motion. Our results resemble the Peierls-DeWitt bracket analyzed in the multisymplectic context. Once our star-product is defined we are able to apply the Wigner-Weyl map in order to introduce a generalized version of Wick's theorem. Finally, we include a couple of examples to explicitly test our method: the real scalar field and the bosonic string. For both models we have encountered generalizations of the creation/annihilation relations, and also a generalization of the Virasoro algebra in the bosonic string case.

  3. Learning Vector Quantization for Classifying Astronomical Objects

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    The sizes of astronomical surveys in different wavebands are increas-ing rapidly. Therefore, automatic classification of objects is becoming ever moreimportant. We explore the performance of learning vector quantization (LVQ) inclassifying multi-wavelength data. Our analysis concentrates on separating activesources from non-active ones. Different classes of X-ray emitters populate distinctregions of a multidimensional parameter space. In order to explore the distributionof various objects in a multidimensional parameter space, we positionally cross-correlate the data of quasars, BL Lacs, active galaxies, stars and normal galaxiesin the optical, X-ray and infrared bands. We then apply LVQ to classify them withthe obtained data. Our results show that LVQ is an effective method for separatingAGNs from stars and normal galaxies with multi-wavelength data.

  4. Boundary Liouville Theory: Hamiltonian Description and Quantization

    Directory of Open Access Journals (Sweden)

    Harald Dorn

    2007-01-01

    Full Text Available The paper is devoted to the Hamiltonian treatment of classical and quantum properties of Liouville field theory on a timelike strip in 2d Minkowski space. We give a complete description of classical solutions regular in the interior of the strip and obeying constant conformally invariant conditions on both boundaries. Depending on the values of the two boundary parameters these solutions may have different monodromy properties and are related to bound or scattering states. By Bohr-Sommerfeld quantization we find the quasiclassical discrete energy spectrum for the bound states in agreement with the corresponding limit of spectral data obtained previously by conformal bootstrap methods in Euclidean space. The full quantum version of the special vertex operator $e^varphi$ in terms of free field exponentials is constructed in the hyperbolic sector.

  5. Quantizing polaritons in inhomogeneous dissipative systems

    Science.gov (United States)

    Drezet, Aurélien

    2017-02-01

    In this article we provide a general analysis of canonical quantization for polaritons in dispersive and dissipative electromagnetic inhomogeneous media. We compare several approaches based either on the Huttner-Barnett model [B. Huttner and S. M. Barnett, Phys. Rev. A 46, 4306 (1992), 10.1103/PhysRevA.46.4306] or the Green function, Langevin-noise method [T. Gruner and D.-G. Welsch, Phys. Rev. A 53, 1818 (1996), 10.1103/PhysRevA.53.1818] which includes only material oscillators as fundamental variables. We show that in order to preserve unitarity, causality, and time symmetry, one must necessarily include with an equal footing both electromagnetic modes and material fluctuations in the evolution equations. This becomes particularly relevant for all nanophotonics and plasmonics problems involving spatially localized antennas or devices.

  6. Auditory—Spectrum Quantization Based Speech Recognition

    Institute of Scientific and Technical Information of China (English)

    WuYuanqing; HaoJie; 等

    1997-01-01

    Based on the analysis of the physiological and psychological characteristics of human auditory system[1],we can classify human auditory process into two hearing modes:active one and passive one.A novel approach of robust speech recognition,Auditory-spectrum Quantization Based Speech Recognition(AQBSR),is proposed.In this method,we intend to simulate human active hearing mode and locate the effective areas of speech signals in temporal domain and in frequency domain.Adaptive filter banks are used in place of fixed-band filters to extract feature parameters.The effective speech components and their corresponding frequency areas of each word in the vocabulary can be found out during training.In recognition stage,comparison between the unknown sound and the current template is maintained only in the effective areas of the template word.The control experiments show that the AQ BSR method is more robust than traditional systems.

  7. Modified 8×8 quantization table and Huffman encoding steganography

    Science.gov (United States)

    Guo, Yongning; Sun, Shuliang

    2014-10-01

    A new secure steganography, which is based on Huffman encoding and modified quantized discrete cosine transform (DCT) coefficients, is provided in this paper. Firstly, the cover image is segmented into 8×8 blocks and modified DCT transformation is applied on each block. Huffman encoding is applied to code the secret image before embedding. DCT coefficients are quantized by modified quantization table. Inverse DCT(IDCT) is conducted on each block. All the blocks are combined together and the steg image is finally achieved. The experiment shows that the proposed method is better than DCT and Mahender Singh's in PSNR and Capacity.

  8. Lattice Vector Quantization Applied to Speech and Audio Coding

    Institute of Scientific and Technical Information of China (English)

    Minjie Xie

    2012-01-01

    Lattice vector quantization (LVQ) has been used for real-time speech and audio coding systems. Compared with conventional vector quantization, LVQ has two main advantages: It has a simple and fast encoding process, and it significantly reduces the amount of memory required. Therefore, LVQ is suitable for use in low-complexity speech and audio coding. In this paper, we describe the basic concepts of LVQ and its advantages over conventional vector quantization. We also describe some LVQ techniques that have been used in speech and audio coding standards of international standards developing organizations (SDOs).

  9. Radial action-phase quantization in Bose-Einstein condensates

    Energy Technology Data Exchange (ETDEWEB)

    Reinisch, Gilbert [Departement Cassiopee, Observatoire de la Cote d' Azur, BP 4229, 06304-Nice cedex 4 (France)], E-mail: gilbert@oca.eu

    2008-02-04

    The 2D radial stationary nonlinear Schroedinger equation yields a new action-phase quantization of energy, in contrast with the linear case where the energy levels are degenerated with respect to the Ermakov constant. Characteristic values of radial energy quantization are given in the Gross-Pitaevskii mean-field description for the main vortex-nucleation experiments performed in rotating Bose-Einstein condensates. Finally, the link with Einstein's conjecture about non-quantizability of quasiperiodic orbits on a 2D torus is pointed out.

  10. A Quantized Analog Delay for an ir-UWB Quadrature Downconversion Autocorrelation Receiver

    NARCIS (Netherlands)

    Bagga, S.; Zhang, L.; Serdijn, W.A.; Long, J.R.; Busking, E.B.

    2005-01-01

    A quantized analog delay is designed as a requirement for the autocorrelation function in the quadrature downconversion autocorrelation receiver (QDAR). The quantized analog delay is comprised of a quantizer, multiple binary delay lines and an adder circuit. Being the foremost element, the quantizer

  11. Algebra Automorphisms of Quantized Enveloping Algebras Uq(■)

    Institute of Scientific and Technical Information of China (English)

    查建国

    1994-01-01

    The algebra automorphisms of the quantized enveloping algebra Uq(g) are discussed, where q is generic. To some extent, all quantum deformations of automorphisms of the simple Lie algebra g have been determined.

  12. A physically motivated quantization of the electromagnetic field

    Science.gov (United States)

    Bennett, Robert; Barlow, Thomas M.; Beige, Almut

    2016-01-01

    The notion that the electromagnetic field is quantized is usually inferred from observations such as the photoelectric effect and the black-body spectrum. However accounts of the quantization of this field are usually mathematically motivated and begin by introducing a vector potential, followed by the imposition of a gauge that allows the manipulation of the solutions of Maxwell’s equations into a form that is amenable for the machinery of canonical quantization. By contrast, here we quantize the electromagnetic field in a less mathematically and more physically motivated way. Starting from a direct description of what one sees in experiments, we show that the usual expressions of the electric and magnetic field observables follow from Heisenberg’s equation of motion. In our treatment, there is no need to invoke the vector potential in a specific gauge and we avoid the commonly used notion of a fictitious cavity that applies boundary conditions to the field.

  13. Precise quantization of anomalous Hall effect near zero magnetic field

    Science.gov (United States)

    Bestwick, Andrew; Fox, Eli; Kou, Xufeng; Pan, Lei; Wang, Kang; Goldhaber-Gordon, David

    2015-03-01

    The quantum anomalous Hall effect (QAHE) has recently been of great interest due to its recent experimental realization in thin films of Cr-doped (Bi, Sb)2Te3, a ferromagnetic 3D topological insulator. The presence of ferromagnetic exchange breaks time-reversal symmetry, opening a gap in the surface states, but gives rise to dissipationless chiral conduction at the edge of a magnetized film. Ideally, this leads to vanishing longitudinal resistance and Hall resistance quantized to h /e2 , where h is Planck's constant and e is the electron charge, but perfect quantization has so far proved elusive. Here, we study the QAHE in the limit of zero applied magnetic field, and measure Hall resistance quantized to within one part per 10,000. Deviation from quantization is due primarily to thermally activated carriers, which can be nearly eliminated through adiabatic demagnetization cooling. This result demonstrates an important step toward dissipationless electron transport in technologically relevant conditions.

  14. Pluto Moons exhibit Orbital Angular Momentum Quantization per Mass

    Directory of Open Access Journals (Sweden)

    Potter F.

    2012-10-01

    Full Text Available The Pluto satellite system of the planet plus five moons is shown to obey the quan- tum celestial mechanics (QCM angular momentum per mass quantization condition predicted for any gravitationally bound system.

  15. Polymer-Fourier quantization of the scalar field revisited

    Science.gov (United States)

    Garcia-Chung, Angel; Vergara, J. David

    2016-10-01

    The polymer quantization of the Fourier modes of the real scalar field is studied within algebraic scheme. We replace the positive linear functional of the standard Poincaré invariant quantization by a singular one. This singular positive linear functional is constructed as mimicking the singular limit of the complex structure of the Poincaré invariant Fock quantization. The resulting symmetry group of such polymer quantization is the subgroup SDiff(ℝ4) which is a subgroup of Diff(ℝ4) formed by spatial volume preserving diffeomorphisms. In consequence, this yields an entirely different irreducible representation of the canonical commutation relations, nonunitary equivalent to the standard Fock representation. We also compared the Poincaré invariant Fock vacuum with the polymer Fourier vacuum.

  16. Polymer-Fourier quantization of the scalar field revisited

    CERN Document Server

    Garcia-Chung, Angel

    2016-01-01

    The Polymer Quantization of the Fourier modes of the real scalar field is studied within algebraic scheme. We replace the positive linear functional of the standard Poincar\\'e invariant quantization by a singular one. This singular positive linear functional is constructed as mimicking the singular limit of the complex structure of the Poincar\\'e invariant Fock quantization. The resulting symmetry group of such Polymer Quantization is the subgroup $\\mbox{SDiff}(\\mathbb{R}^4)$ which is a subgroup of $\\mbox{Diff}(\\mathbb{R}^4)$ formed by spatial volume preserving diffeomorphisms. In consequence, this yields an entirely different irreducible representation of the Canonical Commutation Relations, non-unitary equivalent to the standard Fock representation. We also compared the Poincar\\'e invariant Fock vacuum with the Polymer Fourier vacuum.

  17. the influence of quantization process on the performance of global ...

    African Journals Online (AJOL)

    Mgina

    performance can be influenced by the nature of the quantization process required a priori, .... Block diagram showing the measurement system used in this work ..... sensor unit is mounted on a vertical pipe with the flow traveling upward.

  18. Remarks on the geometric quantization of Landau levels

    Science.gov (United States)

    Galasso, Andrea; Spera, Mauro

    2016-08-01

    In this note, we resume the geometric quantization approach to the motion of a charged particle on a plane, subject to a constant magnetic field perpendicular to the latter, by showing directly that it gives rise to a completely integrable system to which we may apply holomorphic geometric quantization. In addition, we present a variant employing a suitable vertical polarization and we also make contact with Bott’s quantization, enforcing the property “quantization commutes with reduction”, which is known to hold under quite general conditions. We also provide an interpretation of translational symmetry breaking in terms of coherent states and index theory. Finally, we give a representation theoretic description of the lowest Landau level via the use of an S1-equivariant Dirac operator.

  19. Differentiable Kernels in Generalized Matrix Learning Vector Quantization

    NARCIS (Netherlands)

    Kästner, M.; Nebel, D.; Riedel, M.; Biehl, M.; Villmann, T.

    2013-01-01

    In the present paper we investigate the application of differentiable kernel for generalized matrix learning vector quantization as an alternative kernel-based classifier, which additionally provides classification dependent data visualization. We show that the concept of differentiable kernels allo

  20. Path integral quantization of the relativistic Hopfield model

    CERN Document Server

    Belgiorno, F; Piazza, F Dalla; Doronzo, M

    2016-01-01

    The path integral quantization method is applied to a relativistically covariant version of the Hopfield model, which represents a very interesting mesoscopic framework for the description of the interaction between quantum light and dielectric quantum matter, with particular reference to the context of analogue gravity. In order to take into account the constraints occurring in the model, we adopt the Faddeev-Jackiw approach to constrained quantization in the path integral formalism. In particular we demonstrate that the propagator obtained with the Faddeev-Jackiw approach is equivalent to the one which, in the framework of Dirac canonical quantization for constrained systems, can be directly computed as the vacuum expectation value of the time ordered product of the fields. Our analysis also provides an explicit example of quantization of the electromagnetic field in a covariant gauge and coupled with the polarization field, which is a novel contribution to the literature on the Faddeev-Jackiw procedure.

  1. Video coding scheme using DCT-pyramid vector quantization.

    Science.gov (United States)

    Dalessandro, P; Lancini, R

    1995-01-01

    A new and effective video coding scheme for contribution quality is proposed. The CMTT/2, a joint committee of CCIR and CCITT, has proposed a video coding scheme (already approved at European level by ETS) working at 34-45 Mbit/s. Basically this proposal includes a DCT transform for spatial correlation removal and motion compensation for temporal correlation removal. The individual transform coefficients are then scalar quantized with a non uniform bit assignment. Starting from the CMTT/2 proposal, the study presents a new video coding scheme designed using a vector quantizer solution instead of the scalar one. Specifically, the pyramid vector quantization (PVQ) has been chosen as the vector quantization method as it is able to reduce the DCT coefficients Laplacian distribution. Simulation results show that the proposed video coding scheme gives the same contribution quality at 22 Mbit/s as the one obtained with the CMTT/2 proposal at 45 Mbit/s.

  2. Minimum uncertainty and squeezing in diffusion processes and stochastic quantization

    Science.gov (United States)

    Demartino, S.; Desiena, S.; Illuminati, Fabrizo; Vitiello, Giuseppe

    1994-01-01

    We show that uncertainty relations, as well as minimum uncertainty coherent and squeezed states, are structural properties for diffusion processes. Through Nelson stochastic quantization we derive the stochastic image of the quantum mechanical coherent and squeezed states.

  3. The Effect of Quantization Error on Display Color Gamut Transformation

    Institute of Scientific and Technical Information of China (English)

    Yu Chen; Tiefu Ding

    2003-01-01

    Researchers and designers who work with color displays often transform color gamut between two different display devices. This paper demonstrates the effect of quantization error on the transformation based on analyzing the color gamut deviation profoundly.

  4. Quantization of Two-Dimensional Gravity with Dynamical Torsion

    CERN Document Server

    Lavrov, P M

    1999-01-01

    We consider two-dimensional gravity with dynamical torsion in the Batalin - Vilkovisky and Batalin - Lavrov - Tyutin formalisms of gauge theories quantization as well as in the background field method.

  5. Quantization of systems with $OSp(2|2)$ symmetry

    CERN Document Server

    Kawamura, Yoshiharu

    2015-01-01

    We study the quantization of systems with $OSp(2|2)$ symmetry. Systems contain ordinary fields and their counterparts with different statistics. The unitarity of systems holds by imposing subsidiary conditions on states.

  6. A family quantization formula for symplectic manifolds with boundary

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    his paper generalizes the family quantization formula of Zh angto the case of manifolds with boundary. As an application, Tian-Zhang's ana lytic version of the Guillemin-Kalkman-Martin residue formula is generalized to the family case.

  7. Gupta-Bleuler Photon Quantization in the SME

    CERN Document Server

    Colladay, Don; Potting, Robertus

    2014-01-01

    Photon quantization is implemented in the standard model extension (SME) using the Gupta-Bleuler method and BRST concepts. The quantization prescription applies to both the birefringent and non-birefringent CPT-even couplings. A curious incompatibility is found between the presence of the Lorentz-violating terms and the existence of a nontrivial conjugate momentum $\\Pi^0$ yielding problems with covariant quantization procedure. Introduction of a mass regulator term can avoid the vanishing of $\\Pi^0$ and allows for the implementation of a covariant quantization procedure. Field-theoretic calculations involving the SME photons can then be performed using the mass regulator, similar to the conventional procedure used in electrodynamics for infrared-divergence regulation.

  8. Inelastic scattering of xenon atoms by quantized vortices in superfluids

    CERN Document Server

    Pshenichnyuk, I A

    2016-01-01

    We study inelastic interactions of particles with quantized vortices in superfluids by using a semi-classical matter wave theory that is analogous to the Landau two-fluid equations, but allows for the vortex dynamics. The research is motivated by recent experiments on xenon doped helium nanodroplets that show clustering of the impurities along the vortex cores. We numerically simulate the dynamics of trapping and interactions of xenon atoms by quantized vortices in superfluid helium and the obtained results can be extended to scattering of other impurities by quantized vortices. Different energies and impact parameters of incident particles are considered. We show that inelastic scattering is closely linked to the generation of Kelvin waves along a quantized vortex during the interaction even if there is no capture. The capture criterion of an impurity is formulated in terms of the binding energy.

  9. Rate-of-change limiter for quantized signals

    Science.gov (United States)

    Streuding, G. C.

    1977-01-01

    Analog circuit is employed to smooth change between levels of quantized voltage signal without adversely affecting its fidelity. Circuit is applicable to units requiring interface between digital and analog systems such as automated manufacturing systems or industrial robots.

  10. Universal Features of Quantized Thermal Conductance of Carbon Nanotubes

    OpenAIRE

    Yamamoto, Takahiro; Watanabe, Satoshi; Watanabe, Kazuyuki

    2003-01-01

    The universal features of quantized thermal conductance of carbon nanotubes (CNTs) are revealed through theoretical analysis based on the Landauer theory of heat transport. The phonon-derived thermal conductance of semiconducting CNTs exhibits a universal quantization in the low temperature limit, independent of the radius or atomic geometry. The temperature dependence follows a single curve given in terms of temperature scaled by the phonon energy gap. The thermal conductance of metallic CNT...

  11. An Analysis of Perturbed Quantization Steganography in the Spatial Domain

    Science.gov (United States)

    2005-03-01

    steganography is also common with audio [KaP00]. Figure 1 depicts this form of steganography . Figure 1. Least Significant Bit Substitution 6...QUANTIZATION STEGANOGRAPHY IN THE SPATIAL DOMAIN THESIS Matthew D. Spisak AFIT/GIA/ENG/05-04DEPARTMENT OF THE AIR FORCE AIR UNIVERSITY ORCE...ANALYSIS OF PERTURBED QUANTIZATION STEGANOGRAPHY IN THE SPATIAL DOMAIN THESIS Presented to the Faculty Department of Electrical and

  12. Electronic Wave Packet in a Quantized Electromagnetic Field

    Institute of Scientific and Technical Information of China (English)

    程太旺; 薛艳丽; 李晓峰; 吴令安; 傅盘铭

    2002-01-01

    We study a non-stationary electronic wave packet in a quantized electromagnetic field. Generally, the electron and field become entangled as the electronic wave packet evolves. Here we find that, when the initial photon state is a coherent one, the wavefunction of the system can be factorized if we neglect the transferred photon number. In this case, the quantized-field calculation is equivalent to the semi-classical calculation.

  13. Noether Symmetries Quantization and Superintegrability of Biological Models

    Directory of Open Access Journals (Sweden)

    Maria Clara Nucci

    2016-12-01

    Full Text Available It is shown that quantization and superintegrability are not concepts that are inherent to classical Physics alone. Indeed, one may quantize and also detect superintegrability of biological models by means of Noether symmetries. We exemplify the method by using a mathematical model that was proposed by Basener and Ross (2005, and that describes the dynamics of growth and sudden decrease in the population of Easter Island.

  14. Representation Theory of Quantized Enveloping Algebras with Interpolating Real Structure

    Directory of Open Access Journals (Sweden)

    Kenny De Commer

    2013-12-01

    Full Text Available Let g be a compact simple Lie algebra. We modify the quantized enveloping ∗-algebra associated to g by a real-valued character on the positive part of the root lattice. We study the ensuing Verma module theory, and the associated quotients of these modified quantized enveloping ∗-algebras. Restricting to the locally finite part by means of a natural adjoint action, we obtain in particular examples of quantum homogeneous spaces in the operator algebraic setting.

  15. Rarita-Schwinger Quantum Free Field Via Deformation Quantization

    CERN Document Server

    Perez, B Carballo

    2011-01-01

    Rarita-Schwinger (RS) quantum free field is reexamined in the context of deformation quantization. It is found out that the subsidiary condition does not introduce any change either in the Wigner function or in other aspects of the deformation quantization formalism, in relation to the Dirac field case. This happens because the vector structure of the RS field imposes constraints on the space of wave function solutions and not on the operator structure. The RS propagator was also calculated within this formalism.

  16. Quantization of edge currents along magnetic barriers and magnetic guides

    CERN Document Server

    Dombrowski, N; Raikov, G D

    2010-01-01

    We investigate the edge conductance of particles submitted to an Iwatsuka magnetic field, playing the role of a purely magnetic barrier. We also consider magnetic guides generated by generalized Iwatsuka potentials. In both cases we prove quantization of the edge conductance. Next, we consider magnetic perturbations of such magnetic barriers or guides, and prove stability of the quantized value of the edge conductance. Further, we establish a sum rule for edge conductances. Regularization within the context of disordered systems is discussed as well.

  17. Light-front Quantized Field Theory Some New Results

    CERN Document Server

    Srivastava, P P

    1999-01-01

    A review is made on some recent studies which support the point of view that the relativistic field theory quantized on the light-front (LF) is more transparent compared to the conventional equal-time one. The discussion may be of relevance in the context of the quantization of gravitation theory. The LF quantization is argued to be equally appropriate as the conventional equal-time one. The description on the LF of the spontaneous symmetry breaking and the (tree level) Higgs mechanism, the emergence of the $\\theta$-vacua in the Schwinger model, the absence of such vacua in the Chiral SM, the BRS-BFT quantization of the latter on the LF are among the topics discussed. Comments on the irrelevance, in the quantized theory, of the fact that the hyperplanes $x^{\\pm}=0$ constitute characteristic surfaces of the hyperbolic partial differential equation are also made. The LF theory quantized on, say, the $x^{+}=const.$ hyperplanes seems to already contain in it the information on the equal-$x^{-}$ commutators as wel...

  18. Dynamics of Quantized Vortices Before Reconnection

    Science.gov (United States)

    Andryushchenko, V. A.; Kondaurova, L. P.; Nemirovskii, S. K.

    2016-12-01

    The main goal of this paper is to investigate numerically the dynamics of quantized vortex loops, just before the reconnection at finite temperature, when mutual friction essentially changes the evolution of lines. Modeling is performed on the base of vortex filament method using the full Biot-Savart equation. It was discovered that the initial position of vortices and the temperature strongly affect the dependence on time of the minimum distance δ (t) between tips of two vortex loops. In particular, in some cases, the shrinking and collapse of vortex loops due to mutual friction occur earlier than the reconnection, thereby canceling the latter. However, this relationship takes a universal square-root form δ ( t) =√{( κ /2π ) ( t_{*}-t) } at distances smaller than the distances, satisfying the Schwarz reconnection criterion, when the nonlocal contribution to the Biot-Savart equation becomes about equal to the local contribution. In the "universal" stage, the nearest parts of vortices form a pyramid-like structure with angles which neither depend on the initial configuration nor on temperature.

  19. Wheeler-DeWitt quantization and singularities

    CERN Document Server

    Falciano, Felipe Tovar; Struyve, Ward

    2015-01-01

    We consider a Bohmian approach to the Wheeler-DeWitt quantization of the Friedmann-Lemaitre-Robertson-Walker model and investigate the question whether or not there are singularities, in the sense that the universe reaches zero volume. We find that for generic wave functions (i.e., non-classical wave functions), there is a non-zero probability for a trajectory to be non-singular. This should be contrasted to the consistent histories approach for which it was recently shown by Craig and Singh that there is always a singularity. This result illustrates that the question of singularities depends much on which version of quantum theory one adopts. This was already pointed out by Pinto-Neto et al., albeit with a different Bohmian approach. Our current Bohmian approach agrees with the consistent histories approach by Craig and Singh for single-time histories, unlike the one studied earlier by Pinto-Neto et al. Although the trajectories are usually different in the two Bohmian approach, their qualitative behavior is...

  20. Causal Poisson bracket via deformation quantization

    Science.gov (United States)

    Berra-Montiel, Jasel; Molgado, Alberto; Palacios-García, César D.

    2016-06-01

    Starting with the well-defined product of quantum fields at two spacetime points, we explore an associated Poisson structure for classical field theories within the deformation quantization formalism. We realize that the induced star-product is naturally related to the standard Moyal product through an appropriate causal Green’s functions connecting points in the space of classical solutions to the equations of motion. Our results resemble the Peierls-DeWitt bracket that has been analyzed in the multisymplectic context. Once our star-product is defined, we are able to apply the Wigner-Weyl map in order to introduce a generalized version of Wick’s theorem. Finally, we include some examples to explicitly test our method: the real scalar field, the bosonic string and a physically motivated nonlinear particle model. For the field theoretic models, we have encountered causal generalizations of the creation/annihilation relations, and also a causal generalization of the Virasoro algebra for the bosonic string. For the nonlinear particle case, we use the approximate solution in terms of the Green’s function, in order to construct a well-behaved causal bracket.

  1. Casimir-Polder interaction in second quantization

    Energy Technology Data Exchange (ETDEWEB)

    Schiefele, Juergen

    2011-03-21

    The Casimir-Polder interaction between a single neutral atom and a nearby surface, arising from the (quantum and thermal) fluctuations of the electromagnetic field, is a cornerstone of cavity quantum electrodynamics (cQED), and theoretically well established. Recently, Bose-Einstein condensates (BECs) of ultracold atoms have been used to test the predictions of cQED. The purpose of the present thesis is to upgrade single-atom cQED with the many-body theory needed to describe trapped atomic BECs. Tools and methods are developed in a second-quantized picture that treats atom and photon fields on the same footing. We formulate a diagrammatic expansion using correlation functions for both the electromagnetic field and the atomic system. The formalism is applied to investigate, for BECs trapped near surfaces, dispersion interactions of the van der Waals-Casimir-Polder type, and the Bosonic stimulation in spontaneous decay of excited atomic states. We also discuss a phononic Casimir effect, which arises from the quantum fluctuations in an interacting BEC. (orig.)

  2. Path integral quantization of parametrised field theory

    CERN Document Server

    Varadarajan, M

    2004-01-01

    Free scalar field theory on a flat spacetime can be cast into a generally covariant form known as parametrised field theory in which the action is a functional of the scalar field as well as the embedding variables which describe arbitrary, in general curved, foliations of the flat spacetime. We construct the path integral quantization of parametrised field theory in order to analyse issues at the interface of quantum field theory and general covariance in a path integral context. We show that the measure in the Lorentzian path integral is non-trivial and is the analog of the Fradkin- Vilkovisky measure for quantum gravity. We construct Euclidean functional integrals in the generally covariant setting of parametrised field theory using key ideas of Schleich and show that our constructions imply the existence of non-standard `Wick rotations' of the standard free scalar field 2 point function. We develop a framework to study the problem of time through computations of scalar field 2 point functions. We illustra...

  3. Interactions between unidirectional quantized vortex rings

    CERN Document Server

    Zhu, T; Brown, R A; Walmsley, P M; Golov, A I

    2016-01-01

    We have used the vortex filament method to numerically investigate the interactions between pairs of quantized vortex rings that are initially traveling in the same direction but with their axes offset by a variable impact parameter. The interaction of two circular rings of comparable radii produce outcomes that can be categorized into four regimes, dependent only on the impact parameter; the two rings can either miss each other on the inside or outside, or they can reconnect leading to final states consisting of either one or two deformed rings. The fraction of of energy went into ring deformations and the transverse component of velocity of the rings are analyzed for each regime. We find that rings of very similar radius only reconnect for a very narrow range of the impact parameter, much smaller than would be expected from geometrical cross-section alone. In contrast, when the radii of the rings are very different, the range of impact parameters producing a reconnection is close to the geometrical value. A...

  4. Quantized Abelian principle connections on Lorentzian manifolds

    Energy Technology Data Exchange (ETDEWEB)

    Benini, Marco [Pavia Univ. (Italy); Istituto Nazionale di Fisica Nucleare, Pavia (Italy); Hamburg Univ. (Germany). 2. Inst. fuer Theoretische Physik; Dappiaggi, Claudio [Pavia Univ. (Italy); Istituto Nazionale di Fisica Nucleare, Pavia (Italy); Schenkel, Alexander [Bergische Univ., Wuppertal (Germany). Fachgruppe Mathematik

    2013-03-15

    We construct a covariant functor from a category of Abelian principal bundles over globally hyperbolic spacetimes to a category of *-algebras that describes quantized principal connections. We work within an appropriate differential geometric setting by using the bundle of connections and we study the full gauge group, namely the group of vertical principal bundle automorphisms. Properties of our functor are investigated in detail and, similar to earlier works, it is found that due to topological obstructions the locality property of locally covariant quantum field theory is violated. Furthermore, we prove that, for Abelian structure groups containing a nontrivial compact factor, the gauge invariant Borchers- Uhlmann algebra of the vector dual of the bundle of connections is not separating on gauge equivalence classes of principal connections. We introduce a topological generalization of the concept of locally covariant quantum fields. As examples, we construct for the full subcategory of principal U(1)-bundles two natural transformations from singular homology functors to the quantum field theory functor that can be interpreted as the Euler class and the electric charge. In this case we also prove that the electric charges can be consistently set to zero, which yields another quantum field theory functor that satisfies all axioms of locally covariant quantum field theory.

  5. First-Quantized Theory of Expanding Universe from Field Quantization in Mini-Superspace

    CERN Document Server

    Ida, Daisuke

    2013-01-01

    We propose a new quantization scheme, which conceptually resembles the third-quantization scheme, for the spatially homogeneous and isotropic cosmological models in Einstein gravity coupled with a neutral massless scalar field. Our strategy is to specify a semi-Riemannian structure on the mini-superspace and to consider the quantum Klein-Gordon field on the mini-superspace. Then, the Hilbert space of this quantum system becomes inseparable, which causes the creation of infinite number of universes. To overcome this issue, we introduce a vector bundle structure on the Hilbert space and the connection of the vector bundle. Then, we can define a consistent unitary time evolution of the quantum universe in terms of the connection field on the vector bundle. By doing this, we are able to treat the quantum dynamics of a single-universe state. We also find an appropriate observable set constituting the CCR-algebra, and obtain the Schr\\"odinger equation for the wave function of the single-universe state. We show that...

  6. 基于向量量化谱分解的图像边缘融合算法%Image Edge Fusion Algorithm Based on Vector Quantization Spectrum Decomposition

    Institute of Scientific and Technical Information of China (English)

    熊朝松

    2015-01-01

    通过图像的边缘融合,挖掘图像中亮度变化明显的点,提高对远程图像的视觉特征分辨能力.传统的图像边缘融合算法采用灰阶量化边缘分解技术,由于图像边缘编码向量在码书中的排列是无序,导致边缘融合效果不好.提出一种改进的基于向量量化谱分解的图像边缘融合算法.采用向量量化谱分解技术,对信号与图像数据进行压缩,生成融合图像的灰度直方图,构建图像的向量量化边缘融合算子,实现算法改进.仿真结果表明,采用该算法能有效检测出图像的边缘亮点结构,保留了图像重要的结构属性,实现对图像边缘的准确检测,提高了峰值信噪比20 dB,展示了较高的边缘融合质量.%Through the edge of the image fusion, image mining in brightness changes obviously, improve the visual features of remote image resolution. Traditional image edge fusion algorithm using gray level quantization edge decomposition tech-nique, due to the arrangement of image edge encoding vectors in the codebook is in disorder, lead to the edge of fusion ef-fect is not good. A vector quantization of spectral decomposition of image edge fusion algorithm is proposed based on im-proved. Vector quantization of spectral decomposition technique, to compress the signal and image data, gray histogram gen-eration fusion image, construct the vector quantization of image edge fusion operator, improved algorithm. The simulation re-sults show that, by using this algorithm can effectively detect the edge of spot image structure, retains the structure proper-ties of important image, to achieve accurate detection of image edge, improves the peak signal-to-noise ratio of 20 dB, it has the high edge fusion quality.

  7. Perturbation theory in light-cone quantization

    Energy Technology Data Exchange (ETDEWEB)

    Langnau, A.

    1992-01-01

    A thorough investigation of light-cone properties which are characteristic for higher dimensions is very important. The easiest way of addressing these issues is by analyzing the perturbative structure of light-cone field theories first. Perturbative studies cannot be substituted for an analysis of problems related to a nonperturbative approach. However, in order to lay down groundwork for upcoming nonperturbative studies, it is indispensable to validate the renormalization methods at the perturbative level, i.e., to gain control over the perturbative treatment first. A clear understanding of divergences in perturbation theory, as well as their numerical treatment, is a necessary first step towards formulating such a program. The first objective of this dissertation is to clarify this issue, at least in second and fourth-order in perturbation theory. The work in this dissertation can provide guidance for the choice of counterterms in Discrete Light-Cone Quantization or the Tamm-Dancoff approach. A second objective of this work is the study of light-cone perturbation theory as a competitive tool for conducting perturbative Feynman diagram calculations. Feynman perturbation theory has become the most practical tool for computing cross sections in high energy physics and other physical properties of field theory. Although this standard covariant method has been applied to a great range of problems, computations beyond one-loop corrections are very difficult. Because of the algebraic complexity of the Feynman calculations in higher-order perturbation theory, it is desirable to automatize Feynman diagram calculations so that algebraic manipulation programs can carry out almost the entire calculation. This thesis presents a step in this direction. The technique we are elaborating on here is known as light-cone perturbation theory.

  8. Some effects of quantization on a noiseless phase-locked loop. [sampling phase errors

    Science.gov (United States)

    Greenhall, C. A.

    1979-01-01

    If the VCO of a phase-locked receiver is to be replaced by a digitally programmed synthesizer, the phase error signal must be sampled and quantized. Effects of quantizing after the loop filter (frequency quantization) or before (phase error quantization) are investigated. Constant Doppler or Doppler rate noiseless inputs are assumed. The main result gives the phase jitter due to frequency quantization for a Doppler-rate input. By itself, however, frequency quantization is impractical because it makes the loop dynamic range too small.

  9. FLOATING QUANTIZATION EFFECTS ON MULTIRATE SAMPLED-DATA NONLINEAR CONTROL SYSTEMS

    Institute of Scientific and Technical Information of China (English)

    Yu Hongwang; Wang Zhiming

    2007-01-01

    In this article, floating quantization effects on multirate sampled-data control systems are studied. It shows that the solutions of multirate digital feedback control systems with nonlinear plant and with floating quantization in the controller are uniformly ultimately bounded if the associated linear systems consisting of linearization of the plant and controller with no quantization are Schur stable. Moreover, it also shows that the difference between the response of multirate digital controllers without quantizers and the same plant with floating quantization in the controllers can be made as small as desired by selecting proper quantization level.

  10. Multiple-Description Coding by Dithered Delta-Sigma Quantization

    CERN Document Server

    Ostergaard, Jan

    2007-01-01

    We address the connection between the multiple-description (MD) problem and Delta-Sigma quantization. The inherent redundancy due to oversampling in Delta-Sigma quantization, and the simple linear-additive noise model resulting from dithered lattice quantization, allow us to construct a symmetric MD coding scheme. We show that the use of a noise shaping filter makes it possible to trade off central distortion for side distortion. Asymptotically as the dimension of the lattice vector quantizer and order of the noise shaping filter approach infinity, the entropy rate of the dithered Delta-Sigma quantization scheme approaches the symmetric two-channel MD rate-distortion function for a memoryless Gaussian source and MSE fidelity criterion, at any side-to-central distortion ratio and any resolution. In the optimal scheme, the infinite-order noise shaping filter must be minimum phase and have a piece-wise flat power spectrum with a single jump discontinuity. We further show that the optimal noise-shaping filter of ...

  11. Study on adaptive compressed sensing & reconstruction of quantized speech signals

    Science.gov (United States)

    Yunyun, Ji; Zhen, Yang

    2012-12-01

    Compressed sensing (CS) is a rising focus in recent years for its simultaneous sampling and compression of sparse signals. Speech signals can be considered approximately sparse or compressible in some domains for natural characteristics. Thus, it has great prospect to apply compressed sensing to speech signals. This paper is involved in three aspects. Firstly, the sparsity and sparsifying matrix for speech signals are analyzed. Simultaneously, a kind of adaptive sparsifying matrix based on the long-term prediction of voiced speech signals is constructed. Secondly, a CS matrix called two-block diagonal (TBD) matrix is constructed for speech signals based on the existing block diagonal matrix theory to find out that its performance is empirically superior to that of the dense Gaussian random matrix when the sparsifying matrix is the DCT basis. Finally, we consider the quantization effect on the projections. Two corollaries about the impact of the adaptive quantization and nonadaptive quantization on reconstruction performance with two different matrices, the TBD matrix and the dense Gaussian random matrix, are derived. We find that the adaptive quantization and the TBD matrix are two effective ways to mitigate the quantization effect on reconstruction of speech signals in the framework of CS.

  12. Energy-Constrained Optimal Quantization for Wireless Sensor Networks

    Directory of Open Access Journals (Sweden)

    Georgios B. Giannakis

    2008-02-01

    Full Text Available As low power, low cost, and longevity of transceivers are major requirements in wireless sensor networks, optimizing their design under energy constraints is of paramount importance. To this end, we develop quantizers under strict energy constraints to effect optimal reconstruction at the fusion center. Propagation, modulation, as well as transmitter and receiver structures are jointly accounted for using a binary symmetric channel model. We first optimize quantization for reconstructing a single sensor's measurement, and deriving the optimal number of quantization levels as well as the optimal energy allocation across bits. The constraints take into account not only the transmission energy but also the energy consumed by the transceiver's circuitry. Furthermore, we consider multiple sensors collaborating to estimate a deterministic parameter in noise. Similarly, optimum energy allocation and optimum number of quantization bits are derived and tested with simulated examples. Finally, we study the effect of channel coding on the reconstruction performance under strict energy constraints and jointly optimize the number of quantization levels as well as the number of channel uses.

  13. Selection of small color palette for color image quantization

    Science.gov (United States)

    Chau, Wing K.; Wong, S. K. M.; Yang, Xuedong; Wan, Shijie J.

    1992-05-01

    Two issues are involved in color image quantization: color palette selection and color mapping. A common practice for color palette selection is to minimize the color distortion for each pixel (the median-cut, the variance-based and the k-means algorithms). After the color palette has been chosen, a quantized image may be generated by mapping the original color of each pixel onto its nearest color in the color palette. Such an approach can usually produce quantized images of high quality with 128 or more colors. For 32 - 64 colors, the quality of the quantized images is often acceptable with the aid of dithering techniques in the color mapping process. For 8 - 16 color, however, the above statistical method for color selection becomes no longer suitable because of the great reduction of color gamut. In order to preserve the color gamut of the original image, one may want to select the colors in such a way that the convex hull formed by these colors in the RGB color space encloses most colors of the original image. Quantized images generated in such a geometrical way usually preserve a lot of image details, but may contain too much high frequency noises. This paper presents an effective algorithm for the selection of very small color palette by combining the strengths of the above statistical and geometrical approaches. We demonstrate that with the new method images of high quality can be produced by using only 4 to 8 colors.

  14. Direct comparison of fractional and integer quantized Hall resistance

    Science.gov (United States)

    Ahlers, Franz J.; Götz, Martin; Pierz, Klaus

    2017-08-01

    We present precision measurements of the fractional quantized Hall effect, where the quantized resistance {{R}≤ft[ 1/3 \\right]} in the fractional quantum Hall state at filling factor 1/3 was compared with a quantized resistance {{R}[2]} , represented by an integer quantum Hall state at filling factor 2. A cryogenic current comparator bridge capable of currents down to the nanoampere range was used to directly compare two resistance values of two GaAs-based devices located in two cryostats. A value of 1-(5.3  ±  6.3) 10-8 (95% confidence level) was obtained for the ratio ({{R}≤ft[ 1/3 \\right]}/6{{R}[2]} ). This constitutes the most precise comparison of integer resistance quantization (in terms of h/e 2) in single-particle systems and of fractional quantization in fractionally charged quasi-particle systems. While not relevant for practical metrology, such a test of the validity of the underlying physics is of significance in the context of the upcoming revision of the SI.

  15. Probabilistic distance-based quantizer design for distributed estimation

    Science.gov (United States)

    Kim, Yoon Hak

    2016-12-01

    We consider an iterative design of independently operating local quantizers at nodes that should cooperate without interaction to achieve application objectives for distributed estimation systems. We suggest as a new cost function a probabilistic distance between the posterior distribution and its quantized one expressed as the Kullback Leibler (KL) divergence. We first present the analysis that minimizing the KL divergence in the cyclic generalized Lloyd design framework is equivalent to maximizing the logarithmic quantized posterior distribution on the average which can be further computationally reduced in our iterative design. We propose an iterative design algorithm that seeks to maximize the simplified version of the posterior quantized distribution and discuss that our algorithm converges to a global optimum due to the convexity of the cost function and generates the most informative quantized measurements. We also provide an independent encoding technique that enables minimization of the cost function and can be efficiently simplified for a practical use of power-constrained nodes. We finally demonstrate through extensive experiments an obvious advantage of improved estimation performance as compared with the typical designs and the novel design techniques previously published.

  16. Video signal coding with DCT and vector quantization

    Science.gov (United States)

    Bellifemine, Fabio; Picco, Romualdo

    1994-02-01

    In this paper, an image coding scheme using the Discrete Cosine Transform is analyzed when the transform coefficients are vector quantized. The coding method is based on the known scheme proposed by W. Chen which sorts the picture blocks into classes according to the level of image activity. The coding scheme is modified to allow for vector quantization of the ac coefficients, in particular a Pyramid Vector Quantizer (PVQ) is used. This is based on the statistical and geometric properties of a Laplacian source which, in fact, is the best model for the ac coefficients of the two-dimensional Discrete Cosine Transform (2D-DCT) of an image. A method for forming almost statistically independent vectors is also suggested and improves quantization performance. Images are encoded with both the PVQ and standard scalar quantizer transform coders, demonstrating that the PVQ coder reduces the mean square encoding error and improves image quality. In particular, emphasis is given to how the use of fractional bit rates affects the objective and subjective gains obtained. The results presented (i.e. mean square error values and printed images) have been obtained experimentally, working with a statistical criterion in a group of images whose size was in accordance with the 50 Hz CCIR Recommendation 601 Standard.

  17. 判别式 Bo W分析结合自适应码本学习的人体动作识别%Application of discriminant BoW analysis combined with adaptive codebook learning in human recognition

    Institute of Scientific and Technical Information of China (English)

    蔡琼; 陈鹏慧; 郭涛

    2016-01-01

    针对一般聚类获得的码本缺乏判别性表示导致不能有效进行人体动作识别的问题,提出了一种新的自适应码本学习方法,该方法将判别式词袋(bag of words,BoW)动作表示和自适应码本学习结合,增强了码本的表示能力和特征的判别性。为了有效求解非凸目标函数,提出基于轮换优化迭代方法,即固定码本更新判别矩阵,然后判别矩阵更新固定码本,直至满足终止迭代条件,该方法为自适应码本学习提供了技术支持。仿真实验采用KTH、Hollywood2、芭蕾、i3 Dpost数据库进行判别比较,识别率比现有典型方法平均提高了4%左右,学习到的码本在特征空间中具有良好的判别性能。相比于基于光流、方向梯度直方图(histograms of oriented gradients, HOG)等方法,计算复杂度更低,实用性更好。%As the problem of ineffective human action recognition caused by lack of judgment representation of codebook ob-tained by general clustering,this paper proposed a new adaptive codebook learning method,combined discriminant bag of words with adaptive codebook learning,which had enhanced the ability to represent features of codebook discriminant.In order to ef-fectively solve the non-convex objective function,it proposed iteration of rotational optimization,that was the fixed codebook up-dated the judgment matrix,and then the judgment matrix updated the fixed codebook until it met the conditions for termination of the iteration.This method provided technical support for the adaptive codebook learning.In the simulation experiments,it tested five data sets KTH,Hollywood2,ballet,i3Dpost and facial expressions.The experimental result is about 4% recognition rate averagely higher than the existing typical methods.The learned codebook has good discrimination performance in the fea-ture space.Compared with optical flow method,the method based on the histograms of oriented gradients (HOG

  18. Violation of KMS condition along Rindler trajectory in polymer quantization

    CERN Document Server

    Hossain, Golam Mortuza

    2015-01-01

    Existence of Unruh effect is often understood from the property of two-point function along Rindler trajectory where it satisfies KMS condition. In particular, it exhibits the so-called KMS periodicity along imaginary time direction. Corresponding period is then identified with reciprocal of Unruh temperature times Boltzmann constant. We show here that the two-point function including leading order perturbative corrections due to polymer quantization, the quantization method used in loop quantum gravity, violates KMS condition in low-energy regime. This violation is caused by correction terms which are not Lorentz invariants. Consequently, polymer corrected two-point function along Rindler trajectory looses its thermal interpretation. We discuss its implications on existence of Unruh effect in the context of polymer quantization.

  19. Image Compression and Watermarking scheme using Scalar Quantization

    CERN Document Server

    Swamy, Kilari Veera; Reddy, Y V Bhaskar; Kumar, S Srinivas; 10.5121/ijngn.2010.2104

    2010-01-01

    This paper presents a new compression technique and image watermarking algorithm based on Contourlet Transform (CT). For image compression, an energy based quantization is used. Scalar quantization is explored for image watermarking. Double filter bank structure is used in CT. The Laplacian Pyramid (LP) is used to capture the point discontinuities, and then followed by a Directional Filter Bank (DFB) to link point discontinuities. The coefficients of down sampled low pass version of LP decomposed image are re-ordered in a pre-determined manner and prediction algorithm is used to reduce entropy (bits/pixel). In addition, the coefficients of CT are quantized based on the energy in the particular band. The superiority of proposed algorithm to JPEG is observed in terms of reduced blocking artifacts. The results are also compared with wavelet transform (WT). Superiority of CT to WT is observed when the image contains more contours. The watermark image is embedded in the low pass image of contourlet decomposition. ...

  20. Inequivalent quantization in the field of a ferromagnetic wire

    CERN Document Server

    Giri, Pulak Ranjan

    2007-01-01

    We argue that it is possible to bind neutral atom (NA) to the ferromagnetic wire (FW) by inequivalent quantization of the Hamiltonian. We follow the well known von Neumann's method of self-adjoint extensions (SAE) to get this inequivalent quantization, which is characterized by a parameter \\Sigma\\in\\mathbb{R}({mod}2\\pi). There exists a single bound state for the coupling constant \\eta^2\\in[0,1). Although this bound state should not occur due to the existence of classical scale symmetry in the problem. But since quantization procedure breaks this classical symmetry, bound state comes out as a scale in the problem leading to scaling anomaly. We also discuss the strong coupling region \\eta^2< 0, which supports bound state making the problem re-normalizable.

  1. Polarization-free Quantization of Linear Field Theories

    CERN Document Server

    Lanéry, Suzanne

    2016-01-01

    It is well-known that there exist infinitely-many inequivalent representations of the canonical (anti)-commutation relations of Quantum Field Theory (QFT). A way out, suggested by Algebraic QFT, is to instead define the quantum theory as encompassing all possible (abstract) states. In the present paper, we describe a quantization scheme for general linear (aka. free) field theories that can be seen as intermediate between traditional Fock quantization and full Algebraic QFT, in the sense that: * it provides a constructive, explicit description of the resulting space of quantum states; * it does not require the choice of a polarization, aka. the splitting of classical solutions into positive vs. negative-frequency modes: in fact, any Fock representation corresponding to a "reasonable" choice of polarization is naturally embedded; * it supports the implementation of a "large enough" class of linear symplectomorphisms of the classical, infinite-dimensional phase space. The proposed quantization (like Algebraic Q...

  2. Polymer quantization, stability and higher-order time derivative terms

    CERN Document Server

    Cumsille, Patricio; Ossandon, Sebastian; Reyes, Camilo

    2015-01-01

    The stability of higher-order time derivative theories using the polymer extension of quantum mechanics is studied. First, we focus on the well-known Pais-Uhlenbeck model and by casting the theory into the sum of two decoupled harmonic oscillators we show that the energy spectrum is composed with positive and negative energy parts. The Schrodinger quantization of the model with creation and annihilations operators leads to a theory with unbounded Hamiltonian that can be interpreted in terms of normal particles and Lee-Wick-like particles responsible for the instability. We investigate whether the fundamental discreetness implicit in the polymer quantization can regularize the effects of the negative energies introduced by the Lee-Wick-like particles which are associated to a high-energy scale. Precisely, we show that the polymer quantization leads to a positive defined Hamiltonian whose stability is improved as the number of Lee-Wick-like particles grows.

  3. A Second Quantized Approach to the Rabi Problem

    Science.gov (United States)

    Baldiotti, M. C.; Molina, C.

    2017-10-01

    In the present work, the Rabi Problem, involving the response of a spin 1/2 particle subjected to a magnetic field, is considered in a second quantized approach. In this concrete physical scenario, we show that the second quantization procedure can be applied directly in a non-covariant theory. The proposed development explicits not only the relation between the full quantum treatment of the problem and the semiclassical Rabi model, but also the connection of these approaches with the Jaynes-Cummings model. The consistency of the method is checked in the semiclassical limit. The treatment is then extended to the matter component of the Rabi problem so that the Schrödinger equation is directly quantized. Considering the spinorial field, the appearance of a negative energy sector implies a specific identification between Schrödinger's and Maxwell's theories. The generalized theory is consistent, strictly quantum and non-relativistic.

  4. Van Vleck correction generalization for complex correlators with multilevel quantization

    CERN Document Server

    Benkevitch, L V; Lonsdale, C J; Cappallo, R J; Oberoi, D; Erickson, P J; Baker, K A V

    2016-01-01

    Remote sensing with phased antenna arrays is based on measurement of the cross-correlations between the signals from each antenna pair. Digital correlators have systematic errors due to the quantization losses. The correlation errors allow substantial abatement based on the assumption that the analog signals are stochastic processes sampled from a statistical distribution (usually the Gaussian). The correlation correction technique is named after Van Vleck who was the first to apply it to two-level clipping quantizers. The correction is especially important for high correlation levels, e.g. in studies of solar radio emissions. We offer a generalized method that for every antenna pair inputs the quantized signals' covariance and standard deviations, and outputs high-precision estimates of the analog correlation. Although correlation correction methods have been extensively investigated in the past, there are several problems that, as far as we know, have not been published yet. We consider a very general quant...

  5. Hitchin's connection, Toeplitz operators, and symmetry invariant deformation quantization

    DEFF Research Database (Denmark)

    Andersen, Jørgen Ellegaard

    2012-01-01

    We introduce the notion of a rigid family of Kähler structures on a symplectic manifold. We then prove that a Hitchin connection exists for any rigid holomorphic family of Kähler structures on any compact pre-quantizable symplectic manifold which satisfies certain simple topological constraints....... Using Toeplitz operators we prove that the Hitchin connection induces a unique formal connection on smooth functions on the symplectic manifold. Parallel transport of this formal connection produces equivalences between the corresponding Berezin–Toeplitz deformation quantizations. In the cases where...... the Hitchin connection is projectively flat, the formal connections will be flat and we get a symmetry-invariant formal quantization. If a certain cohomological condition is satisfied a global trivialization of this algebra bundle is constructed. As a corollary we get a symmetry-invariant deformation...

  6. On the Performance of Cooperative Spectrum Sensing under Quantization

    CERN Document Server

    Han, Weijia; Li, Zan; Zhang, Yan; Liu, Qin

    2011-01-01

    In cognitive radio, the cooperative spectrum sensing (CSS) plays a key role in determining the performance of secondary networks. However, there have not been feasible approaches that can analytically calculate the performance of CSS with regard to the multi-level quantization. In this paper, we not only show the cooperative false alarm probability and cooperative detection probability impacted by quantization, but also formulate them by two closed form expressions. These two expressions enable the calculation of cooperative false alarm probability and cooperative detection probability tractable efficiently, and provide a feasible approach for optimization of sensing performance. Additionally, to facilitate this calculation, we derive Normal approximation for evaluating the sensing performance conveniently. Furthermore, two optimization methods are proposed to achieve the high sensing performance under quantization.

  7. Unified framework and algorithm for quantized compressed sensing

    CERN Document Server

    Yang, Zai; Zhang, Cishen

    2012-01-01

    Compressed sensing (CS) studies the recovery of high dimensional signals from their low dimensional linear measurements under a sparsity prior. This paper is focused on the CS problem with quantized measurements. There have been research results dealing with different scenarios including a single/multiple bits per measurement, noiseless/noisy environment, and an unsaturated/saturated quantizer. While the existing methods are only for one or more specific cases, this paper presents a framework to unify all the above mentioned scenarios of the quantized CS problem. Under the unified framework, a variational Bayesian inference based algorithm is proposed which is applicable to the signal recovery of different application cases. Numerical simulations are carried out to illustrate the improved signal recovery accuracy of the unified algorithm in comparison with state-of-the-art methods for both multiple and single bit CS problems.

  8. Quantization of gauge fields, graph polynomials and graph homology

    Energy Technology Data Exchange (ETDEWEB)

    Kreimer, Dirk, E-mail: kreimer@physik.hu-berlin.de [Humboldt University, 10099 Berlin (Germany); Sars, Matthias [Humboldt University, 10099 Berlin (Germany); Suijlekom, Walter D. van [Radboud University Nijmegen, 6525 AJ Nijmegen (Netherlands)

    2013-09-15

    We review quantization of gauge fields using algebraic properties of 3-regular graphs. We derive the Feynman integrand at n loops for a non-abelian gauge theory quantized in a covariant gauge from scalar integrands for connected 3-regular graphs, obtained from the two Symanzik polynomials. The transition to the full gauge theory amplitude is obtained by the use of a third, new, graph polynomial, the corolla polynomial. This implies effectively a covariant quantization without ghosts, where all the relevant signs of the ghost sector are incorporated in a double complex furnished by the corolla polynomial–we call it cycle homology–and by graph homology. -- Highlights: •We derive gauge theory Feynman from scalar field theory with 3-valent vertices. •We clarify the role of graph homology and cycle homology. •We use parametric renormalization and the new corolla polynomial.

  9. Low Complexity Integer Transform and Adaptive Quantization Optimization

    Institute of Scientific and Technical Information of China (English)

    Si-Wei Ma; Wen Gao

    2006-01-01

    In this paper, a new low complexity integer transform is proposed, which has been adopted by AVS1-PT. The proposed transform can enable AVS1-P7 to share the same quantization/dequantization table with AVS1-P2. As the bases of the proposed transform coefficients are very close, the transform normalization can be implemented only on the encoder side and the dequantization table size can be reduced compared with the transform used in H.264/MPEG-4 AVC. Along with the feature of the proposed transform, adaptive dead-zone quantization optimization for the proposed transform is studied.Experimental results show that the proposed integer transform has similar coding performance compared with the transform used in H.264/MPEG-4 AVC, and would gain near 0.1dB with the adaptive dead-zone quantization optimization.

  10. Effective Field Theory of Fractional Quantized Hall Nematics

    Energy Technology Data Exchange (ETDEWEB)

    Mulligan, Michael; /MIT, LNS; Nayak, Chetan; /Station Q, UCSB; Kachru, Shamit; /Stanford U., Phys. Dept. /SLAC

    2012-06-06

    We present a Landau-Ginzburg theory for a fractional quantized Hall nematic state and the transition to it from an isotropic fractional quantum Hall state. This justifies Lifshitz-Chern-Simons theory - which is shown to be its dual - on a more microscopic basis and enables us to compute a ground state wave function in the symmetry-broken phase. In such a state of matter, the Hall resistance remains quantized while the longitudinal DC resistivity due to thermally-excited quasiparticles is anisotropic. We interpret recent experiments at Landau level filling factor {nu} = 7/3 in terms of our theory.

  11. Quantization of the radiation field in an anisotropic dielectric medium

    Institute of Scientific and Technical Information of China (English)

    Li Wei; Liu Shi-Bing; Yang Wei

    2009-01-01

    There are both loss and dispersion characteristics for most dielectric media. In quantum theory the loss in medium is generally described by Langevin force in the Langevin noise (LN) scheme by which the quantization of the radiation field in various homogeneous absorbing dielectrics can be successfully actualized. However, it is invalid for the anisotropic dispersion medium. This paper extends the LN theory to an anisotropic dispersion medium and presented the quantization of the radiation field as well as the transformation relation between the homogeneous and anisotropic dispersion media.

  12. A Numerical Study of Quantization-Based Integrators

    Directory of Open Access Journals (Sweden)

    Barros Fernando

    2014-01-01

    Full Text Available Adaptive step size solvers are nowadays considered fundamental to achieve efficient ODE integration. While, traditionally, ODE solvers have been designed based on discrete time machines, new approaches based on discrete event systems have been proposed. Quantization provides an efficient integration technique based on signal threshold crossing, leading to independent and modular solvers communicating through discrete events. These solvers can benefit from the large body of knowledge on discrete event simulation techniques, like parallelization, to obtain efficient numerical integration. In this paper we introduce new solvers based on quantization and adaptive sampling techniques. Preliminary numerical results comparing these solvers are presented.

  13. Semiclassical Quantization by Pade Approximant to Periodic Orbit Sums

    CERN Document Server

    Main, J; Belkic, D; Taylor, H S; Belkic, Dz.

    1999-01-01

    Periodic orbit quantization requires an analytic continuation of non-convergent semiclassical trace formulae. We propose a method for semiclassical quantization based upon the Pade approximant to the periodic orbit sums. The Pade approximant allows the re-summation of the typically exponentially divergent periodic orbit terms. The technique does not depend on the existence of a symbolic dynamics and can be applied to both bound and open systems. Numerical results are presented for two different systems with chaotic and regular classical dynamics, viz. the three-disk scattering system and the circle billiard.

  14. Quantization condition from exact WKB for difference equations

    CERN Document Server

    Kashani-Poor, Amir-Kian

    2016-01-01

    A well-motivated conjecture states that the open topological string partition function on toric geometries in the Nekrasov-Shatashvili limit is annihilated by a difference operator called the quantum mirror curve. Recently, the complex structure variables parameterizing the curve, which play the role of eigenvalues for related operators, were conjectured to satisfy a quantization condition non-perturbative in the NS parameter $\\hbar$. Here, we argue that this quantization condition arises from requiring single-valuedness of the partition function, combined with the requirement of smoothness in the parameter $\\hbar$. To determine the monodromy of the partition function, we study the underlying difference equation in the framework of exact WKB.

  15. Quantization analysis of speckle intensity measurements for phase retrieval

    DEFF Research Database (Denmark)

    Maallo, Anne Margarette S.; Almoro, Percival F.; Hanson, Steen Grüner

    2010-01-01

    Speckle intensity measurements utilized for phase retrieval (PR) are sequentially taken with a digital camera, which introduces quantization error that diminishes the signal quality. Influences of quantization on the speckle intensity distribution and PR are investigated numerically...... and experimentally in the static wavefront sensing setup. Resultsshowthat 3 to 4 bits are adequate to represent the speckle intensities and yield acceptable reconstructions at relatively fast convergence rates. Computer memory requirements may be eased down by 2.4 times if a 4 bit instead of an 8 bit camera is used...

  16. A Geometrical Transformations Resistant Digital Watermarking Based on Quantization

    Institute of Scientific and Technical Information of China (English)

    SHI Lei; HONG Fan; LIU Wei-qun; HU Yu-ping; CHEN Zhuo

    2005-01-01

    A geometrical transformations resistant digital image watermarking based on quantization is described. Taking advantage of the rotation, scale and translation invariants of discrete Fourier transform(DFT), each watermark bit is embedded into each homocentric circles around the zero frequency term in DFT domain by quantizing the magnitude vector of Fourier spectrum. The embedded sequence can be extracted by "majority principles" without restoring to the original unmarked image. The experimental results show that the watermark is invisible and robust to any combination of geometrical transformations or common image processing techniques.

  17. Linking loop quantum gravity quantization ambiguities with phenomenology

    CERN Document Server

    Brahma, Suddhasattwa; Amelino-Camelia, Giovanni; Marciano, Antonino

    2016-01-01

    Fundamental quantum gravity theories are known to be notoriously difficult to extract viable testable predictions out of. In this paper, we aim to incorporate putative quantum corrections coming from loop quantum gravity in deriving modified dispersion relations for particles on a deformed Minkowski spacetime. We show how different choices of the Immirzi parameter can, in some cases, serendipitously lead to different outcomes for such modifications, depending on the quantization scheme chosen. This allows one to differentiate between these quantization choices via testable phenomenological predictions.

  18. Deparametrization and path integral quantization of cosmological models

    CERN Document Server

    Simeone, Claudio

    2001-01-01

    The problem of time is a central feature of quantum cosmology: differing from ordinary quantum mechanics, in cosmology there is nothing "outside" the system which plays the role of clock, and this makes difficult the obtention of a consistent quantization. A possible solution is to assume that a subset of the variables describing the state of the universe can be a clock for the remaining of the system. Following this line, in this book a new proposal consisting in the previous identification of time by means of gauge fixation is applied to the quantization of homogeneous cosmological models. B

  19. On precanonical quantization of gravity in spin connection variables

    Energy Technology Data Exchange (ETDEWEB)

    Kanatchikov, I. V. [National Center of Quantum Information in Gdansk (KCIK), 81-824 Sopot (Poland)

    2013-02-21

    The basics of precanonical quantization and its relation to the functional Schroedinger picture in QFT are briefly outlined. The approach is then applied to quantization of Einstein's gravity in vielbein and spin connection variables and leads to a quantum dynamics described by the covariant Schroedinger equation for the transition amplitudes on the bundle of spin connection coefficients over space-time, that yields a novel quantum description of space-time geometry. A toy model of precanonical quantum cosmology based on the example of flat FLRW universe is considered.

  20. A Quantized Spacetime Based on $Spin(3,1)$ Symmetry

    CERN Document Server

    Chen, Pisin; Hu, Yao-Chieh

    2016-01-01

    We introduce a new type of spacetime quantization based on the spinorial description suggested by loop quantum gravity. Specifically, we build our theory on a string theory inspired $Spin(3,1)$ worldsheet action. Because of its connection with quantum gravity theories, our proposal may in principle link back to string theory, connect to loop quantum gravity where $SU(2)$ is suggested as the fundamental symmetry, or serve as a Lorentzian spin network. We derive the generalized uncertainty principle and demonstrate the holographic nature of our theory. Due to the quantization of spacetime, geodesics in our theory are fuzzy, but the fuzziness is shown to be much below conceivable astrophysical bounds.

  1. Quantized biopolymer translocation through nanopores: departure from simple scaling

    CERN Document Server

    Melchionna, Simone; Fyta, Maria; Kaxiras, Efthimios; Succi, Sauro

    2009-01-01

    We discuss multiscale simulations of long biopolymer translocation through wide nanopores that can accommodate multiple polymer strands. The simulations provide clear evidence of folding quantization, namely, the translocation proceeds through multi-folded configurations characterized by a well-defined integer number of folds. As a consequence, the translocation time acquires a dependence on the average folding number, which results in a deviation from the single-exponent power-law characterizing single-file translocation through narrow pores. The mechanism of folding quantization allows polymers above a threshold length (approximately $1,000$ persistence lengths for double-stranded DNA) to exhibit cooperative behavior and as a result to translocate noticeably faster.

  2. Nucleon form factors in the canonically quantized Skyrme model

    Energy Technology Data Exchange (ETDEWEB)

    Acus, A.; Norvaisas, E. [Lithuanian Academy of Sciences, Vilnius (Lithuania). Inst. of Theoretical Physics and Astronomy; Riska, D.O. [Helsinki Univ. (Finland). Dept. of Physics; Helsinki Univ. (Finland). Helsinki Inst. of Physics

    2001-08-01

    The explicit expressions for the electric, magnetic, axial and induced pseudoscalar form factors of the nucleons are derived in the ab initio quantized Skyrme model. The canonical quantization procedure ensures the existence of stable soliton solutions with good quantum numbers. The form factors are derived for representations of arbitrary dimension of the SU(2) group. After fixing the two parameters of the model, f{sub {pi}} and e, by the empirical mass and electric mean square radius of the proton, the calculated electric and magnetic form factors are fairly close to the empirical ones, whereas the the axial and induced pseudoscalar form factors fall off too slowly with momentum transfer. (orig.)

  3. The $\\alpha$ particle as a canonically quantized multiskyrmion

    CERN Document Server

    Acus, A; Riska, D O

    2006-01-01

    The rational map approximation to the solution to the SU(2) Skyrme model with baryon number B=4 is canonically quantized. The quantization procedure leads to anomalous breaking of the chiral symmetry, and exponential falloff of the energy density of the soliton at large distances. The model is extended to SU(2) representations of arbitrary dimension. These soliton solutions capture the double node feature of the empirical $\\alpha$ particle charge form factor, but as expected lead to a too compact matter distribution. Comparison to phenomenology indicates a preference for the fundamental representation.

  4. Nucleon form factors in the canonically quantized Skyrme model

    CERN Document Server

    Acus, A; Riska, D O

    2001-01-01

    The explicit expressions for the electric, magnetic, axial and induced pseudoscalar form factors of the nucleons are derived in the {\\it ab initio} quantized Skyrme model. The canonical quantization procedure ensures the existence of stable soliton solutions with good quantum numbers. The form factors are derived for representations of arbitrary dimension of the SU(2) group. After fixing the two parameters of the model, $f_\\pi$ and $e$, by the empirical mass and electric mean square radius of the proton, the calculated electric and magnetic form factors are fairly close to the empirical ones, whereas the the axial and induced pseudoscalar form factors fall off too slowly with momentum transfer.

  5. Cyclic cocycles on deformation quantizations and higher index theorems

    CERN Document Server

    Pflaum, M; Tang, X

    2008-01-01

    We construct a nontrivial cyclic cocycle on the Weyl algebra of a symplectic vector space. Using this cyclic cocycle we construct an explicit, local, quasi-isomorphism from the complex of differential forms on a symplectic manifold to the complex of cyclic cochains of any formal deformation quantization thereof. We prove an algebraic higher index theorem by computing the pairing between such cyclic cocycles and the $K$-theory of the formal deformation quantization. As an application, we obtain the analytic higher index theorem of Connes--Moscovici.

  6. Holonomy Operator and Quantization Ambiguities on Spinor Space

    CERN Document Server

    Livine, Etera R

    2013-01-01

    We construct the holonomy-flux operator algebra in the recently developed spinor formulation of loop gravity. We show that, when restricting to SU(2)-gauge invariant operators, the familiar grasping and Wilson loop operators are written as composite operators built from the gauge-invariant `generalized ladder operators' recently introduced in the U(N) approach to intertwiners and spin networks. We comment on quantization ambiguities that appear in the definition of the holonomy operator and use these ambiguities as a toy model to test a class of quantization ambiguities which is present in the standard regularization and definition of the Hamiltonian constraint operator in loop quantum gravity.

  7. Phase space reduction and vortex statistics: An anyon quantization ambiguity

    Energy Technology Data Exchange (ETDEWEB)

    Allen, T.J.; Bordner, A.J.; Crossley, D.B. (Department of Physics, University of Wisconsin, 1150 University Avenue, Madison, Wisconsin 53706 (United States))

    1994-06-15

    We examine the quantization of the motion of two charged vortices in a Ginzburg-Landau theory for the fractional quantum Hall effect recently proposed by the first two authors. The system has two second-class constraints which can be implemented either in the reduced phase space or Dirac-Gupta-Bleuler formalism. Using the intrinsic formulation of statistics, we show that these two ways of implementing the constraints are inequivalent unless the vortices are quantized with conventional statistics, either fermionic or bosonic.

  8. Noncommutative spectral geometry, algebra doubling and the seeds of quantization

    CERN Document Server

    Sakellariadou, Mairi; Vitiello, Giuseppe

    2011-01-01

    A physical interpretation of the two-sheeted space, the most fundamental ingredient of noncommutative spectral geometry proposed by Connes as an approach to unification, is presented. It is shown that the doubling of the algebra is strictly related to dissipation. As a consequence, the doubling of the algebra is intimately related to the gauge structure of the theory. In a regime of completely deterministic dynamics, dissipation seems also to play a key role in the quantization of the theory, following 't Hooft's conjecture. It is thus argued that Connes' classical construction carries implicit in its feature of the doubling of the algebra the seeds of quantization.

  9. Exact quantization conditions for the relativistic Toda lattice

    CERN Document Server

    Hatsuda, Yasuyuki

    2015-01-01

    Inspired by recent connections between spectral theory and topological string theory, we propose exact quantization conditions for the relativistic Toda lattice of N particles. These conditions involve the Nekrasov-Shatashvili free energy, which resums the perturbative WKB expansion, but they require in addition a non-perturbative contribution, which is related to the perturbative result by an S-duality transformation of the Planck constant. We test the quantization conditions against explicit calculations of the spectrum for N=3. Our proposal can be generalized to arbitrary toric Calabi--Yau manifolds and might solve the corresponding quantum integrable system of Goncharov and Kenyon.

  10. Exact quantization conditions for the relativistic Toda lattice

    Science.gov (United States)

    Hatsuda, Yasuyuki; Mariño, Marcos

    2016-05-01

    Inspired by recent connections between spectral theory and topological string theory, we propose exact quantization conditions for the relativistic Toda lattice of N particles. These conditions involve the Nekrasov-Shatashvili free energy, which resums the perturbative WKB expansion, but they require in addition a non-perturbative contribution, which is related to the perturbative result by an S-duality transformation of the Planck constant. We test the quantization conditions against explicit calculations of the spectrum for N = 3. Our proposal can be generalized to arbitrary toric Calabi-Yau manifolds and might solve the corresponding quantum integrable system of Goncharov and Kenyon.

  11. Quantized stabilization of wireless networked control systems with packet losses.

    Science.gov (United States)

    Qu, Feng-Lin; Hu, Bin; Guan, Zhi-Hong; Wu, Yong-Hong; He, Ding-Xin; Zheng, Ding-Fu

    2016-09-01

    This paper considers stabilization of discrete-time linear systems, where wireless networks exist for transmitting the sensor and controller information. Based on Markov jump systems, we show that the coarsest quantizer that stabilizes the WNCS is logarithmic in the sense of mean square quadratic stability and the stabilization of this system can be transformed into the robust stabilization of an equivalent uncertain system. Moreover, a method of optimal quantizer/controller design in terms of linear matrix inequality is presented. Finally, a numerical example is provided to illustrate the effectiveness of the developed theoretical results.

  12. Laughlin's argument for the quantized thermal Hall effect

    CERN Document Server

    Nakai, Ryota; Nomura, Kentaro

    2016-01-01

    We extend Laughlin's magnetic-flux-threading argument to the quantized thermal Hall effect. A proper analogue of Laughlin's adiabatic magnetic-flux threading process for the case of the thermal Hall effect is given in terms of an external gravitational field. From the perspective of the edge theories of quantum Hall systems, the quantized thermal Hall effect is closely tied to the breakdown of large diffeomorphism invariance, that is, a global gravitational anomaly. In addition, we also give an argument from the bulk perspective in which a free energy, decomposed into its Fourier modes, is adiabatically transferred under an adiabatic process involving external gravitational perturbations.

  13. Comments on a full quantization of the torus

    CERN Document Server

    Velhinho, J M

    1998-01-01

    Gotay showed that a representation of the whole Poisson algebra of the torus given by geometric quantization is irreducible with respect to the most natural overcomplete set of observables. We study this representation and argue that it cannot be considered as physically acceptable, since classically bounded observables are quantized by operators with unbounded spectrum. This in turn can be traced back to the non implementation of functional relations among observables. Effectively, the latter amounts to lifting the constraints that compactify both directions in the torus.

  14. Examples of Enhanced Quantization: Bosons, Fermions, and Anyons

    CERN Document Server

    Adorno, T C

    2014-01-01

    Enhanced quantization offers a different classical/quantum connection than that of canonical quantization in which $\\hbar >0$ throughout. This result arises when the only allowed Hilbert space vectors allowed in the quantum action functional are coherent states, which leads to the classical action functional augmented by additional terms of order $\\hbar$. Canonical coherent states are defined by unitary transformations of a fixed, fiducial vector. While Gaussian vectors are commonly used as fiducial vectors, they cannot be used for all systems. We focus on choosing fiducial vectors for several systems including bosons, fermions, and anyons.

  15. Berezin-Toeplitz Quantization for Compact Kähler Manifolds. A Review of Results

    Directory of Open Access Journals (Sweden)

    Martin Schlichenmaier

    2010-01-01

    Full Text Available This article is a review on Berezin-Toeplitz operator and Berezin-Toeplitz deformation quantization for compact quantizable Kähler manifolds. The basic objects, concepts, and results are given. This concerns the correct semiclassical limit behaviour of the operator quantization, the unique Berezin-Toeplitz deformation quantization (star product, covariant and contravariant Berezin symbols, and Berezin transform. Other related objects and constructions are also discussed.

  16. Wigner function and the entanglement of a quantized Bessel-Gaussian vortex state of a quantized radiation field

    Institute of Scientific and Technical Information of China (English)

    Zhu Kai-Cheng; Li Shao-Xin; Tang Ying; Zheng Xiao-Juan; Tang Hui-Qin

    2012-01-01

    A new kind of quantum non-Gaussian state with a vortex structure,termed a Bessel-Gaussian vortex state,is constructed,which is an eigenstate of the sum of squared annihilation operators a2 + b2.The Wigner function of the quantum vortex state is derived and exhibits negativity which is an indication of nonclassicality.It is also found that a quantized vortex state is always in entanglement.And a scheme for generating such quantized vortex states is proposed.

  17. Improved stability and performance from sigma-delta modulators using 1-bit vector quantization

    DEFF Research Database (Denmark)

    Risbo, Lars

    1993-01-01

    A novel class of sigma-delta modulators is presented. The usual scalar 1-b quantizer in a sigma-delta modulator is replaced by a 1-b vector quantizer with a N-dimensional input state-vector from the linear feedback filter. Generally, the vector quantizer changes the nonlinear dynamics...

  18. A Third-Quantized Approach to the Large-N Field Models

    CERN Document Server

    Maslov, V P

    1998-01-01

    Large-N field systems are considered from an unusual point of view. The Hamiltonian is presented in a third-quantized form analogously to the second-quantized formulation of the quantum theory of many particles. The semiclassical approximation is applied to the third-quantized Hamiltonian. The advantages of this approach in comparison with 1/N-expansion are discussed.

  19. One-dimensional relativistic dissipative system with constant force and its quantization

    CERN Document Server

    López, G; Hernández, H; L\\'opez, Gustavo; L\\'opez, Xaman-Ek; Hern\\'andez, Hector

    2005-01-01

    For a relativistic particle under a constant force and a linear velocity dissipation force, a constant of motion is found. Problems are shown for getting the Hamiltoninan of this system. Thus, the quantization of this system is carried out through the constant of motion and using the quantization of the velocity variable. The dissipative relativistic quantum bouncer is outlined within this quantization approach.

  20. One-Dimensional Relativistic Dissipative System with Constant Force and its Quantization

    Science.gov (United States)

    López, G.; López, X. E.; Hernández, H.

    2006-04-01

    For a relativistic particle under a constant force and a linear velocity dissipation force, a constant of motion is found. Problems are shown for getting the Hamiltonian of this system. Thus, the quantization of this system is carried out through the constant of motion and using the quantization on the velocity variable. The dissipative relativistic quantum bouncer is outlined within this quantization approach.

  1. Sigma-delta modulator: loop filters and quantization noise

    Directory of Open Access Journals (Sweden)

    Golub V. S.

    2013-05-01

    Full Text Available In this paper the sigma-delta modulator was analyzed with the use of simulation. In particular, the author studied dependence of the quantization noise on the loop filtration. The obtained results explain certain operation features of the modulator and make it possible to give advice as to its application.

  2. A topological model of electromagnetism: quantization of the electric change

    Energy Technology Data Exchange (ETDEWEB)

    Ranada, A.F.

    1991-01-01

    It is shown that a topological structure which underlies the Maxwell equations gives a mechanism of quantization of the electric charge, the fundamental charge being equal to 1/4 pi in natural units. This value is very close to 14/15 times the electron charge, the corresponding fine structure constant being equal to 1/157.9. (author)

  3. Shouldn't there be an antithesis to quantization?

    CERN Document Server

    Galapon, E A

    2002-01-01

    We raise the possibility of developing a theory of constructing quantum dynamical observables independent from quantization and deriving classical dynamical observables from pure quantum mechanical consideration. We do so by giving a detailed quantum mechanical derivation of the classical time of arrival at arbitrary arrival points for a particle in one dimension.

  4. Quantized layer growth at liquid-crystal surfaces

    DEFF Research Database (Denmark)

    Ocko, B. M.; Braslau, A.; Pershan, P. S.

    1986-01-01

    of the specular reflectivity is consistent with a sinusoidal density modulation, starting at the surface and terminating abruptly, after an integral number of bilayers. As the transition is approached the number of layers increases in quantized steps from zero to five before the bulk undergoes a first...

  5. Statistical amplitude scale estimation for quantization-based watermarking

    NARCIS (Netherlands)

    Shterev, I.D.; Lagendijk, I.L.; Heusdens, R.

    2004-01-01

    Quantization-based watermarking schemes are vulnerable to amplitude scaling. Therefore the scaling factor has to be accounted for either at the encoder, or at the decoder, prior to watermark decoding. In this paper we derive the marginal probability density model for the watermarked and attacked dat

  6. Classification of Boar Sperm Head Images using Learning Vector Quantization

    NARCIS (Netherlands)

    Biehl, Michael; Pasma, Piter; Pijl, Marten; Sánchez, Lidia; Petkov, Nicolai; Verleysen, Michel

    2006-01-01

    We apply Learning Vector Quantization (LVQ) in automated boar semen quality assessment. The classification of single boar sperm heads into healthy (normal) and non-normal ones is based on grey-scale microscopic images only. Sample data was classified by veterinary experts and is used for training a

  7. The Mathematics of Divergence Based Online Learning in Vector Quantization

    NARCIS (Netherlands)

    Villmann, Thomas; Haase, Sven; Schleif, Frank-Michael; Hammer, Barbara; Biehl, Michael

    2010-01-01

    We propose the utilization of divergences in gradient descent learning of supervised and unsupervised vector quantization as an alternative for the squared Euclidean distance. The approach is based on the determination of the Fréchet-derivatives for the divergences, wich can be immediately plugged i

  8. An axiomatic approach to soft learning vector quantization and clustering.

    Science.gov (United States)

    Karayiannis, N B

    1999-01-01

    This paper presents an axiomatic approach to soft learning vector quantization (LVQ) and clustering based on reformulation. The reformulation of the fuzzy c-means (FCM) algorithm provides the basis for reformulating entropy-constrained fuzzy clustering (ECFC) algorithms. This analysis indicates that minimization of admissible reformulation functions using gradient descent leads to a broad variety of soft learning vector quantization and clustering algorithms. According to the proposed approach, the development of specific algorithms reduces to the selection of a generator function. Linear generator functions lead to the FCM and fuzzy learning vector quantization (FLVQ) algorithms while exponential generator functions lead to ECFC and entropy-constrained learning vector quantization (ECLVQ) algorithms. The reformulation of LVQ and clustering algorithms also provides the basis for developing uncertainty measures that can identify feature vectors equidistant from all prototypes. These measures are employed by a procedure developed to make soft LVQ and clustering algorithms capable of identifying outliers in the data set. This procedure is evaluated by testing the algorithms generated by linear and exponential generator functions on speech data.

  9. Quantization of edge currents for continuous magnetic operators

    CERN Document Server

    Kellendonk, J

    2003-01-01

    For a magnetic Hamiltonian on a half-plane given as the sum of the Landau operator with Dirichlet boundary conditions and a random potential, a quantization theorem for the edge currents is proven. This shows that the concept of edge channels also makes sense in presence of disorder. Moreover, gaussian bounds on the heat kernel and its covariant derivatives are obtained.

  10. A Superfield Formalism of osp(1,2) Covariant Quantization

    CERN Document Server

    Lavrov, P M

    2001-01-01

    We propose a superfield description of osp(1,2) covariant quantization by extending the set of admissibility conditions for the quantum action. We realize a superfield form of the generating equations, specify the vacuum functional and obtain the corresponding transformations of extended BRST symmetry.

  11. Superfield formulation of the lagrangian BRST quantization method

    CERN Document Server

    Lavrov, P M; Reshetnyak, A A

    1995-01-01

    Lagragian quantization rules for general gauge theories are proposed on a basis of a superfield formulation of the standard BRST symmetry. Independence of the S-matrix on a choice of the gauge is proved. The Ward identities in terms of superfields are derived.

  12. Degradation due to quantization noise in radio astronomy phased arrays

    NARCIS (Netherlands)

    Kokkeler, A.B.J.; Fridman, P.; Ardenne, van A.

    2001-01-01

    In this paper, a model is develped for determining the probability distribution of the output of a digital ader in case of 2-, 3- and 4-level quantization before summation. This probability distribution is then used to determine the efficiency of a system which determines the total power of the sign

  13. Inflation via Black Holes with Quantized Area Spectrum

    OpenAIRE

    Rador, Tonguç

    2002-01-01

    I present a very simplistic toy model for the inflationary paradigm where the size of the universe undergoes a period of exponential growth. The basic assumption I make use of is that black holes might have a quantized area (mass) spectrum with a stable ground state and that the universe has started with a tightly packed collection of these objects alone.

  14. Geometric quantization of mechanical systems with time-dependent parameters

    CERN Document Server

    Giachetta, G; Sardanashvily, G

    2001-01-01

    The momentum phase space of a mechanical system with classical parameters is a fiber bundle over a space of parameters. We provide its fiberwise geometric quantization. A Hamiltonian of such a system is affine in the temporal derivative of parameter functions that leads to the geometric Berry phactor phenomena.

  15. FAST TRACK COMMUNICATION: Quantization over boson operator spaces

    Science.gov (United States)

    Prosen, Tomaž; Seligman, Thomas H.

    2010-10-01

    The framework of third quantization—canonical quantization in the Liouville space—is developed for open many-body bosonic systems. We show how to diagonalize the quantum Liouvillean for an arbitrary quadratic n-boson Hamiltonian with arbitrary linear Lindblad couplings to the baths and, as an example, explicitly work out a general case of a single boson.

  16. Path integral quantization of scalar fluctuations above a kink

    CERN Document Server

    Alexandre, Jean

    2007-01-01

    We quantize scalar fluctuations in 1+1 dimensions above a classical background kink. The properties of the effective action for the corresponding classical field are studied with an exact functional method, alternative to exact Wilsonian renormalization, where the running parameter is a bare mass, and the regulator of the quantum theory is fixed.

  17. Learning dynamics and robustness of vector quantization and neural gas

    NARCIS (Netherlands)

    Witoelar, Aree; Biehl, Michael; Ghosh, Anarta; Hammer, Barbara

    Various alternatives have been developed to improve the winner-takes-all (WTA) mechanism in vector quantization, including the neural gas (NG). However, the behavior of these algorithms including their learning dynamics, robustness with respect to initialization, asymptotic results. etc. has only

  18. Biometric Quantization through Detection Rate Optimized Bit Allocation

    NARCIS (Netherlands)

    Chen, C.; Veldhuis, R.N.J.; Kevenaar, T.A.M.; Akkermans, A.H.M.

    2009-01-01

    Extracting binary strings from real-valued biometric templates is a fundamental step in many biometric template protection systems, such as fuzzy commitment, fuzzy extractor, secure sketch, and helper data systems. Previous work has been focusing on the design of optimal quantization and coding for

  19. Local mesh quantized extrema patterns for image retrieval.

    Science.gov (United States)

    Koteswara Rao, L; Venkata Rao, D; Reddy, L Pratap

    2016-01-01

    In this paper, we propose a new feature descriptor, named local mesh quantized extrema patterns (LMeQEP) for image indexing and retrieval. The standard local quantized patterns collect the spatial relationship in the form of larger or deeper texture pattern based on the relative variations in the gray values of center pixel and its neighbors. Directional local extrema patterns explore the directional information in 0°, 90°, 45° and 135° for a pixel positioned at the center. A mesh structure is created from a quantized extrema to derive significant textural information. Initially, the directional quantized data from the mesh structure is extracted to form LMeQEP of given image. Then, RGB color histogram is built and integrated with the LMeQEP to enhance the performance of the system. In order to test the impact of proposed method, experimentation is done with bench mark image repositories such as MIT VisTex and Corel-1k. Avg. retrieval rate and avg. retrieval precision are considered as the evaluation metrics to record the performance level. The results from experiments show a considerable improvement when compared to other recent techniques in the image retrieval.

  20. Effect of threshold quantization in opportunistic splitting algorithm

    KAUST Repository

    Nam, Haewoon

    2011-12-01

    This paper discusses algorithms to find the optimal threshold and also investigates the impact of threshold quantization on the scheduling outage performance of the opportunistic splitting scheduling algorithm. Since this algorithm aims at finding the user with the highest channel quality within the minimal number of mini-slots by adjusting the threshold every mini-slot, optimizing the threshold is of paramount importance. Hence, in this paper we first discuss how to compute the optimal threshold along with two tight approximations for the optimal threshold. Closed-form expressions are provided for those approximations for simple calculations. Then, we consider linear quantization of the threshold to take the limited number of bits for signaling messages in practical systems into consideration. Due to the limited granularity for the quantized threshold value, an irreducible scheduling outage floor is observed. The numerical results show that the two approximations offer lower scheduling outage probability floors compared to the conventional algorithm when the threshold is quantized. © 2006 IEEE.

  1. Scattering and conductance quantization in three-dimensional metal nanocontacts

    DEFF Research Database (Denmark)

    Brandbyge, Mads; Jacobsen, Karsten Wedel; Nørskov, Jens Kehlet

    1997-01-01

    The transmission through three-dimensional nanocontacts is calculated in the presence of localized scattering centers and boundary scattering using a coupled-channel recursion method. Simple confining potentials are used to investigate how robust the observation of quantized conductance is with r...

  2. Short-Message Quantize-Forward Network Coding

    CERN Document Server

    Kramer, Gerhard

    2011-01-01

    Compression via quantization and hashing lets relays form distributed "multi-output" nodes of a multi-input, multi-output (MIMO) system. Recent work shows that quantize-forward (QF) with long-message encoding and decoding achieves the same reliable rates as short-message compress-forward (CF). It is shown that short-message QF with backward or pipelined (sliding-window) decoding also achieve the same rates for a single-relay channel. The price paid is a more restrictive quantization that degrades performance for slow-fading channels with outage. For many relays and sources, short-message QF with backward decoding achieves the same rates as long-message QF, although again with a more restrictive quantization. Several practical advantages of short-message encoding are pointed out, e.g., reduced delay (enabling streaming) and simplified modulation (without requiring additional hashing). Furthermore, short-message encoding lets relays use decode-forward (DF) if their channel quality is good, and therefore enables...

  3. Integer and Half-Integer Quantization Conditions in Quantum Mechanics

    Institute of Scientific and Technical Information of China (English)

    DUAN Yi-Shi; JIA Duo-Jie

    2001-01-01

    The integer and half-integer quantization conditions are found in quantum mechanics based on the topological structure of symmetry group of the singlet and spinor wavefunction. The internal symmetry of the physical system is shown to be sufficient to determine the topological structure in quantum mechanics without taking int account the dynamical details about the interaction.

  4. Quantization and Quantum-Like Phenomena: A Number Amplitude Approach

    Science.gov (United States)

    Robinson, T. R.; Haven, E.

    2015-12-01

    Historically, quantization has meant turning the dynamical variables of classical mechanics that are represented by numbers into their corresponding operators. Thus the relationships between classical variables determine the relationships between the corresponding quantum mechanical operators. Here, we take a radically different approach to this conventional quantization procedure. Our approach does not rely on any relations based on classical Hamiltonian or Lagrangian mechanics nor on any canonical quantization relations, nor even on any preconceptions of particle trajectories in space and time. Instead we examine the symmetry properties of certain Hermitian operators with respect to phase changes. This introduces harmonic operators that can be identified with a variety of cyclic systems, from clocks to quantum fields. These operators are shown to have the characteristics of creation and annihilation operators that constitute the primitive fields of quantum field theory. Such an approach not only allows us to recover the Hamiltonian equations of classical mechanics and the Schrödinger wave equation from the fundamental quantization relations, but also, by freeing the quantum formalism from any physical connotation, makes it more directly applicable to non-physical, so-called quantum-like systems. Over the past decade or so, there has been a rapid growth of interest in such applications. These include, the use of the Schrödinger equation in finance, second quantization and the number operator in social interactions, population dynamics and financial trading, and quantum probability models in cognitive processes and decision-making. In this paper we try to look beyond physical analogies to provide a foundational underpinning of such applications.

  5. Generalized noise terms for the quantized fluctuational electrodynamics

    Science.gov (United States)

    Partanen, Mikko; Häyrynen, Teppo; Tulkki, Jukka; Oksanen, Jani

    2017-03-01

    The quantization of optical fields in vacuum has been known for decades, but extending the field quantization to lossy and dispersive media in nonequilibrium conditions has proven to be complicated due to the position-dependent electric and magnetic responses of the media. In fact, consistent position-dependent quantum models for the photon number in resonant structures have only been formulated very recently and only for dielectric media. Here we present a general position-dependent quantized fluctuational electrodynamics (QFED) formalism that extends the consistent field quantization to describe the photon number also in the presence of magnetic field-matter interactions. It is shown that the magnetic fluctuations provide an additional degree of freedom in media where the magnetic coupling to the field is prominent. Therefore, the field quantization requires an additional independent noise operator that is commuting with the conventional bosonic noise operator describing the polarization current fluctuations in dielectric media. In addition to allowing the detailed description of field fluctuations, our methods provide practical tools for modeling optical energy transfer and the formation of thermal balance in general dielectric and magnetic nanodevices. We use QFED to investigate the magnetic properties of microcavity systems to demonstrate an example geometry in which it is possible to probe fields arising from the electric and magnetic source terms. We show that, as a consequence of the magnetic Purcell effect, the tuning of the position of an emitter layer placed inside a vacuum cavity can make the emissivity of a magnetic emitter to exceed the emissivity of a corresponding electric emitter.

  6. In search of a new initialization of K-means clustering for color quantization

    Science.gov (United States)

    Frackiewicz, Mariusz; Palus, Henryk

    2015-12-01

    Color quantization is still an important auxiliary operation in the processing of color images. The K-means clustering (KM), used to quantize the color, requires an appropriate initialization. In this paper, we propose a combined KM method that use to initialize the results of well-known quantization algorithms such as Wu's, NeuQuant (NQ) and Neural Gas (NG). This approach, assessed by three quality indices: PSNR, ΔE and ΔM, improves the results. Experimental results of such combined quantization indicate that the deterministic Wu+KM and random NG+KM approaches leading to the best quantized images.

  7. Quantization of electromagnetic field and analysis of Purcell effect based on formalism of scattering matrix

    Science.gov (United States)

    Kaliteevski, M. A.; Gubaydullin, A. R.; Ivanov, K. A.; Mazlin, V. A.

    2016-09-01

    We have developed a rigorous self-consistent approach for the quantization of electromagnetic field in inhomogeneous structures. The approach is based on utilization of the scattering matrix of the system. Instead of the use of standard periodic Born-Karman boundary conditions, we use the quantization condition implying equating eigenvalues of the scattering matrix (S-matrix) of the system to unity (S-quantization). In the trivial case of uniform medium boundary condition for S-quantization is nothing but periodic boundary condition. S-quantization allows calculating modification of the spontaneous emission rate for arbitrary inhomogeneous structure and direction of the emitted radiation. S-quantization solves the long-standing problem coupled to normalization of the quasi-stationary electromagnetic modes. Examples of application of S-quantization for the calculation of spontaneous emission rate for the cases of Bragg reflector and microcavity are demonstrated.

  8. Design of 1.5 bit quantization correlator in satellite navigation software receiver

    Institute of Scientific and Technical Information of China (English)

    Hongwei Zhou; Tian Jin; Fangyao L

    2016-01-01

    Currently, 1 bit or 2 bit signal quantization is widely used in satelite navigation software receivers. The bit-wise paralel algorithm has been proposed for 1 bit and 2 bit signal quantization, which performs correlation with high efficiency. In order to improve the performance of the correlator, this paper proposes a new 1.5 bit quantization method. Theoreti-cal analyses are made from the aspects of complexity and quantization loss, and performance comparison between 1.5 bit quantization correlator and traditional correlators is dis-cussed. The results show that the 1.5 bit quantization algo-rithm can save about 30 percent complexity under similar quantization loss, reduce more than 0.5 dB signal noise ratio (SNR) loss under similar complexity. It shows great perform-ance improvement for correlators of satelite navigation soft-ware receivers.

  9. Dimension Reduction Quantization of LSP Parameters Based on Compressed Sensing%基于压缩感知的线谱对参数降维量化算法

    Institute of Scientific and Technical Information of China (English)

    肖强; 陈亮; 朱涛; 黄建军

    2011-01-01

    To achieve good reconstruction speech quality in very low bit rate speech codecs, an efficient dimension reduction quantization acheme for linear spectrum pair (LSP) parameters was proposed based on compressed sensing. In the encoder, the LSP parameters extracted from consecutive speech frames are shaped into a high dimensional vector, and then the dimension of the vector is reduced by CS to produce a measurement vector, the measurements are quantized using the split vector quantizer. In the decoder, according to the quantized measurements, the original LSP vector is reconstructed by the orthogonal matching pursuit method. Experimental results show that the scheme is more efficient than that of conventional matrix quantization scheme and DCT based dimension reduction quantization scheme, the average spectral distortion reduction of up to 0.23dB and 0.13dB is achieved respectively. Informal subjective listening test shows that the reconstructed speech has moderate intelligibility and naturalness, it is observed that the degradation in speech quality is tolerable and with low codebook storage requirements.%为实现高质量的极低速语音编码,提出一种基于压缩感知理论的线谱对(LSP)参数降维量化算法.编码端利用压缩感知理论对超帧LSP高维矢量进行降维处理,将原始LSP参数投影到低维空间,得到低维测量值,然后采用分裂矢量量化算法对测量值进行量化;解码端以量化后的测量值为已知条件,利用正交匹配追踪算法重构出原始LSP高维矢量.实验结果表明,本算法相对低速语音编码中的矩阵量化方案,平均谱失真降低了0.23dB,相对基于DCT变换的降维量化方案,平均谱失真降低了0.13dB.这种先降维再量化的思想可以大幅减少编码所需的比特数及码本存储复杂度,有效降低语音编码速率,并且合成语音可懂度、自然度较高,音质虽有所失真,但基本上感觉不到明显的听觉质量下降.

  10. Fractional flux quantization in loops of unconventional superconductors

    Energy Technology Data Exchange (ETDEWEB)

    Loder, Florian; Kampf, Arno P.; Kopp, Thilo [Center for Electronic Correlations and Magnetism, University of Augsburg (Germany)

    2013-07-01

    The magnetic flux threading a conventional superconducting ring is typically quantized in units of Φ{sub 0} = hc/2e. The factor 2 in the denominator of Φ{sub 0} originates from the existence of two different types of pairing states with minima of the free energy at even and odd multiples of Φ{sub 0}. Here we show that spatially modulated pairing states exist with energy minima at fractional flux values, in particular at multiples of Φ{sub 0}/2. In such states condensates with different center-of-mass momenta of the Cooper pairs coexist. The proposed mechanism for fractional flux quantization is discussed in the context of cuprate superconductors, where hc/4e flux periodicities as well as uniaxially modulated superconducting states were observed.

  11. Blind and readable image watermarking using wavelet tree quantization

    Institute of Scientific and Technical Information of China (English)

    HU Yuping; YU Shengsheng; ZHOU JingLi; SHI Lei

    2004-01-01

    A blind and readable image watermarking scheme using wavelet tree quantization is proposed. In order to increase the algorithm robustness and ensure the watermark integrity,error correction coding techniques are used to encode the embedded watermark. In the watermark embedding process, the wavelet coefficients of the host image are grouped into wavelet trees and each watermark bit is embedded by using two trees. The trees are so quantized that they exhibit a large enough statistical difference, which will later be used for watermark extraction. The experimental results show that the proposed algorithm is effective and robust to common image processing operations and some geometric operations such as JPEG compression,JPEG2000 compression, filtering, Gaussian noise attack, and row-column removal. It is demonstrated that the proposed technique is practical.

  12. Quantized Fields in a Nonlinear Dielectric Medium A Microscopic Approach

    CERN Document Server

    Hillery, M; Hillery, Mark; Mlodinow, Leonard

    1997-01-01

    Theories which have been used to describe the quantized electromagnetic field interacting with a nonlinear dielectric medium are either phenomenological or derived by quantizing the macroscopic Maxwell equations. Here we take a different approach and derive a Hamiltonian describing interacting fields from one which contains both field and matter degrees of freedom. The medium is modelled as a collection of two-level atoms, and these interact with the electromagnetic field. The atoms are grouped into effective spins and the Holstein- Primakoff representation of the spin operators is used to expand them in one over the total spin. When the lowest-order term is combined with the free atomic and field Hamiltonians, a theory of noninteracting polaritons results. When higher-order terms are expressed in terms of polariton operators, standard nonlinear optical interactions emerge.

  13. An optimal adaptive quantization index modulation watermarking algorithm

    Institute of Scientific and Technical Information of China (English)

    Shaomin Zhu; Jianming Liu

    2009-01-01

    A novel adaptive watermarking algorithm in discrete wavelet transform (DWT) based on quantization index modulation (QIM) technique is presented. The host image is decomposed into wavelet subbands, and then the approximation subband is divided into non-overlapping small embedding blocks. The secret watermark bit is embedded into singular value vector of each embedding block by applying QIM. To improve the invisibility and robustness of watermarking system, the quantization step for each embedding block is set by combining statistical model with particle swarm optimization (PSO) algorithm. The experimental results show that the proposed algorithm not only preserves the high perceptual quality, but also effectively stands against joint photographic experts group (JPEG) compression, low-pass filtering, noise addition, scaling, and cropping attacks, etc. The comparison analysis demonstrates that our scheme has better performance than the previously reported watermarking algorithms.

  14. Quantization Audio Watermarking with Optimal Scaling on Wavelet Coefficients

    CERN Document Server

    Chen, S -T; Tu, S -Y

    2011-01-01

    In recent years, discrete wavelet transform (DWT) provides an useful platform for digital information hiding and copyright protection. Many DWT-based algorithms for this aim are proposed. The performance of these algorithms is in term of signal-to-noise ratio (SNR) and bit-error-rate (BER) which are used to measure the quality and the robustness of an embedded audio. However, there is a tradeoff relationship between the embedded-audio quality and robustness. The tradeoff relationship is a signal processing problem in the wavelet domain. To solve this problem, this study presents an optimization-based scaling scheme using optimal multi-coefficients quantization in the wavelet domain. Firstly, the multi-coefficients quantization technique is rewritten as an equation with arbitrary scaling on DWT coefficients and set SNR to be a performance index. Then, a functional connecting the equation and the performance index is derived. Secondly, Lagrange Principle is used to obtain the optimal solution. Thirdly, the scal...

  15. Features of multiphoton-stimulated bremsstrahlung in a quantized field

    Science.gov (United States)

    Burenkov, Ivan A.; Tikhonova, Olga V.

    2010-12-01

    The process of absorption and emission of external field quanta by a free electron during the scattering on a potential centre is investigated in the case of interaction with a quantized electromagnetic field. The analytical expression for differential cross-sections and probabilities of different multiphoton channels are obtained. We demonstrate that in the case of a non-classical 'squeezed vacuum' initial field state the probability for the electron to absorb a large number of photons appears to be larger by several orders of magnitude in comparison to the classical field and leads to the formation of the high-energy plateau in the electron energy spectrum. The generalization of the Marcuse effect to the case of the quantized field is worked out. The total probability of energy absorption by electron from the non-classical light is analysed.

  16. Features of multiphoton-stimulated bremsstrahlung in a quantized field

    Energy Technology Data Exchange (ETDEWEB)

    Burenkov, Ivan A; Tikhonova, Olga V, E-mail: ovtikhonova@mail.r [Institute of Nuclear Physics, Moscow State University, Leninskie Gory 1, Moscow, 119991 (Russian Federation)

    2010-12-14

    The process of absorption and emission of external field quanta by a free electron during the scattering on a potential centre is investigated in the case of interaction with a quantized electromagnetic field. The analytical expression for differential cross-sections and probabilities of different multiphoton channels are obtained. We demonstrate that in the case of a non-classical 'squeezed vacuum' initial field state the probability for the electron to absorb a large number of photons appears to be larger by several orders of magnitude in comparison to the classical field and leads to the formation of the high-energy plateau in the electron energy spectrum. The generalization of the Marcuse effect to the case of the quantized field is worked out. The total probability of energy absorption by electron from the non-classical light is analysed.

  17. Semiclassical quantization using Bogomolny's quantum surface of section

    CERN Document Server

    Haggerty, M R

    1995-01-01

    The efficacy and accuracy of Bogomolny's method of the quantum surface of section is evaluated by applying it to the quantization of the motion of a particle in a smooth 2-D potential. This method defines a transfer operator T in terms of classical trajectories of one Poincar\\'e crossing; knowledge of T provides information about the eigenstates of the quantum system. By using a more robust quantization criterion than the one proposed by Bogomolny, we are able to locate more than five hundred quantum states in both the regular and the chaotic regimes---in most cases unambiguously---and see no reason that the spectra could not be continued indefinitely. The errors of the predictions are comparable in the two regimes, and roughly constant for increasing excitation, but grow as a fraction of the (shrinking) mean level spacing. We also show computed surface of section wavefunctions, and present other theoretical and practical results related to the technique.

  18. Conformal Loop quantization of gravity coupled to the standard model

    Science.gov (United States)

    Pullin, Jorge; Gambini, Rodolfo

    2016-03-01

    We consider a local conformal invariant coupling of the standard model to gravity free of any dimensional parameter. The theory is formulated in order to have a quantized version that admits a spin network description at the kinematical level like that of loop quantum gravity. The Gauss constraint, the diffeomorphism constraint and the conformal constraint are automatically satisfied and the standard inner product of the spin-network basis still holds. The resulting theory has resemblances with the Bars-Steinhardt-Turok local conformal theory, except it admits a canonical quantization in terms of loops. By considering a gauge fixed version of the theory we show that the Standard model coupled to gravity is recovered and the Higgs boson acquires mass. This in turn induces via the standard mechanism masses for massive bosons, baryons and leptons.

  19. Noncommutative spectral geometry, algebra doubling, and the seeds of quantization

    Science.gov (United States)

    Sakellariadou, Mairi; Stabile, Antonio; Vitiello, Giuseppe

    2011-08-01

    A physical interpretation of the two-sheeted space, the most fundamental ingredient of noncommutative spectral geometry proposed by Connes as an approach to unification, is presented. It is shown that the doubling of the algebra is related to dissipation and to the gauge structure of the theory, the gauge field acting as a reservoir for the matter field. In a regime of completely deterministic dynamics, dissipation appears to play a key role in the quantization of the theory, according to the ’t Hooft’s conjecture. It is thus argued that the noncommutative spectral geometry classical construction carries the seeds of quantization, implicit in its feature of the doubling of the algebra.

  20. Precanonical Quantization and the Schr\\"odinger Wave Functional Revisited

    CERN Document Server

    Kanatchikov, I V

    2011-01-01

    We address the long-standing issue of the relation between the Schr\\"odinger functional representation in quantum field theory and the approach of precanonical field quantization which requires neither a distinguished time variable nor infinite-dimensional spaces of field configurations. The functional Schr\\"odinger equation is derived in the limiting case \\varkappa \\rightarrow \\delta(0) from the Dirac-like covariant generalization of the Schr\\"odinger equation within the precanonical quantization approach, where the constant \\varkappa of the dimension of the inverse spatial volume naturally appears on dimensional grounds. An explicit expression of the Schr\\"odinger wave functional as a continuous product of precanonical wave functions on the finite-dimensional covariant configuration space of the field and space-time variables is obtained.

  1. Finite-dimensional Hilbert space and frame quantization

    Energy Technology Data Exchange (ETDEWEB)

    Cotfas, Nicolae [Faculty of Physics, University of Bucharest, PO Box 76-54, Post Office 76, Bucharest (Romania); Gazeau, Jean Pierre [Laboratoire APC, Universite Paris Diderot, 10, rue A Domon et L Duquet, 75205 Paris Cedex 13 (France); Vourdas, Apostol, E-mail: ncotfas@yahoo.com, E-mail: gazeau@apc.univ-paris7.fr, E-mail: A.Vourdas@bradford.ac.uk [Department of Computing, University of Bradford, Bradford BD7 1DP (United Kingdom)

    2011-04-29

    The quantum observables used in the case of quantum systems with finite-dimensional Hilbert space are defined either algebraically in terms of an orthonormal basis and discrete Fourier transformation or by using a continuous system of coherent states. We present an alternative approach to these important quantum systems based on the finite frame quantization. Finite systems of coherent states, usually called finite tight frames, can be defined in a natural way in the case of finite quantum systems. Novel examples of such tight frames are presented. The quantum observables used in our approach are obtained by starting from certain classical observables described by functions defined on the discrete phase space corresponding to the system. They are obtained by using a finite frame and a Klauder-Berezin-Toeplitz-type quantization. Semi-classical aspects of tight frames are studied through lower symbols of basic classical observables.

  2. Experimental evidence for a two-dimensional quantized Hall insulator

    Science.gov (United States)

    Hilke, M.; Shahar, D.; Song, S. H.; Tsui, D. C.; Xie, Y. H.; Monroe, Don

    1998-10-01

    The general theoretical definition of an insulator is a material in which the conductivity vanishes at the absolute zero of temperature. In classical insulators, such as materials with a band gap, vanishing conductivities lead to diverging resistivities. But other insulators can show more complex behaviour, particularly in the presence of a high magnetic field, where different components of the resistivity tensor can display different behaviours: the magnetoresistance diverges as the temperature approaches absolute zero, but the transverse (Hall) resistance remains finite. Such a system is known as a Hall insulator. Here we report experimental evidence for a quantized Hall insulator in a two-dimensional electron system-confined in a semiconductor quantum well. The Hall resistance is quantized in the quantum unit of resistance h/e2, where h is Planck's constant and e the electronic charge. At low fields, the sample reverts to being a normal Hall insulator.

  3. Wavelet/scalar quantization compression standard for fingerprint images

    Energy Technology Data Exchange (ETDEWEB)

    Brislawn, C.M.

    1996-06-12

    US Federal Bureau of Investigation (FBI) has recently formulated a national standard for digitization and compression of gray-scale fingerprint images. Fingerprints are scanned at a spatial resolution of 500 dots per inch, with 8 bits of gray-scale resolution. The compression algorithm for the resulting digital images is based on adaptive uniform scalar quantization of a discrete wavelet transform subband decomposition (wavelet/scalar quantization method). The FBI standard produces archival-quality images at compression ratios of around 15 to 1 and will allow the current database of paper fingerprint cards to be replaced by digital imagery. The compression standard specifies a class of potential encoders and a universal decoder with sufficient generality to reconstruct compressed images produced by any compliant encoder, allowing flexibility for future improvements in encoder technology. A compliance testing program is also being implemented to ensure high standards of image quality and interchangeability of data between different implementations.

  4. Precise quantization of anomalous Hall effect near zero magnetic field

    Energy Technology Data Exchange (ETDEWEB)

    Bestwick, A. J. [Stanford Univ., Stanford, CA (United States); SLAC National Accelerator Lab., Menlo Park, CA (United States); Fox, E. J. [Stanford Univ., Stanford, CA (United States); SLAC National Accelerator Lab., Menlo Park, CA (United States); Kou, Xufeng [Univ. of California, Los Angeles, CA (United States); Pan, Lei [Univ. of California, Los Angeles, CA (United States); Wang, Kang L. [Univ. of California, Los Angeles, CA (United States); Goldhaber-Gordon, D. [Stanford Univ., Stanford, CA (United States); SLAC National Accelerator Lab., Menlo Park, CA (United States)

    2015-05-04

    In this study, we report a nearly ideal quantum anomalous Hall effect in a three-dimensional topological insulator thin film with ferromagnetic doping. Near zero applied magnetic field we measure exact quantization in the Hall resistance to within a part per 10,000 and a longitudinal resistivity under 1 Ω per square, with chiral edge transport explicitly confirmed by nonlocal measurements. Deviations from this behavior are found to be caused by thermally activated carriers, as indicated by an Arrhenius law temperature dependence. Using the deviations as a thermometer, we demonstrate an unexpected magnetocaloric effect and use it to reach near-perfect quantization by cooling the sample below the dilution refrigerator base temperature in a process approximating adiabatic demagnetization refrigeration.

  5. Compression of Ultrasonic NDT Image by Wavelet Based Local Quantization

    Science.gov (United States)

    Cheng, W.; Li, L. Q.; Tsukada, K.; Hanasaki, K.

    2004-02-01

    Compression on ultrasonic image that is always corrupted by noise will cause `over-smoothness' or much distortion. To solve this problem to meet the need of real time inspection and tele-inspection, a compression method based on Discrete Wavelet Transform (DWT) that can also suppress the noise without losing much flaw-relevant information, is presented in this work. Exploiting the multi-resolution and interscale correlation property of DWT, a simple way named DWCs classification, is introduced first to classify detail wavelet coefficients (DWCs) as dominated by noise, signal or bi-effected. A better denoising can be realized by selective thresholding DWCs. While in `Local quantization', different quantization strategies are applied to the DWCs according to their classification and the local image property. It allocates the bit rate more efficiently to the DWCs thus achieve a higher compression rate. Meanwhile, the decompressed image shows the effects of noise suppressed and flaw characters preserved.

  6. Belief Propagation based MIMO Detection Operating on Quantized Channel Output

    CERN Document Server

    Mezghani, Amine

    2010-01-01

    In multiple-antenna communications, as bandwidth and modulation order increase, system components must work with demanding tolerances. In particular, high resolution and high sampling rate analog-to-digital converters (ADCs) are often prohibitively challenging to design. Therefore ADCs for such applications should be low-resolution. This paper provides new insights into the problem of optimal signal detection based on quantized received signals for multiple-input multiple-output (MIMO) channels. It capitalizes on previous works which extensively analyzed the unquantized linear vector channel using graphical inference methods. In particular, a "loopy" belief propagation-like (BP) MIMO detection algorithm, operating on quantized data with low complexity, is proposed. In addition, we study the impact of finite receiver resolution in fading channels in the large-system limit by means of a state evolution analysis of the BP algorithm, which refers to the limit where the number of transmit and receive antennas go t...

  7. F-theory with zeroth-quantized ghosts

    CERN Document Server

    Siegel, W

    2016-01-01

    F-theory in its most general sense should be a theory defined on a worldvolume of higher dimension than the worldsheet, that reproduces string results perturbatively but includes nonperturbative supergravity solutions at the first-quantized level. This implies that in some sense it should contain the same oscillator modes as the string but an enlarged set of zero-modes. In this paper we concentrate on the higher-dimensional properties of the worldvolume (rather than those of spacetime): "Ghost" dimensions are added to the worldvolume, as might be expected in a "zeroth-quantized" approach to the constraints on its higher bosonic dimensions, by adding equal numbers of bosonic and fermionic dimensions to the worldsheet.

  8. Schroedinger Equation and the Quantization of Celestial Systems

    Directory of Open Access Journals (Sweden)

    Smarandache F.

    2006-04-01

    Full Text Available In the present article, we argue that it is possible to generalize Schroedinger equation to describe quantization of celestial systems. While this hypothesis has been described by some authors, including Nottale, here we argue that such a macroquantization was formed by topological superfluid vortice. We also provide derivation of Schroedinger equation from Gross-Pitaevskii-Ginzburg equation, which supports this superfluid dynamics interpretation.

  9. Radial Quantization for Conformal Field Theories on the Lattice

    CERN Document Server

    Brower, Richard C; Neuberger, Herbert

    2012-01-01

    We consider radial quantization for conformal quantum field theory with a lattice regulator. A Euclidean field theory on $\\mathbb R^D$ is mapped to a cylindrical manifold, $\\mathbb R\\times \\mathbb S^{D-1}$, whose length is logarithmic in scale separation. To test the approach, we apply this to the 3D Ising model and compute $\\eta$ for the first $Z_2$ odd primary operator.

  10. Background-independent quantization and the uncertainty principle

    Energy Technology Data Exchange (ETDEWEB)

    Hossain, Golam Mortuza; Husain, Viqar; Seahra, Sanjeev S, E-mail: ghossain@unb.c, E-mail: vhusain@unb.c, E-mail: sseahra@unb.c [Department of Mathematics and Statistics, University of New Brunswick, Fredericton, NB E3B 5A3 (Canada)

    2010-08-21

    It is shown that polymer quantization leads to a modified uncertainty principle similar to that motivated by string theory and non-commutative geometry. When applied to quantum field theory on general background spacetimes, corrections to the uncertainty principle acquire a metric dependence. For Friedmann-Robertson-Walker cosmology this translates to a scale factor dependence which gives a large effect in the early Universe.

  11. Polymer quantization and the saddle point approximation of partition functions

    Science.gov (United States)

    Morales-Técotl, Hugo A.; Orozco-Borunda, Daniel H.; Rastgoo, Saeed

    2015-11-01

    The saddle point approximation of the path integral partition functions is an important way of deriving the thermodynamical properties of black holes. However, there are certain black hole models and some mathematically analog mechanical models for which this method cannot be applied directly. This is due to the fact that their action evaluated on a classical solution is not finite and its first variation does not vanish for all consistent boundary conditions. These problems can be dealt with by adding a counterterm to the classical action, which is a solution of the corresponding Hamilton-Jacobi equation. In this work we study the effects of polymer quantization on a mechanical model presenting the aforementioned difficulties and contrast it with the above counterterm method. This type of quantization for mechanical models is motivated by the loop quantization of gravity, which is known to play a role in the thermodynamics of black hole systems. The model we consider is a nonrelativistic particle in an inverse square potential, and we analyze two polarizations of the polymer quantization in which either the position or the momentum is discrete. In the former case, Thiemann's regularization is applied to represent the inverse power potential, but we still need to incorporate the Hamilton-Jacobi counterterm, which is now modified by polymer corrections. In the latter, momentum discrete case, however, such regularization could not be implemented. Yet, remarkably, owing to the fact that the position is bounded, we do not need a Hamilton-Jacobi counterterm in order to have a well-defined saddle point approximation. Further developments and extensions are commented upon in the discussion.

  12. Loop quantum gravity and black hole entropy quantization

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    Using the spin networks and the asymptotic quasinormal mode frequencies of black holes given by loop quantum gravity,the minimum horizon area gap is obtained.Then the quantum area spectrum of black holes is derived and the black hole entropy is a realized quantization.The results show that the black hole entropy given by loop quantum gravity is in full accord with the Bekenstein-Hawking entropy with a suitable Immirzi.

  13. Loop quantum gravity and black hole entropy quantization

    Institute of Scientific and Technical Information of China (English)

    LI ChuanAn; JIANG JiJian; SU JiuQing

    2009-01-01

    Using the spin networks and the asymptotic quasinormal mode frequencies of black holes given by loop quantum gravity, the minimum horizon area gap is obtained. Then the quantum area spectrum of black holes is derived and the black hole entropy is a realized quantization. The results show that the black hole entropy given by loop quantum gravity is in full accord with the Bekenstein-Hawking entropy with a suitable Immirzi.

  14. Lazy global feedbacks for quantized nonlinear event systems

    CERN Document Server

    Jerg, Stefan

    2012-01-01

    We consider nonlinear event systems with quantized state information and design a globally stabilizing controller from which only the minimal required number of control value changes along the feedback trajectory to a given initial condition is transmitted to the plant. In addition, we present a non-optimal heuristic approach which might reduce the number of control value changes and requires a lower computational effort. The constructions are illustrated by two numerical examples.

  15. Degenerate Plebanski Sector and its Spin Foam Quantization

    CERN Document Server

    Alexandrov, Sergei

    2012-01-01

    We show that the degenerate sector of Spin(4) Plebanski formulation of four-dimensional gravity is exactly solvable and describes covariantly embedded SU(2) BF theory. This fact provides its spin foam quantization and allows to test various approaches of imposing the simplicity constraints. Our analysis suggests a unique method of imposing the constraints which leads to a consistent and well defined spin foam model.

  16. Torus as phase space: Weyl quantization, dequantization, and Wigner formalism

    Energy Technology Data Exchange (ETDEWEB)

    Ligabò, Marilena, E-mail: marilena.ligabo@uniba.it [Dipartimento di Matematica, Università di Bari, I-70125 Bari (Italy)

    2016-08-15

    The Weyl quantization of classical observables on the torus (as phase space) without regularity assumptions is explicitly computed. The equivalence class of symbols yielding the same Weyl operator is characterized. The Heisenberg equation for the dynamics of general quantum observables is written through the Moyal brackets on the torus and the support of the Wigner transform is characterized. Finally, a dequantization procedure is introduced that applies, for instance, to the Pauli matrices. As a result we obtain the corresponding classical symbols.

  17. Noncommutative spectral geometry, dissipation and the origin of quantization

    CERN Document Server

    Sakellariadou, Mairi; Vitiello, Giuseppe

    2012-01-01

    We present a physical interpretation of the doubling of the algebra, which is the basic ingredient of the noncommutative spectral geometry, developed by Connes and collaborators as an approach to unification. We discuss its connection to dissipation and to the gauge structure of the theory. We then argue, following 't Hooft's conjecture, that noncommutative spectral geometry classical construction carries implicit in its feature of the doubling of the algebra the seeds of quantization.

  18. Superfield Hamiltonian quantization in terms of quantum antibrackets

    Science.gov (United States)

    Batalin, Igor A.; Lavrov, Peter M.

    2016-04-01

    We develop a new version of the superfield Hamiltonian quantization. The main new feature is that the BRST-BFV charge and the gauge fixing Fermion are introduced on equal footing within the sigma model approach, which provides for the actual use of the quantum/derived antibrackets. We study in detail the generating equations for the quantum antibrackets and their primed counterparts. We discuss the finite quantum anticanonical transformations generated by the quantum antibracket.

  19. Superfield Hamiltonian quantization in terms of quantum antibrackets

    CERN Document Server

    Batalin, Igor A

    2016-01-01

    We develop a new version of the superfield Hamiltonian quantization. The main new feature is that the BRST-BFV charge and the gauge fixing Fermion are introduced on equal footing within the sigma model approach, which provides for the actual use of the quantum/derived antibrackets. We study in detail the generating equations for the quantum antibrackets and their primed counterparts. We discuss the finite quantum anticanonical transformations generated by the quantum antibracket.

  20. Covariant Quantization of the Brink-Schwarz Superparticle

    CERN Document Server

    Grassi, P A; Porrati, Massimo

    2001-01-01

    The quantization of the Brink-Schwarz-Casalbuoni superparticle is performed in an explicitly covariant way using the antibracket formalism. Since an infinite number of ghost fields are required, within a suitable off-shell twistor-like formalism, we are able to fix the gauge of each ghost sector without modifying the physical content of the theory. The computation reveals that the antibracket cohomology contains only the physical degrees of freedom.