bluuebunny/crossref_metadata_2025 huggingface dataset:
LEARNING LOGIC RULES FOR THE TOWER OF KNOWLEDGE USING MARKOV LOGIC NETWORKS
Authors: XU MAI , PETROU MARIA , LU JIANHUA
Published: March 2011

In this paper, we propose a novel logic-rule learning approach for the Tower of Knowledge (ToK) architecture, based on Markov logic networks, for scene interpretation. This approach is in the spirit of the recently proposed Markov logic networks for machine learning. Its purpose is to learn the soft-constraint logic rules for labeling the components of a scene. In our approach, FOIL (First Order Inductive Learner) is applied to learn the logic rules for MLN and then gradient ascent search is utilized to compute weights attached to each rule for softening the rules. This approach also benefits from the architecture of ToK, in reasoning whether a component in a scene has the right characteristics in order to fulfil the functions a label implies, from the logic point of view. One significant advantage of the proposed approach, rather than the previous versions of ToK, is its automatic logic learning capability such that the manual insertion of logic rules is not necessary. Experiments of labeling the identified components in buildings, for building scene interpretation, illustrate the promise of this approach.
INCREMENTAL CLUSTERING USING INFORMATION BOTTLENECK THEORY
Authors: LIU YONGLI , OUYANG YUANXIN , XIONG ZHANG
Published: March 2011

Document clustering is one of the most effective techniques to organize documents in an unsupervised manner. In this paper, an Incremental method for document Clustering based on Information Bottleneck theory (ICIB) is presented. The ICIB is designed to improve the accuracy and efficiency of document clustering, and resolve the issue that an arbitrary choice of document similarity measure could produce an inaccurate clustering result. In our approach, document similarity is calculated using information bottleneck theory and documents are grouped incrementally. A first document is selected randomly and classified as one cluster, then each remaining document is processed incrementally according to the mutual information loss introduced by the merger of the document and each existing cluster. If the minimum value of mutual information loss is below a certain threshold, the document will be added to its closest cluster; otherwise it will be classified as a new cluster. The incremental clustering process is low-precision and order-dependent, which cannot guarantee accurate clustering results. Therefore, an improved sequential clustering algorithm (SIB) is proposed to adjust the intermediate clustering results. In order to test the effectiveness of ICIB method, ten independent document subsets are constructed based on the 20NewsGroup and Reuters-21578 corpora. Experimental results show that our ICIB method achieves higher accuracy and time performance than K-Means, AIB and SIB algorithms.
NAVIGALA: AN ORIGINAL SYMBOL CLASSIFIER BASED ON NAVIGATION THROUGH A GALOIS LATTICE
Authors: VISANI M. , BERTET K. , OGIER J.-M.
Published: March 2011

This paper deals with a supervised classification method, using Galois Lattices based on a navigation-based strategy. Coming from the field of data mining techniques, most literature on the subject using Galois lattices relies on selection-based strategies, which consists of selecting/choosing the concepts which encode the most relevant information from the huge amount of available data. Generally, the classification step is then processed by a classical classifier such as the k-nearest neighbors rule or the Bayesian classifier. Opposed to these selection-based strategies are navigation-based approaches which perform the classification stage by navigating through the complete lattice (similar to the navigation in a classification tree), without applying any selection operation. Our approach, named Navigala, proposes an original navigation-based approach for supervised classification, applied in the context of noisy symbol recognition. Based on a state of the art dealing with Galois Lattices classification based methods, including a comparison between possible selection and navigation strategies, this paper proposes a description of NAVIGALA and its implementation in the context of symbol recognition. Some objective quantitative and qualitative evaluations of the approach are proposed, in order to highlight the relevance of the method.
TRACKING MULTIPLE PERSONS BASED ON ATTRIBUTED RELATIONAL GRAPH
Authors: WAN QIN , WANG YAONAN , YU HONGSHAN , YUAN XIAOFANG , LU JUAN
Published: March 2011

The appearance model is very effective in tracking multiple persons. The main difficulty in tracking persons is to represent appearance reliably and effectively, especially in the presence of occlusions. In this paper, an effective Attributed Relational Graph (ARG) based tracking algorithm is presented to track multiple persons even under occlusions. The appearance of each person is expressed by an ARG model which not only combines color feature with spatial information but also illustrates the relations among body parts. The similarity of ARG models is computed to build a matching matrix in consecutive frames. Four tracking situations are determined according to the matching matrix. In addition, to track persons under occlusions, probabilistic relaxation labeling in the ARG models of body parts is deduced to label occluded persons optimally. Experimental validation of the proposed tracking method is verified and presented on indoor and outdoor sequences.
AN ADAPTIVE INTERPOLATION SCHEME BASED ON ITERATIVE BACK-PROJECTION AND HVS-BASED QUALITY METRIC FOR IMAGE SEQUENCES
Authors: LIN GUO-SHIANG , LAI MIN-KUAN
Published: March 2011

In this paper, we propose an adaptive interpolation scheme based on iterative back-projection and human visual system based quality metric for image sequences. Initial estimates of each up-sampled image can be generated individually by using subpixel interpolation and subpixel motion estimation in the spatial and temporal domains respectively. Then, based on the initial estimates and edge information, up-sampled images are derived by using an iterative back-projection technique and a quality metric based on the human visual system. After fusing the up-sampled images into a final version, a low-pass filter is applied as a post-processing step to reduce the effect of blocking artifacts in each reconstructed up-sampled image. Our experimental results demonstrate that, in terms of PSNR (Peak Signal-to-Noise Ratio) and NQM (Noise Quality Metric), the proposed scheme outperforms four existing methods.
A SURVEY OF CLUSTERING ENSEMBLE ALGORITHMS
Authors: VEGA-PONS SANDRO , RUIZ-SHULCLOPER JOSÉ
Published: March 2011

Cluster ensemble has proved to be a good alternative when facing cluster analysis problems. It consists of generating a set of clusterings from the same dataset and combining them into a final clustering. The goal of this combination process is to improve the quality of individual data clusterings. Due to the increasing appearance of new methods, their promising results and the great number of applications, we consider that it is necessary to make a critical analysis of the existing techniques and future projections. This paper presents an overview of clustering ensemble methods that can be very useful for the community of clustering practitioners. The characteristics of several methods are discussed, which may help in the selection of the most appropriate one to solve a problem at hand. We also present a taxonomy of these techniques and illustrate some important applications.
BUILDING RECOGNITION BASED ON INDIRECT LOCATION OF PLANAR LANDMARK IN FLIR IMAGE SEQUENCES
Authors: WANG DENGWEI , ZHANG TIANXU , WAN MEIJUN , SHI WENJUN , WEI LONGSHENG , YANG XIAOYU
Published: March 2011

A novel method is proposed to deal with the problem of building recognition in forward-looking infrared (FLIR) image sequences. Two computational models are deduced in this paper: one is the perspective transformation model, through which an image is transformed perspectively from downward-looking state to forward-looking state; the other is the indirect location model, through which the position of a building is computed in an FLIR image. In addition, in order to illustrate the application scope of our method, the error analysis is presented. The proposed approach is validated by extensive experiments, with images taken in different weather conditions, seasons and at different times. Superior recognition results were obtained on three FLIR image sequences we collected.
DENOISING OF THREE-DIMENSIONAL DATA CUBE USING BIVARIATE WAVELET SHRINKING
Authors: CHEN GUANGYI , BUI TIEN D. , KRZYZAK ADAM
Published: March 2011

The denoising of a natural signal/image corrupted by Gaussian white noise is a classical problem in signal/image processing. However, it is still in its infancy to denoise high dimensional data. In this paper, we extended Sendur and Selesnick's bivariate wavelet thresholding from two-dimensional (2D) image denoising to three-dimensional (3D) data cube denoising. Our study shows that bivariate wavelet thresholding is still valid for 3D data cubes. Experimental results show that bivariate wavelet thresholding on 3D data cube is better than performing 2D bivariate wavelet thresholding on every spectral band separately, VisuShrink, and Chen and Zhu's 3-scale denoising.
CLASSIFYING FACIAL EXPRESSIONS USING LEVEL SET METHOD BASED LIP CONTOUR DETECTION AND MULTI-CLASS SUPPORT VECTOR MACHINES
Authors: SOHAIL ABU SAYEED MD. , BHATTACHARYA PRABIR
Published: March 2011

This paper describes a fully automated computer vision system for detection and classification of the seven basic facial expressions using Multi-Class Support Vector Machine (SVM). Facial expressions are communicated by subtle changes in one or more discrete features such as tightening of the lips, raising the eyebrows, opening and closing of eyes or certain combination of them, which can be identified through monitoring the changes in muscle movements (Action Units), located around the regions of mouth, eyes and eyebrows. For classifying facial expressions, an analytic representation of face with 15 feature points has been used that provides visual observation of the discrete features responsible for the seven basic facial expressions. Feature points from the region of mouth are detected by segmenting the lip contour applying a variational formulation of the level set method. A multidetector approach of facial feature point detection is utilized for identifying the feature-points from the regions of eyes, eyebrows and nose. Feature vectors composed of 15 features are then obtained with respect to the average representation of neutral face and are used to train a Multiclass SVM classifier. The proposed method has been tested over two different facial expression image databases and the average successful recognition rates of 92.04% and 86.33% have been achieved.
AN IMPROVED LOCALLY LINEAR EMBEDDING FOR SPARSE DATA SETS
Authors: WEN YING , HE LIANGHUA
Published: March 2011

Locally linear embedding is often invalid for sparse data sets because locally linear embedding simply takes the reconstruction weights obtained from the data space as the weights of the embedding space. This paper proposes an improved method for sparse data sets, a united locally linear embedding, to make the reconstruction more robust to sparse data sets. In the proposed method, the neighborhood correlation matrix presenting the position information of the points constructed from the embedding space is added to the correlation matrix in the original space, thus the reconstruction weights can be adjusted. As the reconstruction weights adjusted gradually, the position information of sparse points can also be changed continually and the local geometry of the data manifolds in the embedding space can be well preserved. Experimental results on both synthetic and real-world data show that the proposed approach is very robust against sparse data sets.
A NOVEL VALIDITY INDEX FOR THE SUBTRACTIVE CLUSTERING ALGORITHM
Authors: SHIEH HORNG-LIN , KUO CHENG-CHIEN
Published: March 2011

This paper proposes a new validity index for the subtractive clustering (SC) algorithm. The subtractive clustering algorithm proposed by Chiu is an effective and simple method for identifying the cluster centers of sampling data based on the concept of a density function. The SC algorithm continually produces the cluster centers until the final potential compared with the original is less than a predefined threshold. The procedure is terminated when there are only a few data points around the most recent cluster. The choice of the threshold is an important factor affecting the clustering results: if it is too large, then too few data points will be accepted as cluster centers; if it is too small, then too many cluster centers will be generated. In this paper, a modified SC algorithm for data clustering based on a cluster validity index is proposed to obtain the optimal number of clusters. Six examples show that the proposed index achieves better performance results than other cluster validities do.
IMPROVING INCREMENTAL WRAPPER-BASED SUBSET SELECTION VIA REPLACEMENT AND EARLY STOPPING
Authors: BERMEJO PABLO , GAMEZ JOSE A. , PUERTA JOSE M.
Published: March 2011

This paper deals with the problem of feature subset selection in classification-oriented datasets with a (very) large number of attributes. In such datasets complex classical wrapper approaches become intractable due to the high number of wrapper evaluations to be carried out. One way to alleviate this problem is to use the so-called filter-wrapper approach or Incremental Wrapper-based Subset Selection (IWSS), which consists of the construction of a ranking among the predictive attributes by using a filter measure, and then a wrapper approach is used by following the rank. In this way the number of wrapper evaluations is linear on the number of predictive attributes. In this paper we present two contributions to the IWSS approach. The first one is related with obtaining more compact subsets, and enables not only the addition of new attributes but also their interchange with some of those already included in the selected subset. Our second contribution, termed early stopping, sets an adaptive threshold on the number of attributes in the ranking to be considered. The advantages of these new approaches are analyzed both theoretically and experimentally. The results over a set of 12 high-dimensional datasets corroborate the success of our proposals.
AN IMPROVED FEATURE VOCABULARY BASED METHOD FOR IMAGE CATEGORIZATION
Authors: SHIH FRANK Y. , SHEPPARD ALEXANDER
Published: March 2011

The bags of feature and feature vocabulary based approaches have been presented for image categorization due to their simplicity and competitive performance. Some modified versions have been subsequently proposed, incorporating the methods such as adapted vocabularies, fast indexing, and Gaussian mixture models. In this paper, we propose an improvement of replacing the Harris-affine detection method by a random sampling procedure together with an increased number of sample points. Experimental results show that this new method improves categorization accuracy on a five-category problem using the Caltech-4 dataset. It is concluded that random sampling produces higher attainable point density and better categorization performance.
LOSSLESS SECRET SHARING SCHEME WITH HIGH QUALITY SHARES BASED ON VQ-COMPRESSED IMAGES
Authors: CHANG CHIN-CHEN , CHEN KUO-NAN , HUYNH NGOC-TU
Published: March 2011

In this paper, we propose an efficient secret sharing scheme without pixel expansion. The scheme first uses the VQ-compression method to compress a secret image. This allows senders to share a larger secret image than other methods. Moreover, the proposed method also allows participants to reconstruct a lossless secret image. The generated shadows are meaningful with high quality, so the image does not attract any suspicion from attackers. Because the scheme uses XOR operation during the construction and revealing phases, it is suitable for secret sharing applications.
A WORD POSITION-RELATED LDA MODEL
Authors: ZHAI LIDONG , DING ZHAOYUN , JIA YAN , ZHOU BIN
Published: March 2011

LDA (Latent Dirichlet Allocation) proposed by Blei is a generative probabilistic model of a corpus, where documents are represented as random mixtures over latent topics, and each topic is characterized by a distribution over words, but not the attributes of word positions of every document in the corpus. In this paper, a Word Position-Related LDA Model is proposed taking into account the attributes of word positions of every document in the corpus, where each word is characterized by a distribution over word positions. At the same time, the precision of the topic-word's interpretability is improved by integrating the distribution of the word-position and the appropriate word degree, taking into account the different word degree in the different word positions. Finally, a new method, a size-aware word intrusion method is proposed to improve the ability of the topic-word's interpretability. Experimental results on the NIPS corpus show that the Word Position-Related LDA Model can improve the precision of the topic-word's interpretability. And the average improvement of the precision in the topic-word's interpretability is about 9.67%. Also, the size-aware word intrusion method can interpret the topic-word's semantic information more comprehensively and more effectively through comparing the different experimental data.
BIN-PACKING ALGORITHMS FOR PERIODIC TASK SCHEDULING
Authors: ZHU ZHILIN , SUI JINXUE , YANG LI
Published: March 2011

CAN (Controller Area Network) operation observes event triggering standards, it is widely applied in real-time distributional control system of the automobile electronic control system, satellite control system, medical equipment's electronic control system as well as the textile equipment and so on. As the extension of offline bin-packing problem, periodic task scheduling has many important applications in real-time distributed systems. For time triggered CAN control systems, two strategies to determine the basic cycle (BC) of TTCAN are presented. Next-fit algorithm, next-fit descending algorithm, best-fit algorithm and best-fit descending algorithm are proposed to construct periodic task scheduling tables. Time complexity and worst-case asymptotic performance ratio of these algorithms are analyzed, and the experimental results indicate that NFA algorithm is not worse than NFDA algorithm, BFA is also not worse than BFDA algorithm, four algorithms have the advantage over the typical one-dimensional bin-packing algorithm.
EXISTENCE AND APPROXIMATION OF A (REGULARIZED) OLDROYD-B MODEL
Authors: BARRETT JOHN W. , BOYAVAL SÉBASTIEN
Published: March 2011

We consider the finite element approximation of the Oldroyd-B system of equations, which models a dilute polymeric fluid, in a bounded domain [Formula: see text], d = 2 or 3, subject to no flow boundary conditions. Our schemes are based on approximating the pressure and the symmetric conformation tensor by either (a) piecewise constants or (b) continuous piecewise linears. In case (a) the velocity field is approximated by continuous piecewise quadratics or a reduced version, where the tangential component on each simplicial edge (d = 2) or face (d = 3) is linear. In case (b) the velocity field is approximated by continuous piecewise quadratics or the mini-element. We show that both of these types of schemes satisfy a free energy bound, which involves the logarithm of the conformation tensor, without any constraint on the time step for the backward Euler-type time discretization. This extends the results of Boyaval et al. (Free-energy-dissipative schemes for the Oldroyd-B model, ESAIM: Math. Model. Numer. Anal.43 (2009) 523–561) on this free energy bound. There a piecewise constant approximation of the conformation tensor was necessary to treat the advection term in the stress equation, and a restriction on the time step, based on the initial data, was required to ensure that the approximation to the conformation tensor remained positive definite. Furthermore, for our approximation (b) in the presence of an additional dissipative term in the stress equation and a cut-off on the conformation tensor on certain terms in the system, similar to those introduced in Barrett and Süli (Existence of global weak solutions to dumbbell models for dilute polymers with microscopic cut-off, Math. Models Methods Appl. Sci.18 (2008) 935–971) for the microscopic–macroscopic finitely extensible nonlinear elastic model of a dilute polymeric fluid, we show (subsequence) convergence, as the spatial and temporal discretization parameters tend to zero, toward global-in-time weak solutions of this regularized Oldroyd-B system. Hence, we prove existence of global-in-time weak solutions to this regularized model. Moreover, in the case d = 2 carry out this convergence in the absence of cut-offs, but with a time step restriction dependent on the spatial discretization parameter, and hence show existence of a global-in-time weak solution to the Oldroyd-B system with an additional dissipative term in the stress equation.
AN EVOLUTIONARY ELASTOPLASTIC PLATE MODEL DERIVED VIA Γ-CONVERGENCE
Authors: LIERO MATTHIAS , MIELKE ALEXANDER
Published: March 2011

This paper is devoted to dimension reduction for linearized elastoplasticity in the rate-independent case. The reference configuration of the three-dimensional elastoplastic body has a two-dimensional middle surface and a positive but small thickness. Under suitable scalings we derive a limiting model for the case in which the thickness of the plate tends to 0. This model contains membrane and plate deformations (linear Kirchhoff–Love plate), which are coupled via plastic strains. We establish strong convergence of the solutions in the natural energy space. The analysis uses an abstract Γ-convergence theory for rate-independent evolutionary systems that is based on the notion of energetic solutions. This concept is formulated via an energy-storage functional and a dissipation functional, such that energetic solutions are defined in terms of a stability condition and an energy balance. The Mosco convergence of the quadratic energy-storage functional follows the arguments of the elastic case. To handle the evolutionary situation the interplay with the dissipation functional is controlled by cancellation properties for Mosco-convergent quadratic energies.
A Case Study of Illegal Insider Trading — The Scandal of Vultures' Insider Trading
Authors: Huang Yu Chuan , Chan Shu Hui
Published: March 2011

The purpose of this paper is to look at the duration of the four-month period before the window dressing of Power Quotient International Co., LTD. (PQI) annual report between 2004 and 2005 was disclosed. The vultures sold 6,373,000 shares of PQI's stock based on the illegally obtained insider information. The empirical results indicate that the vultures' selling did not make PQI's stock price go down during insider period, but PQI's stock price did appear to rise and significantly exceeded the non-insider period. However, the proportion of vultures' selling is negatively correlated with the changes in PQI's stock price. The effect of vultures' selling is indifferent from the effect of non-vultures' selling during insider period. Market liquidity is also affected unfavorably in the presence of vultures' trading. Additionally, the newspaper's reports on PQI's positive or negative news significantly influence the investment decision of investors in Taiwan, and significantly influence the PQI's price changes and market liquidity.
Oil Shocks and Equity Returns: An Empirical Analysis of the US Transportation Sector
Authors: Mohanty Sunil K. , Nandha Mohan
Published: March 2011

The main purpose of this paper is to investigate the relation between oil price movements and stock returns in US transportation companies. We estimate oil price risk exposures of the US oil transport sector at the firm level as well as at the industry level over November 1999 to February 2008 period using the Fama–French–Carhart's (1997) four-factor asset pricing model augmented with oil price and interest rate factors. Overall, the results of our study suggest that oil price exposures of firms in the US transportation sector vary across firms and over time. The varying effects of oil shocks on stock returns may be attributed to several factors such as differences among firms' cost structure, financial policies, diversification activities, and hedging strategies.
MAXIMAL IDEALS IN PREADDITIVE CATEGORIES AND SEMILOCAL CATEGORIES
Authors: FACCHINI ALBERTO , PERONE MARCO
Published: March 2011

The first aim of this article is to study maximal ideals of a preadditive category [Formula: see text]. Maximal ideals, which do not exist in general for arbitrary preadditive categories, are associated to a maximal ideal of the endomorphism ring of an object and always exist when the category is semilocal. If [Formula: see text] is additive and semilocal, any skeleton [Formula: see text] of [Formula: see text] is a Krull monoid and we are able to characterize the essential valuations of [Formula: see text] and provide some natural divisor homomorphisms and divisor theories of [Formula: see text].
LIFTING THEOREMS FOR TENSOR FUNCTORS ON MODULE CATEGORIES
Authors: WISBAUER ROBERT
Published: March 2011

Any (co)ring R is an endofunctor with (co)multiplication on the category of abelian groups. These notions were generalized to monads and comonads on arbitrary categories. Starting around 1970 with papers by Beck, Barr and others a rich theory of the interplay between such endofunctors was elaborated based on distributive laws between them and Applegate's lifting theorem of functors between categories to related (co)module categories. Curiously enough some of these results were not noticed by researchers in module theory and thus notions like entwining structures and smash products between algebras and coalgebras were introduced (in the nineties) without being aware that these are special cases of the more general theory.

The purpose of this survey is to explain several of these notions and recent results from general category theory in the language of elementary module theory focusing on functors between module categories given by tensoring with a bimodule. This provides a simple and systematic approach to smash products, wreath products, corings and rings over corings (C-rings). We also highlight the relevance of the Yang–Baxter equation for the structures on the threefold tensor product of algebras or coalgebras (see 3.6).
CHAINS OF PROJECTIVE MODULES
Authors: FUCHS LÁSZLÓ , RANGASWAMY KULUMANI M.
Published: March 2011

We consider modules over commutative rings. We are looking for sufficient conditions for a continuous well-ordered ascending chain of projective modules that are pure in their union to have a projective union. First, we deal with countable chains without restriction on the sizes of the modules; in this case no extra hypothesis is needed provided R is an integral domain or ℵ0-noetherian (Theorem 1.3); in the latter case, the theorem covers pure-projectvity as well. We also consider chains of longer lengths over an integral domain. We establish a condition (in terms of a slightly modified κ+-freeness) for the projectivity of the union provided that the links of the chain are ≤ κ-generated and the length of the chain is κ+ for an infinite cardinal κ (Theorem 1.4). Our theorems generalize several results in the literature.
THE FACTOR RING OF A QUASI-BAER RING BY ITS PRIME RADICAL
Authors: BIRKENMEIER GARY F. , KIM JIN YONG , PARK JAE KEOL
Published: March 2011

The quasi-Baer condition of R/P(R) is investigated when R is a quasi-Baer ring, where P(R) is the prime radical of R. We provide an example of quasi-Baer ring R such that R/P(R) is not quasi-Baer. However, when P(R) is nilpotent, we prove that if R is a quasi-Baer (resp., Baer) ring, then R/P(R) is quasi-Baer (resp., Baer). Examples which illustrate and delimit the results of this paper are provided.
GMRA-BASED CONSTRUCTION OF FRAMELETS IN REDUCING SUBSPACES OF L2(ℝd)
Authors: LI YUN-ZHANG , ZHOU FENG-YING
Published: March 2011

This paper develops GMRA-based construction procedures of Parseval framelets in the setting of reducing subspaces of L2(ℝd). A unitary extension principle is established; in particular, for a general expansive matrix A with | det A| = 2, an explicit construction of Parseval framelets is obtained. Some examples are also provided to illustrate the generality of our theory.
ALGORITHM OF ε-SVR BASED ON A LARGE-SCALE SAMPLE SET: STEP-BY-STEP SEARCH
Authors: ZENG SHAOHUA , TANG Y. Y. , WEI YAN , WANG YONG
Published: March 2011

In view of the support vectors of ε-SVR that are not distributed in the ε belt and only located on the outskirts of the ε belt, a novel algorithm to construct ε-SVR of a large-scale training sample set is proposed in this paper. It computes firstly the ε-SVR hyper-plane of a small training sample set and the distances d of all samples to the hyper-plane, then deletes the samples not in field ε ≤ d ≤ d max and searches SVs gradually in the scope ε ≤ d ≤ d max , and trains step-by-step the final ε-SVR. Finally, it analyzes the time complexity of the algorithm, and verifies its convergence in the theory and tests its efficiency by the simulation.
FEATURE EXTRACTION OF SEWER PIPE DEFECTS USING WAVELET TRANSFORM AND CO-OCCURRENCE MATRIX
Authors: YANG MING-DER , SU TUNG-CHING , PAN NANG-FEI , LIU PEI
Published: March 2011

In general, the sewer inspection usually employs a great number of CCTV images to discover sewer failures by human interpretation. A computer-aided program remains to be developed due to human's fatigue and subjectivity. To enhance the efficiency of sewer inspection, this paper attends to apply artificial intelligence to extract the failure features of the sewer systems that is demonstrated on the sewer system in the eastern Taichung City, Taiwan. Wavelet transform and gray-level co-occurrence matrix, which have been widely applied in many texture analyses, are adopted in this research to generate extracted features, which are the most valuable information in pattern recognition of failures on CCTV images. Wavelet transform is capable of dividing an image into four sub-images including approximation sub-image, horizontal detail sub-image, vertical detail sub-image, and diagonal detail sub-image. The co-occurrence matrices of horizontal orientation, vertical orientation, and 45° and 135° orientations, respectively, were calculated for the horizontal, vertical, and diagonal detail sub-images. Subsequently, the features including angular second moment, entropy, contrast, homogeneity, dissimilarity, correlation, and cluster tendency, can be obtained from the co-occurrence matrices. However, redundant features either decrease the accuracy of texture description or increase the difficulty of pattern recognition. Thus, the correlations of the features are estimated to search the appropriate feature sets according to the correlation coefficients between the features. In addition, a discriminant analysis was used to evaluate the discriminability of the features for the pipe failure defection, and entropy, correlation, and cluster tendency were found to be the best features based on the discriminant accuracy through an error matrix analysis.
ECG SIGNAL CODING USING BIORTHOGONAL WAVELET-BASED BURROWS–WHEELER CODER
Authors: KUMARI R. SHANTHA SELVA , PRABHA R. SURIYA , SADASIVAM V.
Published: March 2011

Wavelets are the powerful tool for signal processing especially bio-signal processing. Wavelet transform is used to represent the signal to some other time frequency representation better suited for detecting and removing redundancies. In this paper, electrocardiogram (ECG) signal coding using biorthogonal wavelet-based Burrows–Wheeler Coder is discussed. Biorthogonal wavelet transform is used to decompose the ECG signal. Then the Burrows–Wheeler Coder is applied in order to compress the decomposed ECG signal. The Burrows–Wheeler Coder is the combination of Burrows–Wheeler Transformation (BWT), Move-to-Front (MTF) coder and Huffman coder. Compression Ratio (CR) and Percent Root mean square Difference (PRD) are used as performance measures. ECG signals/records from MIT-BIH arrhythmic database are used to evaluate the performance of this coder. This algorithm is tested with 25 different records from MIT-BIH arrhythmia database and obtained the average PRD as 0.0307% to 3.8706% for the average CR of 3.6362 : 1 to 280.48 : 1. For record 117, the CR of 8.1638 : 1 is achieved with PRD 0.1652%. This experimental results show that this coder outperforms other coders such as Djohn, EZW, SPIHT, Novel algorithm etc. that exist in the literature in terms of coding efficiency and computation.
REMOTE PREPARATION OF AN ARBITRARY TWO-PARTICLE PURE STATE VIA NONMAXIMALLY ENTANGLED STATES AND POSITIVE OPERATOR-VALUED MEASUREMENT
Authors: WANG DONG
Published: March 2011

A scheme for remotely preparing an arbitrary two-particle pure state is proposed by employing bipartite nonmaximally entangled states as quantum channels. During the preparation, two auxiliary particles and an optimal positive operator-valued measurement are introduced. The preparation of two-particle pure states can be remotely realized with certain success probability (SP). And the SP of our scheme is exactly worked out. It turns out that the SP depends inherently on the quantum channels employed beforehand. Furthermore, we find that, as far as two special ensembles of two-particle states are concerned, i.e. real and equatorial-like, the SP can be enhanced to quadruple.
QUANTUM SECURE DIRECT COMMUNICATION WITH A CONSTANT NUMBER OF EPR PAIRS
Authors: LU CHIN-YUNG , WANG SHIOU-AN , CHENG YUH-JIUH , KUO SY-YEN
Published: March 2011

In this paper, we propose a quantum secure direct communication (QSDC) protocol based on Einstein–Podolsky–Rosen (EPR) pairs. Previous QSDC protocols usually consume one EPR pair to transmit a single qubit. If Alice wants to transmit an n-bit message, she needs at least n/2 EPR pairs when a dense coding scheme is used. In our protocol, if both Alice and Bob preshare 2c + 1 EPR pairs with the trusted server, where c is a constant, Alice can transmit an arbitrary number of qubits to Bob. The 2c EPR pairs are used by Alice and Bob to authenticate each other and the remaining EPR pair is used to encode and decode the message qubit. Thus the total number of EPR pairs used for one communication is a constant no matter how many bits will be transmitted. It is not necessary to transmit EPR pairs before transmitting the secret message except for the preshared constant number of EPR pairs. This reduces both the utilization of the quantum channel and the risk. In addition, after the authentication, the server is not involved in the message transmission. Thus we can prevent the server from knowing the message.
SCHEME FOR IMPLEMENTING AN N-QUBIT CONTROLLED NOT GATE WITH SUPERCONDUCTING QUANTUM INTERFERENCE DEVICES IN CAVITY QED
Authors: FANG BAO-LONG , YANG ZHEN , YE LIU
Published: March 2011

We present a scheme for implementing a Toffoli gate. The superconducting quantum interference devices are coupled to a resonant cavity with nonidentical SQUID–cavity coupling constants. So only one interaction between SQUID and cavity is required, and a Toffoli gate can be obtained. The method can be generalized to the N-qubit case easily and the scheme is insensitive to systematic coupling error.
SECURITY OF MULTIPARTY QUANTUM SECRET SHARING WITH MULTIQUBIT GHZ STATES
Authors: WANG XIN-WEN , ZHANG DENG-YU , TANG SHI-QING , GAO FENG
Published: March 2011

We study the security of multiparty quantum secret sharing (QSS) with multiqubit Greenberger–Horne–Zeilinger states. We give a detailed proof that the original scheme of Xiao et al. [Phys. Rev. A69 (2004) 052307] is insecure against the interior attack (i.e. the participants' attack) which is the most serious threat for QSS protocols. Thereafter, an improvement of this QSS protocol is proposed.
EFFICIENT FAULT-TOLERANT QUANTUM SECRET SHARING OVER TWO COLLECTIVE-NOISE CHANNELS
Authors: DUAN XIAOJIAO , ZHOU RIFENG , LI XIHAN
Published: March 2011

Based on the quantum key distribution protocol [X. H. Li, F. G. Deng and H. Y. Zhou, Phys. Rev. A78 (2008) 022321], we proposed two efficient fault-tolerant quantum secret sharing schemes over two collective-noise channels, in which the sharers can establish a key with the sender only if all the sharers collaborate together. Noiseless subspaces are composed of two Bell states based on the hypothesis of collective noise and the spatial degree of freedom is introduced to insure the security. Although entangled states are used to encode the key bits, the sharers are only required to perform single-particle product operations or single-particle product measurement, making the schemes convenient with current technique. As there is no basis mismatch during the measurement, almost all of the samples can be used to share the key.
GENERATION OF THE N-QUBIT CLUSTER STATE IN THE ION TRAP SYSTEM VIA ADIABATIC EVOLUTION OF THE DARK STATE
Authors: CHENG GUANG-LING , ZHONG WEN-XUE , CHEN AI-XI
Published: March 2011

We present an alternative scheme for generating the N-qubit cluster state in the ion trap system. This scheme is based on adiabatic passage and thus is insensitive to the small fluctuations of the system parameters. During the process of evolution, quantum information transfer occurs only between the ions, and the collective vibrational mode remains in the vacuum state without excitation. Thus, the scheme is robust against phonon decoherence.
RELATIVISTIC EINSTEIN–PODOLSKY–ROSEN CORRELATIONS IN COSMIC STRING SPACE–TIME VIA FERMI–WALKER TRANSPORT
Authors: BAKKE KNUT , CARVALHO ALEXANDRE M. DE M. , FURTADO CLAUDIO
Published: March 2011

We present a geometric approach to study the relativistic EPR correlations in curved space–time background given by the application of the Fermi–Walker transport in the relativistic EPR states and show that its result has the same effect as the applications of successive infinitesimal Lorentz boosts in the relativistic EPR states. We also show that the expression for the Bell inequality due to the Fermi–Walker transport is equivalent to the expression demonstrated by Terashima and Ueda,20 where the degree of violation of the Bell inequality depends on the angle of the Wigner rotation. This geometrical approach for study of the relativistic EPR correlations is a promising formulation to investigate the EPR correlations in the general relativity background.
ON APPROXIMATE n-ARY DERIVATIONS
Authors: GORDJI M. ESHAGHI , KHODABAKHSH R. , KHODAEI H.
Published: March 2011

C. Park et al. proved the stability of homomorphisms and derivations in Banach algebras, Banach ternary algebras, C*-algebras, Lie C*-algebras and C*-ternary algebras. In this paper, we improve and generalize some results concerning derivations. We first introduce the following generalized Jensen functional equation [Formula: see text] and using fixed point methods, we prove the stability of n-ary derivations and n-ary Jordan derivations in n-ary Banach algebras. Secondly, we study this functional equation with *-n-ary derivations in C*-n-ary algebras.
ON THE RANDERS METRICS ON TWO-STEP HOMOGENEOUS NILMANIFOLDS OF DIMENSION FIVE
Authors: MOGHADDAM HAMID REZA SALIMI
Published: March 2011

In this paper we study the geometry of simply connected two-step nilpotent Lie groups of dimension five. We give the Levi–Civita connection, curvature tensor, sectional and scalar curvatures of these spaces and show that they have constant negative scalar curvature. Also we show that the only space which admits left-invariant Randers metric of Berwald type has three-dimensional center. In this case the explicit formula for computing flag curvature is obtained and it is shown that flag curvature and sectional curvature have the same sign.
UNCONSTRAINED HIGHER SPINS IN FOUR DIMENSIONS
Authors: BANDELLONI GIUSEPPE
Published: March 2011

The relativistic symmetric tensor fields are, in four dimensions, the right candidates to describe Higher Spin Fields. Their highest spin content is isolated with the aid of covariant conditions, discussed within a group theory framework, in which auxiliary fields remove the lower intrinsic angular momenta sectors. These conditions are embedded within a Lagrangian Quantum Field theory which describes an Higher Spin Field interacting with a Classical background. The model is invariant under a (B.R.S.) symmetric unconstrained tensor extension of the reparametrization symmetry, which include the Fang–Fronsdal algebra in a well defined limit. However, the symmetry setting reveals that the compensator field, which restore the Fang–Fronsdal symmetry of the free equations of motion, is in the existing in the framework and has a relevant geometrical meaning. The Ward identities coming from this symmetry are discussed. Our constraints give the result that the space of the invariant observables is restricted to the ones constructed with the Highest Spin Field content. The quantum extension of the symmetry reveals that no new anomaly is present. The role of the compensator field in this result is fundamental.
ON THE NONCOMMUTATIVE EIKONAL
Authors: ISIDRO J. M. , DE CÓRDOBA P. FERNÁNDEZ , RIVERA–REBOLLEDO J. M. , SANTANDER J. L. G.
Published: March 2011

We study the Eikonal approximation to quantum mechanics on the Moyal plane. Instead of using a star product, the analysis is carried out in terms of operator-valued wavefunctions depending on noncommuting, operator-valued coordinates.
CANONICAL FORM OF THE EVOLUTION OPERATOR OF A TIME-DEPENDENT HAMILTONIAN IN THE THREE LEVEL SYSTEM
Authors: FUJII KAZUYUKI
Published: March 2011

In this paper we study the evolution operator of a time-dependent Hamiltonian in the three level system. The evolution operator is based on SU(3) and its dimension is eight, so we obtain three complex Riccati differential equations interacting with one another (which have been obtained by Fujii and Oike) and two real phase equations. This is a canonical form of the evolution operator.
THE BRAUER GROUP OF DEL PEZZO SURFACES
Authors: CARTER ANDREA C.
Published: March 2011

Let S1 be a Del Pezzo surface of degree 1 over a number field k. We establish a criterion for the existence of a nontrivial element of order 5 in the Brauer group of S1 in terms of certain Galois-stable configurations of exceptional divisors on this surface.
modp CONGRUENCES FOR CUSP FORMS OF WEIGHT FOUR FOR Γ0(pN)
Authors: BARCAU MUGUREL , PAŞOL VICENŢIU
Published: March 2011

In [1], the authors prove a conjecture of Calegari and Stein regarding mod p congruences between cusp forms of weight four for Γ0(p) and the derivatives of cusp forms of weight two for the same congruence subgroup. In this paper, we investigate whether or not the result remains valid for cusp forms of level Np.
AN APPLICATION OF NESTERENKO'S DIMENSION ESTIMATE TO p-ADIC q-SERIES
Authors: BUNDSCHUH PETER , VÄÄNÄNEN KEIJO
Published: March 2011

Very recently, Nesterenko proved a p-adic analogue of his famous dimension estimate from 1985. The main aim of our present paper is to use this criterion to obtain lower bounds for the dimension of ℚ-vector spaces spanned by the values at certain rational points of p-adic solutions of a class of linear q-difference equations. For the application of Nesterenko's new estimate, we first need a p-adic analogue of Töpfer's results on entire solutions of such functional equations, and secondly, very precise evaluations of certain p-adic Schnirelman integrals.
ON THE NUMBER OF INTEGER POINTS ON THE ELLIPTIC CURVE y2 = x3 + Ax
Authors: DRAZIOTIS KONSTANTINOS A.
Published: March 2011

It is given an upper bound for the number of the integer points of the elliptic curve y2 = x3 + Ax (A ∈ ℤ) and a conjecture of Schmidt is proven for this family of elliptic curves.
ANOTHER LOOK AT GROSS–STARK UNITS OVER THE NUMBER FIELD ℚ
Authors: PARK JEEHOON
Published: March 2011

We provide another description of the Gross–Stark units over the rational field ℚ (studied in [B. Gross, p-Adic L-series at s = 0, J. Fac. Sci. Univ. Tokyo28(3) (1981) 979–994]) which is essentially a Gauss sum, using a p-adic multiplicative integral of the p-adic Kubota–Leopoldt distribution, and give a simplified proof of the Ferrero–Greenberg theorem (see [B. Ferrero and R. Greenberg, On the behavior of p-adic L-functions at s = 0, Invent. Math.50(1) (1978/79) 91–102]) for p-adic Hurwitz zeta functions. This is a precise analog for ℚ of Darmon–Dasgupta's work on elliptic units for real quadratic fields (see [H. Darmon and S. Dasgupta, Elliptic units for real quadratic fields, Ann. of Math. (2)163(1) (2006) 301–346]).
SETS WITH SEVERAL CENTERS OF SYMMETRY
Authors: FREIMAN GREGORY A. , STANCHESCU YONUTZ V.
Published: March 2011

Let A be a finite subset of the group ℤ2. Let C = {c0, c1,…,cs-1} be a finite set of s distinct points in the plane. For every 0 ≤ i ≤ s -1, we define Di = {a - a′ : a ∈ A, a′ ∈ A, a + a′ = 2ci} and Rs(A) = |D0 ∪ D1 ∪…∪ Ds-1|. In [1, 2], we found the maximal value of Rs(A) in cases s = 1, s = 2 and s = 3 and studied the structure of A assuming that R3(A) is equal or close to its maximal value. In this paper, we examine the case of s = 4 centers of symmetry and we find the maximal value of R4(A). Moreover, in cases when the maximal value is attained, we will describe the structure of extremal sets.
CUSP FORMS ON GSp(4) WITH SO(4)-PERIODS
Authors: FLICKER YUVAL Z.
Published: March 2011

The Saito–Kurokawa lifting of automorphic representations from PGL(2) to the projective symplectic group of similitudes PGSp(4) of genus 2 is studied using the Fourier summation formula (an instance of the "relative trace formula"), thus characterizing the image as the representations with a nonzero period for the special orthogonal group SO(4, E/F) associated to a quadratic extension E of the global base field F, and a nonzero Fourier coefficient for a generic character of the unipotent radical of the Siegel parabolic subgroup. The image is nongeneric and almost everywhere nontempered, violating a naive generalization of the Ramanujan conjecture. Technical advances here concern the development of the summation formula and matching of relative orbital integrals.
ON NUMBER FIELDS WITH NONTRIVIAL SUBFIELDS
Authors: WIDMER MARTIN
Published: March 2011

What is the probability for a number field of composite degree d to have a nontrivial subfield? As the reader might expect the answer heavily depends on the interpretation of probability. We show that if the fields are enumerated by the smallest height of their generators the probability is zero, at least if d > 6. This is in contrast to what one expects when the fields are enumerated by the discriminant. The main result of this paper is an estimate for the number of algebraic numbers of degree d = en and bounded height which generate a field that contains an unspecified subfield of degree e. If n > max {e2 + e, 10}, we get the correct asymptotics as the height tends to infinity.
THE ADDITIVE S-UNIT STRUCTURE OF QUADRATIC FIELDS
Authors: ZIEGLER VOLKER
Published: March 2011

We consider a variation of the unit sum number problem for quadratic fields and prove various results.
INDEPENDENCE OF HEEGNER POINTS FOR NONMAXIMAL ORDERS
Authors: ASTANEH-ASL ALI , DAGHIGH HASSAN
Published: March 2011

The independence of Heegner points associated to distinct imaginary quadratic fields has been shown by Rosen and Silverman. In this paper we show the independence of Heegner points associated to orders with the same conductor in distinct imaginary quadratic fields.
CUBIC SURFACES WITH A GALOIS INVARIANT PAIR OF STEINER TRIHEDRA
Authors: ELSENHANS ANDREAS-STEPHAN , JAHNEL JÖRG
Published: March 2011

We present a method to construct non-singular cubic surfaces over ℚ with a Galois invariant pair of Steiner trihedra. We start with cubic surfaces in a form generalizing that of Cayley and Salmon. For these, we develop an explicit version of Galois descent.
ON GENERATORS OF ARITHMETIC GROUPS OVER FUNCTION FIELDS
Authors: PAPIKIAN MIHRAN
Published: March 2011

Let F = 𝔽q(T) be the field of rational functions with 𝔽q-coefficients, and A = 𝔽q[T] be the subring of polynomials. Let D be a division quaternion algebra over F which is split at 1/T. For certain A-orders in D we find explicit finite sets generating their groups of units.