Directory of Open Access Journals (Sweden)
P. A. Shchinnikov
2017-01-01
Full Text Available The possibilities of operation of electric generators based on internal combustion engines with air cooling under conditions of cogeneration, when, along with the electricity, heat release in different embodiments is provided. Such facilities are usually realized on the basis of gasoline internal combustion engines (i.e. gasoline is used as a fuel. They can be used in the household, by professional builders, geologists, the military and rescuers in the area of emergencies and in areas with a lack of infrastructure. The basis of the facility is the gasoline generator Hitachi-2400 with an air-cooled power of 2.4 kW. The basic methodology for the study of microthermal power plants based on an air-cooled internal combustion engine which is based on balance equations is presented. The facility operation ensures the measurement of all temperatures and expenses of operating environments for determining heat flow in accordance with the proposed methodology. The specifications of heat exchangers for utilizing the heat of exhaust flue gases are presented. The energy diagram illustrating the useful effect of the application of various heat exchangers are plotted. Cogeneration possibilities of the facility are provided, firstly, by the release of heat with the air that cools a cylinder of the internal combustion engine, and, secondly, by the release of heat of hot water heated by utilizing the heat of the leaving flue gases, and, thirdly, in the calculated version, by the release of heat with air that is sequentially heated due to the cooling of the cylinder head and then by utilizing the heat of exhaust gases. It is demonstrated that the fuel heat utilization factor can be increased from 0.22 to 0.50–0.60, depending on the adopted technical solutions.
Institute of Scientific and Technical Information of China (English)
茹毅; 王飞
2012-01-01
热电厂的循环冷却水系统存在大量的低位热能。热泵系统具有将低位热能提升为高位热能的能力。本文即是根据山西某热电厂的节能改造方案介绍了利用吸收式热泵系统回收电厂冷凝余热用于集中供热的新技术;并对新型供热系统做出能效和经济性评价,认为新技术应用具有经济和环境的双重效益,有广阔发展前景。%There is a large number of low level heat energy in the circulating cooling water system of thermal power plant.Heat pump system has the ability to improve the heat energy level from low order into high order.This article introduced the new technology,application to central heating,of usage of absorption high temperature heat pump system for recycling waste heat of condensation which based on the energy-saving reform plan of one heat-power plant in Shanxi province.Based on the new central heating systems the energy efficiency and economic evaluation be giving in this paper.Through the analysis shows that the application of new technology has the double effect in economic efficiency and environmental protection that has broad prospects for development.
基于CD4046感应加热电源的研究设计%The research on induction heating power supply based on CD4046
Institute of Scientific and Technical Information of China (English)
袁倩; 刘平; 陈睿科
2016-01-01
为了解决传统感应加热电源开关损耗较高及功率因数较低的不良效果，本文设计出了一种以集成高速锁相环CD4046为核心的控制电路，该控制电路可以对逆变器进行实时频率跟踪，根据反馈信号做出合理的相位补偿，确保逆变器工作于弱感性状态，并在获得较高输入功率因数的同时实现开关零电压功能，实验结果表明该控制电路结构简单，工作性能稳定，在工业应用方面存在潜在价值。%In view of the disadvantages that there are higher switching loss and lower power factor in the traditional induction heating power supply, this paper proposes a kind of control circuit taking high-speed integrated phase-locked loop CD4046 as the core. The control circuit can carry out real-time frequency tracking to the inverter. In order to to ensure that the inverter works in the weak inductance state, it makes reasonable phase compensation according to the feedback signal. With gaining higher input power factor, it realizes the function of ZVS. The experimental results show that the control circuit has simple structure, stable working performance and higher industrial application value.
Field-based transformation optics
DEFF Research Database (Denmark)
Novitsky, Andrey
2011-01-01
Instead of common definition of the transformation-optics devices via the coordinate transformation we offer the approach founded on boundary conditions for the fields. We demonstrate the effectiveness of the approach by two examples: two-shell cloak and concentrator of electric field. We believe...... that the field-based approach is quite important for effective field control....
Foundation: Transforming data bases into knowledge bases
Purves, R. B.; Carnes, James R.; Cutts, Dannie E.
1987-01-01
One approach to transforming information stored in relational data bases into knowledge based representations and back again is described. This system, called Foundation, allows knowledge bases to take advantage of vast amounts of pre-existing data. A benefit of this approach is inspection, and even population, of data bases through an intelligent knowledge-based front-end.
Lazy Transformation-Based Learning
Samuel, K B
1998-01-01
We introduce a significant improvement for a relatively new machine learning method called Transformation-Based Learning. By applying a Monte Carlo strategy to randomly sample from the space of rules, rather than exhaustively analyzing all possible rules, we drastically reduce the memory and time costs of the algorithm, without compromising accuracy on unseen data. This enables Transformation- Based Learning to apply to a wider range of domains, as it can effectively consider a larger number of different features and feature interactions in the data. In addition, the Monte Carlo improvement decreases the labor demands on the human developer, who no longer needs to develop a minimal set of rule templates to maintain tractability.
Consistency among integral measurements of aggregate decay heat power
Energy Technology Data Exchange (ETDEWEB)
Takeuchi, H.; Sagisaka, M.; Oyamatsu, K.; Kukita, Y. [Nagoya Univ. (Japan)
1998-03-01
Persisting discrepancies between summation calculations and integral measurements force us to assume large uncertainties in the recommended decay heat power. In this paper, we develop a hybrid method to calculate the decay heat power of a fissioning system from those of different fissioning systems. Then, this method is applied to examine consistency among measured decay heat powers of {sup 232}Th, {sup 233}U, {sup 235}U, {sup 238}U and {sup 239}Pu at YAYOI. The consistency among the measured values are found to be satisfied for the {beta} component and fairly well for the {gamma} component, except for cooling times longer than 4000 s. (author)
Model Validation in Ontology Based Transformations
Directory of Open Access Journals (Sweden)
Jesús M. Almendros-Jiménez
2012-10-01
Full Text Available Model Driven Engineering (MDE is an emerging approach of software engineering. MDE emphasizes the construction of models from which the implementation should be derived by applying model transformations. The Ontology Definition Meta-model (ODM has been proposed as a profile for UML models of the Web Ontology Language (OWL. In this context, transformations of UML models can be mapped into ODM/OWL transformations. On the other hand, model validation is a crucial task in model transformation. Meta-modeling permits to give a syntactic structure to source and target models. However, semantic requirements have to be imposed on source and target models. A given transformation will be sound when source and target models fulfill the syntactic and semantic requirements. In this paper, we present an approach for model validation in ODM based transformations. Adopting a logic programming based transformational approach we will show how it is possible to transform and validate models. Properties to be validated range from structural and semantic requirements of models (pre and post conditions to properties of the transformation (invariants. The approach has been applied to a well-known example of model transformation: the Entity-Relationship (ER to Relational Model (RM transformation.
The IHS Transformations Based Image Fusion
Al-Wassai, Firouz Abdullah; Al-Zuky, Ali A
2011-01-01
The IHS sharpening technique is one of the most commonly used techniques for sharpening. Different transformations have been developed to transfer a color image from the RGB space to the IHS space. Through literature, it appears that, various scientists proposed alternative IHS transformations and many papers have reported good results whereas others show bad ones as will as not those obtained which the formula of IHS transformation were used. In addition to that, many papers show different formulas of transformation matrix such as IHS transformation. This leads to confusion what is the exact formula of the IHS transformation?. Therefore, the main purpose of this work is to explore different IHS transformation techniques and experiment it as IHS based image fusion. The image fusion performance was evaluated, in this study, using various methods to estimate the quality and degree of information improvement of a fused image quantitatively.
Ontology Based Model Transformation Infrastructure
Göknil, A.; Topaloglu, N.Y.
2005-01-01
Using MDA in ontology development has been investigated in several works recently. The mappings and transformations between the UML constructs and the OWL elements to develop ontologies are the main concern of these research projects. We propose another approach in order to achieve the collaboration
WCTFR : WRAPPING CURVELET TRANSFORM BASED FACE RECOGNITION
Directory of Open Access Journals (Sweden)
Arunalatha J S
2015-03-01
Full Text Available The recognition of a person based on biological features are efficient compared with traditional knowledge based recognition system. In this paper we propose Wrapping Curvelet Transform based Face Recognition (WCTFR. The Wrapping Curvelet Transform (WCT is applied on face images of database and test images to derive coefficients. The obtained coefficient matrix is rearranged to form WCT features of each image. The test image WCT features are compared with database images using Euclidean Distance (ED to compute Equal Error Rate (EER and True Success Rate (TSR. The proposed algorithm with WCT performs better than Curvelet Transform algorithms used in [1], [10] and [11].
Effective ways to modernize outdated coal heat power plants
Suchkov, S. I.; Kotler, V. R.; Batorshin, V. A.
2016-12-01
An analysis of the state of equipment of 72 outdated coal HPP (heat power plants) of a total capacity 14.3 GW with steam parameters before the turbines p before ≤ 9 MPa, t before = 420-540°C was performed. The equipment is characterized by a considerably low efficiency factor, even if it were converted to burning the natural gas, and by increased release of harmful substances. However, on the most part of the considered HPP, the steam turbines, unlike the boilers, have thus far retained the operation applicability and satisfactory reliability of performance. The analysis has shown that it makes sense to effectively modernize the outdated coal HPP by transformation of their equipment into combined-cycle plant (CCP) with coal gasification, which has high economic and ecological indicators due to thermodynamic advantage of the combined cycle and simpler purification of the generator gas in the process under pressure. As the most rational way of this transformation, the one was recognized wherein—instead of the existing boiler (boilers) or parallel to it—a gasification and gas turbine system is installed with a boiler-utilizer (BU), from which steam is fed to the HPP main steam pipe. In doing this, the basic part of the power station equipment persists. In the world, this kind of reconstruction of steam power equipment is applied widely and successfully, but it is by use of natural gas for the most part. It is reasonable to use the technology developed at Heat Engineering Research Institute (HERI) of hearth-steam gasification of coal and high-temperature purification of the generator gas. The basic scheme and measures on implementation of this method for modernization of outdated coal HPP is creation of CCP with blast-furnace of coal on the basis of accessible and preserved HPP equipment. CCP power is 120 MW, input-output ratio (roughly) 44%, emissions of hazardous substances are 5 mg/MJ dust, 20-60 mg/MJ SO2, and 50-100 mg/MJ NO x . A considerable decrease of
Wavelet transform based watermark for digital images.
Xia, X G; Boncelet, C; Arce, G
1998-12-07
In this paper, we introduce a new multiresolution watermarking method for digital images. The method is based on the discrete wavelet transform (DWT). Pseudo-random codes are added to the large coefficients at the high and middle frequency bands of the DWT of an image. It is shown that this method is more robust to proposed methods to some common image distortions, such as the wavelet transform based image compression, image rescaling/stretching and image halftoning. Moreover, the method is hierarchical.
Digital Autofocusing Method Based on Contourlet Transform
Institute of Scientific and Technical Information of China (English)
无
2007-01-01
The autofocusing technique based on contourlet transform is discussed in this paper and an autofocusing method is proposed for images with much information in certain directions. The experimental results show that theproposed method can focus accurately and the sensitivity ratio is higher than that of the other autofocusing methods based on conventional image processing
Watermark Resistance Analysis Based On Linear Transformation
Directory of Open Access Journals (Sweden)
N.Karthika Devi
2012-06-01
Full Text Available Generally, digital watermark can be embedded in any copyright image whose size is not larger than it. The watermarking schemes can be classified into two categories: spatial domain approach or transform domain approach. Previous works have shown that the transform domain scheme is typically more robust to noise, common image processing, and compression when compared with the spatial transform scheme. Improvements in performance of watermarking schemes can be obtained by exploiting the characteristics of the human visual system (HVS in the watermarking process. We propose a linear transformation based watermarking algorithm. The watermarking bits are embedded into cover image to produce watermarked image. The efficiency of watermark is checked using pre-defined attacks. Attack resistance analysis is done using BER (Bit Error Rate calculation. Finally, the Quality of the watermarked image can be obtained.
Image Enhancement Based on Brushlet Transform
Institute of Scientific and Technical Information of China (English)
HUXinwei; YANGXin
2005-01-01
In this paper, the method of image enhancement based on Brushlet transform is discussed. One favorable characteristic of brushlet is the good localization in both time and frequency domain so it allows treatment for a particular range of data. Furthermore, brushlet can be implemented with faster speed than wavelet transform while preserving the same quality thanks for folding technique and Fast Fourier transform (FFT). The innovation ofthis paper is that after first transforming the image from raw data into brushlet coefficients, we will apply a new nonlinear algorithm to the discrete coefficients. The algorithm is described by a curve which takes the main function of image enhancement. Compared to classical methods, the method presented in this paper not only improves the calculation speed but also provides a high-quality image.
Multilayer modal actuator-based piezoelectric transformers.
Huang, Yao-Tien; Wu, Wen-Jong; Wang, Yen-Chieh; Lee, Chih-Kung
2007-02-01
An innovative, multilayer piezoelectric transformer equipped with a full modal filtering input electrode is reported herein. This modal-shaped electrode, based on the orthogonal property of structural vibration modes, is characterized by full modal filtering to ensure that only the desired vibration mode is excited during operation. The newly developed piezoelectric transformer is comprised of three layers: a multilayered input layer, an insulation layer, and a single output layer. The electrode shape of the input layer is derived from its structural vibration modal shape, which takes advantage of the orthogonal property of the vibration modes to achieve a full modal filtering effect. The insulation layer possesses two functions: first, to couple the mechanical vibration energy between the input and output, and second, to provide electrical insulation between the two layers. To meet the two functions, a low temperature, co-fired ceramic (LTCC) was used to provide the high mechanical rigidity and high electrical insulation. It can be shown that this newly developed piezoelectric transformer has the advantage of possessing a more efficient energy transfer and a wider optimal working frequency range when compared to traditional piezoelectric transformers. A multilayer piezoelectric, transformer-based inverter applicable for use in LCD monitors or portable displays is presented as well.
Transformation media based super focusing antenna
Energy Technology Data Exchange (ETDEWEB)
Lu Wanli; Lin Zhifang [Surface Physics Laboratory, Department of Physics, Fudan University, Shanghai 200433 (China); Chen Huanyang [Department of Physics, Soochow University, Suzhou, Jiangsu 215006 (China); Chan, C T, E-mail: phlin@fudan.edu.c [Department of Physics and the William Mong Institute of NanoScience and Technology, The Hong Kong University of Science and Technology, Clear Water Bay (Hong Kong)
2009-11-07
We propose a new kind of focusing antenna with a large effective diameter based on transformation optics. The device contains a traditional parabolic antenna embedded in a dielectric core and coated by a negative index shell. Numerical simulations are performed to illustrate its advantages. (fast track communication)
Color image encryption based on gyrator transform and Arnold transform
Sui, Liansheng; Gao, Bo
2013-06-01
A color image encryption scheme using gyrator transform and Arnold transform is proposed, which has two security levels. In the first level, the color image is separated into three components: red, green and blue, which are normalized and scrambled using the Arnold transform. The green component is combined with the first random phase mask and transformed to an interim using the gyrator transform. The first random phase mask is generated with the sum of the blue component and a logistic map. Similarly, the red component is combined with the second random phase mask and transformed to three-channel-related data. The second random phase mask is generated with the sum of the phase of the interim and an asymmetrical tent map. In the second level, the three-channel-related data are scrambled again and combined with the third random phase mask generated with the sum of the previous chaotic maps, and then encrypted into a gray scale ciphertext. The encryption result has stationary white noise distribution and camouflage property to some extent. In the process of encryption and decryption, the rotation angle of gyrator transform, the iterative numbers of Arnold transform, the parameters of the chaotic map and generated accompanied phase function serve as encryption keys, and hence enhance the security of the system. Simulation results and security analysis are presented to confirm the security, validity and feasibility of the proposed scheme.
Cryptographic primitives based on cellular transformations
Directory of Open Access Journals (Sweden)
B.V. Izotov
2003-11-01
Full Text Available Design of cryptographic primitives based on the concept of cellular automata (CA is likely to be a promising trend in cryptography. In this paper, the improved method performing data transformations by using invertible cyclic CAs (CCA is considered. Besides, the cellular operations (CO as a novel CAs application in the block ciphers are introduced. Proposed CCAs and COs, integrated under the name of cellular transformations (CT, suit well to be used in cryptographic algorithms oriented to fast software and cheap hardware implementation.
Image edge detection based on beamlet transform
Institute of Scientific and Technical Information of China (English)
Li Jing; Huang Peikang; Wang Xiaohu; Pan Xudong
2009-01-01
Combining beamlet transform with steerable filters, a new edge detection method based on line gra-dient is proposed. Compared with operators based on point local properties, the edge-detection results with this method achieve higher SNR and position accuracy, and are quite helpful for image registration, object identification, etc. Some edge-detection experiments on optical and SAR images that demonstrate the significant improvement over classical edge operators are also presented. Moreover, the template matching result based on edge information of optical reference image and SAR image also proves the validity of this method.
Parallel Graph Transformation based on Merged Approach
Directory of Open Access Journals (Sweden)
Asmaa Aouat
2013-01-01
Full Text Available Graph transformation is one of the key concepts in graph grammar. In order to accelerate the graph transformation, the concept of parallel graph transformation has been proposed by different tools such as AGG tool. The theory of parallel graph transformation used by AGG just allows clarifying the concepts of conflict and dependency between the transformation rules. This work proposes an approach of parallel graph transformations which enables dependent transformation rules to be executed in parallel.
An intersection algorithm based on transformation
Institute of Scientific and Technical Information of China (English)
CHEN Xiao-xia; YONG Jun-hai; CHEN Yu-jian
2006-01-01
How to obtain intersection of curves and surfaces is a fundamental problem in many areas such as computer graphics,CAD/CAM,computer animation,and robotics.Especially,how to deal with singular cases,such as tangency or superposition,is a key problem in obtaining intersection results.A method for solving the intersection problem based on the coordinate transformation is presented.With the Lagrange multiplier method,the minimum distance between the center of a circle and a quadric surface is given as well.Experience shows that the coordinate transformation could significantly simplify the method for calculating intersection to the tangency condition.It can improve the stability of the intersection of given curves and surfaces in singularity cases.The new algorithm is applied in a three dimensional CAD software (GEMS),produced by Tsinghua University.
On an Analog Controlled Precision Heat Power Source
Seilmayer, M.; Katepally, V. K.
2017-07-01
The analog controlled precision heat power source is the main part of a sensor development to estimate real time properties of the primary coolant in a 300 kW process cooling system. The measurement of physical properties like thermal conductivity or thermal diffusion requires a precise and accurate heater. The constant heat flux is then applied to the liquid under test to acquire its different properties. Here, commonly established control methods of heating with constant current or constant voltage may fail because the heating resistor changes its resistance with temperature. The idea is to utilize a power monitor circuit like the LT2940, which contains an analog multiplier with a control loop around it. The initial design and its assumed uncertainties will be discussed. The first version of the power controller shows an outstanding performance in terms of precision in a steady state. Compared to conventional switching mode power sources the approach with an analog controlled heater avoids EMI issues as well. The main goal of the present design is a precise source of heat power with less than 0.5% of error.
Complex Wavelet Transform-Based Face Recognition
Directory of Open Access Journals (Sweden)
2009-03-01
Full Text Available Complex approximately analytic wavelets provide a local multiscale description of images with good directional selectivity and invariance to shifts and in-plane rotations. Similar to Gabor wavelets, they are insensitive to illumination variations and facial expression changes. The complex wavelet transform is, however, less redundant and computationally efficient. In this paper, we first construct complex approximately analytic wavelets in the single-tree context, which possess Gabor-like characteristics. We, then, investigate the recently developed dual-tree complex wavelet transform (DT-CWT and the single-tree complex wavelet transform (ST-CWT for the face recognition problem. Extensive experiments are carried out on standard databases. The resulting complex wavelet-based feature vectors are as discriminating as the Gabor wavelet-derived features and at the same time are of lower dimension when compared with that of Gabor wavelets. In all experiments, on two well-known databases, namely, FERET and ORL databases, complex wavelets equaled or surpassed the performance of Gabor wavelets in recognition rate when equal number of orientations and scales is used. These findings indicate that complex wavelets can provide a successful alternative to Gabor wavelets for face recognition.
Pedestrian detection based on redundant wavelet transform
Huang, Lin; Ji, Liping; Hu, Ping; Yang, Tiejun
2016-10-01
Intelligent video surveillance is to analysis video or image sequences captured by a fixed or mobile surveillance camera, including moving object detection, segmentation and recognition. By using it, we can be notified immediately in an abnormal situation. Pedestrian detection plays an important role in an intelligent video surveillance system, and it is also a key technology in the field of intelligent vehicle. So pedestrian detection has very vital significance in traffic management optimization, security early warn and abnormal behavior detection. Generally, pedestrian detection can be summarized as: first to estimate moving areas; then to extract features of region of interest; finally to classify using a classifier. Redundant wavelet transform (RWT) overcomes the deficiency of shift variant of discrete wavelet transform, and it has better performance in motion estimation when compared to discrete wavelet transform. Addressing the problem of the detection of multi-pedestrian with different speed, we present an algorithm of pedestrian detection based on motion estimation using RWT, combining histogram of oriented gradients (HOG) and support vector machine (SVM). Firstly, three intensities of movement (IoM) are estimated using RWT and the corresponding areas are segmented. According to the different IoM, a region proposal (RP) is generated. Then, the features of a RP is extracted using HOG. Finally, the features are fed into a SVM trained by pedestrian databases and the final detection results are gained. Experiments show that the proposed algorithm can detect pedestrians accurately and efficiently.
Transform Domain Fingerprint Identification Based on DTCWT
Directory of Open Access Journals (Sweden)
Jossy P. George
2012-01-01
Full Text Available The physiological biometric characteristics are better compared to behavioral biometric identification of human beings to identify a person. In this paper, we propose Transform Domain Fingerprint Identification Based on DTCWT. The original Fingerprint is cropped and resized to suitable dimension to apply DTCWT. The DTCWT is applied on Fingerprint to generate coefficient which form features. The performance analysis is discussed with different levels of DTCWT and also with different sizes of Fingerprint database. It is observed that the recognition rate is better in the case of level 7 compared to other levels of DTCWT.
Mitarai, O.; Sagara, A.; Chikaraishi, H.; Imagawa, S.; Watanabe, K.; Shishkin, A. A.; Motojima, O.
2007-11-01
Minimization of the external heating power to access self-ignition is advantageous to increase the reactor design flexibility and to reduce the capital and operating costs of the plasma heating device in a helical reactor. In this work we have discovered that a larger density limit leads to a smaller value of the required confinement enhancement factor, a lower density limit margin reduces the external heating power and over 300 s of the fusion power rise-up time makes it possible to reach a minimized heating power. While the fusion power rise-up time in a tokamak is limited by the OH transformer flux or the current drive capability, any fusion power rise-up time can be employed in a helical reactor for reducing the thermal stresses of the blanket and shields, because the confinement field is generated by the external helical coils.
Heat powered refrigeration compressor. Semi-annual technical report
Energy Technology Data Exchange (ETDEWEB)
Goad, R.R.
1981-01-01
The objective of this program is to develop and improve the design of previously started prototypes of the Heat Powered Refrigeration Compressor. To build this prototype and ready it for testing by the University of Evansville is another goal. This prototype will be of similar capacity as the compressor that will eventually be commercially produced. This unit can operate on almost any moderate temperature water heat source. This heat source could include such applications as industrial waste heat, solar, wood burning stove, resistance electrical heat produced by a windmill, or even perhaps heat put out by the condenser of another refrigeration system. Work performed in the past four months has consisted of: engineering of HX-1; comparisons of specifications from different companies to ensure state of the art applications of parts for project; coordinating project requirements with machine shop; designing condenser; and partial assembly of HX-1.
Motion Analysis Based on Invertible Rapid Transform
Directory of Open Access Journals (Sweden)
J. Turan
1999-06-01
Full Text Available This paper presents the results of a study on the use of invertible rapid transform (IRT for the motion estimation in a sequence of images. Motion estimation algorithms based on the analysis of the matrix of states (produced in the IRT calculation are described. The new method was used experimentally to estimate crowd and traffic motion from the image data sequences captured at railway stations and at high ways in large cities. The motion vectors may be used to devise a polar plot (showing velocity magnitude and direction for moving objects where the dominant motion tendency can be seen. The experimental results of comparison of the new motion estimation methods with other well known block matching methods (full search, 2D-log, method based on conventional (cross correlation (CC function or phase correlation (PC function for application of crowd motion estimation are also presented.
Clinical data interoperability based on archetype transformation.
Costa, Catalina Martínez; Menárguez-Tortosa, Marcos; Fernández-Breis, Jesualdo Tomás
2011-10-01
The semantic interoperability between health information systems is a major challenge to improve the quality of clinical practice and patient safety. In recent years many projects have faced this problem and provided solutions based on specific standards and technologies in order to satisfy the needs of a particular scenario. Most of such solutions cannot be easily adapted to new scenarios, thus more global solutions are needed. In this work, we have focused on the semantic interoperability of electronic healthcare records standards based on the dual model architecture and we have developed a solution that has been applied to ISO 13606 and openEHR. The technological infrastructure combines reference models, archetypes and ontologies, with the support of Model-driven Engineering techniques. For this purpose, the interoperability infrastructure developed in previous work by our group has been reused and extended to cover the requirements of data transformation.
Safe corrosion inhibitor for treating cooling water on heat power engineering plants
Nikolaeva, L. A.; Khasanova, D. I.; Mukhutdinova, E. R.; Safin, D. Kh.; Sharifullin, I. G.
2017-08-01
Heat power engineering (HPE) consumes significant volumes of water. There are, therefore, problems associated with corrosion, biological fouling, salt deposits, and sludge formation on functional surfaces of heat power equipment. One of the effective ways to solve these problems is the use of inhibitory protection. The development of new Russian import-substituting environmentally friendly inhibitors is very relevant. This work describes experimental results on the OPC-800 inhibitor (TU 2415-092-00206 457-2013), which was produced at Karpov Chemical Plant and designed to remove mineral deposits, scale, and biological fouling from the surfaces of water-rotation node systems on HPE objects. This reagent is successfully used as an effective corrosion inhibitor in the water recycling systems of Tatarstan petrochemical enterprises. To save fresh make-up water, the circulating system is operated in a no-blow mode, which is characterized by high evaporation and salt content coefficients. It was experimentally found that corrosion rate upon treatment of recycled water with the OPC-800 inhibitor is 0.08-0.10 mm/year. HPE mainly uses inhibitors based on oxyethylidene diphosphonic (OEDPA) and nitrilotrimethylphosphonic (NTMPA) acids. The comparative characteristic of inhibition efficiency for OPC-800 and OEDF-Zn-U2 is given. The results obtained indicate that OPC-800 can be used as an inhibitor for treatment of cooling water in HPE plants. In this case, it is necessary to take into account the features of water rotation of a thermal power plant.
Generalized Tree-Based Wavelet Transform
Ram, Idan; Cohen, Israel
2010-01-01
In this paper we propose a new wavelet transform applicable to functions defined on graphs, high dimensional data and networks. The proposed method generalizes the Haar-like transform proposed in \\cite{gavish2010mwot}, and it is similarly defined via a hierarchical tree, which is assumed to capture the geometry and structure of the input data. It is applied to the data using a multiscale filtering and decimation scheme, which can employ different wavelet filters. We propose a tree construction method which results in efficient representation of the input function in the transform domain. We show that the proposed transform is more efficient than both the 1D and 2D separable wavelet transforms in representing images. We also explore the application of the proposed transform to image denoising, and show that combined with a subimage averaging scheme, it achieves denoising results which are similar to the ones obtained with the K-SVD algorithm.
Singularity Detection of Signals Based on their Wavelet Transform
Institute of Scientific and Technical Information of China (English)
无
2000-01-01
This paper introduces a multiresolution decomposition of signals based on their wavelet transform. The different behaviors of the wavelet transform between the signal and the noise are compared. An algorithm of singularity detection and processing in signals is proposed by the modulus maximum of the wavelet transform.
NOVEL ADAPTIVE MULTIUSER DETECTIONALGORITHM BASED ON WAVELET TRANSFORM
Institute of Scientific and Technical Information of China (English)
ZHANGXiao-fei; XUDa-zhuan; YANGBei
2004-01-01
The wavelet transform-based adaptive multiuser detection algorithm is presented. The novel adaptive multiuser detection algorithm uses the wavelet transform for the preprocessing, and wavelet-transformed signal uses LMS algorithm to implement the adaptive multiuser detection. The algorithm makes use of wavelet transform to divide the wavelet space, which shows that the wavelet transform has a better decorrelation ability and leads to better convergence. White noise can be wiped off under the wavelet transform according to different characteristics of signal and white noise under the wavelet transform. Theoretical analyses and simulations demonstrate that the algorithm converges faster than the conventional adaptive multiuser detection algorithm, and has the better performance. Simulation results reveal that the algorithm convergence relates to the wavelet base, and show that the algorithm convergence gets better with the increasing of regularity for the same series of the wavelet base. Finally the algorithm shows that it can be easily implemented.
GEOMETRICALLY INVARIANT WATERMARKING BASED ON RADON TRANSFORMATION
Institute of Scientific and Technical Information of China (English)
Cai Lian; Du Sidan; Gao Duntang
2005-01-01
The weakness of classical watermarking methods is the vulnerability to geometrical distortions that widely occur during normal use of the media. In this letter, a new imagewatermarking method is presented to resist Rotation, Scale and Translation (RST) attacks. The watermark is embedded into a domain obtained by taking Radon transform of a circular area selected from the original image, and then extracting Two-Dimensional (2-D) Fourier magnitude of the Radon transformed image. Furthermore, to prevent the watermarked image from degrading due to inverse Radon transform, watermark signal is inversely Radon transformed individually.Experimental results demonstrate that the proposed scheme is able to withstand a variety of attacks including common geometric attacks.
Estimation and harvesting of human heat power for wearable electronic devices
Dziurdzia, P.; Brzozowski, I.; Bratek, P.; Gelmuda, W.; Kos, A.
2016-01-01
The paper deals with the issue of self-powered wearable electronic devices that are capable of harvesting free available energy dissipated by the user in the form of human heat. The free energy source is intended to be used as a secondary power source supporting primary battery in a sensor bracelet. The main scope of the article is a presentation of the concept for a measuring setup used to quantitative estimation of heat power sources in different locations over the human body area. The crucial role in the measurements of the human heat plays a thermoelectric module working in the open circuit mode. The results obtained during practical tests are confronted with the requirements of the dedicated thermoelectric generator. A prototype design of a human warmth energy harvester with an ultra-low power DC-DC converter based on the LTC3108 circuit is analysed.
Shape classification based on singular value decomposition transform
Institute of Scientific and Technical Information of China (English)
SHAABAN Zyad; ARIF Thawar; BABA Sami; KREKOR Lala
2009-01-01
In this paper, a new shape classification system based on singular value decomposition (SVD) transform using nearest neighbour classifier was proposed. The gray scale image of the shape object was converted into a black and white image. The squared Euclidean distance transform on binary image was applied to extract the boundary image of the shape. SVD transform features were extracted from the the boundary of the object shapes. In this paper, the proposed classification system based on SVD transform feature extraction method was compared with classifier based on moment invariants using nearest neighbour classifier. The experimental results showed the advantage of our proposed classification system.
Directory of Open Access Journals (Sweden)
K. Vijayarekha
2012-12-01
Full Text Available The aim of this study is to classify the citrus fruit images based on the external defect using the features extracted in the spectral domain (transform based and to compare the performance of each of the feature set. Automatic classification of agricultural produce by machine vision technology plays a very important role as it improves the quality of grading. Multi resolution analysis using wavelets yields better results for pattern recognition and object classification. This study details about an image processing method applied for classifying three external surface defects of citrus fruit using wavelet transforms based features and an artificial neural network. The Discrete Wavelet Transform (DWT, Stationary Wavelet Transform (SWT and Wavelet Packet Transform (WPT features viz. mean and standard deviation of the details and approximations were extracted from citrus fruit images and used for classifying the defects. The DWT and SWT features were extracted from 40x40 sub-windows of the fruit image. The WPT features were extracted from the full fruit image of size 640x480. The classification results pertaining to the three wavelet transforms are reported and discussed.
An Investigation of Transformation-Based Learning in Discourse
Samuel, K B; Vijay-Shanker, K; Samuel, Ken; Carberry, Sandra
1998-01-01
This paper presents results from the first attempt to apply Transformation-Based Learning to a discourse-level Natural Language Processing task. To address two limitations of the standard algorithm, we developed a Monte Carlo version of Transformation-Based Learning to make the method tractable for a wider range of problems without degradation in accuracy, and we devised a committee method for assigning confidence measures to tags produced by Transformation-Based Learning. The paper describes these advances, presents experimental evidence that Transformation-Based Learning is as effective as alternative approaches (such as Decision Trees and N-Grams) for a discourse task called Dialogue Act Tagging, and argues that Transformation-Based Learning has desirable features that make it particularly appealing for the Dialogue Act Tagging task.
A Novel Calibrator for Electronic Transformers Based on IEC 61850
Directory of Open Access Journals (Sweden)
Baoxiang PAN
2013-01-01
Full Text Available It is necessary for electronic transformer to make calibration before putting it into practice. To solve the problems in actual calibration process, a novel electronic transformer calibrator is designed. In principle, this system adopts both the direct method and the difference method, which are two popular methods for electronic transformer calibration, by this way the application of the system is extended with its reliability improved. In the system design, based on virtual instrument technology, LabVIEW and WinPCap toolkit are used to develop the application software, and it is able to calibrate those electronic transformers following the standard of IEC 61850. In the calculation of ratio and phase error based on fast Fourier transform, a new window function is introduced, and thus the accuracy of calibration, influenced by the frequency vibration, is improved. This research provides theoretic support and practical reference to the development of intelligent calibrator for electronic transformers.
A Fractional Random Wavelet Transform Based Image Steganography
G.K. Rajini; RAMACHANDRA REDDY G.
2015-01-01
This study presents a novel technique for image steganography based on Fractional Random Wavelet Transform. This transform has all the features of wavelet transform with randomness and fractional order built into it. The randomness and fractional order in the algorithm brings in robustness and additional layers of security to steganography. The stegano image generated by this algorithm contains both cover image and hidden image and image degradation is not observed in it. The steganography st...
Automatic Image Registration Algorithm Based on Wavelet Transform
Institute of Scientific and Technical Information of China (English)
LIU Qiong; NI Guo-qiang
2006-01-01
An automatic image registration approach based on wavelet transform is proposed. This proposed method utilizes multiscale wavelet transform to extract feature points. A coarse-to-fine feature matching method is utilized in the feature matching phase. A two-way matching method based on cross-correlation to get candidate point pairs and a fine matching based on support strength combine to form the matching algorithm. At last, based on an affine transformation model, the parameters are iteratively refined by using the least-squares estimation approach. Experimental results have verified that the proposed algorithm can realize automatic registration of various kinds of images rapidly and effectively.
Watermarking on 3D mesh based on spherical wavelet transform
Institute of Scientific and Technical Information of China (English)
金剑秋; 戴敏雅; 鲍虎军; 彭群生
2004-01-01
In this paper we propose a robust watermarking algorithm for 3D mesh. The algorithm is based on spherical wavelet transform. Our basic idea is to decompose the original mesh into a series of details at different scales by using spherical wavelet transform; the watermark is then embedded into the different levels of details. The embedding process includes: global sphere parameterization, spherical uniform sampling, spherical wavelet forward transform, embedding watermark, spherical wavelet inverse transform, and at last resampling the mesh watermarked to recover the topological connectivity of the original model. Experiments showed that our algorithm can improve the capacity of the watermark and the robustness of watermarking against attacks.
Clone Detection for Graph-Based Model Transformation Languages
DEFF Research Database (Denmark)
Strüber, Daniel; Plöger, Jennifer; Acretoaie, Vlad
2016-01-01
has been proposed for programming and modeling languages; yet no specific ones have emerged for model transformation languages. In this paper, we explore clone detection for graph-based model transformation languages. We introduce potential use cases for such techniques in the context of constructive...
Asymmetrical transformer-based embedded Z-source inverters
DEFF Research Database (Denmark)
Wei, Mo; Loh, Poh Chiang; Blaabjerg, Frede
2013-01-01
their performances, a number of asymmetrical transformer-based embedded Z-source inverters are proposed. Through theoretical derivation and experiments, the proposed inverters have been shown to draw a smooth input current and produce a high gain by varying the transformer turns ratio n. The range of variation for n...
Combined Heat & Power Using the Infinia Concentrated Solar CHP PowerDish System
2013-08-01
FINAL REPORT Combined Heat & Power Using the Infinia Concentrated Solar CHP PowerDish System ESTCP Project EW-201145 AUGUST 2013...Combined Heat & Power Using the Infinia Concentrated Solar CHP PowerDish System 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6...demonstrated the capabilities of the Infinia PowerDish? CHP technology to generate clean solar thermal and electric energy compatible with domestic and
Finite Countermodel Based Verification for Program Transformation (A Case Study
Directory of Open Access Journals (Sweden)
Alexei P. Lisitsa
2015-12-01
Full Text Available Both automatic program verification and program transformation are based on program analysis. In the past decade a number of approaches using various automatic general-purpose program transformation techniques (partial deduction, specialization, supercompilation for verification of unreachability properties of computing systems were introduced and demonstrated. On the other hand, the semantics based unfold-fold program transformation methods pose themselves diverse kinds of reachability tasks and try to solve them, aiming at improving the semantics tree of the program being transformed. That means some general-purpose verification methods may be used for strengthening program transformation techniques. This paper considers the question how finite countermodels for safety verification method might be used in Turchin's supercompilation method. We extract a number of supercompilation sub-algorithms trying to solve reachability problems and demonstrate use of an external countermodel finder for solving some of the problems.
An improved Hough transform-based fingerprint alignment approach
CSIR Research Space (South Africa)
Mlambo, CS
2014-11-01
Full Text Available An improved Hough Transform based fingerprint alignment approach is presented, which improves computing time and memory usage with accurate alignment parameter (rotation and translation) results. This is achieved by studying the strengths...
Multispectral image pansharpening based on the contourlet transform
Energy Technology Data Exchange (ETDEWEB)
Amro, Israa; Mateos, Javier, E-mail: iamro@correo.ugr.e, E-mail: jmd@decsai.ugr.e [Departamento de Ciencias de la Computacion e I.A., Universidad de Granada, 18071 Granada (Spain)
2010-02-01
Pansharpening is a technique that fuses the information of a low resolution multispectral image (MS) and a high resolution panchromatic image (PAN), usually remote sensing images, to provide a high resolution multispectral image. In the literature, this task has been addressed from different points of view being one of the most popular the wavelets based algorithms. Recently, the contourlet transform has been proposed. This transform combines the advantages of the wavelets transform with a more efficient directional information representation. In this paper we propose a new pansharpening method based on contourlets, compare with its wavelet counterpart and assess its performance numerically and visually.
Transformation to problem and project based learning
DEFF Research Database (Denmark)
2006-01-01
. However, the internal factors at the institutional level may be unknown. Institutions have developed many different pedagogical models, using very different strategies for development. Nearly all Danish engineering institutions have implemented elements of Problem Based and Project Based Learning (PBL...
Digital watermarking : An approach based on Hilbert transform
Agarwal, Rashmi; Santhanam, M S; Srinivas, K; Venugopalan, K
2010-01-01
Most of the well known algorithms for watermarking of digital images involve transformation of the image data to Fourier or singular vector space. In this paper, we introduce watermarking in Hilbert transform domain for digital media. Generally, if the image is a matrix of order $m$ by $n$, then the transformed space is also an image of the same order. However, with Hilbert transforms, the transformed space is of order $2m$ by $2n$. This allows for more latitude in storing the watermark in the host image. Based on this idea, we propose an algorithm for embedding and extracting watermark in a host image and analytically obtain a parameter related to this procedure. Using extensive simulations, we show that the algorithm performs well even if the host image is corrupted by various attacks.
Rule-based transformations for geometric modelling
Directory of Open Access Journals (Sweden)
Thomas Bellet
2011-02-01
Full Text Available The context of this paper is the use of formal methods for topology-based geometric modelling. Topology-based geometric modelling deals with objects of various dimensions and shapes. Usually, objects are defined by a graph-based topological data structure and by an embedding that associates each topological element (vertex, edge, face, etc. with relevant data as their geometric shape (position, curve, surface, etc. or application dedicated data (e.g. molecule concentration level in a biological context. We propose to define topology-based geometric objects as labelled graphs. The arc labelling defines the topological structure of the object whose topological consistency is then ensured by labelling constraints. Nodes have as many labels as there are different data kinds in the embedding. Labelling constraints ensure then that the embedding is consistent with the topological structure. Thus, topology-based geometric objects constitute a particular subclass of a category of labelled graphs in which nodes have multiple labels.
Rule-based transformations for geometric modelling
Bellet, Thomas; Gall, Pascale Le; 10.4204/EPTCS.48.5
2011-01-01
The context of this paper is the use of formal methods for topology-based geometric modelling. Topology-based geometric modelling deals with objects of various dimensions and shapes. Usually, objects are defined by a graph-based topological data structure and by an embedding that associates each topological element (vertex, edge, face, etc.) with relevant data as their geometric shape (position, curve, surface, etc.) or application dedicated data (e.g. molecule concentration level in a biological context). We propose to define topology-based geometric objects as labelled graphs. The arc labelling defines the topological structure of the object whose topological consistency is then ensured by labelling constraints. Nodes have as many labels as there are different data kinds in the embedding. Labelling constraints ensure then that the embedding is consistent with the topological structure. Thus, topology-based geometric objects constitute a particular subclass of a category of labelled graphs in which nodes hav...
Novel Adaptive Beamforming Algorithm Based on Wavelet Packet Transform
Institute of Scientific and Technical Information of China (English)
Zhang Xiaofei; Xu Dazhuan
2005-01-01
An analysis of the received signal of array antennas shows that the received signal has multi-resolution characteristics, and hence the wavelet packet theory can be used to detect the signal. By emplying wavelet packet theory to adaptive beamforming, a wavelet packet transform-based adaptive beamforming algorithm (WP-ABF) is proposed . This WP-ABF algorithm uses wavelet packet transform as the preprocessing, and the wavelet packet transformed signal uses least mean square algorithm to implement the adaptive beamforming. White noise can be wiped off under wavelet packet transform according to the different characteristics of signal and white under the wavelet packet transform. Theoretical analysis and simulations demonstrate that the proposed WP-ABF algorithm converges faster than the conventional adaptive beamforming algorithm and the wavelet transform-based beamforming algorithm. Simulation results also reveal that the convergence of the algorithm relates closely to the wavelet base and series; that is, the algorithm convergence gets better with the increasing of series, and for the same series of wavelet base the convergence gets better with the increasing of regularity.
Energy Technology Data Exchange (ETDEWEB)
LACKS,S.A.
2003-10-09
Transformation, which alters the genetic makeup of an individual, is a concept that intrigues the human imagination. In Streptococcus pneumoniae such transformation was first demonstrated. Perhaps our fascination with genetics derived from our ancestors observing their own progeny, with its retention and assortment of parental traits, but such interest must have been accelerated after the dawn of agriculture. It was in pea plants that Gregor Mendel in the late 1800s examined inherited traits and found them to be determined by physical elements, or genes, passed from parents to progeny. In our day, the material basis of these genetic determinants was revealed to be DNA by the lowly bacteria, in particular, the pneumococcus. For this species, transformation by free DNA is a sexual process that enables cells to sport new combinations of genes and traits. Genetic transformation of the type found in S. pneumoniae occurs naturally in many species of bacteria (70), but, initially only a few other transformable species were found, namely, Haemophilus influenzae, Neisseria meningitides, Neisseria gonorrheae, and Bacillus subtilis (96). Natural transformation, which requires a set of genes evolved for the purpose, contrasts with artificial transformation, which is accomplished by shocking cells either electrically, as in electroporation, or by ionic and temperature shifts. Although such artificial treatments can introduce very small amounts of DNA into virtually any type of cell, the amounts introduced by natural transformation are a million-fold greater, and S. pneumoniae can take up as much as 10% of its cellular DNA content (40).
DEFF Research Database (Denmark)
Peters, Terri
2011-01-01
Artiklen diskuterer ordet "transformation" med udgangspunkt i dels hvorledes ordet bruges i arkitektfaglig terminologi og dels med fokus på ordets potentielle indhold og egnethed i samme teminologi.......Artiklen diskuterer ordet "transformation" med udgangspunkt i dels hvorledes ordet bruges i arkitektfaglig terminologi og dels med fokus på ordets potentielle indhold og egnethed i samme teminologi....
DEFF Research Database (Denmark)
Peters, Terri
2011-01-01
Artiklen diskuterer ordet "transformation" med udgangspunkt i dels hvorledes ordet bruges i arkitektfaglig terminologi og dels med fokus på ordets potentielle indhold og egnethed i samme teminologi.......Artiklen diskuterer ordet "transformation" med udgangspunkt i dels hvorledes ordet bruges i arkitektfaglig terminologi og dels med fokus på ordets potentielle indhold og egnethed i samme teminologi....
Improved method for pulse sorting based on PRI transform
Ren, Chunhui; Cao, Junqing; Fu, Yusheng; Barner, Kenneth E.
2014-06-01
To solve the problem of pulse sorting in complex electromagnetic environment, we propose an improved method for pulse sorting through in-depth analysis of the PRI transform algorithm principle and the advantages and disadvantages in this paper. The method is based on the traditional PRI transform algorithm, using spectral analysis of PRI transform spectrum to estimate the PRI centre value of jitter signal. Simulation results indicate that, the improved sorting method overcome the shortcomings of the traditional PRI jitter separation algorithm which cannot effectively sort jitter pulse sequence, in addition to the advantages of simple and accurate.
Broadband unidirectional behavior of electromagnetic waves based on transformation optics
Zang, Xiaofei; Zhu, Yiming; Ji, Xuebin; Chen, Lin; Hu, Qing; Zhuang, Songlin
2017-01-01
High directive antennas are fundamental elements for microwave communication and information processing. Here, inspired by the method of transformation optics, we propose and demonstrate a transformation medium to control the transmission path of a point source, resulting in the unidirectional behavior of electromagnetic waves (directional emitter) without any reflectors. The network of inductor-capacitor transmission lines is designed to experimentally realize the transformation medium. Furthermore, the designed device can work in a broadband frequency range. The unidirectional-manner-based device demonstrated in this work will be an important step forward in developing a new type of directive antennas.
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.
MIXED SCHEME FOR IMAGE EDGE DETECTION BASED ON WAVELET TRANSFORM
Institute of Scientific and Technical Information of China (English)
Xie Hongmei; Yu Bianzhang; Zhao Jian
2004-01-01
A mixed scheme based on Wavelet Transformation (WT) is proposed for image edge detection. The scheme combines the wavelet transform and traditional Sobel and LoG (Laplacian of Gaussian) operator edge-detection algorithms. The precise theory analysis is given to show that the wavelet transformation has an advantage for signal processing. Simulation results show that the new scheme is better than only using the Sobel or LoG methods. Complexity analysis is also given and the conclusion is acceptable, therefore the proposed scheme is effective for edge detection.
Transformer real-time reliability model based on operating conditions
Institute of Scientific and Technical Information of China (English)
HE Jian; CHENG Lin; SUN Yuan-zhang
2007-01-01
Operational reliability evaluation theory reflects real-time reliability level of power system. The component failure rate varies with operating conditions. The impact of real-time operating conditions such as ambient temperature and transformer MVA (megavolt-ampere) loading on transformer insulation life is studied in this paper. The formula of transformer failure rate based on the winding hottest-spot temperature (HST) is given. Thus the real-time reliability model of transformer based on operating conditions is presented. The work is illustrated using the 1979 IEEE Reliability Test System. The changes of operating conditions are simulated by using hourly load curve and temperature curve, so the curves of real-time reliability indices are obtained by using operational reliability evaluation.
Improved Spectral Representation for Birdcall Based on Fractional Fourier Transform
Institute of Scientific and Technical Information of China (English)
无
2008-01-01
A novel spectral representation based on fractional Fourier transform (FrFT) is proposed and applied to birdcall analysis. The FrFT-based spectrogram of a signal is derived and compared with its FT-based counterpart, and the spectrum gathering method is used to show the energy distribution related to the pitch frequency. The fixed transform order and adaptive orders for FrFT are tested. The fixed order can be obtained empirically or calculated according to the known chirp rate. The adaptive optimal orders are determined by using ambiguity function. Experimental results with birdcalls show that the FrFT-based spectrogram with an optimal transform order has higher resolution than its STFT-based counterpart, and the better performance can be achieved if adaptive orders are used.
Energy Technology Data Exchange (ETDEWEB)
Novitsky, Andrey [Department of Theoretical Physics, Belarusian State University, Nezavisimosti Avenue 4, 220050 Minsk (Belarus); Qiu, C-W [Research Laboratory of Electronics, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA 02139 (United States); Zouhdi, Said [Laboratoire de Genie Electrique de Paris, SUPELEC, Plateau de Moulon 91192, Gif-sur-Yvette (France)], E-mail: eleqc@nus.edu.sg
2009-11-15
Based on the concept of the cloak generating function, we propose an implicit transformation-independent method for the required parameters of spherical cloaks without knowing the needed coordinate transformation beforehand. A non-ideal discrete model is used to calculate and optimize the total scattering cross-sections of different profiles of the generating function. A bell-shaped quadratic spherical cloak is found to be the best candidate, which is further optimized by controlling the design parameters involved. Such improved invisibility is steady even when the model is highly discretized.
2012-06-28
... Federal Aviation Administration Draft Specification for Airport Light Bases, Transformer Housings... comment on the Draft ``Specification for Airport Light Bases, Transformer Housings, Junction Boxes, and... recommendations for airport light bases, transformer housings, junction boxes and accessories. The FAA has...
Baker, W.R.
1959-08-25
Transformers of a type adapted for use with extreme high power vacuum tubes where current requirements may be of the order of 2,000 to 200,000 amperes are described. The transformer casing has the form of a re-entrant section being extended through an opening in one end of the cylinder to form a coaxial terminal arrangement. A toroidal multi-turn primary winding is disposed within the casing in coaxial relationship therein. In a second embodiment, means are provided for forming the casing as a multi-turn secondary. The transformer is characterized by minimized resistance heating, minimized external magnetic flux, and an economical construction.
Effect of the Hollow Cathode Heat Power on the Performance of an Hall-Effect Thruster
Institute of Scientific and Technical Information of China (English)
NING Zhongxi; YU Daren; LI Hong; YAN Guojun
2009-01-01
Effect of the hollow cathode heat power on the performance of a Hall-effect thruster is investigated. The variations in the Hall-effect thruster's performance (thrust, specific impulse and anode efficiency) with the hollow cathode heat power was obtained from the analysis of the experimental data. Through an analysis on the coupling relationship between the electrons emitted from the hollow cathode and the environmental plasma, it was found that the heat power would affect the electron emission of the emitter and the space potential of the coupling zone, which would lead to a change in the effective discharge voltage. The experimental data agree well with the results of calculation which can be used to explain the experimental phenomena.
Invariant wavelet transform-based automatic target recognition
Sadovnik, Lev S.; Rashkovskiy, Oleg; Tebelev, Igor
1995-03-01
The authors' previous work (SPIE Vol. 2237) on scale-, rotation- and shift-invariant wavelet transform is extended to accommodate multiple objects in the scene and a nonuniform background. After background elimination and segmentation, a set of windows each containing a single object are analyzed based on an invariant wavelet feature extraction algorithm and neural network-based classifier.
Elliptic grid generation based on Laplace equations and algebraic transformations
Energy Technology Data Exchange (ETDEWEB)
Spekreuse, S.P. [National Aerospace Lab., Amsterdam (Netherlands)
1995-04-01
An elliptic grid generation method is presented to generate boundary conforming grids in domains in 2D and 3D physical space and on minimal surfaces and parametrized surfaces in 3D physical space. The elliptic grid generation method is based on the use of a composite mapping. This composite mapping consists of a nonlinear transfinite algebraic transformation and an elliptic transformation. The elliptic transformation is based on the Laplace equations for domains, or on the Laplace-Beltrami equations for surfaces. The algebraic transformation maps the computational space one to-one onto a parameter space. The elliptic transformation maps the parameter space one-to-one onto the domains or surfaces. The composition of these two mapping is a differentiable one-to-one mapping from computational space onto the domains or surfaces and has a nonvanishing Jacobian. This composite mapping defines the grid point distribution in the interior of the domains or surfaces. For domains and minimal surfaces, the composite mapping obeys a nonlinear elliptic Poisson system with control functions completely defined by the algebraic transformation. The solution of the Poisson systems is obtained by Picard iteration and black-box multigrid solvers. For parametrized curved surfaces, it is not necessary to define and solve a nonlinear elliptic Poisson system. Instead a linear elliptic system and an inversion problem is solved to generate the grid in the interior of the surface.
A Fractional Random Wavelet Transform Based Image Steganography
Directory of Open Access Journals (Sweden)
G.K. Rajini
2015-04-01
Full Text Available This study presents a novel technique for image steganography based on Fractional Random Wavelet Transform. This transform has all the features of wavelet transform with randomness and fractional order built into it. The randomness and fractional order in the algorithm brings in robustness and additional layers of security to steganography. The stegano image generated by this algorithm contains both cover image and hidden image and image degradation is not observed in it. The steganography strives for security and pay load capacity. The performance measures like PeakSignal to Noise Ratio (PSNR, Mean Square Error (MSE, Structural Similarity Index Measure (SSIM and Universal Image Quality Index (UIQI are computed. In this proposed algorithm, imperceptibility and robustness are verified and it can sustain geometric transformations like rotation, scaling and translation and is compared with some of the existing algorithms. The numerical results show the effectiveness of the proposed algorithm.
Design Transformations for Rule-based Procedural Modeling
Lienhard, Stefan
2017-05-24
We introduce design transformations for rule-based procedural models, e.g., for buildings and plants. Given two or more procedural designs, each specified by a grammar, a design transformation combines elements of the existing designs to generate new designs. We introduce two technical components to enable design transformations. First, we extend the concept of discrete rule switching to rule merging, leading to a very large shape space for combining procedural models. Second, we propose an algorithm to jointly derive two or more grammars, called grammar co-derivation. We demonstrate two applications of our work: we show that our framework leads to a larger variety of models than previous work, and we show fine-grained transformation sequences between two procedural models.
Yan, Jingwen; Chen, Jiazhen
2007-03-01
A new hyperspectral image compression method of spectral feature classification vector quantization (SFCVQ) and embedded zero-tree of wavelet (EZW) based on Karhunen-Loeve transformation (KLT) and integer wavelet transformation is represented. In comparison with the other methods, this method not only keeps the characteristics of high compression ratio and easy real-time transmission, but also has the advantage of high computation speed. After lifting based integer wavelet and SFCVQ coding are introduced, a system of nearly lossless compression of hyperspectral images is designed. KLT is used to remove the correlation of spectral redundancy as one-dimensional (1D) linear transform, and SFCVQ coding is applied to enhance compression ratio. The two-dimensional (2D) integer wavelet transformation is adopted for the decorrelation of 2D spatial redundancy. EZW coding method is applied to compress data in wavelet domain. Experimental results show that in comparison with the method of wavelet SFCVQ (WSFCVQ), the method of improved BiBlock zero tree coding (IBBZTC) and the method of feature spectral vector quantization (FSVQ), the peak signal-to-noise ratio (PSNR) of this method can enhance over 9 dB, and the total compression performance is improved greatly.
Institute of Scientific and Technical Information of China (English)
Jingwen Yan; Jiazhen Chen
2007-01-01
A new hyperspectral image compression method of spectral feature classification vector quantization (SFCVQ) and embedded zero-tree of wavelet (EZW) based on Karhunen-Loeve transformation (KLT) and integer wavelet transformation is represented. In comparison with the other methods, this method not only keeps the characteristics of high compression ratio and easy real-time transmission, but also has the advantage of high computation speed. After lifting based integer wavelet and SFCVQ coding are introduced, a system of nearly lossless compression of hyperspectral images is designed. KLT is used to remove the correlation of spectral redundancy as one-dimensional (1D) linear transform, and SFCVQ coding is applied to enhance compression ratio. The two-dimensional (2D) integer wavelet transformation is adopted for the decorrelation of 2D spatial redundancy. EZW coding method is applied to compress data in wavelet domain. Experimental results show that in comparison with the method of wavelet SFCVQ (WSFCVQ),the method of improved BiBlock zero tree coding (IBBZTC) and the method of feature spectral vector quantization (FSVQ), the peak signal-to-noise ratio (PSNR) of this method can enhance over 9 dB, and the total compression performance is improved greatly.
New environment-compatible heat-power plant Moabit with circulating fluidized-bed combustion
Energy Technology Data Exchange (ETDEWEB)
Bade, H.; Kuenisch, H.J.
1987-06-09
The authors report on the optimal utilisation of a city location for generating power and heat in a heat-power plant using circulating atmospheric fluidized-bed combustion. Because fluidized-bed combustion eliminates the need for secondary flue gas scrubbing equipment, the construction is highly compact. Also, this type of plant produces no waste water, so there is no disposal problem. Taking all aspects into consideration, circulating fluidized-bed combustion is especially interesting for heat-power plants in municipal areas with electrical block outputs of between 100 and 200 MW.
[Transforming health systems based on primary care].
Durán-Arenas, Luis; Salinas-Escudero, Guillermo; Granados-García, Víctor; Martínez-Valverde, Silvia
2012-01-01
Access to health services is a social basic determinant of health in Mexico unlike what happens in developed countries. The demand for health services is focused on primary care, but the design meets only the supply of hospital care services. So it generates a dissonance between the needs and the effective design of health services. In addition, the term affiliation refers to population contributing or in the recruitment process, that has been counted as members of these social security institutions (SS) and Popular Insurance (SP). In the case of Instituto Mexicano del Seguro Social (IMSS) three of four contributors are in contact with health services; while in the SP, this indicator does not exist. Moreover, the access gap between health services is found in the health care packages so that members of the SS and SP do not have same type of coverage. The question is: which model of health care system want the Mexicans? Primary care represents the first choice for increasing the health systems performance, as well as to fulfill their function of social protection: universal access and coverage based on needs, regardless whether it is a public or private health insurance. A central aspect for development of this component is the definition of the first contact with the health system through the creation of a primary health care team, led by a general practitioner as the responsible of a multidisciplinary health team. The process addresses the concepts of primary care nursing, consumption of inputs (mainly medical drugs), maintenance and general services. Adopting a comprehensive strategy that will benefit all Mexicans equally and without discrimination, this primary care system could be financed with a total operating cost of approximately $ 22,809 million by year.
Community-Based Ecotourism: The Transformation of Local Community
Directory of Open Access Journals (Sweden)
Pookhao Nantira
2014-01-01
Full Text Available Community-based ecotourism (CBET is considered a sustainable form of tourism that improves the quality of life of hosts at the tourist destination. Scholars have yet to explore the long-term operation of CBET in relation to its effects on the local way of life. Consequently, the purpose of this paper is to examine the transformation of a local community due to the operation of CBET in relation to sociocultural, economic and environmental aspects. The findings reveal that the community encounters both positive and negative impacts of transformation. However, unintended impacts of the CBET operation lay embedded in the transformation of relationships among the community members. The study identifies that close relationships among the villagers has been initially transformed to loose relationships due to forgotten communal goals; CBET has transformed from being a conservation tool to being a business-oriented goal which causes conflicts of interest among local people and alters traditional social structure. The study also agrees with the notion of social exchange theory for villagers to enhance environmental sustainability, and proposes that slight inequalities of benefits received from CBET causes social transformation at the local level.
Wavelet and ANN Based Relaying for Power Transformer Protection
Directory of Open Access Journals (Sweden)
S. Sudha
2007-01-01
Full Text Available This paper presents an efficient wavelet and neural network (WNN based algorithm for distinguishing magnetizing inrush currents from internal fault currents in three phase power transformers. The wavelet transform is applied first to decompose the current signals of the power transformer into a series of detailed wavelet components. The values of the detailed coefficients obtained can accurately discriminate between an internal fault and magnetizing inrush currents in power transformers. The detailed coefficients are further used to train an Artificial Neural Network (ANN. The trained ANN clearly distinguishes an internal fault current from magnetizing inrush current. A typical 750 MVA, 27/420KV, ∆/Y power transformer connected between a 27KV source at the sending end and a 420KV transmission line connected to an infinite bus power system at the receiving end were simulated using PSCAD/EMTDC software. The generated data were used by the MATLAB software to test the performance of the proposed technique. The simulation results obtained show that the new algorithm is more reliable and accurate. It provides a high operating sensitivity for internal faults and remains stable for inrush currents of the power transformers.
Futagami, Shiho
2000-01-01
This paper discusses the possibility of the transformation of North Korean socialistic companies. In this paper, three possible future scenarios concerning North Korean companies are presented. The first one is based on the traditional trend which you have seen already. In this scenario, North Korea will keep the principle of national self-reliance and realize the autarky. It will not have a big impact on Northeast Asian economies. The possibility for such a scenario is low, because of the da...
Curvelet Transform-Based Denoising Method for Doppler Frequency Extraction
Institute of Scientific and Technical Information of China (English)
HOU Shu-juan; WU Si-liang
2007-01-01
A novel image denoising method based on curvelet transform is proposed in order to improve the performance of Doppler frequency extraction in low signal-noise-ratio (SNR) environment. The echo can be represented as a gray image with spectral intensity as its gray values by time-frequency transform. And the curvelet coefficients of the image are computed. Then an adaptive soft-threshold scheme based on dual-median operation is implemented in curvelet domain. After that, the image is reconstructed by inverse curvelet transform and the Doppler curve is extracted by a curve detection scheme. Experimental results show the proposed method can improve the detection of Doppler frequency in low SNR environment.
Face Recognition Algorithms Based on Transformed Shape Features
Directory of Open Access Journals (Sweden)
Sambhunath Biswas
2012-05-01
Full Text Available Human face recognition is, indeed, a challenging task, especially under illumination and pose variations. We examine in the present paper effectiveness of two simple algorithms using coiflet packet and Radon transforms to recognize human faces from some databases of still gray level images, under the environment of illumination and pose variations. Both the algorithms convert 2-D gray level training face images into their respective depth maps or physical shape which are subsequently transformed by Coiflet packet and Radon transforms to compute energy for feature extraction. Experiments show that such transformed shape features are robust to illumination and pose variations. With the features extracted, training classes are optimally separated through linear discriminant analysis (LDA, while classification for test face images is made through a k-NN classifier, based on L1 norm and Mahalanobis distance measures. Proposed algorithms are then tested on face images that differ in illumination,expression or pose separately, obtained from three databases,namely, ORL, Yale and Essex-Grimace databases. Results, so obtained, are compared with two different existing algorithms.Performance using Daubechies wavelets is also examined. It is seen that the proposed Coiflet packet and Radon transform based algorithms have significant performance, especially under different illumination conditions and pose variation. Comparison shows the proposed algorithms are superior.
Feedback control of plasma density and heating power for steady state operation in LHD
Energy Technology Data Exchange (ETDEWEB)
Kamio, Shuji, E-mail: kamio@nifs.ac.jp; Kasahara, Hiroshi; Seki, Tetsuo; Saito, Kenji; Seki, Ryosuke; Nomura, Goro; Mutoh, Takashi
2015-12-15
Highlights: • We upgraded a control system for steady state operation in LHD. • This system contains gas fueling system and ICRF power control system. • Automatic power boost system is also attached for stable operation. • As a result, we achieved the long pulse up to 48 min in the electron density of more than 1 × 10{sup 19} m{sup −3}. - Abstract: For steady state operation, the feedback control of plasma density and heating power system was developed in the Large Helical Device (LHD). In order to achieve a record of the long pulse discharge, stable plasma density and heating power are needed. This system contains the radio frequency (RF) heating power control, interlocks, gas fueling, automatic RF phase control, ion cyclotron range of frequency (ICRF) antenna position control, and graphical user interface (GUI). Using the density control system, the electron density was controlled to the target density and using the RF heating power control system, the RF power injection could be stable. As a result of using this system, we achieved the long pulse up to 48 min in the electron density of more than 1 × 10{sup 19} m{sup −3}. Further, the ICRF hardware experienced no critical accidents during the 17th LHD experiment campaign in 2013.
Program Transformation to Identify List-Based Parallel Skeletons
Directory of Open Access Journals (Sweden)
Venkatesh Kannan
2016-07-01
Full Text Available Algorithmic skeletons are used as building-blocks to ease the task of parallel programming by abstracting the details of parallel implementation from the developer. Most existing libraries provide implementations of skeletons that are defined over flat data types such as lists or arrays. However, skeleton-based parallel programming is still very challenging as it requires intricate analysis of the underlying algorithm and often uses inefficient intermediate data structures. Further, the algorithmic structure of a given program may not match those of list-based skeletons. In this paper, we present a method to automatically transform any given program to one that is defined over a list and is more likely to contain instances of list-based skeletons. This facilitates the parallel execution of a transformed program using existing implementations of list-based parallel skeletons. Further, by using an existing transformation called distillation in conjunction with our method, we produce transformed programs that contain fewer inefficient intermediate data structures.
Piezoelectric transformer based power converters; design and control
DEFF Research Database (Denmark)
Rødgaard, Martin Schøler
The last two decades of research into piezoelectric transformer (PT) based power converters have led to some extensive improvements of the technology, but it still struggles to get its commercial success. This calls for further research and has been the subject of this work, in order to enable...
Optical correlation based on the fractional Fourier transform.
Granieri, S; Arizaga, R; Sicre, E E
1997-09-10
Some properties of optical correlation based on the fractional Fourier transform are analyzed. For a particular set of fractional orders, a filter is obtained that becomes insensitive to scale variations of the object. An optical configuration is also proposed to carry out the fractional correlation in a flexible way, and some experimental results are shown.
Exploring Phonetic Realization in Danish by Transformation-Based Learning
DEFF Research Database (Denmark)
Uneson, Marcus; Schachtenhaufen, Ruben
2011-01-01
We align phonemic and semi-narrow phonetic transcriptions in the DanPASS corpus and extend the phonemic description with sound classes and with traditional phonetic features. From this representation, we induce rules for phonetic realization by Transformation-Based Learning (TBL). The rules thus...
An efficient visual saliency detection model based on Ripplet transform
Indian Academy of Sciences (India)
A DIANA ANDRUSHIA; R THANGARAJAN
2017-05-01
Even though there have been great advancements in computer vision tasks, the development of human visual attention models is still not well investigated. In day-to-day life, one can find ample applications of saliency detection in image and video processing. This paper presents an efficient visual saliency detectionmodel based on Ripplet transform, which aims at detecting the salient region and achieving higher Receiver Operating Characteristics (ROC). Initially the feature maps are obtained from Ripplet transform in different scales and different directions of the image. The global and local saliency maps are computed based on the global probability density distribution and feature distribution of local areas, which are combined together to get the final saliency map. Ripplet-transform-based visual saliency detection is the novel approach carried out in this paper. Experimental results indicate that the proposed method based on Ripplet transformation can give excellent performance in terms of precision, recall, F measure and Mean Absolute Error (MAE), and is compared with 10 state-of-the-art methods on five benchmark datasets.
Stego Optical Encryption Based on Chaotic Baker's Map Transformation
Hussain, Iqtadar; Gondal, Muhammad Asif
2014-06-01
In this article, an optical image encryption algorithm based on chaotic baker's map is presented. The stego-image is encrypted with the help of double random phase encoding algorithm and then produced disorder with the help of chaotic transformation. Security test shows that the reading of proposed algorithm is very close to the optimal values.
FAST TEXT LOCATION BASED ON DISCRETE WAVELET TRANSFORM
Institute of Scientific and Technical Information of China (English)
Li Xiaohua; Shen Lansun
2005-01-01
The paper describes a texture-based fast text location scheme which operates directly in the Discrete Wavelet Transform (DWT) domain. By the distinguishing texture characteristics encoded in wavelet transform domain, the text is fast detected from complex background images stored in the compressed format such as JPEG2000 without full decompress. Compared with some traditional character location methods, the proposed scheme has the advantages of low computational cost, robust to size and font of characters and high accuracy. Preliminary experimental results show that the proposed scheme is efficient and effective.
Spindle extraction method for ISAR image based on Radon transform
Wei, Xia; Zheng, Sheng; Zeng, Xiangyun; Zhu, Daoyuan; Xu, Gaogui
2015-12-01
In this paper, a method of spindle extraction of target in inverse synthetic aperture radar (ISAR) image is proposed which depends on Radon Transform. Firstly, utilizing Radon Transform to detect all straight lines which are collinear with these line segments in image. Then, using Sobel operator to detect image contour. Finally, finding all intersections of each straight line and image contour, the two intersections which have maximum distance between them is the two ends of this line segment and the longest line segment of all line segments is spindle of target. According to the proposed spindle extraction method, one hundred simulated ISAR images which are respectively rotated 0 degrees, 10 degrees, 20 degrees, 30 degrees and 40 degrees in counterclockwise are used to do experiment and the proposed method and the detection results are more close to the real spindle of target than the method based on Hough Transform .
Ultrafast ranging lidar based on real-time Fourier transformation.
Xia, Haiyun; Zhang, Chunxi
2009-07-15
Real-time Fourier-transformation-based ranging lidar using a mode-locked femtosecond fiber laser is demonstrated. The object signal and the reference signal are guided from a fiber Mach-Zehnder interferometer into a dispersive element. The two optical pulses extend and overlap with each other temporally, which yields a microwave pulse on the photodetector with its frequency proportional to the time delay between the two signals. The temporal interferograms are transformed from the time domain into the frequency domain using a time-to-frequency conversion function obtained in the calibration process. The Fourier transform is used in the data processing. A range resolution of 334 nm at a sampling rate of 48.6 MHz over a distance of 16 cm is demonstrated in the laboratory.
Regression based peak load forecasting using a transformation technique
Energy Technology Data Exchange (ETDEWEB)
Haida, Takeshi; Muto, Shoichi (Tokyo Electric Power Co. (Japan). Computer and Communication Research Center)
1994-11-01
This paper presents a regression based daily peak load forecasting method with a transformation technique. In order to forecast the load precisely through a year, the authors should consider seasonal load change, annual load growth and the latest daily load change. To deal with these characteristics in the load forecasting, a transformation technique is presented. This technique consists of a transformation function with translation and reflection methods. The transformation function is estimated with the previous year's data points, in order that the function converts the data points into a set of new data points with preserving the shape of temperature-load relationships in the previous year. Then, the function is slightly translated so that the transformed data points will fit the shape of temperature-load relationships in the year. Finally, multivariate regression analysis with the latest daily loads and weather observations estimates the forecasting model. Large forecasting errors caused by the weather-load nonlinear characteristic in the transitional seasons such as spring and fall are reduced. Performance of the technique which is verified with simulations on actual load data of Tokyo Electric Power Company is also described.
Tensor product model transformation based decoupled terminal sliding mode control
Zhao, Guoliang; Li, Hongxing; Song, Zhankui
2016-06-01
The main objective of this paper is to propose a tensor product model transformation based decoupled terminal sliding mode controller design methodology. The methodology is divided into two steps. In the first step, tensor product model transformation is applied to the single-input-multi-output system and a parameter-varying weighted linear time-invariant system is obtained. Then, decoupled terminal sliding mode controller is designed based on the linear time-invariant systems. The main novelty of this paper is that the nonsingular terminal sliding mode control design is based on a numerical model rather than an analytical one. Finally, simulations are tested on cart-pole system and translational oscillations with a rotational actuator system.
Fingerprint Image Segmentation Algorithm Based on Contourlet Transform Technology
Directory of Open Access Journals (Sweden)
Guanghua Zhang
2016-09-01
Full Text Available This paper briefly introduces two classic algorithms for fingerprint image processing, which include the soft threshold denoise algorithm of wavelet domain based on wavelet domain and the fingerprint image enhancement algorithm based on Gabor function. Contourlet transform has good texture sensitivity and can be used for the segmentation enforcement of the fingerprint image. The method proposed in this paper has attained the final fingerprint segmentation image through utilizing a modified denoising for a high-frequency coefficient after Contourlet decomposition, highlighting the fingerprint ridge line through modulus maxima detection and finally connecting the broken fingerprint line using a value filter in direction. It can attain richer direction information than the method based on wavelet transform and Gabor function and can make the positioning of detailed features more accurate. However, its ridge should be more coherent. Experiments have shown that this algorithm is obviously superior in fingerprint features detection.
DEFF Research Database (Denmark)
Østergaard, Dorte Skaarup; Svendsen, Svend
2016-01-01
Danish single-family houses constructed in the 1900s were estimated based on simple steady-state calculations. We found that the radiators in existing single-family houses should not necessarilrbe expected to be over-dimensioned compared to current design heat loss. However, there is considerable...... in typical Danish single-family houses constructed in the 1900s. The study provides a simplified theoretical overview of typical building constructions and standards for the calculation of design heat loss and design heating power in Denmark in the 1900s. The heating power and heating demand in six typical...... potential for using low-temperature space heating in existing single-family houses in typical operation conditions. Older houses were not always found to require higher heating system temperatures than newer houses. We found that when these houses have gone through reasonable energy renovations, most...
ECG Analysis based on Wavelet Transform and Modulus Maxima
Directory of Open Access Journals (Sweden)
Mourad Talbi
2012-01-01
Full Text Available In this paper, we have developed a new technique of P, Q, R, S and T Peaks detection using Wavelet Transform (WT and Modulus maxima. One of the commonest problems in electrocardiogram (ECG signal processing, is baseline wander removal suppression. Therefore we have removed the baseline wander in order to make easier the detection of the peaks P and T. Those peaks are detected after the QRS detection. The proposed method is based on the application of the discritized continuous wavelet transform (Mycwt used for the Bionic wavelet transform, to the ECG signal in order to detect R-peaks in the first stage and in the second stage, the Q and S peaks are detected using the R-peaks localization. Finally the Modulus maxima are used in the undecimated wavelet transform (UDWT domain in order to detect the others peaks (P, T. This detection is performed by using a varying-length window that is moving along the whole signal. For evaluating the proposed method, we have compared it to others techniques based on wavelets. In this evaluation, we have used many ECG signals taken from MIT-BIH database. The obtained results show that the proposed method outperforms a number of conventional techniques used for our evaluation.
Radiotoxicity and decay heat power of spent nuclear fuel of VVER type reactors at long-term storage.
Bergelson, B R; Gerasimov, A S; Tikhomirov, G V
2005-01-01
Radiotoxicity and decay heat power of the spent nuclear fuel of VVER-1000 type reactors are calculated during storage time up to 300,000 y. Decay heat power of radioactive waste (radwaste) determines parameters of the heat removal system for the safe storage of spent nuclear fuel. Radiotoxicity determines the radiological hazard of radwaste after its leakage and penetration into the environment.
A Quaternionic Wavelet Transform-based Approach for Object Recognition
Directory of Open Access Journals (Sweden)
R. Ahila Priyadharshini
2014-07-01
Full Text Available Recognizing the objects in complex natural scenes is the challenging task as the object may be occluded, may vary in shape, position and in size. In this paper a method to recognize objects from different categories of images using quaternionic wavelet transform (QWT is presented. This transform separates the information contained in the image better than a traditional Discrete wavelet transform and provides a multiscale image analysis whose coefficients are 2D analytic, with one near-shift invariant magnitude and three phases. The two phases encode local image shifts and the third one contains texture information. In the domain of object recognition, it is often to classify objects from images that make only limited part of the image. Hence to identify local features and certain region of images, patches are extracted over the interest points detected from the original image using Wavelet based interest point detector. Here QWT magnitude and phase features are computed for every patch. Then these features are trained, tested and classified using SVM classifier in order to have supervised learning model. In order to compare the performance of local feature with global feature, the transform is applied to the entire image and the global features are derived. The performance of QWT is compared with discrete wavelet transform (DWT and dual tree discrete wavelet transform (DTDWT. Observations revealed that QWT outperforms the DWT and shift invariant DTDWT with lesser equal error rate. The experimental evaluation is done using the complex Graz databases.Defence Science Journal, Vol. 64, No. 4, July 2014, pp. 350-357, DOI:http://dx.doi.org/10.14429/dsj.64.4503
Energy Technology Data Exchange (ETDEWEB)
Nohlgren, Ingrid; Gunnarsson, Emma; Lundqvist, Per; Stigander, Haakan; Widmark, Annika (AaF, Stockholm (Sweden))
2012-02-15
During the last 5-10 years, research and development efforts have been made in the field of polygeneration of heat and power with production of 'other green' products such as transport fuels or wood pellets. The driving force for heat and power producers is the potential of increased profitability through additional sales of heat. The driving force for wood pellet and some transport fuel producers is the potential of low cost process steam or heat. However, in the case of gasification based transport fuel production processes the situation is different. The process generates a surplus of heat, which can benefit from the proximity of a district heating net. In addition, some polygeneration combinations could provide other advantages such as more efficient raw material handling. Together with these driving forces, the EU renewable energy directive (which targets 10 % renewable energy use in the transport sector by 2020), shows that the market for production of renewable transport fuel is expanding. To refine Swedish biomass resources to more highly valuable products such as wood pellets or renewable transport fuels would maintain industry and employment opportunities within Sweden and at the same time fulfils the international and national climate targets. The overall aim with this project is to describe the factors which are crucial for the opportunity for profitable polygeneration of heat, power and wood pellets or renewable transport fuels and how these factors influence the location of such a plant within Sweden. The important factors can be categorized as: (1) Supply of raw material, (2) distribution of raw material and products, (3) Demand of products and (4) Integration between the different plants. In this project, only general aspects are described and should be seen as guidance for the industry (both energy and forest industry) which has an interest in polygeneration. The project gives an overview of different possibilities, opportunities and
Image encryption techniques based on the fractional Fourier transform
Hennelly, B. M.; Sheridan, J. T.
2003-11-01
The fractional Fourier transform, (FRT), is a generalisation of the Fourier transform which allows domains of mixed spatial frequency and spatial information to be examined. A number of method have recently been proposed in the literature for the encryption of two dimensional information using optical systems based on the FRT. Typically, these methods require random phase screen keys to decrypt the data, which must be stored at the receiver and must be carefully aligned with the received encrypted data. We have proposed a new technique based on a random shifting or Jigsaw transformation. This method does not require the use of phase keys. The image is encrypted by juxtaposition of sections of the image in various FRT domains. The new method has been compared numerically with existing methods and shows comparable or superior robustness to blind decryption. An optical implementation is also proposed and the sensitivity of the various encryption keys to blind decryption is quantified. We also present a second image encryption technique, which is based on a recently proposed method of optical phase retrieval using the optical FRT and one of its discrete counterparts. Numerical simulations of the new algorithm indicates that the sensitivity of the keys is much greater than any of the techniques currently available. In fact the sensitivity appears to be so high that optical implementation, based on existing optical signal processing technology, may be impossible. However, the technique has been shown to be a powerful method of 2-D image data encryption.
Fourier transform spectrometer based on Fabry-Perot interferometer.
Al-Saeed, Tarek A; Khalil, Diaa A
2016-07-10
We analyze the Fourier transform spectrometer based on a symmetric/asymmetric Fabry-Perot interferometer. In this spectrometer, the interferogram is obtained by recording the intensity as a function of the interferometer length. Then, we recover the spectrum by applying the discrete Fourier transform (DFT) directly on the interferogram. This technique results in spectral harmonic overlap and fictitious wavenumber components outside the original spectral range. For this purpose, in this work, we propose a second method to recover the spectrum. This method is based on expanding the DFT of the interferogram and the spectrum by a Haar or box function. By this second method, we recovered the spectrum and got rid of the fictitious spectral components and spectral harmonic overlap.
Method of Infrared Image Enhancement Based on Stationary Wavelet Transform
Institute of Scientific and Technical Information of China (English)
QI Fei; LI Yan-jun; ZHANG Ke
2008-01-01
Aiming at the problem, i.e. infrared images own the characters of bad contrast ratio and fuzzy edges, a method to enhance the contrast of infrared image is given, which is based on stationary wavelet transform. After making stationary wavelet transform to an infrared image, denoising is done by the proposed method of double-threshold shrinkage in detail coefficient matrixes that have high noisy intensity. For the approximation coefficient matrix with low noisy intensity, enhancement is done by the proposed method based on histogram. The enhanced image can be got by wavelet coefficient reconstruction. Furthermore, an evaluation criterion of enhancement performance is introduced. The results show that this algorithm ensures target enhancement and restrains additive Gauss white noise effectively. At the same time, its amount of calculation is small and operation speed is fast.
A geometric transformation to protect minutiae-based fingerprint templates
Sutcu, Yagiz; Sencar, Husrev T.; Memon, Nasir
2007-04-01
The increasing use of biometrics in different environments presents new challenges. Most importantly, biometric data are irreplaceable. Therefore, storing biometric templates, which is unique to individual user, entails significant security risks. In this paper, we propose a geometric transformation for securing the minutiae based fingerprint templates. The proposed scheme employs a robust one-way transformation that maps geometrical configuration of the minutiae points into a fixed-length code vector. This representation enables efficient alignment and reliable matching. Experiments are conducted by applying the proposed method on a synthetically generated minutiae point sets. Preliminary results show that the proposed scheme provides a simple and effective solution to the template security problem of the minutiae based fingerprint.
Matrix-Vector Based Fast Fourier Transformations on SDR Architectures
Directory of Open Access Journals (Sweden)
Y. He
2008-05-01
Full Text Available Today Discrete Fourier Transforms (DFTs are applied in various radio standards based on OFDM (Orthogonal Frequency Division Multiplex. It is important to gain a fast computational speed for the DFT, which is usually achieved by using specialized Fast Fourier Transform (FFT engines. However, in face of the Software Defined Radio (SDR development, more general (parallel processor architectures are often desirable, which are not tailored to FFT computations. Therefore, alternative approaches are required to reduce the complexity of the DFT. Starting from a matrix-vector based description of the FFT idea, we will present different factorizations of the DFT matrix, which allow a reduction of the complexity that lies between the original DFT and the minimum FFT complexity. The computational complexities of these factorizations and their suitability for implementation on different processor architectures are investigated.
Saturation Detection-Based Blocking Scheme for Transformer Differential Protection
Directory of Open Access Journals (Sweden)
Byung Eun Lee
2014-07-01
Full Text Available This paper describes a current differential relay for transformer protection that operates in conjunction with a core saturation detection-based blocking algorithm. The differential current for the magnetic inrush or over-excitation has a point of inflection at the start and end of each saturation period of the transformer core. At these instants, discontinuities arise in the first-difference function of the differential current. The second- and third-difference functions convert the points of inflection into pulses, the magnitudes of which are large enough to detect core saturation. The blocking signal is activated if the third-difference of the differential current is larger than the threshold and is maintained for one cycle. In addition, a method to discriminate between transformer saturation and current transformer (CT saturation is included. The performance of the proposed blocking scheme was compared with that of a conventional harmonic blocking method. The test results indicate that the proposed scheme successfully discriminates internal faults even with CT saturation from the magnetic inrush, over-excitation, and external faults with CT saturation, and can significantly reduce the operating time delay of the relay.
Magnetic suspension based Fourier Transform Infrared Spectrometer mechanism (FTIS)
Köker, Ingo; Langenbach, Harald; Schmid, Manfred; Lautier, Jean-Michel
2005-07-01
In the frame of an ESTEC technology contract the development of a Magnetically Suspended Fourier Transform Spectrometer Mechanism (FTIS) was carried out. The aim of the development is to avoid the issues found in mechanically suspended systems and to provide an active alignment and disturbance rejection capability for spectrometer applications. In the frame of FTIS an actively controlled suspension system based on the use of magnetic bearings was defined, developed and built as a demonstration model.
Directory of Open Access Journals (Sweden)
Shuo-Tsung Chen
2015-01-01
Full Text Available Purpose. Most applications in the field of medical image processing require precise estimation. To improve the accuracy of segmentation, this study aimed to propose a novel segmentation method for coronary arteries to allow for the automatic and accurate detection of coronary pathologies. Methods. The proposed segmentation method included 2 parts. First, 3D region growing was applied to give the initial segmentation of coronary arteries. Next, the location of vessel information, HHH subband coefficients of the 3D DWT, was detected by the proposed vessel-texture discrimination algorithm. Based on the initial segmentation, 3D DWT integrated with the 3D neutrosophic transformation could accurately detect the coronary arteries. Results. Each subbranch of the segmented coronary arteries was segmented correctly by the proposed method. The obtained results are compared with those ground truth values obtained from the commercial software from GE Healthcare and the level-set method proposed by Yang et al., 2007. Results indicate that the proposed method is better in terms of efficiency analyzed. Conclusion. Based on the initial segmentation of coronary arteries obtained from 3D region growing, one-level 3D DWT and 3D neutrosophic transformation can be applied to detect coronary pathologies accurately.
E-Business Transformation: An Analysis Framework Based on Critical Organizational Dimensions
Institute of Scientific and Technical Information of China (English)
ZENG Qingfeng; CHEN Wenbo; HUANG Lihua
2008-01-01
In the era of Internet economics, e-business has become one of the most important strategic factors for enterprise development, so theoretical systems are needed to help enterprises develop e-business transformation strategies. A review of enterprise transformation theory identified five critical organization dimensions of e-business transformation, corporate strategy and vision transformation, organizational structure, product and market transformation, business process transformation, and corporate culture transformation. An e-business transformation process model was developed based on the five dimensions. This model can help enterprises to more effectively implement e-business transformation strategies.
Stereo matching based on census transformation of image gradients
Stentoumis, C.; Grammatikopoulos, L.; Kalisperakis, I.; Karras, G.; Petsa, E.
2015-05-01
Although multiple-view matching provides certain significant advantages regarding accuracy, occlusion handling and radiometric fidelity, stereo-matching remains indispensable for a variety of applications; these involve cases when image acquisition requires fixed geometry and limited number of images or speed. Such instances include robotics, autonomous navigation, reconstruction from a limited number of aerial/satellite images, industrial inspection and augmented reality through smart-phones. As a consequence, stereo-matching is a continuously evolving research field with growing variety of applicable scenarios. In this work a novel multi-purpose cost for stereo-matching is proposed, based on census transformation on image gradients and evaluated within a local matching scheme. It is demonstrated that when the census transformation is applied on gradients the invariance of the cost function to changes in illumination (non-linear) is significantly strengthened. The calculated cost values are aggregated through adaptive support regions, based both on cross-skeletons and basic rectangular windows. The matching algorithm is tuned for the parameters in each case. The described matching cost has been evaluated on the Middlebury stereo-vision 2006 datasets, which include changes in illumination and exposure. The tests verify that the census transformation on image gradients indeed results in a more robust cost function, regardless of aggregation strategy.
Natural frequencies and damping estimation based on continuous wavelet transform
Institute of Scientific and Technical Information of China (English)
DAI Yu; SUN He-yi; LI Hui-peng; TANG Wen-yan
2008-01-01
The continuous wavelet transform (CWT) based method was improved for estimating the natural fre-quencies and damping ratios of a structural system in this paper. The appropriate scale of CWT was selected by means of the least squares method to identify the systems with closely spaced modes. The important issues relat-ed to estimation accuracy such as mode separation and end effect, were also investigated. These issues were as-sociated with the parameter selection of wavelet function based on the fitting error of least squares. The efficien-cy of the method was confirmed by applying it to a simulated 3dof damped system with two close modes.
New Blocking Artifacts Reduction Method Based on Wavelet Transform
Institute of Scientific and Technical Information of China (English)
SHI Min; YI Qing-ming
2007-01-01
It is well known that a block discrete cosine transform compressed image exhibits visually annoying blocking artifacts at low-bit-rate. A new post-processing deblocking algorithm in wavelet domain is proposed. The algorithm exploits blocking-artifact features shown in wavelet domain. The energy of blocking artifacts is concentrated into some lines to form annoying visual effects after wavelet transform. The aim of reducing blocking artifacts is to capture excessive energy on the block boundary effectively and reduce it below the visual scope. Adaptive operators for different subbands are computed based on the wavelet coefficients. The operators are made adaptive to different images and characteristics of blocking artifacts. Experimental results show that the proposed method can significantly improve the visual quality and also increase the peak signal-noise-ratio(PSNR) in the output image.
Analytic discrete cosine harmonic wavelet transform based OFDM system
Indian Academy of Sciences (India)
M N Suma; S V Narasimhan; B Kanmani
2015-02-01
An OFDM based on Analytic Discrete Cosine HarmonicWavelet Transform (ADCHWT_OFDM) has been proposed in this paper. Analytic DCHWT has been realized by applying DCHWT to the original signal and to its Hilbert transform. ADCHWT has been found to be computationally efficient and very effective in improving Bit Error Rate (BER) and Peak to Average Power Ratio (PAPR) performance. Improvement compared to that of Haar-WT OFDM and DFT OFDM is achieved without employing Cyclic Prefix BER is 0.002 for ADCHWT OFDM compared to Haar WT, DFT OFDM which have BER of 0.06 and 0.4, respectively, at 15 dB SNR. PAPR is also reduced by 3 dB compared to DFT OFDM and 0.3 dB reduction compared to Haar WT OFDM.
View Transformation Based on a Single Outdoor Image
Directory of Open Access Journals (Sweden)
Shi-Hui Zhang
2013-05-01
Full Text Available Abstract An automatic approach for view transformation based on a single outdoor image is proposed in this paper. First, the hierarchical segmentation method is conducted to segment an outdoor image into several meaningful regions and each region is labelled as sky, ground or standing object. Then, different methods are used to estimate each region's depth according to its label. After that, the obtained depth information is utilized to create a new view image after any rotation, translation and pitch. Finally, the image inpainting work for the missing colour region is accomplished using its neighbour's colour. Extensive experiments show the proposed approach not only improves the accuracy of view transformation, but also performs well even for images with occlusion phenomena.
Towards discrete wavelet transform-based human activity recognition
Khare, Manish; Jeon, Moongu
2017-06-01
Providing accurate recognition of human activities is a challenging problem for visual surveillance applications. In this paper, we present a simple and efficient algorithm for human activity recognition based on a wavelet transform. We adopt discrete wavelet transform (DWT) coefficients as a feature of human objects to obtain advantages of its multiresolution approach. The proposed method is tested on multiple levels of DWT. Experiments are carried out on different standard action datasets including KTH and i3D Post. The proposed method is compared with other state-of-the-art methods in terms of different quantitative performance measures. The proposed method is found to have better recognition accuracy in comparison to the state-of-the-art methods.
Wavelet transform based ECG signal filtering implemented on FPGA
Directory of Open Access Journals (Sweden)
Germán-Salló Zoltán
2011-12-01
Full Text Available Filtering electrocardiographic (ECG signals is always a challenge because the accuracy of their interpretation depends strongly on filtering results. The Discrete Wavelet Transform (DWT is an efficient, new and useful tool for signal processing applications and it’s adopted in many domains as biomedical signal filtering. This transform came about from different fields, including mathematics, physics and signal processing, it has a growing applicability due to its so-called multiresolution analyzing capabilities. FPGAs are reconfigurable logic devices made up of arrays of logic cells and routing channels having some specific characteristics which allow to use them in signal processing applications. This paper presents a DWT based ECG signal denoising method implemented on FPGA, using Matlab specific Xilinx tool, as System Generator, the procedure is simulated and evaluated through filtering specific parameters.
Pautomatic Sea Target Detection Based on Wavelet Transform
Institute of Scientific and Technical Information of China (English)
PEI Li-li; LUO Hai-bo
2009-01-01
An effective automatic target detection algorithm based on wavelet transform, which takes advantage of the localization and the orientation of wavelet analysis, is proposed. The algorithm detects the target in the vertical component of the wavelet transformation of the image. After mutual energy combination and sea clutter suppression through spatial weighting and thresholding, the target is located through maximum energy determination and its size is indicated through similarity measurement function of two overlapping windows. Experiment results show that the target can be detected by the algorithm in a single image frame and the better efficiency can be obtained also under the complicated backgrounds of existing the disturbances of cloud layer and fish scale light.
Optimization of integer wavelet transforms based on difference correlation structures.
Li, Hongliang; Liu, Guizhong; Zhang, Zhongwei
2005-11-01
In this paper, a novel lifting integer wavelet transform based on difference correlation structure (DCCS-LIWT) is proposed. First, we establish a relationship between the performance of a linear predictor and the difference correlations of an image. The obtained results provide a theoretical foundation for the following construction of the optimal lifting filters. Then, the optimal prediction lifting coefficients in the sense of least-square prediction error are derived. DCCS-LIWT puts heavy emphasis on image inherent dependence. A distinct feature of this method is the use of the variance-normalized autocorrelation function of the difference image to construct a linear predictor and adapt the predictor to varying image sources. The proposed scheme also allows respective calculations of the lifting filters for the horizontal and vertical orientations. Experimental evaluation shows that the proposed method produces better results than the other well-known integer transforms for the lossless image compression.
A Reversible Image Steganographic Algorithm Based on Slantlet Transform
Directory of Open Access Journals (Sweden)
Sushil Kumar
2013-07-01
Full Text Available In this paper we present a reversible imagesteganography technique based on Slantlet transform (SLTand using advanced encryption standard (AES method. Theproposed method first encodes the message using two sourcecodes, viz., Huffman codes and a self-synchronizing variablelength code known as, T-code. Next, the encoded binarystring is encrypted using an improved AES method. Theencrypted data so obtained is embedded in the middle andhigh frequency sub-bands, obtained by applying 2-level ofSLT to the cover-image, using thresholding method. Theproposed algorithm is compared with the existing techniquesbased on wavelet transform. The Experimental results showthat the proposed algorithm can extract hidden message andrecover the original cover image with low distortion. Theproposed algorithm offers acceptable imperceptibility,security (two-layer security and provides robustness againstGaussian and Salt-n-Pepper noise attack.
Time-frequency representation measurement based on temporal Fourier transformation
Suen, Yifan; Xiao, Shaoqiu; Hao, Sumin; Zhao, Xiaoxiang; Xiong, Yigao; Liu, Shenye
2016-10-01
We propose a new scheme to physically realize the short-time Fourier transform (STFT) of chirped optical pulse using time-lens array that enables us to get time-frequency representation without using FFT algorithm. The time-lens based upon the four-wave mixing is used to perform the process of temporal Fourier transformation. Pump pulse is used for both providing the quadratic phase and being the window function of STFT. The idea of STFT is physically realized in our scheme. Simulations have been done to investigate performance of the time-frequency representation scheme (TFRS) in comparison with STFT using FFT algorithm. Optimal measurement of resolution in time and frequency has been discussed.
Construction of Hilbert Transform Pairs of Wavelet Bases and Gabor-like Transforms
Chaudhury, Kunal Narayan
2009-01-01
We propose a novel method for constructing Hilbert transform (HT) pairs of wavelet bases based on a fundamental approximation-theoretic characterization of scaling functions--the B-spline factorization theorem. In particular, starting from well-localized scaling functions, we construct HT pairs of biorthogonal wavelet bases of L^2(R) by relating the corresponding wavelet filters via a discrete form of the continuous HT filter. As a concrete application of this methodology, we identify HT pairs of spline wavelets of a specific flavor, which are then combined to realize a family of complex wavelets that resemble the optimally-localized Gabor function for sufficiently large orders. Analytic wavelets, derived from the complexification of HT wavelet pairs, exhibit a one-sided spectrum. Based on the tensor-product of such analytic wavelets, and, in effect, by appropriately combining four separable biorthogonal wavelet bases of L^2(R^2), we then discuss a methodology for constructing 2D directional-selective complex...
Power Electronic Transformer based Three-Phase PWM AC Drives
Basu, Kaushik
A Transformer is used to provide galvanic isolation and to connect systems at different voltage levels. It is one of the largest and most expensive component in most of the high voltage and high power systems. Its size is inversely proportional to the operating frequency. The central idea behind a power electronic transformer (PET) also known as solid state transformer is to reduce the size of the transformer by increasing the frequency. Power electronic converters are used to change the frequency of operation. Steady reduction in the cost of the semiconductor switches and the advent of advanced magnetic materials with very low loss density and high saturation flux density implies economic viability and feasibility of a design with high power density. Application of PET is in generation of power from renewable energy sources, especially wind and solar. Other important application include grid tied inverters, UPS e.t.c. In this thesis non-resonant, single stage, bi-directional PET is considered. The main objective of this converter is to generate adjustable speed and magnitude pulse width modulated (PWM) ac waveforms from an ac or dc grid with a high frequency ac link. The windings of a high frequency transformer contains leakage inductance. Any switching transition of the power electronic converter connecting the inductive load and the transformer requires commutation of leakage energy. Commutation by passive means results in power loss, decrease in the frequency of operation, distortion in the output voltage waveform, reduction in reliability and power density. In this work a source based partially loss-less commutation of leakage energy has been proposed. This technique also results in partial soft-switching. A series of converters with novel PWM strategies have been proposed to minimize the frequency of leakage inductance commutation. These PETs achieve most of the important features of modern PWM ac drives including 1) Input power factor correction, 2) Common
Multifocus image fusion scheme based on nonsubsampled contourlet transform
Zhou, Xinxing; Wang, Dianhong; Duan, Zhijuan; Li, Dongming
2011-06-01
This paper proposes a novel multifocus image fusion scheme based on nonsubsampled contourlet transform (NSCT). The selection principles for different subband coefficients in NSCT domain are discussed in detail. In order to be consistent with the characteristics of the human visual system and improve the robustness of the fusion algorithm to the noise, the NSCT-DCT energy is first developed. Based on it, the clarity measure and bandpass energy contrast are defined and employed to motivate the pulse coupled neural networks (PCNN) for the fusion of lowpass and bandpass subbands, respectively. The performance of the proposed fusion scheme is assessed by experiments and the results demonstrate that the algorithm proposed in the paper compares favorably to wavelet-based, contourlet-based and NSCTbased fusion algorithms in terms of visual appearances and objective criterion.
AN EFFICIENT HILBERT AND INTEGER WAVELET TRANSFORM BASED VIDEO WATERMARKING
Directory of Open Access Journals (Sweden)
AGILANDEESWARI L.
2016-03-01
Full Text Available In this paper, an efficient, highly imperceptible, robust, and secure digital video watermarking technique for content authentication based on Hilbert transform in the Integer Wavelet Transform (IWT domain has been introduced. The Hilbert coefficients of gray watermark image are embedded into the cover video frames Hilbert coefficients on the 2-level IWT decomposed selected block on sub-bands using Principal Component Analysis (PCA technique. The authentication is achieved by using the digital signature mechanism. This mechanism is used to generate and embed a digital signature after embedding the watermarks. Since, the embedding process is done in Hilbert transform domain, the imperceptibility and the robustness of the watermark is greatly improved. At the receiver end, prior to the extraction of watermark, the originality of the content is verified through the authentication test. If the generated and received signature matches, it proves that the received content is original and performs the extraction process, otherwise deny the extraction process due to unauthenticated received content. The proposed method avoids typical degradations in the imperceptibility level of watermarked video in terms of Average Peak Signal – to – Noise Ratio (PSNR value of about 48db, while it is still providing better robustness against common video distortions such as frame dropping, averaging, and various image processing attacks such as noise addition, median filtering, contrast adjustment, and geometrical attacks such as, rotation and cropping in terms of Normalized Correlation Coefficient (NCC value of about nearly 1.
Iris Localization Algorithm Based on Improved Generalized Symmetry Transform
Institute of Scientific and Technical Information of China (English)
左坤隆; 刘文耀; 朱昊; 王晓东
2004-01-01
Accuracy and fastness of iris localization are very important in automatic iris recognition. A new fast iris localization algorithm based on improved generalized symmetry transform (GST) was proposed by utilizing iris symmetry. GST was improved in three aspects:1) A new distance weight function is defined. The new weight function, which is effective in iris localization, utilized the characteristic of irises that the iris is a circular object and it has one inner boundary and one outer boundary. 2) Each calculation of the symmetry measurement of a pair of symmetry points was performed by taking one point of a pair as the starting point of the transformation. This is the most important reason for fast iris localization,due to which, repetitious computation was largely excluded. 3) A new phase weight function was proposed to adjust GST to locate circle target much better because the inner part of iris is darker than the outer part. The edge map of iris image was acquired and GST was only implemented on the edge point, which decreased computation without loss of accuracy. The modification of distance weight function and phase weight function leads to the accuracy of localization, and other ideas speed up the localization. Experiments show that the average speed of new algorithm is about 7.0-8.5 times as high as traditional ones including integro-differential operator and Hough transform method.
Digital Watermarking Algorithm Based on Wavelet Transform and Neural Network
Institute of Scientific and Technical Information of China (English)
WANG Zhenfei; ZHAI Guangqun; WANG Nengchao
2006-01-01
An effective blind digital watermarking algorithm based on neural networks in the wavelet domain is presented. Firstly, the host image is decomposed through wavelet transform. The significant coefficients of wavelet are selected according to the human visual system (HVS) characteristics. Watermark bits are added to them. And then effectively cooperates neural networks to learn the characteristics of the embedded watermark related to them. Because of the learning and adaptive capabilities of neural networks, the trained neural networks almost exactly recover the watermark from the watermarked image. Experimental results and comparisons with other techniques prove the effectiveness of the new algorithm.
Digital differential confocal microscopy based on spatial shift transformation.
Liu, J; Wang, Y; Liu, C; Wilson, T; Wang, H; Tan, J
2014-11-01
Differential confocal microscopy is a particularly powerful surface profilometry technique in industrial metrology due to its high axial sensitivity and insensitivity to noise. However, the practical implementation of the technique requires the accurate positioning of point detectors in three-dimensions. We describe a simple alternative based on spatial transformation of a through-focus series of images obtained from a homemade beam scanning confocal microscope. This digital differential confocal microscopy approach is described and compared with the traditional Differential confocal microscopy approach. The ease of use of the digital differential confocal microscopy system is illustrated by performing measurements on a 3D standard specimen.
A study of Hough Transform-based fingerprint alignment algorithms
CSIR Research Space (South Africa)
Mlambo, CS
2014-10-01
Full Text Available array. In 2013 Paulino et al [10] applied Ratha et al’s [2] approach in latent fingerprint matching to present a descriptor-based Hough transform. This involved the use of orientation field and minutiae information to accumulate evidence into accumulator... and improves on the early work presented in the 1990’s, as presented in [5], [14], [8], [17], [11], [10], and [12]. As a result, the memory requirements, computing time and performance on different conditions of minutiae points has not been presented...
Six transformer based asymmetrical embedded Z-source inverters
DEFF Research Database (Denmark)
Wei, Mo; Poh Chiang, Loh; Chi, Jin
2013-01-01
Embedded/Asymmetrical embedded Z-source inverters were proposed to maintain smooth input current/voltage across the dc source and within the impedance network, remain the shoot-through feature used to boost up the dc-link voltage without adding bulky filter at input side. This paper introduces a ...... a class of transformer based asymmetrical embedded Z-source inverters which keep the smooth input current and voltage while achieving enhanced voltage boost capability. The presented inverters are verified by laboratory prototypes experimentally....
Transformer-based design techniques for oscillators and frequency dividers
Luong, Howard Cam
2016-01-01
This book provides in-depth coverage of transformer-based design techniques that enable CMOS oscillators and frequency dividers to achieve state-of-the-art performance. Design, optimization, and measured performance of oscillators and frequency dividers for different applications are discussed in detail, focusing on not only ultra-low supply voltage but also ultra-wide frequency tuning range and locking range. This book will be an invaluable reference for anyone working or interested in CMOS radio-frequency or mm-Wave integrated circuits and systems.
Multi-band Image Registration Method Based on Fourier Transform
Institute of Scientific and Technical Information of China (English)
庹红娅; 刘允才
2004-01-01
This paper presented a registration method based on Fourier transform for multi-band images which is involved in translation and small rotation. Although different band images differ a lot in the intensity and features,they contain certain common information which we can exploit. A model was given that the multi-band images have linear correlations under the least-square sense. It is proved that the coefficients have no effect on the registration progress if two images have linear correlations. Finally, the steps of the registration method were proposed. The experiments show that the model is reasonable and the results are satisfying.
Research on ghost imaging method based on wavelet transform
Li, Mengying; He, Ruiqing; Chen, Qian; Gu, Guohua; Zhang, Wenwen
2017-09-01
We present an algorithm of extracting the wavelet coefficients of object based on ghost imaging (GI) system. Through modification of the projected random patterns by using a series of templates, wavelet transform GI (WTGI) can directly measure the high frequency components of wavelet coefficients without needing the original image. In this study, we theoretically and experimentally perform the high frequency components of wavelet coefficients detection with an arrow and a letter A based on GI and WTGI. Comparing with the traditional method, the use of the algorithm proposed in this paper can significantly improve the quality of the image of wavelet coefficients in both cases. The special advantages of GI will make the wavelet coefficient detection based on WTGI very valuable in real applications.
Wavelet packet transform-based robust video watermarking technique
Indian Academy of Sciences (India)
Gaurav Bhatnagar; Balasubrmanian Raman
2012-06-01
In this paper, a wavelet packet transform (WPT)-based robust video watermarking algorithm is proposed. A visible meaningful binary image is used as the watermark. First, sequent frames are extracted from the video clip. Then, WPT is applied on each frame and from each orientation one sub-band is selected based on block mean intensity value called robust sub-band. Watermark is embedded in the robust sub-bands based on the relationship between wavelet packet coefﬁcient and its 8-neighbour $(D_8)$ coefﬁcients considering the robustness and invisibility. Experimental results and comparison with existing algorithms show the robustness and the better performance of the proposed algorithm.
TP-model transformation-based-control design frameworks
Baranyi, Péter
2016-01-01
This book covers new aspects and frameworks of control, design, and optimization based on the TP model transformation and its various extensions. The author outlines the three main steps of polytopic and LMI based control design: 1) development of the qLPV state-space model, 2) generation of the polytopic model; and 3) application of LMI to derive controller and observer. He goes on to describe why literature has extensively studied LMI design, but has not focused much on the second step, in part because the generation and manipulation of the polytopic form was not tractable in many cases. The author then shows how the TP model transformation facilitates this second step and hence reveals new directions, leading to powerful design procedures and the formulation of new questions. The chapters of this book, and the complex dynamical control tasks which they cover, are organized so as to present and analyze the beneficial aspect of the family of approaches (control, design, and optimization). Additionally, the b...
Directory of Open Access Journals (Sweden)
M. Rasoulpoor
2013-09-01
Full Text Available This paper presents a new approach for power transformer differential protection. The Wavelet Transform is applied to discriminate between inrush currents and internal fault currents in power transformers. Discrete wavelet transform decomposes the current signal into sub-bands that give more information about the properties of the signals in different frequency bands. Also, this transform is used to investigate the energy distribution of the signal on the different time and frequency scales. Recognition method is based on the correlation factors between energy percentage vectors of the Wavelet coefficients. Discrete Wavelet transform is used for decomposing the current signals to different frequency coefficients. After that, by constituting the energy percentage vectors of wavelet transform coefficients and calculating the correlation factors between these vectors, it is possible to form a recognition criterion to distinguish between inrush and internal fault current in the proposed method. The proposed algorithm is tested for several conditions by simulated inrush and internal fault currents. Simulation of current signals is performed using electromagnetic transient program PSCAD/EMTDC software that is a powerful program for the investigation of transient signals. Simulation results show that the proposed scheme accurately identifies inrush and fault currents in the distance of the power transformer protection in less than quarter of power frequency cycle. Also, beside the sensitivity and high reliability, the proposed method has low computation content and unlike the common methods does not require to determine the threshold for each new power system.
A Program Transformation for Continuation Call-Based Tabled Execution
de Guzman, Pablo Chico; Hermenegildo, Manuel V
2009-01-01
The advantages of tabled evaluation regarding program termination and reduction of complexity are well known --as are the significant implementation, portability, and maintenance efforts that some proposals (especially those based on suspension) require. This implementation effort is reduced by program transformation-based continuation call techniques, at some efficiency cost. However, the traditional formulation of this proposal by Ramesh and Cheng limits the interleaving of tabled and non-tabled predicates and thus cannot be used as-is for arbitrary programs. In this paper we present a complete translation for the continuation call technique which, using the runtime support needed for the traditional proposal, solves these problems and makes it possible to execute arbitrary tabled programs. We present performance results which show that CCall offers a useful tradeoff that can be competitive with state-of-the-art implementations.
A new phase comparison pilot protection based on wavelet transform
Institute of Scientific and Technical Information of China (English)
YANG Ying; TAI Neng-ling; YU Wei-yong
2006-01-01
Current phase comparison based pilot protection had been generally utilized as primary protection of the transmission lines in China from the 1950's to the 1980's. Conventional phase comparison pilot protection has a long phase comparison time, which results in a longer fault-clearing time. This paper proposes a new current phase comparison. pilot protection scheme that is based on non-power frequency fault current component.The phase of the fourth harmonic current of each end of the protected line has been abstracted by utilizing complex wavelet transformation and then compared in order to determine whether the inner fault occurs or not. This way can greatly decrease fault-clearing time and improve performances of this pilot protection when fault occurs under the heavy-load current and asymmetrical operation conditions. Many EMTP simulations have verified theproposed scheme's correctness and effectiveness.
SPARQL Query Re-writing Using Partonomy Based Transformation Rules
Jain, Prateek; Yeh, Peter Z.; Verma, Kunal; Henson, Cory A.; Sheth, Amit P.
Often the information present in a spatial knowledge base is represented at a different level of granularity and abstraction than the query constraints. For querying ontology's containing spatial information, the precise relationships between spatial entities has to be specified in the basic graph pattern of SPARQL query which can result in long and complex queries. We present a novel approach to help users intuitively write SPARQL queries to query spatial data, rather than relying on knowledge of the ontology structure. Our framework re-writes queries, using transformation rules to exploit part-whole relations between geographical entities to address the mismatches between query constraints and knowledge base. Our experiments were performed on completely third party datasets and queries. Evaluations were performed on Geonames dataset using questions from National Geographic Bee serialized into SPARQL and British Administrative Geography Ontology using questions from a popular trivia website. These experiments demonstrate high precision in retrieval of results and ease in writing queries.
Catalytic Transformation of Ethylbenzene over Y-Zeolite-based Catalysts
Al-Khattaf, Sulaiman
2008-11-19
Catalytic transformation of ethylbenzene (EB) has been investigated over ultrastable Y (USY)-zeolite-based catalysts in a novel riser simulator at different operating conditions. The effect of reaction conditions on EB conversion is reported. The USY catalyst (FCC-Y) was modified by steaming to form a significantly lower acidity catalyst (FCC-SY). The current study shows that the FCC-SY catalyst favors EB disproportionation more than cracking. A comparison has been made between the results of EB conversion over the lowly acidic catalyst (FCC-SY) and the highly acidic catalyst (FCC-Y) under identical conditions. It was observed that increase in catalyst acidity favored cracking of EB at the expense of disproportionation. Kinetic parameters for EB disappearance during disproportionation reaction over the FCC-SY catalyst were calculated using the catalyst activity decay function based on time on stream (TOS). © 2008 American Chemical Society.
Study on Singularity of Chaotic Signal Based on Wavelet Transform
Institute of Scientific and Technical Information of China (English)
YOU Rong-yi
2006-01-01
Based on the variations of wavelet transform modulus maxima at multi-scales,the singularity of chaotic signals are studied,and the singularity of these signals are measured by the Lipschitz exponent.In the meantime,a nonlinear method is proposed based on the higher order statistics,on the other aspect,which characterizes the higher order singular spectrum (HOSS) of chaotic signals.All computations are done with Lorenz attractor,Rossler attractor and EEG (electroencephalogram) time series and the comparisions among these results are made.The experimental results show that the Lipschitz exponents and the higher order singular spectra of these signals are significantly different from each other,which indicates these methods are effective for studing the singularity of chaotic signals.
SVD-based digital image watermarking using complex wavelet transform
Indian Academy of Sciences (India)
A Mansouri; A Mahmoudi Aznaveh; F Torkamani Azar
2009-06-01
A new robust method of non-blind image watermarking is proposed in this paper. The suggested method is performed by modiﬁcation on singular value decomposition (SVD) of images in Complex Wavelet Transform (CWT) domain while CWT provides higher capacity than the real wavelet domain. Modiﬁcation of the appropriate sub-bands leads to a watermarking scheme which favourably preserves the quality. The additional advantage of the proposed technique is its robustness against the most of common attacks. Analysis and experimental results show much improved performance of the proposed method in comparison with the pure SVD-based as well as hybrid methods (e.g. DWT-SVD as the recent best SVD-based scheme).
Research of Transformer Intelligent Evaluation and Diagnosis Method Based on DGA
Directory of Open Access Journals (Sweden)
Wang Feng
2016-01-01
Full Text Available Oil chromatography analysis is the foundation of transformer fault diagnosis, In this paper, based on knowledge base of the oil chromatographic analysis, an extended research combining the improved three ratio method, BP neural network, and case-based reasoning method for the transformer fault diagnosis was proposed, in the purpose of building a transformer Intelligent Evaluation Diagnosis model, to improve the accuracy of the transformer fault diagnosis, which is of a great significance for practice.
Controlling reuse in pattern-based model-to-model transformations
Guerra, Esther,; De Lara, Juan,; Orejas, Fernando
2010-01-01
Model-to-model transformation is a central activity in Model-Driven Engineering that consists of transforming models from a source to a target language. Pattern-based model-to-model transformation is our approach for specifying transformations in a declarative, relational and formal style. The approach relies on patterns describing allowed or forbidden relations between two models. These patterns are compiled into operational mechanisms to perform forward and backward transformations. Inspire...
R-peaks detection based on stationary wavelet transform.
Merah, M; Abdelmalik, T A; Larbi, B H
2015-10-01
Automatic detection of the QRS complexes/R-peaks in an electrocardiogram (ECG) signal is the most important step preceding any kind of ECG processing and analysis. The performance of these systems heavily relies on the accuracy of the QRS detector. The objective of present work is to drive a new robust method based on stationary wavelet transform (SWT) for R-peaks detection. The decimation of the coefficients at each level of the transformation algorithm is omitted, more samples in the coefficient sequences are available and hence a better outlier detection can be performed. Using the information of local maxima, minima and zero crossings of the fourth SWT coefficient detail, the proposed algorithm identifies the significant points for detection and delineation of the QRS complexes, as well as detection and identification of the QRS individual waves peaks of the pre-processed ECG signal. Various experimental results show that the proposed algorithm exhibits reliable QRS detection as well as accurate ECG delineation, achieving excellent performance on different databases, on the MIT-BIH database (Se=99.84%, P=99.88%), on the QT Database (Se=99.94%, P=99.89%) and on MIT-BIH Noise Stress Test Database, (Se=95.30%, P=93.98%). Reliability and accuracy are close to the highest among the ones obtained in other studies. Experiments results being satisfactory, the SWT may represent a novel QRS detection tool, for a robust ECG signal analysis.
Visualization of Complex Networks Based on Dyadic Curvelet Transform
Directory of Open Access Journals (Sweden)
Kaoru Hirota
2006-07-01
Full Text Available A visualization method is proposed for understanding the structure of complex networks based on an extended Curvelet transform named Dyadic Curvelet Transform (DClet. The proposed visualization method comes to answer specific questions about structures of complex networks by mapping data into orthogonal localized events with a directional component via the Cartesian sampling sets of detail coefficients. It behaves in the same matter as human visual system, seeing in terms of segments and distinguishing them by scale and orientation. Compressing the network is another fact. The performance of the proposed method is evaluated by two different networks with structural properties of small world networks with N = 16 vertices, and a globally coupled network with size N = 1024 and 523 776 edges. As the most large scale real networks are not fully connected, it is tested on the telecommunication network of Iran as a real extremely complex network with 92 intercity switching vertices, 706 350 E1 traffic channels and 315 525 transmission channels. It is shown that the proposed method performs as a simulation tool for successfully design of network and establishing the necessary group sizes. It can clue the network designer in on all structural properties that network has.
Neural Network based Modeling and Simulation of Transformer Inrush Current
Directory of Open Access Journals (Sweden)
Puneet Kumar Singh
2012-05-01
Full Text Available Inrush current is a very important phenomenon which occurs during energization of transformer at no load due to temporary over fluxing. It depends on several factors like magnetization curve, resistant and inductance of primary winding, supply frequency, switching angle of circuit breaker etc. Magnetizing characteristics of core represents nonlinearity which requires improved nonlinearity solving technique to know the practical behavior of inrush current. Since several techniques still working on modeling of transformer inrush current but neural network ensures exact modeling with experimental data. Therefore, the objective of this study was to develop an Artificial Neural Network (ANN model based on data of switching angle and remanent flux for predicting peak of inrush current. Back Propagation with Levenberg-Marquardt (LM algorithm was used to train the ANN architecture and same was tested for the various data sets. This research work demonstrates that the developed ANN model exhibits good performance in prediction of inrush current’s peak with an average of percentage error of -0.00168 and for modeling of inrush current with an average of percentage error of -0.52913.
A Transformer Partial Discharge Measurement System Based on Fluorescent Fiber
Directory of Open Access Journals (Sweden)
Fan Liu
2012-05-01
Full Text Available Based on the physical phenomena of optical effects produced by the partial discharge (PD and on the characteristics of fluorescent fiber sensing of weak fluorescent signals, a PD measurement system using a fluorescent fiber sensor was designed. The main parameters of the sensing system were calculated, an experimental testing platform for PD simulation in the lab was established, and PD signals were then detected through ultra-high frequency (UHF and optical methods under a needle-plate discharge model. PD optical pulses in transformer oil contained signal-peak and multi-peak pulse waveforms. Compared with UHF detection results, the number of PD pulses and the elapsed PD pulse phase time revealed a good corresponding relationship. However, PD signal amplitudes presented the opposite, thus indicating that PD UHF signals reflected pulse amplitude value, whereas PD optical signals reflected pulse energy magnitude. The n-u-φ three-dimensional distributions indicated that most of the PD signals concentrated in the nearby industrial frequency voltage peak value. Overall, the proposed fluorescent fiber sensing system design can be used successfully in transformer PD signal detection.
Distance Transform Based Enhancement for Linear Interpolated Images
Institute of Scientific and Technical Information of China (English)
唐莉萍; 曾培峰
2003-01-01
An approach of distance map based image enhancement (DMIE) is proposed. It is applied to conventional interpolations to get sharp images. Edge detection is performed after images are interpolated by linear interpolations. To meet the two conditions set for DMIE, i. e., no abrupt changes and no overboosting, different boosting rate should be used in adjusting pixel intensities. When the boosting rate is determined by using the distance from enhanced pixels to nearest edges, edge-oriented image enhancement is obtained. By using Erosion technique, the range for pixel intensity adjustment is set. Over-enhancement is avoided by limiting the pixel intensities in enhancement within the range.A unified linear-time algorithm for distance transform is adopted to deal with the calculation of Euclidean distance of the images. Its computation complexity is O (N2 ). After the preparation, i. e.,distance transforming and erosion, the images get more and more sharpened while no over-boosting occurs by repeating the enhancement procedure. The simplicity of the enhancement operation makes DMIE suitable for enhancement rate adjusting.
Labunets, Valeri G.; Labunets-Rundblad, Ekaterina V.; Astola, Jaakko T.
2001-12-01
Fast algorithms for a wide class of non-separable n-dimensional (nD) discrete unitary K-transforms (DKT) are introduced. They need less 1D DKTs than in the case of the classical radix-2 FFT-type approach. The method utilizes a decomposition of the nD K-transform into the product of a new nD discrete Radon transform and of a set of parallel/independ 1D K-transforms. If the nD K-transform has a separable kernel (e.g., the case of the discrete Fourier transform) our approach leads to decrease of multiplicative complexity by the factor of n comparing to the classical row/column separable approach. It is well known that an n-th order Volterra filter of one dimensional signal can be evaluated by an appropriate nD linear convolution. This work describes new superfast algorithm for Volterra filtering. New approach is based on the superfast discrete Radon and Nussbaumer polynomial transforms.
Institute of Scientific and Technical Information of China (English)
Wang Chuandan; Zhang Zhongpei; Li Shaoqian
2007-01-01
The method of FRactional Fourier Transform (FRFT) is introduced to Transform Domain Communication System (TDCS) for signal transforming in the paper after theoretical analysis. The method yields optimal Basis Function (BF) by FRFT with optimal transform angle. The TDCS using the proposed method has wider usable spectrum, stronger robustness and better ability of anti non-stationary jamming than using usual methods, such as Fourier Transform (FT), Auto Regressive (AR), Wavelet Transform (WT), etc. The main simulation results are as follows. First, the Bit Error Rate (BER) Pb is close to theoretical bound of no jamming no matter in single tone or in linear chirp interference. Second, the interference-to-signal ratio J/E is at least 12dB more than that of Direct Spread Spectrum System (DSSS) under the same BER if the spectrum hopping-to-signal ratio is 1:20 in chirp plus hopping interfering. Third, the Eb/No (when estimation difference is 90% between transmitter and receiver) is about 3.5dB or about 0.5dB (when estimation difference is 10% between transmitter and receiver) more than that of theoretical result when no estimation difference under Pb = 10-2.
Effects of increased microwave heating power in the stellarator TJ-K
Energy Technology Data Exchange (ETDEWEB)
Munoz, Alejandro; Koehn, Alf; Ali, Ahmed; Ramisch, Mirko [Institute of Interfacial Process Engineering and Plasma Technology, University of Stuttgart, Stuttgart (Germany)
2015-05-01
One of the microwave heating systems at the stellarator TJ-K has been recently upgraded: a third klystron has been installed, increasing the heating power from 4 kW to 6 kW operating at 14 GHz. A phased-array antenna is used which allows to vary the injection angle by sweeping the microwave frequency in order control the coupling mechanism of the microwave to the plasma. With the two klystrons already installed, ionization degrees of α ≅ 1 have been reached. We expect that an increased heating power, by means of the third klystron put into operation, leads to an increase in the electron temperature T{sub e} only, rather than in electron density n{sub e}, and thus a decrease in the collision frequency ν{sub ei} ∝ n{sub e}T{sub e}{sup -3/2} which has an impact on heating flow damping and neoclassical properties. Parameter scans have been performed in order to characterize the new heating scenario. A radial movable Langmuir probe has been used to obtain radial profiles of the electron density and temperature. An arrangement of bolometers and an optical diode have been used to obtain the power losses by radiation. A particle and power balance model is used to obtain estimated densities and temperatures in order to compare with the experimental results.
Performance Evaluation of Image Fusion Based on Discrete Cosine Transform
Directory of Open Access Journals (Sweden)
Ramkrishna Patil
2013-05-01
Full Text Available Discrete cosine transform (DCT is used for fusion of two different images and for image compression. Image fusion deals with creating an image by combining portions from other images to obtain an image in which all of the objects are in focus. Two multi focus images are used for image fusion. Different fusion algorithms are used and their performance is evaluated using evaluation metrics such as PSNR, SSIM, Spatial Frequency, Quality Index, Structural Content, Mean Absolute Error. Fusion performance is not good while using the algorithms with block size less than 64x64 and also the block size of 512x512. Contrast, amplitude and energy based image fusion algorithms performed well. The fused images are comparable with the reference image. Only the image size is considered but blurring percentage is not considered. These algorithms are very simple and might be suitable for real time applications
Fixed Point Transformations Based Iterative Control of a Polymerization Reaction
Tar, József K.; Rudas, Imre J.
As a paradigm of strongly coupled non-linear multi-variable dynamic systems the mathematical model of the free-radical polymerization of methyl-metachrylate with azobis (isobutyro-nitrile) as an initiator and toluene as a solvent taking place in a jacketed Continuous Stirred Tank Reactor (CSTR) is considered. In the adaptive control of this system only a single input variable is used as the control signal (the process input, i.e. dimensionless volumetric flow rate of the initiator), and a single output variable is observed (the process output, i.e. the number-average molecular weight of the polymer). Simulation examples illustrate that on the basis of a very rough and primitive model consisting of two scalar variables various fixed-point transformations based convergent iterations result in a novel, sophisticated adaptive control.
Remote Sensing Image Resolution Enlargement Algorithm Based on Wavelet Transformation
Directory of Open Access Journals (Sweden)
Samiul Azam
2014-05-01
Full Text Available In this paper, we present a new image resolution enhancement algorithm based on cycle spinning and stationary wavelet subband padding. The proposed technique or algorithm uses stationary wavelet transformation (SWT to decompose the low resolution (LR image into frequency subbands. All these frequency subbands are interpolated using either bicubic or lanczos interpolation, and these interpolated subbands are put into inverse SWT process for generating intermediate high resolution (HR image. Finally, cycle spinning (CS is applied on this intermediate high resolution image for reducing blocking artifacts, followed by, traditional Laplacian sharpening filter is used to make the generated high resolution image sharper. This new technique has been tested on several satellite images. Experimental result shows that the proposed technique outperforms the conventional and the state-of-the-art techniques in terms of peak signal to noise ratio, root mean square error, entropy, as well as, visual perspective.
Computing Dialogue Acts from Features with Transformation-Based Learning
Samuel, K B; Vijay-Shanker, K; Samuel, Ken; Carberry, Sandra
1998-01-01
To interpret natural language at the discourse level, it is very useful to accurately recognize dialogue acts, such as SUGGEST, in identifying speaker intentions. Our research explores the utility of a machine learning method called Transformation-Based Learning (TBL) in computing dialogue acts, because TBL has a number of advantages over alternative approaches for this application. We have identified some extensions to TBL that are necessary in order to address the limitations of the original algorithm and the particular demands of discourse processing. We use a Monte Carlo strategy to increase the applicability of the TBL method, and we select features of utterances that can be used as input to improve the performance of TBL. Our system is currently being tested on the VerbMobil corpora of spoken dialogues, producing promising preliminary results.
Machine vision inspection of rice seed based on Hough transform
Institute of Scientific and Technical Information of China (English)
成芳; 应义斌
2004-01-01
A machine vision system was developed to inspect the quality of rice seeds. Five varieties of Jinyou402, Shanyou10, Zhongyou207, Jiayou and IIyou were evaluated. The images of both sides of rice seed with black background and white background were acquired with the image processing system for identifying external features of rice seeds. Five image sets consisting of 600 original images each were obtained. Then a digital image processing algorithm based on Hough transform was developed to inspect the rice seeds with incompletely closed glumes. The algorithm was implemented with all image sets using a Matlab 6.5 procedure. The results showed that the algorithm achieved an average accuracy of 96% for normal seeds, 92% for seeds with fine fissure and 87% for seeds with incompletely closed glumes. The algorithm was proved to be applicable to different seed varieties and insensitive to the color of the background.
Grating geophone signal processing based on wavelet transform
Li, Shuqing; Zhang, Huan; Tao, Zhifei
2008-12-01
Grating digital geophone is designed based on grating measurement technique benefiting averaging-error effect and wide dynamic range to improve weak signal detected precision. This paper introduced the principle of grating digital geophone and its post signal processing system. The signal acquisition circuit use Atmega 32 chip as core part and display the waveform on the Labwindows through the RS232 data link. Wavelet transform is adopted this paper to filter the grating digital geophone' output signal since the signal is unstable. This data processing method is compared with the FIR filter that widespread use in current domestic. The result indicates that the wavelet algorithm has more advantages and the SNR of seismic signal improve obviously.
Scale Invariant Feature Transform Based Fingerprint Corepoint Detection
Directory of Open Access Journals (Sweden)
Madasu Hanmandlu
2013-07-01
Full Text Available The detection of singular points (core and delta accurately and reliably is very important for classification and matching of fingerprints. This paper presents a new approach for core point detection based on scale invariant feature transform (SIFT. Firstly, SIFT points are extracted ,then reliability and ridge frequency criteria are applied to reduce the candidate points required to make a decision on the core point. Finally a suitable mask is applied to detect an accurate core point. Experiments on FVC2002 and FVC2004 databases show that our approach locates a unique reference point with high accuracy. Results of our approach are compared with those of the existing methods in terms of accuracy of core point detection.Defence Science Journal, 2013, 63(4, pp.402-407, DOI:http://dx.doi.org/10.14429/dsj.63.2708
Machine vision inspection of rice seed based on Hough transform
Institute of Scientific and Technical Information of China (English)
成芳; 应义斌
2004-01-01
A machine vision system was developed to inspect the quality of rice seeds. Five varieties of Jinyou402,Shanyou 10, Zhongyou207, Jiayou and Ilyou were evaluated. The images of both sides of rice seed with black background and white background were acquired with the image processing system for identifying external features of rice seeds. Five image sets consisting of 600 original images each were obtained. Then a digital image processing algorithm based on Hough transform was developed to inspect the rice seeds with incompletely closed glumes. The algorithm was implemented with all image sets using a Matlab 6.5 procedure. The results showed that the algorithm achieved an average accuracy of 96% for normal seeds, 92% for seeds with fine fissure and 87% for seeds with incompletely closed glumes. The algorithm was proved to be applicable to different seed varieties and insensitive to the color of the background.
An Asymmetric Image Encryption Based on Phase Truncated Hybrid Transform
Khurana, Mehak; Singh, Hukum
2017-09-01
To enhance the security of the system and to protect it from the attacker, this paper proposes a new asymmetric cryptosystem based on hybrid approach of Phase Truncated Fourier and Discrete Cosine Transform (PTFDCT) which adds non linearity by including cube and cube root operation in the encryption and decryption path respectively. In this cryptosystem random phase masks are used as encryption keys and phase masks generated after the cube operation in encryption process are reserved as decryption keys and cube root operation is required to decrypt image in decryption process. The cube and cube root operation introduced in the encryption and decryption path makes system resistant against standard attacks. The robustness of the proposed cryptosystem has been analysed and verified on the basis of various parameters by simulating on MATLAB 7.9.0 (R2008a). The experimental results are provided to highlight the effectiveness and suitability of the proposed cryptosystem and prove the system is secure.
Research on Transformer Fault Based on Probabilistic Neural Network
Directory of Open Access Journals (Sweden)
Li Yingshun
2015-01-01
Full Text Available With the development of computer science and technology, and increasingly intelligent industrial production, the application of big data in industry also advances rapidly, and the development of artificial intelligence in the aspect of fault diagnosis is particularly prominent. On the basis of MATLAB platform, this paper constructs a fault diagnosis expert system of artificial intelligence machine based on the probabilistic neural network, and it also carries out a simulation of production process by the use of bionic algorithm. This paper makes a diagnosis of transformer fault by the use of an expert system developed by this paper, and verifies that the probabilistic neural network has a good convergence, fault-tolerant ability and big data handling capability in the fault diagnosis. It is suitable for industrial production, which can provide a reliable mathematical model for the construction of fault diagnosis expert system in the industrial production.
Psychoacoustic Music Analysis Based on the Discrete Wavelet Packet Transform
Directory of Open Access Journals (Sweden)
Xing He
2008-01-01
Full Text Available Psychoacoustical computational models are necessary for the perceptual processing of acoustic signals and have contributed significantly in the development of highly efficient audio analysis and coding. In this paper, we present an approach for the psychoacoustic analysis of musical signals based on the discrete wavelet packet transform. The proposed method mimics the multiresolution properties of the human ear closer than other techniques and it includes simultaneous and temporal auditory masking. Experimental results show that this method provides better masking capabilities and it reduces the signal-to-masking ratio substantially more than other approaches, without introducing audible distortion. This model can lead to greater audio compression by permitting further bit rate reduction and more secure watermarking by providing greater signal space for information hiding.
Adaptive Dual-Threshold Edge Detection Based on Wavelet Transform
Institute of Scientific and Technical Information of China (English)
侯舒娟; 梅文博; 张志明
2003-01-01
In order to solve the problems of local-maximum modulus extraction and threshold selection in the edge detection of finite-resolution digital images, a new wavelet transform based adaptive dual-threshold edge detection algorithm is proposed. The local-maximum modulus is extracted by linear interpolation in wavelet domain. With the analysis on histogram, the image is filtered with an adaptive dual-threshold method, which effectively detects the contours of small structures as well as the boundaries of large objects. A wavelet domain's propagation function is used to further select weak edges. Experimental results have shown the self-adaptivity of the threshold to images having the same kind of histogram, and the efficiency even in noise-tampered images.
A Hough Transform based Technique for Text Segmentation
Saha, Satadal; Nasipuri, Mita; Basu, Dipak Kr
2010-01-01
Text segmentation is an inherent part of an OCR system irrespective of the domain of application of it. The OCR system contains a segmentation module where the text lines, words and ultimately the characters must be segmented properly for its successful recognition. The present work implements a Hough transform based technique for line and word segmentation from digitized images. The proposed technique is applied not only on the document image dataset but also on dataset for business card reader system and license plate recognition system. For standardization of the performance of the system the technique is also applied on public domain dataset published in the website by CMATER, Jadavpur University. The document images consist of multi-script printed and hand written text lines with variety in script and line spacing in single document image. The technique performs quite satisfactorily when applied on mobile camera captured business card images with low resolution. The usefulness of the technique is verifie...
Adaptive image fusion based on nonsubsampled contourlet transform
Zhang, Xiongmei; Li, Junshan; Yi, Zhaoxiang; Yang, Wei
2007-11-01
Multiresolution-based image fusion has been the focus of considerable research attention in recent years with a number of algorithms proposed. In most of the algorithms, however, the parameter configuration is usually based on experience. This paper proposes an adaptive image fusion algorithm based on the nonsubsampled contourlet transform (NSCT), which realizes automatic parameter adjustment and gets rid of the adverse effect caused by artificial factors. The algorithm incorporates the quality metric of structural similarity (SSIM) into the NSCT fusion framework. The SSIM value is calculated to assess the fused image quality, and then it is fed back to the fusion algorithm to achieve a better fusion by directing parameters (level of decomposition and flag of decomposition direction) adjustment. Based on the cross entropy, the local cross entropy (LCE) is constructed and used to determine an optimal choice of information source for the fused coefficients at each scale and direction. Experimental results show that the proposed method achieves the best fusion compared to three other methods judged on both the objective metrics and visual inspection and exhibits robust against varying noises.
Wavelet Packet Transform Based Driver Distraction Level Classification Using EEG
Directory of Open Access Journals (Sweden)
Mousa Kadhim Wali
2013-01-01
Full Text Available We classify the driver distraction level (neutral, low, medium, and high based on different wavelets and classifiers using wireless electroencephalogram (EEG signals. 50 subjects were used for data collection using 14 electrodes. We considered for this research 4 distraction stimuli such as Global Position Systems (GPS, music player, short message service (SMS, and mental tasks. Deriving the amplitude spectrum of three different frequency bands theta, alpha, and beta of EEG signals was based on fusion of discrete wavelet packet transform (DWPT and FFT. Comparing the results of three different classifiers (subtractive fuzzy clustering probabilistic neural network, -nearest neighbor was based on spectral centroid, and power spectral features extracted by different wavelets (db4, db8, sym8, and coif5. The results of this study indicate that the best average accuracy achieved by subtractive fuzzy inference system classifier is 79.21% based on power spectral density feature extracted by sym8 wavelet which gave a good class discrimination under ANOVA test.
Institute of Scientific and Technical Information of China (English)
ZENG Qing-hu; QIU Jing; LIU Guan-jun
2007-01-01
Noise is the biggest obstacle that makes the incipient fault diagnosis results of roller bearings uncorrected; a new method for diagnosing incipient fault of roller bearings based on the Wavelet Transform Correlation Filter and Hilbert Transform was proposed. First, the weak fault information features are picked up from the roller bearings fault vibration signals by use of a de-noising characteristic of the Wavelet Transform Correlation Filter as the preprocessing of the Hilbert Envelope Analysis. Then, in order to get fault features frequency, de-noised wavelet coefficients of high scales which represent high frequency signal were analyzed by Hilbert Envelope Spectrum Analysis. The simulation signals and diagnosing examples analysis results reveal that the proposed method is more effective than the method of direct wavelet coefficients-Hilbert Transform in de-noising and clarifying roller bearing incipient fault.
Undersampled Hyperspectral Image Reconstruction Based on Surfacelet Transform
Directory of Open Access Journals (Sweden)
Lei Liu
2015-01-01
Full Text Available Hyperspectral imaging is a crucial technique for military and environmental monitoring. However, limited equipment hardware resources severely affect the transmission and storage of a huge amount of data for hyperspectral images. This limitation has the potentials to be solved by compressive sensing (CS, which allows reconstructing images from undersampled measurements with low error. Sparsity and incoherence are two essential requirements for CS. In this paper, we introduce surfacelet, a directional multiresolution transform for 3D data, to sparsify the hyperspectral images. Besides, a Gram-Schmidt orthogonalization is used in CS random encoding matrix, two-dimensional and three-dimensional orthogonal CS random encoding matrixes and a patch-based CS encoding scheme are designed. The proposed surfacelet-based hyperspectral images reconstruction problem is solved by a fast iterative shrinkage-thresholding algorithm. Experiments demonstrate that reconstruction of spectral lines and spatial images is significantly improved using the proposed method than using conventional three-dimensional wavelets, and growing randomness of encoding matrix can further improve the quality of hyperspectral data. Patch-based CS encoding strategy can be used to deal with large data because data in different patches can be independently sampled.
Recognizing articulated objects using a region-based invariant transform.
Weiss, Isaac; Ray, Manjit
2005-10-01
In this paper, we present a new method for representing and recognizing objects, based on invariants of the object's regions. We apply the method to articulated objects in low-resolution, noisy range images. Articulated objects such as a back-hoe can have many degrees of freedom, in addition to the unknown variables of viewpoint. Recognizing such an object in an image can involve a search in a high-dimensional space that involves all these unknown variables. Here, we use invariance to reduce this search space to a manageable size. The low resolution of our range images makes it hard to use common features such as edges to find invariants. We have thus developed a new "featureless" method that does not depend on feature detection. Instead of local features, we deal with whole regions of the object. We define a "transform" that converts the image into an invariant representation on a grid, based on invariant descriptors of entire regions centered around the grid points. We use these region-based invariants for indexing and recognition. While the focus here is on articulation, the method can be easily applied to other problems such as the occlusion of fixed objects.
Multifocus watermarking approach based on discrete cosine transform.
Waheed, Safa Riyadh; Alkawaz, Mohammed Hazim; Rehman, Amjad; Almazyad, Abdulaziz S; Saba, Tanzila
2016-05-01
Image fusion process consolidates data and information from various images of same sight into a solitary image. Each of the source images might speak to a fractional perspective of the scene, and contains both "pertinent" and "immaterial" information. In this study, a new image fusion method is proposed utilizing the Discrete Cosine Transform (DCT) to join the source image into a solitary minimized image containing more exact depiction of the sight than any of the individual source images. In addition, the fused image comes out with most ideal quality image without bending appearance or loss of data. DCT algorithm is considered efficient in image fusion. The proposed scheme is performed in five steps: (1) RGB colour image (input image) is split into three channels R, G, and B for source images. (2) DCT algorithm is applied to each channel (R, G, and B). (3) The variance values are computed for the corresponding 8 × 8 blocks of each channel. (4) Each block of R of source images is compared with each other based on the variance value and then the block with maximum variance value is selected to be the block in the new image. This process is repeated for all channels of source images. (5) Inverse discrete cosine transform is applied on each fused channel to convert coefficient values to pixel values, and then combined all the channels to generate the fused image. The proposed technique can potentially solve the problem of unwanted side effects such as blurring or blocking artifacts by reducing the quality of the subsequent image in image fusion process. The proposed approach is evaluated using three measurement units: the average of Q(abf), standard deviation, and peak Signal Noise Rate. The experimental results of this proposed technique have shown good results as compared with older techniques.
F-Alloy: An Alloy Based Model Transformation Language
Gammaitoni, Loïc; Kelsen, Pierre
2015-01-01
Model transformations are one of the core artifacts of a model-driven engineering approach. The relational logic language Alloy has been used in the past to verify properties of model transformations. In this paper we introduce the concept of functional Alloy modules. In essence a functional Alloy module can be viewed as an Alloy module representing a model transformation. We describe a sublanguage of Alloy called F-Alloy that allows the specification of functional Alloy modules. Module...
Extraction of MHD Signal Based on Wavelet Transform
Institute of Scientific and Technical Information of China (English)
赵晴初; 赵彤; 李旻; 黄胜华; 徐佩霞
2002-01-01
Mirnov signals mixed with interferences are a kind of non-stationary signal. It can not obtain satisfactory effects to extract MHD signals from mirnov signals by Fourier Transform. This paper suggests that the wavelet transform can be used to treat mirnov signals. Theoretical analysis and experimental result have indicated that using the time-frequency analysis characteristics of the wavelet transform to filter mirnov signals can remove effectively interferences and extract useful MHD signals.
License Plate Recognition Based on Transform Coding and Neural Network
Institute of Scientific and Technical Information of China (English)
李小平; 胡海生; 宋瀚涛; 朱建学; 丁俨
2003-01-01
A method of vehicle license plate recognition utilizing Karhunen-Loeve(K-L) transform is provided. The transform is used to extract features from a mass of image templates, to describe high-dimensional images with low-dimensional ones, and moreover, to implement data compression and play down complexity of the neural network. With the character to reduce eigenspace dimensionality of K-L transform and the ability to map data of BP network, the method does effectively in recognizing license plates.
A New Class of Analysis-Based Fast Transforms
2007-08-06
Standards), Washington, DC, 1964. [2] Arfken , George B. and Hans J. Weber, Mathematical Methods for Physicists, 6th ed., Elsevier Academic Press, New York...procedure as the “butterfly” algorithm. Another class of transforms common in mathematical physics and classical mathematics are integral transforms...to as the kernel of the integral transform. One may desire to evaluate the function Kf at n values y1, y2, . . . , yn. Standard methods for the
Comparison on Integer Wavelet Transforms in Spherical Wavelet Based Image Based Relighting
Institute of Scientific and Technical Information of China (English)
WANGZe; LEEYin; LEUNGChising; WONGTientsin; ZHUYisheng
2003-01-01
To provide a good quality rendering in the Image based relighting (IBL) system, tremendous reference images under various illumination conditions are needed. Therefore data compression is essential to enable interactive action. And the rendering speed is another crucial consideration for real applications. Based on Spherical wavelet transform (SWT), this paper presents a quick representation method with Integer wavelet transform (IWT) for the IBL system. It focuses on comparison on different IWTs with the Embedded zerotree wavelet (EZW) used in the IBL system. The whole compression procedure contains two major compression steps. Firstly, SWT is applied to consider the correlation among different reference images. Secondly, the SW transformed images are compressed with IWT based image compression approach. Two IWTs are used and good results are showed in the simulations.
Moment-Based Method to Estimate Image Affine Transform
Institute of Scientific and Technical Information of China (English)
FENG Guo-rui; JIANG Ling-ge
2005-01-01
The estimation of affine transform is a crucial problem in the image recognition field. This paper resorted to some invariant properties under translation, rotation and scaling, and proposed a simple method to estimate the affine transform kernel of the two-dimensional gray image. Maps, applying to the original, produce some correlative points that can accurately reflect the affine transform feature of the image. Furthermore, unknown variables existing in the kernel of the transform are calculated. The whole scheme only refers to one-order moment,therefore, it has very good stability.
Implementation of Time-Scale Transformation Based on Continuous Wavelet Theory
Institute of Scientific and Technical Information of China (English)
无
2000-01-01
The basic objective of time-scale transformation is to compress or expand the signal in time field while keeping the same spectral properties.This paper presents two methods to derive time-scale transformation formula based on continuous wavelet transform.For an arbitrary given square-integrable function f(t),g(t) = f(t/λ) is derived by continuous wavelet transform and its inverse transform.The result shows that time-scale transformation may be obtained through the modification of the time-scale of wavelet function filter using equivalent substitution. The paper demonstrates the result by theoretic derivations and experimental simulation.
Background Subtraction Based on Three-Dimensional Discrete Wavelet Transform.
Han, Guang; Wang, Jinkuan; Cai, Xi
2016-03-30
Background subtraction without a separate training phase has become a critical task, because a sufficiently long and clean training sequence is usually unavailable, and people generally thirst for immediate detection results from the first frame of a video. Without a training phase, we propose a background subtraction method based on three-dimensional (3D) discrete wavelet transform (DWT). Static backgrounds with few variations along the time axis are characterized by intensity temporal consistency in the 3D space-time domain and, hence, correspond to low-frequency components in the 3D frequency domain. Enlightened by this, we eliminate low-frequency components that correspond to static backgrounds using the 3D DWT in order to extract moving objects. Owing to the multiscale analysis property of the 3D DWT, the elimination of low-frequency components in sub-bands of the 3D DWT is equivalent to performing a pyramidal 3D filter. This 3D filter brings advantages to our method in reserving the inner parts of detected objects and reducing the ringing around object boundaries. Moreover, we make use of wavelet shrinkage to remove disturbance of intensity temporal consistency and introduce an adaptive threshold based on the entropy of the histogram to obtain optimal detection results. Experimental results show that our method works effectively in situations lacking training opportunities and outperforms several popular techniques.
SAR-based vibrometry using the fractional Fourier transform
Campbell, Justin B.; Wang, Qi; Ade-Bello, Jelili; Caudana, Humberto; Trujillo, Nicole B.; Bhatta, Ishwor; Dunkel, Ralf; Atwood, Thomas; Doerry, Armin; Gerstle, Walter H.; Santhanam, Balu; Hayat, Majeed M.
2015-05-01
A fundamental assumption when applying Synthetic Aperture Radar (SAR) to a ground scene is that all targets are motionless. If a target is not stationary, but instead vibrating in the scene, it will introduce a non-stationary phase modulation, termed the micro-Doppler effect, into the returned SAR signals. Previously, the authors proposed a pseudosubspace method, a modification to the Discrete Fractional Fourier Transform (DFRFT), which demonstrated success for estimating the instantaneous accelerations of vibrating objects. However, this method may not yield reliable results when clutter in the SAR image is strong. Simulations and experimental results have shown that the DFRFT method can yield reliable results when the signal-to-clutter ratio (SCR) > 8 dB. Here, we provide the capability to determine a target's frequency and amplitude in a low SCR environment by presenting two methods that can perform vibration estimations when SCR < 3 dB. The first method is a variation and continuation of the subspace approach proposed previously in conjunction with the DFRFT. In the second method, we employ the dual-beam SAR collection architecture combined with the extended Kalman filter (EKF) to extract information from the returned SAR signals about the vibrating target. We also show the potential for extending this SAR-based capability to remotely detect and classify objects housed inside buildings or other cover based on knowing the location of vibrations as well as the vibration histories of the vibrating structures that house the vibrating objects.
Typical Phases of Transformative Learning: A Practice-Based Model
Nohl, Arnd-Michael
2015-01-01
Empirical models of transformative learning offer important insights into the core characteristics of this concept. Whereas previous analyses were limited to specific social groups or topical terrains, this article empirically typifies the phases of transformative learning on the basis of a comparative analysis of various social groups and topical…
Yulianto, Muhamad; Agustina, Sri Endah; Hartulistiyoso, Edy; Nelwan, Leopold Oscar; Nurlela
2017-03-01
Indonesia is one of tropical country in the world, therefore biomass product can find a lot in Indonesia. In the other side, waste of agricultural product is one of biomass resources which is can be converting to energy using Combine Heat Power for the example. In this paper, will be discussed about the temperature characterization due to influence of feeding rate and air flow rate. The contribution of this paper will show the temperature achievement of flue gas as the result of direct combustion in a stove. The research conducted using coconut shell as raw fuel material with varying feed rate and air flow rate. In this research also use the excess air to know the effect. The result show that the temperature of flue gas in direct combustion of coconut shell can reach of 520°C and temperature at combustion chamber reach 840°C. This achievement is occurring in the certain variation of experiment.
Improved Fast Fourier Transform Based Method for Code Accuracy Quantification
Energy Technology Data Exchange (ETDEWEB)
Ha, Tae Wook; Jeong, Jae Jun [Pusan National University, Busan (Korea, Republic of); Choi, Ki Yong [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)
2015-10-15
The capability of the proposed method is discussed. In this study, the limitations of the FFTBM were analyzed. The FFTBM produces quantitatively different results due to its frequency dependence. Because the problem is intensified by including a lot of high frequency components, a new method using a reduced cut-off frequency was proposed. The results of the proposed method show that the shortcomings of FFTBM are considerably relieved. Among them, the fast Fourier transform based method (FFTBM) introduced in 1990 has been widely used to evaluate a code uncertainty or accuracy. Prosek et al., (2008) identified its drawbacks, the so-called 'edge effect'. To overcome the problems, an improved FFTBM by signal mirroring (FFTBM-SM) was proposed and it has been used up to now. In spite of the improvement, the FFTBM-SM yielded different accuracy depending on the frequency components of a parameter, such as pressure, temperature and mass flow rate. Therefore, it is necessary to reduce the frequency dependence of the FFTBMs. In this study, the deficiencies of the present FFTBMs are analyzed and a new method is proposed to mitigate its frequency dependence.
Optimal image-fusion method based on nonsubsampled contourlet transform
Dou, Jianfang; Li, Jianxun
2012-10-01
The optimization of image fusion is researched. Based on the properties of nonsubsampled contourlet transform (NSCT), shift invariance, multiscale and multidirectional expansion, the fusion parameters of the multiscale decompostion scheme is optimized. In order to meet the requirement of feedback optimization, a new image fusion quality metric of image quality index normalized edge association (IQI-NEA) is built. A polynomial model is adopted to establish the relationship between the IQI_NEA metric and several decomposition levels. The optimal fusion includes four steps. First, the source images are decomposed in NSCT domain for several given levels. Second, principal component analysis is adopted to fuse the low frequency coefficients and the maximum fusion rule is utilized to fuse the high frequency coefficients to obtain the fused coefficients and the fused result is reconstructed from the obtained fused coefficients. Third, calculate the fusion quality metric IQI_NEA for the source images and fused images. Finally, the optimal fused image and optimal level are obtained through extremum properties of polynomials function. The visual and statistical results show that the proposed method has optimized the fusion performance compared to the existing fusion schemes, in terms of the visual effects and quantitative fusion evaluation indexes.
Redundant Discrete Wavelet Transform Based Super-Resolution Using Sub-Pixel Image Registration
2003-03-01
AFIT/GE/ENG/03-18 REDUNDANT DISCRETE WAVELET TRANSFORM BASED SUPER-RESOLUTION USING SUB-PIXEL IMAGE REGISTRATION THESIS Daniel L. Ward Second...position of the United States Air Force, Department of Defense, or the United States Government. AFIT/GE/ENG/03-18 REDUNDANT DISCRETE WAVELET TRANSFORM BASED...O3-18 REDUNDANT DISCRETE WAVELET TRANSFORM BASED SUPER-RESOLUTION USING SUB-PIXEL IMAGE REGISTRATION THESIS Daniel Lee Ward, B.S.E.E. Second
Compressed wideband spectrum sensing based on discrete cosine transform.
Wang, Yulin; Zhang, Gengxin
2014-01-01
Discrete cosine transform (DCT) is a special type of transform which is widely used for compression of speech and image. However, its use for spectrum sensing has not yet received widespread attention. This paper aims to alleviate the sampling requirements of wideband spectrum sensing by utilizing the compressive sampling (CS) principle and exploiting the unique sparsity structure in the DCT domain. Compared with discrete Fourier transform (DFT), wideband communication signal has much sparser representation and easier implementation in DCT domain. Simulation result shows that the proposed DCT-CSS scheme outperforms the conventional DFT-CSS scheme in terms of MSE of reconstruction signal, detection probability, and computational complexity.
Compressed Wideband Spectrum Sensing Based on Discrete Cosine Transform
Directory of Open Access Journals (Sweden)
Yulin Wang
2014-01-01
Full Text Available Discrete cosine transform (DCT is a special type of transform which is widely used for compression of speech and image. However, its use for spectrum sensing has not yet received widespread attention. This paper aims to alleviate the sampling requirements of wideband spectrum sensing by utilizing the compressive sampling (CS principle and exploiting the unique sparsity structure in the DCT domain. Compared with discrete Fourier transform (DFT, wideband communication signal has much sparser representation and easier implementation in DCT domain. Simulation result shows that the proposed DCT-CSS scheme outperforms the conventional DFT-CSS scheme in terms of MSE of reconstruction signal, detection probability, and computational complexity.
Design and performance of a pulse transformer based on Fe-based nanocrystalline core.
Yi, Liu; Xibo, Feng; Lin, Fuchang
2011-08-01
A dry-type pulse transformer based on Fe-based nanocrystalline core with a load of 0.88 nF, output voltage of more than 65 kV, and winding ratio of 46 is designed and constructed. The dynamic characteristics of Fe-based nanocrystalline core under the impulse with the pulse width of several microseconds were studied. The pulse width and incremental flux density have an important effect on the pulse permeability, so the pulse permeability is measured under a certain pulse width and incremental flux density. The minimal volume of the toroidal pulse transformer core is determined by the coupling coefficient, the capacitors of the resonant charging circuit, incremental flux density, and pulse permeability. The factors of the charging time, ratio, and energy transmission efficiency in the resonant charging circuit based on magnetic core-type pulse transformer are analyzed. Experimental results of the pulse transformer are in good agreement with the theoretical calculation. When the primary capacitor is 3.17 μF and charge voltage is 1.8 kV, a voltage across the secondary capacitor of 0.88 nF with peak value of 68.5 kV, rise time (10%-90%) of 1.80 μs is obtained.
PALMPRINT VERIFICATION USING INVARIANT MOMENTS BASED ON WAVELET TRANSFORM
Directory of Open Access Journals (Sweden)
Inass SH. Hussein
2014-01-01
Full Text Available Data security is one of the important issues among computer users. Data security can prevent fraudulent users from accessing an individual’s personal data. The biometrics recognition as one of the most important parts in the security of the data and the application of computer vision. The biometrics is the authentication method used in a wide variety of applications such as e-banking, e-commerce, e-government and many others. A biometric system is one which requires the recognition of a pattern, whereby it enables the differentiation of features from one individual to another. Biometric technologies, thus may be defined as the automated methods of identifying, or authenticating, the identity of a living person based on physiological or behavioral traits. This study emphasizes palmprint recognition, which provides a wide deployment range of authentication methods. The palmprint contains principal lines, wrinkles, fine lines, ridges and surface area; thus the palmprint of person differs from one to another. Previous researchers have difficulty extracting the features of a palm print, because of the effects of rotation, translation and scaling changes and the accuracy rate of verification performance needs to be improved. The aim of this study is to extract shape features using an invariant moments algorithm based on wavelet transform and identify the person’s verification. This model has shown a promising results without the effects of rotation, translation and scaling of objects, because it is associated with the use of a good description of shape features. This system has been tested using databases from the Indian Institute of Technology, Kanpur (IITK, by using the False Rejection Rate (FRR and False Acceptance Rate (FAR, we may calculate the accuracy rate of verification. The experiment shows a 97.99% accuracy rate of verification.
State-of-the-art piezoelectric transformer-based switch mode power supplies
DEFF Research Database (Denmark)
Ekhtiari, Marzieh; Zhang, Zhe; Andersen, Michael A. E.
2014-01-01
Inductorless switch mode power supplies based on piezoelectric transformers are used to replace conventional transformers in high power density switch mode power supplies. Even though piezoelectric-based converters exhibit a high d egree of nonlinearity, it is desirable to use piezoelectric transfo...... discusses power supplies with the trend evaluation of piezoelectric transformer-based converter topologies and control methods. The challenges of piezoelectric transformers regarding soft switching capability and nonlinearity are addressed. This paper can be used as a guideline f or choosing a proper...... topology of piezoelectric-based switch mode power supply and a control method for the required application....
A transformation approach for collaboration based requirement models
Harbouche, Ahmed; Mokhtari, Aicha
2012-01-01
Distributed software engineering is widely recognized as a complex task. Among the inherent complexities is the process of obtaining a system design from its global requirement specification. This paper deals with such transformation process and suggests an approach to derive the behavior of a given system components, in the form of distributed Finite State Machines, from the global system requirements, in the form of an augmented UML Activity Diagrams notation. The process of the suggested approach is summarized in three steps: the definition of the appropriate source Meta-Model (requirements Meta-Model), the definition of the target Design Meta-Model and the definition of the rules to govern the transformation during the derivation process. The derivation process transforms the global system requirements described as UML diagram activities (extended with collaborations) to system roles behaviors represented as UML finite state machines. The approach is implemented using Atlas Transformation Language (ATL).
A new method for classification of Brachiopods based on the radon transformation
Directory of Open Access Journals (Sweden)
Youssef Ait khouya
2011-09-01
Full Text Available Brachiopods have a lateral outline which is quite important in systematic studies. It is often assessed by a qualitative evaluation and linear measurements, which are not clear enough and precise for describing the shape of the shell and its changes In this paper we propose a new method for classification of fossils based on the radon transform from their greyscale image. We take the case of brachiopods which has Complex shapes. We use an adaptation of Radon transform called R-transform which is invariant to common geometrical transformations. Each shape is described by R3D transform. We consider the grayscale image as a set of cuts obtained from successive binarization for each gray level in image, and for each segmentation we compute the R-transform then we obtained the R3D transform. The advantages of the proposed method are robustness to noise, and invariant to common geometrical transformations scale, translation and rotation.
Lossless image compression with projection-based and adaptive reversible integer wavelet transforms.
Deever, Aaron T; Hemami, Sheila S
2003-01-01
Reversible integer wavelet transforms are increasingly popular in lossless image compression, as evidenced by their use in the recently developed JPEG2000 image coding standard. In this paper, a projection-based technique is presented for decreasing the first-order entropy of transform coefficients and improving the lossless compression performance of reversible integer wavelet transforms. The projection technique is developed and used to predict a wavelet transform coefficient as a linear combination of other wavelet transform coefficients. It yields optimal fixed prediction steps for lifting-based wavelet transforms and unifies many wavelet-based lossless image compression results found in the literature. Additionally, the projection technique is used in an adaptive prediction scheme that varies the final prediction step of the lifting-based transform based on a modeling context. Compared to current fixed and adaptive lifting-based transforms, the projection technique produces improved reversible integer wavelet transforms with superior lossless compression performance. It also provides a generalized framework that explains and unifies many previous results in wavelet-based lossless image compression.
Novel double phase transforming organogel based on β-cyclodextrin in 1,2-propylene glycol.
Liu, Wenqi; Xing, Pengyao; Xin, Feifei; Hou, Yuehui; Sun, Tao; Hao, Jingcheng; Hao, Aiyou
2012-11-01
This paper describes a novel double phase transforming organogel (gel-sol-gel') composed of nontoxic β-cyclodextrin, potassium carbonate, and 1,2-propylene glycol. The gel-sol-gel' transforming processes are followed by a reversible gel-sol transforming process and an irreversible sol-gel' transforming process based on heating. The gel-sol-gel' transformation is accompanied by microstructure changes from nanospheres to nanorods. K(2)CO(3) plays a key role in associating supramolecular architectures of β-cyclodextrin into a three-dimensional network. This work may bring further applications in the areas of smart materials, drug delivery systems, and biomaterials.
A NEW DNA BASED APPROACH OF GENERATING KEYDEPENDENTMIXCOLUMNS TRANSFORMATION
Directory of Open Access Journals (Sweden)
Auday H. Al-Wattar
2015-03-01
Full Text Available The use of key-dependent MixColumns can be regarded as one of the applied techniques for changing the quality of a cryptographic algorithm. This article explains one approach for altering the MixColumns transformation engaged in the AES algorithm. The approach employed methods inspired from DNA processes and structure, which relied on the key.The parameters of the proposedMixCloumns have characteristics identical to those of the original algorithm AES besides increasing its resistance against attack.The original transformation uses single static MDS matrix while the proposed methods used dynamic MDS. The security of the new MixColumns was analyzed, and the NIST Test Suite tests were used to test the randomness for the block cipher that used the new transformation.
A TRANSFORMATION APPROACH FOR COLLABORATION BASED REQUIREMENT MODELS
Directory of Open Access Journals (Sweden)
Ahmed Harbouche
2012-02-01
Full Text Available Distributed software engineering is widely recognized as a complex task. Among the inherent complexitiesis the process of obtaining a system design from its global requirement specification. This paper deals withsuch transformation process and suggests an approach to derive the behavior of a given systemcomponents, in the form of distributed Finite State Machines, from the global system requirements, in theform of an augmented UML Activity Diagrams notation. The process of the suggested approach issummarized in three steps: the definition of the appropriate source Meta-Model (requirements Meta-Model, the definition of the target Design Meta-Model and the definition of the rules to govern thetransformation during the derivation process. The derivation process transforms the global systemrequirements described as UML diagram activities (extended with collaborations to system rolesbehaviors represented as UML finite state machines. The approach is implemented using AtlasTransformation Language (ATL.
Realization of IIR Decimation Filters Based on Merged Delay Transformation
Directory of Open Access Journals (Sweden)
Umar Farooq
2007-01-01
The transformation is derived analytically and can be applied directly to first- and second-order IIR filters. Computational efficiency is enhanced because the current output can be directly computed from Mth old output. The output data rate is decreased by M by merging M number of delay elements in the recursive path. The proposed transformation is applied to higher-order IIR filter by decomposing it into parallel first-order and second-order sections. This transformation not only gives better stability for coefficient quantization but also reduces the requirement on processing clock, for sample, rate reduction. Filtering and down sampling are performed in the same stage. Number of multiplications is reduced by 45% as compared to the conventional IIR filters where all output samples are computed.
Image restoration based on the discrete fraction Fourier transform
Yan, Peimin; Mo, Yu L.; Liu, Hong
2001-09-01
The fractional Fourier transform is the powerful tool for time-variant signal analysis. For space-variant degradation and non-stationary processes the filtering in fractional Fourier domains permits reduction of the error compared with ordinary Fourier domain filtering. In this paper the concept of filtering in fractional Fourier domains is applied to the problem of estimating degraded images. Efficient digital implementation using discrete Hermite eigenvectors can provide similar results to match the continuous outputs. Expressions for the 2D optimal filter function in fractional domains will be given for transform domains characterized by the two rotation angle parameters of the 2D fractional Fourier transform. The proposed method is used to restore images that have several degradations in the experiments. The results show that the method presented in this paper is valid.
3-D surface profilometry based on modulation measurement by applying wavelet transform method
Zhong, Min; Chen, Feng; Xiao, Chao; Wei, Yongchao
2017-01-01
A new analysis of 3-D surface profilometry based on modulation measurement technique by the application of Wavelet Transform method is proposed. As a tool excelling for its multi-resolution and localization in the time and frequency domains, Wavelet Transform method with good localized time-frequency analysis ability and effective de-noizing capacity can extract the modulation distribution more accurately than Fourier Transform method. Especially for the analysis of complex object, more details of the measured object can be well remained. In this paper, the theoretical derivation of Wavelet Transform method that obtains the modulation values from a captured fringe pattern is given. Both computer simulation and elementary experiment are used to show the validity of the proposed method by making a comparison with the results of Fourier Transform method. The results show that the Wavelet Transform method has a better performance than the Fourier Transform method in modulation values retrieval.
A Plasma-Based DC-DC Electrical Transformer
Nebel, Richard; Finn, John
2013-10-01
Previous work has indicated that it may be possible to make DC-DC electrical transformers using plasmas. The mechanism is an MHD electromagnetic relaxation process induced by helical electrodes. This process is now being tested on the Bismark device at Tibbar Technologies.
Detection of K-complexes based on the wavelet transform
DEFF Research Database (Denmark)
Krohne, Lærke K.; Hansen, Rie B.; Christensen, Julie Anja Engelhard;
2014-01-01
Sleep scoring needs computational assistance to reduce execution time and to assure high quality. In this pilot study a semi-automatic K-Complex detection algorithm was developed using wavelet transformation to identify pseudo-K-Complexes and various feature thresholds to reject false positives...
Flexible Electronics-Based Transformers for Extreme Environments
Quadrelli, Marco B.; Stoica, Adrian; Ingham, Michel; Thakur, Anubhav
2015-01-01
This paper provides a survey of the use of modular multifunctional systems, called Flexible Transformers, to facilitate the exploration of extreme and previously inaccessible environments. A novel dynamics and control model of a modular algorithm for assembly, folding, and unfolding of these innovative structural systems is also described, together with the control model and the simulation results.
The Complexity of Transformation-Based Join Enumeration
Pellenkoft, A.J.; Galindo-Legaria, C.A.; Kersten, M.L.
1997-01-01
Query optimizers that explore a search space exhaustively using transformation rules usually apply all possible rules on each alternative, and stop when no new information is produced. A memoizing structure was proposed in [McKenna93] to improve the re-use of common subexpression, thus improving the
Nuclide identification algorithm based on K-L transform and neural networks
Energy Technology Data Exchange (ETDEWEB)
Chen Liang [Key Laboratory of Particle and Radiation Imaging (Tsinghua University), Department of Engineering Physics, Tsinghua University, Ministry of Education (China)], E-mail: cliang00@mails.tsinghua.edu.cn; Wei Yixiang [Key Laboratory of Particle and Radiation Imaging (Tsinghua University), Department of Engineering Physics, Tsinghua University, Ministry of Education (China)
2009-01-11
Traditional spectrum analysis algorithm based on peak search is hard to deal with complex overlapped peaks, especially in bad resolution and high background conditions. This paper described a new nuclide identification method based on the Karhunen-Loeve transform (K-L transform) and artificial neural networks. By the K-L transform and feature extraction, the nuclide gamma spectrum was compacted. The K-L transform coefficients were used as the neural network's input. The linear associative memory and ADALINE were discussed. Lots of experiments and tests showed that the method was credible and practical, especially suitable for fast nuclide identification.
Nuclide identification algorithm based on K-L transform and neural networks
Chen, Liang; Wei, Yi-Xiang
2009-01-01
Traditional spectrum analysis algorithm based on peak search is hard to deal with complex overlapped peaks, especially in bad resolution and high background conditions. This paper described a new nuclide identification method based on the Karhunen-Loeve transform (K-L transform) and artificial neural networks. By the K-L transform and feature extraction, the nuclide gamma spectrum was compacted. The K-L transform coefficients were used as the neural network's input. The linear associative memory and ADALINE were discussed. Lots of experiments and tests showed that the method was credible and practical, especially suitable for fast nuclide identification.
[Continuum based fast Fourier transform processing of infrared spectrum].
Liu, Qing-Jie; Lin, Qi-Zhong; Wang, Qin-Jun; Li, Hui; Li, Shuai
2009-12-01
To recognize ground objects with infrared spectrum, high frequency noise removing is one of the most important phases in spectrum feature analysis and extraction. A new method for infrared spectrum preprocessing was given combining spectrum continuum processing and Fast Fourier Transform (CFFT). Continuum was firstly removed from the noise polluted infrared spectrum to standardize hyper-spectra. Then the spectrum was transformed into frequency domain (FD) with fast Fourier transform (FFT), separating noise information from target information After noise eliminating from useful information with a low-pass filter, the filtered FD spectrum was transformed into time domain (TD) with fast Fourier inverse transform. Finally the continuum was recovered to the spectrum, and the filtered infrared spectrum was achieved. Experiment was performed for chlorite spectrum in USGS polluted with two kinds of simulated white noise to validate the filtering ability of CFFT by contrast with cubic function of five point (CFFP) in time domain and traditional FFT in frequency domain. A circle of CFFP has limited filtering effect, so it should work much with more circles and consume more time to achieve better filtering result. As for conventional FFT, Gibbs phenomenon has great effect on preprocessing result at edge bands because of special character of rock or mineral spectra, while works well at middle bands. Mean squared error of CFFT is 0. 000 012 336 with cut-off frequency of 150, while that of FFT and CFFP is 0. 000 061 074 with cut-off frequency of 150 and 0.000 022 963 with 150 working circles respectively. Besides the filtering result of CFFT can be improved by adjusting the filter cut-off frequency, and has little effect on working time. The CFFT method overcomes the Gibbs problem of FFT in spectrum filtering, and can be more convenient, dependable, and effective than traditional TD filter methods.
Strategic Choice on Transformation Mode of China¡¯s Resource-based Cities
Jinhuang Mao
2014-01-01
The industrial structure of the resource-based cities is relatively single. The ability to withstand macroeconomic risk is relatively weak. And with the depletion of resources, the issue of the transformation of the resource-based cities is becoming more and more urgent. Currently, researches focus mainly on the selection and developing of the leading industries of the resource-based cities. This is the goal and direction of the transformation in the resource-based cities, which is to be solv...
Wavelet Transform of Super-Resolutions Based on Radar and Infrared Sensor Fusion
1998-05-01
0I Q’UAL1 INwPO¶= I VI STATEMB r AApproved for public release; Distribution Unlimited NAVY CASE 77545 WAVELET TRANSFORM OF SUPER-RESOLUTIONS BASED ON...INVENTION It is, therefore, an object of the present invention to provide a structure and method for applying the forward and reverse Wavelet Transform (WT...invention, the noisy super- 10 resolution of infrared imaging is combined with the Wavelet transform for radar corner back-scattering size information
Finite Element Based Optimal Design Approach for High Voltage Pulse Transformers
Aguglia, D; Viarouge, P; Cros, J
2014-01-01
This paper presents an optimal design methodology of monolithic high voltage pulse transformers based on the direct 2D FEA identification of the electrical equivalent circuit parameters. This method is applied to the preliminary optimal design of the monolithic high voltage pulse transformer for the future CLIC modulators under study at CERN. The feasibility of such a transformer with tight specifications is demonstrated. The predicted performances obtained with the direct 2D FEA optimization process is validated by 3D FEA simulation.
Remotely sensed image compression based on wavelet transform
Kim, Seong W.; Lee, Heung K.; Kim, Kyung S.; Choi, Soon D.
1995-01-01
In this paper, we present an image compression algorithm that is capable of significantly reducing the vast amount of information contained in multispectral images. The developed algorithm exploits the spectral and spatial correlations found in multispectral images. The scheme encodes the difference between images after contrast/brightness equalization to remove the spectral redundancy, and utilizes a two-dimensional wavelet transform to remove the spatial redundancy. the transformed images are then encoded by Hilbert-curve scanning and run-length-encoding, followed by Huffman coding. We also present the performance of the proposed algorithm with the LANDSAT MultiSpectral Scanner data. The loss of information is evaluated by PSNR (peak signal to noise ratio) and classification capability.
The transverse Talbot effect: Scaling analyses based on wavelet transforms
Rosu, H C; Ludu, A
2013-01-01
Berry and Klein [J. Mod. Opt. 43, 2139 (1996)] studied the fractal properties of the paraxial diffracted field behind a Ronchi grating. In particular, they studied the transverse Talbot images formed at fractional distances in units of the Talbot distance chosen from the Fibonacci convergents to the complement of the inverse golden mean zeta_G=(3-square root of 5)/2. Here, we analyze these Talbot images with two well-known scaling methods, the wavelet transform modulus maxima (WTMM) and the wavelet transform multifractal detrended fluctuation analysis (WT-MFDFA). We use the widths of the singularity spectra, Delta(alpha)=alpha_H-alpha_min, as a characteristic feature of the Talbot images. The tau scaling exponents of the q moments are linear in q within the two methods, which is a strong argument in favor of the monofractality of the transverse diffractive paraxial field
Laser induced structural transformation in chalcogenide based superlattices
Zallo, Eugenio; Wang, Ruining; Bragaglia, Valeria; Calarco, Raffaella
2016-05-01
Superlattices made of alternating layers of nominal GeTe and Sb2Te3 have been studied by micro-Raman spectroscopy. A structural irreversible transformation into ordered GeSbTe alloy is induced by high power laser light exposure. The intensity ratio of anti-Stokes and Stokes scattering under laser illumination gives a maximum average temperature in the sample of 177 °C. The latter is lower than the growth temperature and of 400 °C necessary by annealing to transform the structure in a GeSbTe alloy. The absence of this configuration after in situ annealing even up to 300 °C evidences an electronic excitation induced-transition which brings the system into a different and stable crystalline state.
Robust Video Watermarking Based on Discrete Fractional Fourier Transform
Institute of Scientific and Technical Information of China (English)
NIU Xiamu; SUN Shenghe
2001-01-01
A video watermarking techniquebased on discrete fractional Fourier transform(DFRFT) is proposed. Each frame of an original videois first decomposed into two-dimensional (2-D) mul-tiresolution representations by 2-D discrete wavelettransforms (DWT) along the spatial axis. Then thewavelet coefficient frames in each group of pictures(GOP, each GOP has 16 frames) are transformed intoDFRFT coefficient frames by one-dimensional (1-D)DFRFT along the temporal axis. The watermark isembedded into each DFRFT coefficient frame in theGOP, and the angular parameter of the DFRFT canbe changed to adapt itself to the original video. Experimental results show that the proposed techniqueis robust enough against the attacks of frame dropping, averaging and lossy compression.
Ohtsuka, Hideyuki
2008-01-01
A magnetic field has a remarkable influence on solid/solid phase transformations and it can be used to control the structure and function of materials during phase transformations. The effects of magnetic fields on diffusional solid/solid phase transformations, mainly from austenite to ferrite, in Fe-based alloys are reviewed. The effects of magnetic fields on the transformation temperature and phase diagram are explained thermodynamically, and the transformation behavior and transformed structures in magnetic fields are discussed.
Speckle reduction algorithm for laser underwater image based on curvelet transform
Institute of Scientific and Technical Information of China (English)
Wei Ni; Baolong Guo; Liu Yang; Peiyan Fei
2006-01-01
@@ Based on the analysis on the statistical model of speckle noise in laser underwater image, a novel speckle reduction algorithm using curvelet transform is proposed. Logarithmic transform is performed to transform the original multiplicative speckle noise into additive noise. An improved hard thresholding algorithm is applied in curvelet transform domain. The classical Monte-Carlo method is adopted to estimate the statistics of contourlet coefficients for speckle noise, thus determining the optimal threshold set. To further improve the visual quality of despeckling laser image, the cycle spinning technique is also utilized. Experimental results show that the proposed algorithm can achieve better performance than classical wavelet method and maintain more detail information.
Digital Image Scrambling Technology Based on the Symmetry of Arnold Transform
Institute of Scientific and Technical Information of China (English)
YANG Ya-li; CAI Na; NI Guo-qiang
2006-01-01
An improved digital image scrambling method based on Arnold transform is proposed. The method can be used for the rectangle image by splitting rectangle image into several square images. Furthermore, a pretreatment is added to speeding up the process and enhancing the scrambling effect. The recovering of the scrambled image depends on the reverse Arnold transform that has the same cycle times with the Arnold transform. The recovering is lossless and need not calculating the period of the Arnold transform. Finally, experimental results show the robustness of the method.
Investigation on the Electrical Conductivity of Transformer Oil-Based AlN Nanofluid
Directory of Open Access Journals (Sweden)
M. Dong
2013-01-01
Full Text Available Aluminum-nitride-(AlN-transformer oil-based nanofluid was prepared by dispersing AlN nanoparticles in transformer oil. The composition-dependent electrical conductivity of AlN-transformer oil nanofluid was investigated at different ambient temperatures. The results indicate the nonlinear dependences of the electrical conductivity on volumetric fraction and temperature. In comparison to the pure transformer oil, the electrical conductivity of nanofluid containing 0.5% AlN nanoparticles has increased by 1057 times at 60°C. By considering the electrophoresis of the AlN nanoparticles, a straightforward electrical conductivity model is established to modulate and understand the experiment results.
DEFF Research Database (Denmark)
Zhurbenko, Vitaliy; Krozer, Viktor; Meincke, Peter
2007-01-01
A new broadband quarter-wavelength impedance transformer based on an asymmetric coupled line section is presented. The bandwidth of the coupled line transformer is extended with the help of an interconnecting transmission line. An analytical model for the transformer is developed. The analysis...... of the structure reveals that a fractional bandwidth of more than 100% at –20 dB reflection level can be achieved with such a structure. An experimental transformer circuit has been designed, fabricated and tested. Theoretical and experimental results are fair agreement and confirm the established theory...
The Need for Transformational Leadership in Singapore's School-Based Reform
Retna, Kala S.; Ng, Pak Tee
2009-01-01
In Singapore, "decentralization" and "school-based reforms" are key words within the current education reform agenda. This article argues that a key success factor in this agenda is transformational leadership in school. With more autonomy given to the school, transformational leadership at the school level will facilitate the…
Digital watermarking for still image based on discrete fractional fourier transform
Institute of Scientific and Technical Information of China (English)
无
2001-01-01
Presents a digital watermarking technique based on discrete fractional Fourier transform(DFRFT), discusses the transformation of the original image by DFRFT, and the modification of DFRFT coefficients of the original image by the information of watermark, and concludes from experimental results that the proposed tech nique is robust to lossy compression attack.
The Need for Transformational Leadership in Singapore's School-Based Reform
Retna, Kala S.; Ng, Pak Tee
2009-01-01
In Singapore, "decentralization" and "school-based reforms" are key words within the current education reform agenda. This article argues that a key success factor in this agenda is transformational leadership in school. With more autonomy given to the school, transformational leadership at the school level will facilitate the…
DEFF Research Database (Denmark)
S. El Moursi, Mohamed; Bak-Jensen, Birgitte; Abdel-Rahman, Mansour Hassan
2011-01-01
and optimal tracking secondary voltage control for wind parks based on self-excited induction generators which comprise STATCOM and under-load tap changer (ULTC) substation transformers. The voltage controllers for the STATCOM and ULTC transformer are coordinated and ensure the voltage support. In steady...
A physically based model for the isothermal martensitic transformation in a maraging steel
Kruijver, S. O.; Blaauw, H. S.; Beyer, J.; Post, J.
2003-10-01
Isothermal transformation from austenite to martensite in steel products during or after the production process often show residual stresses which can create unacceptable dimensional changes in the final product. Tn order to gain more insight in the effects infiuencing the isothermai transformation, the overall kinetics in a low Carbon-Nickel maraging steel is investigated. The influence of the austenitizing température, time and quenching rate on the transformation is measured magnetically and yields information about the transformation rate and final amount of transformation. A physically based model describing the nucleation and growth of martensite is used to explain the observed effects. The results show a very good fit of the experimental values and the model description of the transformation, within the limitations of the inhomogeneities (carbides and intermetallics, size and distribution in the material and stress state) and experimental conditions.
Calculation Scheme Based on a Weighted Primitive: Application to Image Processing Transforms
Directory of Open Access Journals (Sweden)
Gregorio de Miguel Casado
2007-01-01
Full Text Available This paper presents a method to improve the calculation of functions which specially demand a great amount of computing resources. The method is based on the choice of a weighted primitive which enables the calculation of function values under the scope of a recursive operation. When tackling the design level, the method shows suitable for developing a processor which achieves a satisfying trade-off between time delay, area costs, and stability. The method is particularly suitable for the mathematical transforms used in signal processing applications. A generic calculation scheme is developed for the discrete fast Fourier transform (DFT and then applied to other integral transforms such as the discrete Hartley transform (DHT, the discrete cosine transform (DCT, and the discrete sine transform (DST. Some comparisons with other well-known proposals are also provided.
Zhang, Yushu; Xiao, Di; Wen, Wenying; Tian, Yuan
2013-12-01
In some special multimedia applications, only the regions with semantic information should be provided better protection whereas the other smooth regions can be free of encryption. However, most of the existing multimedia security schemes only consider bits and pixels rather than semantic information during their encryption. Motivated by this, we propose an edge-based lightweight image encryption scheme using chaos-based reversible hidden transform and multiple-order discrete fractional cosine transform. An image is first carried out by the edge detection based on advanced CNN structure with adaptive thresholds to assess data significance in the image. The detection output is a binary image, in which a “1” reflects the detected pixel whereas a “0” is opposite. Both the detected image and the original image are divided into non-overlapping pixel blocks in the same way, respectively. Whether each block is encrypted or not depends on the significance judged by the corresponding detected block. The significant block is performed by reversible hidden transform followed by multiple-order discrete fractional cosine transform parameters and orders of these two transforms are determined by a two dimensional cross chaotic map. Experiment results show the significant contour features of an image that have been largely hidden only by encrypting about half pixels in the average sense. The keys are extremely sensitive and the proposed scheme can resist noise attack to some extent.
Human Body Image Edge Detection Based on Wavelet Transform
Institute of Scientific and Technical Information of China (English)
李勇; 付小莉
2003-01-01
Human dresses are different in thousands way.Human body image signals have big noise, a poor light and shade contrast and a narrow range of gray gradation distribution. The application of a traditional grads method or gray method to detect human body image edges can't obtain satisfactory results because of false detections and missed detections. According to tte peculiarity of human body image, dyadic wavelet transform of cubic spline is successfully applied to detect the face and profile edges of human body image and Mallat algorithm is used in the wavelet decomposition in this paper.
High Capacity Secure Image Steganography Based on Contourlet Transform
Directory of Open Access Journals (Sweden)
Kolsoom Shahryari
2013-09-01
Full Text Available In this paper we propose an image steganography technique which embeds secret data without making explicit modifications to the image. The proposed method simultaneously provides both imperceptibility and undetectability. We decompose image by contourlet transform and determine nonsmooth regions. Embedding data in these regions cause less degradation in image quality. Contourlet sub-bands are divided into 3×3 blocks. Central coefficient of each block is considered for embedding if they belong to edgy regions. Experiments show that this method can achieve high embedding capacity while remains undetectable by Farid's universal steganalysis technique.
Chaotic Synchronization with Filter Based on Wavelet Transformation
Institute of Scientific and Technical Information of China (English)
XiaoanZHOU; JunfengLAN; 等
1999-01-01
A kind of chaotic synchronization method is presented in the paper,In the transmitter,part signals are transformed by wavelet and the detail information is removed.In the receiver.the component with low frequency is reconstructed and discrete feedback is used,we show that synchronization of two identical structure chaotic systems is attained.The effect of feedback on chaotic synchronization is discussed.Using the synchronous method,the transmitting signal is transported in compressible way system resource is saved,the component with high frequency is filtered and the effect of disturbance on synchronization is reduced.The synchronization method is illustrated by numerical simulation experiment.
Polyethylene Glycol-Mediated Synthesis of Cubic Iron Oxide Nanoparticles with High Heating Power
Iacovita, Cristian; Stiufiuc, Rares; Radu, Teodora; Florea, Adrian; Stiufiuc, Gabriela; Dutu, Alina; Mican, Sever; Tetean, Romulus; Lucaciu, Constantin M.
2015-10-01
Iron oxide magnetic nanoparticles (IOMNPs) have been successfully synthesized by means of solvothermal reduction method employing polyethylene glycol (PEG200) as a solvent. The as-synthesized IOMNPs are poly-dispersed, highly crystalline, and exhibit a cubic shape. The size of IOMNPs is strongly dependent on the reaction time and the ration between the amount of magnetic precursor and PEG200 used in the synthesis method. At low magnetic precursor/PEG200 ratio, the cubic IOMNPs coexist with polyhedral IOMNPs. The structure and morphology of the IOMNPs were thoroughly investigated by using a wide range of techniques: TEM, XRD, XPS, FTIR, and RAMAN. XPS analysis showed that the IOMNPs comprise a crystalline magnetite core bearing on the outer surface functional groups from PEG200 and acetate. The presence of physisorbed PEG200 on the IOMNP surface is faintly detected through FT-IR spectroscopy. The surface of IOMNPs undergoes oxidation into maghemite as proven by RAMAN spectroscopy and the occurrence of satellite peaks in the Fe2p XP spectra. The magnetic studies performed on powder show that the blocking temperature (TB) of IOMNPs is around 300 K displaying a coercive field in between 160 and 170 Oe. Below the TB, the field-cooled (FC) curves turn concave and describe a plateau indicating that strong magnetic dipole-dipole interactions are manifested in between IOMNPs. The specific absorption rate (SAR) values increase with decreasing nanoparticle concentrations for the IOMNPs dispersed in water. The SAR dependence on the applied magnetic field, studied up to magnetic field amplitude of 60 kA/m, presents a sigmoid shape with saturation values up to 1700 W/g. By dispersing the IOMNPs in PEG600 (liquid) and PEG1000 (solid), it was found that the SAR values decrease by 50 or 75 %, indicating that the Brownian friction within the solvent was the main contributor to the heating power of IOMNPs.
Quantum Image Encryption Based on Iterative Framework of Frequency-Spatial Domain Transforms
Wang, Han; Wang, Jian; Geng, Ya-Cong; Song, Yan; Liu, Ji-Qiang
2017-10-01
A novel quantum image encryption and decryption algorithm based on iteration framework of frequency-spatial domain transforms is proposed. In this paper, the images are represented in the flexible representation for quantum images (FRQI). Previous quantum image encryption algorithms are realized by spatial domain transform to scramble the position information of original images and frequency domain transform to encode the color information of images. But there are some problems such as the periodicity of spatial domain transform, which will make it easy to recover the original images. Hence, we present the iterative framework of frequency-spatial domain transforms. Based on the iterative framework, the novel encryption algorithm uses Fibonacci transform and geometric transform for many times to scramble the position information of the original images and double random-phase encoding to encode the color information of the images. The encryption keys include the iterative time t of the Fibonacci transform, the iterative time l of the geometric transform, the geometric transform matrix G i which is n × n matrix, the classical binary sequences K (k0k1{\\ldots } k_{2^{2n}-1}) and D(d0d1{\\ldots } d_{2^{2n}-1}). Here the key space of Fibonacci transform and geometric transform are both estimated to be 226. The key space of binary sequences is (2 n× n ) × (2 n× n ). Then the key space of the entire algorithm is about 2^{2{n2}+52}. Since all quantum operations are invertible, the quantum image decryption algorithm is the inverse of the encryption algorithm. The results of numerical simulation and analysis indicate that the proposed algorithm has high security and high sensitivity.
Artifact-Based Transformation of IBM Global Financing
Chao, Tian; Cohn, David; Flatgard, Adrian; Hahn, Sandy; Linehan, Mark; Nandi, Prabir; Nigam, Anil; Pinel, Florian; Vergo, John; Wu, Frederick Y.
IBM Global Financing (IGF) is transforming its business using the Business Artifact Method, an innovative business process modeling technique that identifies key business artifacts and traces their life cycles as they are processed by the business. IGF is a complex, global business operation with many business design challenges. The Business Artifact Method is a fundamental shift in how to conceptualize, design and implement business operations. The Business Artifact Method was extended to solve the problem of designing a global standard for a complex, end-to-end process while supporting local geographic variations. Prior to employing the Business Artifact method, process decomposition, Lean and Six Sigma methods were each employed on different parts of the financing operation. Although they provided critical input to the final operational model, they proved insufficient for designing a complete, integrated, standard operation. The artifact method resulted in a business operations model that was at the right level of granularity for the problem at hand. A fully functional rapid prototype was created early in the engagement, which facilitated an improved understanding of the redesigned operations model. The resulting business operations model is being used as the basis for all aspects of business transformation in IBM Global Financing.
[Fourier Transform Spectrometer Based on Rotating Parallel-Mirror-Pair].
Zhao, Bao-wei; Xiangli, Bin; Cai, Qi-sheng; Lü, Qun-bo; Zhou, Jin-song
2015-11-01
In the temporally-modulated Fourier transform spectroscopy, the translational moving mirror is difficult to drive accurately, causing tilt and shear problems. While, a rotational moving mirror can solve these problems. A rotary Fourier transform spectrometer is recommanded in this paper. Its principle is analyzed and the optical path difference is deduced. Also, the constrains for engineering realization are presented. This spectrometer consists of one beamsplitter, two fixed mirrors, one rotating parallel mirror pair, a collimating lens, a collecting lens, and one detector. From it's principle, this spectrometer show a simple structure, and it is assembled and adjustmented easily because the two split light are interfered with each other after reflected through the same plane mirror; By calculating the expression of it's optical path difference, the spectrometer is easy to realize large optical path difference, meaning high spectral resolution; Through analyzing it's engineering design constraints and computer simulation, it is known that the spectrometer should get the high resolution sample by high-speed spinning motor, so it is easy to achieve precise motion control, good stability, fast measurement speed.
All-optical image processing and compression based on Haar wavelet transform.
Parca, Giorgia; Teixeira, Pedro; Teixeira, Antonio
2013-04-20
Fast data processing and compression methods based on wavelet transform are fundamental tools in the area of real-time 2D data/image analysis, enabling high definition applications and redundant data reduction. The need for information processing at high data rates motivates the efforts on exploiting the speed and the parallelism of the light for data analysis and compression. Among several schemes for optical wavelet transform implementation, the Haar transform offers simple design and fast computation, plus it can be easily implemented by optical planar interferometry. We present an all optical scheme based on an asymmetric couplers network for achieving fast image processing and compression in the optical domain. The implementation of Haar wavelet transform through a 3D passive structure is supported by theoretical formulation and simulations results. Asymmetrical coupler 3D network design and optimization are reported and Haar wavelet transform, including compression, was achieved, thus demonstrating the feasibility of our approach.
Directory of Open Access Journals (Sweden)
Wei Bengang
2016-01-01
Full Text Available In this paper, the different types of discharge in transformer were simulated based on the real transformer fault model. The optical partial discharge detection system was established based on optical sensors which were capturing partial discharge accompanied by optical effects. In this research, surface discharge and suspended discharge defect model was pressurized to generate partial discharge signal. The results showed that: Partial discharge optical signals could effectively respond the production and development process of transformer partial discharge. It was able to assess discharge level also. When the discharge phenomenon stabilized, the phase of surface discharge mainly between 60°~150°and 240°~330°, the phase of suspended discharge mainly between 260°~320°. According to the phase characteristic of discharge pattern, the creeping discharge and suspended discharge phenomenon of transformer can be distinguished. It laid the foundation for the application of transformer optical partial discharge detection technology.
Fast heap transform-based QR-decomposition of real and complex matrices: algorithms and codes
Grigoryan, Artyom M.
2015-03-01
In this paper, we describe a new look on the application of Givens rotations to the QR-decomposition problem, which is similar to the method of Householder transformations. We apply the concept of the discrete heap transform, or signal-induced unitary transforms which had been introduced by Grigoryan (2006) and used in signal and image processing. Both cases of real and complex nonsingular matrices are considered and examples of performing QR-decomposition of square matrices are given. The proposed method of QR-decomposition for the complex matrix is novel and differs from the known method of complex Givens rotation and is based on analytical equations for the heap transforms. Many examples illustrated the proposed heap transform method of QR-decomposition are given, algorithms are described in detail, and MATLAB-based codes are included.
Property study of integer wavelet transform lossless compression coding based on lifting scheme
Xie, Cheng Jun; Yan, Su; Xiang, Yang
2006-01-01
In this paper the algorithms and its improvement of integer wavelet transform combining SPIHT and arithmetic coding in image lossless compression is mainly studied. The experimental result shows that if the order of low-pass filter vanish matrix is fixed, the improvement of compression effect is not evident when invertible integer wavelet transform is satisfied and focusing of energy property monotonic increase with transform scale. For the same wavelet bases, the order of low-pass filter vanish matrix is more important than the order of high-pass filter vanish matrix in improving the property of image compression. Integer wavelet transform lossless compression coding based on lifting scheme has no relation to the entropy of image. The effect of compression is depended on the the focuing of energy property of image transform.
Ogawa, Takahiro; Haseyama, Miki
2013-03-01
A missing texture reconstruction method based on an error reduction (ER) algorithm, including a novel estimation scheme of Fourier transform magnitudes is presented in this brief. In our method, Fourier transform magnitude is estimated for a target patch including missing areas, and the missing intensities are estimated by retrieving its phase based on the ER algorithm. Specifically, by monitoring errors converged in the ER algorithm, known patches whose Fourier transform magnitudes are similar to that of the target patch are selected from the target image. In the second approach, the Fourier transform magnitude of the target patch is estimated from those of the selected known patches and their corresponding errors. Consequently, by using the ER algorithm, we can estimate both the Fourier transform magnitudes and phases to reconstruct the missing areas.
Waste Heat Power Generation Technology of Steelmaking EAF%炼钢电炉余热发电技术
Institute of Scientific and Technical Information of China (English)
何立波
2013-01-01
The waste heat condition of flue gas in steelmaking EAF and the project examples of waste heat power generation were introduced. The technologies of gas pulse soot blowing, steam accumulator and saturated steam generation were used to solve the waste heat recovery problem in the project. The waste heat was hard to recovery because of the overmuch dust and big waste heat fluctuation in the waste heat power generation system of the steelmaking EAF.%介绍了炼钢电炉烟气的余热情况及其余热发电的项目实例.项目利用燃气脉冲吹灰、蒸汽蓄能及饱和蒸汽发电技术,解决炼钢电炉烟气余热发电系统中因烟气含尘多和余热波动大而难于回收利用的问题.
A Steganographic Method Based on Integer Wavelet Transform & Genatic Algorithm
Directory of Open Access Journals (Sweden)
Preeti Arora
2014-05-01
Full Text Available The proposed system presents a novel approach of building a secure data hiding technique of steganography using inverse wavelet transform along with Genetic algorithm. The prominent focus of the proposed work is to develop RS-analysis proof design with higest imperceptibility. Optimal Pixal Adjustment process is also adopted to minimize the difference error between the input cover image and the embedded-image and in order to maximize the hiding capacity with low distortions respectively. The analysis is done for mapping function, PSNR, image histogram, and parameter of RS analysis. The simulation results highlights that the proposed security measure basically gives better and optimal results in comparison to prior research work conducted using wavelets and genetic algorithm.
Steganography Based on Integer Wavelet Transform and Bicubic Interpolation
Directory of Open Access Journals (Sweden)
N. Ajeeshvali
2012-11-01
Full Text Available Steganography is the art and science of hiding information in unremarkable cover media so as not to observe any suspicion. It is an application under information security field, being classified under information security, Steganography will be characterized by having set of measures that rely on strengths and counter attacks that are caused by weaknesses and vulnerabilities. The aim of this paper is to propose a modified high capacity image steganography technique that depends on integer wavelet transform with acceptable levels of imperceptibility and distortion in the cover image as a medium file and high levels of security. Bicubic interpolation causes overshoot, which increases acutance (apparent sharpness. The Bicubic algorithm is frequently used for scaling images and video for display. The algorithm preserves fine details of the image better than the common bilinear algorithm.
NONSUBSAMPLED CONTOURLET TRANSFORM BASED CLASSIFICATION OF MICROCALCIFICATION IN DIGITAL MAMMOGRAMS
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J. S. Leena Jasmine
2013-01-01
Full Text Available Mammogram is the best available radiographic method to detect breast cancer in the early stage. However detecting a microcalcification clusters in the early stage is a tough task for the radiologist. Herein we present a novel approach for classifying microcalcification in digital mammograms using Nonsubsampled Contourlet Transform (NSCT and Support Vector Machine (SVM. The classification of microcalcification is achieved by extracting the microcalcification features from the Contourlet coefficients of the image and the outcomes are used as an input to the SVM for classification. The system classifies the mammogram images as normal or abnormal and the abnormal severity as benign or malignant. The evaluation of the system is carried on using Mammography Image Analysis Society (MIAS database. The experimental result shows that the proposed method provides improved classification rate.
Sunlight-induced Transformations of Graphene-based Nanomaterials in Aquatic Environments
Graphene-based nanomaterials and other related carbon nanomaterials (CNMs) can be released from products during their life cycles. Upon entry into aquatic environments, they are potentially transformed by photochemical reactions, oxidation reactions and biological processes, all ...
Belazi, Akram; Abd El-Latif, Ahmed A.; Diaconu, Adrian-Viorel; Rhouma, Rhouma; Belghith, Safya
2017-01-01
In this paper, a new chaos-based partial image encryption scheme based on Substitution-boxes (S-box) constructed by chaotic system and Linear Fractional Transform (LFT) is proposed. It encrypts only the requisite parts of the sensitive information in Lifting-Wavelet Transform (LWT) frequency domain based on hybrid of chaotic maps and a new S-box. In the proposed encryption scheme, the characteristics of confusion and diffusion are accomplished in three phases: block permutation, substitution, and diffusion. Then, we used dynamic keys instead of fixed keys used in other approaches, to control the encryption process and make any attack impossible. The new S-box was constructed by mixing of chaotic map and LFT to insure the high confidentiality in the inner encryption of the proposed approach. In addition, the hybrid compound of S-box and chaotic systems strengthened the whole encryption performance and enlarged the key space required to resist the brute force attacks. Extensive experiments were conducted to evaluate the security and efficiency of the proposed approach. In comparison with previous schemes, the proposed cryptosystem scheme showed high performances and great potential for prominent prevalence in cryptographic applications.
Institute of Scientific and Technical Information of China (English)
Wang Dun-Hui; Han Zhi-Da; Xuan Hai-Cheng; Ma Sheng-Can; Chen Shui-Yuan; Zhang Cheng-Liang; Du You-Wei
2013-01-01
Ferromagnetic shape memory alloys,which undergo the martensitic transformation,are famous multifunctional materials.They exhibit many interesting magnetic properties around the martensitic transformation temperature due to the strong coupling between magnetism and structure.Tuning magnetic phase transition and optimizing the magnetic effects in these alloys are of great importance.In this paper,the regulation of martensitic transformation and the investigation of some related magnetic effects in Ni-Mn-based alloys are reviewed based on our recent research results.
Optical phase extraction algorithm based on the continuous wavelet and the Hilbert transforms
Bahich, Mustapha; Barj, Elmostafa
2010-01-01
In this paper we present an algorithm for optical phase evaluation based on the wavelet transform technique. The main advantage of this method is that it requires only one fringe pattern. This algorithm is based on the use of a second {\\pi}/2 phase shifted fringe pattern where it is calculated via the Hilbert transform. To test its validity, the algorithm was used to demodulate a simulated fringe pattern giving the phase distribution with a good accuracy.
Institute of Scientific and Technical Information of China (English)
CHEN Lin-Fei; ZHAO Dao-Mu
2006-01-01
@@ We propose a new method to add different images together by optical implementation that is realized by the multi-exposure based on fractional Fourier transform hologram. Partial image fusion is proposed and realized by this method. Multiple images encryption can also be implemented by the multi-exposure of the hologram based on fractional Fourier transform. Computer simulations prove that this method is valid.
Dong, Jian; Kudo, Hiroyuki
2017-03-01
Compressed sensing (CS) is attracting growing concerns in sparse-view computed tomography (CT) image reconstruction. The most standard approach of CS is total variation (TV) minimization. However, images reconstructed by TV usually suffer from distortions, especially in reconstruction of practical CT images, in forms of patchy artifacts, improper serrate edges and loss of image textures. Most existing CS approaches including TV achieve image quality improvement by applying linear transforms to object image, but linear transforms usually fail to take discontinuities into account, such as edges and image textures, which is considered to be the key reason for image distortions. Actually, discussions on nonlinear filter based image processing has a long history, leading us to clarify that the nonlinear filters yield better results compared to linear filters in image processing task such as denoising. Median root prior was first utilized by Alenius as nonlinear transform in CT image reconstruction, with significant gains obtained. Subsequently, Zhang developed the application of nonlocal means-based CS. A fact is gradually becoming clear that the nonlinear transform based CS has superiority in improving image quality compared with the linear transform based CS. However, it has not been clearly concluded in any previous paper within the scope of our knowledge. In this work, we investigated the image quality differences between the conventional TV minimization and nonlinear sparsifying transform based CS, as well as image quality differences among different nonlinear sparisying transform based CSs in sparse-view CT image reconstruction. Additionally, we accelerated the implementation of nonlinear sparsifying transform based CS algorithm.
A hyperspectral images compression algorithm based on 3D bit plane transform
Zhang, Lei; Xiang, Libin; Zhang, Sam; Quan, Shengxue
2010-10-01
According the analyses of the hyper-spectral images, a new compression algorithm based on 3-D bit plane transform is proposed. The spectral coefficient is higher than the spatial. The algorithm is proposed to overcome the shortcoming of 1-D bit plane transform for it can only reduce the correlation when the neighboring pixels have similar values. The algorithm calculates the horizontal, vertical and spectral bit plane transform sequentially. As the spectral bit plane transform, the algorithm can be easily realized by hardware. In addition, because the calculation and encoding of the transform matrix of each bit are independent, the algorithm can be realized by parallel computing model, which can improve the calculation efficiency and save the processing time greatly. The experimental results show that the proposed algorithm achieves improved compression performance. With a certain compression ratios, the algorithm satisfies requirements of hyper-spectral images compression system, by efficiently reducing the cost of computation and memory usage.
Prediction of the breakdown voltage of transformer oil based on a backpropagation network
Energy Technology Data Exchange (ETDEWEB)
Cao Shun' an; Li Rui; Sheng Kai [Wuhan Univ., Hubei Province (China). Dept. of Water Quality Engineering
2008-03-15
Prediction of the breakdown voltage of transformer oil facilitates the early fault diagnosis of transformers, and provides a scientific basis for the prevention of faults in transformer oil. In this paper, based on the correlation between performance parameters of transformer oil, along with the excellent fault-tolerant ability, prominent non-linear approximation capability and self-learning capacity of backpropagation (BP) networks, a BP network with a BP algorithm and a BP network with an improved BP algorithm are developed to simulate the correlation between breakdown voltage and four relevant parameters, using the monitoring data of transformer oil. The results show that the latter algorithm gives more accurate predicted values, which proves to be of high application value. (orig.)
Institute of Scientific and Technical Information of China (English)
廖力清; 曾可; 凌玉华; 杨欣荣; 陈燕辉
2001-01-01
In nickel smelting process, the working conditions and surroundings for the transformer of electric furnace are worse than general electric power transformer. It is difficult to meet the requirements on reliability and safety by the conventional centralized control protection. With the development of microcomputer and field-bus technology, it is necessary to design a new type of protection and monitoring system for transformer of electric furnace. A microprocessor-based protection and monitoring system was described, which uses the embedded high performance microprocessor 87C196KC20 as its most important micro-controller unit & the technology of CAN (Controller Area Network) making it a fully distributed microcomputer system not only to perform all sorts of the transformer protection and function of automatic coinciding and communicate with the monitoring host, but also to carry with it the function of protecting, measuring, and fault diagnosis for transformer of electric furnace.
Directory of Open Access Journals (Sweden)
Lei Wang
2015-09-01
Full Text Available Based on fractal geometry, fractal medium of coalbed methane mathematical model is established by Langmuir isotherm adsorption formula, Fick's diffusion law, Laplace transform formula, considering the well bore storage effect and skin effect. The Laplace transform finite difference method is used to solve the mathematical model. With Stehfest numerical inversion, the distribution of dimensionless well bore flowing pressure and its derivative was obtained in real space. According to compare with the results from the analytical method, the result from Laplace transform finite difference method turns out to be accurate. The influence factors are analyzed, including fractal dimension, fractal index, skin factor, well bore storage coefficient, energy storage ratio, interporosity flow coefficient and the adsorption factor. The calculating error of Laplace transform difference method is small. Laplace transform difference method has advantages in well-test application since any moment simulation does not rely on other moment results and space grid.
Online Botnet Detection Based on Incremental Discrete Fourier Transform
Directory of Open Access Journals (Sweden)
Xiaocong Yu
2010-05-01
Full Text Available Botnet detection has attracted lots of attention since botnet attack is becoming one of the most serious threats on the Internet. But little work has considered the online detection. In this paper, we propose a novel approach that can monitor the botnet activities in an online way. We define the concept of “feature streams” to describe raw network traffic. If some feature streams show high similarities, the corresponding hosts will be regarded as suspected bots which will be added into the suspected bot hosts set. After activity analysis, bot hosts will be confirmed as soon as possible. We present a simple method by computing the average Euclidean distance for similarity measurement. To avoid huge calculation among feature streams, classical Discrete Fourier Transform (DFT technique is adopted. Then an incremental calculation of DFT coefficients is introduced to obtain the optimal execution time. The experimental evaluations show that our approach can detect both centralized and distributed botnet activities successfully with high efficiency and low false positive rate.
Surface Electromyography Feature Extraction Based on Wavelet Transform
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Farzaneh Akhavan Mahdavi
2012-12-01
Full Text Available Considering the vast variety of EMG signal applications such as rehabilitation of people suffering from some mobility limitations, scientists have done much research on EMG control system. In this regard, feature extraction of EMG signal has been highly valued as a significant technique to extract the desired information of EMG signal and remove unnecessary parts. In this study, Wavelet Transform (WT has been applied as the main technique to extract Surface EMG (SEMG features because WT is consistent with the nature of EMG as a nonstationary signal. Furthermore, two evaluation criteria, namely, RES index (the ratio of a Euclidean distance to a standard deviation and scatter plot are recruited to investigate the efficiency of wavelet feature extraction. The results illustrated an improvement in class separability of hand movements in feature space. Accordingly, it has been shown that only the SEMG features extracted from first and second level of WT decomposition by second order of Daubechies family (db2 yielded the best class separability.
Discrete-cosine-transform-based image compression applied to dermatology
Cookson, John P.; Sneiderman, Charles; Rivera, Christopher
1991-05-01
The research reported in this paper concerns an evaluation of the impact of compression on the quality of digitized color dermatologic images. 35 mm slides of four morphologic types of skin lesions were captured at 1000 pixels per inch (ppi) in 24 bit RGB color, to give an approximate 1K X 1K image. The discrete cosine transform (DCT) algorithm, was applied to the resulting image files to achieve compression ratios of about 7:1, 28:1, and 70:1. The original scans and the decompressed files were written to a 35 mm film recorder. Together with the original photo slides, the slides resulting from digital images were evaluated in a study of morphology recognition and image quality assessment. A panel of dermatologists was asked to identify the morphology depicted and to rate the image quality of each slide. The images were shown in a progression from highest level of compression to original photo slides. We conclude that the use of DCT file compression yields acceptable performance for skin lesion images since differences in morphology recognition performance do not correlate significantly with the use of original photos versus compressed versions. Additionally, image quality evaluation does not correlate significantly with level of compression.
Design and Implementation of Fast- Lifting Based Wavelet Transform for Image Compression
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Lokesh B.S
2014-06-01
Full Text Available The digital data can be compressed and retrieved using Discrete Wavelet Transform (DWT and Inverse Discrete wavelet Transform (IDWT. The medical images need to be compressed and retrieved without loosing of information. The Discrete Wavelet Transform (DWT is based on time-scale representation which provides efficient multi-resolution. This paper mainly describes the lifting based scheme gives lossless mode of information. The lifting based DWT and IDWT are having lower computational complexity and reduced memory requirement. Conventional convolution based DWT and IDWT are area and power hungry. These drawbacks can be overcome by using the lifting based scheme. This system adopts lifting based scheme DWT and IDWT which gives the lossless information of the data, reduces the complexity and optimized in area and power. In this research the DWT and IDWT are simulated and the design of hardware model is carried out using RTL level coding.
Energy Technology Data Exchange (ETDEWEB)
Eldin, A.A. Hossam; Refaey, M.A. [Electrical Engineering Department, Alexandria University, Alexandria (Egypt)
2011-01-15
This paper proposes a novel methodology for transformer differential protection, based on wave shape recognition of the discriminating criterion extracted of the instantaneous differential currents. Discrete wavelet transform has been applied to the differential currents due to internal fault and inrush currents. The diagnosis criterion is based on median absolute deviation (MAD) of wavelet coefficients over a specified frequency band. The proposed algorithm is examined using various simulated inrush and internal fault current cases on a power transformer that has been modeled using electromagnetic transients program EMTDC software. Results of evaluation study show that, proposed wavelet based differential protection scheme can discriminate internal faults from inrush currents. (author)
Gan, Shuwei; Wang, Shoudong; Chen, Yangkang; Chen, Xiaohong; Huang, Weiling; Chen, Hanming
2016-07-01
According to the compressive sensing (CS) theory in the signal-processing field, we proposed a new CS approach based on a fast projection onto convex sets (POCS) algorithm with sparsity constraint in the seislet transform domain. The seislet transform appears to be the sparest among the state-of-the-art sparse transforms. The FPOCS can obtain much faster convergence than conventional POCS (about two thirds of conventional iterations can be saved), while maintaining the same recovery performance. The FPOCS can obtain faster and better performance than FISTA for relatively cleaner data but will get slower and worse performance than FISTA, which becomes a reference to decide which algorithm to use in practice according the noise level in the seismic data. The seislet transform based CS approach can achieve obviously better data recovery results than f - k transform based scenarios, considering both signal-to-noise ratio (SNR), local similarity comparison, and visual observation, because of a much sparser structure in the seislet transform domain. We have used both synthetic and field data examples to demonstrate the superior performance of the proposed seislet-based FPOCS approach.
Detection of weak target for MIMO radar based on Hough transform
Institute of Scientific and Technical Information of China (English)
Zeng Jiankui; He Zishu
2009-01-01
An effective method of multiple input multiple output (MIMO) radar weak target detection is proposed based on the Hough transform. The detection time duration is divided into multiple coherent processing intervals (CPIs). Within each CPI, conventional methods such as fast Fourier transform (FFT) is exploit to coherent inte-grating in same range cell. Furthermore, noncoherent integration through several range cells can be implemented by Hough transform among all CPIs. Thus, higher integration gain can be obtained. Simulation results are also given to demonstrate that the detection performance of weak moving target can be dramatically improved.
Institute of Scientific and Technical Information of China (English)
无
2001-01-01
Wavelet transform is used to analyze the scaling rule convection flow from two aspects. By utilizing the method of extended self similarity (ESS), one can find the obtained scaling exponent agrees well with the one obtained from the temperature data in a experiment of wind tunnel. And then we propose a newly defined formula based on wavelet transform, and can determine the scaling exponent ξ(q) of temperature data. The obtained results demonstrate that we can correctly extract ξ(q) by using the method which is named as wavelet transform maximum modulus (WTMM).``
Controlled Interphase Power Controller (IPC on the Base of Squashed Transformer
Directory of Open Access Journals (Sweden)
AMBROS, T.
2007-11-01
Full Text Available One of the perspective technical decisions in the field of management of modes of the electrical networks and systems are the Flexible Alternating Power Transmission Systems (FACTS or Power Controllers. Most perspective of them is Interphase Power Controller (IPC on the base of non-controllable phase-shifting transformer with the three working windings connected in 'delta' and constant shifting angle of 600. The analyses of its characteristics and working modes which are done in this paper are shone, then using multi-windings controllable transformer allows essentially to damage the required power of the phase-shifting transformer.
Energy Technology Data Exchange (ETDEWEB)
Hsieh, Cheng-Tao [Department of Electrical Engineering, Kun Shan University, Tainan 70101 (China); Lin, Jeu-Min [Department of Electrical Engineering, Far Eat University, Tainan 70101 (China); Huang, Shyh-Jier [Department of Electrical Engineering, National Cheng Kung University, Tainan 70101 (China)
2008-12-15
In this paper, a wavelet transform-based approach is proposed to detect the occurrence of islanding events in distributed generation systems. Thanks to time-frequency localization capabilities exhibited by wavelet transform, the approach embedded with this transform technique has grasped the appearance of the islanding event in a highly effective manner. Moreover, for those regions which are in need of a better visualization, the proposed approach would serve as an efficient aid such that the mains power disconnection can be better distinguished. To validate the feasibility of this approach, the method has been validated through several scenarios. Test results supported the effectiveness of the method for the application considered. (author)
Inverse log polar transformation algorithm based on sub-pixel interpolation
Institute of Scientific and Technical Information of China (English)
WANG Qi; LI Yan-jun; ZHANG Ke; XIONG Xian-ze
2006-01-01
Log polar transformation is an important algorithm of space-variant vision theory.It well depicts the retino-cortical mapping.Due to the logarithmic and the arctangent operation in the transformation,the log polar coordinate of an image is mostly a decimal fraction and the range is quite narrow.Aiming at solving these problems,this paper puts forward an inverse log polar transformation based on sub-pixel interpolation.The acquired log polar image of the new algorithm has no mosaic phenomenon,meanwhile it is a better simulation of retina-cortical mapping.
Study on Calibration System for Electronic Transformers Based on High-Accuracy PCI Card
Directory of Open Access Journals (Sweden)
Mingzhu Zhang
2013-03-01
Full Text Available With preliminary applying of Electronic Transformer (ET based on IEC 61850 standards in power grid, the calibrations of tested transformers have attracted extensive research attention. This study proposes a novel Calibration System of ET (CSET based on high-accuracy card. Data acquisition of ET and Standard Trans-former (ST is gotten by optic Ethernet and PCI-4462 data acquisition card, respectively. Meanwhile, the synchronized sampling between ET and ST is completed on the optic/electronic pulse signal of PCI synchronization card. The signals processing and human interface are realized by Labview software. The system proposed in the study is feasible for calibrating Electronic Voltage/Current Transformers (EVT/ECT of different voltage classes. System tests show that the precision of the system can get to 0.2°.
Study on Calibration System for Electronic Transformers Based on High-Accuracy PCI Card
Directory of Open Access Journals (Sweden)
Mingzhu Zhang
2013-05-01
Full Text Available With preliminary applying of Electronic Transformer (ET based on IEC 61850 standards in power grid, the calibration of tested transformers has attracted extensive research attention. This study proposes a novel Calibration System of ET (CSET based on high-accuracy card. Data acquisition of ET and standard trans-former (ST is gotten by optic Ethernet and PCI-4462 data acquisition card, respectively. Meanwhile, the synchronized sampling between ET and ST is completed on the optic/electronic pulse signal of PCI synchronization card. The signals processing and human interface are realized by Lab view software. The system proposed in the study is feasible for calibrating Electronic Voltage/Current Transformers (EVT/ECT of different voltage classes. System tests show that the precision of the system can get to 0.2°.
A sensor node lossless compression algorithm for non-slowly varying data based on DMD transform
Ren, Xuejun; Liu, Jianping
2013-03-01
Efficient utilization of energy is a core area of research in wireless sensor networks. Data compression methods to reduce the number of bits to be transmitted by the communication module will significantly reduce the energy requirement and increase the lifetime of the sensor node. Based on the lifting scheme 2-point discrete cosine transform (DCT), this paper proposed a new reversible recursive algorithm named Difference-Median-Difference (DMD) transform for lossless data compression in sensor node. The DMD transform can significantly reduce the spatio-temporal correlations among sensor data and can smoothly run in resource limited sensor nodes. Through an entropy encoder, the results of DMD transform can be compressed more compactly based on their statistical characteristics to achieve compression. Compared with the typical lossless algorithms, the proposed algorithm indicated better compression ratios than others for non-slowly-varying data, despite a less computational effort.
Rejection of Linear FM Interference in DSSS System Based on Fractional Fourier Transform
Institute of Scientific and Technical Information of China (English)
QI Lin; TAO Ran; ZHOU Si-yong
2005-01-01
A new method for the rejection of linear frequency modulation (LFM) interference in direct sequence spread spectrum (DSSS) system based on the fractional Fourier transform is proposed, and the configuration of the receiver with an interference exciser is also presented. Based on the property that the fractional Fourier transform of a signal is equivalent to rotating the signal in the time-frequency plane, the received signal is transform into a certain fractional Fourier domain, this transform will result in the least spectrum overlap between the signal and interference. Then, a narrowband filter is exploited to extract most of the interference energy. The performance analyses show that remarkable improvements in signal-to-noise ratio (SNR) and biterror-ratio (BER) are obtained.
Some Advances in Transformation-Based Part of Speech Tagging
Brill, E
1994-01-01
Most recent research in trainable part of speech taggers has explored stochastic tagging. While these taggers obtain high accuracy, linguistic information is captured indirectly, typically in tens of thousands of lexical and contextual probabilities. In [Brill92], a trainable rule-based tagger was described that obtained performance comparable to that of stochastic taggers, but captured relevant linguistic information in a small number of simple non-stochastic rules. In this paper, we describe a number of extensions to this rule-based tagger. First, we describe a method for expressing lexical relations in tagging that are not captured by stochastic taggers. Next, we show a rule-based approach to tagging unknown words. Finally, we show how the tagger can be extended into a k-best tagger, where multiple tags can be assigned to words in some cases of uncertainty.
Image Compression Using Wavelet Transform Based on the Lifting Scheme and its Implementation
Directory of Open Access Journals (Sweden)
A Alice Blessie
2011-05-01
Full Text Available This paper presents image compression using 9/7 wavelet transform based on the lifting scheme. This is simulated using ISE simulator and implemented in FPGA. The 9/7 wavelet transform performs well for the low frequency components. Implementation in FPGA is since because of its partial reconfiguration. The project mainly aims at retrieving the smooth images without any loss. This design may be used for both lossy and lossless compression.
Remote sensing image compression method based on lift scheme wavelet transform
Tao, Hongjiu; Tang, Xinjian; Liu, Jian; Tian, Jinwen
2003-06-01
Based on lifting scheme and the construction theorem of the integer Haar wavelet and biorthogonal wavelet, we propose a new integer wavelet transform construct method on the basis of lift scheme after introduciton of constructing specific-demand biorthogonal wavelet transform using Harr wavelet and Lazy wavelet. In this paper, we represent the method and algorithm of the lifting scheme, and we also give mathematical formulation on this method and experimental results as well.
DEFF Research Database (Denmark)
Arana Aristi, Iván; Holbøll, Joachim; Nielsen, Arne Hejde
2009-01-01
This paper presents the analysis of online time-domain measurements on the primary and secondary side of a wind turbine transformer in an Offshore Wind Farm (OWF), during one switching operation realized in the collection grid. The frequency characteristics up to 10 kHz of the current and voltage...... signals of each phase were compared and the transformers admittance characteristic was estimated based on these measurements. Based on the results from the previous analysis, it was decided to acquire a Sweep Frequency Response Analyzer (SFRA) to realize detailed transformer measurements. First...... the results from the measurements in a small dry-type transformer under laboratory conditions are presented, and finally the results from a large transformer measured in a in an industrial setting are shown....
Example-Based Sequence Diagrams to Colored Petri Nets Transformation Using Heuristic Search
Kessentini, Marouane; Bouchoucha, Arbi; Sahraoui, Houari; Boukadoum, Mounir
Dynamic UML models like sequence diagrams (SD) lack sufficient formal semantics, making it difficult to build automated tools for their analysis, simulation and validation. A common approach to circumvent the problem is to map these models to more formal representations. In this context, many works propose a rule-based approach to automatically translate SD into colored Petri nets (CPN). However, finding the rules for such SD-to-CPN transformations may be difficult, as the transformation rules are sometimes difficult to define and the produced CPN may be subject to state explosion. We propose a solution that starts from the hypothesis that examples of good transformation traces of SD-to-CPN can be useful to generate the target model. To this end, we describe an automated SD-to-CPN transformation method which finds the combination of transformation fragments that best covers the SD model, using heuristic search in a base of examples. To achieve our goal, we combine two algorithms for global and local search, namely Particle Swarm Optimization (PSO) and Simulated Annealing (SA). Our empirical results show that the new approach allows deriving the sought CPNs with at least equal performance, in terms of size and correctness, to that obtained by a transformation rule-based tool.
Liu, Bailing; Zhang, Fumin; Qu, Xinghua; Shi, Xiaojia
2016-02-18
Coordinate transformation plays an indispensable role in industrial measurements, including photogrammetry, geodesy, laser 3-D measurement and robotics. The widely applied methods of coordinate transformation are generally based on solving the equations of point clouds. Despite the high accuracy, this might result in no solution due to the use of ill conditioned matrices. In this paper, a novel coordinate transformation method is proposed, not based on the equation solution but based on the geometric transformation. We construct characteristic lines to represent the coordinate systems. According to the space geometry relation, the characteristic line scan is made to coincide by a series of rotations and translations. The transformation matrix can be obtained using matrix transformation theory. Experiments are designed to compare the proposed method with other methods. The results show that the proposed method has the same high accuracy, but the operation is more convenient and flexible. A multi-sensor combined measurement system is also presented to improve the position accuracy of a robot with the calibration of the robot kinematic parameters. Experimental verification shows that the position accuracy of robot manipulator is improved by 45.8% with the proposed method and robot calibration.
Directory of Open Access Journals (Sweden)
Bailing Liu
2016-02-01
Full Text Available Coordinate transformation plays an indispensable role in industrial measurements, including photogrammetry, geodesy, laser 3-D measurement and robotics. The widely applied methods of coordinate transformation are generally based on solving the equations of point clouds. Despite the high accuracy, this might result in no solution due to the use of ill conditioned matrices. In this paper, a novel coordinate transformation method is proposed, not based on the equation solution but based on the geometric transformation. We construct characteristic lines to represent the coordinate systems. According to the space geometry relation, the characteristic line scan is made to coincide by a series of rotations and translations. The transformation matrix can be obtained using matrix transformation theory. Experiments are designed to compare the proposed method with other methods. The results show that the proposed method has the same high accuracy, but the operation is more convenient and flexible. A multi-sensor combined measurement system is also presented to improve the position accuracy of a robot with the calibration of the robot kinematic parameters. Experimental verification shows that the position accuracy of robot manipulator is improved by 45.8% with the proposed method and robot calibration.
Steganography based on wavelet transform and modulus function
Institute of Scientific and Technical Information of China (English)
无
2007-01-01
In order to provide larger capacity of the hidden secret data while maintaining a good visual quality of stego-image,in accordance with the visual property that human eyes are less sensitive to strong texture,a novel steganographic method based on wavelet and modulus function is presented.First,an image is divided into blocks of prescribed size,and every block is decomposed into one-level wavelet.Then,the capacity of the hidden secret data is decided with the number of wavelet coefficients of larger magnitude.Finall,secret information is embedded by steganography based on modulus function. From the experimental results,the proposed method hides much more information and maintains a good visual quality of stego-image.Besides,the embedded data can be extracted from the stego-image without referencing the original image.
Institute of Scientific and Technical Information of China (English)
严辉容; 李兴慧; 覃才友
2015-01-01
基于重排Gabor变换和Radon变换理论，提出了基于重排Gabor变换和Radon变换的故障诊断技术。文章首先利用重排Gabor变换时频聚集性特点，对含噪信号进行重排Gabor变换，再将Gabor展开系数进行Radon变换，在Radon变换平面上提取像点，再进行Radon逆变换，实现信号降噪。仿真结果表明，该方法有效地抑制了噪声的干扰，成功地提取了故障特征信号。%According to the reassignment Gabor transform and Radon transform, and a feature extraction method based on the reassignment Gabor transform and Radon transform is proposed. Firstly, the reassign-ment Gabor transform is applied to the noise signal on the basis of its characteristics, and the Gabor coeffi-cients Gabor transform are processed by the Radon transform, and the image point in Radon transform plane is selected, Then the de-noised Gabor coefficients could be obtained by the Radon inverse transform. The simulated results indicate that this method can effectively reduce the noise interference, and the fault features are extracted successfully for mechanical diagnosis.
Stable Agrobacterium-Mediated Transformation of Maritime Pine Based on Kanamycin Selection
Directory of Open Access Journals (Sweden)
José M. Alvarez
2013-01-01
Full Text Available An efficient transformation protocol based on kanamycin selection was developed for Agrobacterium-mediated transformation of maritime pine embryonal masses. The binary vector pBINUbiGUSint, which contained neomycin phosphotransferase II (nptII as a selectable marker gene and β-glucuronidase (uidA as a reporter gene, was used for transformation studies. Different factors, such as embryogenic line, bacterial strain, bacterial concentration, and coculture duration, were examined and optimized. For selection of transformants, 15 mgL−1 kanamycin was used. The highest transformation efficiency (11.4 events per gram of fresh mass was achieved when a vigorously growing embryonal mass (embryogenic line L01 was cocultivated with Agrobacterium strain AGL1 at the optical density (OD600 nm of 0.3 for 72 h. Evidence of the stable transgene integration was obtained by polymerase chain reaction for the nptII and uidA genes and expression of the uidA gene. Maturation capacity of the transgenic lines was negatively affected by the transformation process. Induction of axillary shoots by preculturing the embryos with benzyladenine allowed overcoming the low maturation rates of some transformed lines. The transgenic embryos were germinated and the axillar shoots were rooted. Transgenic plants were transferred to potting substrate showing normal growth.
Stable Agrobacterium-mediated transformation of maritime pine based on kanamycin selection.
Alvarez, José M; Ordás, Ricardo J
2013-01-01
An efficient transformation protocol based on kanamycin selection was developed for Agrobacterium-mediated transformation of maritime pine embryonal masses. The binary vector pBINUbiGUSint, which contained neomycin phosphotransferase II (nptII) as a selectable marker gene and β -glucuronidase (uidA) as a reporter gene, was used for transformation studies. Different factors, such as embryogenic line, bacterial strain, bacterial concentration, and coculture duration, were examined and optimized. For selection of transformants, 15 mgL(-1) kanamycin was used. The highest transformation efficiency (11.4 events per gram of fresh mass) was achieved when a vigorously growing embryonal mass (embryogenic line L01) was cocultivated with Agrobacterium strain AGL1 at the optical density (OD(600 nm)) of 0.3 for 72 h. Evidence of the stable transgene integration was obtained by polymerase chain reaction for the nptII and uidA genes and expression of the uidA gene. Maturation capacity of the transgenic lines was negatively affected by the transformation process. Induction of axillary shoots by preculturing the embryos with benzyladenine allowed overcoming the low maturation rates of some transformed lines. The transgenic embryos were germinated and the axillar shoots were rooted. Transgenic plants were transferred to potting substrate showing normal growth.
A new adaptive algorithm for image denoising based on curvelet transform
Chen, Musheng; Cai, Zhishan
2013-10-01
The purpose of this paper is to study a method of denoising images corrupted with additive white Gaussian noise. In this paper, the application of the time invariant discrete curvelet transform for noise reduction is considered. In curvelet transform, the frame elements are indexed by scale, orientation and location parameters. It is designed to represent edges and the singularities along curved paths more efficiently than the wavelet transform. Therefore, curvelet transform can get better results than wavelet method in image denoising. In general, image denoising imposes a compromise between noise reduction and preserving significant image details. To achieve a good performance in this respect, an efficient and adaptive image denoising method based on curvelet transform is presented in this paper. Firstly, the noisy image is decomposed into many levels to obtain different frequency sub-bands by curvelet transform. Secondly, efficient and adaptive threshold estimation based on generalized Gaussian distribution modeling of sub-band coefficients is used to remove the noisy coefficients. The choice of the threshold estimation is carried out by analyzing the standard deviation and threshold. Ultimately, invert the multi-scale decomposition to reconstruct the denoised image. Here, to prove the performance of the proposed method, the results are compared with other existent algorithms such as hard and soft threshold based on wavelet. The simulation results on several testing images indicate that the proposed method outperforms the other methods in peak signal to noise ratio and keeps better visual in edges information reservation as well. The results also suggest that curvelet transform can achieve a better performance than the wavelet transform in image denoising.
Transforming a hospital nursing research fellowship into an evidence-based practice fellowship.
Gattuso, Jami S; Hinds, Pamela S; Beaumont, Cynthia; Funk, Adam J; Green, Jo; Max, Anita; Russell, Philisa; Windsor, Kelley
2007-12-01
An established hospital-based nursing research fellowship program was transformed into an evidence-based practice fellowship despite its previous high satisfaction ratings from nursing leaders and nurse fellow participants. The faculty for the fellowship program determined that the long-term outcomes of the research program were insufficient in light of the hospital resources committed to the fellowship program. An evidence-based practice approach was then created in anticipation that greater short-term and more sustained longer-term benefits for the hospital would be realized. The transformation of the fellowship and the short-term outcomes are described.
Komorowski, Dariusz; Pietraszek, Stanislaw
2016-01-01
This paper presents the analysis of multi-channel electrogastrographic (EGG) signals using the continuous wavelet transform based on the fast Fourier transform (CWTFT). The EGG analysis was based on the determination of the several signal parameters such as dominant frequency (DF), dominant power (DP) and index of normogastria (NI). The use of continuous wavelet transform (CWT) allows for better visible localization of the frequency components in the analyzed signals, than commonly used short-time Fourier transform (STFT). Such an analysis is possible by means of a variable width window, which corresponds to the scale time of observation (analysis). Wavelet analysis allows using long time windows when we need more precise low-frequency information, and shorter when we need high frequency information. Since the classic CWT transform requires considerable computing power and time, especially while applying it to the analysis of long signals, the authors used the CWT analysis based on the fast Fourier transform (FFT). The CWT was obtained using properties of the circular convolution to improve the speed of calculation. This method allows to obtain results for relatively long records of EGG in a fairly short time, much faster than using the classical methods based on running spectrum analysis (RSA). In this study authors indicate the possibility of a parametric analysis of EGG signals using continuous wavelet transform which is the completely new solution. The results obtained with the described method are shown in the example of an analysis of four-channel EGG recordings, performed for a non-caloric meal.
Digital Image Watermarking Based on DiscreteWavelet Transform
Institute of Scientific and Technical Information of China (English)
丁玮; 闫伟齐; 齐东旭
2002-01-01
This paper aims at digital watermark which is a new popular research topic recently, presents some methods to embed digital watermark based on modifying frequency coefficients in discrete wavelettransfor(DWT)domain.First,thepresent progress of digital watermark is briefly introduced; after that, starting from Pitas's method and discarding hispseudo random number method, the authors use a digital image scrambling technology as preprocessing fordigital watermarking. Then the authors discuss how to embed a 1-bit digital image as watermark in frequency domain. Finallyanotherdigital watermarking method is given in which 3-D DWT is used to transformagivendigitalimage.Basedontheexperimentalresults, it is shown that the proposed methods are robust to a large extent.
Watermarking Scheme Based on Wavelet Transformation and Visual Cryptography
Institute of Scientific and Technical Information of China (English)
Young-Chang Hou; Shih-Chieh Wei; Hsin-Ju Liu; A-Yu Tseng
2014-01-01
Based on the principles of the visual cryptography and the law of large numbers, the unexpanded shares are generated during the processes of embedding and verifying the hidden watermark. The watermark embedding is done in the frequency domain, which can be decoded by the human visual system (HVS) without the necessity of any complicated computation and the help of the original image. Experimental results indicated that our method had a good robustness on darkening, lightening, blurring, sharpening, noise, distorting, jitter, joint photographic experts group (JPEG) compression, and crop attacks.
Multispectral and panchromatic image fusion based on unsubsampled contourlet transform
Liu, Hui; Yuan, Yan; Su, Lijuan; Hu, Liang; Zhang, Siyuan
2013-12-01
In order to achieve the high-resolution multispectral image, we proposed an algorithm for MS image and PAN image fusion based on NSCT and improved fusion rule. This method takes into account two aspects, the spectral similarity between fused image and the original MS image and enhancing the spatial resolution of the fused image. According to local spectral similarity between MS and PAN images, it can help to select high frequency detail coefficients from PAN image, which are injected into MS image then. Thus, spectral distortion is limited; the spatial resolution is enhanced. The experimental results demonstrate that the proposed fusion algorithm perform some improvements in integrating MS and PAN images.
Hilbert transform based analyses on ship-rocking signals
Huang, Wei; Kang, Deyong; Chen, Zhi
2015-01-01
The ship-rocking is a crucial factor which affects the accuracy of the ocean-based flight vehicle measurement. Here we have analyzed four groups of ship-rocking time series in horizontal and vertical directions utilizing a Hilbert based method from statistical physics. Our method gives a way to construct an analytic signal on the two-dimensional plane from a one-dimensional time series. The analytic signal share the complete property of the original time series. From the analytic signal of a time series, we have found some information of the original time series which are often hidden from the view of the conventional methods. The analytic signals of interest usually evolve very smoothly on the complex plane. In addition, the phase of the analytic signal is usually moves linearly in time. From the auto-correlation and cross-correlation functions of the original signals as well as the instantaneous amplitudes and phase increments of the analytic signals we have found that the ship-rocking in horizontal directi...
Aarons, Gregory A.
2006-01-01
Objective Leadership in organizations is important in shaping workers’ perceptions, responses to organizational change, and acceptance of innovations, such as evidence-based practices. Transformational leadership inspires and motivates followers, whereas transactional leadership is based more on reinforcement and exchanges. Studies have shown that in youth and family service organizations, mental health providers’ attitudes toward adopting an evidence-based practice are associated with organizational context and individual provider differences. The purpose of this study was to expand these findings by examining the association between leadership and mental health providers’ attitudes toward adopting evidence-based practice. Methods Participants were 303 public-sector mental health service clinicians and case managers from 49 programs who were providing mental health services to children, adolescents, and their families. Data were gathered on providers’ characteristics, attitudes toward evidence-based practices, and perceptions of their supervisors’ leadership behaviors. Zero-order correlations and multilevel regression analyses were conducted that controlled for effects of service providers’ characteristics. Results Both transformational and transactional leadership were positively associated with providers’ having more positive attitudes toward adoption of evidence-based practice, and transformational leadership was negatively associated with providers’ perception of difference between the providers’ current practice and evidence-based practice. Conclusions Mental health service organizations may benefit from improving transformational and transactional supervisory leadership skills in preparation for implementing evidence-based practices. PMID:16870968
Using Arts-Based Activities to Foster Transformative Learning during a Teaching Practicum in Kenya
Black, Glenda; Bernardes, Rogerio
2012-01-01
This essay explores and presents strategies we, as Canadian faculty facilitators of a teaching practicum in Kenya, used to foster the pre-service teachers' knowledge and understanding of critical reflection and transformative learning processes by using arts-based activities. Participation in the arts-based activities while in Kenya encouraged the…
Institute of Scientific and Technical Information of China (English)
Wang Na; Zhang Li; Zhou Xiao'an; Jia Chuanying; Li Xia
2005-01-01
This letter exploits fundamental characteristics of a wavelet transform image to form a progressive octave-based spatial resolution. Each wavelet subband is coded based on zeroblock and quardtree partitioning ordering scheme with memory optimization technique. The method proposed in this letter is of low complexity and efficient for Internet plug-in software.
A Transformation-oriented Methodology to Knowledge-based Conceptual Data Warehouse Design
Directory of Open Access Journals (Sweden)
Opim S. Sitompul
2006-01-01
Full Text Available Applications of artificial intelligence (AI technology in the form of knowledge-based systems within the context of database design have been extensively researched particularly to provide support within the conceptual design phase. However, a similar approach to the task of data warehouse design has yet to be seriously initiated. In this paper, we proposed a design methodology for conceptual data warehouse design called the transformation-oriented methodology, which transforms an Entity-Relationship (ER model into a multidimensional model based on a series of transformation and analysis rules. The transformation-oriented methodology translates the ER model into a specification language model and transformed it into an initial problem domain model. A set of synthesis and diagnosis rules will then gradually transform the problem domain model into the multidimensional model. A prototype KB tool called the DWDesigner has been developed to implement the aforementioned methodology. The multidimensional model produces by the DWDesigner as output is presented in a graphical form for better visualization. Testing has been conducted to a number of design problems, such as university, business and hospital domains and consistent results have been achieved.
Directory of Open Access Journals (Sweden)
Wei Liu
2016-01-01
Full Text Available The difference of factor input structure determines different response to environmental regulation. This paper constructs a theoretical model including environmental regulation, factor input structure, and industrial transformation and conducts a policy simulation based on the difference of influencing mechanism of environmental regulation considering industrial heterogeneity. The findings show that the impact of environmental regulation on industrial transformation presents comparison of distortion effect of resource allocation and technology effect. Environmental regulation will promote industrial transformation when technology effect of environmental regulation is stronger than distortion effect of resource allocation. Particularly, command-control environmental regulation has a significant incentive effect and spillover effect of technological innovation on cleaning industries, but these effects do not exist in pollution-intensive industries. Command-control environmental regulation promotes industrial transformation. The result of simulation showed that environmental regulation of market incentives is similar to that of command-control.
Directory of Open Access Journals (Sweden)
Byambaa Dorj
2016-01-01
Full Text Available The next promising key issue of the automobile development is a self-driving technique. One of the challenges for intelligent self-driving includes a lane-detecting and lane-keeping capability for advanced driver assistance systems. This paper introduces an efficient and lane detection method designed based on top view image transformation that converts an image from a front view to a top view space. After the top view image transformation, a Hough transformation technique is integrated by using a parabolic model of a curved lane in order to estimate a parametric model of the lane in the top view space. The parameters of the parabolic model are estimated by utilizing a least-square approach. The experimental results show that the newly proposed lane detection method with the top view transformation is very effective in estimating a sharp and curved lane leading to a precise self-driving capability.
[The noise filtering and baseline correction for harmonic spectrum based on wavelet transform].
Guo, Yuan; Zhao, Xue-Hong; Zhang, Rui; Hu, Ya-Jun; Wang, Yan
2013-08-01
The problem of noise and baseline drift is a hot topic in infrared spectral harmonic detection system. This paper presents a new algorithm based on wavelet transform Mallet decomposition to solve the problem of eliminating a variety of complex noise and baseline drift in the harmonic detection. In the algorithm, the appropriate wavelet function and decomposition level were selected to decomposed the noise, baseline drift and useful signal in the harmonic curve into different frequency bands. the bands' information was analysed and a detecting band was set, then the information in useful frequency was reserved by zeroing method of treatment and the coefficient of the threshold. We can just use once transform and reconstruction to remove interference noise and baseline from double-harmonic signal by applying the wavelet transform technique to the harmonic detection spectrum pretreatment. Experiments show that the wavelet transform method can be used to different harmonic detection systems and has universal applicability.
A depth estimation method based on geometric transformation for stereo light microscope.
Fan, Shengli; Yu, Mei; Wang, Yigang; Jiang, Gangyi
2014-01-01
Stereo light microscopes (SLM) with narrow vision and shallow depth of field are widely used in micro-domain research. In this paper, we propose a depth estimation method of micro objects based on geometric transformation. By analyzing the optical imaging geometry, the definition of geometric transformation distance is given and the depth-distance relation express is obtained. The parameters of geometric transformation and express are calibrated with calibration board images captured in aid of precise motorized stage. The depth of micro object can be estimated by calculating the geometric transformation distance. The proposed depth-distance relation express is verified using an experiment in which the depth map of an Olanzapine tablet surface is reconstructed.
Institute of Scientific and Technical Information of China (English)
无
2002-01-01
Based on pair potential, the Bragg Williams (B-W) model is modified to take into account the effect of the lattice parameter on theoretical order-disorder transformation analysis. The main purpose of this work is to understand the basic aspects of this effect and related reasonable model on order-disorder transformation. In the present approach, the configuration free energy is chosen as function of the lattice parameter and the long-range order. This energy is calculated through Taylor's expansion, starting from the disordered state. It was found that the configuration free energy has been strongly modified when the lattice parameter is taken into account. It was also found only one type of order-disorder transformation exists in AB alloy and three kinds of order-disorder transformations for non-equiatomic alloy system such as A3B alloy. This result is in agreement with experiments.
Mine-hoist fault-condition detection based on the wavelet packet transform and kernel PCA
Institute of Scientific and Technical Information of China (English)
XIA Shi-xiong; NIU Qiang; ZHOU Yong; ZHANG Lei
2008-01-01
A new algorithm was developed to correctly identify fault conditions and accurately monitor fault development in a mine hoist. The new method is based on the Wavelet Packet Transform (WPT) and kernel PCA (Kernel Principal Component Analysis, KPCA). For non-linear monitoring systems the key to fault detection is the extracting of main features. The wavelet packet transform is a novel technique of signal processing that possesses excellent characteristics of time-frequency localization. It is suitable for analysing time-varying or transient signals. KPCA maps the original input features into a higher dimension feature space through a non-linear mapping. The principal components are then found in the higher dimension feature space. The KPCA transformation was applied to extracting the main nonlinear features from experimental fault feature data after wavelet packet transformation. The results show that the proposed method affords credible fault detection and identification.
Palao, J P; Palao, Jose P.; Kosloff, Ronnie
2002-01-01
A quantum gate is realized by specific unitary transformations operating on states representing qubits. Considering a quantum system employed as an element in a quantum computing scheme, the task is therefore to enforce the pre-specified unitary transformation. This task is carried out by an external time dependent field. Optimal control theory has been suggested as a method to compute the external field which alters the evolution of the system such that it performs the desire unitary transformation. This study compares two recent implementations of optimal control theory to find the field that induces a quantum gate. The first approach is based on the equation of motion of the unitary transformation. The second approach generalizes the state to state formulation of optimal control theory. This work highlight the formal relation between the two approaches.
Landau theory of martensitic transformation in Fe-Mn-Si based alloys
Institute of Scientific and Technical Information of China (English)
无
2002-01-01
Considering the features of martensitic transformation in Fe-Mn-Si based alloys, the Landau theory is established by introducing the density of stacking faults as a new order parameter ηand the corresponding free energy function. By using such an order parameter, the stacking fault mechanism of the nucleation and growth for the γ(fcc)→ε(hcp) martensitic transformation can be reasonably explained, and a further detailed mechanism is proposed. The stacking faults are generated and overlapped in an irregular form at the beginning and then becoming regular to create some transition structures till a stable phase forms at a certain temperature. The importance of the interface soliton is to complete the transformations into various structures of martensite but not the twinned one. The thermodynamics of fcc→hcp transformation and those between different transition structures are described by the free energy function established in the present note.
Hu, Yiqun; Xie, Xinwen; Liu, Xingbin; Zhou, Nanrun
2017-07-01
A novel quantum multi-image encryption algorithm based on iteration Arnold transform with parameters and image correlation decomposition is proposed, and a quantum realization of the iteration Arnold transform with parameters is designed. The corresponding low frequency images are obtained by performing 2-D discrete wavelet transform on each image respectively, and then the corresponding low frequency images are spliced randomly to one image. The new image is scrambled by the iteration Arnold transform with parameters, and the gray-level information of the scrambled image is encoded by quantum image correlation decomposition. For the encryption algorithm, the keys are iterative times, added parameters, classical binary and orthonormal basis states. The key space, the security and the computational complexity are analyzed, and all of the analyses show that the proposed encryption algorithm could encrypt multiple images simultaneously with lower computational complexity compared with its classical counterparts.
Quantum image encryption based on generalized affine transform and logistic map
Liang, Hao-Ran; Tao, Xiang-Yang; Zhou, Nan-Run
2016-07-01
Quantum circuits of the generalized affine transform are devised based on the novel enhanced quantum representation of digital images. A novel quantum image encryption algorithm combining the generalized affine transform with logistic map is suggested. The gray-level information of the quantum image is encrypted by the XOR operation with a key generator controlled by the logistic map, while the position information of the quantum image is encoded by the generalized affine transform. The encryption keys include the independent control parameters used in the generalized affine transform and the logistic map. Thus, the key space is large enough to frustrate the possible brute-force attack. Numerical simulations and analyses indicate that the proposed algorithm is realizable, robust and has a better performance than its classical counterpart in terms of computational complexity.
Fourier transform profilometry based on mean envelope extraction
Zhang, Xiaoxuan; Huang, Shujun; Gao, Nan; Zhang, Zonghua
2017-02-01
Based on an image pre-processing algorithm, a three-dimensional (3D) object measurement method is proposed by combining time domain and frequency domain analysis. Firstly, extreme points of sinusoidal fringes under the disturbance of noise are accurately extracted. Secondly, mean envelope of the fringe is obtained through appropriate interpolation method and then removed. Thirdly, phase information is extracted by using specific filtering in Fourier spectrum of the pre-processed fringe pattern. Finally, simulated and experimental results show a good property of the proposed method in accuracy and measurement range. The proposed method can achieve 3D shape of objects having large slopes and/or discontinuous surfaces from one-shot acquisition by using color fringe projection technique and will have wide applications in the fields of fast measurement.
Diffusion filtering in image processing based on wavelet transform
Institute of Scientific and Technical Information of China (English)
LIU Feng
2006-01-01
The nonlinear diffusion filtering in image processing bases on the heat diffusion equations. Its key is the control of diffusion amount. In the previous models, the diffusivity depends on the gradients of images. So it is easily affected by noises. This paper first gives a new multiscale computational technique for diffusivity. Then we proposed a class of nonlinear wavelet diffusion (NWD) models that are used to restore images. The NWD model has strong ability to resist noise.But it, like the previous models, requires higher computational effort. Thus, by simplifying the NWD, we establish linear wavelet diffusion (LWD) models that consist of advection and diffusion. Since there exists the advection, the LWD filter is anisotropic, and hence can well preserve edges although the diffusion at edges is isotropic. The advantage is that the LWD model is easy to be analyzed and has lesser computational load. Finally, a variety of numerical experiments compared with the previous model are shown.
Place-based education: a transformative activist stance
Coughlin, Christine A.; Kirch, Susan A.
2010-12-01
The ethnography presented by van Eijck and Roth focuses on the activities of people involved in a government funded internship program in conservation and restoration, which was offered by a `multidisciplinary research center' through a local First Nation adult education center. The internship was designed, in partnership with a local non-profit conservation society (OceanHealth), to appeal to First Nation men and women considering career change, returning to school, or re-entering the work place. The primary aim of the internship was to `provide authentic science for diverse student populations (and their teachers), with particular attention to the needs of students from First Nations, to become scientifically literate to the extent that it prepares them for participating in public debates, community decision-making, and personal living consistent with long-term environmentally sustainable forms of life'. The authors report that at least one of the two interns was not interested in science and a WSÁNEC elder expressed dissatisfaction with the efforts to establish the nature park and its current approved uses. Van Eijck and Roth argue that the divergence between the project aims and the goals of the participants are a result of how `place' is viewed in place-based education and that disagreements like these can be resolved if place is theorized as chronotope. There are many interesting ideas raised and directions taken in the article by van Eijck and Roth. After several discussions during the review process, we decided to focus our forum response on the meaning of `place' in place-based education, the utility of theorizing place as a chronotope, the implications for teaching-learning (`education'), and musings on what remains unclear.
Wang, Lei; Yang, Shuaisai; Tang, Zhixiang; Shu, Weixing
2016-10-01
We propose a three-dimensional (3D) phase transformation method by an impedance-matched dielectric slab and apply it to generating hollow beams. We first employ transformation optics to establish a method for the transformation between two arbitrary 3D wavefronts through a flat dielectric and impedance-matched material. Then the method is used to convert a solid beam into a hollow beam with desired wavefront. By tuning the transformation surface, different hollow beams can be produced. The results are further validated by 3D finite-difference time-domain simulations.
Mechanism of Process-Induced Salt-to-Free Base Transformation of Pharmaceutical Products
DEFF Research Database (Denmark)
Bruun Hansen, Thomas; Qu, Haiyan
2014-01-01
pH-solubility profiles of a model drug in salt form was established and the mechanism of salt-to-free base form transformation was investigated by increasing pH of the system. Wet massing experiments along with suspension experiments were used to investigate the effects of excipients on the stabi......pH-solubility profiles of a model drug in salt form was established and the mechanism of salt-to-free base form transformation was investigated by increasing pH of the system. Wet massing experiments along with suspension experiments were used to investigate the effects of excipients...... on the stability of the salt form. It was found that nucleation of the free base did not occur at pHmax but that instead, a new boundary, the pHmetastable had to be reached before transformation occurred. It was also shown that some excipients impact the stability of the drug, this can help find excipients...
Grid-Based Fourier Transform Phase Contrast Imaging
Tahir, Sajjad
Low contrast in x-ray attenuation imaging between different materials of low electron density is a limitation of traditional x-ray radiography. Phase contrast imaging offers the potential to improve the contrast between such materials, but due to the requirements on the spatial coherence of the x-ray beam, practical implementation of such systems with tabletop (i.e. non-synchrotron) sources has been limited. One recently developed phase imaging technique employs multiple fine-pitched gratings. However, the strict manufacturing tolerances and precise alignment requirements have limited the widespread adoption of grating-based techniques. In this work, we have investigated a technique recently demonstrated by Bennett et al. that utilizes a single grid of much coarser pitch. Our system consisted of a low power 100 microm spot Mo source, a CCD with 22 microm pixel pitch, and either a focused mammography linear grid or a stainless steel woven mesh. Phase is extracted from a single image by windowing and comparing data localized about harmonics of the grid in the Fourier domain. A Matlab code was written to perform the image processing. For the first time, the effects on the diffraction phase contrast and scattering amplitude images of varying grid types and periods, and of varying the window function type used to separate the harmonics, and the window widths, were investigated. Using the wire mesh, derivatives of the phase along two orthogonal directions were obtained and new methods investigated to form improved phase contrast images.
Mesh-based phase contrast Fourier transform imaging
Tahir, Sajjad; Bashir, Sajid; MacDonald, C. A.; Petruccelli, Jonathan C.
2017-04-01
Traditional x-ray radiography is limited by low attenuation contrast in materials of low electron density. Phase contrast imaging offers the potential to improve the contrast between such materials, but due to the requirements on the spatial coherence of the x-ray beam, practical implementation of such systems with tabletop (i.e. non-synchrotron) sources has been limited. One phase imaging technique employs multiple fine-pitched gratings. However, the strict manufacturing tolerances and precise alignment requirements have limited the widespread adoption of grating-based techniques. In this work, we have investigated a recently developed technique that utilizes a single grid of much coarser pitch. Our system consisted of a low power 100 μm spot Mo source, a CCD with 22 μm pixel pitch, and either a focused mammography linear grid or a stainless steel woven mesh. Phase is extracted from a single image by windowing and comparing data localized about harmonics of the mesh in the Fourier domain. The effects on the diffraction phase contrast and scattering amplitude images of varying grid types and periods, and of varying the width of the window function used to separate the harmonics were investigated. Using the wire mesh, derivatives of the phase along two orthogonal directions were obtained and combined to form improved phase contrast images.
Haux, Reinhold; Kuballa, Stefanie; Schulze, Mareike; Böhm, Claudia; Gefeller, Olaf; Haaf, Jan; Henning, Peter; Mielke, Corinna; Niggemann, Florian; Schürg, Andrea; Bergemann, Dieter
2016-12-07
Based on today's information and communication technologies the open access paradigm has become an important approach for adequately communicating new scientific knowledge. Summarizing the present situation for journal transformation. Presenting criteria for adequate transformation as well as a specific approach for it. Describing our exemplary implementation of such a journal transformation. Studying the respective literature as well as discussing this topic in various discussion groups and meetings (primarily of editors and publishers, but also of authors and readers), with long term experience as editors and /or publishers of scientific publications as prerequisite. There is a clear will, particularly of political and funding organizations, towards open access publishing. In spite of this, there is still a large amount of scientific knowledge, being communicated through subscription-based journals. For successfully transforming such journals into open access, sixteen criteria for a goal-oriented, stepwise, sustainable, and fair transformation are suggested. The Tandem Model as transformation approach is introduced. Our exemplary implementation is done in the Trans-O-MIM project. It is exploring strategies, models and evaluation metrics for journal transformation. As instance the journal Methods of Information in Medicine will apply the Tandem Model from 2017 onwards. Within Trans-O-MIM we will reach at least nine of the sixteen criteria for adequate transformation. It was positive to implement Trans-O-MIM as international research project. After first steps for transforming Methods have successfully been made, challenges will remain, among others, in identifying appropriate incentives for open access publishing in order to support its transformation.
Shi, J.; Turteltaub, S.; Van der Giessen, E.
2010-01-01
There is much interest recently in the possibility of combining two strengthening effects, namely the reduction of grain size (Hall-Fetch effect) and the transformation-induced plasticity effect (strengthening due to a martensitic transformation). The present work is concerned with the analysis of t
Empiric analysis of zero voltage switching in piezoelectric transformer based resonant converters
DEFF Research Database (Denmark)
Rødgaard, Martin Schøler; Andersen, Thomas; Andersen, Michael A. E.
2012-01-01
Research and development within piezoelectric transformer (PT) based converters are rapidly increasing, as the technology is maturing and starts to prove its capabilities. High power density and high efficiencies are reported and recently several inductor-less converters have emerged [1][2][7][10......Research and development within piezoelectric transformer (PT) based converters are rapidly increasing, as the technology is maturing and starts to prove its capabilities. High power density and high efficiencies are reported and recently several inductor-less converters have emerged [1...
[Detection of R-wave in Fetal EGG Based on Wavelet Transform and Matched Filtering].
Yan, Wenhong; Jiang, Ning
2015-09-01
By analyzing the characteristics of maternal abdominal ECG (Electrocardiogram), a method based on wavelet transform and matched filtering is proposed to detect the R-wave in fetal EGG (FECG). In this method, the high-frequency coefficients are calculated by using wavelet transform. First, the maternal QRS template is obtained by using the arithmetic mean scheme. Finally, the R-wave of FECG is detected based on matched filtering. The experimental results show that this method can effectively eliminate the noises, such as the maternal ECG signal and baseline drift, enhancing the accuracy of the detection of fetal ECG.
Classification of melanoma using wavelet-transform-based optimal feature set
Walvick, Ronn P.; Patel, Ketan; Patwardhan, Sachin V.; Dhawan, Atam P.
2004-05-01
The features used in the ABCD rule for characterization of skin lesions suggest that the spatial and frequency information in the nevi changes at various stages of melanoma development. To analyze these changes wavelet transform based features have been reported. The classification of melanoma using these features has produced varying results. In this work, all the reported wavelet transform based features are combined to form a single feature set. This feature set is then optimized by removing redundancies using principal component analysis. A feed forward neural network trained with the back propagation algorithm is then used in the classification process to obtain better classification results.
Zhang, Hongbo; Yi, Xingwen; Chen, Lei; Zhang, Jing; Deng, Mingliang; Qiu, Kun
2012-10-01
As an alternate to fast Fourier transform-based orthogonal frequency-division multiplexing (OFDM), wavelet packet transform (WPT)-based OFDM (WPT-OFDM) does not require cyclic prefix to avoid inter-symbol-interference. The wavelet has many varieties and therefore, it can provide more freedom for system design to suit different applications. We propose a real-valued WPT-OFDM that uses intensity modulation/direct detection. We also conduct an experiment to verify its performance through a 75-km standard single-mode fiber.
Determination of sulfur compounds in hydrotreated transformer base oil by potentiometric titration.
Chao, Qiu; Sheng, Han; Cheng, Xingguo; Ren, Tianhui
2005-06-01
A method was developed to analyze the distribution of sulfur compounds in model sulfur compounds by potentiometric titration, and applied to analyze hydrotreated transformer base oil. Model thioethers were oxidized to corresponding sulfoxides by tetrabutylammonium periodate and sodium metaperiodate, respectively, and the sulfoxides were titrated by perchloric acid titrant in acetic anhydride. The contents of aliphatic thioethers and total thioethers were then determined from that of sulfoxides in solution. The method was applied to determine the organic sulfur compounds in hydrotreated transformer base oil.
Directory of Open Access Journals (Sweden)
Manoj Tripathy
2012-01-01
Full Text Available This paper describes a new approach for power transformer differential protection which is based on the wave-shape recognition technique. An algorithm based on neural network principal component analysis (NNPCA with back-propagation learning is proposed for digital differential protection of power transformer. The principal component analysis is used to preprocess the data from power system in order to eliminate redundant information and enhance hidden pattern of differential current to discriminate between internal faults from inrush and overexcitation conditions. This algorithm has been developed by considering optimal number of neurons in hidden layer and optimal number of neurons at output layer. The proposed algorithm makes use of ratio of voltage to frequency and amplitude of differential current for transformer operating condition detection. This paper presents a comparative study of power transformer differential protection algorithms based on harmonic restraint method, NNPCA, feed forward back propagation neural network (FFBPNN, space vector analysis of the differential signal, and their time characteristic shapes in Park’s plane. The algorithms are compared as to their speed of response, computational burden, and the capability to distinguish between a magnetizing inrush and power transformer internal fault. The mathematical basis for each algorithm is briefly described. All the algorithms are evaluated using simulation performed with PSCAD/EMTDC and MATLAB.
3D printing optical watermark algorithms based on the combination of DWT and Fresnel transformation
Hu, Qi; Duan, Jin; Zhai, Di; Wang, LiNing
2016-10-01
With the continuous development of industrialization, 3D printing technology steps into individuals' lives gradually, however, the consequential security issue has become the urgent problem which is imminent. This paper proposes the 3D printing optical watermark algorithms based on the combination of DWT and Fresnel transformation and utilizes authorized key to restrict 3D model printing's permissions. Firstly, algorithms put 3D model into affine transform, and take the distance from the center of gravity to the vertex of 3D object in order to generate a one-dimensional discrete signal; then make this signal into wavelet transform and put the transformed coefficient into Fresnel transformation. Use math model to embed watermark information into it and finally generate 3D digital model with watermarking. This paper adopts VC++.NET and DIRECTX 9.0 SDK for combined developing and testing, and the results show that in fixed affine space, achieve the robustness in translation, revolving and proportion transforms of 3D model and better watermark-invisibility. The security and authorization of 3D model have been protected effectively.
Wavelet Based Hilbert Transform with Digital Design and Application to QCM-SS Watermarking
Directory of Open Access Journals (Sweden)
S. P. Maity
2008-04-01
Full Text Available In recent time, wavelet transforms are used extensively for efficient storage, transmission and representation of multimedia signals. Hilbert transform pairs of wavelets is the basic unit of many wavelet theories such as complex filter banks, complex wavelet and phaselet etc. Moreover, Hilbert transform finds various applications in communications and signal processing such as generation of single sideband (SSB modulation, quadrature carrier multiplexing (QCM and bandpass representation of a signal. Thus wavelet based discrete Hilbert transform design draws much attention of researchers for couple of years. This paper proposes an (i algorithm for generation of low computation cost Hilbert transform pairs of symmetric filter coefficients using biorthogonal wavelets, (ii approximation to its rational coefficients form for its efficient hardware realization and without much loss in signal representation, and finally (iii development of QCM-SS (spread spectrum image watermarking scheme for doubling the payload capacity. Simulation results show novelty of the proposed Hilbert transform design and its application to watermarking compared to existing algorithms.
A Fragile Watermarking Based on Legendre Transform for Color Images (Fwltci
Directory of Open Access Journals (Sweden)
S. K.Ghosal
2013-08-01
Full Text Available In this paper, a Legendre transformation (LT based fragile watermarking technique has been proposed forcolor image authentication. The authentication is done by inserting the watermark into the carrier imagesin transform domain. An initial pixel adjustment has been applied on each pixel component to keep thepixel value positive and less than or equal to the maximum. The Legendre transformation (LT is applied oneach pair of pixel components of the carrier image in row major order. The first transformed componentcan fabricate two bits whereas the second component fabricates three bits of authenticating watermarkstarting from the least significant bit position (LSB-0. A post adjustment is also applied to keep theembedded components closer to the original without affecting the least three significant bits. The inverseLegendre transform (ILT is applied on each adjusted pair to re-generate the watermarked image. Duringinverse transform, at if the second pixel component of the adjusted pair become fractional, then the LSB-2of the first component is set to one; otherwise is set to zero. The reverse procedure is applied at thedestination to retrieve back the watermark which in turn is verified for authentication through a messagedigest. Experimental results conform that the proposed algorithm has improvised the payload and PSNRover Varsaki et. al’s Method [6] and LTCIA technique [7].
Study on Matching a 300 MVA Motor Generator with an Ohmic Heating Power Supply in HL-2M
Peng, Jianfei; Xuan, Weimin; Wang, Haibing; Li, Huajun; Wang, Yingqiao; Wang, Shujin
2013-03-01
A new 300 MVA/1350 MJ motor generator (MG) will be built to feed all of the poloidal field power supplies (PFPS) and auxiliary heating power supplies of the HL-2M tokamak. The MG has a vertical-shaft salient pole 6-phase synchronous generator and a coaxial 8500 kW induction motor. The Ohmic heating power supply (OHPS) consisting of 4-quadrant DC pulsed convertor is the one with the highest parameters among the PFPS. Therefore, the match between the generator and the OHPS is very important. The matching study with Matlab/Simulink is described in this paper. The simulation results show that the subtransient reactance of the generator is closely related to the inversion operation of the OHPS. By setting various subtransient reactance in the simulation generator model and considering the cost reduction, the optimized parameters are obtained as x″d = 0.405 p.u. at 100 Hz for the generator. The models built in the simulation can be used as an important tool for studying the dynamic characteristics and the control strategy of other HL-2M PFPSes.
Decay heat power of spent nuclear fuel of power reactors with high burnup at long-term storage
Ternovykh, Mikhail; Tikhomirov, Georgy; Saldikov, Ivan; Gerasimov, Alexander
2017-09-01
Decay heat power of actinides and fission products from spent nuclear fuel of power VVER-1000 type reactors at long-term storage is calculated. Two modes of storage are considered: mode in which single portion of actinides or fission products is loaded in storage facility, and mode in which actinides or fission products from spent fuel of one VVER reactor are added every year in storage facility during 30 years and then accumulated nuclides are stored without addition new nuclides. Two values of fuel burnup 40 and 70 MW·d/kg are considered for the mode of storage of single fuel unloading. For the mode of accumulation of spent fuel with subsequent storage, one value of burnup of 70 MW·d/kg is considered. Very long time of storage 105 years accepted in calculations allows to simulate final geological disposal of radioactive wastes. Heat power of fission products decreases quickly after 50-100 years of storage. The power of actinides decreases very slow. In passing from 40 to 70 MW·d/kg, power of actinides increases due to accumulation of higher fraction of 244Cm. These data are important in the back end of fuel cycle when improved cooling system of the storage facility will be required along with stronger radiation protection during storage, transportation and processing.
Werdiningsih, Indah; Zaman, Badrus; Nuqoba, Barry
2017-08-01
This paper presents classification of brain cancer using wavelet transformation and Adaptive Neighborhood Based Modified Backpropagation (ANMBP). Three stages of the processes, namely features extraction, features reduction, and classification process. Wavelet transformation is used for feature extraction and ANMBP is used for classification process. The result of features extraction is feature vectors. Features reduction used 100 energy values per feature and 10 energy values per feature. Classifications of brain cancer are normal, alzheimer, glioma, and carcinoma. Based on simulation results, 10 energy values per feature can be used to classify brain cancer correctly. The correct classification rate of proposed system is 95 %. This research demonstrated that wavelet transformation can be used for features extraction and ANMBP can be used for classification of brain cancer.
Multi-level denoising and enhancement method based on wavelet transform for mine monitoring
Institute of Scientific and Technical Information of China (English)
Yanqin Zhao
2013-01-01
Based on low illumination and a large number of mixed noises contained in coal mine,denoising with one method usually cannot achieve good results,So a multi-level image denoising method based on wavelet correlation relevant inter-scale is presented.Firstly,we used directional median filter to effectively reduce impulse noise in the spatial domain,which is the main cause of noise in mine.Secondly,we used a Wiener filtration method to mainly reduce the Gaussian noise,and then finally used a multi-wavelet transform to minimize the remaining noise of low-light images in the transform domain.This multi-level image noise reduction method combines spatial and transform domain denoising to enhance benefits,and effectively reduce impulse noise and Gaussian noise in a coal mine,while retaining good detailed image characteristics of the underground for improving quality of images with mixing noise and effective low-light environment.
Electrical-Based Diagnostic Techniques for Assessing Insulation Condition in Aged Transformers
Directory of Open Access Journals (Sweden)
Issouf Fofana
2016-08-01
Full Text Available The condition of the internal cellulosic paper and oil insulation are of concern for the performance of power transformers. Over the years, a number of methods have been developed to diagnose and monitor the degradation/aging of the transformer internal insulation system. Some of this degradation/aging can be assessed from electrical responses. Currently there are a variety of electrical-based diagnostic techniques available for insulation condition monitoring of power transformers. In most cases, the electrical signals being monitored are due to mechanical or electric changes caused by physical changes in resistivity, inductance or capacitance, moisture, contamination or aging by-products in the insulation. This paper presents a description of commonly used and modern electrical-based diagnostic techniques along with their interpretation schemes.
Multi-image gradient-based algorithms for motion measurement using wavelet transform
Institute of Scientific and Technical Information of China (English)
2008-01-01
A multi-image wavelet transform motion estimation algorithm based on gradient methods is presented by using the characteristic of wavelet transfom.In this algorithm,the accuracy can be improved greatly using data in many images to measure motions between two images.In combination with the reliability measure for constraints function,the reliable data constraints of the images were decomposed with multi-level simultaneous wavelet transform rather than the traditional coarse-to-fine approach.Compared with conventional methods,this motion measurement algorithm based on multi-level simultaneous wavelet transform avoids propagating errors between the decomposed levels.Experimental simulations show that the implementation of this algo rithm is simple,and the measurement accuracy is improved.
Dual tree complex wavelet transform based denoising of optical microscopy images.
Bal, Ufuk
2012-12-01
Photon shot noise is the main noise source of optical microscopy images and can be modeled by a Poisson process. Several discrete wavelet transform based methods have been proposed in the literature for denoising images corrupted by Poisson noise. However, the discrete wavelet transform (DWT) has disadvantages such as shift variance, aliasing, and lack of directional selectivity. To overcome these problems, a dual tree complex wavelet transform is used in our proposed denoising algorithm. Our denoising algorithm is based on the assumption that for the Poisson noise case threshold values for wavelet coefficients can be estimated from the approximation coefficients. Our proposed method was compared with one of the state of the art denoising algorithms. Better results were obtained by using the proposed algorithm in terms of image quality metrics. Furthermore, the contrast enhancement effect of the proposed method on collagen fıber images is examined. Our method allows fast and efficient enhancement of images obtained under low light intensity conditions.
EMD and Wavelet Transform Based Fault Diagnosis for Wind Turbine Gear Box
Directory of Open Access Journals (Sweden)
Qingyu Yang
2013-01-01
Full Text Available Wind turbines are mainly located in harsh environment, and the maintenance is therefore very difficult. The wind turbine faults are mostly from the gear box, and the fault signal is generally nonlinear and nonstationary. The traditional fault diagnosis methods such as Fast Fourier transform (FFT and the inverted frequency spectrum identification method based on FFT are not satisfactory in processing this kind of signal. This paper proposes a hybrid fault diagnosis method which combines the empirical mode decomposition (EMD and wavelet transform. The vibration signal is analyzed through wavelet transform, and the aliasing in high-frequency signals is then addressed by conducting EMD to the original signals. The experimental results based on a specific wind turbine gear box demonstrate that this method can diagnose the faults and locate their positions accurately.
Experimental validation of ultra-thin metalenses for N-beam emissions based on transformation optics
Energy Technology Data Exchange (ETDEWEB)
Zhang, Kuang, E-mail: zhangkuang@hit.edu.cn [Department of Microwave Engineering, Harbin Institute of Technology, Harbin 150001 (China); State Key Laboratory of Millimeter Waves, Nanjing 210096 (China); Ding, Xumin; Meng, Fanrong; Wu, Qun [Department of Microwave Engineering, Harbin Institute of Technology, Harbin 150001 (China); Wo, Deliang [Shang Hai Electro-Mechanical Engineering Institute, Shanghai 201109 (China)
2016-02-01
A general design of metalenses for N-beam emissions is proposed based on transformation optics. A linear mapping function is adopted to achieve the homogeneous characterization of the transforming medium, which is therefore easy to be achieved compared with previous designs limited by inhomogeneity based on transformation optics. To verify the theoretical design, a four-beam antenna constructed with ultrathin, homogenous, and uniaxial anisotropic metalens is designed, fabricated, and measured. It is shown that the realized gain of the four-beam antenna is increased by 6 dB compared with the single dipole source, while working frequency and relative bandwidth are kept unchanged. The measured far-field pattern verifies theoretical design procedure.
Wang, Shouyu; Yan, Keding; Xue, Liang
2017-01-01
In order to obtain high contrast images and detailed descriptions of label free samples, quantitative interferometric microscopy combining with phase retrieval is designed to obtain sample phase distributions from fringes. As accuracy and efficiency of recovered phases are affected by phase retrieval methods, thus approaches owning higher precision and faster processing speed are still in demand. Here, two dimensional Hilbert transform based phase retrieval method is adopted in cellular phase imaging, it not only reserves more sample specifics compared to classical fast Fourier transform based method, but also overcomes disadvantages of traditional algorithm according to Hilbert transform which is a one dimensional processing causing phase ambiguities. Both simulations and experiments are provided, proving the proposed phase retrieval approach can acquire quantitative sample phases with high accuracy and fast speed.
DC Bias Simulation of 1000 kV UHV Transformer Based on MATLAB / Simulink
Peng, Hu; Yongjun, Yu; Weili, Wu; Fan, Sun; Xiaoxiao, Qi; Yong, Liu
2017-07-01
In order to study the effect of Direct Current bias on the excitation current of 1000kV UHV transformer caused by the parallel operation of DC transmission and AC transmission, this paper builds a simulation model of 1000kV three-winding autotransformer based on MATLAB/Simulink This paper introduces the simulation model of simulation model parameters, and builds a simulation model of 1000kV UHV AC transmission system. Based on the analysis of the change trend of excitation current when the DC voltage source is applied at the neutral point of the transformer, 1000kV transformer, the conclusion is that the DC bias suppression measures and the transmission line design work to provide a theoretical reference.
A new method of medical image fusion based on nonsubsampled contourlet transform
Xu, Xuebin; Zhang, Xinman; Zhang, Deyun
2008-12-01
To improve the normal medical image fusion algorithm in order to avoid the loss of the detailed information in the processes of medical image fusion, a multiscale medical image fusion method based on nonsubsampled contourlet transform(NSCT) is proposed in this paper. First, the source images(MRI and CT images) are decomposed by using nonsubsampled contourlet transform. Then, the details of contourlet coefficients are fused on each corresponding levels with a vision feature fusion operator. Finally, the fused image will be obtained by taking the inverse nonsubsampled contourlet transformation. The experimental results show that the effect of the nonsubsampled contourlet-based method is obviously improved, and the proposed method can effectively preserve the detailed information of the source images.
Region-based image denoising through wavelet and fast discrete curvelet transform
Gu, Yanfeng; Guo, Yan; Liu, Xing; Zhang, Ye
2008-10-01
Image denoising always is one of important research topics in the image processing field. In this paper, fast discrete curvelet transform (FDCT) and undecimated wavelet transform (UDWT) are proposed for image denoising. A noisy image is first denoised by FDCT and UDWT separately. The whole image space is then divided into edge region and non-edge regions. After that, wavelet transform is performed on the images denoised by FDCT and UDWT respectively. Finally, the resultant image is fused through using both of edge region wavelet cofficients of the image denoised by FDCT and non-edge region wavelet cofficients of the image denoised by UDWT. The proposed method is validated through numerical experiments conducted on standard test images. The experimental results show that the proposed algorithm outperforms wavelet-based and curvelet-based image denoising methods and preserve linear features well.
The Path Selections of the Resource-based Cities Transformation in China
Jinhuang Mao
2014-01-01
The transformation of resource-based cities, a worldwide problem, is a broad, cross-cutting and complex issue, which involves many fields of economics, sociology, geography, mining science and ecology. Therefore, the development of resource-based cities in China has been a top priority among researchers. In this paper, the author will work out the best pattern and path of resource-based cities by researching on transition modes, approaches and policies.
Super-resolution image restoration algorithms based on orthogonal discrete wavelet transform
Liu, Yang-yang; Jin, Wei-qi
2005-02-01
Several new super-resolution image restoration algorithms based on orthogonal discrete wavelet transform are proposed, by using orthogonal discrete wavelet transform and generalized cross validation ,and combining with Luck-Richardson super-resolution image restoration algorithm (LR) and Luck-Richardson algorithm based on Poisson-Markov model (MPML). Orthogonal discrete wavelet transform analyzed in both space and frequency domain has the capability of indicating local features of a signal, and concentrating the signal power to a few coefficients in wavelet transform domain. After an original image is "Symlets" orthogonal discrete wavelet transformed, an asymptotically optimal threshold is determined by minimizing generalized cross validation, and high frequency subbands in each decomposition level are denoised with soft threshold processes to converge respectively to those with maximum signal-noise-ratio, when the method is incorporated with existed super-resolution image algorithms, details of original image, especially of those with low signal-noise-ratio, could be well recovered. Single operation wavelet LR algorithm(SWLR),single operation wavelet MPML algorithm(SW-MPML) and MPML algorithm based on single operation and wavelet transform (MPML- SW) are some operative algorithms proposed based on the method. According to the processing results to simulating and practical images , because of the only one operation, under the guarantee of rapid and effective restoration processing, in comparison with LR and MPML, all the proposed algorithms could retain image details better, and be more suitable to low signal-noise-ratio images, They could also reduce operation time for up to hundreds times of iteratives, as well as, avoid the iterative operation of self-adaptive parameters in MPML, improve operating speed and precision. They are practical and instantaneous to some extent in the field of low signal-noise-ratio image restoration.
A Review on Properties, Opportunities, and Challenges of Transformer Oil-Based Nanofluids
Directory of Open Access Journals (Sweden)
Muhammad Rafiq
2016-01-01
Full Text Available The mineral oil or synthetic oil in conjunction with paper is mainly being applied as dielectric medium in many of the high voltage apparatus. However, the advent of high voltage levels such high voltage alternating current (HVAC and high voltage direct current (HVDC has prompted researchers to direct their focus onto an insulation system which can bear the rising high voltage levels. The modern insulating liquid material development is guided by various factors such as high electrical insulation requirements and other safety and economic considerations. Therefore transformer manufacturer companies have to design transformers with these new specific requirements. The transformer oil-based nanofluids with improved dielectric and thermal properties have the potential to replace mineral oil base products in the market place. They are favorable because they function more superior than mineral oil and they contribute definite insulating and thermal gains. This paper reviews recent status of nanofluids use as transformer oils. The nanofluids used as transformer oils are presented and their advantages are described in comparison with mineral oil. The multiple experimental works carried out by different researchers are described, providing an overview of the current research conducted on nanofluids. In addition scope and challenges being confronted in this area of research are clearly presented.
Design parameter based method of partial discharge detection and location in power transformers
Directory of Open Access Journals (Sweden)
Kumar Santosh Annadurai
2009-01-01
Full Text Available Insulation defect detection in time ensures higher operational reliability of power system assets. Power transformers are the most critical unit of power systems both from economical and operational front. Hence it becomes necessary to have knowledge of the actual insulation condition of transformer to increase dependability of the system. The performance and ageing of the transformer insulation is mainly affected by Partial discharges (PD. Proper diagnosis in terms of amplitude and location of partial discharge in a power transformer enables us to predict well in advance, with much confidence, the defect in insulation system, which avoids large catastrophic failures. In this work a 20kVA, 230/50kV single phase core type transformer is used for evaluation of the transfer function-based partial discharge detection and location using modeling of the winding, using design data. The simulation of capturing on-line PD pulses across the bushing tap capacitor is done for various tap positions. Standard PD source model is used to inject PD pulse signal at 10 tap locations in the winding and corresponding response signatures are captured at the bushing tap end (across 1000pF. The equivalent high frequency model of the winding is derived from the design parameters using analytical calculations and simulations in packages such as MAGNET and ANSOFT. The test conditions are simulated using ORCAD-9 and the results are evaluated for location accuracy using design parameter based PD monitoring method. .
A NOVEL BIOMETRICS TRIGGERED WATERMARKING OF IMAGES BASED ON WAVELET BASED CONTOURLET TRANSFORM
Directory of Open Access Journals (Sweden)
Elakkiya Soundar
2013-01-01
Full Text Available The rapid development of network and digital technology has led to several issues to the digital content. The technical solution to provide law enforcement and copyright protection is achieved by digital watermarking Digital watermarking is the process of embedding information into a digital image in a way that is difficult to remove. The proposed method contains following phases (i Pre-processing of biometric image (ii key generation from the biometrics of the owner/user and randomization of the host image using Speeded-Up Robust Features (SURF (iii Wavelet-Based Contourlet Transform (WBCT is applied on the host image. The WBCT can give the anisotropy optimal representation of the edges and contours in the image by virtue of the characteristics of multi-scale framework and multi-directionality (iv Singular Value Decomposition (SVD is enforced over the watermark image (v Embedding of the host image with the watermark image. The comparative analysis confirms the efficiency and robustness of the proposed system Index Terms— Digital Watermarking, copyright, Pre-processing, wavelet, Speeded-Up Robust Features.
Claverys, J P; Méjean, V; Gasc, A M; Sicard, A M
1983-10-01
Genetic transformation in Streptococcus pneumoniae involves the insertion of single-stranded pieces of donor DNA into a recipient genome. Efficiencies of transformation strongly depend on the mutations (markers) carried by donor DNA. Markers are classified according to their transforming efficiencies into very high, high, intermediate, and low efficiency. The last is approximately 1/20th as efficient as the first. This marker effect is under the control of the Hex system, which is thought to correct mismatches at the donor-recipient heteroduplex stage in transformation. To investigate this effect, wild type, mutant, and revertant DNA sequences at five genetic sites within the amiA locus were determined. The results show that low-efficiency markers arise from transitional changes A . T to G . C. The transversion A . T to T . A corresponds to an intermediate-efficiency marker. Transversions G . C to T . A and G . C to C . G lead to high-efficiency markers. Among the eight possible mismatches that could exist transiently at the heteroduplex stage in transformation, only two--namely, A/G and C/C--are not corrected by the Hex system. It is noteworthy that the four possible base pairs (A . T, T . A, G . C, and C . G) have been encountered at the very same site (amiA6 site), which constitutes a good illustration of the marker effect. DNA sequence analysis also reveals that short deletions (33 or 34 bases long) are integrated with very high efficiencies. These results confirm that the Hex system corrects point mismatches harbored in donor-recipient heteroduplexes thousands of bases long. The correction pattern of the Hex system toward multiple-base mismatches has also been investigated. Its behavior toward double-base mismatches is complex, suggesting that neighboring sequences may affect the detection of mispaired bases.
Pedaste, Margus; Sarapuu, Tago
2014-01-01
The aim of this explorative study was to find the factors limiting sixth-grade learners' outcomes in acquiring skills related to the transformative inquiry learning processes as well as to analyse the interrelations between inquiry skills in order to develop an optimal support system for designing Web-based inquiry learning environments. A…
Mechanism of Process-Induced Salt-to-Free Base Transformation of Pharmaceutical Products
DEFF Research Database (Denmark)
Bruun Hansen, Thomas; Qu, Haiyan
2014-01-01
pH-solubility profiles of a model drug in salt form was established and the mechanism of salt-to-free base form transformation was investigated by increasing pH of the system. Wet massing experiments along with suspension experiments were used to investigate the effects of excipients on the stabi...
Determination of Transmission Routing of OXC Nodes Based on AWG Multiplexer by Matrix Transformation
Institute of Scientific and Technical Information of China (English)
GUO Ai-huang; FU Jun-mei
2004-01-01
The structures of the space switching and the wavelength switching optical cross connect (OXC)nodes which are based on the arrayed waveguide grating (AWG) multiplexer are analyzed. By the matrix transformation relation between the input and output wavelengths of the AWG multiplexer, the wavelength transmission routings of the space switching and wavelength switching OXC nodes are determined.
PCB Slot Based Transformers to Avoid Common-Mode Resonances in Connected Arrays of Dipoles
Cavallo, D.; Neto, A.; Gerini, G.
2010-01-01
The scanning performances of connected arrays are degraded by the excitation of common-mode resonances that are compatible with balanced feeding lines. Here, a strategy to avoid these resonances is outlined. The strategy involves feeding the dipoles via printed circuit board (PCB) based transformers
An imaging algorithm based on keystone transform for one-stationary bistatic SAR of spotlight mode
Qiu, Xiaolan; Behner, Florian; Reuter, Simon; Nies, Holger; Loffeld, Otmar; Huang, Lijia; Hu, Donghui; Ding, Chibiao
2012-12-01
This article proposes an imaging algorithm based on Keystone Transform for bistatic SAR with a stationary receiver. It can efficiently be applied to high-resolution spotlight mode, and can directly be process the bistatic SAR data which have been ranged compressed by the synchronization reference pulses. Both simulation and experimental results validate the good performance of this algorithm.
A Transformational Approach to VHDL and CDFG Based High-Level Synthesis: a Case Study
Middelhoek, Peter F.A.; Mekenkamp, Gerhard E.; Molenkamp, Bert E.; Krol, Thijs
1995-01-01
In this paper, a novel multi-target design methodology based on the concepts of transformational design, and its application to the interlaced-to-progressive scan conversion (IPSC) problem, are discussed. Starting from a single high-level behavioral specification in VHDL a direction detector used in
Morgan, Haydn J.; Bush, Anthony J.
2016-01-01
Reducing social exclusion through interventions designed to sustain school engagement is a key aim of the education and social policy of any government. This paper is a response to the call for there to be more focused empirical sports coaching research through examining the transformative potential of community-based sports coaches to support…
To Be Transformed: Emotions in Cross-Cultural, Field-Based Learning in Northern Australia
Wright, Sarah; Hodge, Paul
2012-01-01
Students undertaking field-based learning, in which they work with Indigenous people in Northern Australia, describe a profound learning experience redolent with emotion. Inspired, challenged and transformed, the students are compelled in ways that require them to interrogate their own selves and taken-for-granted beliefs. In this paper, we draw…
Managing the PSTN transformation a blueprint for a successful migration to IP-based networks
Dornheim, Sandra
2015-01-01
While there are many scholarly books and papers that cover the technical issues behind the public switched telephone network (PSTN) migration, few books describe exactly how to manage the migration process economically. Filling this need, Managing the PSTN Transformation: A Blueprint for a Successful Migration to IP-Based Networks reflects the latest understanding of the challenges behind migrating customers from the old PSTN network to an IP infrastructure. The IP transformation blueprint described in this book is not a theoretical cookbook that describes how this could work. Instead, the boo
Feng, Ziang; Gao, Zhan; Zhang, Xiaoqiong; Wang, Shengjia; Yang, Dong; Yuan, Hao; Qin, Jie
2015-09-01
Digital shearing speckle pattern interferometry (DSSPI) has been recognized as a practical tool in testing strain. The DSSPI system which is based on temporal analysis is attractive because of its ability to measure strain dynamically. In this paper, such a DSSPI system with Wollaston prism has been built. The principles and system arrangement are described and the preliminary experimental result of the displacement-derivative test of an aluminum plate is shown with the wavelet transformation method and the Fourier transformation method. The simulations have been conducted with the finite element method. The comparison of the results shows that quantitative measurement of displacement-derivative has been realized.
Dynamic optimum dead time in piezoelectric transformer-based switch-mode power supplies
DEFF Research Database (Denmark)
Ekhtiari, Marzieh; Andersen, Thomas; Andersen, Michael A. E.;
2016-01-01
Soft switching is required to attain high efficiency in high-frequency power converters. Piezoelectric transformerbased converters can benefit from soft switching in terms of significantly diminished switching losses and stresses. Adequate dead time is needed in order to deliver sufficient energy...... to charge and discharge the input capacitance of piezoelectric transformers in order to achieve zero-voltage switching. This paper proposes a method for detecting the optimum dead time in piezoelectric transformer-based switch-mode power supplies. The provision of sufficient dead time in every cycle...
DEFF Research Database (Denmark)
S. El Moursi, Mohamed; Bak-Jensen, Birgitte; Abdel-Rahman, Mansour Hassan
2011-01-01
and optimal tracking secondary voltage control for wind parks based on self-excited induction generators which comprise STATCOM and under-load tap changer (ULTC) substation transformers. The voltage controllers for the STATCOM and ULTC transformer are coordinated and ensure the voltage support. In steady......-state operation, the voltage is controlled by only stepping the tap changer when the voltage is outside the deadband region of the ULTC to minimize the number of taps changes. Thus, the STATCOM will be unloaded and ready to react with higher reactive power margin during contingencies. In the paper, the effects...
Color pattern recognition based on the joint fractional Fourier transform correlator
Institute of Scientific and Technical Information of China (English)
Weimin Jin; Yupei Zhang
2007-01-01
A new system of multi-channel single-output joint fractional Fourier transform correlator (JFRTC) for color pattern recognition is proposed based on the conventional system of multi-channel single-output joint transform correlator (JTC). The theoretical analysis and optical experiments are performed. With this method, one can obtain three correlation peaks at the output plane which show a pair of desired cross-correlation peaks and one auto-correlation peak. In comparison, the conventional system leads to more correlation peaks playing a noise role in color pattern recognition.
Audio watermarking based on psychoacoustic model and critical band wavelet transform
Institute of Scientific and Technical Information of China (English)
TAO Zhi; ZHAO Heming; GU Jihua; WU Di
2007-01-01
Watermark embedding algorithm based on critical band wavelet transform of digital audio signal is proposed in this paper. The masking threshold for each audio signal segment was calculated on the basic of psychoacoustic model. According to the similarity between critical band of human auditory system and critical band wavelet transform, a watermark was embedded into the low-band and mid-band coefficients of digital wavelet. The embedding strength was adaptively controlled by the masking threshold. The experiment results show that the embedded watermark signal is inaudible, and the watermarked audio signal has good robustness against many attacks such as compression, noise, re-sampling, low-pass filtering.
A method of image compression based on lifting wavelet transform and modified SPIHT
Lv, Shiliang; Wang, Xiaoqian; Liu, Jinguo
2016-11-01
In order to improve the efficiency of remote sensing image data storage and transmission we present a method of the image compression based on lifting scheme and modified SPIHT(set partitioning in hierarchical trees) by the design of FPGA program, which realized to improve SPIHT and enhance the wavelet transform image compression. The lifting Discrete Wavelet Transform (DWT) architecture has been selected for exploiting the correlation among the image pixels. In addition, we provide a study on what storage elements are required for the wavelet coefficients. We present lena's image using the 3/5 lifting scheme.
[The principle and analysis of micro-Fourier transform spectrometer based on MEMS micro-mirror].
Chen, Jian-Jun; Zhu, Yong; Liu, Bo; Wei, Wei; Zhang, Jie; Wang, Ning
2012-11-01
The present paper puts forward a novel micro-Fourier transform infrared spectrometer based on programmable MEMS micro-mirror. This design uses a MEMS micro-mirror and a slantwise reflector to replace the moving mirror system on traditional spectrometer. This paper analyzes the operating principle of this spectrometer and gives the simulation result to prove the feasibility of this method. The results show that the spectral resolution is less than 5 nm in near-infrared wave band, the wave-length accuracy is approximately 1 nm and the sampling period of this spectrometer is approximately 50 ms. This method can use Hadamard transform to improve the SNR.
An Improved Singularity Computing Algorithm Based on Wavelet Transform Modulus Maxima Method
Institute of Scientific and Technical Information of China (English)
ZHAO Jian; XIE Duan; FAN Xun-li
2006-01-01
In order to reduce the hidden danger of noise which can be charactered by singularity spectrum, a new algorithm based on wavelet transform modulus maxima method was proposed. Singularity analysis is one of the most promising new approaches for extracting noise hidden information from noisy time series . Because of singularity strength is hard to calculate accurately, a wavelet transform modulus maxima method was used to get singularity spectrum. The singularity spectrum of white noise and aluminium interconnection electromigration noise was calculated and analyzed. The experimental results show that the new algorithm is more accurate than tradition estimating algorithm. The proposed method is feasible and efficient.
Tatulli, Eric
2013-04-01
This paper studies the effects on Zernike coefficients of aperture scaling, translation, and rotation, when a given aberrated wavefront is described on the Zernike polynomial basis. It proposes an analytical method for computing the matrix that enables the building of transformed Zernike coefficients from the original ones. The technique is based on the properties of Zernike polynomials and Fourier transform, and, in the case of a full aperture without central obstruction, the coefficients of the matrix are given in terms of integrals of Bessel functions. The integral formulas are exact and do not depend on any specific ordering of the polynomials.
Temperature of phase transformations in heat-resistant nickel-base alloys
Ivanov, A. D.; Ukhlinov, A. G.
1997-11-01
The study of phase transformations in heating and cooling of alloys is needed for choosing optimum regimes of their melting, plastic deformation, and heat treatment. In the present paper differential thermal analysis is used to determine the temperature of phase transformations in complexly alloyed nickel-base alloys. Industrial nickel alloys with intermetallic reinforcement manufactured by means of vacuum arc remelting (VAR) and hot deformation (HD) were studied. Alloy KhN56MBYuD was studied after different metallurgical processes, namely, electroslag remelting (ESR), centrifugal casting (CC), powder spraying (PS), and hot isostatic pressing (HIP). All the alloys were studied in the initial state and after heat treatment.
Optimizing efficiency on conventional transformer based low power AC/DC standby power supplies
DEFF Research Database (Denmark)
Nielsen, Nils
2004-01-01
This article describes the research results for simple and cheap methods to reduce the idle- and load-losses in very low power conventional transformer based power supplies intended for standby usage. In this case "very low power" means 50 Hz/230 V-AC to 5 V-DC@1 W. The efficiency is measured...... on two common power supply topologies designed for this power level. The two described topologies uses either a series (or linear) or a buck regulation approach. Common to the test power supplies is they either are using a standard cheap off-the-shelf transformer, or one, which are loss optimized by very...
Cheng, Z.; Chen, Y.; Liu, Y.; Liu, W.; Zhang, G.
2015-12-01
Among those hydrocarbon reservoir detection techniques, the time-frequency analysis based approach is one of the most widely used approaches because of its straightforward indication of low-frequency anomalies from the time-frequency maps, that is to say, the low-frequency bright spots usually indicate the potential hydrocarbon reservoirs. The time-frequency analysis based approach is easy to implement, and more importantly, is usually of high fidelity in reservoir prediction, compared with the state-of-the-art approaches, and thus is of great interest to petroleum geologists, geophysicists, and reservoir engineers. The S transform has been frequently used in obtaining the time-frequency maps because of its better performance in controlling the compromise between the time and frequency resolutions than the alternatives, such as the short-time Fourier transform, Gabor transform, and continuous wavelet transform. The window function used in the majority of previous S transform applications is the symmetric Gaussian window. However, one problem with the symmetric Gaussian window is the degradation of time resolution in the time-frequency map due to the long front taper. In our study, a bi-Gaussian S transform that substitutes the symmetric Gaussian window with an asymmetry bi-Gaussian window is proposed to analyze the multi-channel seismic data in order to predict hydrocarbon reservoirs. The bi-Gaussian window introduces asymmetry in the resultant time-frequency spectrum, with time resolution better in the front direction, as compared with the back direction. It is the first time that the bi-Gaussian S transform is used for analyzing multi-channel post-stack seismic data in order to predict hydrocarbon reservoirs since its invention in 2003. The superiority of the bi-Gaussian S transform over traditional S transform is tested on a real land seismic data example. The performance shows that the enhanced temporal resolution can help us depict more clearly the edge of the
Gundreddy, Rohith Reddy; Tan, Maxine; Qui, Yuchen; Zheng, Bin
2015-03-01
The purpose of this study is to develop and test a new content-based image retrieval (CBIR) scheme that enables to achieve higher reproducibility when it is implemented in an interactive computer-aided diagnosis (CAD) system without significantly reducing lesion classification performance. This is a new Fourier transform based CBIR algorithm that determines image similarity of two regions of interest (ROI) based on the difference of average regional image pixel value distribution in two Fourier transform mapped images under comparison. A reference image database involving 227 ROIs depicting the verified soft-tissue breast lesions was used. For each testing ROI, the queried lesion center was systematically shifted from 10 to 50 pixels to simulate inter-user variation of querying suspicious lesion center when using an interactive CAD system. The lesion classification performance and reproducibility as the queried lesion center shift were assessed and compared among the three CBIR schemes based on Fourier transform, mutual information and Pearson correlation. Each CBIR scheme retrieved 10 most similar reference ROIs and computed a likelihood score of the queried ROI depicting a malignant lesion. The experimental results shown that three CBIR schemes yielded very comparable lesion classification performance as measured by the areas under ROC curves with the p-value greater than 0.498. However, the CBIR scheme using Fourier transform yielded the highest invariance to both queried lesion center shift and lesion size change. This study demonstrated the feasibility of improving robustness of the interactive CAD systems by adding a new Fourier transform based image feature to CBIR schemes.
Directory of Open Access Journals (Sweden)
Xiaoming Xi
2013-07-01
Full Text Available Retinal identification based on retinal vasculatures in the retina provides the most secure and accurate means of authentication among biometrics and has primarily been used in combination with access control systems at high security facilities. Recently, there has been much interest in retina identification. As digital retina images always suffer from deformations, the Scale Invariant Feature Transform (SIFT, which is known for its distinctiveness and invariance for scale and rotation, has been introduced to retinal based identification. However, some shortcomings like the difficulty of feature extraction and mismatching exist in SIFT-based identification. To solve these problems, a novel preprocessing method based on the Improved Circular Gabor Transform (ICGF is proposed. After further processing by the iterated spatial anisotropic smooth method, the number of uninformative SIFT keypoints is decreased dramatically. Tested on the VARIA and eight simulated retina databases combining rotation and scaling, the developed method presents promising results and shows robustness to rotations and scale changes.
Wu, Xuebin
2011-01-01
Long Reed-Solomon (RS) codes are desirable for digital communication and storage systems due to their improved error performance, but the high computational complexity of their decoders is a key obstacle to their adoption in practice. As discrete Fourier transforms (DFTs) can evaluate a polynomial at multiple points, efficient DFT algorithms are promising in reducing the computational complexities of syndrome based decoders for long RS codes. In this paper, we first propose partial composite cyclotomic Fourier transforms (CCFTs) and then devise syndrome based decoders for long RS codes over large finite fields based on partial CCFTs. The new decoders based on partial CCFTs achieve a significant saving of computational complexities for long RS codes. Since partial CCFTs have modular and regular structures, the new decoders are suitable for hardware implementations. To further verify and demonstrate the advantages of partial CCFTs, we implement in hardware the syndrome computation block for a $(2720, 2550)$ sho...
Digitized self-oscillating loop for piezoelectric transformer-based power converters
DEFF Research Database (Denmark)
Ekhtiari, Marzieh; Andersen, Thomas; Zhang, Zhe
2016-01-01
frequency control and ensures an optimum operation of the piezoelectric transformer in terms of voltage gain and efficiency. In this work, additional time delay is implemented digitally for the first time through 16 bit digital-to-analog converter to the self-oscillating loop. Delay control setpoints......A new method is implemented in designing of self-oscillating loop for driving piezoelectric transformers. The implemented method is based on combining both analog and digital control systems. Digitized delay, or digitized phase shift through the self-oscillating loop results in a very precise...... updates at a rate of 417 kHz. This allows the control loop to dynamically follow frequency changes of the transformer in each resonant cycle. The operation principle behind self-oscillating is discussed in this paper. Moreover, experimental results are reported....
[A method of object detection for remote sensing-imagery based on spectral space transformation].
Wu, Gui-Ping; Xiao, Peng-Feng; Feng, Xue-Zhi; Wang, Ke
2013-03-01
Object detection is an intermediate link for remote sensing image processing, which is an important guarantee of remote sensing application and services aspects. In view of the characteristics of remotely sensed imagery in frequency domain, a novel object detection algorithm based on spectral space transformation was proposed in the present paper. Firstly, the Fourier transformation method was applied to transform the image in spatial domain into frequency domain. Secondly, the wedge-shaped sample and overlay analysis methods for frequency energy were used to decompose signal into different frequency spectrum zones, and the center frequency values of object's features were acquired as detection marks in frequency domain. Finally, object information was detected with the matched Gabor filters which have direction and frequency selectivity. The results indicate that the proposed algorithm here performs better and it has good detection capability in specific direction as well.
Kong, Gang; Dai, Dao-Qing; Zou, Lu-Min
2008-07-01
In order to remove the artifacts of peripheral digital subtraction angiography (DSA), an affine transformation-based automatic image registration algorithm is introduced here. The whole process is described as follows: First, rectangle feature templates are constructed with their centers of the extracted Harris corners in the mask, and motion vectors of the central feature points are estimated using template matching technology with the similarity measure of maximum histogram energy. And then the optimal parameters of the affine transformation are calculated with the matrix singular value decomposition (SVD) method. Finally, bilinear intensity interpolation is taken to the mask according to the specific affine transformation. More than 30 peripheral DSA registrations are performed with the presented algorithm, and as the result, moving artifacts of the images are removed with sub-pixel precision, and the time consumption is less enough to satisfy the clinical requirements. Experimental results show the efficiency and robustness of the algorithm.
Welding temperature field analysis for featheredged cylinder based upon conformal transformation
Institute of Scientific and Technical Information of China (English)
Zhang Guodong; Zhang Fuju
2006-01-01
The accurate calculation and measurement of welding temperature field is an important precondition for welding metallurgical analysis and welding process controlling. In this paper, the conformal transformation is firstly used to analyze the welding temperature field of featheredged cylinder. The center of the cylinder is chosen as the origin of column coordinate system, and every point may be expressed as complex field vector. The branch isogonality counterchanges the line parallel with the fusion line in half-infinite z-plane to the circle concentric with the fusion line in infinite cylinder. The Laplace equation and Poisson's equation still keep validity, so the temperature field equation can be solved. The conformal transformation and equation solution is processed by Matlab program language. It shows that the obtained analytical modeling of temperature field for featheredged cylinder based on conformal transformation is effective and accurate.
Research on Method of Character Recognition Based on Hough Transform and RBF Neural Network
Directory of Open Access Journals (Sweden)
Zhang Yin
2015-01-01
Full Text Available A method of character recognition based on Hough transform and RBF neural network is proposed through research on weight accumulation algorithm of Hough transform. According to the feature of characters’ structure by using the duality of point-line Hough transform was done. In this method, the number of the points on the same line in parameter space and the position coordinates of the elements in image mapping space were taken to RBF neural network recognition system as characteristic input vector. It reduced the dimension of character feature vector and reflected the overall distribution of character lattice and the essential feature of character shape. The simulation results indicated there were some merits in this improved method: capability of recognition is strong, the quantity of calculation is small, and the speed of calculation is quick.
Image encryption based on the reality-preserving multiple-parameter fractional Fourier transform
Lang, Jun
2012-05-01
In recent years, a number of methods have been proposed in the literature for the encryption of two-dimensional information by using the fractional Fourier transform, but most of their encryptions are complex values and need digital hologram technique to record information, which is inconvenient for digital transmission. In this paper, we propose a new approach for image encryption based on the real-valuedness and decorrelation property of the reality-preserving multiple-parameter fractional Fourier transform in order to meet the requirements of the secure image transmission. In the proposed scheme, the original and encrypted images are respectively in the spatial domain and the reality-preserving multiple-parameter fractional Fourier transformed domain determined by the encryption keys. Numerical simulations are performed to demonstrate that the proposed method is reliable and more robust to blind decryption than several existing methods.
Implementation of Texture Based Image Retrieval Using M-band Wavelet Transform
Institute of Scientific and Technical Information of China (English)
LiaoYa-li; Yangyan; CaoYang
2003-01-01
Wavelet transform has attracted attention because it is a very useful tool for signal analyzing. As a fundamental characteristic of an image, texture traits play an important role in the human vision system for recognition and interpretation of images. The paper presents an approach to implement texture-based image retrieval using M-band wavelet transform. Firstly the traditional 2-band wavelet is extended to M-band wavelet transform. Then the wavelet moments are computed by M-band wavelet coefficients in the wavelet domain. The set of wavelet moments forms the feature vector related to the texture distribution of each wavelet images. The distances between the feature vectors describe the similarities of different images. The experimental result shows that the M-band wavelet moment features of the images are effective for image indexing.The retrieval method has lower computational complexity, yet it is capable of giving better retrieval performance for a given medical image database.
Implementation of Texture Based Image Retrieval Using M-band Wavelet Transform
Institute of Scientific and Technical Information of China (English)
Liao Ya-li; Yang Yan; Cao Yang
2003-01-01
Wavelet transform has attracted attention because it is a very useful tool for signal analyzing. As a fundamental characteristic of an image, texture traits play an important role in the human vision system for recognition and interpretation of images. The paper presents an approach to implement texture-based image retrieval using M-band wavelet transform. Firstly the traditional 2-band wavelet is extended to M-band wavelet transform. Then the wavelet moments are computed by M-band wavelet coefficients in the wavelet domain. The set of wavelet moments forms the feature vector related to the texture distribution of each wavelet images. The distances between the feature vectors describe the similarities of different images. The experimental result shows that the M-band wavelet moment features of the images are effective for image indexing. The retrieval method has lower computational complexity, yet it is capable of giving better retrieval performance for a given medical image database.
Entropy-Based Bagging for Fault Prediction of Transformers Using Oil-Dissolved Gas Data
Directory of Open Access Journals (Sweden)
Weigen Chen
2011-08-01
Full Text Available The development of the smart grid has resulted in new requirements for fault prediction of power transformers. This paper presents an entropy-based Bagging (E-Bagging method for prediction of characteristic parameters related to power transformers faults. A parameter of comprehensive information entropy of sample data is brought forward to improve the resampling process of the E-Bagging method. The generalization ability of the E-Bagging is enhanced significantly by the comprehensive information entropy. A total of sets of 1200 oil-dissolved gas data of transformers are used as examples of fault prediction. The comparisons between the E-Bagging and the traditional Bagging and individual prediction approaches are presented. The results show that the E-Bagging possesses higher accuracy and greater stability of prediction than the traditional Bagging and individual prediction approaches.
Dissolved Gas-in-Oil Analysis in Transformers Based on Near-Infrared Photoacoustic Spectroscopy
Mao, Xuefeng; Zhou, Xinlei; Zhai, Liang; Yu, Qingxu
2015-06-01
This paper investigates an application of near-infrared photoacoustic spectroscopy (PAS) to analyze the dissolved gas-in-oil of a transformer. A near-infrared tunable fiber laser-based PAS system has been developed. Using this system, the gas detection limits (signal-to-noise ratio = 1) of 4 ppb at 1531.59 nm for , 39 ppm at 1565.98 nm for CO, and 34 ppm at 1572.34 are reached. In addition, the fault gas () is produced by a transformer spatial discharge simulation system, and the productivity of the gas is measured quantitatively. The experiment demonstrates the near-infrared PAS system is able to be applied to the dissolved gas analysis of a transformer.
Color Image and Video Compression Based on Direction Adaptive Partitioned Discrete Wavelet Transform
Directory of Open Access Journals (Sweden)
K. Dinesh
2012-12-01
Full Text Available The main objective of this study is to use the Direction-Adaptive Partitioned Block Transform (DA-PBT for compressing the color images and videos. It is same as the direction-adaptive block transform but it also have an additional direction-adaptive block partitioning to improve energy concentration. The selection of a directional mode determines the transform direction that provides directional basis functions. It reduces complexity and more efficient coefficient ordering for entropy coding. For image coding, the DA-PBT significantly outperforms the directional DCT. As a block transform, the DA-PBT can be directly incorporated into the prediction-based video coding standards to work with the block-based intra prediction as well as the block-based motion-compensated interframe prediction. The performance of the DA-PBT is compared with the 2D-DCT by using the Peak-Signal-to- Noise Ratio (PSNR and Compression Ratio (CR. The experimental results shows that the DA-PBT performs well than the 2D-DCT.
Video compression based on enhanced EZW scheme and Karhunen-Loeve transform
Soloveyko, Olexandr M.; Musatenko, Yurij S.; Kurashov, Vitalij N.; Dubikovskiy, Vladislav A.
2000-06-01
The paper presents a new method for video compression based on the enhanced embedded zerotree wavelet (EZW) scheme. Recently, video codecs from the EZW family which use a 3D version of EZW or SPIHT algorithms showed better performance than the MPEG-2 compression algorithm. These algorithms have many advantages inherent for wavelet based schemes and EZW- like coders. Their most important advantages are good compression performance and scalability. However, they still allow improvement in several ways. First, as we recently showed, using Karhunen-Loeve (KL) transform instead of wavelet transform along the time axis improves compression ratio. Second, instead of the 3D EZW quantization scheme, we offer to use a convenient 2D quantization for every decorrelated frame adding one symbol `Strong Zero Tree', which means that every frame from a chosen set has a zero tree in the same location. The suggested compression algorithm based on KL transform, wavelet transform, and a new quantization scheme with strong zerotrees is free from some drawbacks of the plain 3D EZW codec. The presented codec shows 1 - 6 dB better results compared to the MPEG-2 compression algorithm on video sequences with small and medium motion.
Discrete Multiwavelet Critical-Sampling Transform-Based OFDM System over Rayleigh Fading Channels
Directory of Open Access Journals (Sweden)
Sameer A. Dawood
2015-01-01
Full Text Available Discrete multiwavelet critical-sampling transform (DMWCST has been proposed instead of fast Fourier transform (FFT in the realization of the orthogonal frequency division multiplexing (OFDM system. The proposed structure further reduces the level of interference and improves the bandwidth efficiency through the elimination of the cyclic prefix due to the good orthogonality and time-frequency localization properties of the multiwavelet transform. The proposed system was simulated using MATLAB to allow various parameters of the system to be varied and tested. The performance of DMWCST-based OFDM (DMWCST-OFDM was compared with that of the discrete wavelet transform-based OFDM (DWT-OFDM and the traditional FFT-based OFDM (FFT-OFDM over flat fading and frequency-selective fading channels. Results obtained indicate that the performance of the proposed DMWCST-OFDM system achieves significant improvement compared to those of DWT-OFDM and FFT-OFDM systems. DMWCST improves the performance of the OFDM system by a factor of 1.5–2.5 dB and 13–15.5 dB compared with the DWT and FFT, respectively. Therefore the proposed system offers higher data rate in wireless mobile communications.
Abuturab, Muhammad Rafiq
2014-06-01
A new color image security system based on singular value decomposition (SVD) in gyrator transform (GT) domains is proposed. In the encryption process, a color image is decomposed into red, green and blue channels. Each channel is independently modulated by random phase masks and then separately gyrator transformed at different parameters. The three gyrator spectra are joined by multiplication to get one gray ciphertext. The ciphertext is separated into U, S, and V parts by SVD. All the three parts are individually gyrator transformed at different transformation angles. The three encoded information can be assigned to different authorized users for highly secure verification. Only when all the authorized users place the U, S, and V parts in correct multiplication order in the verification system, the correct information can be obtained with all the right keys. In the proposed method, SVD offers one-way asymmetrical decomposition algorithm and it is an optimal matrix decomposition in a least-square sense. The transformation angles of GT provide very sensitive additional keys. The pre-generated keys for red, green and blue channels are served as decryption (private) keys. As all the three encrypted parts are the gray scale ciphertexts with stationary white noise distributions, which have camouflage property to some extent. These advantages enhance the security and robustness. Numerical simulations are presented to support the viability of the proposed verification system.
Block-based SVD image watermarking in spatial and transform domains
Ghazy, Rania A.; Abbas, Alaa M.; Al-Zubi, Nayel; Hassan, Emad S.; El-Fishawy, Nawal A.; Hadhoud, Mohiy M.; Dessouky, Moawad I.; El-Rabaie, El-Sayed M.; Alshebeili, Saleh A.; Abd El-Samie, Fathi E.
2015-07-01
The idea of this paper is to implement an efficient block-by-block singular value (SV) decomposition digital image watermarking algorithm, which is implemented in both the spatial and transforms domains. The discrete wavelet transform (DWT), the discrete cosine transform and the discrete Fourier transform are exploited for this purpose. The original image or one of its transforms is segmented into non-overlapping blocks, and consequently the image to be inserted as a watermark is embedded in the SVs of these blocks. Embedding the watermark on a block-by-block manner ensures security and robustness to attacks such like Gaussian noise, cropping and compression. The proposed algorithm can also be used for colour image watermarking. A comparison study between the proposed block-based watermarking algorithm and the method of Liu is performed for watermarking in all domains. Simulation results ensure that the proposed algorithm is more effective than the traditional method of Liu, especially when the watermarking is performed in the DWT domain.
Institute of Scientific and Technical Information of China (English)
Gou Fu-Yan; Liu Cai; Liu Yang; Feng Xuan; Cui Fang-Zi
2014-01-01
In seismic prospecting,fi eld conditions and other factors hamper the recording of the complete seismic wavefi eld; thus, data interpolation is critical in seismic data processing. Especially, in complex conditions, prestack missing data affect the subsequent high-precision data processing workfl ow. Compressive sensing is an effective strategy for seismic data interpolation by optimally representing the complex seismic wavefi eld and using fast and accurate iterative algorithms. The seislet transform is a sparse multiscale transform well suited for representing the seismic wavefield, as it can effectively compress seismic events. Furthermore, the Bregman iterative algorithm is an efficient algorithm for sparse representation in compressive sensing. Seismic data interpolation methods can be developed by combining seismic dynamic prediction, image transform, and compressive sensing. In this study, we link seismic data interpolation and constrained optimization. We selected the OC-seislet sparse transform to represent complex wavefields and used the Bregman iteration method to solve the hybrid norm inverse problem under the compressed sensing framework. In addition, we used an H-curve method to choose the threshold parameter in the Bregman iteration method. Thus, we achieved fast and accurate reconstruction of the seismic wavefi eld. Model andfi eld data tests demonstrate that the Bregman iteration method based on the H-curve norm in the sparse transform domain can effectively reconstruct missing complex wavefi eld data.
Directory of Open Access Journals (Sweden)
Luo Wei
2017-01-01
Full Text Available Power transformer is one of the most important equipment in power system. In order to predict the potential fault of power transformer and identify the fault types correctly, we proposed a transformer fault intelligent diagnosis model based on chemical reaction optimization (CRO algorithm and relevance vector machine(RVM. RVM is a powerful machine learning method, which can solve nonlinear, high-dimensional classification problems with a limited number of samples. CRO algorithm has well global optimization and simple calculation, so it is suitable to solve parameter optimization problems. In this paper, firstly, a multi-layer RVM classification model was built by binary tree recognition strategy. Secondly, CRO algorithm was adopted to optimize the kernel function parameters which could enhance the performance of RVM classifiers. Compared with IEC three-ratio method and the RVM model, the CRO-RVM model not only overcomes the coding defect problem of IEC three-ratio method, but also has higher classification accuracy than the RVM model. Finally, the new method was applied to analyze a transformer fault case, Its predicted result accord well with the real situation. The research provides a practical method for transformer fault intelligent diagnosis and prediction.
A compact high-voltage pulse generator based on pulse transformer with closed magnetic core.
Zhang, Yu; Liu, Jinliang; Cheng, Xinbing; Bai, Guoqiang; Zhang, Hongbo; Feng, Jiahuai; Liang, Bo
2010-03-01
A compact high-voltage nanosecond pulse generator, based on a pulse transformer with a closed magnetic core, is presented in this paper. The pulse generator consists of a miniaturized pulse transformer, a curled parallel strip pulse forming line (PFL), a spark gap, and a matched load. The innovative design is characterized by the compact structure of the transformer and the curled strip PFL. A new structure of transformer windings was designed to keep good insulation and decrease distributed capacitance between turns of windings. A three-copper-strip structure was adopted to avoid asymmetric coupling of the curled strip PFL. When the 31 microF primary capacitor is charged to 2 kV, the pulse transformer can charge the PFL to 165 kV, and the 3.5 ohm matched load can deliver a high-voltage pulse with a duration of 9 ns, amplitude of 84 kV, and rise time of 5.1 ns. When the load is changed to 50 ohms, the output peak voltage of the generator can be 165 kV, the full width at half maximum is 68 ns, and the rise time is 6.5 ns.
Part 1: Evidence-based facility design using Transforming Care at the Bedside principles.
Devine, Deborah A; Wenger, Barb; Krugman, Mary; Zwink, Jennifer E; Shiskowsky, Kaycee; Hagman, Jan; Limon, Shelly; Sanders, Carolyn; Reeves, Catherine
2015-02-01
An academic hospital used Transforming Care at the Bedside (TCAB) principles as the framework for generating evidence-based recommendations for the design of an expansion of the current hospital. The interdisciplinary team used the table of evidence-based data to advocate for a patient- and family-centered, safe, and positive work environment. A nurse project manager acted as liaison between the TCAB design team, architects, and facilities and design consultants. Part 2 of this series describes project evaluation outcomes.
Investigation of PAPR in Discrete Wavelet Transform based Multi-carrier Systems
Neha S; Thushara S; Ramanathan R
2015-01-01
The objective of the paper is to formulate a measure to reduce PAPR problem in Orthogonal Frequency Division Multiplexing. To mitigate the problem of PAPR, a Discrete Wavelet Transform based system is employed instead of conventional OFDM. For the comparative study, the PAPR in conventional OFDM is analyzed for varying number of subcarriers and for different channel taps. The result of conventional OFDM is compared with wavelet based OFDM, employing wavelets namely - ‘Haar’, ‘Daubechies’, ‘Sy...
Graph-Based Transform for 2D Piecewise Smooth Signals With Random Discontinuity Locations.
Zhang, Dong; Liang, Jie
2017-04-01
The graph-based block transform recently emerged as an effective tool for compressing some special signals such as depth images in 3D videos. However, in existing methods, overheads are required to describe the graph of the block, from which the decoder has to calculate the transform via time-consuming eigendecomposition. To address these problems, in this paper, we aim to develop a single graph-based transform for a class of 2D piecewise smooth signals with similar discontinuity patterns. We first consider the deterministic case with a known discontinuity location in each row. We propose a 2D first-order autoregression (2D AR1) model and a 2D graph for this type of signals. We show that the closed-form expression of the inverse of a biased Laplacian matrix of the proposed 2D graph is exactly the covariance matrix of the proposed 2D AR1 model. Therefore, the optimal transform for the signal are the eigenvectors of the proposed graph Laplacian. Next, we show that similar results hold in the random case, where the locations of the discontinuities in different rows are randomly distributed within a confined region, and we derive the closed-form expression of the corresponding optimal 2D graph Laplacian. The theory developed in this paper can be used to design both pre-computed transforms and signal-dependent transforms with low complexities. Finally, depth image coding experiments demonstrate that our methods can achieve similar performance to the state-of-the-art method, but our complexity is much lower.
Region-based fusion of infrared and visible images using nonsubsampled contourlet transform
Institute of Scientific and Technical Information of China (English)
Baolong Guo; Qiang Zhang; Ye Hou
2008-01-01
With the nonsubsampled contourlet transform (NSCT), a novel region-segmentation-based fusion algorithm for infrared (IR) and visible images is presented.The IR image is segmented according to the physical features of the target.The source images are decomposed by the NSCT, and then, different fusion rules for the target regions and the background regions are employed to merge the NSCT coefficients respectively.Finally, the fused image is obtained by applying the inverse NSCT.Experimental results show that the proposed algorithm outperforms the pixel-based methods, including the traditional wavelet-based method and NSCT-based method.
Li, Zili; Xia, Xuezhi; Zhu, Guangxi; Zhu, Yaoting
2004-03-01
The principle to construct G&IBMR virtual scene based on stereo panorama with binocular stereovision was put forward. Closed cubic B-splines have been used for content-based segmentation to virtual objects of stereo panorama and all objects in current viewing frustum would be ordered in current object linked list (COLL) by their depth information. The formula has been educed to calculate the depth information of a point in virtual scene by the parallax based on a parallel binocular vision model. A bilinear interpolation algorithm has been submitted to deform the segmentation template and take image splicing between three key positions. We also use the positional and directional transformation of binocular virtual camera bound to user avatar to drive the transformation of stereo panorama so as to achieve real-time consistency about perspective relationship and image masking. The experimental result has shown that the algorithm in this paper is effective and feasible.
Zhang, Miao; Tong, Xiaojun
2017-07-01
This paper proposes a joint image encryption and compression scheme based on a new hyperchaotic system and curvelet transform. A new five-dimensional hyperchaotic system based on the Rabinovich system is presented. By means of the proposed hyperchaotic system, a new pseudorandom key stream generator is constructed. The algorithm adopts diffusion and confusion structure to perform encryption, which is based on the key stream generator and the proposed hyperchaotic system. The key sequence used for image encryption is relation to plain text. By means of the second generation curvelet transform, run-length coding, and Huffman coding, the image data are compressed. The joint operation of compression and encryption in a single process is performed. The security test results indicate the proposed methods have high security and good compression effect.
Adaptive Bayesian-based speck-reduction in SAR images using complex wavelet transform
Ma, Ning; Yan, Wei; Zhang, Peng
2005-10-01
In this paper, an improved adaptive speckle reduction method is presented based on dual tree complex wavelet transform (CWT). It combines the characteristics of additive noise reduction of soft thresholding with the CWT's directional selectivity, being its main contribution to adapt the effective threshold to preserve the edge detail. A Bayesian estimator is applied to the decomposed data also to estimate the best value for the noise-free complex wavelet coefficients. This estimation is based on alpha-stable and Gaussian distribution hypotheses for complex wavelet coefficients of the signal and noise, respectively. Experimental results show that the denoising performance is among the state-of-the-art techniques based on real discrete wavelet transform (DWT).
Thant, Win Win; Thein, Ni Lar
2011-01-01
In this paper we describe function tagging using Transformation Based Learning (TBL) for Myanmar that is a method of extensions to the previous statistics-based function tagger. Contextual and lexical rules (developed using TBL) were critical in achieving good results. First, we describe a method for expressing lexical relations in function tagging that statistical function tagging are currently unable to express. Function tagging is the preprocessing step to show grammatical relations of the sentences. Then we use the context free grammar technique to clarify the grammatical relations in Myanmar sentences or to output the parse trees. The grammatical relations are the functional structure of a language. They rely very much on the function tag of the tokens. We augment the grammatical relations of Myanmar sentences with transformation-based learning of function tagging.
Fast Compressed Sensing MRI Based on Complex Double-Density Dual-Tree Discrete Wavelet Transform
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Shanshan Chen
2017-01-01
Full Text Available Compressed sensing (CS has been applied to accelerate magnetic resonance imaging (MRI for many years. Due to the lack of translation invariance of the wavelet basis, undersampled MRI reconstruction based on discrete wavelet transform may result in serious artifacts. In this paper, we propose a CS-based reconstruction scheme, which combines complex double-density dual-tree discrete wavelet transform (CDDDT-DWT with fast iterative shrinkage/soft thresholding algorithm (FISTA to efficiently reduce such visual artifacts. The CDDDT-DWT has the characteristics of shift invariance, high degree, and a good directional selectivity. In addition, FISTA has an excellent convergence rate, and the design of FISTA is simple. Compared with conventional CS-based reconstruction methods, the experimental results demonstrate that this novel approach achieves higher peak signal-to-noise ratio (PSNR, larger signal-to-noise ratio (SNR, better structural similarity index (SSIM, and lower relative error.
Advantages and considerations in application of base-isolation to substation transformers
Energy Technology Data Exchange (ETDEWEB)
Saadeghvaziri, M.A. [New Jersey Inst. of Tech., Newark, NJ (United States); Allaverdi, N.H.; Feizi, B. [New Jersey Inst. of Tech., Newark, NJ (United States). Dept. of Civil Engineering; Kempner Jr, L. [Bonneville Power Administration, Portland, OR (United States)
2007-07-01
Substations are among the most important components of electrical power systems because they serve several key functions. These include providing protection to transmission and distribution lines and transfer of power between different voltage levels through the use of power transformer and reconfiguration of the power network by the opening of the transmission lines or partitioning multi-section busses. Two of the most critical elements in a substation that are vulnerable to earthquake ground motion are transformers and bushing. During past earthquakes in the United States, their performances have not been satisfactory. This paper presented seismic performance of electric substation transformers and discussed advantages and considerations in the use of base-isolation as a viable hazard mitigation option. Using an actual case study, design concepts were investigated to demonstrate that larger displacement can be accommodated. It was concluded that by highlighting important damage modes of substation transformers and bushings, the beneficial effects of base-isolation technology can be employed to mitigate seismic hazard of this type of equipment. 14 refs., 5 figs.
A NOVEL ALGORITHM OF MULTI-SENSOR IMAGE FUSION BASED ON WAVELET PACKET TRANSFORM
Institute of Scientific and Technical Information of China (English)
无
2006-01-01
In order to enhance the image information from multi-sensor and to improve the abilities of theinformation analysis and the feature extraction, this letter proposed a new fusion approach in pixel level bymeans of the Wavelet Packet Transform (WPT). The WPT is able to decompose an image into low frequencyband and high frequency band in higher scale. It offers a more precise method for image analysis than Wave-let Transform (WT). Firstly, the proposed approach employs HIS (Hue, Intensity, Saturation) transform toobtain the intensity component of CBERS (China-Brazil Earth Resource Satellite) multi-spectral image. ThenWPT transform is employed to decompose the intensity component and SPOT (Systeme Pour I'Observationde la Therre ) image into low frequency band and high frequency band in three levels. Next, two high fre-quency coefficients and low frequency coefficients of the images are combined by linear weighting strategies.Finally, the fused image is obtained with inverse WPT and inverse HIS. The results show the new approachcan fuse details of input image successfully, and thereby can obtain a more satisfactory result than that of HM(Histogram Matched)-based fusion algorithm and WT-based fusion approach.
Image Registration Using Log Polar Transform and Fft Based Scale Invariant
Directory of Open Access Journals (Sweden)
Mr. Divyang Patel,
2014-05-01
Full Text Available Image registration is the fundamental task used to match two or more partially overlapping images taken, for example, at different times, from different sensors, or from different viewpoints and stitch these images into one panoramic image comprising the whole scene. It is a fundamental image processing technique and is very useful in integrating information from different sensors, finding changes in images taken at different times, inferring three-dimensional information from stereo images, and recognizing model-based objects. Some techniques are proposed to find a geometrical transformation that relates the points of an image to their corresponding points of another image. To register two images, the coordinate transformation between a pair of images must be found. In this paper, we have proposed an algorithm that is based on Log-Polar Transform and first we roughly estimate the angle, scale and translation between two images. The proposed algorithm can recover scale value up to 5.85. The robustness of this algorithm is verified on different images with similarity transformation and in the presence of noise.
Chen, Yangkang
2016-07-01
The seislet transform has been demonstrated to have a better compression performance for seismic data compared with other well-known sparsity promoting transforms, thus it can be used to remove random noise by simply applying a thresholding operator in the seislet domain. Since the seislet transform compresses the seismic data along the local structures, the seislet thresholding can be viewed as a simple structural filtering approach. Because of the dependence on a precise local slope estimation, the seislet transform usually suffers from low compression ratio and high reconstruction error for seismic profiles that have dip conflicts. In order to remove the limitation of seislet thresholding in dealing with conflicting-dip data, I propose a dip-separated filtering strategy. In this method, I first use an adaptive empirical mode decomposition based dip filter to separate the seismic data into several dip bands (5 or 6). Next, I apply seislet thresholding to each separated dip component to remove random noise. Then I combine all the denoised components to form the final denoised data. Compared with other dip filters, the empirical mode decomposition based dip filter is data-adaptive. One only needs to specify the number of dip components to be separated. Both complicated synthetic and field data examples show superior performance of my proposed approach than the traditional alternatives. The dip-separated structural filtering is not limited to seislet thresholding, and can also be extended to all those methods that require slope information.
Directory of Open Access Journals (Sweden)
SOUMYADEEP SAMONTO
2016-03-01
Full Text Available Switchgear and Protection are the two vital terminology of Electrical power system. Normally the components of any switchgear needs better protection schemes to be set for a composite power system. Many explorers worked on artificial intelligent breaker but an indulgence of fuzzy theory is nevertheless very absent in case of buchholz relay. Here in this paper discussion has been drawn in favor of the Artificial Intelligent Buchholz (AIB relay where inputs are level of transformer oil and rate of oil rising due to over current. To fit with the transformer tank it is needed to measure level of transformer oil and the rate at which volume increasing. The constructional feature of a rate of rise pressure relay is taken into account in this work along with the working principle of a buchholz relay. The change in the inputs will give a crisp output to change the contacts state from normally closed to normally open by tripping via alarm circuit indeed like the basic buchholz relay does. The entire concept has been developed under MATLAB environment using Mamdani based Fuzzy Inference System. Experimental output data validates the implementation of Transformer Protection by Using Fuzzy Logic Based Artificial Intelligent Buchholz Relay.
Sang, Jun; Zhao, Jun; Xiang, Zhili; Cai, Bin; Xiang, Hong
2015-08-05
Gyrator transform has been widely used for image encryption recently. For gyrator transform-based image encryption, the rotation angle used in the gyrator transform is one of the secret keys. In this paper, by analyzing the properties of the gyrator transform, an improved particle swarm optimization (PSO) algorithm was proposed to search the rotation angle in a single gyrator transform. Since the gyrator transform is continuous, it is time-consuming to exhaustedly search the rotation angle, even considering the data precision in a computer. Therefore, a computational intelligence-based search may be an alternative choice. Considering the properties of severe local convergence and obvious global fluctuations of the gyrator transform, an improved PSO algorithm was proposed to be suitable for such situations. The experimental results demonstrated that the proposed improved PSO algorithm can significantly improve the efficiency of searching the rotation angle in a single gyrator transform. Since gyrator transform is the foundation of image encryption in gyrator transform domains, the research on the method of searching the rotation angle in a single gyrator transform is useful for further study on the security of such image encryption algorithms.
Directory of Open Access Journals (Sweden)
Jun Sang
2015-08-01
Full Text Available Gyrator transform has been widely used for image encryption recently. For gyrator transform-based image encryption, the rotation angle used in the gyrator transform is one of the secret keys. In this paper, by analyzing the properties of the gyrator transform, an improved particle swarm optimization (PSO algorithm was proposed to search the rotation angle in a single gyrator transform. Since the gyrator transform is continuous, it is time-consuming to exhaustedly search the rotation angle, even considering the data precision in a computer. Therefore, a computational intelligence-based search may be an alternative choice. Considering the properties of severe local convergence and obvious global fluctuations of the gyrator transform, an improved PSO algorithm was proposed to be suitable for such situations. The experimental results demonstrated that the proposed improved PSO algorithm can significantly improve the efficiency of searching the rotation angle in a single gyrator transform. Since gyrator transform is the foundation of image encryption in gyrator transform domains, the research on the method of searching the rotation angle in a single gyrator transform is useful for further study on the security of such image encryption algorithms.
A Transform-Based Feature Extraction Approach for Motor Imagery Tasks Classification
Khorshidtalab, Aida; Mesbah, Mostefa; Salami, Momoh J. E.
2015-01-01
In this paper, we present a new motor imagery classification method in the context of electroencephalography (EEG)-based brain–computer interface (BCI). This method uses a signal-dependent orthogonal transform, referred to as linear prediction singular value decomposition (LP-SVD), for feature extraction. The transform defines the mapping as the left singular vectors of the LP coefficient filter impulse response matrix. Using a logistic tree-based model classifier; the extracted features are classified into one of four motor imagery movements. The proposed approach was first benchmarked against two related state-of-the-art feature extraction approaches, namely, discrete cosine transform (DCT) and adaptive autoregressive (AAR)-based methods. By achieving an accuracy of 67.35%, the LP-SVD approach outperformed the other approaches by large margins (25% compared with DCT and 6 % compared with AAR-based methods). To further improve the discriminatory capability of the extracted features and reduce the computational complexity, we enlarged the extracted feature subset by incorporating two extra features, namely, Q- and the Hotelling’s \\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{upgreek} \\usepackage{mathrsfs} \\setlength{\\oddsidemargin}{-69pt} \\begin{document} }{}$T^{2}$ \\end{document} statistics of the transformed EEG and introduced a new EEG channel selection method. The performance of the EEG classification based on the expanded feature set and channel selection method was compared with that of a number of the state-of-the-art classification methods previously reported with the BCI IIIa competition data set. Our method came second with an average accuracy of 81.38%. PMID:27170898
DCT/DST-based transform coding for intra prediction in image/video coding.
Saxena, Ankur; Fernandes, Felix C
2013-10-01
In this paper, we present a DCT/DST based transform scheme that applies either the conventional DCT or type-7 DST for all the video-coding intra-prediction modes: vertical, horizontal, and oblique. Our approach is applicable to any block-based intra prediction scheme in a codec that employs transforms along the horizontal and vertical direction separably. Previously, Han, Saxena, and Rose showed that for the intra-predicted residuals of horizontal and vertical modes, the DST is the optimal transform with performance close to the KLT. Here, we prove that this is indeed the case for the other oblique modes. The optimal choice of using DCT or DST is based on intra-prediction modes and requires no additional signaling information or rate-distortion search. The DCT/DST scheme presented in this paper was adopted in the HEVC standardization in March 2011. Further simplifications, especially to reduce implementation complexity, which remove the mode-dependency between DCT and DST, and simply always use DST for the 4 × 4 intra luma blocks, were adopted in the HEVC standard in July 2012. Simulation results conducted for the DCT/DST algorithm are shown in the reference software for the ongoing HEVC standardization. Our results show that the DCT/DST scheme provides significant BD-rate improvement over the conventional DCT based scheme for intra prediction in video sequences.
Singleton, Robyn; Picado Araúz, María de la Paz; Trocin, Kathleen; Winskell, Kate
2017-01-01
The use of narrative has become increasingly popular in the public health, community development, and education fields. Via emotionally engaging plotlines with authentic, captivating characters, stories provide an opportunity for participants to be carried away imaginatively into the characters' world while connecting the story with their own lived experiences. Stories have been highlighted as valuable tools in transformative learning. However, little published literature exists demonstrating applications of stories in group-based transformative learning curricula. This paper describes the creation of a narrative-based transformative learning tool based on an analysis of Nicaraguan adolescents' meaning-making around intimate partner violence (IPV) in their creative narratives. In collaboration with a Nicaraguan organization, US researchers analyzed a sample of narratives ( n = 55; 16 male-authored, 39 female-authored) on IPV submitted to a 2014 scriptwriting competition by adolescents aged 15-19. The data were particularly timely in that they responded to a new law protecting victims of gender-based violence, Law 779, and contradicted social-conservative claims that the Law 779 destroys family unity. We incorporated results from this analysis into the creation of the transformative learning tool, separated into thematic sections. The tool's sections (which comprise one story and three corresponding activities) aim to facilitate critical reflection, interpersonal dialogue, and self- and collective efficacy for social action around the following themes derived from the analysis: IPV and social support; IPV and romantic love; masculinity; warning signs of IPV; and sexual abuse. As a collaboration between a public health research team based at a US university and a Nicaraguan community-based organization, it demonstrates the potential in the age of increasingly smooth electronic communication for novel community-university partnerships to facilitate the development of
Schedule Control in the Management of Waste Heat Power Projects%余热电站项目管理中的进度控制
Institute of Scientific and Technical Information of China (English)
曹良金
2016-01-01
The differences in construction and management of waste heat power projects and conventional thermal power projects are compared. Schedule management and control points in the management of waste heat power projects are mainly analyzed and summarized.%比较了余热电站与常规火力发电项目建设与管理的不同之处，着重就余热电站项目管理中进度管理及控制要点做了分析与总结。
Low-Complexity Multiple Description Coding of Video Based on 3D Block Transforms
Directory of Open Access Journals (Sweden)
Norkin Andrey
2007-01-01
Full Text Available The paper presents a multiple description (MD video coder based on three-dimensional (3D transforms. Two balanced descriptions are created from a video sequence. In the encoder, video sequence is represented in a form of coarse sequence approximation (shaper included in both descriptions and residual sequence (details which is split between two descriptions. The shaper is obtained by block-wise pruned 3D-DCT. The residual sequence is coded by 3D-DCT or hybrid, LOT+DCT, 3D-transform. The coding scheme is targeted to mobile devices. It has low computational complexity and improved robustness of transmission over unreliable networks. The coder is able to work at very low redundancies. The coding scheme is simple, yet it outperforms some MD coders based on motion-compensated prediction, especially in the low-redundancy region. The margin is up to 3 dB for reconstruction from one description.
Dong, Bing; Qin, Shun; Hu, Xinqi
2013-09-01
Large-aperture segmented primary mirror will be widely used in next-generation space-based and ground-based telescopes. The effects of intersegment gaps, obstructions, position and figure errors of segments, which are all involved in the pupil plane, on the image quality metric should be analyzed using diffractive imaging theory. Traditional Fast Fourier Transform (FFT) method is very time-consuming and costs a lot of memory especially in dealing with large pupil-sampling matrix. A Partial Fourier Transform (PFT) method is first proposed to substantially speed up the computation and reduce memory usage for diffractive imaging analysis. Diffraction effects of a 6-meter segmented mirror including 18 hexagonal segments are simulated and analyzed using PFT method. The influence of intersegment gaps and position errors of segments on Strehl ratio is quantitatively analyzed by computing the Point Spread Function (PSF). By comparing simulation results with theoretical results, the correctness and feasibility of PFT method is confirmed.
Low-Complexity Multiple Description Coding of Video Based on 3D Block Transforms
Directory of Open Access Journals (Sweden)
Andrey Norkin
2007-02-01
Full Text Available The paper presents a multiple description (MD video coder based on three-dimensional (3D transforms. Two balanced descriptions are created from a video sequence. In the encoder, video sequence is represented in a form of coarse sequence approximation (shaper included in both descriptions and residual sequence (details which is split between two descriptions. The shaper is obtained by block-wise pruned 3D-DCT. The residual sequence is coded by 3D-DCT or hybrid, LOT+DCT, 3D-transform. The coding scheme is targeted to mobile devices. It has low computational complexity and improved robustness of transmission over unreliable networks. The coder is able to work at very low redundancies. The coding scheme is simple, yet it outperforms some MD coders based on motion-compensated prediction, especially in the low-redundancy region. The margin is up to 3 dB for reconstruction from one description.
Musatenko, Yurij S.; Kurashov, Vitalij N.
1998-10-01
The paper presents improved version of our new method for compression of correlated image sets Optimal Image Coding using Karhunen-Loeve transform (OICKL). It is known that Karhunen-Loeve (KL) transform is most optimal representation for such a purpose. The approach is based on fact that every KL basis function gives maximum possible average contribution in every image and this contribution decreases most quickly among all possible bases. So, we lossy compress every KL basis function by Embedded Zerotree Wavelet (EZW) coding with essentially different loss that depends on the functions' contribution in the images. The paper presents new fast low memory consuming algorithm of KL basis construction for compression of correlated image ensembles that enable our OICKL system to work on common hardware. We also present procedure for determining of optimal losses of KL basic functions caused by compression. It uses modified EZW coder which produce whole PSNR (bitrate) curve during the only compression pass.
Phase synchronization based on a Dual-Tree Complex Wavelet Transform
Ferreira, Maria Teodora; Domingues, Margarete Oliveira; Macau, Elbert E. N.
2016-11-01
In this work, we show the applicability of our Discrete Complex Wavelet Approach (DCWA) to verify the phenomenon of phase synchronization transition in two coupled chaotic Lorenz systems. DCWA is based on the phase assignment from complex wavelet coefficients obtained by using a Dual-Tree Complex Wavelet Transform (DT-CWT). We analyzed two coupled chaotic Lorenz systems, aiming to detect the transition from non-phase synchronization to phase synchronization. In addition, we check how good is the method in detecting periods of 2π phase-slips. In all experiments, DCWA is compared with classical phase detection methods such as the ones based on arctangent and Hilbert transform showing a much better performance.
Super-resolution image restoration algorithm based on orthogonal discrete wavelet transform
Institute of Scientific and Technical Information of China (English)
Yangyang Liu(刘扬阳); Weiqi Jin(金伟其); Binghua Su(苏秉华)
2004-01-01
By using orthogonal discrete wavelet transform(ODWT)and generalized cross validation(GCV),and combining with Luck-Richardson algorithm based on Poisson-Markovmodel (MPML),several new superresolution image restoration algorithms are proposed.According to simulation experiments for practical images,all the proposed algor ithms could retain image details better than MPML,and be more suitable to low signal-to-noise ratio(SNR)images.The single operation wavelet MPML(SW-MPML)algorithm and MPML algorithm based on single operation wavelet transform(MPML-SW)avoid the iterative operation of self-adaptive parameter in MPML particularly,and improve operating speed and precision.They are instantaneous to super-resolution image restoration process and have extensive application foreground.
Intermittent Clutter Removal Approac for wind Profiler Data Based on Fractional Fourier Transform
Institute of Scientific and Technical Information of China (English)
YUAN Lei; AN Jian-ping; BU Xiang-yuan
2009-01-01
Through the analysis of the target characteristics and according to the intermittent clutter bursting and short duration characteristics, a new method for the clutter recognition based on the fractional Fourier transform (FRFT) is proposed. This method is predicated on the fact that the FRFT perfectly localizes a chirp signal as an impulse when the angle parameter of the transform matches the chirp rate of the chirp signal. The method involves detecting the presence of the intermittent clutter and correctly estimating its orientation in the time-frequency plane, removing the intermittent clutter in the fractional domain, and completing wind estimation by the power spectrum. By testing the artificial WPR-like signal and data measured from the field, we verify that the FRFT-based method is very effective.
CONSTRUCTION OF PROXY BLIND SIGNATURE SCHEME BASED ON MULTI-LINEAR TRANSFORM
Institute of Scientific and Technical Information of China (English)
Zhao Zemao; Liu Fengyu
2004-01-01
A general method of constructing proxy blind signature is proposed based on multilinear transform. Based on this method, the four proxy blind signature schemes are correspondently generated with four different signature equations, and each of them has four forms of variations of signs. Hence there are sixteen signatures in all, and all of them are proxy stronglyblind signature schemes. Furthermore, the two degenerated situations of multi-linear transform are discussed. Their corresponding proxy blind signature schemes are shown, too. But some schemes come from one of these degenerate situations are proxy weakly-blind signature scheme.The security for proposed scheme is analyzed in details. The results indicate that these signature schemes have many good properties such as unforgeability, distinguish-ability of proxy signature,non-repudiation and extensive value of application etc.
Directory of Open Access Journals (Sweden)
Chunyan Hou
2009-08-01
Full Text Available We develop an approach of component software reliability analysis which includes the benefits of both time domain, and structure based approaches. This approach overcomes the deficiency of existing NHPP techniques that fall short of addressing repair, and internal system structures simultaneously. Our solution adopts a method of transformation of testing data to cover both methods, and is expected to improve reliability prediction. This paradigm allows component-based software testing process doesn’t meet the assumption of NHPP models, and accounts for software structures by the way of modeling the testing process. According to the testing model it builds the mapping relation from the testing profile to the operational profile which enables the transformation of the testing data to build the reliability dataset required by NHPP models. At last an example is evaluated to validate and show the effectiveness of this approach.
Noise Reduction in Breath Sound Files Using Wavelet Transform Based Filter
Syahputra, M. F.; Situmeang, S. I. G.; Rahmat, R. F.; Budiarto, R.
2017-04-01
The development of science and technology in the field of healthcare increasingly provides convenience in diagnosing respiratory system problem. Recording the breath sounds is one example of these developments. Breath sounds are recorded using a digital stethoscope, and then stored in a file with sound format. This breath sounds will be analyzed by health practitioners to diagnose the symptoms of disease or illness. However, the breath sounds is not free from interference signals. Therefore, noise filter or signal interference reduction system is required so that breath sounds component which contains information signal can be clarified. In this study, we designed a filter called a wavelet transform based filter. The filter that is designed in this study is using Daubechies wavelet with four wavelet transform coefficients. Based on the testing of the ten types of breath sounds data, the data is obtained in the largest SNRdB bronchial for 74.3685 decibels.
A Transformation-based Implementation for CLP with Qualification and Proximity
Caballero, Rafael; Romero-Díaz, Carlos A
2010-01-01
Uncertainty in logic programming has been widely investigated in the last decades, leading to multiple extensions of the classical LP paradigm. However, few of these are designed as extensions of the well-established and powerful CLP scheme for Constraint Logic Programming. In a previous work we have proposed the SQCLP (proximity-based qualified constraint logic programming) scheme as a quite expressive extension of CLP with support for qualification values and proximity relations as generalizations of uncertainty values and similarity relations, respectively. In this paper we provide a transformation technique for transforming SQCLP programs and goals into semantically equivalent CLP programs and goals, and a practical Prolog-based implementation of some particularly useful instances of the SQCLP scheme. We also illustrate, by showing some simple-and working-examples, how the prototype can be effectively used as a tool for solving problems where qualification values and proximity relations play a key role. I...
FAST DISCRETE CURVELET TRANSFORM BASED ANISOTROPIC FEATURE EXTRACTION FOR IRIS RECOGNITION
Directory of Open Access Journals (Sweden)
Amol D. Rahulkar
2010-11-01
Full Text Available The feature extraction plays a very important role in iris recognition. Recent researches on multiscale analysis provide good opportunity to extract more accurate information for iris recognition. In this work, a new directional iris texture features based on 2-D Fast Discrete Curvelet Transform (FDCT is proposed. The proposed approach divides the normalized iris image into six sub-images and the curvelet transform is applied independently on each sub-image. The anisotropic feature vector for each sub-image is derived using the directional energies of the curvelet coefficients. These six feature vectors are combined to create the resultant feature vector. During recognition, the nearest neighbor classifier based on Euclidean distance has been used for authentication. The effectiveness of the proposed approach has been tested on two different databases namely UBIRIS and MMU1. Experimental results show the superiority of the proposed approach.
Ion collision cross section measurements in Fourier transform-based mass analyzers.
Li, Dayu; Tang, Yang; Xu, Wei
2016-06-01
With the increasing demands of molecular structure analysis, several methods have been developed to measure ion collision cross sections within Fourier transform (FT) based mass analyzers. Particularly in the recent three years since 2012, the method of obtaining biomolecule collision cross sections was achieved in Fourier transform ion cyclotron resonance (FT-ICR) cells. Furthermore, similar methods have been realized or proposed for orbitraps and quadrupole ion traps. This technique adds a new ion structure analysis capability to FT-based mass analyzers. By providing complementary ion structure information, it could be used together with tandem mass spectrometry and ion mobility spectroscopy techniques. Although many questions and challenges remain, this technique potentially would greatly enhance the ion structure analysis capability of a mass spectrometer, and provide a new tool for chemists and biochemists.
Cao, Guangxi; Xu, Wei
2016-02-01
This paper investigates the nonlinear structure between carbon and energy markets by employing the maximum overlap wavelet transform (MODWT) as well as the multifractal detrended cross-correlation analysis based on maximum overlap wavelet transform (MFDCCA-MODWT). Based on the MODWT multiresolution analysis and the statistic Qcc(m) significance, relatively significant cross-correlations are obtained between carbon and energy future markets either on different time scales or on the whole. The result of the Granger causality test indicates bidirectional Granger causality between carbon and electricity future markets, although the Granger causality relationship between the carbon and oil price is not evident. The existence of multifractality for the returns between carbon and energy markets is proven with the MFDCCA-MODWT algorithm. In addition, results of investigating the origin of multifractality demonstrate that both long-range correlations and fat-tailed distributions play important roles in the contributions of multifractality.
The segmentation of FMI image based on 2-D dyadic wavelet transform
Liu, Rui-Lin; Wu, Yue-Qi; Liu, Jian-Hua; Ma, Yong
2005-06-01
A key aspect in extracting quantitative information from FMI logs is to segment the FMI image to get images of pores, vugs and fractures. A segmentation method based on the dyadic wavelet transform in 2-D is introduced in this paper. The first step is to find all the edge pixels of the FMI image using the 2-D wavelet transform. The second step is to calculate a segmentation threshold based on the average value of the edge pixels. Field data processing examples show that sub-images of vugs and fractures can be correctly separated from original FMI data continuously and automatically along the depth axis. The image segmentation lays the foundation for in-situ parameter calculation.
Locke, Jonathan; White, Paul R
2011-10-01
The analysis of cetacean vocalizations is considered using Fourier-based techniques that employ chirp functions in their decomposition. In particular, the paper considers a short-time methods based on the fractional Fourier transform for detecting frequency modulated narrow-band signals, such as dolphin whistles, and compares this to the classical short-time Fourier methods. The fractional Fourier technique explored computes transforms associated with a range of chirp rates and automatically selects the rate for the final analysis. This avoids the need for prior knowledge of signal's chirp rate. An analysis is presented that details the performance of both methods as signal detectors and allows one to determine their detection thresholds. These thresholds are then used to measure the detectability of synthetic signals. This principle is then extended to measure performance on a set of recordings of narrow-band vocalizations from a range of cetacean species.
De-noising of Raman spectrum signal based on stationary wavelet transform
Institute of Scientific and Technical Information of China (English)
Qingwei Gao(高清维); Zhaoqi Sun(孙兆奇); Zhuoliang Cao(曹卓良); Pu Cheng(程蒲)
2004-01-01
@@ In this paper,the Raman spectrum signal de-noising based on stationary wavelet transform is discussed.Haar wavelet is selected to decompose the Raman spectrum signal for several levels based on stationarywavelet transform.The noise mean square σj is estimated by the wavelet details at every level,and thewavelet details toward 0 by a threshold σj √2lnn,where n is length of the detail,then recovery signalis reconstructed.Experimental results show this method not only suppresses noise effectively,but alsopreserves as many target characteristics of original signal as possible.This de-noising method offers a veryattractive alternative to Raman spectrum signal noise suppress.
Improved Real-time Denoising Method Based on Lifting Wavelet Transform
Directory of Open Access Journals (Sweden)
Liu Zhaohua
2014-06-01
Full Text Available Signal denoising can not only enhance the signal to noise ratio (SNR but also reduce the effect of noise. In order to satisfy the requirements of real-time signal denoising, an improved semisoft shrinkage real-time denoising method based on lifting wavelet transform was proposed. The moving data window technology realizes the real-time wavelet denoising, which employs wavelet transform based on lifting scheme to reduce computational complexity. Also hyperbolic threshold function and recursive threshold computing can ensure the dynamic characteristics of the system, in addition, it can improve the real-time calculating efficiency as well. The simulation results show that the semisoft shrinkage real-time denoising method has quite a good performance in comparison to the traditional methods, namely soft-thresholding and hard-thresholding. Therefore, this method can solve more practical engineering problems.
Study on New Smart Transformer Terminal Unit Based on ARM and GPRS Network
Directory of Open Access Journals (Sweden)
Na Wu
2013-12-01
Full Text Available Distribution transformer is one of the most important power equipments in distribution network, whose running state exercises a great influence on the stability of the network. Transformer Terminal Unit (TTU is an effective device to monitor the running state of transformers in the distribution automation system. In this paper, we study a new smart TTU which uses ARM7 series chip as processor, equipped with ATT7022B based electric meter module and GPRS module for remote data transmission control. We focus on the corresponding hardware, software design and the measurement principle of harmonics of TTU. The new TTU can measure the electric parameters of the distribution transformer precisely. Taking advantage of the powerful ARM processor, it can analyze harmonic of the power line effectively. Due to the always-on-line feature of GPRS, TTU can achieve reliable communication with the remote terminal and the master station. Compared with other similar units, the new unit outperforms in terms of real-time, precision and reliability, which can fully meet with the high-speed development of distribution automation system.
Directory of Open Access Journals (Sweden)
Senay Seda
2010-01-01
Full Text Available We consider the reconstruction of signals from nonuniformly spaced samples using a projection onto convex sets (POCSs implemented with the evolutionary time-frequency transform. Signals of practical interest have finite time support and are nearly band-limited, and as such can be better represented by Slepian functions than by sinc functions. The evolutionary spectral theory provides a time-frequency representation of nonstationary signals, and for deterministic signals the kernel of the evolutionary representation can be derived from a Slepian projection of the signal. The representation of low pass and band pass signals is thus efficiently done by means of the Slepian functions. Assuming the given nonuniformly spaced samples are from a signal satisfying the finite time support and the essential band-limitedness conditions with a known center frequency, imposing time and frequency limitations in the evolutionary transformation permit us to reconstruct the signal iteratively. Restricting the signal to a known finite time and frequency support, a closed convex set, the projection generated by the time-frequency transformation converges into a close approximation to the original signal. Simulation results illustrate the evolutionary Slepian-based transform in the representation and reconstruction of signals from irregularly-spaced and contiguous lost samples.
A 3.16-7 GHz transformer-based dual-band CMOS VCO
Zhu, Li; Zhigong, Wang; Zhiqun, Li; Qin, Li; Faen, Liu
2015-03-01
A dual-band, wide tuning range voltage-controlled oscillator that uses transformer-based fourth-order (LC) resonator with a compact common-centric layout is presented. Compared with the traditional wide band (VCO), it can double frequency tuning range without degrading phase noise performance. The relationship between the coupling coefficient of the transformer, selection of frequency bands, and the quality factor at each band is investigated. The transformer used in the resonator is a circular asymmetric concentric topology. Compared with conventional octagon spirals, the proposed circular asymmetric concentric transformer results in a higher quality-factor, and hence a lower oscillator phase noise. The VCO is designed and fabricated in a 0.18-μm CMOS technology and has 75% wide tuning range of 3.16-7.01 GHz. Depending on the oscillation frequency, the VCO current consumption is adjusted from 4.9 to 6.3 mA. The measured phase noises at 1 MHz offset from carrier frequencies of 3.1, 4.5, 5.1, and 6.6 GHz are -122.5, -113.3, -110.1, and -116.8 dBc/Hz, respectively. The chip area, including the pads, is 1.2 × 0.62 mm2 and the supply voltage is 1.8 V. Project supported by the National High Technology Research and Development Program of China (No. 2011AA10305) and the National Natural Science Foundation of China (No. 60901012).
Induction motor rotor fault diagnosis method based on double PQ transformation
Institute of Scientific and Technical Information of China (English)
HUANG Jin; NIU Faliang; YANG Jiaqiang
2007-01-01
This Paper presents a new rotor fault diagnosis method for induction motors which is based on the double PQ transformation.We construct the PQ transformation matrix with the positive sequence fundamental voltage components and their Hilbert transformation as elements.The active power P and the reactive power Q are obtained through the PO transformation of the stator currents.As both P and Q are constant for a healthy motor,they are represented by a dot on the PQ plane.Whereas the P and Q for a rotor broken bar motor are represented by an ellipse because they comprise an additional frequency component 2sfs (s is the slip and js is the supply frequency).Thus,by distinguishing these two different patterns.the rotor broken bar fault is detected.We use the major radius of the ellipse as the fault indicator and the distance between the point of no-load condition and the center of the ellipse on the PQ plane as its normalization value.We thus arrive at the fault severity factor which is fairly independent of the load level and the inertia value of the induction motors.Experimental results have demonstrated that the proposed method is effective in identifying the rotor-broken-bars fault and at determining the severity of the fault.
Arikan and Alamouti matrices based on fast block-wise inverse Jacket transform
Lee, Moon Ho; Khan, Md Hashem Ali; Kim, Kyeong Jin
2013-12-01
Recently, Lee and Hou (IEEE Signal Process Lett 13: 461-464, 2006) proposed one-dimensional and two-dimensional fast algorithms for block-wise inverse Jacket transforms (BIJTs). Their BIJTs are not real inverse Jacket transforms from mathematical point of view because their inverses do not satisfy the usual condition, i.e., the multiplication of a matrix with its inverse matrix is not equal to the identity matrix. Therefore, we mathematically propose a fast block-wise inverse Jacket transform of orders N = 2 k , 3 k , 5 k , and 6 k , where k is a positive integer. Based on the Kronecker product of the successive lower order Jacket matrices and the basis matrix, the fast algorithms for realizing these transforms are obtained. Due to the simple inverse and fast algorithms of Arikan polar binary and Alamouti multiple-input multiple-output (MIMO) non-binary matrices, which are obtained from BIJTs, they can be applied in areas such as 3GPP physical layer for ultra mobile broadband permutation matrices design, first-order q-ary Reed-Muller code design, diagonal channel design, diagonal subchannel decompose for interference alignment, and 4G MIMO long-term evolution Alamouti precoding design.
HMM based Offline Signature Verification system using ContourletTransform and Textural features
Directory of Open Access Journals (Sweden)
K N PUSHPALATHA
2014-07-01
Full Text Available Handwritten signatures occupy a very special place in the identification of an individual and it is a challenging task because of the possible variations in directions and shapes of the constituent strokes of written samples. In this paper we investigated offline verifications system based on fusion of contourlet transform, directional features and Hidden Markov Model (HMM as classifier. The handwritten signature image is preprocessed for noise removal and a two level contourlet transform is applied to get feature vector. The textural features are computed and concatenated with coefficients of contourlet transform to form the final feature vector. A two level contourlet transform is applied to get feature vector after the signature images of both query and database are preprocessed for noise removal. The classification results are computed using HTK tool with HMM classifier. The experimental results are computed using GPDS-960 database images to get the parameters like False Rejection Rate (FRR, False Acceptance Rate (FAR and Total Success Rate (TSR. The results show that the values of FRR and FAR are improved compared to the existing algorithm.
Multiple information encryption by user-image-based gyrator transform hologram
Abuturab, Muhammad Rafiq
2017-05-01
A novel multiple information encryption by user-image-based gyrator transform hologram is proposed. In encryption process, each channel of the user image is phase encoded, modulated by random phase function and then gyrator transformed to get the gyrator spectrum of user image. Subsequently, each channel of the secret image is normalized, phase encoded, multiplied by modulated user image, and then gyrator transformed to obtain the gyrator spectrum of secret image. The encrypted digital hologram is recorded by the interference between the gyrator spectrum of user image and the spherical wave function. Similarly, the digital hologram for decryption is recorded by the interference between the gyrator spectrum of secret image and the spherical wave function. The multiple encrypted digital holograms are multiplexed into a final encoded hologram and the corresponding digital holograms for decryption are multiplexed into a final hologram for decryption. The wavelength and radius of the spherical wave function, and angle of gyrator transform are all essential keys for decryption. The proposed system has two main features. First, the encrypted hologram has no information about secret image. Second, the hologram for decryption used as identification key. Consequently the two marked security layers of information protection are achieved. The proposal can be realized by optoelectronic system. Numerical simulation results demonstrate the feasibility and security of the proposed technique.
Study of Dielectric Breakdown Performance of Transformer Oil Based Magnetic Nanofluids
Directory of Open Access Journals (Sweden)
Yuzhen Lv
2017-07-01
Full Text Available Research on the transformer oil-based nanofluids (NFs has been raised expeditiously over the past decade. Although, there is discrepancy in the stated results and inadequate understanding of the mechanisms of improvement of dielectric nanofluids, these nanofluids have emerged as a potential substitute of mineral oils as insulating and heat removal fluids for high voltage equipment. The transformer oil (TO based magnetic fluids (ferrofluids may be regarded as the posterity insulation fluids as they propose inspiring unique prospectus to improve dielectric breakdown strength, as well as heat transfer efficiency, as compared to pure transformer oils. In this work, transformer oil-based magnetic nanofluids (MNFs are prepared by dispersal of Fe3O4 nanoparticles (MNPs into mineral oil as base oil, with various NPs loading from 5 to 80% w/v. The lightning impulse breakdown voltages (BDV measurement was conducted in accordance with IEC 60897 by using needle to sphere electrodes geometry. The test results showed that dispersion of magnetic NPs may improve the insulation strength of MO. With the increment of NPs concentrations, the positive lightning impulse (LI breakdown strength of TO is first raised, up to the highest value at 40% loading, and then tends to decrease at higher concentrations. The outcomes of negative LI breakdown showed that BDV of MNFs, with numerous loadings, were inferior to the breakdown strength of pure MO. The 40% concentration of nanoparticles (optimum concentration was selected, and positive and negative LI breakdown strength was also further studied at different sizes (10 nm, 20 nm, 30 nm and 40 nm of NPs and different electrode gap distances. Augmentation in the BDV of the ferrofluids (FFs is primarily because of dielectric and magnetic features of Fe3O4 nanoaprticles, which act as electron scavengers and decrease the rate of free electrons produced in the ionization process. Research challenges and technical difficulties
Biomedical Image Processing Using FCM Algorithm Based on the Wavelet Transform
Institute of Scientific and Technical Information of China (English)
YAN Yu-hua; WANG Hui-min; LI Shi-pu
2004-01-01
An effective processing method for biomedical images and the Fuzzy C-mean (FCM) algorithm based on the wavelet transform are investigated.By using hierarchical wavelet decomposition, an original image could be decomposed into one lower image and several detail images. The segmentation started at the lowest resolution with the FCM clustering algorithm and the texture feature extracted from various sub-bands. With the improvement of the FCM algorithm, FCM alternation frequency was decreased and the accuracy of segmentation was advanced.
Guocheng Yang; Meiling Li; Leiting Chen; Jie Yu
2015-01-01
We propose a novel medical image fusion scheme based on the statistical dependencies between coefficients in the nonsubsampled contourlet transform (NSCT) domain, in which the probability density function of the NSCT coefficients is concisely fitted using generalized Gaussian density (GGD), as well as the similarity measurement of two subbands is accurately computed by Jensen-Shannon divergence of two GGDs. To preserve more useful information from source images, the new fusion rules are devel...
Liang Xu; Junping Du; Qingping Li
2013-01-01
In the nonsubsampled contourlet transform (NSCT) domain, a novel image fusion algorithm based on the visual attention model and pulse coupled neural networks (PCNNs) is proposed. For the fusion of high-pass subbands in NSCT domain, a saliency-motivated PCNN model is proposed. The main idea is that high-pass subband coefficients are combined with their visual saliency maps as input to motivate PCNN. Coefficients with large firing times are employed as the fused high-pass subband coefficients. ...
Institute of Scientific and Technical Information of China (English)
Xiao-Hui Yang; Li-Cheng Jiao; Deng-Feng Li
2009-01-01
A directional filter algorithm for intensity synthetic aperture radar (SAR) image based on nonsubsampled contourlet transform (NSCT) and immune clonal selection (ICS) is presented. The proposed filter mainly focuses on exploiting different features of edges and noises by NSCT. Furthermore, ICS strategy is introduced to optimize threshold parameter and amplify parameter adaptively. Numerical experiments on real SAR images show that there are improvements in both visual effects and objective indexes.
Copyright protection in digital museum based on digital holography and discrete wavelet transform
Institute of Scientific and Technical Information of China (English)
Zhibin Li; Fei Xia; Gang Zheng; Junyong Zhang
2008-01-01
@@ A new method to protect the copyright of digital museum based on digital holography is proposed. The Fresnel hologram of watermark image is embedded in the object to be protected through discrete wavelet transform (DWT). After the watermark detection, the copyright information appears in the reconstructed hologram. With the higher redundancy feature in the hologram, the proposed technique can actually survive several kinds of image processing. Experimental results prove that the presented method has good robustness in image protection.
Energy Technology Data Exchange (ETDEWEB)
Busch, F. [DREWAG, Dresden (Germany); Klauke, F. [BBP ENERGY, Oberhausen (Germany)
2001-07-01
Today, Dresden is covering just under half of the total heat requirements by district heating, 95% of which come from heating and refuse incineration and heating power stations. The location of the new gas-cycle power station at the intersection of the big long-distance heating lines is near the centre of the town. The district heating power station Dresden-Nossener Bruecke was conceived for base-load operation and, thanks to its flexible design, is capable of supplying the city's networks with about 85% of its requirements of electric energy and district heating in gas and steam operation. For an adequate supply with a high rate of fuel utilization the waste-heat boilers were designed in such a way as to be usable in five different operating modes. (orig.) [German] Dresden deckt heute knapp die Haelfte des gesamten Waermebedarfs durch Fernwaerme, die zu 95% aus Heiz- und Muell-Heizkraftwerken stammt. Der Standort der neuen GuD-Anlage am Knotenpunkt der grossen Fernwaermeleitungen liegt zentrumsnah. Das Heizkraftwerk Dresden-Nossener Bruecke wurde fuer den Grundlastbetrieb konzipiert und ist dank flexibler Auslegung in der Lage, die Stadtnetze mit rund 85% ihres Elektroenergie- und Fernwaermebedarfs im GuD-Betrieb zu versorgen. Zur leistungsgerechten Versorgung mit hohem Brennstoffnutzungsgrad wurden die Abhitzekessel so ausgestattet, dass sie in fuenf verschiedenen Betriebsarten einsetzbar sind. (orig.)
Su, Yonggang; Tang, Chen; Li, Biyuan; Chen, Xia; Xu, Wenjun; Cai, Yuanxue
2017-01-20
We propose an optical color image encryption system based on the single-lens Fourier transform, the Fresnel transform, and the chaotic random phase masks (CRPMs). The proposed encryption system contains only one optical lens, which makes it more efficient and concise to implement. The introduction of the Fresnel transform makes the first phase mask of the proposed system also act as the main secret key when the input image is a non-negative amplitude-only map. The two CRPMs generated by dual two-dimensional chaotic maps can provide more security to the proposed system. In the proposed system, the key management is more convenient and the transmission volume is reduced greatly. In addition, the secret keys can be updated conveniently in each encryption process to invalidate the chosen plaintext attack and the known plaintext attack. Numerical simulation results have demonstrated the feasibility and security of the proposed encryption system.
Attenuation compensation of GPR signal based on generalized S-transform
Hu, Shufan; Zhao, Yonghui; Qin, Tan; An, Cong
2017-04-01
Ground penetrating radar (GPR), as a nondestructive technique, has been widely used in civil engineering. Due to the complexity of the engineering conditions and attenuation of the GPR signal with depth, the radargram contained deep information usually shows a low resolution and S/N ratio. It might be one of the most difficult problems to GPR data interpretation, which limits the further application of the GPR method in civil engineering. The traditional way, such as a manual or automatic gain technique, was commonly used to enhance the weak GPR signal of deep target. However, due to the non-stationary of GPR signal, only the energy compensation in time or frequency domain may be not appropriate while using the manual or automatic gain methods. In this sense, neither the automatic gain compensation nor the other gain method seem likely difficult to obtain better results. In fact, it's not reasonable to separate the information in time and frequency domain from GPR data. The S-transform is a time-frequency analysis technique, which makes it possible for analyzing the GPR signal in time and frequency domain simultaneously. In addition, use S-transform to GPR data can preserve the original information in a wide frequency range. Here, we proposed a generalized S-transform based on exponential function and used it to the attenuation compensation of GPR signal. Firstly, the GPR data were transform to time-frequency domain using generalized S-transform trace by trace. Then the high-frequency component will be weighted at each time sample according to the attenuation ratio of low-frequency component. In this way the spectrum difference of each frequency component between late and early sampling time have the same ratio factor, which greatly compensates the attenuation of high-frequency component. Finally, the well compensated GPR data were obtained by inverse S-transform. Synthetic and real GPR data were used to verify the effectiveness and robustness of the proposed
Watermarking algorithm based on Her transform%Her变换的数字水印算法
Institute of Scientific and Technical Information of China (English)
王立鹏
2012-01-01
Most transformations used for digital watermarking in transformation domain are orthogonal transformations, such as DCT and DWT. Three types of orthogonal transformation with excellent performance are found by studying three systems of orthogonal functions： Haar function system, Haar type function system and Walsh function system. Her transformation is one of the three transformations. Her function system can not be used directly in digital watermarking as DCT matrix being used, since Her matrix of Her function system is not normalized orthogonal matrix. The corresponding discrete matrix is obtained by sampling Her continuous functions, and successfully used in digital watermarking with a series of experiments and theoretical analysis. A digital watermarking algorithm based on Her transformation is proposed. Experimental results show that the algorithm is simple and good at perceptual transparency as well as robustness of watermarking extraction. In addition, the experimental results of comparing with the traditional DCT watermarking show that this algorithm is of good robustness against noise and filtering.%经对目前数字水印变换域算法的研究，发现常用的变换大多都是正交变换（如DCT和DwT等）。作者通过对Haar函数系、Haar类函数系和Walsh函数系这三大类正交函数系的研究，找到了与之对应的三类性能优良的正交变换，Her类正交变换就是其中的一种。由于Her函数系所对应的Her矩阵不是归一化的正交矩阵，所以不能像DCT等矩阵一样直接应用于数字水印技术，通过对Her连续函数的采样，得出了其对应的离散矩阵，然后通过一系列的实验数据和理论证明，成功的将其应用于数字水印中。最后，提出一种新颖的、鲁棒的Her域盲水印算法。实验结果表明该算法计算简单，且具有良好的不可见性，通过与传统DCT水印的对比表明，该算法在抵抗噪声和和滤波等方面具有较强的鲁棒性。
State transformation-based dynamic visual servoing for an unmanned aerial vehicle
Xie, Hui; Lynch, Alan F.
2016-05-01
In this paper, we propose a visual servoing control for a quadrotor unmanned aerial vehicle (UAV) which is based on a state transformation technique. The UAV is equipped with a single downwards facing camera, and the motion control objective is the regulation of relative displacement and yaw to a stationary visual target located on the ground. The state transformation is defined by a system of partial differential equations (PDEs) which eliminate roll and pitch rate dependence in the transformed image feature kinematics. A method for computing the general solutions of these PDEs is given, and we show a particular solution reduces to an established virtual camera approach. We treat point and line cases and introduce image moment features defined in the virtual camera image plane. Robustness of the control design is improved by accounting for attitude measurement bias, and uncertainty in thrust gain, mass, and image feature depth. The asymptotic stability of the closed-loop is proven. The method is based on a simple proportional-integral-derivative (PID) structure which can be readily implemented on-board. Experimental results show improved performance relative to previous work.
Directory of Open Access Journals (Sweden)
Fengrong Bi
2016-01-01
Full Text Available In spark ignition engines, knock onset limits the maximum spark advance. An inaccurate identification of this limit penalises the fuel conversion efficiency. Thus knock feature extraction is the key of closed-loop control of ignition in spark ignition engine. This paper reports an investigation of knock detection in spark ignition (SI engines using CEEMD-Hilbert transform based on the engine cylinder pressure signals and engine cylinder block vibration signals. Complementary Ensemble Empirical Mode Decomposition (CEEMD was used to decompose the signal and detect knock characteristic. Hilbert transform was used to analyze the frequency information of knock characteristic. The result shows that, for both of cylinder pressure signals and vibration signals, the CEEMD algorithm could extract the knock characteristic, and the Hilbert transform result shows that the energy of knock impact areas has the phenomenon of frequency concentration in both cylinder pressure signal and cylinder block vibration signal. At last, the knock window is then determined, based on which a new knock intensity evaluation factor K is propose, and it can accurately distinguish between heavy knock, light knock, and normal combustion three states.
A NEW METHOD OF BAD POINTS ELIMINATION BASED ON HOUGH TRANSFORM
Institute of Scientific and Technical Information of China (English)
Chen Su; Lin Jiayu
2010-01-01
In experimental tests,besides data in range of allowable error,the experimenters usually get some unexpected wrong data called bad points. In usual experimental data processing,the method of bad points exclusion based on automatic programming is seldom taken into consideration by researchers. This paper presents a new method to reject bad points based on Hough transform,which is modified to save computational and memory consumptions. It is fit for linear data processing and can be extended to process data that is possible to be transformed into and from linear form; curved lines,which can be effectively detected by Hough transform. In this paper,the premise is the distribution of data,such as linear distribution and exponential distribution,is predetermined. Steps of the algorithm start from searching for an approximate curve line that minimizes the sum of parameters of data points. The data points,whose parameters are above a self-adapting threshold,will be deleted. Simulation experiments have manifested that the method proposed in this paper performs efficiently and robustly.
A Wavelet-based Fast Discrimination of Transformer Magnetizing Inrush Current
Kitayama, Masashi
Recently customers who need electricity of higher quality have been installing co-generation facilities. They can avoid voltage sags and other distribution system related disturbances by supplying electricity to important load from their generators. For another example, FRIENDS, highly reliable distribution system using semiconductor switches or storage devices based on power electronics technology, is proposed. These examples illustrates that the request for high reliability in distribution system is increasing. In order to realize these systems, fast relaying algorithms are indispensable. The author proposes a new method of detecting magnetizing inrush current using discrete wavelet transform (DWT). DWT provides the function of detecting discontinuity of current waveform. Inrush current occurs when transformer core becomes saturated. The proposed method detects spikes of DWT components derived from the discontinuity of the current waveform at both the beginning and the end of inrush current. Wavelet thresholding, one of the wavelet-based statistical modeling, was applied to detect the DWT component spikes. The proposed method is verified using experimental data using single-phase transformer and the proposed method is proved to be effective.
Series transformer based diode-bridge-type solid state fault current limiter
Institute of Scientific and Technical Information of China (English)
Amir HEIDARY; Hamid RADMANESH; Seyed Hamid FATHI; G B GHAREHPETIAN
2015-01-01
We propose a novel series transformer based diode-bridge-type solid state fault current limiter (SSFCL). To control the fault current, a series RLC branch is connected to the secondary side of an isolation series transformer. Based on this RLC branch, two current limiting modes are created. In the first mode, R and C are bypassed via a paralleled power electronic switch (insulated-gate bipolar transistor, IGBT) and L remains connected to the secondary side of the transformer as a DC reactor. In the second mode, the series reactor impedance is not enough to limit the fault current. In this case, the fault current can be con-trolled by selecting a proper on-off duration of the parallel IGBT, across the series damping resistor (R) and capacitor, which inserts high impedance into the line to limit the fault current. Then, by controlling the magnitude of the DC reactor current, the fault current is reduced and the voltage of the point of common coupling (PCC) is kept at an acceptable level. In addition, in the new SSFCL, the series RC branch, connected in parallel with the IGBT, serves as a snubber circuit for decreasing the transient recovery voltage (TRV) of the IGBT during on-off states. Therefore, the power quality indices can be improved. The measure-ment results of a built prototype are presented to support the simulation and theoretical studies. The proposed SSFCL can limit the fault current without any delay and successfully smooth the fault current waveform.
Atmospheric pressure plasma jet with high-voltage power supply based on piezoelectric transformer.
Babij, Michał; Kowalski, Zbigniew W; Nitsch, Karol; Silberring, Jerzy; Gotszalk, Teodor
2014-05-01
The dielectric barrier discharge plasma jet, an example of the nonthermal atmospheric pressure plasma jet (APPJ), generates low-temperature plasmas that are suitable for the atomization of volatile species and can also be served as an ionization source for ambient mass and ion mobility spectrometry. A new design of APPJ for mass spectrometry has been built in our group. In these plasma sources magnetic transformers (MTs) and inductors are typically used in power supplies but they present several drawbacks that are even more evident when dealing with high-voltage normally used in APPJs. To overcome these disadvantages, high frequency generators with the absence of MT are proposed in the literature. However, in the case of miniaturized APPJs these conventional power converters, built of ferromagnetic cores and inductors or by means of LC resonant tank circuits, are not so useful as piezoelectric transformer (PT) based power converters due to bulky components and small efficiency. We made and examined a novel atmospheric pressure plasma jet with PT supplier served as ionization source for ambient mass spectrometry, and especially mobile spectrometry where miniaturization, integration of components, and clean plasma are required. The objective of this paper is to describe the concept, design, and implementation of this miniaturized piezoelectric transformer-based atmospheric pressure plasma jet.
Yamamoto, Takashi; Noma, Yukio; Yasuhara, Akio; Sakai, Shin-ichi
2003-10-31
We present the first study on the analytical methods of phenyltin compounds (PTs) in polychlorinated biphenyl (PCB)-based transformer oil samples. Tetraphenyltin (TePhT) has been used as stabilizer for some kinds of PCBs-based transformer oil formulations. Monophenyltin (MPhT), diphenyltin (DPhT) and triphenyltin (TrPhT) could have been formed from TePhT during long-term use. TePhT was directly measured by gas chromatograph (GC) connected with three types of detectors, a mass spectrometer (MS), a flame photometric detector (FPD) and an atomic emission detector (AED) after dilution with hexane. MPhT, DPhT and TrPhT were propylated with Grignard reagent before measurement. The MS was the most sensitive of the detectors, with detection limits of phenyltin compounds of 30 ng/ml (MPhT), 9.8 ng/ml (DPhT), 5.5 ng/ml (TrPhT) and 0.60 ng/ml (TePhT), respectively. From the viewpoint of selectivity, MS was slightly worse than other detectors, but interference from PCBs matrices was not significant under ordinary analytical conditions. Two used transformer oil samples were analyzed using the analytical methods developed in this study. TePhT and TrPhT were found in both samples.
Edge detection based on object tree image representation and wavelet transform
Institute of Scientific and Technical Information of China (English)
屈彦呈; 王常虹; 庄显义
2003-01-01
In applications such as image retrieval and recognition, precise edge detection for interested regions plays a decisive role. Existing methods generally take little care about local characteristics, or become time-consuming if every detail is considered. In the paper, a new method is put forward based on the combination of effective image representation and multiscale wavelet analysis. A new object tree image representation is introduced. Then a series of object trees are constructed based on wavelet transform modulus maxima at different scales in descending order. Computation is only needed for interested regions. Implementation steps are also given with an illustrative example.
Rapid Prototyping of Field Programmable Gate Array-Based Discrete Cosine Transform Approximations
Directory of Open Access Journals (Sweden)
Trevor W. Fox
2003-05-01
Full Text Available A method for the rapid design of field programmable gate array (FPGA-based discrete cosine transform (DCT approximations is presented that can be used to control the coding gain, mean square error (MSE, quantization noise, hardware cost, and power consumption by optimizing the coefficient values and datapath wordlengths. Previous DCT design methods can only control the quality of the DCT approximation and estimates of the hardware cost by optimizing the coefficient values. It is shown that it is possible to rapidly prototype FPGA-based DCT approximations with near optimal coding gains that satisfy the MSE, hardware cost, quantization noise, and power consumption specifications.
Double-image encryption based on joint transform correlation and phase-shifting interferometry
Institute of Scientific and Technical Information of China (English)
Lina Shen; Jun Li; Hongsen Chang
2007-01-01
An image encryption method combining the joint transform correlator (JTC) architecture with phaseshifting interferometry to realize double random-phase encoding is proposed. The encrypted field and the decrypting key are registered as holograms by phase-shifting interferometry. This method can encrypt two images simultaneously to improve the encryption efficiency of the methods based on JTC architecture, and eliminate the system alignment constraint of the methods based on Mach-Zehnder interferometer (MZI)architecture. Its feasibility and validity are verified by computer simulations. Moreover, image encryption and decryption can be achieved at high speed optically or digitally. The encrypted data are suitable for Internet transmission.
Lutsyshyn, Yaroslav
2016-01-01
We developed a CUDA-based parallelization of the annealing method for the inverse Laplace transform problem. The algorithm is based on annealing algorithm and minimizes residue of the reconstruction of the spectral function. We introduce local updates which preserve first two sum rules and allow an efficient parallel CUDA implementation. Annealing is performed with the Monte Carlo method on a population of Markov walkers. We propose imprinted branching method to improve further the convergence of the anneal. The algorithm is tested on truncated double-peak Lorentzian spectrum with examples of how the error in the input data affects the reconstruction.
Rapid Prototyping of Field Programmable Gate Array-Based Discrete Cosine Transform Approximations
Fox, Trevor W.; Turner, Laurence E.
2003-12-01
A method for the rapid design of field programmable gate array (FPGA)-based discrete cosine transform (DCT) approximations is presented that can be used to control the coding gain, mean square error (MSE), quantization noise, hardware cost, and power consumption by optimizing the coefficient values and datapath wordlengths. Previous DCT design methods can only control the quality of the DCT approximation and estimates of the hardware cost by optimizing the coefficient values. It is shown that it is possible to rapidly prototype FPGA-based DCT approximations with near optimal coding gains that satisfy the MSE, hardware cost, quantization noise, and power consumption specifications.
3D Modeling of Transformer Substation Based on Mapping and 2D Images
Directory of Open Access Journals (Sweden)
Lei Sun
2016-01-01
Full Text Available A new method for building 3D models of transformer substation based on mapping and 2D images is proposed in this paper. This method segments objects of equipment in 2D images by using k-means algorithm in determining the cluster centers dynamically to segment different shapes and then extracts feature parameters from the divided objects by using FFT and retrieves the similar objects from 3D databases and then builds 3D models by computing the mapping data. The method proposed in this paper can avoid the complex data collection and big workload by using 3D laser scanner. The example analysis shows the method can build coarse 3D models efficiently which can meet the requirements for hazardous area classification and constructions representations of transformer substation.
Sun, Zhiwei; Zhi, Ya'nan; Liu, Liren; Sun, Jianfeng; Zhou, Yu; Hou, Peipei
2013-09-01
The synthetic aperture imaging ladar (SAIL) systems typically generate large amounts of data difficult to compress with digital method. This paper presents an optical SAIL processor based on compensation of quadratic phase of echo in azimuth direction and two dimensional Fourier transform. The optical processor mainly consists of one phase-only liquid crystal spatial modulator(LCSLM) to load the phase data of target echo and one cylindrical lens to compensate the quadratic phase and one spherical lens to fulfill the task of two dimensional Fourier transform. We show the imaging processing result of practical target echo obtained by a synthetic aperture imaging ladar demonstrator. The optical processor is compact and lightweight and could provide inherent parallel and the speed-of-light computing capability, it has a promising application future especially in onboard and satellite borne SAIL systems.
Image Sequence Fusion and Denoising Based on 3D Shearlet Transform
Directory of Open Access Journals (Sweden)
Liang Xu
2014-01-01
Full Text Available We propose a novel algorithm for image sequence fusion and denoising simultaneously in 3D shearlet transform domain. In general, the most existing image fusion methods only consider combining the important information of source images and do not deal with the artifacts. If source images contain noises, the noises may be also transferred into the fusion image together with useful pixels. In 3D shearlet transform domain, we propose that the recursive filter is first performed on the high-pass subbands to obtain the denoised high-pass coefficients. The high-pass subbands are then combined to employ the fusion rule of the selecting maximum based on 3D pulse coupled neural network (PCNN, and the low-pass subband is fused to use the fusion rule of the weighted sum. Experimental results demonstrate that the proposed algorithm yields the encouraging effects.
Post, Andrew; Kurc, Tahsin; Overcash, Marc; Cantrell, Dedra; Morris, Tim; Eckerson, Kristi; Tsui, Circe; Willey, Terry; Quyyumi, Arshed; Eapen, Danny; Umpierrez, Guillermo; Ziemer, David; Saltz, Joel
2011-01-01
In the CTSA era there is great interest in aggregating and comparing populations across institutions. These sites likely represent data differently in their clinical data warehouses and other databases. Clinical data warehouses frequently are structured in a generalized way that supports many constituencies. For research, there is a need to transform these heterogeneous data into a shared representation, and to perform categorization and interpretation to optimize the data representation for investigators. We are addressing this need by extending an existing temporal abstraction-based clinical database query system, PROTEMPA. The extended system allows specifying data types of interest in federated databases, extracting the data into a shared representation, transforming it through categorization and interpretation, and loading it into a registry database that can be refreshed. Such a registry's access control, data representation and query tools can be tailored to the needs of research while keeping local databases as the source of truth.
a Simplified Parameter Design Method for Transformation Optics-Based Metamaterial Innovative Cloak
Li, Ting-Hua; Huang, Ming; Yang, Jing-Jing; Lu, Jin; Cao, Hui-Lu
2013-10-01
Transformation optics-based innovative cloak which combines the virtues of both internal and external cloaks to enable arbitrary multi-objects hidden with visions and movements was first proposed by Huang et al. [Appl. Phys. Lett.101, 151901 (2012)]. But it is rather difficult to implement in practice, for the required material parameters vary with radius and even have singular values. To accelerate its practical realization but still keep good performance of invisibility, a simplified innovative cloak with only spatially varying axial parameter is developed via choosing appropriate transformation function. The advantage of such a cloak is that both radial and azimuthal parameters are constants, and all three components are nonsingular and finite. Full-wave simulation confirms the perfect cloaking effect of the cloak. Besides, the influences of metamaterials loss and parameter deviation on the performance of cloak are also investigated. This work provides a simple and feasible solution to push metamaterial-assisted innovative cloak more closely to the practice.
Research of Adaptive Resolution Spectrum Sensing Method Based on Discrete Wavelet Packet Transform
Directory of Open Access Journals (Sweden)
Wei Naiqi
2013-09-01
Full Text Available Spectrum sensing is the precondition of the realization of cognitive radio. In order to achieve efficient multi-resolution spectrum sensing, and find the available spectrum hole quickly, it proposes a variable resolution adaptive frequency spectrum energy sensing method based on discrete wavelet packet transform (DWPT. The method applied hierarchical decomposition and threshold denoising characteristic of wavelet packet transform, and solved the problem of subband sort disorder in wavelet packet decomposition process; it can eliminate the influence of uncertainty noise on detection performance, effectively. It also can reduce the computational complexity according to demand of selection resolution and perception band. The simulation results and its analysis show that the proposed method has advantages of high precision, simple arithmetic and fine flexibility, etc. The method is adapted to fast sensing in the cognitive radio environment.
Three-dimensional beam propagation method based on the variable transformed Galerkin's method
Institute of Scientific and Technical Information of China (English)
XIAO Jinbiao; SUN Xiaohan; ZHANG Mingde
2004-01-01
A novel three-dimensional beam propagation method (BPM) based on the variable transformed Galerkin's method is introduced for simulating optical field propagation in three-dimensional dielectric structures. The infinite Cartesian x-y plane is mapped into a unit square by a tangent-type function transformation. Consequently, the infinite region problem is converted into the finite region problem. Thus, the boundary truncation is eliminated and the calculation accuracy is promoted. The three-dimensional BPM basic equation is reduced to a set of first-order ordinary differential equations through sinusoidal basis function, which fits arbitrary cladding optical waveguide, then direct solution of the resulting equations by means of the Runge-Kutta method. In addition,the calculation is efficient due to the small matrix derived from the present technique.Both z-invariant and z-variant examples are considered to test both the accuracy and utility of this approach.
Lahmiri, Salim; Gargour, Christian S; Gabrea, Marcel
2014-10-01
An automated diagnosis system that uses complex continuous wavelet transform (CWT) to process retina digital images and support vector machines (SVMs) for classification purposes is presented. In particular, each retina image is transformed into two one-dimensional signals by concatenating image rows and columns separately. The mathematical norm of phase angles found in each one-dimensional signal at each level of CWT decomposition are relied on to characterise the texture of normal images against abnormal images affected by exudates, drusen and microaneurysms. The leave-one-out cross-validation method was adopted to conduct experiments and the results from the SVM show that the proposed approach gives better results than those obtained by other methods based on the correct classification rate, sensitivity and specificity.
Improved decryption quality and security of a joint transform correlator-based encryption system
Vilardy, Juan M.; Millán, María S.; Pérez-Cabré, Elisabet
2013-02-01
Some image encryption systems based on modified double random phase encoding and joint transform correlator architecture produce low quality decrypted images and are vulnerable to a variety of attacks. In this work, we analyse the algorithm of some reported methods that optically implement the double random phase encryption in a joint transform correlator. We show that it is possible to significantly improve the quality of the decrypted image by introducing a simple nonlinear operation in the encrypted function that contains the joint power spectrum. This nonlinearity also makes the system more resistant to chosen-plaintext attacks. We additionally explore the system resistance against this type of attack when a variety of probability density functions are used to generate the two random phase masks of the encryption-decryption process. Numerical results are presented and discussed.
Directory of Open Access Journals (Sweden)
Ji Ming
2008-03-01
Full Text Available We present results of a study into the performance of a variety of different image transform-based feature types for speaker-independent visual speech recognition of isolated digits. This includes the first reported use of features extracted using a discrete curvelet transform. The study will show a comparison of some methods for selecting features of each feature type and show the relative benefits of both static and dynamic visual features. The performance of the features will be tested on both clean video data and also video data corrupted in a variety of ways to assess each feature type's robustness to potential real-world conditions. One of the test conditions involves a novel form of video corruption we call jitter which simulates camera and/or head movement during recording.
Melchert, O; Roth, B
2016-01-01
We discuss efficient algorithms for the accurate forward and reverse evaluation of the discrete Fourier-Bessel transform (dFBT) as numerical tools to assist in the 2D polar convolution of two radially symmetric functions, relevant, e.g., to applications in computational biophotonics. In our survey of the numerical procedure we account for the circumstance that the objective function might result from a more complex measurement process and is, in the worst case, known on a finite sequence of coordinate values, only. We contrast the performance of the resulting algorithms with a procedure based on a straight forward numerical quadrature of the underlying integral transform and asses its efficienty for two benchmark Fourier-Bessel pairs. An application to the problem of finite-size beam-shape convolution in polar coordinates, relevant in the context of tissue optics and optoacoustics, is used to illustrate the versatility and computational efficiency of the numerical procedure.
CHARACTERISTICS OF STRESS-INDUCED TRANSFORMATION AND MICROSTRUCTURE EVOLUTION IN Cu-BASED SMA
Institute of Scientific and Technical Information of China (English)
Cheng Peng; Xingyao Wang; Yongzhong Huo
2008-01-01
The mechanical behavior of shape memory alloys (SMAs) is closely related to the formation and evolution of its microstructures. Through theoretical analysis and experimental ob-servations, it was found that the stress-induced martensitic transformation process of single crys-tal Cu-based SMA under uniaxial tension condition consisted of three periods: nucleation, mixed nucleation and growth, and merging due to growth. During the nucleation, the stress dropped rapidly and the number of interfaces increased very fast while the phase fraction increased slowly.In the second period, both the stress and the interface number changed slightly but the phase fraction increased dramatically. Finally, the stress and the phase fraction changed slowly while the number of interfaces decreased quickly. Moreover, it was found that the transformation could be of multi-stage: sharp stress drops at several strains and correspondingly, the nucleation and growth process occurred quasi-independently in several parts of the sample.
A DNA Structure-Based Bionic Wavelet Transform and Its Application to DNA Sequence Analysis
Directory of Open Access Journals (Sweden)
Fei Chen
2003-01-01
Full Text Available DNA sequence analysis is of great significance for increasing our understanding of genomic functions. An important task facing us is the exploration of hidden structural information stored in the DNA sequence. This paper introduces a DNA structure-based adaptive wavelet transform (WT – the bionic wavelet transform (BWT – for DNA sequence analysis. The symbolic DNA sequence can be separated into four channels of indicator sequences. An adaptive symbol-to-number mapping, determined from the structural feature of the DNA sequence, was introduced into WT. It can adjust the weight value of each channel to maximise the useful energy distribution of the whole BWT output. The performance of the proposed BWT was examined by analysing synthetic and real DNA sequences. Results show that BWT performs better than traditional WT in presenting greater energy distribution. This new BWT method should be useful for the detection of the latent structural features in future DNA sequence analysis.
Control Strategy Based on Wavelet Transform and Neural Network for Hybrid Power System
Directory of Open Access Journals (Sweden)
Y. D. Song
2013-01-01
Full Text Available This paper deals with an energy management of a hybrid power generation system. The proposed control strategy for the energy management is based on the combination of wavelet transform and neural network arithmetic. The hybrid system in this paper consists of an emulated wind turbine generator, PV panels, DC and AC loads, lithium ion battery, and super capacitor, which are all connected on a DC bus with unified DC voltage. The control strategy is responsible for compensating the difference between the generated power from the wind and solar generators and the demanded power by the loads. Wavelet transform decomposes the power difference into smoothed component and fast fluctuated component. In consideration of battery protection, the neural network is introduced to calculate the reference power of battery. Super capacitor (SC is controlled to regulate the DC bus voltage. The model of the hybrid system is developed in detail under Matlab/Simulink software environment.
Temperature Dependence of Particle Size Distribution in Transformer Oil-Based Ferrofluid
Józefczak, Arkadiusz; Hornowski, Tomasz; Skumiel, Andrzej
2011-04-01
The temperature dependence of the particle size distribution (PSD) of a transformer oil-based ferrofluid was studied using an ultrasound method. The measurements of the ultrasound velocity and attenuation were carried out in the absence of an external magnetic field as a function of the volume concentration of magnetite particles at temperatures ranging from 10 °C to 80 °C. The experimental results of ultrasound measurements were analyzed within the framework of the Vinogradov-Isakovich theory which takes into account contributions to acoustical parameters due to friction and heat exchange between magnetic particles and the surrounding carrier liquid. From the best fit of the experimental results and theoretical predictions, the parameters characterizing the PSD at different temperatures were determined. In order to analyze ultrasonic data, the density and viscosity of ferrofluid samples and the transformer oil were also measured.
Distributed edge detection algorithm based on wavelet transform for wireless video sensor network
Li, Qiulin; Hao, Qun; Song, Yong; Wang, Dongsheng
2011-05-01
Edge detection algorithms are critical to image processing and computer vision. Traditional edge detection algorithms are not suitable for wireless video sensor network (WVSN) in which the nodes are with in limited calculation capability and resources. In this paper, a distributed edge detection algorithm based on wavelet transform designed for WVSN is proposed. Wavelet transform decompose the image into several parts, then the parts are assigned to different nodes through wireless network separately. Each node performs sub-image edge detecting algorithm correspondingly, all the results are sent to sink node, Fusing and Synthesis which include image binary and edge connect are executed in it. And finally output the edge image. Lifting scheme and parallel distributed algorithm are adopted to improve the efficiency, simultaneously, decrease the computational complexity. Experimental results show that this method could achieve higher efficiency and better result.
Multiple-image encryption based on phase mask multiplexing in fractional Fourier transform domain.
Liansheng, Sui; Meiting, Xin; Ailing, Tian
2013-06-01
A multiple-image encryption scheme is proposed based on the phase retrieval process and phase mask multiplexing in the fractional Fourier transform domain. First, each original gray-scale image is encoded into a phase only function by using the proposed phase retrieval process. Second, all the obtained phase functions are modulated into an interim, which is encrypted into the final ciphertext by using the fractional Fourier transform. From a plaintext image, a group of phase masks is generated in the encryption process. The corresponding decrypted image can be recovered from the ciphertext only with the correct phase mask group in the decryption process. Simulation results show that the proposed phase retrieval process has high convergence speed, and the encryption algorithm can avoid cross-talk; in addition, its encrypted capacity is considerably enhanced.
Hu, Yong; Peng, Silong; Bi, Yiming; Tang, Liang
2012-12-21
A traditional multivariate calibration transfer method such as piecewise direct standardization (PDS) is usually applied to quantitative analysis. To make the method apply to qualitative analysis of Fourier Transform Infrared spectroscopy (FTIR), we propose an improved calibration transfer method based on the maximum margin criterion (CTMMC). The new method not only considers the spectral changes under different conditions, but also takes into account the geometric characteristics of spectra from different classes, so the transformed spectra from different classes will be separated as far as possible, and this will improve the performance of the follow-up qualitative analysis. A comparative study is provided between the proposed method CTMMC and other traditional calibration transfer methods on two data sets. Experimental results show that the proposed method can achieve better performance than previous methods.
Institute of Scientific and Technical Information of China (English)
Duan Chendong; He Zhengjia; Jiang Hongkai
2004-01-01
A new time-domain analysis method that uses second generation wavelet transform (SGWT) for weak fault feature extraction is proposed. To extract incipient fault feature, a biorthogonal wavelet with the characteristics of impact is constructed by using SGWT. Processing detail signal of SGWT with a sliding window devised on the basis of rotating operation cycle, and extracting modulus maximum from each window, fault features in time-domain are highlighted. To make further analysis on the reason of the fault, wavelet package transform based on SGWT is used to process vibration data again. Calculating the energy of each frequency-band, the energy distribution features of the signal are attained. Then taking account of the fault features and the energy distribution, the reason of the fault is worked out. An early impact-rub fault caused by axis misalignment and rotor imbalance is successfully detected by using this method in an oil refinery.
Institute of Scientific and Technical Information of China (English)
无
2007-01-01
The mismatch between echo and replica caused by underwater moving target(UMT)'s radial velocity degrades the detection performance of the matched filter(MF) for the linear frequency modulation(LFM) signal. By using the focusing property of fractional Fourier transform(FRFT) to that signal, a detection algorithm for UMT's LFM echo based on the discrete fractional Fourier transform(DFRFT) is proposed. This algorithm is less affected by the target's radial velocity compared with the other MF detection algorithm utilizing zero radial velocity replica(ZRVR), and the mathematical relation between the output peak positions of these two algorithms exists in the case of existence of target echo. The algorithm can also estimate the target distance by using this relation. The simulation and experiment show that this algorithm's detection performance is better than or equivalent to that of the other MF algorithm utilizing ZRVR for the LFM echo of UMT with unknown radial velocity under reverberation noise background.
Xue, Min; Pan, Shilong; Zhao, Yongjiu
2016-07-01
A large dynamic range optical vector analyzer (OVA) based on optical single-sideband modulation is proposed and demonstrated. By dividing the optical signal after optical device under test into two paths, reversing the phase of one swept sideband using a Hilbert transformer in one path, and detecting the two signals from the two paths with a balanced photodetector, the measurement errors induced by the residual -1st-order sideband and the high-order sidebands can be eliminated and the dynamic range of the measurement is increased. In a proof-of-concept experiment, the stimulated Brillouin scattering and a fiber Bragg grating are measured by OVAs with and without the Hilbert transform and balanced photodetection. Results show that about 40-dB improvement in the measurement dynamic range is realized by the proposed OVA.
A Compensation Algorithm Based on RSPWVD-Hough Transform for Doppler Expansion in Passive Radar
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Guan Xin
2013-12-01
Full Text Available For passive radar, long integration time is used to achieve high processing gain to detect weak target. But range migration and Doppler expansion may occur for high-speed targets. Keystone transform can be used to rectify range migration introduced by radial-speed. But tangential-speed may still lead to Doppler expansion, which entails a loss of integration gain. In this paper, signal model is presented to analyze the reason for Doppler expansion. Then, a Doppler expansion compensation method is introduced based on RSPWVD-Hough transform for multi-target scenario. Simulation results show that the proposed method can compensate the energy loss caused by Doppler expansion for multi-target scene, and it achieves good performance. The proposed method is also effective for weak targets, which means it can improve the detection ability of weak target in passive radar systems.
Fault Diagnosis in Transformer Based on Weighted Degree of Grey Slope Incidence of Optimized Entropy
Directory of Open Access Journals (Sweden)
Zhang Anping
2016-01-01
Full Text Available Dissolved gas analysis (DGA is an important method to find the hidden or incipient insulation faults of oil-immersed power transformer. However, code deficiency exists in the gas ratio methods specified by the IEC standard and complexity of fault diagnosis for power transformer. Hence a new model based on optimized weighted degree of grey slope incidence was put forward. Firstly, the entropy weight is used to determine objective weight of indices; then the model fault types are obtained by weighted degree of grey slope incidence. The combination of entropy weight with grey slope incidence analysis can fully utilize over all information of DGA and give full play to the superiority of grey slope incidence, which overcomes shortcomings of original grey slope incidence analysis. The experimental results also demonstrate that the improved method has higher accuracy compared with three-ratio method and general grey slope incidence analysis method. The diagnosis accuracy is 92.8%.
Dong, Lieqian; Wang, Deying; Zhang, Yimeng; Zhou, Datong
2017-09-01
Signal enhancement is a necessary step in seismic data processing. In this paper we utilize the complementary ensemble empirical mode decomposition (CEEMD) and complex curvelet transform (CCT) methods to separate signal from random noise further to improve the signal to noise (S/N) ratio. Firstly, the original data with noise is decomposed into a series of intrinsic mode function (IMF) profiles with the aid of CEEMD. Then the IMFs with noise are transformed into CCT domain. By choosing different thresholds which are based on the noise level difference of each IMF profile, the noise in original data can be suppressed. Finally, we illustrate the effectiveness of the approach by simulated and field datasets.
INVARIAN AUTOMATIC CONTROL SYSTEM, USING THE INTERMEDIATE-FREQUENCY SIGNALS OF HEAT POWER PARAMETERS
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G. T. Kulakov
2015-01-01
Full Text Available The usage of digital micro-processing automatic means allow to use design methods (technique of automatic control systems more wider, and also to apply optimal ways of control, for example, it is possible to combine the Method of structural-parameter optimization and invariance theory. This method allow to increase essential system speed in processing of task jump and to reduce operation time of outside external disturbance up to two values of regulated influence, and the usage of invariance principle is based on an additional measuring of the most dangerous perturbation influence and in connection with it the improvement of regulation quality is achieved.In this article the principle of invariance is applied in order to improve greatly external disturbance attack by consumption of over-heated steam. Compensation of disturbance influence on regulated value is achieving by introduction of additional signal on input of correction regulator from output of compensation device, measuring the external disturbance by consumption of over-heated steam.Modeling results of transient processes of cascade system of automatic control (CSAC, on the base of which were realized the unity of these methods, demonstrated the fact that, in processing of external disturbance by consumption of steam, the reduction of maximal dynamic regulation error is six times and cutting of regulation time by 30 % in comparison with CSAC without compensation device of external disturbance. And that is why it leads to the further reduction of maximal dynamic regulation error in processing of external disturbance by consumption of steam, and this allows to improve the quality of control.
Complex use of waste in wastewater and circulating water treatment from oil in heat power stations
Nikolaeva, L. A.; Iskhakova, R. Ya.
2017-06-01
Sewage and circulating water from oil of thermal power plants (TPP) generated in fuel-oil shops during washing of electrical equipment and its running into the storm drainage system from the industrial site has been considered in the paper. It has been suggested to use the carbonate sludge of water treatment modified with hydrophobing emulsion as a sorption material for waste and circulating water treatment in thermal power plants. The carbonate sludge is waste accumulated in clarifiers at the stage of natural water pretreatment. General technical characteristics of the sludge, such as moisture, bulk density, total pore volume, ash, etc., have been determined. It has been found that the sludge without additional treatment is a hydrophilic material that has low adsorption capacity and wettability with nonpolar compounds. Therefore, the sludge is treated with organosilicon compounds to reduce the moisture capacity and increase its floatation. Several types of sorption materials based on the carbonate sludge subjected to surface and volume hydrophobization have been developed. During the volume treatment, the hydrophobing compound has been introduced into the material along with the plastifier. In case of the surface treatment, heat-treated granules have been soaked into hydrophobing emulsion. It has been shown that surface hydrophobization is most economically advantageous, because it reduces the consumption of water-repelling agent, wherein the total pore volume and sorption capacity during surface hydrophobization increase by 45 and 25% compared to that during volume hydrophobization. Based on the obtained results, the most effective sorption material has been chosen. To produce this material, it is necessary to sequentially carry out mixing of carbonate sludge with the binder, granulation, calcination, impregnation with a waterrepellent emulsion, and drying of the finished material. The suggested technology to produce the material and use it as a sorbent allows
Swept source optical coherence tomography based on non-uniform discrete fourier transform
Institute of Scientific and Technical Information of China (English)
Tong Wu; Zhihua Ding; Kai Wang; Chuan Wang
2009-01-01
A high-speed high-sensitivity swept source optical coherence tomography (SSOCT) system using a high speed swept laser source is developed.Non-uniform discrete fourier transform (NDFT) method is introduced in the SSOCT system for data processing.Frequency calibration method based on a Mach-Zender interferometer (MZI) and conventional data interpolation method is also adopted in the system for comparison.Optical coherence tomography (OCT) images from SSOCT based on the NDFT method,the MZI method,and the interpolation method are illustrated.The axial resolution of the SSOCT based on the NDFT method is comparable to that of the SSOCT system using MZI calibration method and conventional data interpolation method.The SSOCT system based on the NDFT method can achieve higher signal intensity than that of the system based on the MZI calibration method and conventional data interpolation method because of the better utilization of the power of source.
Lost in transformation? -Reviving ethics of care in hospital cultures of evidence-based healthcare
DEFF Research Database (Denmark)
Norlyk, Annelise; Haahr, Anita; Dreyer, Pia
2017-01-01
and values from evidence-based medicine are being lost in the transformation into the current evidence-based hospital culture which potentially leads to a McDonaldization of nursing practice reflected as ‘one best way’. We argue for reviving ethics of care perspectives in today’s evidence practice...... as the fundamental values of nursing may potentially bridge conflicts between evidence-based practice and the ideals of patient participation thus preventing a practice of ‘McNursing’. Key words: nursing practice, evidence-based practice, nursing theory, nursing theorists, ethics of care, hospital culture, patient......Drawing on our previous empirical research, we provide an exemplary narrative to illustrate how patients have experienced hospital care organized according to evidence-based fast-track programmes. The aim of this paper is to analyse and discuss if and how it is possible to include patients...
Zhang, Yu-xin; Cheng, Zhi-feng; Xu, Zheng-ping; Bai, Jing
2015-01-01
In order to solve the problems such as complex operation, consumption for the carrier gas and long test period in traditional power transformer fault diagnosis approach based on dissolved gas analysis (DGA), this paper proposes a new method which is detecting 5 types of characteristic gas content in transformer oil such as CH4, C2H2, C2H4, C2H6 and H2 based on photoacoustic Spectroscopy and C2H2/C2H4, CH4/H2, C2H4/C2H6 three-ratios data are calculated. The support vector machine model was constructed using cross validation method under five support vector machine functions and four kernel functions, heuristic algorithms were used in parameter optimization for penalty factor c and g, which to establish the best SVM model for the highest fault diagnosis accuracy and the fast computing speed. Particles swarm optimization and genetic algorithm two types of heuristic algorithms were comparative studied in this paper for accuracy and speed in optimization. The simulation result shows that SVM model composed of C-SVC, RBF kernel functions and genetic algorithm obtain 97. 5% accuracy in test sample set and 98. 333 3% accuracy in train sample set, and genetic algorithm was about two times faster than particles swarm optimization in computing speed. The methods described in this paper has many advantages such as simple operation, non-contact measurement, no consumption for the carrier gas, long test period, high stability and sensitivity, the result shows that the methods described in this paper can instead of the traditional transformer fault diagnosis by gas chromatography and meets the actual project needs in transformer fault diagnosis.
Zhang, Leihong; Liang, Dong; Li, Bei; Kang, Yi; Pan, Zilan; Zhang, Dawei; Gao, Xiumin; Ma, Xiuhua
2016-07-01
On the basis of analyzing the cosine light field with determined analytic expression and the pseudo-inverse method, the object is illuminated by a presetting light field with a determined discrete Fourier transform measurement matrix, and the object image is reconstructed by the pseudo-inverse method. The analytic expression of the algorithm of computational ghost imaging based on discrete Fourier transform measurement matrix is deduced theoretically, and compared with the algorithm of compressive computational ghost imaging based on random measurement matrix. The reconstruction process and the reconstruction error are analyzed. On this basis, the simulation is done to verify the theoretical analysis. When the sampling measurement number is similar to the number of object pixel, the rank of discrete Fourier transform matrix is the same as the one of the random measurement matrix, the PSNR of the reconstruction image of FGI algorithm and PGI algorithm are similar, the reconstruction error of the traditional CGI algorithm is lower than that of reconstruction image based on FGI algorithm and PGI algorithm. As the decreasing of the number of sampling measurement, the PSNR of reconstruction image based on FGI algorithm decreases slowly, and the PSNR of reconstruction image based on PGI algorithm and CGI algorithm decreases sharply. The reconstruction time of FGI algorithm is lower than that of other algorithms and is not affected by the number of sampling measurement. The FGI algorithm can effectively filter out the random white noise through a low-pass filter and realize the reconstruction denoising which has a higher denoising capability than that of the CGI algorithm. The FGI algorithm can improve the reconstruction accuracy and the reconstruction speed of computational ghost imaging.
Energy Technology Data Exchange (ETDEWEB)
Manini, A
2002-07-01
development of this work, the Electron Cyclotron Emission system (ECE) of ASDEX Upgrade is crucial since it allows local measurements of the electron temperature with high temporal and spatial resolutions. The analysis and interpretation of perturbative MECH discharges for power deposition localisation using different diagnostics, such as ECE and SXR measurements, are presented. The most important problem is related to the phase locking between the MECH and the sawtooth activity of the plasma, which disturbs both ECE and SXR measurements. Several techniques have been adopted to circumvent this difficulty. In particular, the Singular Value Decomposition (SVD) and the Generalised Singular Value Decomposition (GSVD) have been tested in both TCV and ASDEX Upgrade discharges. However, both methods are incapable of treating the problem correctly, which leads to potential misinterpretation of the results. A new method based on system identification using the SVD (SI-SVD) is developed and applied. This method, within reasonable limits induced by the assumption of linearity, is capable of simultaneously separating the MECH from the sawtooth contributions to both ECE electron temperature measurements and SXR emission measurements. Such a method is in particular applied to a NBI heated ASDEX Upgrade discharge in which MECH is added in order to analyse electron heat transport in a mostly ion-heated plasma. Since the NBI heating is also partly modulated with short pulses, which coincide with the sawtooth crashes to improve their stability, both the MECH and the NBI deposition profiles are determined. Moreover, treating the signals with the SI-SVD procedure enables a study of the plasma dynamic response also at higher MECH harmonic numbers. The procedure is then used to analyse MECH discharges in TCV using different diagnostics. The profiles determined using the ECE and soft X-ray measurements are compared and interpreted, demonstrating in particular that line integrated soft X
Energy Technology Data Exchange (ETDEWEB)
Manini, A
2002-07-01
development of this work, the Electron Cyclotron Emission system (ECE) of ASDEX Upgrade is crucial since it allows local measurements of the electron temperature with high temporal and spatial resolutions. The analysis and interpretation of perturbative MECH discharges for power deposition localisation using different diagnostics, such as ECE and SXR measurements, are presented. The most important problem is related to the phase locking between the MECH and the sawtooth activity of the plasma, which disturbs both ECE and SXR measurements. Several techniques have been adopted to circumvent this difficulty. In particular, the Singular Value Decomposition (SVD) and the Generalised Singular Value Decomposition (GSVD) have been tested in both TCV and ASDEX Upgrade discharges. However, both methods are incapable of treating the problem correctly, which leads to potential misinterpretation of the results. A new method based on system identification using the SVD (SI-SVD) is developed and applied. This method, within reasonable limits induced by the assumption of linearity, is capable of simultaneously separating the MECH from the sawtooth contributions to both ECE electron temperature measurements and SXR emission measurements. Such a method is in particular applied to a NBI heated ASDEX Upgrade discharge in which MECH is added in order to analyse electron heat transport in a mostly ion-heated plasma. Since the NBI heating is also partly modulated with short pulses, which coincide with the sawtooth crashes to improve their stability, both the MECH and the NBI deposition profiles are determined. Moreover, treating the signals with the SI-SVD procedure enables a study of the plasma dynamic response also at higher MECH harmonic numbers. The procedure is then used to analyse MECH discharges in TCV using different diagnostics. The profiles determined using the ECE and soft X-ray measurements are compared and interpreted, demonstrating in particular that line integrated soft X
Two-Stream Transformer Networks for Video-based Face Alignment.
Liu, Hao; Lu, Jiwen; Feng, Jianjiang; Zhou, Jie
2017-08-01
In this paper, we propose a two-stream transformer networks (TSTN) approach for video-based face alignment. Unlike conventional image-based face alignment approaches which cannot explicitly model the temporal dependency in videos and motivated by the fact that consistent movements of facial landmarks usually occur across consecutive frames, our TSTN aims to capture the complementary information of both the spatial appearance on still frames and the temporal consistency information across frames. To achieve this, we develop a two-stream architecture, which decomposes the video-based face alignment into spatial and temporal streams accordingly. Specifically, the spatial stream aims to transform the facial image to the landmark positions by preserving the holistic facial shape structure. Accordingly, the temporal stream encodes the video input as active appearance codes, where the temporal consistency information across frames is captured to help shape refinements. Experimental results on the benchmarking video-based face alignment datasets show very competitive performance of our method in comparisons to the state-of-the-arts.
Institute of Scientific and Technical Information of China (English)
HU; Xingtang; ZHANG; Bing; ZHANG; Xia; ZHENG; Lanfen; TONG; Qingxi
2006-01-01
Starting with a fractal-based image-compression algorithm based on wavelet transformation for hyperspectral images, the authors were able to obtain more spectral bands with the help of of hyperspectral remote sensing. Because large amounts of data and limited bandwidth complicate the storage and transmission of data measured by TB-level bits, it is important to compress image data acquired by hyperspectral sensors such as MODIS, PHI, and OMIS; otherwise, conventional lossless compression algorithms cannot reach adequate compression ratios. Other loss-compression methods can reach high compression ratios but lack good image fidelity, especially for hyperspectral image data. Among the third generation of image compression algorithms, fractal image compression based on wavelet transformation is superior to traditional compression methods,because it has high compression ratios and good image fidelity, and requires less computing time. To keep the spectral dimension invariable, the authors compared the results of two compression algorithms based on the storage-file structures of BSQ and of BIP, and improved the HV and Quadtree partitioning and domain-range matching algorithms in order to accelerate their encode/decode efficiency. The authors' Hyperspectral Image Process and Analysis System (HIPAS) software used a VC++6.0 integrated development environment (IDE), with which good experimental results were obtained. Possible modifications of the algorithm and limitations of the method are also discussed.
Optical image encryption based on a joint Fresnel transform correlator with double optical wedges.
Shen, Xueju; Dou, Shuaifeng; Lei, Ming; Chen, Yudan
2016-10-20
An optical cryptosystem based on the joint Fresnel transform correlator (JFTC) with double optical wedges is designed. The designed cryptosystem retains the two major advantages of JTC-based optical cryptosystems. First, the encrypted image is real-valued and therefore is easier to record and transmit. Second, the encryption process is simplified, since it doesn't require accurate alignment of optical elements or the generation of the complex conjugate of the key. Also, the designed optical cryptosystem can produce a decrypted image with higher quality than a JTC-based optical cryptosystem, because the original encrypted image is divided by the Fresnel transform power distribution of the key mask to generate the new encrypted image, which significantly reduces the noise during the decryption process. Simulation results showed that the correlation coefficient of the decrypted image and the original image can reach as large as 0.9819 after denoising and adequately selecting half-central interval a and encrypted image width w. Another improvement relative to JTC-based optical cryptosystems is that the attack resistibility gets enhanced due to the nonlinearity of the encryption process as well as the additional key parameter a, which enlarges the key space.
Directory of Open Access Journals (Sweden)
A. Al-Haj
2008-01-01
Full Text Available The excellent spatial localization, frequency spread and multi-resolution characteristics of the Discrete Wavelets Transform (DWT, which were similar to the theoretical models of the human visual system, facilitated the development of many imperceptible and robust DWT-based watermarking algorithms. There had been extremely few proposed algorithms on optimized DWT-based image watermarking that can simultaneously provide perceptual transparency and robustness since these two watermarking requirements are conflicting, in this study we treat the DWT-based image watermarking problem as an optimization problem and solve it using genetic algorithms. We demonstrate through the experimental results we obtained that optimal DWT-based image watermarking can be achieved only if watermarking has been applied at specific wavelet sub-bands and by using specific watermark-amplification values.
Gu, Junhua; Wang, Jingying; An, Tao; Chen, Wen
2013-01-01
We propose a continuous wavelet transform based non-parametric foreground subtraction method for the detection of redshifted 21 cm signal from the epoch of reionization. This method works based on the assumption that the foreground spectra are smooth in frequency domain, while the 21 cm signal spectrum is full of saw-tooth-like structures, thus their characteristic scales are significantly different. We can distinguish them in the wavelet coefficient space easily and perform the foreground subtraction. Compared with the traditional spectral fitting based method, our method is more tolerant to complex foregrounds. Furthermore, we also find that when the instrument has uncorrected response error, our method can also work significantly better than the spectral fitting based method. Our method can obtain similar results with the Wp smoothing method, which is also a non-parametric method, but our method consumes much less computing time.
Investigation of PAPR in Discrete Wavelet Transform based Multi-carrier Systems
Directory of Open Access Journals (Sweden)
Neha S
2015-10-01
Full Text Available The objective of the paper is to formulate a measure to reduce PAPR problem in Orthogonal Frequency Division Multiplexing. To mitigate the problem of PAPR, a Discrete Wavelet Transform based system is employed instead of conventional OFDM. For the comparative study, the PAPR in conventional OFDM is analyzed for varying number of subcarriers and for different channel taps. The result of conventional OFDM is compared with wavelet based OFDM, employing wavelets namely - ‘Haar’, ‘Daubechies’, ‘Symlets’ and ‘Biorthogonal’ wavelets. Further the PAPR is analyzed for varying levels and different length of channel impulse response. The simulation results show that wavelet based OFDM has less PAPR than conventional OFDM. With the increase in the number level, the PAPR at the demodulator side decreases in the wavelet based OFDM.
New approach to ECE measurements based on Hilbert-transform spectral analysis
Directory of Open Access Journals (Sweden)
Pandya Hitesh Kumar B.
2015-01-01
Full Text Available Spectroscopy of Electron Cyclotron Emission (ECE has been established as adequate diagnostic technique for fusion research machines. Among various instruments for ECE diagnostics, only Fourier-transform spectrometers with Martin-Puplett interferometers can measure electron cyclotron radiation in a broadband frequency range from 70 to 1000 GHz. Before these measurements, a complete system including a frontend radiation collector, a transmission line, an interferometer and a radiation detector should be absolutely calibrated. A hot/cold calibration source and data-averaging technique are used to calibrate the total ECE diagnostic system. It takes long time to calibrate the ECE system because of the low power level of the calibration source and high values of the noise equivalent power (NEP of the detection system. A new technique, Hilbert-transform spectral analysis, is proposed for the ITER plasma ECE spectral measurements. An operation principle, characteristics and advantages of the corresponding Hilbert-transform spectrum analyser (HTSA based on a high-Tc Josephson detector are discussed. Due to lower NEP-values of the Josephson detector, this spectrum analyser might demonstrate shorter calibration times than that for the Martin-Puplett interferometer.
Hamilton, D Kirk; Orr, Robin Diane; Raboin, W Ellen
2008-01-01
Healthcare organizations face continuous and accelerating external change and thus must be prepared to manage their own change initiatives proactively. Given that many believe that the U.S. healthcare system is broken and most healthcare organizations are dealing with pervasive problems, some organizations may choose to seek transformational change to achieve the six aims identified by the Institute of Medicine: healthcare that is safe, effective, patient-centered, timely, efficient, and equitable. Transformational change will almost certainly involve organizational culture. Culture change may be most effective when linked to other organizational change initiatives such as organizational strategy, structure, policies, procedures, and recruiting. Significant organizational change often requires accompanying facility change. There is an interdependent relationship between facility design and organizational culture. They affect each other and both impact organizational performance. Sociotechnical theory promotes joint optimization of the social (culture) and technical (facilities) aspects of an organization to achieve sustained positive change. To achieve organizational transformation and to sustain positive change, organizations must be prepared to adopt collaborative efforts in culture change and facility design. The authors propose a model for accomplishing joint optimization of culture change and evidence-based facility design.
Evaluation of Harmonic Content from a Tap Transformer Based Grid Connection System for Wind Power
Directory of Open Access Journals (Sweden)
S. Apelfröjd
2013-01-01
Full Text Available Simulations done in MATLAB/Simulink together with experiments conducted at the Ångströms laboratory are used to evaluate and discuss the total harmonic distortion (THD and total demand distortion (TDD of a tap transformer based grid connection system. The grid connection topology can be used with different turbine and generator topologies and is here applied on a vertical axis wind turbine (VAWT with a permanent magnet synchronous generator (PMSG and its operational scheme. The full variable-speed wind conversion system consists of a diode rectifier, DC link, IGBT inverter, LCL-filter, and tap transformer. The full variable-speed operation is enabled by the use of the different step-up ratios of the tap transformer. In the laboratory study, a full experimental setup of the system was used, a clone of the on-site PMSG driven by a motor was used, and the grid was replaced with a resistive load. With a resistive load, grid harmonics and possible unbalances are removed. The results show a TDD and THD below 5% for the full operating range and harmonic values within the limits set up by IEEE-519. Furthermore, a change in tap, going to a lower step-up ratio, results in a reduction in both THD and TDD for the same output power.
Wu, H W; Wang, F; Dong, Y Q; Shu, F Z; Zhang, K; Peng, R W; Xiong, X; Wang, Mu
2015-12-14
In this work, we theoretically study the cavity modes with transverse orbital angular momentum in metamaterial ring based on transformation optics. The metamaterial ring is designed to transform the straight trajectory of light into the circulating one by enlarging the azimuthal angle, effectively presenting the modes with transverse orbital angular momentum. The simulation results confirm the theoretical predictions, which state that the transverse orbital angular momentum of the mode not only depends on the frequency of the incident light, but also depends on the transformation scale of the azimuthal angle. Because energy dissipation inevitably reduces the field amplitude of the modes, the confined electromagnetic energy and the quality factor of the modes inside the ring are also studied in order to evaluate the stability of those cavity modes. The results show that the metamaterial ring can effectively confine light with a high quality factor and maintain steady modes with the orbital angular momentum, even if the dimension of the ring is much smaller than the wavelength of the incident light. This technique for exploiting the modes with optical transverse orbital angular momentum may provides a unique platform for applications related to micromanipulation.
Double-image encryption based on discrete fractional random transform and chaotic maps
Li, Huijuan; Wang, Yurong
2011-07-01
A novel double-image encryption algorithm is proposed, based on discrete fractional random transform and chaotic maps. The random matrices used in the discrete fractional random transform are generated by using a chaotic map. One of the two original images is scrambled by using another chaotic map, and then encoded into the phase of a complex matrix with the other original image as its amplitude. Then this complex matrix is encrypted by the discrete fractional random transform. By applying the correct keys which consist of initial values, control parameters, and truncated positions of the chaotic maps, and fractional orders, the two original images can be recovered without cross-talk. Numerical simulation has been performed to test the validity and the security of the proposed encryption algorithm. Encrypting two images together by this algorithm creates only one encrypted image, whereas other single-image encryption methods create two encrypted images. Furthermore, this algorithm requires neither the use of phase keys nor the use of matrix keys. In this sense, this algorithm can raise the efficiency when encrypting, storing or transmitting.
An 8-GW long-pulse generator based on Tesla transformer and pulse forming network.
Su, Jiancang; Zhang, Xibo; Li, Rui; Zhao, Liang; Sun, Xu; Wang, Limin; Zeng, Bo; Cheng, Jie; Wang, Ying; Peng, Jianchang; Song, Xiaoxin
2014-06-01
A long-pulse generator TPG700L based on a Tesla transformer and a series pulse forming network (PFN) is constructed to generate intense electron beams for the purpose of high power microwave (HPM) generation. The TPG700L mainly consists of a 12-stage PFN, a built-in Tesla transformer in a pulse forming line, a three-electrode gas switch, a transmission line with a trigger, and a load. The Tesla transformer and the compact PFN are the key technologies for the development of the TPG700L. This generator can output electrical pulses with a width as long as 200 ns at a level of 8 GW and a repetition rate of 50 Hz. When used to drive a relative backward wave oscillator for HPM generation, the electrical pulse width is about 100 ns on a voltage level of 520 kV. Factors affecting the pulse waveform of the TPG700L are also discussed. At present, the TPG700L performs well for long-pulse HPM generation in our laboratory.
A method based on IHS cylindrical transform model for quality assessment of image fusion
Zhu, Xiaokun; Jia, Yonghong
2005-10-01
Image fusion technique has been widely applied to remote sensing image analysis and processing, and methods for quality assessment of image fusion in remote sensing have also become the research issues at home and abroad. Traditional assessment methods combine calculation of quantitative indexes and visual interpretation to compare fused images quantificationally and qualitatively. However, in the existing assessment methods, there are two defects: on one hand, most imdexes lack the theoretic support to compare different fusion methods. On the hand, there is not a uniform preference for most of the quantitative assessment indexes when they are applied to estimate the fusion effects. That is, the spatial resolution and spectral feature could not be analyzed synchronously by these indexes and there is not a general method to unify the spatial and spectral feature assessment. So in this paper, on the basis of the approximate general model of four traditional fusion methods, including Intensity Hue Saturation(IHS) triangle transform fusion, High Pass Filter(HPF) fusion, Principal Component Analysis(PCA) fusion, Wavelet Transform(WT) fusion, a correlation coefficient assessment method based on IHS cylindrical transform is proposed. By experiments, this method can not only get the evaluation results of spatial and spectral features on the basis of uniform preference, but also can acquire the comparison between fusion image sources and fused images, and acquire differences among fusion methods. Compared with the traditional assessment methods, the new methods is more intuitionistic, and in accord with subjective estimation.
Recognition Method of Aircraft Axis Direction Based on Morphological Skeleton and Hough Transform
Institute of Scientific and Technical Information of China (English)
WANG Hong-bo; ZHUANG Zhi-hong; ZHENG Hua-li; ZHANG Qing-tai; HE Hong-jun
2008-01-01
Because of the limit of angle of view(AOV) of IR imaging seeker during the approach of missile and target, the detector can only get the partial image sequence of aircraft nose after "lose point". Recognizing the axis direction on the basis of partial IR image sequence is a key issue of the advanced IR imaging guide air-to-air missile faced. In this paper, a recognition method was proposed based on the morphological skeleton and modified Hough transform, and this method can recognize correctly the axis direction of aircraft nose in different poses during missile-target encounter. Firstly, the morphological skeleton transform was used for the extraction of skeleton features. Secondly, the modified Hough transform was used for the straight-lines detection. Finally, According to the relations between aircraft nose and axis and invariant of nose features in high-speed IR image sequence, the axis direction can be detected and calculated. Experimental results indicate that the method is feasible and effective, and the precision of axis direction recognized can meet the requirement of accurate burst control of GIF fuze.
Directory of Open Access Journals (Sweden)
Bai-ling Zhang
2006-07-01
Full Text Available Face recognition can be studied as an associative memory (AM problem and kernel-based AM models have been proven efficient. In this paper, a hierarchical Kernel Associative Memory (KAM face recognition scheme with a multiscale Gabor transform, is proposed. The pyramidal multiscale Gabor decomposition proposed by Nestares, Navarro, Portilla and Tabernero not only provides a very efficient implementation of the Gabor transform in the spatial domain, but also permits a fast reconstruction of images. In our method, face images of each person are first decomposed into their multiscale representations by a quasicomplete Gabor transform, which are then modelled by Kernel Associative Memories. In the recognition stage, a query face image is also represented by a Gabor multiresolution pyramid and the reconstructions from different KAM models corresponding to even Gabor channels are then simply summed to give the recall. The recognition scheme was thoroughly tested using several benchmarking face datasets, including the AR faces, UMIST faces, JAFFE faces and Yale A faces, which include different kind of face variations from occlusions, pose, expression and illumination. The experiment results show that the proposed method demonstrated strong robustness in recognizing faces under different conditions, particularly under occlusions, pose alterations and expression changes.
Power Transformer Partial Discharge Fault Diagnosis Based on Multidimensional Feature Region
Directory of Open Access Journals (Sweden)
Rong Jia
2016-01-01
Full Text Available Effectively extracting power transformer partial discharge (PD signals feature is of great significance for monitoring power transformer insulation condition. However, there has been lack of practical and effective extraction methods. For this reason, this paper suggests a novel method for the PD signal feature extraction based on multidimensional feature region. Firstly, in order to better describe differences in each frequency band of fault signals, empirical mode decomposition (EMD and Hilbert-Huang transform (HHT band-pass filter wave for raw signal is carried out. And the component of raw signals on each frequency band can be obtained. Secondly, the sample entropy value and the energy value of each frequency band component are calculated. Using the difference of each frequency band energy and complexity, signals feature region is established by the multidimensional energy parameters and the multidimensional sample entropy parameters to describe PD signals multidimensional feature information. Finally, partial discharge faults are classified by sphere-structured support vector machines algorithm. The result indicates that this method is able to identify and classify different partial discharge faults.
Analysis of the Chirplet Transform-Based Algorithm for Radar Detection of Accelerated Targets
Galushko, V. G.; Vavriv, D. M.
2017-06-01
Purpose: Efficiency analysis of an optimal algorithm of chirp signal processing based on the chirplet transform as applied to detection of radar targets in uniformly accelerated motion. Design/methodology/approach: Standard methods of the optimal filtration theory are used to investigate the ambiguity function of chirp signals. Findings: An analytical expression has been derived for the ambiguity function of chirp signals that is analyzed with respect to detection of radar targets moving at a constant acceleration. Sidelobe level and characteristic width of the ambiguity function with respect to the coordinates frequency and rate of its change have been estimated. The gain in the signal-to-noise ratio has been assessed that is provided by the algorithm under consideration as compared with application of the standard Fourier transform to detection of chirp signals against a “white” noise background. It is shown that already with a comparatively small (block diagram of implementation of the algorithm under consideration is suggested on the basis of a multichannel weighted Fourier transform. Recommendations as for selection of the detection algorithm parameters have been developed. Conclusions: The obtained results testify to efficiency of application of the algorithm under consideration to detection of radar targets moving at a constant acceleration. Nevertheless, it seems expedient to perform computer simulations of its operability with account for the noise impact along with trial measurements in real conditions.
A compact bipolar pulse-forming network-Marx generator based on pulse transformers
Zhang, Huibo; Yang, Jianhua; Lin, Jiajin; Yang, Xiao
2013-11-01
A compact bipolar pulse-forming network (PFN)-Marx generator based on pulse transformers is presented in this paper. The high-voltage generator consisted of two sets of pulse transformers, 6 stages of PFNs with ceramic capacitors, a switch unit, and a matched load. The design is characterized by the bipolar pulse charging scheme and the compact structure of the PFN-Marx. The scheme of bipolar charging by pulse transformers increased the withstand voltage of the ceramic capacitors in the PFNs and decreased the number of the gas gap switches. The compact structure of the PFN-Marx was aimed at reducing the parasitic inductance in the generator. When the charging voltage on the PFNs was 35 kV, the matched resistive load of 48 Ω could deliver a high-voltage pulse with an amplitude of 100 kV. The full width at half maximum of the load pulse was 173 ns, and its rise time was less than 15 ns.
A New OFDM System Based on Lifting Wavelet Transform for Wireless Channel
Institute of Scientific and Technical Information of China (English)
GAO Jian-bo; ZHAO Er-yuan
2005-01-01
It is well known that the Orthogonal Frequency Division Multiplexing(OFDM) system has a high ability to overcome the effect of multipath and can obtain high spectral efficiency in the wireless communication channel. However, avoid Interchannel Interference (ICI) and Intersymbol Interference (ISI) in wireless channel, a guard interval longer than channel delay is used in conventional OFDM system, which cause the efficiency of bandwidth usage reduced. Due to the superior spectral containment of wavelets, this paper proposed a new OFDM system based on Lifting Wavelet Transform (LWT-OFDM), which adopts lifting wavelet transform to replace the conventional Fourier transform. This new OFDM system doesn't need the Cyclic Prefix (CP) so its structure is more simply than FFT-OFDM and its algorithm is as simply as FFT-OFDM. The new LWT-OFDM system can mitigates some disadvantages of FFT-OFDM system, such as a relatively large peak-to-average power ratio, more sensitive to carrier frequency offset and phase noise. Simulations show that the LWT-OFDM system is more effective and attractive than conversional FFT-OFDM in wireless channel.
Wu, Changdong; Liu, Zhigang; Jiang, Hua
2017-05-01
The quality of image enhancement plays an important role in the catenary fault diagnosis system based on the image processing technique. It is necessary to enhance the low contrast image of catenary for better detecting the state of catenary part. The Non-subsampled Contourlet transform (NSCT) is the improved Contourlet transform (CT), which can effectively solve the problem of artifact phenomenon in the enhanced catenary image. Besides, choosing the enhancement function and the filter of the NSCT will directly influence the image enhancement effect. In this paper, the proposed method is implemented by combining the NSCT with the nonlinear enhancement function to enhance the catenary image. First, how to choose the filter of the NSCT is discussed. Second, the NSCT is used to decompose the image. Then, the chosen nonlinear enhancement function is used to process the decomposed coefficient of the NSCT. Finally, the NSCT is inversed to obtain the enhanced image. In this paper, we evaluate our algorithm using the lifting wavelet transform, retinex enhancement method, dark channel enhancement method, curvelet transform, and CT method as a comparison to enhance a group of randomly selected low contrast catenary images, respectively. The results of comparative experiments conducted show that the proposed method can effectively enhance the catenary image, the contrast of image is improved, the catenary parts are obvious, and the artifact phenomenon is effectively eliminated, where image details (edges, textures, or smooth areas) are also well preserved. Besides, the values (detail variance-background variance, signal-to-noise ratio, and edge preservation index) of measuring the image enhancement capacity are improved, while the mean squared error value is decreased when compared to the CT method. These indicate that the proposed method is an excellent catenary image enhancement approach.
Institute of Scientific and Technical Information of China (English)
马文君; 牟龙华
2011-01-01
变电站数字化改造中需对传统的微机保护装置进行IEC 61850升级改造.以变压器微机保护为例,在硬件上增加了通信模块,使其具有网络化的功能；在软件上对变压器保护进行功能分解和逻辑节点确定,新建了IEC 61850中没有定义的瓦斯保护逻辑节点类PGAS,分析了差动保护的具体实现流程.构建了IEC61850服务器模型,完成了变压器微机保护装置的IEC61850数据建模,使其符合IEC 61850通信标准.改造方法简单,成本低廉,适应现阶段的数字化变电站,具有较好的参考意义和应用价值.%It is necessary to update the traditional microprocessor-based protection device to meet IEC 61850 in the transformation of digital substation. Taking the transformer protection as an example, this paper adds communication module to original hardware to realize network function. In the software, transformer functions are decomposed and identified by corresponding logic nodes; gas protection logic node class PGAS. Which is not defined in IEC 61850. Is newly developed; implementation process of differential protection is concretely analyzed; finally IEC 61850 server model is constructed, thus completing IEC 61850 data modeling of microcomputer-based transformer protection, which meets IEC 61850 standard. The transformation is simple,cheap and adaptable to current digital substation, with good reference significance and application value.
Energy Technology Data Exchange (ETDEWEB)
Ohtsuka, H.; Wada, H. [Tsukuba Labs., Ibaraki (Japan). Nat. Res. Inst. for Metals; Ghosh, G. [Northwestern Univ., Evanston, IL (United States). Dept. of Materials Science and Engineering
2000-07-01
Effects of magnetic field on lath-type martensitic transformation behavior and the reverse transformation behavior from lath math martensite to austenite have been investigated in 18Ni maraging steel. It was found that the reverse transformation temperature during heating is increased by magnetic field. Reverse transformation behavior during isothermal holding was also found to be retarded by magnetic field. (orig.)
WSCDL to WSBPEL: A Case Study of ATL-based Transformation
Khadka, Ravi; Sapkota, Brahmananda; Ferreira Pires, Luis; Sinderen, van Marten; Jansen, Slinger; Kurtev, Ivan; Tisi, Massimo; Wagelaar, Dennis
2011-01-01
The ATLAS Transformation Language (ATL) is a hybrid transformation language that combines declarative and imperative programming elements and provides means to define model transformations. Most transformations using ATL reported in the literature show a simplified use of ATL, and often involve a si
De-noising of digital image correlation based on stationary wavelet transform
Guo, Xiang; Li, Yulong; Suo, Tao; Liang, Jin
2017-03-01
In this paper, a stationary wavelet transform (SWT) based method is proposed to de-noise the digital image with the light noise, and the SWT de-noise algorithm is presented after the analyzing of the light noise. By using the de-noise algorithm, the method was demonstrated to be capable of providing accurate DIC measurements in the light noise environment. The verification, comparative and realistic experiments were conducted using this method. The result indicate that the de-noise method can be applied to the full-field strain measurement under the light interference with a high accuracy and stability.
Directory of Open Access Journals (Sweden)
Guoliang Zhao
2013-01-01
Full Text Available This paper proposes new methodologies for the design of adaptive integral-sliding mode control. A tensor product model transformation based adaptive integral-sliding mode control law with respect to uncertainties and perturbations is studied, while upper bounds on the perturbations and uncertainties are assumed to be unknown. The advantage of proposed controllers consists in having a dynamical adaptive control gain to establish a sliding mode right at the beginning of the process. Gain dynamics ensure a reasonable adaptive gain with respect to the uncertainties. Finally, efficacy of the proposed controller is verified by simulations on an uncertain nonlinear system model.
Zhao, Guoliang; Sun, Kaibiao; Li, Hongxing
2013-01-01
This paper proposes new methodologies for the design of adaptive integral-sliding mode control. A tensor product model transformation based adaptive integral-sliding mode control law with respect to uncertainties and perturbations is studied, while upper bounds on the perturbations and uncertainties are assumed to be unknown. The advantage of proposed controllers consists in having a dynamical adaptive control gain to establish a sliding mode right at the beginning of the process. Gain dynamics ensure a reasonable adaptive gain with respect to the uncertainties. Finally, efficacy of the proposed controller is verified by simulations on an uncertain nonlinear system model.