Improving extraction of watermarks in color attacked watermarked images

A new approach for modeling color attacks of RGB-color watermarked images is presented in this paper. We have used a based interpolation watermarking algorithm and supposed that the attacks are simulated by a scaling of the colors followed by a translation. Then give bounds for the extracted watermark depending on the original image, the watermark and the attack. Different attacks like LSB, embedding another watermark, Stirmark have been simulated and the quality of the extracted watermark is discussed in each case.     

Audio recording of rock/metal music using personal computers

Personal computers and their relevant technologies have been widely used by artists and musicians to create and record their own music and electroacoustic compositions. ＂Laptoppers＂ are famous for using their laptops for their dance/electronic beats and music. A genre that has not relied on the use of PCs for the production of its music is rock/heavy metal, since bands of these genres usually book recording studio time where professionals take on the task of the production using expensive equipment. This study shows that in today＇s day and age, and with the software and hardware currently available, it is possible for rock/metal artists to use their PC to record and produce their own CD successfully and at an extremely competitive cost. The effort＇s of a rock band that does just this is followed from the beginning and the results of their CD production and song successes is presented. The article also serves as a ＂HowTo＂ guide that bands on a low budget can follow to make good quality demo CDs and enter the music business industry.     

Unsupervised image segmentation based on MRFs and graph cuts

Markov random fields （MRFs） can be used for a wide variety of vision problems. In this paper we will propose a Markov random field （MRF） image segmentation model. The theoretical framework is based on Bayesian estimation via the energy optimization. Graph cuts have emerged as a powerful optimization technique for minimizing energy functions that arise in low-level vision problem. The theorem of Ford and Fulkerson states that min-cut and max-flow problems are equivalent. So, the minimum s/t cut problem can be solved by finding a maximum flow from the source s to the sink t. we adopt a new min-cut/max-flow algorithm which belongs to the group of algorithms based on augmenting paths. We propose a parameter estimation method using expectation maximization （EM） algorithm. We also choose Gaussian mixture model as our image model and model the density associated with one of image segments （or classes） as a multivariate Gaussian distribution. Characteristic features related to the information in color, texture and position are extracted for each pixel. Experimental results will be provided to illustrate the performance of our method.     

Power efficient scheme for self localization in wireless sensor networks

With the tremendous applications of the wireless sensor network, self-localization has become one of the challenging subject matter that has gained attention of many researchers in the field of wireless sensor network. Localization is the process of assigning or computing the location of the sensor nodes in a sensor network. As the sensor nodes are deployed randomly, we do not have any knowledge about their location in advance. As a result, this becomes very important that they localize themselves as manual deployment of sensor node is not feasible. Also, in WSN the main problem is the power as the sensor nodes have very limited power source. This paper provides a novel solution for localizing the sensor nodes using controlled power of the beacon nodes such that we will have longer life of the beacon nodes which plays a vital role in the process of localization as it is the only special nodes that has the information about its location when they are deployed such that the remaining ordinary nodes can localize themselves in accordance with these beacon node. We develop a novel model that first finds the distance of the sensor nodes then it finds the location of the unknown sensor nodes in power efficient manner. Our simulation results show the effectiveness of the proposed methodology in terms of controlled and reduced power.     

Application of data warehouse in power transformer diagnosis system

Electric power companies have accumulated huge amounts of historical fault data of power transformer after many years operation, but the decision-makers have not been greatly supported because of the limitation of knowledge and can not make decision for transformer condition assessment. A real power corporation is selected as the research background. Based on analyzing and reorganizing the various existing data sources, the power transformer fault information data warehouse is constructed and snowflake mode cubes for multi-dimension data are established. By using Processing） and data mining analyzing and inquiring data OLAP（On-Line Analysis technology, forecasting load, warehouse are realized from different point view and multi-layers, including rolling up, drilling down, slicing, dicing and rotating etc.. Moreover, this paper proposes a novel transformer fault data mining system based on data warehouse. Finally, bayes network of fault patterns are obtained, which can greatly help the decision-making for the system operating and management. The results show that transformer fault diagnosing system based on data warehouse technology can provide efficient decision supporting.     

Rescheduling to minimize total completion time under a limit on the makespan of the original jobs

We consider the rescheduling problems arising when two agents, each with a set of nonpreemptive jobs, compete to perform their respective jobs on a common processing resource. Each agent wants to minimize a certain objective function, which depends on the completion time of its jobs only. In this paper, we consider the two agents rescheduling problems for jobs on a single machine to minimize total completion time under a limit on the makespan of the original jobs. We show that the considered problems can be solved in polynomial time or pseudopolynomial time.     

Analysis and design of light emitting diodes for optoelectronic applications

This paper presents detailed analysis and design of light-emitting diodes for optoelectronic applications. Both internal and external efficiencies are investigated taking into account the nonradiative recombination process and the total internal reflection. The dependency of the LED output power on the efficiency and double pass parasitic absorption is studied. Effect of the temperature variation on the LED performance is also studied. A complete design of an encapsulated LED operating at 1.55 m has been investigated. The design illustrates layer structures and thickness, material compositions, and index of refraction. The results show that decreasing the radiation recombination time increases the quantum efficiency, The quantum efficiency increases from 15% to 70% as the radiative recombination time reduced from 0.5 s to 0.05 s. It is also shown that increasing the width of the active region increases the output power.     

Service for consistency management of replicas in data grid

Today, grid technology has evolved to the point where it is no longer a theory but a proven practice. It represents a viable direction for corporations to explore grid computing as an answer to their business needs within tight financial constraints. In general, grids enable the efficient sharing and management of computing resources for the purpose of performing large complex tasks. Data grid provides the data management features to enable data access, synchronization, and distribution of a grid. The main aim here is to ensure a efficient access and quality data, to improve the availability, and be able to continue delivering acceptable services. In such systems, these advantages are not yielded by means others than replication mechanisms. The effective use the replication technique involves several problems, in relation with the problem of the coherence maintenance of replicas. Our contribution consists new service for the consistency management in the data grid. This service combines between pessimistic and optimistic approaches, taking into account benefits of both approaches, to find a compromise between performance and quality. In addition, our service has been extended by a mechanism placement of replicas based on economics model.     

The existence and synchronization properties of symmetric fix-free codes

Fix-free codes are a type of variable length codes with both prefix-free and suffix-free properties, and there are two types of fix-free codes： symmetric fix-free codes and asymmetric fix-free codes. In this paper, we mainly discuss symmetric fix-free codes. First, the existence of symmetric fix-free codes is studied in detail, and some necessary and sufficient conditions are proposed. We also discuss the problem of achieving synchronization of symmetric fix-free codes, which is important in application. We then establish a scheme with synchronizing codewords to resolve this problem.     

Terrain trafficability simulation of the 4-axel off-road vehicle

In order to estimate the terrain trafficability of the 4-axel off-road truck, the 2D plain stress FEM tire model is constructed and the constitutive equation of the viscoelasticity elements is derived. After analyzing the spring-damper model of the suspension, the 9-DOF model of the off-road truck is presented. With the Lagrange dynamics method, the differential algebraic equations are completed and the gear method is employed to resolve the DAES. Under the actual parameters, the terrain trafficability simulation of the 4-axel off-road truck is carried out. The simulation results of the truck climbing the hillock show that the really ground clearance is 0.48 m and the interference area is specified.     

Development of CAPP tools system based on the derivative and retrieved

Making a CAPP system which has both practicality and versatility is still a problem to be solved. Aiming at this problem, an idea of developing an integrated derivative and retrieved type of CAPP tool system is presented, and combined with a development practice. The structure and key technologies of the system are also introduced.     

Methods for obtaining CIR based on IFFT in MIMO-OFDMA mobile communication systems

This paper mainly focuses on methods for obtaining the CIR by performing the IFFT of CFR, which are heuristic or direct to improve channel estimation and tracking in MIMO-OFDMA systems. When FUSC mode is used, pilot signal are uniformly inserted into the carrier sets during preamble and the FFT size over pilots spacing is an integer in mobile WiMAX. Therefore, it is possible to obtain CPR based on IFFT of CFR. In this paper, we propose two methods involved in IFFT to get CIR, and the size of FFT used by method-1 is smaller than that done by method-2 however, method- 1 has to consider the problem about the offset of pilot carriers.     

Color image recognition method based on the prewitt operator

A method of extracting the target image edge combined with digital image recognition technology is discussed. The prewitt algorithm is employed to detect the edge boundary of the given color image and the quadtree segmentation technique is employed to cut down the storage cost of identification codes. The edge information of color images is exploited to design the identification codes. This method can be used to verify the integrity of the color images by detecting the modified areas of the color images. The experiment results show that the method can locate and extract the modified areas of the color images, operate easily and has well practicability.     

Multi-agent based virtual environment and its application

Most existing researches on virtual environment in mining industry are mainly concentrated on the geometric presentation to create immersive experiences and little attention has been paid on system modeling and formal specification. This paper focuses on modeling methodology of coalmine virtual environment （CMVE） and its application in underground mine safety. A hierarchical architecture model for CVME was present based on multi-agent technology. The proposed model consists of hardware, network and operating system layer, geometric and physical layer, multi-agent layer and man-machine interface layer, and has distinctive features such as reusability, reconfigurability, scalability, intelligence and interactivity. To make multi-agent based CMVE framework more precise, related concepts and agent properties were formally defined. In addition, the design method of typical agent was also discussed and a virtual miner model was built. Finally, an application system for behavior simulation of underground mine safety was introduced. The case system achieves interactive control of virtual environment and fully indicates the capability of producing effective virtual environment for behavior simulation of underground mine safety.     

Cyclic autocorrelation based blind OFDM detection and identification for cognitive radio

Cognitive radio is considered as a promising technique to increase the utilization of limited spectral resource. The key issue in cognitive radio is to design a reliable spectrum sensing method that is able to detect the signal in the target channel as well as to recognize different signals. In this paper, focusing on classifying different OFDM signals, we propose a two-step detection and identification approach. The key parameters to separate different OFDM signals are the subcarrier spacing and guard interval. A simple but reliable peak detection method is adopted in the first step, while a peak searching method is used to determine the length of guard interval. Simulations are carried out in AWGN to verify the validation of the proposed method. It is shown that our method can satisfy the detection and identification requirement with a low false alarm probability.     

A fast calculation strategy of density function in ISAF reconstruction algorithm

The ISAF reconstruction algorithm is a new method for reconstructing icosahedral molecules from their projections. This algorithm works in spherical coordinate system and can achieve higher resolution than the traditional Fourier-Bessel algorithm in cylindrical coordinate system; however this method needs huge computations, which limits its application in reality. The main bottleneck lies in the calculation of density function as it occupies 90% running time of the whole algorithm. A fast calculation strategy of density function is proposed to solve this problem. This strategy is composed of three components： the fast calculation method of density function of mesh point in spherical coordinate system, the transformation method of density function of mesh point from spherical coordinate system to Cartesian coordinate system and the fast two-phase mapping method. The time complexity of calculating density function is decreased from O[（LM）8] to O[（LM）7] in our strategy. The experimental results on Psv-F simulated data indicate that the speed of calculating density function is increased almost two orders of magnitude and the speedup of the whole algorithm could reach 30 times. In addition, the speedup could go up with the increase in the number of images and the requirement of accuracy.     

Approximate Poisson disk sampling on mesh

Poisson disk sampling has been widely used in many applications such as remeshing, procedural texturing, object distribution, illumination, etc. While 2D Poisson disk sampling is intensively studied in recent years, direct Poisson disk sampling on 2-manifold surface is rarely covered. In this paper, we present a novel framework which generates approximate Poisson disk distribution directly on mesh, a discrete representation of 2-manifold surfaces. Our framework is easy to implement and provides extra flexibility to specified sampling issues like feature-preserving sampling and adaptive sampling. We integrate the tensor voting method into feature detection and adaptive sample radius calculation. Remeshing as a special downstream application is also addressed. According to our experiment results, our framework is efficient, robust, and widely applicable.     

Parallel solution for finite element linear systems of equations on workstation cluster

With the advances in the high speed computers network technologies, a workstation cluster is becoming the main environment for parallel processing. Finite element linear systems of equations are common throughout structural analysis in Civil Engineering. The preconditioned conjugate gradient method （PCGM） is an iterative method used to solve the finite element systems of equations with symmetric positive definite system matrices. In this paper, the algorithm of PCGM is parallelized and implemented on DELL workstation cluster. Optimization techniques for the sparse matrix vector multiplication are adopted in programming. The storage scheme is analyzed in detail. The experiment result shows that the designed parallel algorithm has high speedup and good efficiency on the high performance workstation cluster. This illustrates the power of parallel computing in solving large problems much faster than on a single processor.