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.     

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.     

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.     

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.     

Finger Braille teaching system-teaching of prosody of finger Braille

Finger Braille is one of tactual communication media of deaf-blind people. Deaf-blind people who are skilled in Finger Braille can catch up with speech conversation, because of prosody of Finger Braille. Features of prosody are： （1） characters at the end of clauses are dotted long; （2） characters of voiced sounds and double consonants are dotted shortly. In this paper, we designed three teaching patterns which taught prosody of Finger Braille （dot conditions about duration of dotting）. Teaching pattern 1 indicated a dot pattern with colored solid background. Teaching pattern 2 indicated a dot pattern with colored empty background. Teaching pattern 3 indicated a dot pattern with colored arrow （long or short）. Every teaching pattern includes 6 colors （red, orange, yellow, green, blue and purple）. In the questionnaire, the yellow pattern of teaching pattern 3 was selected as the most visible pattern. In the evaluation experiment, the yellow pattern of teaching pattern 3, the red and purple patterns of teaching pattern 1 （the least visible pattern） and the existing patterns without teaching of dot conditions are compared. As a result, every subject could dot long at the end of clauses and could dot shortly at the voiced sounds and double consonants. The answers of questionnaire indicated that the yellow pattern of teaching pattern 3 was also the most visible and easiest teaching pattern.     

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.     

Cluster synchronization of a class of multi-agent systems with a bipartite graph topology

This paper investigates cluster synchronization of a class of multi-agent systems with a directed bipartite graph topology,and presents a number of new results by using the neighbor’s rules for the following two cases:I)there is competition among the agents of diferent clusters,and II)there are both competition and cooperation among the agents.Firstly,for case I),a linear control protocol is designed for cluster synchronization of multi-agent systems,and a method is presented to determine the final state with the initial conditions based on state-space decomposition.Secondly,we study case II),and design a control protocol based on the information of neighbors and that of two-hop neighbors(that is,neighbors’neighbors).Finally,two examples are studied by using our presented results.The study of illustrative examples with simulations shows that our results as well as designed control protocols work very well in studying the cluster synchronization of this class of multi-agent systems.     

Low-power high-speed interconnection networks in NOC using multi-valued current-mode techniques

With the fast developments and growth of electronic applications and a great demand for increasing the speed of processors, VLSI circuits and on-chip interconnections the ＂Networks-On-Chip＂ （NOC） is the best solution for ＂System-On-Chip＂ （SOC）. The most fundamental part of networks On-Chip is the On-Chip interconnection. The model presented in this article describes the method of sending data on On-Chip interconnection by using a current-mode multi-valued logic instead of voltage-mode in order to increase speed and reduce the number of interconnection wires.     

Common Table Expression： Different database systems approach

One of the most recent features in a database is the Common Table Expressions （CTE）, introduced by SQL Server 2005. Microsoft SQL Server 2008 is the second version of SQL Server that supports recursive queries and implements a standard recursive CTE. CTEs are new constructs that offer a more readable form of the derived table that can be declared once and referenced multiple times in a query. Moreover, CTEs can be recursively defined, allowing a recursive entity to be enumerated without the need for recursive-stored procedures. This paper proposes an incursion in the world of Common Table Expression, in order to find its features, its advantages and disadvantages. Also, this paper presents a comparison of performance tests performed on different database systems （SQL Server 2005, SQL Server 2008 and PostgreSQL Server 8.4 Development Version） using similar structures.     

Robust first two rounds access driven cache timing attack on AES

The memory cache data access time uncertainty and resource multi-process sharing mechanism provide a new covert channel to leak process secret information. The AES software implementation uses many table lookup operations to access cache, and these lookup indices have close relationship with the secret key. According to 128-bit AES, we propose a new robust first two rounds access driven cache timing attack. We use a spy process to gather cache access patterns of AES process, thus get the table lookup indices during one AES encryption, combine certain analysis methods, finally recover 128-bit full AES key. With counter to current belief, our experiments show that, only through the first round attack, 350 samples are enough to recover full AES key. After we extend the attack to the second round, 80 samples are enough to recover full AES key.