Image watermarking, authentication and encryption have gained an increased importance during the last decade. This is due to the widespread use of visual media over the Internet and in several digital media applications. Several watermarking techniques have been proposed, some in spatial domain, and more recently in the transform/frequency domain and have been reported to be robust against different attacks, namely compression. It is also well known the importance and effectiveness of compression techniques to store transmit and retrieve visual information. However, the creation or development of a joint watermarking and compression framework for images has yet to be explored, where watermarking and compression could be pursued jointly on a trade-off manner. In other words, watermarking embedding/extraction can be performed on compressed domain data, while compression parameters could be used as watermarking keys. The primary focus of this paper is to explore this novel/unique idea. We propose a joint watermarking and compression (JWC) technique in the transform domain. This transform domain is based on the Natural Preserve Transform and can be utilized to achieve a balance between watermarking and compression for visual information. Watermarking performance is evaluated blindly for different compressed domain data scenarios, while compression performance is analyzed for other watermarking cases. Extensive simulation results that demonstrate the efficiency of the proposed joint watermarking and compression technique are presented.

E-splines (Exponential spline) polynomials represent the best smooth transition between continuous and discrete domains. As they are constructed from convolution of exponential segments, there are many degrees of freedom to optimally choose the most convenient E-spline, suitable for a specific application. In this paper, the parameters of these E-splines were optimally chosen, to enhance the performance of image zooming and interpolation schemes. The proposed technique is based on minimizing the total variation function of the detail coefficients of the E-spline based wavelet decomposition. In zooming applications, the quality of interpolated images are further improved and sharpened by applying ICA technique to them, in order to remove any dependency. Illustrative examples are given to verify image enhancement of the proposed E-spline scheme, when compared with the existing approaches.

Secondary flows are noxious to axial compressor performance. To overcome and control those secondary flows, vortex generators are used as a passive control device. Controlling secondary flows will lead to a further improvements in the compressor performance. A new design of vortex generator is considered in this investigation in order to control secondary flows in axial compressor cascade at design and off-design conditions. Numerical simulations of a three-dimensional compressible turbulent flow have been performed to explore the effect of the vortex generators on the reduction of secondary flows. Six different incidence angles are used for the off-design operation investigations. Based on the simulation results, the pressure, velocity, and streamline are used to follow up the development of the secondary flows. Thence, total pressure loss coefficient, static pressure rise coefficient, difference in flow deflection angle, and diffusion factor are estimated. Results indicate that vortex generators have a significant effect on the development of secondary flows at off design operation as they cause a reduction in total pressure loss, they also affect the loading behavior of the cascade as they cause a slight change in the cascade deflection, and a slight decrease in the diffusion factor which causes unloading of the blade. Static pressure rise is significantly reduced at negative incidence angles while a slight reduction occurs at positive incidence angles. In a word, the new design of the vortex generator enhances the cascade aerodynamic performance and enlarges the operating range of the cascade towards the positive incidence region.

Many forensic techniques recently tried to detect the tampering and manipulation of JPEG compressed images thatbecame a critical problem in image authentication and origin tracking. Some techniques indicated that a knowledgeable attacker can make it very hard to trace the image origin, while others indicated that portions of the compressed image that has been compressed at different quality factor quantization matrices are distinguishable if they are re-compressed at a higher quality factor quantization matrix (with less quantization steps). In this paper we propose the idea of adopting Integer DCT (ICT) as an implementation technique that can be utilized in the detection of any hacking or tampering of JPEG/ICT compressed images. The proposed approach is based upon recent literature ideas of recompressing JPEG image blocks and detecting if this block has been compressed/touched before or not. We also propose an ICT implementation that has a onetime signature on processed coefficients or pixels and can be used as a tool to detect if this block has been compressed before using the proposed implementation or not. We finally propose to re-compress images originally compressed with ICT but with a different quantization matrix as a different compression parameter to analysis and detect more forgeries. Illustrative examples on several processed images are presented with complexity analysis.

B-splines caught interest of many engineering applications due to their merits of being flexible and provide a large degree of differentiability and cost/quality trade off relationship. However they have less impact with continuous time applications as they are constructed from piecewise polynomials. On the other hand, Exponential spline polynomials (E-splines) represent the best smooth transition between continuous and discrete domains as they are made of exponential segments. In this paper we present a complete analysis for an E-spline based subband coding (wavelet) perfect reconstruction (PR) system. Derivations for the scaling and wavelet functions are presented, along with application of the proposed system in image compression and image denoising. In image compression, a comparison of the proposed technique compared with the B-spline based PR system as well as the basic wavelet subband system with the SPIHT image codec, is presented. In image denoising, we report the enhancement achieved with the proposed E-spline based denoising approach compared with B-spline based denoising and another basic denoising technique. In both applications, E-splines show superior performance as will be illustrated.

B-splines caught interest of many engineering applications due to their merits of being flexible and provide a large degree of differentiability and cost/quality trade off relationship. However they have less impact with continuous time applications as they are constructed from piecewise polynomials. On the other hand, Exponential spline polynomials (E-splines) represent the best smooth transition between continuous and discrete domains as they are made of exponential segments. In this paper we present a complete analysis for an E-spline based subband coding (wavelet) perfect reconstruction (PR) system. Derivations for the scaling and wavelet functions are presented, along with application of the proposed system in image compression and image denoising. In image compression, a comparison of the proposed technique compared with the B-spline based PR system as well as the basic wavelet subband system with the SPIHT image codec, is presented. In image denoising, we report the enhancement achieved with the proposed E-spline based denoising approach compared with B-spline based denoising and another basic denoising technique. In both applications, E-splines show superior performance as will be illustrated.

This study investigates the effectiveness and feasibility of a prestressed carbon fiber-reinforced polymer (CFRP) system and prestressed glass fiber reinforced polymer (GFRP) system for strengthening reinforced concrete (RC) beams. The proposed prestressing system with a novel anchorage allows the utilization of the full capacity of the sheets. Five small-scale, six small scale and four large-scale concrete beams strengthened with different configuration of prestressed CFRP and GFRP sheets are tested under static loading conditions up to failure. The main parameters considered include the level of prestressing applied, ranging from 23% to 60% of the tensile strength of the CFRP sheets, using of mechanical anchorages at both ends of the CFRP sheets. Thanks to the durable anchorage, the full range of flexural behavior was investigated, including post-debonding, comparison of strengthening using CFRP and GFRP, size effect in flexure of prestressed concrete beams and difference between the flexure capacities of beams which strengthened precracked and other strengthened at cracked region. The results indicate that the beams strengthened using prestressed CFRP and GFRP sheets exhibited a higher first-cracking, steel-yielding, and experimental nominal moments as the level of prestressing force increased up to a certain point.

This study investigates the effectiveness and feasibility of a prestressed carbon fiber-reinforced polymer (CFRP) system and prestressed glass fiber reinforced polymer (GFRP) system for strengthening reinforced concrete (RC) beams. The proposed prestressing system with a novel anchorage allows the utilization of the full capacity of the sheets. Five small-scale, six small scale and four large-scale concrete beams strengthened with different configuration of prestressed CFRP and GFRP sheets are tested under static loading conditions up to failure. The main parameters considered include the level of prestressing applied, ranging from 23% to 60% of the tensile strength of the CFRP sheets, using of mechanical anchorages at both ends of the CFRP sheets. Thanks to the durable anchorage, the full range of flexural behavior was investigated, including post-debonding, comparison of strengthening using CFRP and GFRP, size effect in flexure of prestressed concrete beams and difference between the flexure capacities of beams which strengthened precracked and other strengthened at cracked region. The results indicate that the beams strengthened using prestressed CFRP and GFRP sheets exhibited a higher first-cracking, steel-yielding, and experimental nominal moments as the level of prestressing force increased up to a certain point.

This study investigates the effectiveness and feasibility of a prestressed carbon fiber-reinforced polymer (CFRP) system and prestressed glass fiber reinforced polymer (GFRP) system for strengthening reinforced concrete (RC) beams. The proposed prestressing system with a novel anchorage allows the utilization of the full capacity of the sheets. Five small-scale, six small scale and four large-scale concrete beams strengthened with different configuration of prestressed CFRP and GFRP sheets are tested under static loading conditions up to failure. The main parameters considered include the level of prestressing applied, ranging from 23% to 60% of the tensile strength of the CFRP sheets, using of mechanical anchorages at both ends of the CFRP sheets. Thanks to the durable anchorage, the full range of flexural behavior was investigated, including post-debonding, comparison of strengthening using CFRP and GFRP, size effect in flexure of prestressed concrete beams and difference between the flexure capacities of beams which strengthened precracked and other strengthened at cracked region. The results indicate that the beams strengthened using prestressed CFRP and GFRP sheets exhibited a higher first-cracking, steel-yielding, and experimental nominal moments as the level of prestressing force increased up to a certain point.

In this paper, optimization scheme for microgrids is presented. In microgrids, the operational cost and greenhouse gas emissions are mainly depend on types and sizes of distributed generators (DGs) used. This paper aims to reduce the operational cost and the greenhouse gas emissions through evaluating the optimal output of each DG type. DGs operate within their respective capacity limits while satisfying the local energy demand (both electrical and thermal). The multi-objective optimization compromises between the operational cost and the emissions. The constraints include power and heat demands constraints, and DG capacity limits.