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.

This paper presents series of experimental studies on newly developed basalt fiber reinforced polymer (FRP) grids forthe flexural strengthening of reinforced concrete beams. The study includes tensile behavior of the basalt FRP grids withthree types of thickness, bonding behavior between the basalt FRP grids and the concrete with epoxy resin, and flexuralbehavior of the reinforced concrete beams strengthened with basalt FRP grids. The results revealed that the modulus ofelasticity of the basalt FRP grids ranged between 40 and 43 GPa, and their tensile strength ranged between 815 and931 MPa. The bond stress–slip behavior of the basalt FRP grids and concrete exhibited a ductile failure manner incomparison to that of FRP sheets and concrete; the bond strength of the tested basalt FRP grids was in the range of3.26–6.06 MPa, and its slip at peak ranged between 0.15 and 0.4 mm. Beams strengthened with basalt FRP grids failed bycrushing of compressive concrete or fiber reinforced polymer rupture and no debonding failure was observed for any ofthe tested beams.

This paper presents series of experimental studies on newly developed basalt fiber reinforced polymer (FRP) grids forthe flexural strengthening of reinforced concrete beams. The study includes tensile behavior of the basalt FRP grids withthree types of thickness, bonding behavior between the basalt FRP grids and the concrete with epoxy resin, and flexuralbehavior of the reinforced concrete beams strengthened with basalt FRP grids. The results revealed that the modulus ofelasticity of the basalt FRP grids ranged between 40 and 43 GPa, and their tensile strength ranged between 815 and931 MPa. The bond stress–slip behavior of the basalt FRP grids and concrete exhibited a ductile failure manner incomparison to that of FRP sheets and concrete; the bond strength of the tested basalt FRP grids was in the range of3.26–6.06 MPa, and its slip at peak ranged between 0.15 and 0.4 mm. Beams strengthened with basalt FRP grids failed bycrushing of compressive concrete or fiber reinforced polymer rupture and no debonding failure was observed for any ofthe tested beams.

A fundamental understanding of the mechanical properties and the failure mechanism of hybrid fiber-reinforced polymers (FRP) is required for the effective application of FRP in construction. This paper presents a new methodology for predicting the tensile behavior of hybrid FRP tendons by considering the interfacial stress transfer between the resin and the fibers in hybrid FRP. Subsequently, the authors utilize the fundamental concepts of fracture mechanics to derive a model capable of predicting the mechanical properties of hybrid FRPs. For this paper, the authors conducted an experimental study on the tensile properties of hybrid basalt/carbon FRP tendons and hybrid glass/carbon FRP tendons. They identified the effects of resin type, fiber fraction, and fiber arrangement over the cross section. The results show that the stress-strain relationship of hybrid FRP can be modified from the linear behavior of FRP to a ductile behavior with a steady pseudoyielding plateau and a high ultimate failure strain. Meanwhile, the load drop in hybrid FRP, which is attributable to the fracture of the fibers with low elongation capacity, can be controlled effectively by the proper design of the hybrid fiber proportions, resin type, and volume fraction. The proposed hybridization results in improving the deformation ability of fibers with low elongation capacity. Moreover, the proposed model for the description of failure progression and prediction of mechanical properties is verified by good agreement with the experimental results of this paper and those from prior studies by others.

Many past researchers have ignored the multi-objective nature of the transit route network design problem (TrNDP), recognizing user or operator cost as their sole objective. The main purpose of this study is to identify the inherent conflict among TrNDP objectives in the design process. The conventional scheme for transit route design is addressed. A route constructive genetic algorithm is proposed to produce a vast pool of candidate routes that reflect the objectives of design, and then, a set covering problem (SCP) is formulated for the selection stage. A heuristic algorithm based on a randomized priority search is implemented for the SCP to produce a set of nondominated solutions that achieve different tradeoffs among the identified objectives. The solution methodology has been tested using Mandl's benchmark network problem. The test results showed that the methodology developed in this research not only outperforms solutions previously identified in the literature in terms of strategic and tactical terms of design, but it is also able to produce Pareto (or near Pareto) optimal solutions. A real-scale network of Rivera was also tested to prove the proposed methodology's reliability for larger-scale transit networks. Although many efficient meta-heuristics have been presented so far for the TrNDP, the presented one may take the lead because it does not require any weight coefficient calibration to address the multi-objective nature of the problem.