Modified Cuckoo Optimization Algorithm (MCOA) to solve Precedence Constrained Sequencing Problem (PCSP)

In recent years, new meta-heuristic algorithms have been developed to solve optimization problems. Recently-introduced Cuckoo Optimization Algorithm (COA) has proven its excellent performance to solve different optimization problems. Precedence Constrained Sequencing Problem (PCSP) is related to locating the optimal sequence with the shortest traveling time among all feasible sequences. The problem is motivated by applications in networks, scheduling, project management, logistics, assembly flow and routing. Regarding numerous practical applications of PCSP, it can be asserted that PCSP is a useful tool for a variety of industrial planning and scheduling problems. However it can also be seen that the most approaches may not solve various types of PCSPs and in related papers considering definite conditions, a model is determined and solved. In this paper a new approach is presented for solving various types of PCSPs based on COA. Since COA at first was introduced to solve continuous optimization problems, in order to demonstrate the application of COA to find the optimal sequence of the PCSP, some proposed schemes have been applied in this paper with modifications in operators of the basic COA. In fact due to the discrete nature and characteristics of the PCSP, the basic COA should be modified to solve PSCPs. To evaluate the performance of the proposed algorithm, at first, an applied single machine scheduling problem from the literature that can be formulated as a PCSP and has optimal solution is described and solved. Then, several PCSP instances with different sizes from the literature that do not have optimal solutions are solved and results are compared to the algorithms of the literature. Computational results show that the proposed algorithm has better performance compared to presented well-known meta-heuristic algorithms presented to solve various types of PCSPs so far.     

An overview of the environmental,economic, and material developments of the solar and wind sources coupled with the energy storage systems

There is a constant growth in energy consumption and consequently energy generation around the world. During the recent decades, renewable energy sources took heed of scientists and policy makers as a remedy for substituting traditional sources. Wind and photovoltaic (PV) are the least reliable sources because of their dependence on wind speed and irradiance and therefore their intermittent nature. Energy storage systems are usually coupled with these sources to increase the reliability of the hybrid system. Environmental effects are one of the biggest concerns associated with the renewable energy sources. This study summarizes the last and most important environmental and economic analysis of a grid‐connected hybrid network consisting of wind turbine, PV panels, and energy storage systems. Focusing on environmental aspects, this paper reviews land efficiency, shaded analysis of wind turbines and PV panels, greenhouse gas emission, wastes of wind turbine and PV panels' components, fossil fuel consumption, wildlife, sensitive ecosystems, health benefits, and so on. A cost analysis of the energy generated by a hybrid system has been discussed. Furthermore, this study reviews the latest technologies for materials that have been used for solar PV manufacturing. This paper can help to make a right decision considering all aspects of installing a hybrid system. Copyright © 2017 John Wiley & Sons, Ltd.     

Geometrical and structural setting of landslide dams of the Central Alborz: a link between earthquakes and landslide damming

Bulletin of Engineering Geology and the Environment - The combination of remote sensing observations, geological field investigations and geomorphological mapping and measurements along with faults...     

Effects of Desolvating Agent Types,Ratios, and Temperature on Size and Nanostructure of Nanoparticles from α‐Lactalbumin and Ovalbumin

In this study, we compare the preparation of ovalbumin (OVA) and α‐lactalbumin (α‐LA) nanoparticles using different desolvating agents (ethanol, acetone, and methanol) and water: desolvating agent volume ratios (1:3, 1:4, 1:5, 1:10, and 1:20). Also the effects of protein solution temperature (25, 50, and 80 ℃) on the size of nanoparticles and the stability of crosslinked nanoparticles for 30 d were studied. OVA and α‐LA were shown to be good candidates for nanoparticulation and nanoparticles in the range of 60 to 230 nm were obtained. The comparison between the 2 proteins offers guidance to optimize OVA and α‐LA nanoparticle fabrication and to efficiently obtain nanoparticles with desired characteristics. The particle sizes of OVA nanoparticles were found to be in the range of 60 to 160 nm, and the particle sizes of α‐LA were between 150 and 230 nm. The sizes varied with different desolvating agents: for OVA, ethanol, and methanol both produced nanoparticles smaller than 100 nm; for α‐LA, methanol produced the smallest nanoparticles. Water: desolvating agent ratios, in the studied range, did not show a significant effect on the particle sizes for both OVA and α‐LA nanoparticles. The size and morphology of the nanoparticles were found to change when the protein solutions were heated up to 50 and 80 ℃ and cooled down before nanoparticulation and most nanoparticles had a smaller diameter.     

A convenient solvent-free and one-pot synthesis of 4-hydroxythiazolidine-2-thiones

A highly efficient solvent-free and simple one-pot approach for the synthesis of 4-hydroxythiazolidine-2-thione is described. The reaction of primary amines and carbon disulfide in the presence of 2-chloroacetaldehyde afforded the title compounds in high yields.     

Damage Detection in a Composite Plate Using Modal Analysis and Artificial Intelligence

The use of composite materials has vastly increased in recent years. Great interest is therefore developed in the damage detection of composites using non-destructive test methods. Several approaches have been applied to obtain information about the existence, location and growth of the faults. The main goal in this paper is to use the vibration response of a composite plate to detect and localize delamination defect based on the frequency response and modal analysis. The features extracted are used as the input data in an artificial intelligence scheme to identify the severity of the damages. Experiments are then conducted to validate the developed model.     

Adaptive decoupled control of 4-leg voltage-source inverters for standalone photovoltaic systems: Adjusting transient state response

Three leg inverters for photovoltaic systems have a lot of disadvantages, especially when the load is unbalanced. These disadvantages are for example, small utilization of the DC link voltage, the dependency of the modulation factor of the load current and the superposition of a DC component with the output AC voltage. A solution for these problems is the four-leg inverter. Consequently, generation of balanced voltage with sinusoidal waveform is necessary for these inverters. The power stage model of the 4-leg inverter in rotating coordinates dqo is highly coupled. Consequently, controller design procedure is very difficult and complex. On the other hand, adaptive control for 4-leg inverters has not yet been discussed in the literature. This paper proposes the state feedback approach to decouple the system and convert it to a second-order system which has two poles equal to zero. Then, it suggests a compensator to cancel poles of the closed-loop system and to convert the final system to a desired second-order system. Thanks to use of this strategy the transient performance of the system, such as overshoot and speed of response, becomes greatly adjustable. In addition, an STR (Self-Tuner Regulator) is introduced to tune the state feedback matrix and to guarantee the adaptive performance of the system. Simulation results validate that, by using proposed control strategy, the 4-leg inverter generates balanced voltage, with perfect sinusoidal waveform, in spite of the presence RL time-variant loads.     

Multireference object pose retrieval with volume feedback

Pose retrieval of a rigid object from monocular video sequences or images is addressed. Initially, the object pose is estimated in each image assuming flat depth maps. Shape-from-silhouette is then applied to make a 3-D model (volume), which is used for a new round of pose estimations, this time by a model-based method that gives better estimates. Before repeating this process by building a new volume, pose estimates are adjusted to reduce error by maximizing a novel quality factor for shape-from-silhouette volume reconstruction. The feedback loop is terminated when pose estimates do not change much, as compared with those produced by the previous iteration. Based on a theoretical study of the proposed system, a test of convergence to a given set of poses is devised. Reliable performance of the system is also proved by several experiments on both synthetic and real image sequences. No model is assumed for the object and no feature point is detected or tracked as there is no problematic feature matching or correspondence. Our method can be used for 3-D object tracking in video, 3-D modeling, and volume reconstruction from video.