Friction compensation of double inverted pendulum on a cart using locally linear neuro-fuzzy model

Double inverted pendulum on a cart (DIPC) is a highly nonlinear system. Due to its complex dynamics, it is widely used as a test-bed plant for the verification of newly designed controllers. In DIPC, two pendulums are kept upward by linear movements of cart. Because of this linear motions and frequent switching of velocity directions, another nonlinearity caused by friction becomes dominant around the equilibrium point. Friction introduces limit cycles to the system and results in a poor steady-state response. To eliminate these negative effects, the locally linear neuro-fuzzy (LLNF) approach is used to build an inverse model for friction compensation. This model is compared with multilayer perceptron network in order to demonstrate the better performance of LLNF. To stabilize DIPC, a common optimal controller is used, and despite its limited performance, experimental results show that the application of inverse modeling for friction compensation improves the steady-state response outstandingly.     

Refractive lens exchange for presbyopia

True presbyopia correction still remains one of the main challenges amongst eye professionals. Many corrective techniques exist including bifocal spectacle correction, monovision techniques both with corrective lenses and surgery, multifocal corneal excimer laser and refractive lens exchange with either accommodating or multifocal lenses. Refractive lens exchange was first described more than 10 years ago and has become more accepted in recent years with advancements in lens technology and improvements in surgical techniques. This article reviews developments in this field and current available lens options in the treatment of presbyopia.     

Study of oil uptake and some quality attributes of potato chips affected by hydrocolloids

The use of coating agents is one effective way to reduce oil absorption in fried products. Reducing the fat content of fried foods by application of coatings is an alternative solution to comply with both health concerns and consumer preferences. The aim of this study was to analyze the effect of hydrocolloids as coating agent on the quantity of oil uptake and on sensory attributes of potato chips. The effect of the coating composition showed that the minimum fat content was related to 1% carboxymethyl cellulose (CMC), 0.5% xanthan, 0.3% guar and 1% xanthan with 21.2, 21.7, 22.4 and 24.8%, respectively, and the highest of fat content was related to blank sample (non-coated), 2% tragacanth, 0.5% guar gum with 49.4, 41.7 and 33.2% of oil content, respectively (p <0.05). The most effective coating agent reduced the oil uptake by 57.03, 55.94, 54.67 and 49.71%, respectively (p <0.05). Sensory evaluation showed that the best color was related to 1% CMC, 0.3% guar and 2% tragacanth, and with respect to flavor evaluation the best flavor was observed in tragacanth 2%, CMC 0.5% and CMC 0.1%, and the best texture referred to tragacanth 2%, CMC 0.5% and CMC 1%. In sensory evaluation, all coated chips got high scores compared with blank (non-coated chips) samples (p <0.05).     

A comparison of Zayandehrood River water values for agriculture and the environment

River water management is challenging not only since they are open systems with changing physical structures, but also because the water values are mostly unknown over varied sectors. If policymakers grasp water values, water management will be more efficient. This research intends to examine the values of water in agriculture, which receives the most substantial portion of water resources, with the values of water in the environment in Isfahan located in the Zayandehrood River basin of Iran. The consequences of contingent valuation and production function methods revealed that per cubic metre value of water is 13 times higher in the environment than agriculture. The government should reconsider the higher value of the environment despite it is a non‐market value. The contingent valuation model additionally proved that women exhibited 21% more willingness to pay than men in order to protect the environment; however, they are paid less by 36%.     

Seismic geomorphology and stratigraphic trap analyses of the Lower Cretaceous siliciclastic reservoir in the Kopeh Dagh-Amu Darya Basin

Lower Cretaceous Shurijeh–Shatlyk Formations host some of the main reservoirs in the Kopeh Dagh-Amu Darya Basin.Exploration in this area so far has focused on the development of structural traps, but recognition of stratigraphic traps in this area is of increasing importance. Integration of 3D seismic data with borehole data from thirteen wells and five outcrop sections was used to identify potential reservoir intervals and survey the hydrocarbon trap types in the East Kopeh Dagh Foldbelt(NE Iran). Analyses of horizontal slices indicated that the lower Shurijeh was deposited in a braided fluvial system.Generally, three types of channel were identified in the lower Shurijeh Formation: type 1, which is low-sinuosity channels interpreted to be filled with non-reservoir fine-grained facies; type 2, which is a moderately sinuous sand-filled channel with good prospectively; and type 3, which is narrow, high sinuosity channel filled with fine-grained sediments. Results indicate that upper Shurijeh–Shatlyk Formations were deposited in fluvial to delta and shallow marine environments. The identified delta forms the second reservoir zone in the Khangiran Field. Study of the stratigraphic aspects of the Shurijeh succession indicates that both lower and upper Shurijeh reservoirs are stratigraphic reservoir traps that improved during folding.     

Quality of service‐aware approaches in fog computing

In recent years, fog computing, a novel paradigm, has emerged for location and latency‐sensitive applications. It is a powerful complement for cloud computing that enables provisioning services and resources outside the cloud near the end devices. In a fog system, the existence of several nonhomogenous devices, which are potentially mobile, led to quality of service (QoS) worries. QoS‐aware approaches are presented in various parts of the fog system, and several different QoS factors are taken into account. In spite of the importance of QoS in fog computing, no comprehensive study on QoS‐aware approaches exists in fog computing. Hence, this paper reviews the current research used to guarantee QoS in fog computing. This paper investigates the QoS‐ensuring techniques that fall into three categories: service/resource management, communication management, and application management (published between 2013 and October 2018). Regarding the selected approaches, this paper represents merits, demerits, tools, evaluation types, and QoS factors. Finally, on the basis of the reviewed studies, we suggest some open issues and challenges which are worth further studying and researching in QoS‐aware approaches in fog computing.     

Deep learning-based visual crack detection using Google Street View images

Neural Computing and Applications - In this study, the utility of using Google Street View (GSV) for evaluating the quality of pavement is investigated. A convolutional neural network (CNN) is...     

Gum arabic–acrylic superabsorbing hydrogel hybrids: Studies on swelling rate and environmental responsiveness

The swelling rate and the environmental sensitivity of novel superabsorbent gum arabic–acrylic hydrogel hybrids were investigated. The swelling kinetics of the hydrogel hybrids was studied by means of a Voigt‐based viscoelastic model. The effects of concentration of the initiator, crosslinker, and the monomer ratio on the swelling rate were studied. The superswelling properties of the hydrogel hybrids were evaluated in various environmental pH, salinity and solvent–water mixtures. The optimally prepared hydrogel, MR5, showed a reproducible on–off switching behavior when the swelling medium was alternatively changed between distilled water and alkaline solutions. The hydrogel hybrid MR5 was also tested to be swollen and deswollen alternatively in distilled water and sodium chloride solution. The sorption–desorption behavior was found to be quite repeatable. A similar capability was interestingly observed when a calcium chloride solution with the same molar concentration was used. The swelling changes of the hydrogel hybrid were examined in various water–solvent systems including the aqueous solutions of methanol, ethanol, acetone, ethylene glycol, glycerol, and dimethylsulfoxide. One and/or two volume‐phase transitions were induced by the nonsolvents. The transitions were explained according to the solubility parameters of the solvents and water–solvent mixtures. The swelling–deswelling capability of the hydrogel in alternatively changed solvent–water mixtures was also studied. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 5667–5674, 2006     

Optimized formulation of an oxidative curing system for liquid polysulfide sealants used in fuel tanks by D‐optimal design method

In this work, the effective parameters in liquid polysulfide curing system were optimized by D ‐optimal design method. Five main components in the formulation, carbon black, vulcanizing agents (MnO₂, Na₂Cr₂O₇, and PbO₂), CaCO₃, fumed silica, and chlorinated paraffin, were selected. Mechanical and chemical properties of the samples were investigated. The results showed that tensile strength, hardness, viscosity, and optimum cure time (t₉₀) presented a suitable coordination with reduced quadratic model. For elongation at break and swelling tests, reduced two‐factor interaction (2FI), and for peel strength, a linear model showed the best correlation. To achieve the desirable properties for liquid polysulfide sealants used in fuel tanks, an optimized amount of the above components in the formulation were used. Finally, MnO₂ curing system, compared with Na₂Cr₂O₇ and PbO₂, was selected as the best choice. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

Surface-Active Properties of Solvent-Extracted <Emphasis Type="Italic">Panax ginseng</Emphasis> Saponin-Based Surfactants

In this study, saponins were extracted from Panax ginseng root powder. The crude solvent‐extracted saponins containing triterpenoid glycosides and terpenes that were identified by TLC techniques. The critical micelle concentrations (CMC) of the saponins were determined by measuring the change in (a) the UV‐visible spectrum of iodine due to the micelle‐iodine complexation, (b) the absorption intensity of aqueous alpha‐lipoic acid due to the micellar solubilization of the drug, and (c) the surface tension due to the abrupt change in the air/liquid interface saturation by surfactants monomers. The development of new absorption peak due to the micelle‐iodine complexation, enhancement in the absorbance due to the micelle‐solubilized lipoic acid, and displacement of monomer‐micelle equilibrium to micelle formation in higher monomer concentration region are some of the physicochemical properties in which CMC could be determined. We found a CMC of 0.009% w/v.