Design,Modeling and Control of a Simulator of an Aircraft Maneuver in the Wind Tunnel Using Cable Robot

International Journal of Control, Automation and Systems - In this paper, a new controllable simulator is proposed and modeled by which, experimental tests of the aircraft’s models can be...     

Analytical design of optimal trajectory with dynamic load-carrying capacity for cable-suspended manipulator

This paper describes the development of an approach for trajectory planning of cable-suspended parallel robots using optimal control approach. A prototype has been built, and tests have been carried out to verify the theoretical results. This paper briefly illustrates this device and presents some initial tests. The final dynamic equations are organized in a closed form similar to serial manipulator equations. Dynamic load-carrying capacity problem is converted into a trajectory optimization problem which is fundamentally a constrained nonlinear optimization problem. The problem is formulated using optimal control theory, and the ideas are analyzed using Pontryagin’s minimum principle. The optimal solutions are found by solving the corresponding nonlinear two-point boundary value problems. The main objective is to find the manipulator load-carrying capacity in point-to-point task by considering actuator torque while cable forces are positive.     

Rural domestic water consumption behavior: A case study in Ramjerd area, Fars province, I.R. Iran

Identifying the factors that affect domestic water demand and consumption is very important in management of available regional water resources. In this study, relationships between water consumption and rural household activities are determined by comparing a snapshot of water consumption with rural household behavior of low, medium and high water consumers. In addition, the factors affecting water consumption in rural households are also determined. The data for this study were collected from a survey of 653 rural households in 33 villages of Ramjerd area, Fars Province, in southern Iran, using a simple random sampling technique. The daily water consumption data for a 5-year period (1999-2004) were used. Results of the study revealed that the daily average water consumption for the area was found to be 121.7 l per person per capita per day (Lpcd) (SD=59.2). Water consumption was also found to be significantly correlated with explanatory variables such as “household size” and “age of household's head”. Finally, the results of discriminant function analysis showed that in rural households, garden size, greenhouse size, and garden watering times per month with tap treated water are associated with water consumption.     

HYBRID GENETIC PROGRAMMING-BASED SEARCH ALGORITHMS FOR ENTERPRISE BANKRUPTCY PREDICTION

Bankruptcy is an extremely significant worldwide problem that affects the economic well- being of all countries. The high social costs incurred by various stakeholders associated with bankrupt firms imply the need to search for better theoretical understanding and prediction quality. The main objective of this paper is to apply genetic programming with orthogonal least squares (GP/OLS) and with simulated annealing (GP/SA) algorithms to build models for bankruptcy prediction. Utilizing the hybrid GP/OLS and GP/SA techniques, generalized relationships are obtained to classify samples of 136 bankrupt and nonbankrupt Iranian corporations based on financial ratios. Another important contribution of this paper is to identify the effective predictive financial ratios based on an extensive bankruptcy prediction literature review and a sequential feature selection (SFS) analysis. A comparative study on the classification accuracy of the GP/OLS- and GP/SA-based models is also conducted. The observed agreement between the predictions and the actual values indicates that the proposed models effectively estimate any enterprise with regard to the aspect of bankruptcy. According to the results, the proposed GP/SA model has better performance than the GP/OLS model in bankruptcy prediction.     

Thermal performance analysis of arbitrary-profile fins with non-fourier heat conduction behavior

The thermal performance of variable cross-section fins is considered using the Maxwell–Cattaneo–Vernotte (MCV) heat conduction model. Four different fins, namely rectangular, triangular, convex, and concave fins, with a periodic thermal condition are examined. The governing equations are hyperbolic and are solved numerically using an implicit finite difference method. In the MCV model, the thermal wave propagates with a finite speed, and hence sharp discontinuities appear in the temperature profiles. In this study, temperature profiles at various times, heat transfer rates, and thermal efficiencies of Fourier and non-Fourier fins are presented. In addition, the effect of relaxation time is considered. The results show that the effects of cross-sectional area and relaxation time are considerable on the thermal performance of various non-Fourier fins. To validate our findings, the results for non-Fourier fins with constant cross-sectional area obtained from this study are compared to those of other numerical solutions. This comparison confirms the correctness of the current results.     

A gold nanoparticle platform for protein-protein interactions and drug discovery

Gold nanoparticles hold great promise for studying protein-protein interactions because of their intrinsic optical properties. Pink when in a homogeneous suspension, the solution turns blue-gray when particles are drawn close together, for example, when immobilized proteins specifically interact with each other. However, the nanoparticle stability, size, and method of protein attachment contribute to the unreliable outcome of current assays. To overcome these hurdles, we developed novel and reliable methods first to synthesize homogenous particles of optimal diameter and second to apply a heterologous NTA-Ni-SAM coating for controlled orientation and optimal presentation of histidine-tagged proteins. Both methods were proven to greatly enhance assay sensitivity and specificity by increasing the signal and minimizing the nonspecific binding. Our assay reproducibly detected known protein-protein interactions and unambiguously identified small molecules that inhibited them. We believe our gold nanoparticle bioassay is a versatile and trustworthy new platform for analyzing protein-protein interactions and high-throughput screening of small-molecule inhibitors.     

Flow along and across glass‐fiber wicks: Testing of permeability models through experiments and simulations

A rigorous test of important theoretical models for permeability of glass‐fiber wicks, backed by numerical simulations, is conducted using a novel small‐scale experiment. The models include those for flow along and across aligned fibers and for flow through random fibers. The domains for numerical simulations were created by randomly distributed parallel fibers in a cube‐like unit‐cell using Geodict. Two separate simulations were considered: (1) Stokes‐flow solution using GeoDict, (2) Whitaker's closure‐formulation solution using COMSOL. The falling‐head parameter was adapted to measure the permeability along and across the fibers. Multiple measurements were conducted for each of the wicks to establish repeatability and estimate scatter. The permeabilities obtained through experiments matched with those from the theoretical and numerical methods. But numerical permeabilities for the longitudinal flow were exceptionally accurate. Also, the specialized models for longitudinal and transverse flows were more accurate than the random‐fiber models. © 2018 American Institute of Chemical Engineers AIChE J, 64: 3491–3501, 2018     

Evaluation of power plants to prioritise the investment projects using fuzzy PROMETHEE method

Increasing population growth of Iran, and consequently, increasing the annual energy consumption has made the construction of more than 3000?MW power plant necessary. Taking into account various criteria, some power plants have been evaluated and ranked to select the most appropriate power plant for investment. For this purpose, three aspects and seven main criteria for evaluating power plants have been determined. Afterward, weights of sub-criteria have been determined by Analytical Network Process method, and eventually, power plants have been ranked by a multi-criteria decision-making (MCDM) method (i.e. fuzzy PROMETHEE II). Moreover, a comprehensive sensitivity analysis has been carried. Finally, power plants have been ranked by fuzzy technique for order preference by similarity to ideal solution (TOPSIS) method once again. Since the value of Spearman Correlation Test for two implemented methods is equal to 0.98, it can be concluded that fuzzy PROMETHEE II performs as well as fuzzy TOPSIS in ranking alternatives.