Moisture and heat transfer in hybrid weft knitted fabric with artificial intelligence

One of the most important properties of clothes is their ability to help the body's thermal system to keep the body temperature in its natural range, even if the environmental conditions or physical activities are outside the body's ideal range. Perspiring is one of the most important effects of physical activities in warm weather for shedding the body's excessive heat. Therefore, the basic requirement of a fabric worn next to the skin is to transfer this moisture to the atmosphere to reach comfort through the avoidance of a feeling of wetness and clamminess and also through the generation of a situation for the best surface evaporation of moisture. The main goal of this study was to achieve a kind of fabric that guarantees comfort for the body by good heat and moisture transport. To achieve this goal, a group of double‐surface fabrics containing hydrophilic and hydrophobe fibers were knitted, and their simultaneous heat and moisture transport was evaluated with the help of a perspiration‐simulation machine; the results were analyzed as transfer process plots. Also, the transmission of heat and moisture was evaluated for all of the samples by differential modeling as an artificial neural network. Effective parameters on heat and moisture transfer were taken into consideration with modeling and statistical methods. The results were analyzed to find a suitable fabric with optimum comfort. The final results showed that a fabric made of micropolyester filaments and cotton yarns on the bottom and top surfaces, respectively, had the best heat and moisture transfer. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

A Single Input-Multiple Output Time Reversal UWB Communication System

Time reversal is a promising technique for the improvement of UWB communication systems. Intersymbol interference (ISI) limits the system performance in such wireless systems. This paper presents a general ISI analysis for time reversal UWB communication systems. The time reversal UWB system gives good performance for rates below the coherence bandwidth but at higher data rates the performance of the system is limited by intersymbol interference and bit error rate saturates even for high signal-to-noise ratio. To mitigate the ISI effects, a single input/multiple output (SIMO) time reversal UWB system is used and its performance is analyzed. It is shown that by using a SIMO TR transceiver, ISI reduces and the system capacity increases. Transmitted signal power at SIMO time reversal decreases, therefore in low data rate SISO performance is better than SIMO, But in high rate scenario, SIMO TR suppresses the ISI better than the SISO TR and its performance is better than SISO TR. It is possible to compensate the reduced power by using a receiver with more sensitivity.     

Physical analysis of β-Ga2O3 gate-all-around nanowire junctionless transistors: short-channel effects and temperature dependence

Journal of Computational Electronics - In this study, we analyze a β-Ga2O3 gate-all-around nanowire junctionless transistor (β-GAA-JLT) in accumulation mode. The performances are...     

Formulation of dynamics,actuation, and inversion of a three‐dimensional two‐link rigid body system

In this paper, three issues related to three‐dimensional multilink rigid body systems are considered: dynamics, actuation, and inversion. Based on the Newton‐Euler equations, a state space formulation of the dynamics is discussed that renders itself to inclusion of actuators, and allows systematic ways of stabilization and construction of inverse systems. The development here is relevant to robotic systems, biological modeling, humanoid studies, and collaborating man‐machine systems. The recursive dynamic formulation involves a method for sequential measurement and estimation of joint forces and couples for an open chain system. The sequence can start from top downwards or from the ground upwards. Three‐dimensional actuators that produce couples at the joints are included in the dynamics. Inverse methods that allow estimation of these couples from the kinematic trajectories and physical parameters of the system are developed. The formulation and derivations are carried out for a two‐link system. Digital computer simulations of a two‐rigid body system are presented to demonstrate the feasibility and effectiveness of the methods. © 2005 Wiley Periodicals, Inc.     

Multi-Path Reasoning in a Database

Rules have been used in a database context for several purposes:deductive database queries, active database triggers, and productionsystem programs. Exploring the search space for non-deterministicrule programs, however, has generally been available only in largemonolithic systems intended for artificial intelligence applications.The goal of this research is to provide multi-path reasoning fornon-deterministic rule programs in a database environment. Themotivation for this work includes the increasing use ofdatabase-style triggers to assist data-intensive applications, e.g.,the human genome project and the Intelligent Integration ofInformation (I ³) Program.A non-deterministic rule program is one where there is more than oneterminal state. Such programs are generally not consideredappropriate for database queries where the focus is on rules programsor techniques that guarantee a unique fixed point. Butnon-deterministic programs are commonly used for various heuristicsearch problems such as the traveling salesperson problem. With anon-deterministic program, it is particularly important to beflexible about the order in which the search space is exploredbecause exhaustive search is generally not feasible. Thecontributions of this research are: the representation of themulti-path search tree within a database and the ability for theproblem solver to control the search process for a non-deterministicrule program.     

Violence detection in videos using interest frame extraction and 3D convolutional neural network

Multimedia Tools and Applications - With the rapid development of detecting violent behaviors in surveillance cameras, requests on systems that automatically recognize violent events are expanded....     

Performance assessment of a horizontal-coil geothermal heat pump

This paper evaluates the performance of a geothermal heat pump in Iran. An air-to-air 5.275 kW heat pump has been changed and redesigned to a geothermal heat pump system for the first time in Iran. Air-to-air condenser has been replaced by a tube-in-tube heat exchanger and assembled system has been tested under ARI-325 standard at the national energy lab of Iran and the results have been compared with the original system. Then, local weather conditions and soil properties of Tabriz (located at the north-west of Iran) have been applied and geothermal coil has been designed. Coil has been connected to the heat pump and the average coefficient of performance (COP) of rather more than three has been recorded in cooling mode. Results obtained from experimental measurements show that horizontal GSHP systems can be used for Tabriz-like climates in Iran. Copyright © 2006 John Wiley & Sons, Ltd.     

Stability and a control strategy of a multilink musculoskeletalmodel with applications in FES

Introduces a relegated control strategy for point-to-point movement of musculoskeletal systems driven by redundant actuators. The actuator system is partitioned to two functional groupings referred to as gravity compensators and movement generators. Unlike dynamic optimization methods, relegation of control enables real-time computation of control signals to the muscle actuators. It is shown that this strategy significantly reduces the degree of coactivation needed to stabilize the movement. The real-time nature of this strategy coupled with reduced coactivation makes the proposed strategy amenable for multichannel control of paraplegics through functional electrical stimulation. Simulations of a three-link sagittal system are conducted to test the algorithm for a bowing movement     

The role of Al and Mg in the hydrogen storage of electrospun ZnO nanofibers

Pure and doped ZnO nanofibers with Al and Mg were successfully synthesized via an electrospinning method using a sol–gel containing Polyvinylpyrrolidone as a spinning aid and a zinc nitrate precursor. Calcination of the doped and undoped electrospun nanofibers was conducted at 500 °C in air, and the resultant structures were analyzed by X-ray diffraction (XRD) and Raman spectroscopy. The diameter of the doped nanofibers decreased with increasing viscosity and conductivity, as measured by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Energy dispersive spectroscopy (EDS) showed that Mg and Al are present in ZnO nanofibers. The pressure composition isotherm (PCI) demonstrated that the capacity of hydrogen storage in pure zinc oxide nanofibers is a factor of two greater than that of zinc oxide nanoparticles. However, Al-doped ZnO nanofibers have the highest capacity of hydrogen storage (2.81 wt%) at room temperature.     

Characterization and the hydrogen storage capacity of titania-coated electrospun boron nitride nanofibers

In the present work, titania-coated (TiO₂) boron nitride nanofibers were produced by the electrospinning method, and the effect of heat treatment on the nanofibers was studied. Electrospinning method is often adopted for the synthesis of one-dimensional nanofibers due to high productivity, simplicity, and cost-effectiveness. In this study, boric oxide was deposited on co-electrospun polyacrylonitrile and TiO₂. TiO₂-coated boron nitride nanofibers, with a diameter of 100 nm, were obtained after heat treatment and nitridation. The effects of heat treatment on the morphology, surface area and hydrogen storage capacity were studied extensively. Scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX), and transmission electron microscopy (TEM) showed long, bead-free nanofibers and the presence of TiO₂ nanoparticles on the nanofibers. X-ray diffraction (XRD) and Fourier transform infrared (FTIR) spectroscopy depicted hexagonal structures of boron nitride. The hydrogen uptake capacities of the nanofibers were investigated by pressure composition isotherm (PCI) in the pressure range of 1–70 bar at room temperature.