The effect of uncontrolled concurrency on model checking

Correctness of concurrent software is usually checked by techniques such as peer code reviews or code walkthroughs and testing. These techniques, however, are subject to human error, and thus do not achieve an in‐depth verification of correctness. Model‐checking techniques, which can systematically identify and verify every state that a system can enter, are a powerful alternative method for verifying concurrent systems. However, the usefulness of model checking is limited because the number of states for concurrent models grows exponentially with the number of processes in the system. This is often referred to as the ‘state explosion problem.’ Some processes are a central part of the software operation and must be included in the model. However, we have found that some exponential complexity results due to uncontrolled concurrency introduced by the programmer rather than due to the intrinsic characteristics of the software being modeled. We have performed tests on multimedia synchronization to show the effect of abstraction as well as uncontrolled concurrency using the Promela/SPIN model checker. We begin with a sequential model not expected to have exponential complexity but that results in exponential complexity. In this paper, we provide alternative designs and explain how uncontrolled concurrency can be removed from the code. Copyright © 2007 John Wiley & Sons, Ltd.     

Adsorption of copper(II), cobalt(II), and iron(III) ions from aqueous solutions on poly(ethylene terephthalate) fibers

The adsorption behavior of poly(ethylene terephthalate) (PET) fibers towards copper(II), cobalt(II), and iron(III) ions in aqueous solutions was studied by a batch equilibriation technique. Influence of treatment time, temperature, pH of the solution, and metal ion concentration on the adsorption were investigated. Adsorption values for metal ion intake followed the following order: Co(II) > Cu(II) > Fe(III). One hour of adsorption time was found sufficient to reach adsorption equilibrium for all the ions. The rate of adsorption was found to decrease with the increase in the temperature. Langmuir adsorption isoterm curves were found to be significant for all the ions studied. The heat of adsorption values were calculated as −5, −2.8, and −3.6 kcal/mol for Cu(II), Co(II), and Fe(III) ions, respectively. © 1998 John Wiley & Sons, Inc. J Appl Polym Sci 68: 1935–1939, 1998     

UAV instantaneous power consumption prediction using LR-TCN with simple moving average

The usage of multi-rotor unmanned aerial vehicles (UAVs) has rapidly increased in a variety of industries recently, which has caused a quick rise in the quantity of research works on the topic. Remaining battery life prediction, anomaly detection and instantaneous power consumption prediction are among the topics that attract the most attention of researchers. This article presents the development and utilization of a modified temporal convolutional network (TCN) model, a commonly employed approach for anomaly detection and instantaneous power consumption prediction in unmanned aerial vehicles (UAVs). The first modification to the TCN model was to use the Leaky ReLu activation function in place of the rectified linear unit (ReLu) activation function from the original TCN model. In the next step, instantaneous power consumption prediction for UAVs was performed by using the data obtained from both sensors and simple moving average (SMA) algorithm. As a result of the tests performed with the created simulation setup, it has been clearly shown that the proposed method gives better results compared to other deep learning models used for comparison with the lowest RMSE of 0.0496.     

Polymerization of propylene using a prepolymerized high-active Ziegler–Natta catalyst. I. Kinetic studies

The kinetics of propylene polymerization using a prepolymerized high-active TiCl₃ catalyst with an Et₂AICI cocatalyst are investigated. The effect of various parameters such as AI/Ti ratio, pressure, temperature, hydrogen, and polymerization time on the rate of polymerization and yield are examined. The dependency of these parameters on the polymerization rate are studied. It is found that the variation at the rate of polymerization with the Et₂AICI cocatalyst concentration complies with a Langmuir–Hinshelwood type of relationship. The overall activation energy of polymerization calculated from the Arrhenius plot was found to be 11.6 kcal/mol. © 1996 John Wiley & Sons, Inc.     

Microstructure and Property Relationships in Resistance Spot Weld between 7114 Interstitial Free Steel and 304 Austenitic Stainless Steel

Due to the differences in physical, chemical and mechanical properties of the base metals, the resistance spot welding of dissimilar materials is generally more challenging than that of similar materials. The influence of the primary welding parameters affecting the heat input such as peak current on the morphology, microhardness, and tensile shear load bearing capacity of dissimilar welds between 304 grades austenitic and 7114 grade interstitial free steel has been investigated in this study. The optimum welding parameters producing maximum joint strength were established at a peak current of 9 kA, where the electrode force is kept 6×10-5 Pa and weld time is kept constant 17 cycles, respectively. The primary cause of weakening the weldment is identified as the excessive grain growing region of heat affected zone (HAZ) in case of 7114 grade interstitial free steel.     

Treatment of originally coloured wools with garlic stem extracts and zinc chloride to ensure anti‐bacterial properties with limited colour changes

In this study, the objective was to ensure anti‐bacterial properties for originally coloured wools with naturally sourced garlic stem extracts. In addition, zinc chloride‐based treatment was also carried out. The aim was to retain the original colours of the wool fibres during these treatments. The effects of both treatments were evaluated in terms of colour changes in the wool fibres. It was found that the colour changes caused by the treatments were high in white/ecru fibres but more limited in black fibres. The colour differences between the treated and untreated black fibres were near 1; they were also quite high in white/ecru fibres. The anti‐bacterial properties of the treated wool fibres against two bacteria species, one gram‐negative and one gram‐positive, were also investigated. It was observed that zinc chloride‐based treatment ensured significant anti‐bacterial efficiencies against the bacteria tested and 99.9% bacterial reduction in all cases. However, the anti‐bacterial effects of garlic stem extract‐based treated wool fibres were limited. It was observed that treatment of wool fibres with garlic stem extracts resulted in no anti‐bacterial efficiency against Escherichia coli but did provide some anti‐bacterial capability against Staphylococcus aureus. The highest bacterial reduction of S. aureus was 80.7% in originally brown‐coloured wool fibre.     

Educational UTAUT-based virtual reality acceptance scale: a validity and reliability study

Virtual Reality - This study aims to fill a gap in current research on virtual reality (VR) by developing a valid and reliable educational VR acceptance scale based on the unified theory of...     

Development of educational virtual reality attitude scale: A validity and reliability study

Virtual Reality - The aim of the study is to address a gap in the literature by developing an educational virtual reality (edVR) attitude measurement instrument, which determines college...     

Modal analysis and improvement of lightweight wings for micro air vehicle (MAV) applications

Journal of Mechanical Science and Technology - Micro air vehicles (MAVs) are small portable flying machines designed to perform some specific tasks. Presently, the MAVs are being highly considered...     

The effect of learning analytics-based interventions in mobile learning on students' academic achievements,self-regulated learning skills,and motivations

Universal Access in the Information Society - This study examines the effects of using learning analytics (LA) in a mobile-based learning setting on students' self-regulated learning (SRL)...