Influence of Confining Pressure on the Crack Growth Behavior in a Highly Filled Elastomer

In this study, the effect of confining pressure on the crack growth behavior in a highly filled elastomer was investigated. The material under investigation contains 86% by weight of hard particles embedded in a rubbery matrix. The specimens were tested at a constant strain rate under a confining pressure. Two confining pressures, 3.45 MPa and 6.9 MPa, and two types of loading, monotonically increasing and cyclic, were considered. The experimental data were analyzed, and the effects of confining pressure on the damage process as well as the constitutive and crack growth behavior in the material are discussed

PID Controller Tuning Optimization with BFO Algorithm in AVR System

This study presents the design and tuning of Proportional Integral Controller (PID) for Automatic Voltage Regulator (AVR) system to improve the dynamic performance and robustness of the system. The PID controller is the very commonly used compensating controller which is used in higher order system. This controller widely used in many different areas like Chemical process control, Aerospace, Automation and Electrical Drives etc. There are various soft computing techniques which are used for tuning of PID controller to control the voltage in AVR system. Tuning of PID parameters is important because, these parameters have a great effect on the stability and performance of the control system. Bacterial Foraging Optimization (BFO) techniques is one of the important techniques to tune the PID parameter in AVR system. Numerical solution based on the proposed PID control of an AVR system for nominal system parameters and step reference voltage input validates the good performance

UNDERSTANDING COUNTRY CLUB MEMBERS’ LOYALTY: FACTORS AFFECTING MEMBERSHIP RENEWAL DECISIONS

Many private country clubs across the United States have experienced a declining or flat membership and smaller waitlists of members wanting to join. The objective of this study was to investigate whether member involvement, service quality, and perceived value, influence member satisfaction and intention to renew membership for members of private country clubs. An online survey instrument customized for the country club industry was distributed to members of two country clubs in northeast Ohio. Results indicate that involvement level of members and perceived value impact country club members’ satisfaction and intention to renew their membership. Managerial implications are discussed

Artificial Intelligence and Machine Learning: A Perspective on Integrated Systems Opportunities and Challenges for Multi-Domain Operations

This paper provides a perspective on historical background, innovation and applications of Artificial Intelligence (AI) and Machine Learning (ML), data successes and systems challenges, national security interests, and mission opportunities for system problems. AI and ML today are used interchangeably, or together as AI/ML, and are ubiquitous among many industries and applications. The recent explosion, based on a confluence of new ML algorithms, large data sets, and fast and cheap computing, has demonstrated impressive results in classification and regression and used for prediction, and decision-making. Yet, AI/ML today lacks a precise definition, and as a technical discipline, it has grown beyond its origins in computer science. Even though there are impressive feats, primarily of ML, there still is much work needed in order to see the systems benefits of AI, such as perception, reasoning, planning, acting, learning, communicating, and abstraction. Recent national security interests in AI/ML have focused on problems including multidomain operations (MDO), and this has renewed the focus on a systems view of AI/ML. This paper will address the solutions for systems from an AI/ML perspective and that these solutions will draw from methods in AI and ML, as well as computational methods in control, estimation, communication, and information theory, as in the early days of cybernetics. Along with the focus on developing technology, this paper will also address the challenges of integrating these AI/ML systems for warfare

Experimental investigation of the shearing resistance of SODA-Lime glass at pressures of 9 GPa and strain rates of 10^6 s^(-1)

Pressure-Shear Plate Impact (PSPI) experiments were conducted to measure the high-rate shearing resistance of soda-lime glass at pressures of 9 GPa and at shearing rates of approximately 10^6 s^(−1). Samples of soda lime glass, 5 µm thick, were sandwiched between pure tungsten carbide (WC) plates and impacted by pure WC flyers. Impacting plates were inclined to the direction of approach by an angle of 18°. Normal stress and shearing resistance of the sample were calculated from measured free surface velocities using 1D elastic wave theory. The experimental results show that, at a pressure of 9GPa, the shear stress increases almost linearly up to 1 GPa and then falls quickly to approximately 0.3 GPa — after which it decreases slowly to approximately 0.17 GPa. Comparisons with results of previous experiments on nominally identical samples, impacted to generate lower peak pressures, showed the peak shearing resistance to be much higher at higher pressures; however, the sharp fall in shearing resistance occurs at comparable shear strains (1.5-2)