Adaptive Feed Rate Policies for Spiral Drilling Using Markov Decision Process

In this study, the feed rate optimization model based on a Markov Decision Process (MDP) was introduced for spiral drilling process. Firstly, the experimental data on spiral drilling was taken from literature for different axial force parameters and with various feed rate decisions made, having the length of a hole being drilled as a reward. Proposed optimization model was computed using value iteration method. Secondly, the results of computations were displayed for optimal decision to be made on each state. Proposed decisions for an optimal feed rate could be utilized in order to improve the efficiency of spiral drilling process in terms of cost and time

Graphic Processing Units (GPUs)-Based Haptic Simulator for Dental Implant Surgery

This paper presents a haptics-based training simulator for dental implant surgery. Most of the previously developed dental simulators are targeted for exploring and drilling purpose only. The penalty-based contact force models with spherical-shaped dental tools are often adopted for simplicity and computational efficiency. In contrast, our simulator is equipped with a more precise force model adapted from the Voxmap-PointShell (VPS) method to capture the essential features of the drilling procedure, with no limitations on drill shape. In addition, a real-time torque model is proposed to simulate the torque resistance in the implant insertion procedure, based on patient-specific tissue properties and implant geometry. To achieve better anatomical accuracy, our oral model is reconstructed from cone beam computed tomography (CBCT) images with a voxel-based method. To enhance the real-time response, the parallel computing power of GPUs is exploited through extra efforts in data structure design, algorithms parallelization, and graphic memory utilization. Results show that the developed system can produce appropriate force feedback at different tissue layers during pilot drilling and can create proper resistance torque responses during implant insertion

Characterization and geometric modeling of single and overlapping craters in micro-EDM

10.1080/10910344.2015.1085317Machining Science and Technology20179-9

Marketing of consumer loans

In Singapore today, everything from shampoo to designer wears come in an array of brands and packagings. Financial products are no exception.BUSINES

An empirical study on the characterization of machined surface integrity by chip morphology in dry end-milling of titanium alloy

Titanium alloys manifest low thermal conductivity and high work hardenability in machining. These alloys are thus considered as difficult-to-machine at higher cutting speeds and pose serious problems in machining such as degraded machined surface and rapid tool-wear. Mostly, the integrity of the machined surface is assessed by post-process microscopic examination or by metallurgical testing techniques where machined workpiece needs to be further processed to perform subsequent testing on sophisticated equipment in usually meticulous ways. This study presents a qualitative but simple approach for the rapid characterization of the machined surface integrity in high-speed milling of titanium alloy. It has been established empirically that the chip morphology carries significant information about the machined surface integrity, and hence, can be considered as a reliable representative of the machined surface integrity