Electrical Discharge Machining performance is generally evaluated on the basis of Material Removal Rate (MRR), Tool Wear Rate (TWR), Relative Wear Ratio (RWR) and Surface Roughness (SR). The important EDM machining parameters affecting to the performance measures of the process are discharge current, pulse on time, pulse off time, arc gap, and duty cycle [9]. A considerable amount of work has b...

By leveraging the capabilities of modern GPS-equipped mobile devices providing social-networking services, the interest in developing advanced services that combine location-based services with social networking services is growing drastically. Based on geo-social networks that couple personal location information with personal social context information, such services are facilitated by geo-so...

We present two simple algorithms for SAT and prove upper bounds on their running time. Given a Boolean formula F in conjunctive normal form, the first algorithm finds a satisfying assignment for F (if any) by repeating the following: Choose an assignment A at random and search for a satisfying assignment inside a Hamming ball around A (the radius of the ball depends on F ). We show that this al...

in this research, the efficiency of the comminution circuit as well as the efficiency of size classification equipment of the concentrator plant 2 of sarcheshmeh copper complex was studied. the comminution circuit of this plant includes one sag mill in a closed circuit with a vibrating screen and one ball mill with a size classification system of hydrocyclone. the goal of this work was to calcu...

We discuss geometric special cases of optimization problems on graphs where the n vertices are represented as points in IR d and where the lengths of the edges are measured according to a norm with a polyhedral unit ball. We derive algorithms whose running time is polynomial in n (and depends exponentially on the number of faces of the unit ball). We consider the maximum travelling salesman pro...

In a prospective study of 302 adolescent players in three ball games (soccer, handball and basketball), 119 incurred injuries. The injury incidence (number of injuries per 1000 playing hours) was 5.6 in soccer, 4.1 in handball and 3.0 in basketball. Ankle sprains accounted for 25 per cent of the injuries, finger sprains 32 per cent, strains in the thigh and leg 10 per cent, and tendinitis/apoph...

Visually guided action implies the existence of information as well as a control law relating that information to movement. For ball catching, the Chapman Strategy--keeping constant the rate of change of the tangent of the elevation angle (d(tan(alpha))/dt)--leads a catcher to the right location at the right time to intercept a fly ball. Previous studies showed the ability to detect the informa...

Although changes of direction are one of the essential locomotor patterns in ball sports, the physiological demand of turning during running has not been previously investigated. We proposed a novel approach by which to evaluate the physiological demand of turning. The purposes of this study were to establish a method of measuring the energy expenditure (EE) of a 180° turn during running and to...

P. McLeod, N. Reed, and Z. Dienes (2002) argued that the linear optical trajectory (LOT) strategy incorrectly cues fielders to run forward for balls headed beyond them. The authors of this article explain that the downward optical curvature found for balls landing beyond the fielder's initial position occurs because the balls reorient the direction the fielder is facing during pursuit. Thus, wh...