One of the major factors hindering the use of qualitative simulation techniques to reason about the behavior of complex dynamical systems is intractable branching due to a phenomenon called chatter. Chatter occurs when a variable's direction of change is constrained only by continuity within a region of the state space . This results in intractable, potentially infinite branching within the beh...

This paper presents the suitable depth of cut, spindle speed and feed rate that will be chosen during machining. If thus parameters are not considered, this can provoke abnormal tool behavior such as chatter. Chatter will limit the tool life which only can be use for just a few times. To predict the chatter occurs, the parameters will be use are spindle speed, depth of cut and feed rate. CNC ma...

T study examines whether user-generated content (UGC) is related to stock market performance, which metric of UGC has the strongest relationship, and what the dynamics of the relationship are. We aggregate UGC from multiple websites over a four-year period across 6 markets and 15 firms. We derive multiple metrics of UGC and use multivariate time-series models to assess the relationship between ...

We conducted a tutoring experiment to determine whether female brown-headed cowbirds (Molothrus ater) would attend to vocalizations of other females and use those cues to influence their own preferences for male courtship songs. We collected recordings of male songs that were unfamiliar to the subject females and paired half of the songs with female chatter vocalizations-vocalizations that fema...

Chatter is a complicated problem faced by machine tool operators. Chatter is a self-excited vibration that can occur during machining operations. This is an undesirable phenomenon which limits the productivity of the machine. A lot of techniques have been developed to control the chatter. Stability lobe diagram is an effective tool which helps the operator to select specific spindle speeds duri...

Unstable cutting due to chatter vibrations is one of the most important problems during metal cutting operations. Chatter can be a limitation for productivity and surface quality in turning operations, especially when long and slender tools and parts are involved. In this study, an analytical stability method for turning process is presented. The model takes the cutting geometry into considerat...

Chatter stability in milling can be improved significantly using variable pitch cutters. The pitch angles can be optimized for certain chatter frequency and spindle speed ranges using the analytical method presented in the first part of this two-part paper. In this part, the improvement of productivity and surface finish are demonstrated in three example applications. It is shown that chatter s...

Chatter is an instability phenomenon in machining processes which limits productivity and results in inferior workpiece quality, noise and rapid tool wear. The increasing demand for productivity in the manufacturing community motivates the development of an active control strategy to shape the chatter stability boundary of manufacturing processes. In this work a control methodology for the high...

& Stability boundaries for milling are predicted by the zeroth-order approximation (ZOA) and the semi-discretization (SD) methods. For high radial immersions, the methods predict similar stability boundaries. As radial immersion is decreased, the disagreement between the predictions of the two methods grows considerably. The most prominent difference is an additional type of instability predict...

Chatter has been recognized as major restriction for the increase in productivity of cold rolling processes, limiting the rolling speed for thin steel strips. It is shown that chatter has close relation with rolling conditions. So the main aim of this paper is to attain the optimum set points of rolling to achieve maximum rolling speed, preventing chatter to occur. Two combination methods were ...