Grinding arrangement for ball nose milling cutters

A grinding arrangement for spiral fluted ball nose end mills and like tools includes a tool holder for positioning the tool relative to a grinding wheel. The tool is mounted in a spindle within the tool holder for rotation about its centerline and the tool holder is pivotably mounted for angular movement about an axis which intersects that centerline. A follower arm of a cam follower secured to the spindle cooperates with a specially shaped cam to provide rotation of the tool during the angular movement of the tool holder during the grinding cycle, by an amount determined by the cam profile. In this way the surface of the cutting edge in contact with the grinding wheel is maintained at the same height on the grinding wheel throughout the angular movement of the tool holder during the grinding cycle

Bounded LTL Model Checking with Stable Models

In this paper bounded model checking of asynchronous concurrent systems is introduced as a promising application area for answer set programming. As the model of asynchronous systems a generalisation of communicating automata, 1-safe Petri nets, are used. It is shown how a 1-safe Petri net and a requirement on the behaviour of the net can be translated into a logic program such that the bounded model checking problem for the net can be solved by computing stable models of the corresponding program. The use of the stable model semantics leads to compact encodings of bounded reachability and deadlock detection tasks as well as the more general problem of bounded model checking of linear temporal logic. Correctness proofs of the devised translations are given, and some experimental results using the translation and the Smodels system are presented.Comment: 32 pages, to appear in Theory and Practice of Logic Programmin

The Myth of the Unbiased Director

This Article seeks to use social science research to better understand why these and other corporate governance problems persist. One reason may be that boards are biased as to how they respond to these issues. Social science research on risk perception informs us that individuals’ “preferences among different types of risk taking (or avoiding), correspond to cultural biases—that is, to worldviews or ideologies entailing deeply held values and beliefs defending different patterns of social relations.” Cultural theorists have identified four competing worldviews: communitarian, individualistic, hierarchical, and egalitarian. The communitarian and individualistic worldviews are at opposite ends of a spectrum measuring the degree to which an individual’s self-identity and preferred social relations derive from membership in a group...Moreover, this Article argues that directors’ decision-making may involve risk-taking with respect to matters that may carry a social charge...Further, the article presents two strategies to neutralize the impact of CIP risk assessment on corporate decision-making. One possible strategy may be that courts give greater scrutiny to directors’ decisions that particularly may be prone to risk assessment bias...Further, the Article suggests that although CIP cognition affects all directors, non-management directors may be better situated (after education) than management directors to provide a voice on the board to counteract the effects of CIP cognition...This Article does not recommend that non-management directors are the solution to the problem of CIP risk assessment on corporate boards. Also, it does not attempt to take a position about the proper role for non-management directors. This Article suggests that, indeed, under our current corporate governance system, CIP risk assessment bias may be a difficult problem to solve. There may be very few directors who are capable of exercising unbiased judgment in any directorial role

Student Engagement: An Empirical Analysis of the Effects of Implementing Mandatory Web-Based Learning Systems

Student engagement has, and will continue to be, a key desire for educators. However, some policies that are aimed at increasing engagement may actually have the opposite effect. This study of 98 students investigates one mandatory policy to use a web-based learning system and presents the level of student engagement compared to other classes where the learning system was not used. Results show that students that were required to use the web-based material had lower engagement, thus providing evidence that participation is not synonymous with engagement. Implications for practice and research are proposed

Computer Modelling Of The UK Wind Energy Resource: UK Wind Speed Data Package And User Manual

A software package has been developed for IBM-PC or true compatibles. It is designed to provide easy access to the results of a programme of work, funded by the UK Department of Energy, to estimate the UK wind energy resource. Mean wind speed maps and quantitative resource estimates were obtained using the NOABL mesoscale (1 km resolution) numerical model for the prediction of wind flow over complex terrain. NOABL was used in conjunction with digitised terrain data and wind data from surface meteorological stations for a ten year period (1975-1984) to provide digital UK maps of mean wind speed at 10m, 25m and 45m above ground level. Also included in the derivation of these maps was the use of the Engineering Science Data Unit (ESDU) method to model the effect on wind speed of the abrupt change in surface roughness that occurs at the coast. With the wind speed software package, the user is able to obtain a display of the modelled wind speed at 10m, 25m and 45m above ground level for any location in the UK. The required co-ordinates (Ordnance Survey Easting and Northing) are simply supplied by the user, and the package displays the selected wind speed. This user manual summarises the methodology used in the generation of these UK maps and shows computer generated plots of the 25m wind speeds in 200 x 200 km regions covering the whole UK. The uncertainties inherent in the derivation of these maps are also described, and notes given on their practical usage. Existing isovent maps, based on standard meteorological data which take no account of terrain effects, indicate that 10m annual mean wind speeds vary between about 4.5 and 7 m/s over the UK with only a few coastal areas over 6 m/s. The present study indicated that 23 % of the UK land area had speeds over 6 m/s, with many hill sites having 10m speeds over 10m/s. It is concluded that these 'first order' resource estimates represent a substantial improvement over the presently available 'zero order' estimates. The results will be useful for broad resource studies and initial site screening. Detailed resource evaluation for local sites will require more detailed local modelling or ideally long term field measurements

Increasing Knowledge by Leaps and Bounds: Using Experiential Learning to Address Threshold Concepts

The discussion of threshold concepts is growing in the management education literature. These concepts create challenges for students and instructors since they act as barriers to learning. The reward for overcoming these obstacles is the opening of new ways of thinking that were not available before the student mastered the threshold concepts. We propose in this article that many students believe business education is “common sense” and do not understand that management is practice informed by theory. When students master the threshold concept concerning the “underlying game” of management, they begin to develop deeper and more meaningful understandings. From this perspective we demonstrate how we have used experiential exercises in an operations management class to facilitate active, social, and creative learning that exposes this threshold concept and moves the student through the preliminal, liminal, and postliminal stages of threshold concept mastery

Administrative Withdrawal Policies: ‘Good’ Policies or ‘Bad’ Ethics

Many universities have adopted Administrative Withdrawal Policies that allow administrators to remove students from classes without the student’s permission. These policies potentially protect students but also provide a means of artificially improving key funding metrics. This study uses Agency Theory to examine over 1,100 Division I, II, and III U.S. universities and compares the usage of Administrative Withdrawal Policies to state and federal funding. Results show Division II schools receiving less state funding have adopted these policies at a higher rate than Division II schools receiving more. Recommendations for future use of these policies is provided