An optimal resolved rate law for kinematically redundant manipulators

The resolved rate law for a manipulator provides the instantaneous joint rates required to satisfy a given instantaneous hand motion. When the joint space has more degrees of freedom than the task space, the manipulator is kinematically redundant and the kinematic rate equations are underdetermined. These equations can be locally optimized, but the resulting pseudo-inverse solution has been found to cause large joint rates in some cases. A weighting matrix in the locally optimized (pseudo-inverse) solution is dynamically adjusted to control the joint motion as desired. Joint reach limit avoidance is demonstrated in a kinematically redundant planar arm model. The treatment is applicable to redundant manipulators with any number of revolute joints and to non-planar manipulators

An optimal resolved rate law for kindematically redundant manipulators

The resolved rate law for a manipulator provides the instantaneous joint rates required to satisfy a given instantaneous hand motion. When the joint space has more degrees of freedom than the task space, the manipulator is kinematically redundant and the kinematic rate equations are underdetermined. These equations can be locally optimized, but the resulting pseudo-inverse solution was found to cause large joint rates in some case. A weighting matrix in the locally optimized (pseudo-inverse) solution is dynamically adjusted to control the joint motion as desired. Joint reach limit avoidance is demonstrated in a kinematically redundant planar arm model. The treatment is applicable to redundant manipulators with any number of revolute joints and to nonplanar manipulators

Jurisdictional Issues: The EEC Merger Control Regulation, Member State Laws, and Articles 85 and 86

This Article deals with two main issues. One is the division of powers between the European Economic Community and the Member States with regard to merger control after September 21, 1990. The other is the possible application, by the Commission of the European Communities or by national authorities, of Article 85 and 86 of the Treaty Establishing the European Economic Community to mergers covered by Regulation No. 4064/89. The Article casts a brief look at how the dividing line between merges and operations which do not qualify as mergers within the sense of article 3 of the Regulation will be treated in the future

Product differentiation under the WTO; An analysis of labelling and tariff or tax measures concerning farm animal welfare

This report examines the possibility of giving preferential treatment to imports of meat products that meet improved standards in terms of animal welfare in production. Three specific forms of preferential treatment are considered here as possible measures for increasing levels of animal welfare in meat production in the EU and its exporting partners: labelling of products (either voluntary or compulsory), differentiated import tariffs and differentiated consumer taxes. The likely admissibility of such measures under WTO rules is assessed by means of an analysis of previous decisions by WTO dispute settlement panels. It is concluded that all of the measures analysed have a possibility of being upheld, based on a defence relying on Article XX of the GATT and perhaps also the TBT Agreement. While the incentives offered by labelling could be reinforced with differentiated tariffs or taxes, these financial instruments involve various additional complications. They could best be considered after the possibilities of regulated labelling schemes have been exhausted.International Relations/Trade,

Praise in the Elementary Classroom: The Teacher’s Perspective

While words of encouragement from teachers may seem innocuous on the surface, the practice may have hidden costs (Kohn, 1993). Although effective in the short-run, the use of extrinsic motivators, such as praise, has been shown to have an undermining effect on long-term motivation to learn (Deci & Ryan, 2000). Mindful of the fact that academic intrinsic motivation decreases from ages 9-18 (Gottfried & Gottfried, 1996, 2006), the present study sought to gain insight into the phenomenon of classroom praise from the perspective of 105 elementary teachers, revealing their explanation and justification for this practice. Although research has documented the effects of praise in the school setting (Deci & Ryan, 2000; Kohn, 1993; Reeve, 2006), there have been few accounts of how and why teachers administer praise. The realities of the elementary classroom, including student discipline, standardized curriculum, and high-stakes testing, provide context for understanding the implementation of systems of incentives. While the open-ended descriptions of motivational techniques are insightful in their own right, the teachers’ explanations and justification for these approaches represent a philosophy of education, one that both reflects and shapes our culture

Contingent Rewards in the Elementary Classroom: The Teacher’s Perspective

With growing force, extrinsic motivators, such as stickers, certificates, gold stars, and monetary compensation, permeate the educational environment (Kohn, 1993). While innocuous on the surface, such incentive-laden practices represent a level of teacher control that has profound consequences for student motivation (Reeve, 2006). Although considerable field experiments have shown the effects of contingent rewards on subsequent intrinsic motivation for engaging in proscribed activities (Deci & Ryan, 1985), such studies do not shed light on the motivational realities of the classroom environment, complete with student discipline, standardized curricula, and accountability measures. One hundred five (105) elementary teachers of grades one to five within a single school district in the Southern United States responded to Likert-type items and open-ended questions, allowing them to articulate and justify their use of systems of rewards and sanctions in the classroom. Results indicated that the overwhelming majority of teachers (95%) had systems of rewards and consequences/sanctions, which they deemed effective and pedagogically appropriate. Teachers revealed highly developed token economies spanning both the students’ behavioral and academic outcomes. While this study is descriptive and exploratory in nature, it attempts to provide context for further research in an area of pressing concern that needs to be reclaimed