Judicial Incoherence, Capital Punishment, and the Legalization of Torture

This brief essay responds to the Supreme Court’s recent decision in Bucklew v. Precythe. It contends that the argument relied upon by the Court in that decision, as well as in Glossip v. Gross, is either trivial or demonstrably invalid. Hence, this essay provides a nonmoral reason to oppose the Court’s recent capital punishment decisions. The Court’s position that petitioners seeking to challenge a method of execution must identify a readily available and feasible alternative execution protocol is untenable, and must be revisited

Modeling the kinematics and Dynamics of Compliant Contact

In this paper, we discuss the modeling of the kinematics and dynamics of compliant contact between bodies moving in Euclidean space. First, we derive the kinematic equations describing the motion of the contact point when two rigid bodies are rolling on each other. Secondly, we extend these results to describe the motion of the closest points between two rigid bodies moving freely in space. Then, we use these results to model compliant contact between bodies, using a spatial spring and a damper to model energy stored and dissipated during contact

Modeling Framework and Software Tools for Walking Robots

In research on passive dynamic walking, the aim is to study and design robots that walk naturally, i.e., with little or no control effort. McGeer [1] and others (e.g. [2, 3]) have shown that, indeed, robots can walk down a shallow slope with no actuation, only powered by gravity.\ud In this work, we derive mathematical models of walking ro- bots to better understand the dynamics that determine the walking behavior, and to design controllers that e.g. in- crease robustness against changing environments. We use the port-Hamiltonian framework, as it has the advantage of explicitly showing energy-flows inside and into the system. Thus, it allows a direct efficiency study as well as the possi- bility to connect external elements in a ‘physical’ way using ports, instead of using just torque/force signals

Passive compensation of nonlinear robot dynamics

In this paper, we derive a coordinate-free formulation of a passive controller that makes a mechanical system track reference curves in a potential field. Contrary to conventional reference tracking, we do not specify a single time-varying trajectory that the system has to track. Instead, we specify a whole curve that the system has to stay on at all times. Using tools from differential geometry, we first derive a controller that makes the system move along arbitrary (smooth enough) reference curves while keeping the kinetic energy constant. We then apply the results to the case of movement in an artificial potential field, in which case, the reference curves are completely determined by the potential field and cannot be chosen arbitrarily. Simulation then shows the performance of the controller on a benchmark robot with two degrees of freedom

Dynastic Centres in Europe and Asia : A Layout for Comparison

In this paper, I seek to prepare the way for a comparative analysis of dynastic centres in Europe and Asia. This is a timely challenge, following trends in European historiography stressing the persistence of household structures and ritual at the heart of the early modern state, as well as recent detailed studies of Asian courts. Clearly patterns varied greatly, but the divergences should not be fitted unthinkingly into a grand narrative based on the ‘rise of the west’. Among the issues equally relevant for courts in Europe and Asia, I privilege two. In the first place, all rulers needed loyal agents, yet could not easily guarantee their loyalty over time. Agents in the long run tend to become vested interest groups, standing in the way of the ruler’s personal power. The court was a main theatre where this tension could be solved or exacerbated. In the second place the dynastic centre with its redistributive function and its calendar of rituals could offer a point of orientation for regional elites not otherwise connected, hence bringing cohesion to loosely governed multi-ethnic empires or composite monarchies. After considering comparative strategies and problems related to scope, as well as obstacles created by languages and sources, I elaborate in some detail four foci for research: 1) the ruler himself (or more rarely herself); 2) the dynasty, succession, reproduction (evidently including women as well as siblings); 3) the status, composition, and tasks of the groups serving the ruler; and finally 4) the connections of this grouping with its wider social environment. It is my contention that in each of these four subsequent concentric circles we can define a series of questions relevant for all dynastic centres, notwith¬standing huge cultural differences separating civilizations, regions, and periods. Using diachronic and synchronic approaches to study a focused theme, I hope to reach a level of comparative precision that goes beyond open generalized statements while retaining analytical precision and proximity to sources. This can only be structured as a joint effort, the outlines of which are suggested here

Port based modeling of spatial visco-elastic contacts

In this paper, the geometrical description of viscoelastic contacts is described using physical modeling concepts based on energy conservation and network theory. The proposed model is on one side simple enough to be used in real time applications and on the other captures the geometrical features and coupling of a complete spatial geometric unisotropical contact