A feeder-calf price model is estimated which incorporates elements of break-even budget analysis, including estimates of placement weights, slaughter weights, ration cost, and feed-conversion rates. From this model, a corn price multiplier is calculated which quantifies the corn/feeder-calf price relationship. Because the multiplier includes information on cattle weight, feed conversion, and ration cost, it also provides insight into how feeding programs are altered in response to corn price changes. Changes in feeding programs which occur in response to corn price changes are illustrated with dynamic simulation based on weight, ration cost, and price models presented here.

This paper presents a new biped mechanism with low-cost easy-operation features. The mechanism is designed with functions for straight walking, changing direction, overcoming obstacle, and climbing stairs with only 7 DOFs (degrees of freedom). Dynamics of the biped mechanism are analyzed by means of simulations in the MSC.ADAMS environment. Simulation results in terms of motion torque, joint force, contact force, parts displacement, velocity, and acceleration are reported and analyzed to show the feasibility and efficiency of the proposed solution. In addition, with the simulation results, dynamical motion of the biped mechanism is investigated and its operation performances are characterized as well.

Dynamic simulation in robotic systems can be considered as a useful tool not only for the design of both mechanical and control systems, but also for planning the tasks of robotic systems. Usually, the dynamic model suffers from discontinuities in some parts of it, such as the use of Coulomb friction model and the contact problem. These discontinuities could lead to stiff differential equations in the simulation process. In this paper, we present an algorithm that solves the discontinuity problem of the Coulomb friction model without applying any normalization. It consists of the application of an external switch that divides the integration interval into subintervals, the calculation of the friction force in the stick phase, and further improvements that enhance its stability. This algorithm can be implemented directly in the available commercial integration routines with event-detecting capability. Results are shown by a simulation process of a simple 1-DoF oscillator and a 3-DoF parallel robot prototype considering Coulomb friction in its joints. Both simulations show that the stiffness problem has been solved. This algorithm is presented in the form of a flowchart that can be extended to solve other types of discontinuity.

In this paper the mechanical design for a new 7-dofs leg is investigated as a walking module for a humanoid robot. In particular, a dynamic simulation is deduced by means of a Newton-Euler formulation and implemented numerically in order to compute the needed input actuator torques. A simulation is carried out for a similar built leg prototype that is used as a walking module for WABIAN-RIV (WAseda BIped humANoid robot-Revised IV). Experimental tests are carried out on this existing leg in order to validate the proposed formulation for a similar application. Thus, the validated formulation has been used in order to design the actuators for a new leg prototype.

The exponential growth of the Internet and increasing communication and computational power have created many opportunities for advancing engineering, manufacturing, and business activities. Among them are electronic catalogs. These have become basic information resources to a number of people, ranging from shoppers looking for personal items to engineers selecting electromechanical parts to build a product. Although rich in content, current catalog systems are limited both in search quality and in realizing the full potential of the retrieved information. The active catalog system brings a conceptually new idea to electronic commerce by providing a new, computationally usable, catalog information environment about components and their use in applications. It utilizes a rich body of domain knowledge to facilitate access and retrieval of component information. The utility of retrieved information is enhanced by using it to rapidly construct simulation programs and test alternatives, supporting a “try before you buy” paradigm in which users evaluate candidate components within simulations of their design. We describe services provided in the active catalog system to support engineers in selecting and evaluating electromechanical components and subsystems. The services include mechanisms for creating queries for parts based on their intended use rather than merely parametric specifications, refining those queries to take account of constraints imposed by domain knowledge, providing multimodal information to help engineers assess and compare candidate parts, and generating simulation models for candidate parts and integrating them to provide simulation models for candidate systems.