We demonstrate 4-channel, 2GHz weighted addition in a silicon microring filter bank. Accurate analog weight control becomes more difficult with increasing number of channels, N, as feedback approaches become impractical and brute force feedforward approaches take O(2N) calibration measurements in the presence of inter-channel dependence. We introduce model-based calibration techniques for therm...

NURPS surfaces are the rational extension of Powell-Sabin splines in their normalized B-spline representation. In this paper we study the influence of modifying the weights of a NURPS surface. We describe the relation between the weights associated with a control triangle and the points on the NURPS surface by means of a double volume ratio. We also extend the concept of Farin points for ration...

In practice, almost all control systems in use today implement some form of linear control. However, there are many tasks for which conventional control engineering methods are not directly applicable because there is not enough information about how the system should be controlled (i.e. reinforcement learning problems). In this paper, we explore an approach to such problems that evolves fast-w...

The prevalence of obesity is increasing which becomes worrisome due to its association with several diseases and certain types of cancers. While weight control through dietary caloric restriction and/or physical activity protects against cancer in animal models, the underlying mechanisms are not fully defined. Weight loss due to negative energy balance is associated with alterations of multiple...

H∞ control design is generally performed iteratively. At each iteration, the weights constraining the desired closed-loop transfer functions are adjusted until satisfactory performance margins are obtained. The way in which the weights are adjusted is generally heuristic and based solely on past experience and engineering judgement/intuition. It is consequently important to understand and provi...

Bariatric surgery Carroll M. Harmon, Birmingham, Alabama, reviewed the topic of bariatric surgery in children. A typical response to the topic, he said, is of disbelief that such an approach would even be considered. Yet more than one million adolescents and young adults have BMI 40 kg/m, and obesity is by far the most common nutritional disorder among children in the U.S. Childhood obesity is ...