Behavioral modeling of DRACO : a peripheral interface ASIC

This paper describes the behavioral modeling of DRACO, a peripheral interface Application Specific Integrated Circuit (ASIC) developed by Rockwell International for numerical control applications. The behavioral model was generated from a data sheet of the fabricated chip, which primarily described the chip's input-output functionality, physical and operational characteristics, and a functional block diagram. The data sheet contained very little abstract behavioral information. This report describes the abstract behavioral model of the DRACO chip, and uses flowcharts and VHDL to capture the behavior. The behavioral model was developed through reverse engineering of the data sheet description, supplemented by further consultation with designers of the DRACO ASIC at Rockwell Intemational. The report describes typical behavioral test sequences that were applied to the DRACO VHDL model to verify its correctness. The appendices contain the original DRACO datasheet and the VHDL code used to capture DRACO's behavior

Performance Implications of Diversification in Professional Service Firms: The Role of Synergies

There is growing interest in the Professional service firms because they are seen as archetype of the knowledge-based economy. In this study we look at under researched area of exploitation of synergies in professional service firms and its implications for performance. Overcoming the uni-dimensional nature of extant studies, we examine the performance implications of diversification along the twin dimensions of services they offer and the knowledge of the industry domain of their clients. We hypothesize that moderate levels of coherence in these dimensions lead to improved performance while excess coherence in these domains lead to diminished performance. These predictions are tested and supported by data from the Indian IT industry which is synonymous with emergence of knowledge economy in India. Our study thus contributes to the theory of diversification of professional service firms.

Trace Elements in Soils of the South Texas Uranium District: Concentrations, Origin, and Environmental Significance

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On Optimal Mechanisms in the Two-Item Single-Buyer Unit-Demand Setting

We consider the problem of designing a revenue-optimal mechanism in the two-item, single-buyer, unit-demand setting when the buyer's valuations, $(z_1, z_2)$, are uniformly distributed in an arbitrary rectangle $[c,c+b_1]\times[c,c+b_2]$ in the positive quadrant. We provide a complete and explicit solution for arbitrary nonnegative values of $(c,b_1,b_2)$. We identify five simple structures, each with at most five (possibly stochastic) menu items, and prove that the optimal mechanism has one of the five structures. We also characterize the optimal mechanism as a function of $b_1, b_2$, and $c$. When $c$ is low, the optimal mechanism is a posted price mechanism with an exclusion region; when $c$ is high, it is a posted price mechanism without an exclusion region. Our results are the first to show the existence of optimal mechanisms with no exclusion region, to the best of our knowledge

Almost Budget Balanced Mechanisms with Scalar Bids For Allocation of a Divisible Good

This paper is about allocation of an infinitely divisible good to several rational and strategic agents. The allocation is done by a social planner who has limited information because the agents' valuation functions are taken to be private information known only to the respective agents. We allow only a scalar signal, called a bid, from each agent to the social planner. Yang and Hajek [Jour. on Selected Areas in Comm., 2007] as well as Johari and Tsitsiklis [Jour. of Oper. Res., 2009] proposed a scalar strategy Vickrey-Clarke-Groves (SSVCG) mechanism with efficient Nash equilibria. We consider a setting where the social planner desires minimal budget surplus. Example situations include fair sharing of Internet resources and auctioning of certain public goods where revenue maximization is not a consideration. Under the SSVCG framework, we propose a mechanism that is efficient and comes close to budget balance by returning much of the payments back to the agents in the form of rebates. We identify a design criterion for {\em almost budget balance}, impose feasibility and voluntary participation constraints, simplify the constraints, and arrive at a convex optimization problem to identify the parameters of the rebate functions. The convex optimization problem has a linear objective function and a continuum of linear constraints. We propose a solution method that involves a finite number of constraints, and identify the number of samples sufficient for a good approximation.Comment: Accepted for publication in the European Journal of Operational Research (EJOR