Black Power At Work: Community Control, Affirmative Action, and the Construction Industry

{Excerpt} As the contributors to this book show, confrontations with the building trades unions became a critical axis for the rise of Black Power and community control politics, and provide a means for us to rethink the history of Black Power through the fusion by the movement of community control and labor organizing. By tracing the evolution of these activists\u27 organizing methods and analysis, we show that African American grassroots struggles to desegregate the construction industry provided a major, and in some cities the, means through which Black Power movements became ascendant in African American urban politics. Only through close attention to local politics are these profound cultural and political shifts visible. Because of their decentralized quality, the movements for community control of the construction industry varied by city, based on the idiosyncratic nature of the specific African American communities and political networks from which they emerged. These differences were accentuated by weak federal enforcement of affirmative action plans, which relied on a strategy of localism that placed the origin, evolution, and fate of construction industry affirmative action plans primarily in the hands of local actors and courts

The Missing Basics & Other Philosophical Reflections for the Transformation of Engineering Education

The paper starts by reflecting on what senior engineering students don't know how to do when they confront a real-world project in an industrially sponsored senior design project. Seven, largely qualitatively, skills are found to be lacking: questioning, labeling, qualitatively modeling, decomposing, measuring, ideating, and communicating. These skills, some of the most important critical and creative thinking skills in the arsenal of modern civilization, are termed "the missing basics" and contrasted with what engineering faculty usually call "the basics." The paper critically examines the term "the basics" and other terms that are conceptual hurdles to fundamental reassessment of engineering education at this time. The paper concludes that the engineering academy is stuck in a Kuhnian paradigm born in the cold war, that the reflexive belief in the superiority of math, science, and engineering science to the exclusion of other topics is not itself scientific, and that the use of tired code words is not an argument or a rational defense of a paradigm that may have outlived its usefulness. The paper concludes by highlighting the role philosophy can play in clearing away the conceptual confusion, thereby permitting a more reasoned conversation on the needs of engineering education in our times

On the rate of convergence to stationarity of the M/M/N queue in the Halfin-Whitt regime

We prove several results about the rate of convergence to stationarity, that is, the spectral gap, for the M/M/n queue in the Halfin-Whitt regime. We identify the limiting rate of convergence to steady-state, and discover an asymptotic phase transition that occurs w.r.t. this rate. In particular, we demonstrate the existence of a constant $B^*\approx1.85772$ s.t. when a certain excess parameter $B\in(0,B^*]$, the error in the steady-state approximation converges exponentially fast to zero at rate $\frac{B^2}{4}$. For $B>B^*$, the error in the steady-state approximation converges exponentially fast to zero at a different rate, which is the solution to an explicit equation given in terms of special functions. This result may be interpreted as an asymptotic version of a phase transition proven to occur for any fixed n by van Doorn [Stochastic Monotonicity and Queueing Applications of Birth-death Processes (1981) Springer]. We also prove explicit bounds on the distance to stationarity for the M/M/n queue in the Halfin-Whitt regime, when $B<B^*$. Our bounds scale independently of $n$ in the Halfin-Whitt regime, and do not follow from the weak-convergence theory.Comment: Published in at http://dx.doi.org/10.1214/12-AAP889 the Annals of Applied Probability (http://www.imstat.org/aap/) by the Institute of Mathematical Statistics (http://www.imstat.org

Correlation Decay in Random Decision Networks

We consider a decision network on an undirected graph in which each node corresponds to a decision variable, and each node and edge of the graph is associated with a reward function whose value depends only on the variables of the corresponding nodes. The goal is to construct a decision vector which maximizes the total reward. This decision problem encompasses a variety of models, including maximum-likelihood inference in graphical models (Markov Random Fields), combinatorial optimization on graphs, economic team theory and statistical physics. The network is endowed with a probabilistic structure in which costs are sampled from a distribution. Our aim is to identify sufficient conditions to guarantee average-case polynomiality of the underlying optimization problem. We construct a new decentralized algorithm called Cavity Expansion and establish its theoretical performance for a variety of models. Specifically, for certain classes of models we prove that our algorithm is able to find near optimal solutions with high probability in a decentralized way. The success of the algorithm is based on the network exhibiting a correlation decay (long-range independence) property. Our results have the following surprising implications in the area of average case complexity of algorithms. Finding the largest independent (stable) set of a graph is a well known NP-hard optimization problem for which no polynomial time approximation scheme is possible even for graphs with largest connectivity equal to three, unless P=NP. We show that the closely related maximum weighted independent set problem for the same class of graphs admits a PTAS when the weights are i.i.d. with the exponential distribution. Namely, randomization of the reward function turns an NP-hard problem into a tractable one