Who Edits the Editors? Snake Hill and Archaeological Reports

A review of Snake Hill: An Investigation of a Military Cemetery from the War of 1812, edited by Susan Pfeiffer and Ronald F. Williamson, provides a coign of vantage regarding two aspects of particular concern to historical archaeologists. One is the increasing number of historical cemeteries that, because of recent legislation and a broadening of research domains, are being investiagted by archaeologists. The other, closely related, aspect is the need for strong editorial oversight in preparing for the press reports that comprise the contributions of diverse specialists. Snake Hill was a good project that resulted in a report that, while useful, bears deficiencies that underscore the necessity for thoughtful compilation of edited volumes

A Look at the Generalized Heron Problem through the Lens of Majorization-Minimization

In a recent issue of this journal, Mordukhovich et al.\ pose and solve an interesting non-differentiable generalization of the Heron problem in the framework of modern convex analysis. In the generalized Heron problem one is given $k+1$ closed convex sets in \Real^d equipped with its Euclidean norm and asked to find the point in the last set such that the sum of the distances to the first $k$ sets is minimal. In later work the authors generalize the Heron problem even further, relax its convexity assumptions, study its theoretical properties, and pursue subgradient algorithms for solving the convex case. Here, we revisit the original problem solely from the numerical perspective. By exploiting the majorization-minimization (MM) principle of computational statistics and rudimentary techniques from differential calculus, we are able to construct a very fast algorithm for solving the Euclidean version of the generalized Heron problem.Comment: 21 pages, 3 figure

Tooling adjustment strategy for acceptable product quality in assembly processes

This paper develops an approach to minimize the number of process tooling adjustments and deliver an acceptable fraction of non-conforming products based on given product quality specification limits in assembly processes. A linear model is developed to describe the relationships between product quality and process tooling locating positions. Based on the model, the process mean shifts of tooling locating positions are estimated for both deterministic and stochastic cases by using the least-square estimation or linear mixed model estimation, respectively. A simultaneous confidence interval is obtained to construct the estimation region of a process mean shift under the given false alarm rate. Furthermore, a tooling adjustment strategy is proposed to determine when the process adjustment is essentially needed in order to ensure an acceptable fraction of non-conforming units based on the given product quality specification limits. Finally, a case study is conducted to illustrate the developed methodology by using a real-world autobody assembly process. Copyright © 2010 John Wiley & Sons, Ltd.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/78245/1/1128_ftp.pd

Exact algorithms for integrated facility location and production planning problems

We consider a class of facility location problems with a time dimension, which requires assigning every customer to a supply facility in each of a finite number of periods. Each facility must meet all assigned customer demand in every period at a minimum cost via its production and inventory decisions. We provide exact branch‐and‐price algorithms for this class of problems and several important variants. The corresponding pricing problem takes the form of an interesting class of production planning and order selection problems. This problem class requires selecting a set of orders that maximizes profit, defined as the revenue from selected orders minus production‐planning‐related costs incurred in fulfilling the selected orders. We provide polynomial‐time dynamic programming algorithms for this class of pricing problems, as well as for generalizations thereof. Computational testing indicates the advantage of our branch‐and‐price algorithm over various approaches that use commercial software packages. These tests also highlight the significant cost savings possible from integrating location with production and inventory decisions and demonstrate that the problem is rather insensitive to forecast errors associated with the demand streams. © 2011 Wiley Periodicals, Inc. Naval Research Logistics, 2011Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/86850/1/20458_ftp.pd

Multi-stage production with variable lot sizes and transportation of partial lots

This paper describes a model for a multi-stage production/inventory system where lots may be of different sizes. In addition, either completed lots or partial lots, called batches, may be transported to succeeding stages. The model incorporates constraints on lot and batch-sizes and thus provides a rather comprehensive set of possibilities for organizing a production/inventory system. A heuristic solution procedure is developed and is shown to be `close to optimal' by bounding.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/24742/1/0000164.pd

A Serious Video Game To Support Decision Making On Refugee Aid Deployment Policy

The success of refugee support operations depends on the ability of humanitarian organizations and governments to deploy aid effectively. These operations require that decisions on resource allocation are made as quickly as possible in order to respond to urgent crises and, by antici-pating future developments, remain adequate as the situation evolves. Agent-based modeling and simulation has been used to understand the progression of past refugee crises, as well as a way to predict how new ones will unfold. In this work, we tackle the problem of refugee aid deployment as a variant of the Robust Facility Location Problem (RFLP). We present a serious video game that functions as an interface for an agent-based simulation run with data from past refugee crises. Having obtained good approximate solutions to the RFLP by implementing a game that frames the problem as a puzzle, we adapted its mechanics and interface to correspond to refugee situations. The game is intended to be played by both subject matter experts and the general public, as a way to crowd-source effective courses of action in these situations

Spontaneously broken abelian Chern-Simons theories

A detailed analysis of Chern-Simons (CS) theories in which a compact abelian direct product gauge group U(1)^k is spontaneously broken down to a direct product H of (finite) cyclic groups is presented. The spectrum features global H charges, vortices carrying flux labeled by the elements of H and dyonic combinations. Due to the Aharonov-Bohm effect these particles exhibit toplogical interactions. The remnant of the U(1)^k CS term in the discrete H gauge theory describing the effective long distance physics of such a model is shown to be a 3-cocycle for H summarizing the nontrivial topological interactions cast upon the magnetic vortices by the U(1)^k CS term. It is noted that there are in general three types of 3-cocycles for a finite abelian gauge group H: one type describes topological interactions among vortices carrying flux w.r.t. the same cyclic group in the direct product H, another type gives rise to topological interactions between vortices carrying flux w.r.t. two different cyclic factors of H and a third type leading to topological interactions between vortices carrying flux w.r.t. three different cyclic factors. Among other things, it is demonstrated that only the first two types can be obtained from a spontaneously broken U(1)^k CS theory. The 3-cocycles that can not be reached in this way turn out to be the most interesting. They render the theory nonabelian and in general lead to dualities with planar theories with a nonabelian finite gauge group. In particular, the CS theory with finite gauge group H = Z_2 x Z_2 x Z_2 defined by such a 3-cocycle is shown to be dual to the planar discrete D_4 gauge theory with D_4 the dihedral group of order 8.Comment: 72+2 pages, LaTeX, 10 eps figures uuencoded. Postscript version also available at http://parthe.lpthe.jussieu.fr/~mdwp

Mixed planar and network single-facility location problems

We consider the problem of optimally locating a single facility anywhere in a network to serve both on-network and off-network demands. Off-network demands occur in a Euclidean plane, while on-network demands are restricted to a network embedded in the plane. On-network demand points are serviced using shortest-path distances through links of the network (e.g., on-road travel), whereas demand points located in the plane are serviced using more expensive Euclidean distances. Our base objective minimizes the total weighted distance to all demand points. We develop several extensions to our base model, including: (i) a threshold distance model where if network distance exceeds a given threshold, then service is always provided using Euclidean distance, and (ii) a minimax model that minimizes worst-case distance. We solve our formulations using the “Big Segment Small Segment” global optimization method, in conjunction with bounds tailored for each problem class. Computational experiments demonstrate the effectiveness of our solution procedures. Solution times are very fast (often under one second), making our approach a good candidate for embedding within existing heuristics that solve multi-facility problems by solving a sequence of single-facility problems. © 2016 Wiley Periodicals, Inc. NETWORKS, Vol. 68(4), 271–282 2016