43,844 research outputs found
1st Canadian Parachute Battalion in the Ardennes: A Personal Account, 23 December 1944 to 26 February 1945
Confidential Report on the Recent Bombing of Le Havre
Flight Lieutenant R.F. Delderfield was a RAF public relations officer in 1944 when he was ordered to the continent to cover the capture of Le Havre. Arriving about a week after the city was liberated, Delderfield spent two days examining the town and interviewing soldiers and civlians about their impressions of the RAF bombing of the city. The report is noteworthy for the attention it pays to the impact of the bombing of the local population. The RAF subsequently modified its plans for the bombing of Boulogne so that only defensive works around the perimeter of the city were attacked and a Royal Air Force officer was in direct communication with the aircraft during the attacks the ensure that accuracy was maintained
Configurations of Control: A Transaction Cost Approach
In this paper, I present a theory of management control based on Transaction Cost Economics.This theory seeks to integrate into a single framework a set of insights as to the natureof the organization's activities, the control problems that are inherent in these activities,and the unique problem solving potential of various archetypal control structures. The gistof the argument is that activities predictably differ in the control problems to which theygive rise, whereas control archetypes differ in their problem-solving ability, and thatalignments between the two can be explained by delineating the efficiency properties of thematch. This is a contingent configuration approach. It is a configuration theory in that itoffers a set of ideal types, conceived of as internally consistent and discriminating clustersof attributes from multiple dimensions that have a specific effect on control structureeffectiveness as the variable to be explained. But it is also a contingent approach in that itspecifies the conditions in which each of the archetypes is most effective.transaction cost economics;management control theory;configuration theory
Solving Lotsizing Problems on Parallel Identical Machines Using Symmetry Breaking Constraints
Production planning on multiple parallel machines is an interesting problem, both from a theoretical and practical point of view. The parallel machine lotsizing problem consists of finding the optimal timing and level of production and the best allocation of products to machines. In this paper we look at how to incorporate parallel machines in a Mixed Integer Programming model when using commercial optimization software. More specifically, we look at the issue of symmetry. When multiple identical machines are available, many alternative optimal solutions can be created by renumbering the machines. These alternative solutions lead to difficulties in the branch-and-bound algorithm. We propose new constraints to break this symmetry. We tested our approach on the parallel machine lotsizing problem with setup costs and times, using a network reformulation for this problem. Computational tests indicate that several of the proposed symmetry breaking constraints substantially improve the solution time, except when used for solving the very easy problems. The results highlight the importance of creative modeling in solving Mixed Integer Programming problems.Mixed Integer Programming;Formulations;Symmetry;Lotsizing
A CMOS rail-to-rail linear VI-converter
A linear CMOS VI-converter operating in strong inversion with a common-mode input range from the negative to the positive supply rail is presented. The circuit consists of three linear VI-converters based on the difference of squares principle. Two of these perform the actual V to I conversion, while the third changes the bias currents of the first two in response to changes in the input common-mode level. The resulting circuit has a large signal transconductance which is constant to within 3% over the entire common-mode input range. It can operate from a single supply voltage of 2.2 volt
The role of mass-movement in shore platform development along the Gisborne coastline, New Zealand
Tidal shore platforms form a conspicuous part of the coastal scenery north of Gisborne, New Zealand. Some of these platforms are being extended landward under present-day conditions. Present widening results primarily from cliff-retreat by mass-movement. The coincidence in distribution of areas of wave convergence, mass-movement and shore platforms suggests a genetic connection between these marine and subaerial process and response elements. Various types of mass-movement are involved in cliff-retreat, notably slumps, flows, debris slides and soil and rock falls. While the products of such mass-movement forms are removed by wave action, extensive boulder fields on some shore platforms indicate that removal is not always complete. Not all of the shore platforms on this coast are being widened at present. Widening has ceased where active mass-movement is not occurring
Optimal International Tax Coordination and Economic Integration: A Game-Theoretic Framework
The scope for optimal international coordination of indirect taxes is examined in a macroeconomic game-theoretic framework which encompasses two regionally integrated economies, which have a single goods market. In each country there are tax-financed non-tradeable public goods, while labor is immobile internationally. The analysis of both fixed and flexible wage versions of the model identifies a much wider spectrum of cooperative tax policies than has been previously recognized. In relation to non-cooperative Nash equilibria, cooperative Pareto-improving tax changes can entail not only uni-directional increases or decreases in rates, but also asymmetric directional changes. In particular, the constellation of such welfare improving tax changes is shown to depend critically on the countries'' relative preferences for private and public goods consumption, savings, as well as demand elasticity values relative to unit elasticity.econometrics;
Improved Lower Bounds For The Capacitated Lot Sizing Problem With Set Up Times
We present new lower bounds for the Capacitated Lot Sizing Problem with Set Up Times. We improve the lower bound obtained by the textbook Dantzig-Wolfe decomposition where the capacity constraints are the linking constraints. In our approach, Dantzig-Wolfe decomposition is applied to the network reformulation of the problem. The demand constraints are the linking constraints and the problem decomposes into subproblems per period containing the capacity and set up constraints. We propose a customized branch-and-bound algorithm for solving the subproblem based on its similarities with the Linear Multiple Choice Knapsack Problem. Further we present a Lagrange Relaxation algorithm for finding this lower bound. To the best of our knowledge, this is the first time that computational results are presented for this decomposition and a comparison of our lower bound to other lower bounds proposed in the literature indicates its high quality.Lagrange relaxation;Dantzig-Wolfe decomposition;capacitated lot sizing;lower bounds
Stellar and Gas Kinematics in the core and bar regions of M100
Original paper can be found at http://www.virtualjournals.org/proceedings/confproceed/783.jsp Copyright American Institute of Physics. DOI: 10.1063/1.2034969 [Full text of this article is not available in the UHRA]Two-dimensional maps of the stellar and gas kinematics of the bar and starbursting circumnuclear region in the barred spiral galaxy M100 are presented. In this progress report, we present maps of the total intensity, mean velocity and velocity dispersion for the stars and the gas. The gas velocity field shows significant kinematic signatures of gas streaming along the inner part of the bar, and across the miniature spiral arms in the nuclear pseudo-ring. The stellar velocity field, presented here for the first time, also shows non-circular motions. The gas velocity dispersion is notably smaller where the star formation occurs in the nuclear zone and HII regions. We outline our further plans with the data set.otherPeer reviewe
WILDCOMS
Disease and contaminants can both pose major risks to wildlife and human populations. Disease is a natural driver regulating the dynamics of wildlife populations, but
some diseases warrant particular attention because they (i) cause major mortalities that lead to population crashes, (eg., VHD in rabbits), (ii) threaten wildlife species of
high conservation concern (for example squirrelpox virus in red squirrels), or (iii) pose a potential threat to Man (eg., rabies, avian influenza). The wildlife Disease &
Contaminant Monoitoring and Surveillance (WILDCOMS) Network is a collaborative project among the major disease and contaminant monitoring schemes for vertebrate
wildlife that operate in the United Kingdom. These schemes are run by various government agencies and laboratories, research centres, institutes, and academia. The overall
aim is to establish a network which will foster and facilitate knowledge exchange, harmonisation towards best practice, and productive collaboration between: (i) partner
organisations; (ii) surveillance schemes and end-users. It will aim to provide end-users with an integrated overview of environmental disease and contaminant risk. The specific
objectives will be to develop the network and use it to address common challenges, specifically maximising dissemination of information to stakeholders and harmonisation towards common operational procedures to facilitate interaction and collaboration
- …
