181,634 research outputs found
An Optimization Model for Single-Warehouse Multi-Agents Distribution Network Problems under Varying of Transportation Facilities: A Case Study
The transportation cost of goods is the highest day-to-day operational cost associated with the
food industry sector. A company may be able to reduce logistics cost and simultaneously improve service
level by optimizing of distribution network. In reality, a company faces problems considering capacitated
transportation facilities and time constraint of delivery. In this paper, we develop a new model of order
fulfillment physical distribution to minimize transportation cost under limited of transportation facilities.
The first step is defined problem description. After that, we formulate a integer linear programming model
for the single-warehouse, multiple-agents considering varying of transportation facilities in multi-period
shipment planning. We analyze problems faced by company when should decide policy of distribution due to
varying of transportation facilities in volume, type of vehicle, delivery cost, lead time and ownership of
facilities. We assumed transportation costs are modeled with a linear term in the objective function. Then,
we solve the model with Microsoft Excel Solver 8.0 Version. Finally, we analyze the results with considering
amount of transportation facilities, volume usage and total transportation cost.
Keywords: physical distribution, shipment planning, integer linear programming, transportation cost,
transportation facilities
Abstract State Machines 1988-1998: Commented ASM Bibliography
An annotated bibliography of papers which deal with or use Abstract State
Machines (ASMs), as of January 1998.Comment: Also maintained as a BibTeX file at http://www.eecs.umich.edu/gasm
Virtual Evidence: A Constructive Semantics for Classical Logics
This article presents a computational semantics for classical logic using
constructive type theory. Such semantics seems impossible because classical
logic allows the Law of Excluded Middle (LEM), not accepted in constructive
logic since it does not have computational meaning. However, the apparently
oracular powers expressed in the LEM, that for any proposition P either it or
its negation, not P, is true can also be explained in terms of constructive
evidence that does not refer to "oracles for truth." Types with virtual
evidence and the constructive impossibility of negative evidence provide
sufficient semantic grounds for classical truth and have a simple computational
meaning. This idea is formalized using refinement types, a concept of
constructive type theory used since 1984 and explained here. A new axiom
creating virtual evidence fully retains the constructive meaning of the logical
operators in classical contexts.
Key Words: classical logic, constructive logic, intuitionistic logic,
propositions-as-types, constructive type theory, refinement types, double
negation translation, computational content, virtual evidenc
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