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Optimal Location of Radiation Therapy Centers With Respect to Geographic Access

INTERNATIONAL JOURNAL OF RADIATION ONCOLOGY BIOLOGY PHYSICS 2014年第4期89卷 745-755页

作者： Santibanez, Pablo Gaudet, Marc French, John Liu, Emma Tyldesley, Scott British Columbia Canc Agcy Dept Radiotherapy Vancouver Ctr Vancouver BC V5Z 4E6 Canada

Purpose: To develop a framework with which to evaluate locations of radiation therapy (RT) centers in a region based on geographic access. Methods and Materials: Patient records were obtained for all external beam radiation therapy started in 2011 for the province of British Columbia, Canada. Two metrics of geographic access were defined. The primary analysis was percentage of patients (coverage) within a 90-minute drive from an RT center (C90), and the secondary analysis was the average drive time (ADT) to an RT center. An integer programming model was developed to determine optimal center locations, catchment areas, and capacity required under different scenarios. Results: Records consisted of 11,096 courses of radiation corresponding to 161,616 fractions. Baseline geographic access was estimated at 102.5 minutes ADT (each way, per fraction) and 75.9% C90. Adding 2 and 3 new centers increased C90 to 88% and 92%, respectively, and decreased ADT by between 43% and 61%, respectively. A scenario in which RT was provided in every potential location that could support at least 1 fully utilized linear accelerator resulted in 35.3 minutes' ADT and 93.6% C90. Conclusions: The proposed framework and model provide a data-driven means to quantitatively evaluate alternative configurations of a regional RT system. Results suggest that the choice of location for future centers can significantly improve geographic access to RT. (C) 2014 Elsevier Inc.

关键词： EXTERNAL BEAM RADIATION THERAPY integer programming models Room temperature Radiotherapy abstract data types Linear accelerators secondary analysis

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ITERATIVE SIMULATION AND OPTIMIZATION APPROACH FOR JOB SHOP SCHEDULING

ITERATIVE SIMULATION AND OPTIMIZATION APPROACH FOR JOB SHOP ...

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Winter Simulation Conference

作者： Kulkarni, Ketki Venkateswaran, Jayendran Indian Inst Technol Ind Engn & Operat Res Room 308A Mech Engn Bldg Mumbai 400076 Maharashtra India

ISBN: (纸本)9781479974863

In this paper, we present an iterative scheme integrating simulation with an optimization model, for solving complex problems, viz., job shop scheduling. The classical job shop scheduling problem which is NP-Hard, has often been modelled as Mixed-integer programming (MIP) model and solved using exact algorithms (for example, branch-and-bound and branch-and-cut) or using meta-heuristics (for example, Genetic Algorithm, Particle Swarm Optimization and Simulated Annealing). In the proposed Iterative Simulation-Optimization (ISO)approach, we use a modified formulation of the scheduling problem where the operational aspects of the job shop are captured only in the simulation model. Two new decision variables, controller delays and queue priorities are used to introduce feedback constraints, that help exchange information between the two models. The proposed method is tested using benchmark instances from the OR library. The results indicate that the method gives near optimal schedules in a reasonable computational time.

关键词： computational complexity integer programming iterative methods job shop scheduling ISO approach MIP model NP-hard problem controller delay decision variables exact algorithms feedback constraints iterative simulation-optimization approach job shop scheduling problem meta-heuristics mixed-integer programming model queue priority simulation model Analytical models Computational modeling Job shop scheduling Linear programming Mathematical model Optimization Schedules Job shop scheduling Nondeterministic polynomial-time hard Computational modeling ANALYSIS models iterative methods integer programming Simulation models linear programming complexity classes Mathematical Model integer programming models

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A Middleware for Managing Non-Functional Requirements in Cloud PaaS

A Middleware for Managing Non-Functional Requirements in Clo...

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International Conference on Cloud and Autonomic Computing (ICCAC)

作者： Braubach, Lars Jander, Kai Pokahr, Alexander Univ Hamburg Dept Comp Sci Distributed Syst Grp Hamburg Germany

ISBN: (纸本)9781479958412

A key aspect of distributed applications in platformas-a-service clouds revolves around the definition of requirements for quality of service and the most efficient use of the available resources to achieve them. Matching both the requirements and resources represents a unique challenge: While requirements are generally defined in relatively abstract form and defined as system-wide parameters, the resources are concrete, low-level entities that, by themselves, are only of marginal influence on the requirements. In order to establish a relationship between these two requires both the agglomeration of properties into more abstract ones as well as refining requirements in more detailed, concrete ones, both of which can often only be done to a certain degree. This paper presents a vision how both aspects can be brought to the same level and introduces an approach enhancing component-based cloud applications with non-functional properties in the context of an integrated programming model. This allows developers of such applications to formally declare properties that may influence the application during runtime and document the expectations regarding non-functional aspects of the overall system. This can be used to ensure the health of the application and, in case requirements are violated, actions like the deployment of additional resources can be performed in order to alleviate any degradation of its non-functional state, either by evaluating, choosing and performing pre-defined actions automatically or by manual administrative intervention.

关键词： cloud computing middleware object-oriented programming administrative intervention cloud PaaS component-based cloud applications integrated programming model nonfunctional properties nonfunctional requirements platform-as-a-service clouds Concrete Current measurement Middleware Monitoring programming Quality of service Runtime cloud applications components platform-as-a-service programming model Middleware Cloud Computing Runtime Quality of service Electric current measurement Current measuring object oriented programming programming Concrete linear programming models integer programming models

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Interactive Depth First Algorithm for Oil Transportation Emergency Response Planning 14

Interactive Depth First Algorithm for Oil Transportation Eme...

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Simulation Multiconference

作者： Victor Romanov Ilya Moskovoy Kseniya Grigoryeva Russian Plekhanov University Information Systems in Economics and Management Department

ISBN: (纸本)9781632667335

In the event of an oil spill, an essential element of responding effectively to any adverse consequences is proper planning to define tasks, personnel, and resources necessary. The plan should include coordination with appropriate local, municipal, territorial, regional and federal departments, and include ground and air transportation, logistics support, spill reagent supply and repair equipment delivery. The task of automated planning-based on the concepts and principles of Artificial Intelligence (AI)-has become more urgent due to a dramatic rise in oil leak events. The idea of automated planning is not new. It is based on 50 years of research in the field, including predicate logic, situational calculus, dynamic and integer programming models STRIPS [19], PDDL [22] languages apply. The challenge is especially urgent for the petroleum and gas sectors of the Russian economy as the number of oil leaks has spiked to 28 thousand per year.

关键词： Automated planning Oil spill Pipeline rupture Interactive algorithm Restoring plans Situation calculus Depth first search Depth--first search oil spill hazard preparedness Petroleum Transportation integer programming models

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A solution approach based on Benders decomposition for the preventive maintenance scheduling problem of a stochastic large-scale energy system

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JOURNAL OF SCHEDULING 2013年第6期16卷 605-628页

作者： Lusby, Richard Muller, Laurent Flindt Petersen, Bjorn Tech Univ Denmark Dept Engn Management DK-2800 Lyngby Denmark

This paper describes a Benders decomposition-based framework for solving the large scale energy management problem that was posed for the ROADEF 2010 challenge. The problem was taken from the power industry and entailed scheduling the outage dates for a set of nuclear power plants, which need to be regularly taken down for refueling and maintenance, in such a way that the expected cost of meeting the power demand in a number of potential scenarios is minimized. We show that the problem structure naturally lends itself to Benders decomposition;however, not all constraints can be included in the mixed integer programming model. We present a two phase approach that first uses Benders decomposition to solve the linear programming relaxation of a relaxed version of the problem. In the second phase, integer solutions are enumerated and a procedure is applied to make them satisfy constraints not included in the relaxed problem. To cope with the size of the formulations arising in our approach we describe efficient preprocessing techniques to reduce the problem size and show how aggregation can be applied to each of the subproblems. Computational results on the test instances show that the procedure competes well on small instances of the problem, but runs into difficulty on larger ones. Unlike heuristic approaches, however, this methodology can be used to provide lower bounds on solution quality.

关键词： TWO-PHASE ENERGY SYSTEMS Power demand integer programming models Benders decomposition Power industry energy industries

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Scheduling the professional Ecuadorian football league by integer programming

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COMPUTERS & OPERATIONS RESEARCH 2013年第10期40卷 2478-2484页

作者： Recalde, D. Torres, R. Vaca, P. Escuela Politec Nacl Dept Math Quito Ecuador

A sports schedule sets the dates and venues of games among teams in a sports league. Constructing a sports schedule is a highly restrictive problem. The schedule must meet constraints due to regulations of a particular sports league federation and it must guarantee the participation of all teams on equal terms. Moreover, economic benefits of the teams and other agents involved in this activity are expected. Until 2011, the Ecuadorian football federation (FEF) had developed schedules for their professional football championship manually. In early 2011, the authors presented to the FEF authorities evidence that the use of mathematical programming to create feasible sports schedules could easily exceed the benefits obtained by the empirical method. Under this premise, this work presents an integer programming formulation, solved to optimality, for scheduling the professional football league in Ecuador, and also a heuristic approach based on three-phases for its solution. The schedules obtained met the expectations of the FEF and one of them was adopted as the official schedule for the 2012 edition of the Ecuadorian professional football championship. (C) 2013 Elsevier Ltd. All rights reserved.

关键词： Sports scheduling integer programming models Football

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Mathematical programming models for Scheduling in a CPU/FPGA Architecture with Communication Delay

Mathematical Programming Models for Scheduling in a CPU/FPGA...

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5th International Conference on Industrial Engineering and Systems Management (IEEE IESM)

作者： El Cadi, Abdessamad Ait Ben Atitallah, Rabie Artiba, Abdelhakim UVHC LAMIH UMR 8201 F-59313 Valenciennes 9 France

ISBN: (纸本)9782960053241

This paper deals with the mathematical modelling of a scheduling problem in a heterogeneous CPU/FPGA architecture with communication delay in order to minimize the makespan, C-max. This study was motivated by the quality of the available solvers for Mixed integer Program. The proposed model includes the communication delay constraints in a general form in a heterogeneous case depending at the same time on tasks and computing units. These constraints are linearized without adding any extra variables and the obtained linear model is reduced to make its solving with Cplex 12.5x faster. Computational results show that the proposed model is promising. For an average sized problem up to 50 tasks and 5 computing units the solving time under Cplex is about few seconds.

关键词： Mixed integer Communication Research Religious Missions Optimization methods mathematical programming ARCHITECTURE Building construction linear programming models integer programming models mathematical modeling linear models delay

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integer programming Approach for a Class of Staff Scheduling Problems - Schedule Optimization and Parameter Estimation

Integer Programming Approach for a Class of Staff Scheduling...

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6th International Conference on Soft Computing and Intelligent Systems (SCIS) / 13th International Symposium on Advanced Intelligence Systems (ISIS)

作者： Ohara, Makoto Tamaki, Hisashi Kobe Univ Grad Sch Law Nada Ku Rokko Dai 2-1 Kobe Hyogo 6578501 Japan Kobe Univ Grad Sch Syst Informat Nada Ku Kobe Hyogo 6578501 Japan

ISBN: (纸本)9781467327435;9781467327428

This paper introduces an integer programming approach for a class of staff scheduling problems which is applicable for various kinds of the problems by both adopting an optimization model and parameter estimation techniques based on a mathematical programming formulation. For a work in which a staff must change or rotate shifts, generally, a responsible personnel (e.g., a manager) makes a schedule (e.g., a dairy or a weekly staff assignment) in a manual way based on some experiences. It is very hard, however, to generate not only a good schedule but also a feasible one, due to several kinds of constraints and requirements should be satisfied. Here, it is the case that the constraints are not be completely clear because these have no evident boundary, which makes the scheduling problems more difficult. In this paper, first, the staff scheduling problem is formally described in a rather generalized form to apply a wide range of work types, and is formulated as a integer programming model. In this formulation, so many parameters concerning the desires of workers as well as the conditions on works are included. Then, some ways of identifying the parameters is investigated by utilizing the available information acquired extraction from the past staff schedules and listening from managers. In the case that the setting of the parameters is not suitable, a good schedule or even a practical schedule can not be obtained through the integer programming model. With respect to this point, some computational examples have been done in order to examine the reliability of the way of setting parameters as well as the model of optimizing schedule. Through the result of computational examples, the effectiveness and the potential of the proposed approach are confirmed.

关键词： staff integer programming models Parameter estimation integer programming manager Personnel

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Optimal Incremental Placement of PMUs for Power System Observability

Optimal Incremental Placement of PMUs for Power System Obser...

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IEEE Power and Energy Society General Meeting

作者： F. Wang W. Zhang P. Li Department of Electrical and Electronic Engineering The University of Hong Kong Hong Kong. Guangdong Power Dispatch Center of Guangdong Power Grid Co. Guangzhou Guangdong China.

ISBN: (纸本)9781467327275

This paper presents a series of optimization models for Phasor Measurement Unit (PMU) placement with new considerations. Extended from the formulations based on integer linear programming, issues concerning uncertainty propagation are discussed and an improved model is proposed to alleviate the impact. Furthermore, as it is more valuable in practice with incrementally placing PMUs, a multistage installation framework based on dynamic programming is developed. With a novel index introduced, the presented framework is implemented with uncertainty propagation controlled in a certain level for each stage. Unlike other available approaches, when processing the immediate stage in this paper, current and future installations are simultaneously considered rather than just making decisions from fixed PMU locations. Minimum number of PMUs is guaranteed meanwhile with each installation. In addition, a postprocessing optimization for selection from multiple solutions in integer programming models is also presented. The proposed models are tested in IEEE 14-, 30-, 57-and 118-bus systems. With the results analyzed and discussed, it indicates the improved model can limit the uncertainty propagation in a fixed level, and the proposed multistage framework could be employed as a practical strategy for PMU placement planning.

关键词： Optimal placement PMU state estimation uncertainty propagation observability incremental installation Phasor measurement units Uncertainty Propagation integer programming models placement Installations

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Simulation Study of Magnetic Resonance Imaging Examination Reservation Processes for Stroke Patients

Simulation Study of Magnetic Resonance Imaging Examination R...

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Chinese Control Conference

作者： Na GENG Xiaolan XIE Shanghai Jiao Tong University Ecole Nationale Superieure des Mines de Saint Etienne

ISBN: (纸本)9781467325813

The timely imaging examinations are most important for stroke patients to have the further appropriate diagnosis and treatment. We have proposed a contract-based Magnetic Resonance Imaging (MRI) reservation process in [1] in order to reduce their waiting time for MRI examinations. Contracted time slots (CTS) are especially reserved for stroke patients. Regular time slots (RTS) assignment policy is to assign some "unlucky" patients to RTS by keeping CTS queue length below a certain threshold. We further propose a reservation process in [2] in order to reduce the waiting time of these "unlucky" patients by utilizing the virtual CTS queue. RTS assignment policy is used to reserve additional RTS instead of assigning specific patients directly to RTS. This paper proposes a new reservation process without the virtual CTS queue. All times slots including CTS and RTS are used on FIFO (First In First Out) order. Computational results show that the improved method can greatly reduce the maximal waiting time and the deviation of average waiting time.

关键词： Reservation process Contracted time slots Regular time slots integer programming model Waiting time CTS stroke patient SLOT integer programming models first-in first-out Magnetic Resonance Imaging Room temperature Queue Stroke Patients

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