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15
Solving a RealTime Allocation Problem with Constraint Programming
, 2006
"... In this paper, we present an original approach (CPRTA for ”Constraint Programming for solving RealTime Allocation”) based on constraint programming to solve a static allocation problem of hard realtime tasks. This problem consists in assigning periodic tasks to distributed processors in the contex ..."
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Cited by 10 (0 self)
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In this paper, we present an original approach (CPRTA for ”Constraint Programming for solving RealTime Allocation”) based on constraint programming to solve a static allocation problem of hard realtime tasks. This problem consists in assigning periodic tasks to distributed processors in the context of fixed priority preemptive scheduling. CPRTA is built on dynamic constraint programming together with a learning method to find a feasible processor allocation under constraints. Two efficient new approaches are proposed and validated with experimental results. Moreover, CPRTA exhibits very interesting properties. It is complete (if a problem has no solution, the algorithm is able to prove it); it is nonparametric (it does not require specific tuning) thus allowing a large diversity of models to be easily considered. Finally, thanks to its capacity to explain failures, it offers attractive perspectives for guiding the architectural design process.
Transaction Routing for Distributed OLTP Systems: Survey and Recent Results
, 1996
"... Workloads in distributed database applications consist of queries and transactions. In order to address performance requirements, distributed transaction processing systems have to deal with two related issues: transaction routing and scheduling. Due to the distribution of data objects among nodes a ..."
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Cited by 5 (0 self)
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Workloads in distributed database applications consist of queries and transactions. In order to address performance requirements, distributed transaction processing systems have to deal with two related issues: transaction routing and scheduling. Due to the distribution of data objects among nodes and the access cost incurred by remote accesses, efficient transaction routing is an important consideration for overall system performance. Another important consideration is workflow scheduling and routing. Workflows are complex units of work consisting of multiple, possibly interdependent, transactions. In this survey, we discuss a number of different transaction routing mechanisms and their performance. 1. Introduction In database applications, typical workloads that need processing are database queries and transactions that may be issued in different sites of the distributed system. Database queries may be lengthy and resource consuming and result in readonly accesses to the database. ...
Incremental assignment problem
 Information Sciences
, 2007
"... In this paper we introduce the incremental assignment problem. In this problem, a new pair of vertices and their incident edges are added to a weighted bipartite graph whose maximum weighted matching is already known, and the maximum weighted matching of the extended graph is sought. We propose an O ..."
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Cited by 4 (0 self)
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In this paper we introduce the incremental assignment problem. In this problem, a new pair of vertices and their incident edges are added to a weighted bipartite graph whose maximum weighted matching is already known, and the maximum weighted matching of the extended graph is sought. We propose an O(V  2) algorithm for the problem.
Graph and Analytical Models for Emergency Evacuation
"... Abstract—CyberPhysicalHuman Systems (CPHS) combine sensing, communication and control to obtain desirable outcomes in physical environments for human beings, such as buildings or vehicles. A particularly important application area is emergency management. While recent work on the design and optimi ..."
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Cited by 4 (3 self)
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Abstract—CyberPhysicalHuman Systems (CPHS) combine sensing, communication and control to obtain desirable outcomes in physical environments for human beings, such as buildings or vehicles. A particularly important application area is emergency management. While recent work on the design and optimisation of emergency management schemes has relied essentially on discrete event simulation, which is challenged by the substantial amount of programming or reprogramming of the simulation tools, the scalability and the computing time needed to obtain useful performance estimates, this paper proposes an approach that offers fast estimates based on graph models and probability models. We show that graph models can offer insight into the critical areas in an emergency evacuaton and that they can suggest locations where sensor systems are particularly important and may require hardening. On the other hand, we also show that analytical models based on queueing theory can provide useful estimates of evacuation times and for routing optimisation. The results are illustrated with regard to the evacuation of a three story building.
Paretobased Soft RealTime Task Scheduling in Multiprocessor Systems
, 2000
"... We develop a new method to map (i.e. allocate and schedule) realtime applications into certain multiprocessor systems. Its objectives are 1) the minimization of the number of processors used and 2) the minimization of the deadline missing time. Given a parallel program with real time constraints an ..."
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Cited by 3 (0 self)
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We develop a new method to map (i.e. allocate and schedule) realtime applications into certain multiprocessor systems. Its objectives are 1) the minimization of the number of processors used and 2) the minimization of the deadline missing time. Given a parallel program with real time constraints and a multiprocessor system, our method finds schedules of the program in the system which satisfy all the real time constraints with minimum number of processors. The minimization is carried out through a Paretobased Genetic Algorithm which independently considers the both goals, because they are noncommensurable criteria. Experimental results show that our scheduling algorithm achieved better performance than previous ones. The advantage of our method is that the algorithm produces not a single solution but a family of solutions known as the Paretooptimal set, out of which designers can select optimal solutions appropriate for their environmental conditions.
Random neural network for emergency management
 In The Workshop on Grand Challenges in Modeling, Simulation and Analysis for Homeland Security
, 2010
"... Abstract—We consider decision problems in emergency management, such as simultaneously dispatching emergency teams to locations where incidents have occurred, and propose an algorithmic solution using the Random Neural Newtwork. This is an NPhard optimisation problem, but the approach we suggest is ..."
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Cited by 3 (2 self)
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Abstract—We consider decision problems in emergency management, such as simultaneously dispatching emergency teams to locations where incidents have occurred, and propose an algorithmic solution using the Random Neural Newtwork. This is an NPhard optimisation problem, but the approach we suggest is solved in polynomial time, and is also distributed so that each of the teams can potentially decide where to go based on shared information about the location of the incidents and of the teams, without consulting the others concerning the decision. The proposed approach is evaluated on a large number of instances of the problem, and we observe that it comes within 10 % of the cost achieved by the optimal solution. I.
Dynamic Adaptive Load Balancing Algorithms for High Performance Transaction Processing and their Evaluation
 Processing Deliverable WP3, T3.2, ESPRIT III P8144, URL: http://www.ics.forth.gr/proj/pleiades/projects/ LYDIA/year2deliv.html
, 1996
"... This paper discusses dynamic adaptive routing algorithms for multicomputers. A lot of work has been done in the past on that subject. Various algorithms have been designed both addressing general and rather specific engineering problems. In addition some theoretical formal work has been done. More ..."
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Cited by 2 (1 self)
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This paper discusses dynamic adaptive routing algorithms for multicomputers. A lot of work has been done in the past on that subject. Various algorithms have been designed both addressing general and rather specific engineering problems. In addition some theoretical formal work has been done. Moreover, extensive surveys have been given covering the wide range of the load distribution problem, which is often also addressed as the 'load balancing problem'.
Allocating Hard RealTime Tasks with Constraint Programming
, 2006
"... In this paper, we present an original approach (CPRTA for ”Constraint Programming for solving RealTime Allocation”) based on constraint programming to solve an allocation problem of hard realtime tasks. This problem consists in assigning periodic tasks to distributed processors in the context of f ..."
Abstract
 Add to MetaCart
In this paper, we present an original approach (CPRTA for ”Constraint Programming for solving RealTime Allocation”) based on constraint programming to solve an allocation problem of hard realtime tasks. This problem consists in assigning periodic tasks to distributed processors in the context of fixed priority preemptive scheduling. CPRTA is built on dynamic constraint programming together with a learning method to find a feasible processor allocation under constraints. Two new approaches are proposed for solving these kinds of problems which produce in their current version as acceptable performances as classical algorithms do. Some experimental results are given to show it. Moreover, CPRTA exhibits very interesting properties. It is complete — i.e., if a problem has no solution — the algorithm is able to prove it; it is nonparametric — i.e., it does not require specific initializations — thus allowing a large diversity of models to be easily considered. Finally, thanks to its capacity to explain failures, it offers attractive perspectives for guiding the architectural design process.
Heterogeneous Distributed Computing Systems with Memory and Communication Capacity Constraints
"... This paper addresses the problem of static load balancing in heterogeneous distributed computing systems taking into account both memory and communication capacity constraints. The load balancing problem is first modeled as an optimization problem. Then, a heuristic approach, called Adaptive Genetic ..."
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This paper addresses the problem of static load balancing in heterogeneous distributed computing systems taking into account both memory and communication capacity constraints. The load balancing problem is first modeled as an optimization problem. Then, a heuristic approach, called Adaptive Genetic Algorithm (AGA), is proposed to solve the problem. The performance of the proposed algorithm is evaluated by simulation studies on randomly generated instances and the results are compared with that obtained by applying both the Genetic Algorithm (GA) and the Simulated Annealing (SA). Also, the qualities of the results are compared with the optimal solutions that obtained by applying the BrachandBound (BB) algorithm.