4,866 research outputs found
Recent Advances in Graph Partitioning
We survey recent trends in practical algorithms for balanced graph
partitioning together with applications and future research directions
Scalable Parallel Numerical Constraint Solver Using Global Load Balancing
We present a scalable parallel solver for numerical constraint satisfaction
problems (NCSPs). Our parallelization scheme consists of homogeneous worker
solvers, each of which runs on an available core and communicates with others
via the global load balancing (GLB) method. The parallel solver is implemented
with X10 that provides an implementation of GLB as a library. In experiments,
several NCSPs from the literature were solved and attained up to 516-fold
speedup using 600 cores of the TSUBAME2.5 supercomputer.Comment: To be presented at X10'15 Worksho
Quafu-Qcover: Explore Combinatorial Optimization Problems on Cloud-based Quantum Computers
We present Quafu-Qcover, an open-source cloud-based software package designed
for combinatorial optimization problems that support both quantum simulators
and hardware backends. Quafu-Qcover provides a standardized and complete
workflow for solving combinatorial optimization problems using the Quantum
Approximate Optimization Algorithm (QAOA). It enables the automatic modeling of
the original problem as a quadratic unconstrained binary optimization (QUBO)
model and corresponding Ising model, which can be further transformed into a
weight graph. The core of Qcover relies on a graph decomposition-based
classical algorithm, which enables obtaining the optimal parameters for the
shallow QAOA circuit more efficiently. Quafu-Qcover includes a specialized
compiler that translates QAOA circuits into physical quantum circuits capable
of execution on Quafu cloud quantum computers. Compared to a general-purpose
compiler, ours generates shorter circuit depths while also possessing better
speed performance. The Qcover compiler can establish a library of qubits
coupling substructures in real time based on the updated calibration data of
the superconducting quantum devices, ensuring that the task is executed on
physical qubits with higher fidelity. The Quafu-Qcover allows us to retrieve
quantum computer sampling result information at any time using task ID,
enabling asynchronous processing. Besides, it includes modules for result
preprocessing and visualization, allowing for an intuitive display of the
solution to combinatorial optimization problems. We hope that Quafu-Qcover can
serve as a guiding example for how to explore application problems on the Quafu
cloud quantum computersComment: Comments are welcome
Partitioning problems in parallel, pipelined and distributed computing
The problem of optimally assigning the modules of a parallel program over the processors of a multiple computer system is addressed. A Sum-Bottleneck path algorithm is developed that permits the efficient solution of many variants of this problem under some constraints on the structure of the partitions. In particular, the following problems are solved optimally for a single-host, multiple satellite system: partitioning multiple chain structured parallel programs, multiple arbitrarily structured serial programs and single tree structured parallel programs. In addition, the problems of partitioning chain structured parallel programs across chain connected systems and across shared memory (or shared bus) systems are also solved under certain constraints. All solutions for parallel programs are equally applicable to pipelined programs. These results extend prior research in this area by explicitly taking concurrency into account and permit the efficient utilization of multiple computer architectures for a wide range of problems of practical interest
Scalable Parallel Numerical CSP Solver
We present a parallel solver for numerical constraint satisfaction problems
(NCSPs) that can scale on a number of cores. Our proposed method runs worker
solvers on the available cores and simultaneously the workers cooperate for the
search space distribution and balancing. In the experiments, we attained up to
119-fold speedup using 256 cores of a parallel computer.Comment: The final publication is available at Springe
Load-Balanced Bottleneck Objectives in Process Mapping
We propose a new problem formulation for graph partitioning that is tailored to the needs of time-critical simulations on modern heterogeneous supercomputers
A Survey of Pipelined Workflow Scheduling: Models and Algorithms
International audienceA large class of applications need to execute the same workflow on different data sets of identical size. Efficient execution of such applications necessitates intelligent distribution of the application components and tasks on a parallel machine, and the execution can be orchestrated by utilizing task-, data-, pipelined-, and/or replicated-parallelism. The scheduling problem that encompasses all of these techniques is called pipelined workflow scheduling, and it has been widely studied in the last decade. Multiple models and algorithms have flourished to tackle various programming paradigms, constraints, machine behaviors or optimization goals. This paper surveys the field by summing up and structuring known results and approaches
- …