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In the Search of Optimal Concurrency [article]

Vincent Gramoli, Petr Kuznetsov, Srivatsan Ravi
2016 arXiv   pre-print
In this paper, we treat this question formally by introducing the notion of a \emph{concurrency-optimal} implementation.  ...  We explore the concurrency properties of \emph{search} data structures which can be represented in the form of directed acyclic graphs exporting insert, delete and search operations.  ...  Measuring concurrency: pessimism vs. serializable optimism We explore the concurrency properties of a large class of search concurrent data structures.  ... 
arXiv:1603.01384v1 fatcat:i6bru3syt5eobhloeh4a2zllra

Improving convergence of evolutionary multi-objective optimization with local search: a concurrent-hybrid algorithm

Karthik Sindhya, Kalyanmoy Deb, Kaisa Miettinen
2011 Natural Computing  
In multiobjective optimization problems, the implementation of local search is a non-trivial task, as determining a goal for local search in presence of multiple conflicting objectives becomes a difficult  ...  Simulation results of the new concurrent-hybrid algorithm on several two to four-objective problems compared to a serial approach, clearly show the importance of local search in aiding a computationally  ...  Acknowledgments The support provided by the Academy of Finland (grant 118319) and the Jenny and Antti Wihuri foundation is highly appreciated.  ... 
doi:10.1007/s11047-011-9250-4 fatcat:54wumbubazfxtoausev2exjsuq

A correction to "Agent searching in a tree and the optimality of iterative deepening"

Pallab Dasgupta, P.P. Chakrabarti, S.C. DeSarkar
1995 Artificial Intelligence  
In the paper entitled "Agent searching in a tree and the optimality of iterative deepening" [2] we had presented three independent results, namely that there exists iterative deepening search strategies  ...  In this paper, we establish two results: l We first show that the iterative deepening strategy presented in [2] for an agent searching in m-concurrent rays is actually 1.58 times optimal in the worst case  ...  Let us consider the set of all possible iterative deepening strategies for the task of agent searching in m-concurrent rays.  ... 
doi:10.1016/0004-3702(95)00089-w fatcat:35ouefdzlfdytay6snwig5hgra

DeltaTree

Ibrahim Umar, Otto Johan Anshus, Phuong Hoai Ha
2015 Performance Evaluation Review  
We present DeltaTree, a practical locality-aware concurrent search tree that integrates both locality-optimization techniques from vEB-based trees, and concurrency-optimization techniques from highly-concurrent  ...  However, existing locality-aware search trees based on the van Emde Boas layout (vEB-based trees), poorly support concurrent (update) operations.  ...  ACKNOWLEDGMENTS This research work has received funding from the European Union Seventh Framework Programme (grant n • 611183) and from the Research Council of Norway (grant n • 231746/F20).  ... 
doi:10.1145/2796314.2745891 fatcat:yfbpco5m3vbezkgxaxyebytode

Model Optimization and Parameter Estimation with Nimrod/O [chapter]

David Abramson, Tom Peachey, Andrew Lewis
2006 Lecture Notes in Computer Science  
Optimization problems where the evaluation step is computationally intensive are becoming increasingly common in both engineering design and model parameter estimation.  ...  We describe a tool, Nimrod/O, that expedites the solution of such problems by performing evaluations concurrently, utilizing a range of platforms from workstations to widely distributed parallel machines  ...  In that situation the number of batches in the longest optimization is the main determinant of the total experiment time.  ... 
doi:10.1007/11758501_96 fatcat:27idkel3nvclzbyisflao6h3wu

On the hybridization of SMS-EMOA and local search for continuous multiobjective optimization

Patrick Koch, Oliver Kramer, Günter Rudolph, Nicola Beume
2009 Proceedings of the 11th Annual conference on Genetic and evolutionary computation - GECCO '09  
The motivation for the hybridization is a notion of combining the best of two worlds: evolutionary black box optimization and local search.  ...  We introduce a relay and a concurrent hybridization of the successful multiobjective optimizer SMS-EMOA and local optimization methods like Hooke & Jeeves and the Newton method.  ...  Jörg Fliege of the University of Southampton for providing the implementation of the multiobjective Newton and Steepest Descent method and Prof. Dr.  ... 
doi:10.1145/1569901.1569985 dblp:conf/gecco/KochKRB09 fatcat:x3mrs3vpnbfxjogbao4ozp4p4y

Concurrent Optimization of Mountain Railway Alignment and Station Locations with a Three-Dimensional Distance Transform Algorithm Incorporating a Perceptual Search Strategy

Hao Pu, Xiaoming Li, Paul Schonfeld, Wei Li, Jian Zhang, Jie Wang, Jianping Hu, Xianbao Peng
2021 IEEE Access  
In this study, the effectiveness of the method is verified through a real-world case study in a complex mountainous region.  ...  Especially in mountainous regions, the large 3-dimensional (3D) search spaces, complex terrain conditions, coupling constraints and infinite numbers of potential alternatives of this problem pose many  ...  in subsequent searches. (2) In order to satisfy the requirements of concurrent optimization, a combined-alignment-station 3D search neighboring mask is developed and employed in the search process along  ... 
doi:10.1109/access.2021.3061587 fatcat:y6fje6t5cjctbhe2ewfzyxenky

A Reliable Web Services Selection Method for Concurrent Requests

Guiming Lu, Yan Hai, Yaoyao Sun
2014 TELKOMNIKA (Telecommunication Computing Electronics and Control)  
This paper aims at solving the Web Services selection for concurrent requests and developing a global optimal selection method for multiple similar service requesters to optimize the system resources.  ...  Furthermore, to enhance the efficiency of ISCO, the elite strategy is used in ISCO algorithm. We evaluate performance of the ISCO algorithm and the selection method through simulations.  ...  The algorithm description of Web services selection for concurrency requests In Web service selection optimization problems for concurrent users' demands, the knowledge points corresponds to the sequence  ... 
doi:10.12928/telkomnika.v12i4.786 fatcat:frryiypfjngqtegcdep5ccbdjm

Evolutionary Multiobjective Optimization including Practically Desirable Solutions

Miyako Sagawa, Natsuki Kusuno, Hernán Aguirre, Kiyoshi Tanaka, Masataka Koishi
2017 Advances in Operations Research  
One method searches with one population in the expanded space, whereas the other one uses two populations to search concurrently in the original and expanded space.  ...  In many practical situations the decision-maker has to pay special attention to decision space to determine the constructability of a potential solution, in addition to its optimality in objective space  ...  Conflicts of Interest The authors declare that there are no conflicts of interest regarding the publication of this paper.  ... 
doi:10.1155/2017/9094514 fatcat:7eo3uixwlzebndz47t7jmmyjfm

Support Concurrent Queries in Multiuser CBIR Systems

Danzhou Liu, Kien A. Hua
2007 2007 IEEE 23rd International Conference on Data Engineering  
Our experimental results, based on the Corel dataset, indicates that the proposed optimization can significantly reduce average response time in a multiuser environment.  ...  In this paper, we propose a generalized query model suitable for expressing queries of different types, and investigate efficient processing techniques for this new framework.  ...  There are two general types of search in CBIR: target search and category search. The goal of target search is to find a specific (target) image (e.g., a registered logo).  ... 
doi:10.1109/icde.2007.369016 dblp:conf/icde/LiuH07 fatcat:ildqug5yz5g65bqbnan43pvi6e

Prediction-Based Power-Performance Adaptation of Multithreaded Scientific Codes

M. Curtis-Maury, F. Blagojevic, C.D. Antonopoulos, D.S. Nikolopoulos
2008 IEEE Transactions on Parallel and Distributed Systems  
The use of prediction reduces the overhead of searching the optimization space while achieving near-optimal performance and power savings.  ...  Using our model, we develop a prediction-driven, phase-aware runtime optimization scheme that throttles concurrency so that power consumption can be reduced and performance can be set at the knee of the  ...  Department of Energy (grants DE-FG02-06ER25751, DE-FG02-05ER25689) and Virginia Tech.  ... 
doi:10.1109/tpds.2007.70804 fatcat:ruek3ipnjjcyrk5ch5pxngsd4a

Concurrent stochastic methods for global optimization

Richard H. Byrd, Cornelius L. Dert, Alexander H. G. Rinnooy Kan, Robert B. Schnabel
1990 Mathematical programming  
The global optimization problem, finding the lowest minimizer of a nonlinear function of several variables that has multiple local minimizers, appears well suited to concurrent computation.  ...  Concurrency is achieved by partitioning the work of each of the three main parts of the algorithm, sampling, local minimization start point selection, and multiple local minimizations, among the processors  ...  Acknowledgement We thank Betty Eskow for her extensive help in continuing computer testing of our parallel algorithms after Cees Deft returned to the Netherlands.  ... 
doi:10.1007/bf01585724 fatcat:6xiprnc2kfghjatbhe2edsfzfq

Tackling the Testing and Verification of Multicore and Concurrent Software as a Search Problem [chapter]

Lionel C. Briand
2012 Lecture Notes in Computer Science  
real data and two different objective functions But optimal solutions were found shortly after the search started, even if the search took a much more time to terminate It took a significant amount of  ...  Objective • Model-based performance analysis of real-time, concurrent systems: practical solutions based on standards and search/optimization Optimization Conceptual Model (Guidelines) System  ...  Data Races • Fall under umbrella of race conditions • Result from unsynchronized access of threads to same memory location as either reader or writer threads • Protected access (e.g., monitors) not always  ... 
doi:10.1007/978-3-642-31202-1_2 fatcat:dgz7ow7rnjfgdaqeocobuhkdqq

RSCS: A Parallel Simplex Algorithm for the Nimrod/O Optimization Toolset

Andrew Lewis, David Abramson, Tom Peachey
2006 Scientific Programming  
When tested on a range of problems drawn from real-world applications in science and engineering, this reducing set concurrent simplex (RSCS) variant of the Nelder-Mead algorithm compared favourably with  ...  A reducing set of simplex vertices are used to derive search directions generally closely aligned with the local gradient.  ...  Comparing the search directions illustrated in Figure 4 with the concurrent search directions of Figure 3 , it may be noted that the search directions generated by RSCS are more likely to be downhill  ... 
doi:10.1155/2006/906394 fatcat:5cgwzffyfvb4ld5dd42urzdvvm

GreenBST: Energy-Efficient Concurrent Search Tree [chapter]

Ibrahim Umar, Otto Anshus, Phuong Ha
2016 Lecture Notes in Computer Science  
Our experimental evaluation using the recent implementation of non-blocking binary search trees, highly concurrent B-trees, conventional vEB trees, as well as the portably scalable concurrent trees shows  ...  However, existing locality-aware search trees such as ones based on the van Emde Boas layout (vEB-based trees), poorly support concurrent (update) operations while existing highly-concurrent search trees  ...  Acknowledgments This work has received funding from the European Union Seventh Framework Programme (EXCESS project, grant n • 611183) and from the Research Council of Norway (PREAPP project, grant n •  ... 
doi:10.1007/978-3-319-43659-3_37 fatcat:fcoolwijevda3lvvb7ow4x4zaq
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