Load balancing a distributed/parallel system consists in allocating work (load) to its processors... more Load balancing a distributed/parallel system consists in allocating work (load) to its processors so that they have to process approximately the same amount of work or amounts in relation with their computation power. In this paper, we present a new distributed algorithm that implements the Most to Least Loaded (M2LL) policy. This policy aims at indicating pairs of processors, that will exchange loads, taking into account actually broken edges as well as the current load distribution in the system. The M2LL policy fixes the pairs of neighboring processors by selecting in priority the most loaded and the least loaded processor of each neighborhood. Our first and main result is that the M2LL distributed implementation terminates after at most (n/2)⋅d t iterations where n and d t are respectively the number of nodes and the degree of the system at time t. We then present a performance comparison between Generalized Adaptive Exchange (GAE) that uses M2LL and Relaxed First Order Scheme (RFOS), two load balancing algorithms for dynamic networks in which only link failures are considered. The comparison is carried out on a dedicated test bed that we have designed and implemented to this end. Our second important result is that although generating more communications, the GAE algorithm with the M2LL policy is faster than RFOS in balancing the system load. In addition, GAE M2LL is able to achieve a more stable balanced state than RFOS and scales well.
Recognition of musical instruments in multi-instrumental, polyphonic music is a difficult challen... more Recognition of musical instruments in multi-instrumental, polyphonic music is a difficult challenge which is yet far from being solved. Successful instrument recognition techniques in solos (monophonic or polyphonic recordings of single instruments) can help to deal with this task.
In this article we shall deal with automatic classification of sound samples and ways to improve ... more In this article we shall deal with automatic classification of sound samples and ways to improve the classification results: We describe a classification process which produces high classification success percentage (over 95% for musical instruments) and compare the results of three classification algorithms: Multidimensional Gauss, KNN and LVQ. Next, we introduce several algorithms to improve the sound database self-consistency by removing outliers: LOO, IQR and MIQR. We present our efficient process for Gradual Elimination of Descriptors using Discriminant Analysis (GDE) which improves a previous descriptor selection algorithm . It also enables us to reduce the computation complexity and space requirements of a sound classification process according to specific accuracy needs. Moreover, it allows finding the dominant separating characteristics of the sound samples in a database according to classification taxonomy. The article ends by showing that good classification results do not necessarily mean generalized recognition of the dominant sound source characteristics, but the classifier might actually be focused on the specific attributes of the classified database. By enriching the learning database with diverse samples from other databases we obtain a more general classifier. The dominant descriptors provided by GDE are then more closely related to what is supposed to be the distinctive characteristics of the sound sources. 1
Journal of Parallel and Distributed Computing, 1995
The Generalized Dimension Exchange (GDE) method is a fully distributed load balancing method that... more The Generalized Dimension Exchange (GDE) method is a fully distributed load balancing method that operates in a relaxation fashion for multicomputers with a direct communication network. It is parameterized by an exchange parameter that governs the splitting of load between a pair of directly connected processors during load balancing. An optimal would lead to the fastest convergence of the balancing process. Previous work has resulted in the optimal for the binary n-cubes. In this paper, we derive the optimal 's for the k-ary n-cube network and its variants|the ring, the torus, the chain, and the mesh. We establish the relationships between the optimal convergence rates of the method when applied to these structures, and conclude that the GDE method favors high dimensional k-ary n-cubes. We also reveal the superiority of the GDE method to another relaxation-based method, the di usion method.
The dimension exchange method (DEM) was initially proposed as a load-balancing algorithm for the ... more The dimension exchange method (DEM) was initially proposed as a load-balancing algorithm for the hypercube structure. It has been generalized to k-ary n-cubes. However the k-ary n-cube algorithm must take many iterations to converge to a balanced state. In this paper we propose a direct method to modify DEM. The new algorithm Direct Dimension Exchange (DDE) method, takes load average in every dimension to eliminate unnecessary load exchange. It balances the load directly without iteratively exchanging the load. This global approach is able to balance the load more accurately and much faster
We present the mathematical formalism and the verification methodology of the contract-based mode... more We present the mathematical formalism and the verification methodology of the contract-based model developed in the framework of the SPEEDS project. SPEEDS aims at developing methods and tools to support ldquospeculative designrdquo, a design methodology in which distributed designers develop different aspects of the overall system, in a concurrent but controlled way. Our generic mathematical model of contract supports this style of development. This is achieved by focusing on behaviors, by supporting the notion of ldquorich componentrdquo where functional and non-functional aspects of the system can be considered and combined, by representing rich components via their set of associated contracts, and by formalizing the process of component composition.
Some initial works have appeared that began to deal with the complicated task of musical instrume... more Some initial works have appeared that began to deal with the complicated task of musical instrument recognition in multi-instrumental music. Although quite a few papers have already appeared on instrument recognition of singleinstrument musical phrases ("solos"), the work on solo recognition is not yet exhausted. The knowledge of how to deal well with solos can also help in recognition of multiinstrumental music. We present a process for recognition of a set of instruments (bassoon, clarinet, flute, guitar, piano, cello and violin) in solo recordings, which yields a high recognition rate. Among the points that distinguish our work are a large and very diverse solo database -108 different solos, all by different performers, which apparently supplies a good generalization of the sound possibilities of each instrument, and a large collection of features -62 different feature types. Using our GDE feature selection algorithm we minimize the feature set and present the 20 features which are most suitable for solo recognition in real-time, almost without compromising the high recognition rate. The paper ends by demonstrating that our real-time feature set can also help performing instrument recognition in "duet" music.
We have prepared spherical non-agglomerated silver nanoparticles by an evaporation–condensation–d... more We have prepared spherical non-agglomerated silver nanoparticles by an evaporation–condensation–dilution/cooling technique. Silver was evaporated from a crucible in a tubular flow reactor. A porous tube diluter was used to quench the carrier gas at the outlet of the reactor to enhance the formation of small particles and to suppress agglomeration and other particle growth mechanisms. The number size distribution of the prepared particles was measured with a differential mobility analyser–condensation nucleus counter combination and the size and the shape of the particles were analysed with transmission electron microscope. The system was modelled using a sectional aerosol dynamics computer code to estimate the importance of different aerosol processes. In all conditions the particles obtained were non-agglomerated and spherical. The mean particle diameter varied from 4 to 10-nm depending on boundary conditions. From the modelling studies it can be concluded that the nucleation rate is the most important parameter controlling the final particle size.
Load balancing a distributed/parallel system consists in allocating work (load) to its processors... more Load balancing a distributed/parallel system consists in allocating work (load) to its processors so that they have to process approximately the same amount of work or amounts in relation with their computation power. In this paper, we present a new distributed algorithm that implements the Most to Least Loaded (M2LL) policy. This policy aims at indicating pairs of processors, that will exchange loads, taking into account actually broken edges as well as the current load distribution in the system. The M2LL policy fixes the pairs of neighboring processors by selecting in priority the most loaded and the least loaded processor of each neighborhood. Our first and main result is that the M2LL distributed implementation terminates after at most (n/2)⋅d t iterations where n and d t are respectively the number of nodes and the degree of the system at time t. We then present a performance comparison between Generalized Adaptive Exchange (GAE) that uses M2LL and Relaxed First Order Scheme (RFOS), two load balancing algorithms for dynamic networks in which only link failures are considered. The comparison is carried out on a dedicated test bed that we have designed and implemented to this end. Our second important result is that although generating more communications, the GAE algorithm with the M2LL policy is faster than RFOS in balancing the system load. In addition, GAE M2LL is able to achieve a more stable balanced state than RFOS and scales well.
Recognition of musical instruments in multi-instrumental, polyphonic music is a difficult challen... more Recognition of musical instruments in multi-instrumental, polyphonic music is a difficult challenge which is yet far from being solved. Successful instrument recognition techniques in solos (monophonic or polyphonic recordings of single instruments) can help to deal with this task.
In this article we shall deal with automatic classification of sound samples and ways to improve ... more In this article we shall deal with automatic classification of sound samples and ways to improve the classification results: We describe a classification process which produces high classification success percentage (over 95% for musical instruments) and compare the results of three classification algorithms: Multidimensional Gauss, KNN and LVQ. Next, we introduce several algorithms to improve the sound database self-consistency by removing outliers: LOO, IQR and MIQR. We present our efficient process for Gradual Elimination of Descriptors using Discriminant Analysis (GDE) which improves a previous descriptor selection algorithm . It also enables us to reduce the computation complexity and space requirements of a sound classification process according to specific accuracy needs. Moreover, it allows finding the dominant separating characteristics of the sound samples in a database according to classification taxonomy. The article ends by showing that good classification results do not necessarily mean generalized recognition of the dominant sound source characteristics, but the classifier might actually be focused on the specific attributes of the classified database. By enriching the learning database with diverse samples from other databases we obtain a more general classifier. The dominant descriptors provided by GDE are then more closely related to what is supposed to be the distinctive characteristics of the sound sources. 1
Journal of Parallel and Distributed Computing, 1995
The Generalized Dimension Exchange (GDE) method is a fully distributed load balancing method that... more The Generalized Dimension Exchange (GDE) method is a fully distributed load balancing method that operates in a relaxation fashion for multicomputers with a direct communication network. It is parameterized by an exchange parameter that governs the splitting of load between a pair of directly connected processors during load balancing. An optimal would lead to the fastest convergence of the balancing process. Previous work has resulted in the optimal for the binary n-cubes. In this paper, we derive the optimal 's for the k-ary n-cube network and its variants|the ring, the torus, the chain, and the mesh. We establish the relationships between the optimal convergence rates of the method when applied to these structures, and conclude that the GDE method favors high dimensional k-ary n-cubes. We also reveal the superiority of the GDE method to another relaxation-based method, the di usion method.
The dimension exchange method (DEM) was initially proposed as a load-balancing algorithm for the ... more The dimension exchange method (DEM) was initially proposed as a load-balancing algorithm for the hypercube structure. It has been generalized to k-ary n-cubes. However the k-ary n-cube algorithm must take many iterations to converge to a balanced state. In this paper we propose a direct method to modify DEM. The new algorithm Direct Dimension Exchange (DDE) method, takes load average in every dimension to eliminate unnecessary load exchange. It balances the load directly without iteratively exchanging the load. This global approach is able to balance the load more accurately and much faster
We present the mathematical formalism and the verification methodology of the contract-based mode... more We present the mathematical formalism and the verification methodology of the contract-based model developed in the framework of the SPEEDS project. SPEEDS aims at developing methods and tools to support ldquospeculative designrdquo, a design methodology in which distributed designers develop different aspects of the overall system, in a concurrent but controlled way. Our generic mathematical model of contract supports this style of development. This is achieved by focusing on behaviors, by supporting the notion of ldquorich componentrdquo where functional and non-functional aspects of the system can be considered and combined, by representing rich components via their set of associated contracts, and by formalizing the process of component composition.
Some initial works have appeared that began to deal with the complicated task of musical instrume... more Some initial works have appeared that began to deal with the complicated task of musical instrument recognition in multi-instrumental music. Although quite a few papers have already appeared on instrument recognition of singleinstrument musical phrases ("solos"), the work on solo recognition is not yet exhausted. The knowledge of how to deal well with solos can also help in recognition of multiinstrumental music. We present a process for recognition of a set of instruments (bassoon, clarinet, flute, guitar, piano, cello and violin) in solo recordings, which yields a high recognition rate. Among the points that distinguish our work are a large and very diverse solo database -108 different solos, all by different performers, which apparently supplies a good generalization of the sound possibilities of each instrument, and a large collection of features -62 different feature types. Using our GDE feature selection algorithm we minimize the feature set and present the 20 features which are most suitable for solo recognition in real-time, almost without compromising the high recognition rate. The paper ends by demonstrating that our real-time feature set can also help performing instrument recognition in "duet" music.
We have prepared spherical non-agglomerated silver nanoparticles by an evaporation–condensation–d... more We have prepared spherical non-agglomerated silver nanoparticles by an evaporation–condensation–dilution/cooling technique. Silver was evaporated from a crucible in a tubular flow reactor. A porous tube diluter was used to quench the carrier gas at the outlet of the reactor to enhance the formation of small particles and to suppress agglomeration and other particle growth mechanisms. The number size distribution of the prepared particles was measured with a differential mobility analyser–condensation nucleus counter combination and the size and the shape of the particles were analysed with transmission electron microscope. The system was modelled using a sectional aerosol dynamics computer code to estimate the importance of different aerosol processes. In all conditions the particles obtained were non-agglomerated and spherical. The mean particle diameter varied from 4 to 10-nm depending on boundary conditions. From the modelling studies it can be concluded that the nucleation rate is the most important parameter controlling the final particle size.
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Papers by Gde Ari