INESC-ID

About: INESC-ID is a nonprofit organization based out in Lisbon, Portugal. It is known for research contribution in the topics: Field-programmable gate array & Control theory. The organization has 932 authors who have published 2618 publications receiving 37658 citations.

Flexible SLAs in the Cloud with a Partial Utility-Driven Scheduling Architecture

Abstract: Current clouds SLAs include compensation for customers (i.e. resource renters) with credits when average availability drops below a certain point. However, this credit scheme is too inflexible because consumers lose a non measurable quantity of performance and are only compensated later (i.e. in the next charging cycle). We propose to schedule cloud isolation and execution units, i.e. virtual machines (VMs), driven by the partial utility of applying a certain amount of resources (CPU, memory or bandwidth) to a given VM. This partial utility metric, specified by the customer, allows the provider to transfer resources between VMs. This is particularly relevant for private clouds where resources are not so abundant. We have defined a cost model that incorporates the partial utility the client gives to a certain level of depreciation when VMs are allocated in an over commit environment. CloudSim, a state of the art cloud simulator, was extended to support our partial utility-driven scheduling model. Using simulation scenarios with synthetic and real workloads, we show that our proposed scheduling strategy brings benefits to providers (i.e. revenue, resource utilization) and clients (i.e. workloads' execution time) by incorporating a SLA-based depreciation of computational power, allowing for more VMs to be allocated.

Geometric differential evolution on the space of genetic programs

Abstract: Geometric Differential Evolution (GDE) is a very recently introduced formal generalization of traditional Differential Evolution (DE) that can be used to derive specific GDE for both continuous and combinatorial spaces retaining the same geometric interpretation of the dynamics of the DE search across representations. In this paper, we derive formally a specific GDE for the space of genetic programs. The result is a Differential Evolution algorithm searching the space of genetic programs by acting directly on their tree representation. We present experimental results for the new algorithm.

An RNS based Specific Processor for Computing the Minimum Sum-of-Absolute-Differences

Abstract: The sum of absolute differences (SAD) is a distance metric commonly used to determine the similarity between two data sets. A very recent method for directly comparing the magnitude of two numbers represented in residue number systems (RNS) leads to the possibility of using modular arithmetic to compute the SAD. In this paper we propose an efficient hardware SAD unit that computes this Manhattan distance independently of each RNS channel. Therefore, the processing time can be reduced by simultaneously exploiting the carry-free characteristic of the modular arithmetic and the new method proposed by the authors of this paper to compare the magnitude of numbers in RNS. The proposed architecture is suitable to implement SAD units in application specific integrated circuit (ASIC) and in field programmable gate array (FPGA). In order to evaluate the performance of the proposed structures a hardware processor for computing the minimum SAD was implemented in a FPGA and ASIC. From the experimental results it was possible to obtain operating frequencies above 200 MHz for XILINX FPGAs XC2VP50-7 and XC4VLX80-12, and 300 MHz for the ASIC implementation. These results allow the implementation of real-time motion estimators for high resolution images according to the most recent standards for video coding.

Keyphrase Cloud Generation of Broadcast News

Abstract: This paper describes an enhanced automatic keyphrase extraction method applied to Broadcast News. The keyphrase extraction process is used to create a concept level for each news. On top of words resulting from a speech recognition system output and news indexation and it contributes to the generation of a tag/keyphrase cloud of the top news included in a Multimedia Monitoring Solution system for TV and Radio news/programs, running daily, and monitoring 12 TV channels and 4 Radios.