Performance Study

This study assesses the interaction of the postural control system and the production of expressive vocal behavior during speech and singing. In particular, we focus on the head, whose motions have been implicated for both postural control and spoken language production. How ...

The high resolution research tomograph (HRRT) is one of the most complex existing Positron Emission Tomographs: it is the only human size scanner capable of decoding the depth of the γ-ray interaction in the crystal, using a lutetium LSO/LYSO phoswitch detector arrangement. In this study we determined basic scanner hardware characteristics, such as scanner data acquisition stability, and their variability across eleven centres. In addition a subset of the NEMA NU-2001 standards measurements was performed. We found (i) significant variability in the DOI decoding results between centres, (ii) a trend toward an increasing number of detected true coincident events as a function of elapsed time from scanner calibration likely due to a shifting energy spectrum, (iii) a count-rate dependent layer identification, (iv) scatter fraction ranging from ∼ 42% to 54% where the variability was partly related to the shifting of the energy spectrum, (v) sensitivity ranging from ∼ 5.5% to 6.5% across centres, (vi) resolution of ∼ (2.5mm) 3 , fairly consistent across centres, (vii) image quality which is very comparable to other scanners.

Determining if there is enough bandwidth to allow admit a new flow into a wireless network is a complex task. To solve this problem, various methods have been proposed for estimating bandwidth. We study through simulations the performance of a new algorithm that has theoretical guarantees to correctly determine the available bandwidth without disturbing other flows that are currently being served. Specifically, we studied how the selection of the algorithm parameters affects its speed of convergence and accuracy of the estimates of available bandwidth. The results confirm the theoretical results and are used to determine the best parameters for rapid convergence with minimal estimation error.

NUMA nodes are potentially powerful but taking benefit of their capabilities is challenging due to their architecture (multiple computing cores, advanced memory hierarchy). They are nonetheless one of the key components to enable processing the ever growing amount of data produced by scientific simulations. In this paper we study the parallelization of patterns commonly used in VTK algorithms and propose a new multi-threaded plugin for VTK that eases the development of parallel multi-core VTK filters. We specifically focus on task-based approaches and show that with a limited code refactoring effort we can take advantage of NUMA node capabilities. We experiment our patterns on a transform filter, base isosurface extraction filter and a min/max tree accelerated isosurface extraction. We support 3 programming environments, OpenMP, Intel TBB and X-KAAPI, and propose different algorithmic refinements according to the capabilities of the target environment. Results show that we can speed execution up to 30 times on a 48-core machine.

Determining if there is enough bandwidth to allow admit a new flow into a wireless network is a complex task. To solve this problem, various methods have been proposed for estimating bandwidth. We study through simulations the performance of a new algorithm that has theoretical guarantees to correctly determine the available bandwidth without disturbing other flows that are currently being served. Specifically, we studied how the selection of the algorithm parameters affects its speed of convergence and accuracy of the estimates of available bandwidth. The results confirm the theoretical results and are used to determine the best parameters for rapid convergence with minimal estimation error.

Cognitive musicology is a psychological domain of music which attempts to proximity several interpretations as notation in a score, analysis, performance, and perception. The previous study of the authors developes the interdisciplinary analysis method of tension design combining music theoretical and perception approaches (investigating contemporary music). In this study we observe different performances of "Sula" (Thaw, 1999) by Estonian composer Helena Tulve (1972). We investigate the impact of performance style of different conductors (Toomas Vavilov, Paul Mägi) and orchestras (ERSO, Orchestra of Estonian National Opera) on the perception-based tension design of the piece and how it is connected to score-based tension design. Observed performances reveal concordance in the overall shape of culmination points (CP-s) of final sections. Most significant for both conductors is the difference of approaching CP-s: Vavilov points out peaks, Mägi builds blending plateaux. Reputedly listeners perceive the overall contour of perception-based tension design individually, but also revealing concordance in significant moments of tension design. This study reveals, that Vavilov's sharp pointing of CP-s corresponds more frequently to expectations of the listeners, while Mägi "overrides" the "real" CP-s, focusing more on blending increasing and releasing phases. Vavilov's interpretation shows more segmentation, while Mägi guides the listeners toward one main CP (13'08''). He also "overrides" the crucial CP (10'54''), which is as a composed out caesura (bar 181) clearly shown in the score. Vavilov accentuates this crucial CP (13'16''). But the listener's grasping of the conductors general idea of overall TD depends on the type of analytical or esemplastic perception.

Cognitive musicology is a psychological domain of music which attempts to proximity several interpretations as notation in a score, analysis, performance, and perception. The previous study of the authors developes the interdisciplinary analysis method of tension design combining music theoretical and perception approaches (investigating contemporary music). In this study we observe different performances of "Sula" (Thaw, 1999) by Estonian composer Helena Tulve (1972). We investigate the impact of performance style of different conductors (Toomas Vavilov, Paul Mägi) and orchestras (ERSO, Orchestra of Estonian National Opera) on the perception-based tension design of the piece and how it is connected to score-based tension design. Observed performances reveal concordance in the overall shape of culmination points (CP-s) of final sections. Most significant for both conductors is the difference of approaching CP-s: Vavilov points out peaks, Mägi builds blending plateaux. Reputedly listeners perceive the overall contour of perception-based tension design individually, but also revealing concordance in significant moments of tension design. This study reveals, that Vavilov's sharp pointing of CP-s corresponds more frequently to expectations of the listeners, while Mägi "overrides" the "real" CP-s, focusing more on blending increasing and releasing phases. Vavilov's interpretation shows more segmentation, while Mägi guides the listeners toward one main CP (13'08''). He also "overrides" the crucial CP (10'54''), which is as a composed out caesura (bar 181) clearly shown in the score. Vavilov accentuates this crucial CP (13'16''). But the listener's grasping of the conductors general idea of overall TD depends on the type of analytical or esemplastic perception.

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Routing protocols for multi hop wireless networks have used shortest path routing to obtain best paths to destinations and do not consider traffic load or delay as an factor in the selection of routes. So motivated, we address the issue of designing a multipath routing protocol that is generally applicable even when there are more sources and also we can use link state routing protocol to reduce the impedence. We develop a protocol that adaptively equalizes the mean delay along all utilized routes from a source to destination and does not utilize any routes that have greater mean delay. This is the property satisfied by a system in War drop equilibrium. We also address the architectural challenges confronted in the software implementation of a multipath, delayfeedback-based, probabilistic routing algorithm. Round trip time is taken into account so that we can avoid the duplicate packets from outgoing lines. Age field is included for the sequence number and reduce once per second the...

This research work was carried out to compare the performance of manual reaper against manual harvesting method for rice and wheat. The average field capacity of manual reaper was 0.3482 ha/day for rice and 0.3236 ha/day for wheat with fuel consumption of 0.755 L petrol/h and 0.625 L petrol/h respectively. In manual harvesting, the average field capacity was 0.0312 ha/man-day and 0.0452 ha/man-day for rice and wheat respectively. It was revealed that using manual reaper, harvesting cost could be saved 58% for rice and 53% for wheat, consequently harvesting of selected crops by reaper was efficient than manual harvesting. It was also observed that if manual reaper works below break-even point 0.32 ha and 0.52 ha for rice and wheat respectively, it would not be economically feasible to farmers. Finally, manual reaper could be suggested as better mechanization for harvesting of rice and wheat, cultivated on fragmented lands.

Offensive odours from industrial and sanitary environmental engineering plants can cause problems, such as sleep disorders, migraine and loss of appetite, also considering that they address the quality of life. Odour emission characterization is currently discussed in international literature as to determine its most feasible implementation. A method for continuous odour monitoring is based on the use of electronic noses. Electronic nose is an instrument which comprises an array of electronic chemical sensors with partial specificity and an appropriate pattern recognition system, capable of recognizing simple or complex odours. Aim of this work is to numerically analyze the performance of a sensor chamber in order to improve sensor response signals in terms of stability, reproducibility and response time. Comparative results are based on the location of four different diffusers. The numerical analysis was performed by a computational fluid dynamic (CFD) software in order to guarantee that all sensors are exposed to the same chemical sample under the same experimental conditions for the same time, reducing the presence of stagnant or recirculating regions.

Response time is a key factor of any e-Commerce application, and a set of solutions have been proposed to provide low response time despite network congestions or failures. Being them mostly based on caching of Web objects and replication of DBMS managed data at the edges, or at intermediate points, of the Web infrastructure, they well fit the requirements of client requests only performing read access to (dynamic) application data. However, these solutions typically require any update request to be redirected to the origin DBMSs, which act as the masters within the replication scheme. Hence, update requests typically do not take advantage from data replication and related client proximity. In order to alleviate the effects of network congestions or failures, we have proposed a multi-path protocol that, depending on current network conditions, increases the likelihood for the update request to be processed along a responsive (e.g. a failure free) network path in between the client location and the origin DBMS sites. In this paper we present an extensive simulation study of the effects of such a multi-path approach on the client perceived response time. The study relies on both Brite generated network topologies and the NLANR graph. Also, well known realistic TCP models are used to capture the effects of network delays during both normal and anomalous (i.e. packet loss affected) operation mode. By the results, our multi-path approach increases the likelihood for the system to maintain an adequate level of service under a wide range of network operation modes, hence including anomalous ones, which is instead not achieved in case of the standard approach not leveraging path-diversity for handling update requests at the origin (master) sites.

Cognitive musicology is a psychological domain of music which attempts to proximity several interpretations as notation in a score, analysis, performance, and perception. The previous study of the authors developes the interdisciplinary analysis method of tension design combining music theoretical and perception approaches (investigating contemporary music). In this study we observe different performances of "Sula" (Thaw, 1999) by Estonian composer Helena Tulve (1972). We investigate the impact of performance style of different conductors (Toomas Vavilov, Paul Mägi) and orchestras (ERSO, Orchestra of Estonian National Opera) on the perception-based tension design of the piece and how it is connected to score-based tension design. Observed performances reveal concordance in the overall shape of culmination points (CP-s) of final sections. Most significant for both conductors is the difference of approaching CP-s: Vavilov points out peaks, Mägi builds blending plateaux. Reputedly listeners perceive the overall contour of perception-based tension design individually, but also revealing concordance in significant moments of tension design. This study reveals, that Vavilov's sharp pointing of CP-s corresponds more frequently to expectations of the listeners, while Mägi "overrides" the "real" CP-s, focusing more on blending increasing and releasing phases. Vavilov's interpretation shows more segmentation, while Mägi guides the listeners toward one main CP (13'08''). He also "overrides" the crucial CP (10'54''), which is as a composed out caesura (bar 181) clearly shown in the score. Vavilov accentuates this crucial CP (13'16''). But the listener's grasping of the conductors general idea of overall TD depends on the type of analytical or esemplastic perception.

In this document, we put forward PaSTeL, an engine dedicated to parallel algorithms. PaSTeL oers both a programming model, to build parallel algorithms and an execution model based on work-stealing. Special care has been taken on using optimized thread activation and synchronization mechanisms. In order to illustrate the use of PaSTeL a subset of the STL's algorithms was implemented, which were also used on performance experiments. PaSTeL's performance is evaluated on a laptop computer using two cores, but also on a 16 cores platform. PaSTeL shows better performance than other implementations of the STL, especially on small datasets.

Landfill leachate emerges as a promising feedstock for microbial fuel cells (MFCs). In the present investigation, direct airbreathing cathode-based MFCs are fabricated to investigate the potential of landfill leachate. Three MFCs that have different cathode areas are fabricated and investigated for 17 days under open circuit conditions. The maximum open circuit voltage (OCV) is observed to be as high as 1.29 V. The maximum cathode area specific power density achieved in the reactor is 1513 mW m-2. Further studies are under progress to understand the origin of high OCV obtained from landfill leachate-based MFCs.

Accelerators, such as field programmable gate arrays (FPGAs) and graphics processing units (GPUs), are special purpose processors designed to speed up computeintensive sections of applications. FPGAs are highly customizable, while GPUs provide massive parallel execution resources and high memory bandwidth. In this paper, we compare the performance of these architectures, presenting a performance study of SEAL, a fast, software-oriented encryption algorithm on a Virtex-6 FPGA, a Graphics Processor Unit (GPU), and Intel Core i7, a 2-way hyper-threaded, 4-core processor. We show that each platform has relative competitive advantages in encrypting an input plaintext using SEAL.

The high resolution research tomograph (HRRT) is one of the most complex existing Positron Emission Tomographs: it is the only human size scanner capable of decoding the depth of the γ-ray interaction in the crystal, using a lutetium LSO/LYSO phoswitch detector arrangement. In this study we determined basic scanner hardware characteristics, such as scanner data acquisition stability, and their variability across eleven centres. In addition a subset of the NEMA NU-2001 standards measurements was performed. We found (i) significant variability in the DOI decoding results between centres, (ii) a trend toward an increasing number of detected true coincident events as a function of elapsed time from scanner calibration likely due to a shifting energy spectrum, (iii) a count-rate dependent layer identification, (iv) scatter fraction ranging from ∼ 42% to 54% where the variability was partly related to the shifting of the energy spectrum, (v) sensitivity ranging from ∼ 5.5% to 6.5% across centres, (vi) resolution of ∼ (2.5mm) 3 , fairly consistent across centres, (vii) image quality which is very comparable to other scanners.