11 research outputs found

    A Novel Mechanism for Gridification of Compiled Java Applications

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    Exploiting Grids intuitively requires developers to alter their applications, which calls for expertise on Grid programming. Gridification tools address this problem by semi-automatically making user applications to be Grid-aware. However, most of these tools produce monolithic Grid applications in which common tuning mechanisms (e.g. parallelism) are not applicable, and do not reuse existing Grid middleware services. We propose BYG (BYtecode Gridifier), a gridification tool that relies on novel bytecode rewriting techniques to parallelize and easily execute existing applications via Grid middlewares. Experiments performed by using several computing intensive applications on a cluster and a simulated wide-area Grid suggest that our techniques are effective while staying competitive compared to programmatically using such services for gridifying applications

    EasyFJP: Providing Hybrid Parallelism as a Concern for Divide and Conquer Java Applications

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    Because of the increasing availability of multi-core machines, clus- ters, Grids, and combinations of these there is now plenty of computational power,but today's programmers are not fully prepared to exploit parallelism. In particular, Java has helped in handling the heterogeneity of such environments. However, there is a lot of ground to cover regarding facilities to easily and elegantly parallelizing applications. One path to this end seems to be the synthesis of semi- automatic parallelism and Parallelism as a Concern (PaaC). The former allows users to be mostly unaware of parallel exploitation problems and at the same time manually optimize parallelized applications whenever necessary, while the latter allows applications to be separated from parallel-related code. In this paper, we present EasyFJP, an approach that implicitly exploits parallelism in Java applications based on the concept of fork-join synchronization pattern, a simple but effective abstraction for creating and coordinating parallel tasks. In addition, EasyFJP lets users to explicitly optimize applications through policies, or user-provided rules to dynamically regulate task granularity. Finally, EasyFJP relies on PaaC by means of source code generation techniques to wire applications and parallel-specific code together. Experiments with real-world applications on an emulated Grid and a cluster evidence that EasyFJP delivers competitive performance compared to state-of-the-art Java parallel programming tools.Fil: Mateos Diaz, Cristian Maximiliano. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico - CONICET - Tandil. Instituto Superior de Ingenieria del Software; Argentina;Fil: Zunino Suarez, Alejandro Octavio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico - CONICET - Tandil. Instituto Superior de Ingenieria del Software; Argentina;Fil: Hirsch Jofré, Matías Eberardo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico - CONICET - Tandil. Instituto Superior de Ingenieria del Software; Argentina

    A semi-automatic parallelization tool for Java based on fork-join synchronization patterns

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    Because of the increasing availability of multi-core machines, clusters, Grids, and combinations of these environments, there is now plenty of computational power available for executing compute intensive applications. However, because of the overwhelming and rapid advances in distributed and parallel hardware and environments, today?s programmers are not fully prepared to exploit distribution and parallelism. In this sense, the Java language has helped in handling the heterogeneity of such environments, but there is a lack of facilities and tools to easily distributing and parallelizing applications. One solution to mitigate this problem and make some progress towards producing general tools seems to be the synthesis of semi-automatic parallelism and Parallelism as a Concern (PaaC), which allows parallelizing applications along with as little modifications on sequential codes as possible. In this paper, we discuss a new approach that aims at overcoming the drawbacks of current Java-based parallel and distributed development tools, which precisely exploit these new conceptsFil: Hirsch, Matias. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico - CONICET - Tandil. Instituto Superior de Ingenieria del Software; Argentina;Fil: Zunino, Alejandro. Consejo Nacional de Invest.cientif.y Tecnicas. Ctro Cientifico Tecnologico Conicet - Tandil. Instituto Superior de Ingenieria del Software;Fil: Mateos Diaz, Cristian Maximiliano. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico - CONICET - Tandil. Instituto Superior de Ingenieria del Software

    A semi-automatic parallelization tool for Java based on fork-join synchronization patterns

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    Because of the increasing availability of multi-core machines, clusters, Grids, and combinations of these environments, there is now plenty of computational power available for executing compute intensive applications. However, because of the overwhelming and rapid advances in distributed and parallel hardware and environments, today’s programmers are not fully prepared to exploit distribution and parallelism. In this sense, the Java language has helped in handling the heterogeneity of such environments, but there is a lack of facilities and tools to easily distributing and parallelizing applications. One solution to mitigate this problem and make some progress towards producing general tools seems to be the synthesis of semi-automatic parallelism and Parallelism as a Concern (PaaC), which allows parallelizing applications along with as little modifications on sequential codes as possible. In this paper, we discuss a new approach that aims at overcoming the drawbacks of current Java-based parallel and distributed development tools, which precisely exploit these new concepts.Sociedad Argentina de Informática e Investigación Operativ

    An analysis of frequent ways of making undiscoverable Web Service descriptions

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    The ever increasing number of publicly available Web Services makes standardcompliant service registries one of the essential tools to service-oriented application developers. Previous works have shown that the descriptiveness of published service descriptions is important from the point of view of the algorithms that support service discovery using this kind of registries as well as human developers, who have the final word on which discovered service is more appropriate. This paper presents a catalog of frequent bad practices in the creation of Web Service descriptions that attempt against their chances of being discovered, along with novel practical solutions to them.Additionally, the paper presents empirical evaluations that corroborated the benefits of the proposed solutions. These anti-patterns will help service publishers avoid common discoverability problems and improve existing service descriptions.Sociedad Argentina de Informática e Investigación Operativ

    MODELLING SUBGRADE FLUIDISATION UNDER RAIL TRACKS BASED ON LBM-DEM COUPLING

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    Railways play an essential role in transportation and economy in Australia; however, due to the increasing demand for rail transport in recent years, railway infrastructure inevitably faces extensive degradation. One of the severe issues causing the degradation of rail tracks is mud pumping, where the fines intrude into the ballast layer to form slurry state under wet condition. Mud pumping is a complex process involving different mechanisms, including subgrade fluidisation, internal erosion, filtration and upward migrations of fines. This thesis focuses on the fluidisation of subgrade soil under increasing excess pore water pressure, which results in fines penetrating overlying ballast. Traditional methods such as experimental and analytical approaches can capture the macro-behaviours of soil such as soil settlement and hydraulic conductivity under increasing excess pore pressure; however, they have many limitations when microscopic and localised behaviour must be addressed. Therefore, this study proposed a numerical method that couples the Lattice Boltzmann Method (LBM) with the Discrete Element Method (DEM) to capture soil behaviours under increasing hydraulic gradient at both macro and micro scales. While particle behaviour is modelled using the DEM, the fluid properties can be depicted in greater detail based on the LBM. The numerical results are validated with experiments on a selected subgrade soil. The results show that the numerical method can reasonably predict the hydraulic and soil fluidisation aspects concerning the experimental data. Microscopic properties such as the localised fluid velocity through the porous spaces of the soil are also captured well by the proposed fluid-particle coupling approach. Also, the gas fluidisation is carried out in this study using LBM-DEM coupling to further validate the numerical method. The results are compared with the conventional CFD (Computational Fluid Dynamics) - DEM coupling and show a good agreement between LBM-DEM and CFD-DEM coupling

    Security for Mobile Grid Systems

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    Grid computing technology is used as inexpensive systems to gather and utilize computational capability. This technology enhances applications services by arranging machines and distributed resources in a single huge computational entity. A Grid is a system that has the ability to organize resources which are not under the subject of centralized domain, utilize protocols and interfaces, and supply high quality of service. The Grid should have the ability to enhance not only the systems performance and job throughput of the applications participated but also increase the utilization scale of resources by employing effective resource management methods to the huge amount of its resources. Grid mobility appears as a technology to facilitate the accomplishment of requirements for Grid jobs as well as Grid users. This idea depends on migrating or relocating jobs, data and application software among Grid nodes. However, making use of mobility technology leads to data confidentiality problems within the Grid. Data confidentiality is the protection of data from intruders’ attacks. The data confidentiality can be addressed by limiting the mobility to trusted parts of the Grid, but this solution leads to the notion of Virtual Organizations (VOs). Also as a result of mobility technology the need for a tool to organize and enforce policies while applying the mobility has been increased. To date, not enough attention has been paid to policies that deal with data movements within the Grid. Most existing Grid systems have support only limited types of policies (e.g. CPU resources). A few designs consider enforcing data policies in their architecture. Therefore, we propose a policy-managed Grid environment that addresses these issues (user-submitted policy, data policy, and multiple VOs). In this research, a new policy management tool has been introduced to solve the mobility limitation and data confidentiality especially in the case of mobile sharing and data movements within the Grid. We present a dynamic and heterogeneous policy management framework that can give a clear policy definition about the ability to move jobs, data and application software from nodes to nodes during jobs’ execution in the Grid environment. This framework supports a multi-organization environment with different domains, supports the external Grid user preferences along with enforces policies for data movements and the mobility feature within different domains. The results of our research have been evaluated using Jade simulator, which is a software framework fully implemented in Java language and allows agents to execute tasks defined according to the agent policy. The simulation results have verified that the research aims enhance the security and performance in the Grid environments. They also show enhanced control over data and services distribution and usage and present practical evidence in the form of scenario test-bed data as to the effectiveness of our architecture

    The Impact of Rolling Dynamic Compaction

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    Rolling dynamic compaction (RDC) consists of a non-circular module of 3, 4 or 5 sides, that rotates as it is towed, causing it to fall to the ground and compact it dynamically. There is currently little guidance available for geotechnical practitioners regarding the depths of improvement that are possible in varying soil conditions. Current practice dictates that practitioners rely on personal experiences or available published project case studies that are limited in scope and applicability as they are typically aimed at achieving a project specification. There is a reluctance to adopt RDC as a ground improvement technique as there is uncertainty regarding its limitations and capabilities. The underlying objective of this research is to quantify the ground response of the 8-tonne 4-sided impact roller. This research has used full-scale field trials and bespoke instrumentation to capture the ground response due to dynamic loading in homogeneous soil conditions. It was found that towing speed quantifiably influenced the energy imparted into the ground, with towing speeds of 10-12 km/h found to be optimal. Targeted full-scale field trials were undertaken to quantify the depth of improvement that can be achieved using RDC. Field results were compared to a number of published case studies that have used the 8-tonne 4-sided roller. Significantly, separate equations have been developed to allow practitioners to predict the depths that can be improved for the two major applications of RDC: improving ground in situ and compacting soil in thick layers. Finally, the in-ground response of RDC was measured using buried earth pressure cells (EPCs) and accelerometers. Force was determined from the measured change in stress recorded by EPCs whereas displacement was inferred from the double integration of acceleration-time data to give real-time load-displacement behaviour resulting from a single impact. The energy delivered to the soil by RDC is quantified in terms of the work done, defined as the area under the force versus displacement curve. Quantifying the energy imparted into the ground in terms of the work done is a key difference from past studies. Previous estimates of the energy delivered by impact roller at the ground surface has traditionally been predicted based on either gravitational potential energy (12 kJ) or kinetic energy (30 kJ to 54 kJ for typical towing speeds of 9 to 12 km/h). The two different values have caused confusion amongst practitioners. This research has determined that the maximum energy per impact that the 8-tonne 4-sided impact roller is capable of imparting to the ground is between 22 kJ to 30 kJ for typical towing speeds of 9 to 12 km/h. Quantifying the effectiveness of the 8-tonne 4-sided impact roller in terms of towing speed, depth of influence, and soil response measured via real-time measurements will lead to a greater understanding of the practical applications and limitations of RDC. Significantly, more accurate assessments of RDC will reduce design conservatism and construction costs, reduce instances where the predicted ground improvement does not occur and enable RDC to be used and applied with greater confidence.Thesis (Ph.D.) -- University of Adelaide, School of Civil, Environmental and Mining Engineering, 202

    Chapter 34 - Biocompatibility of nanocellulose: Emerging biomedical applications

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    Nanocellulose already proved to be a highly relevant material for biomedical applications, ensued by its outstanding mechanical properties and, more importantly, its biocompatibility. Nevertheless, despite their previous intensive research, a notable number of emerging applications are still being developed. Interestingly, this drive is not solely based on the nanocellulose features, but also heavily dependent on sustainability. The three core nanocelluloses encompass cellulose nanocrystals (CNCs), cellulose nanofibrils (CNFs), and bacterial nanocellulose (BNC). All these different types of nanocellulose display highly interesting biomedical properties per se, after modification and when used in composite formulations. Novel applications that use nanocellulose includewell-known areas, namely, wound dressings, implants, indwelling medical devices, scaffolds, and novel printed scaffolds. Their cytotoxicity and biocompatibility using recent methodologies are thoroughly analyzed to reinforce their near future applicability. By analyzing the pristine core nanocellulose, none display cytotoxicity. However, CNF has the highest potential to fail long-term biocompatibility since it tends to trigger inflammation. On the other hand, neverdried BNC displays a remarkable biocompatibility. Despite this, all nanocelluloses clearly represent a flag bearer of future superior biomaterials, being elite materials in the urgent replacement of our petrochemical dependence

    Grid-Enabling Applications with JGRIM

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    The development of massively distributed applications with enormous demands for computing power, memory, storage and bandwidth is now possible with the Grid. Despite these advances, building Grid applications is still very difficult. We present JGRIM, an approach to easily gridify Java applications by separating functional and Grid concerns in the application code, and report evaluations of its benefits with respect to related approaches. The results indicate that JGRIM simplifies the process of porting applications to the Grid, and the Grid code obtained from this process performs in a very competitive way compared to the code resulting from using similar tools.Fil: Mateos Diaz, Cristian Maximiliano. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tandil. Instituto Superior de Ingeniería del Software. Universidad Nacional del Centro de la Provincia de Buenos Aires. Instituto Superior de Ingeniería del Software; ArgentinaFil: Zunino Suarez, Alejandro Octavio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tandil. Instituto Superior de Ingeniería del Software. Universidad Nacional del Centro de la Provincia de Buenos Aires. Instituto Superior de Ingeniería del Software; ArgentinaFil: Campo, Marcelo Ricardo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tandil. Instituto Superior de Ingeniería del Software. Universidad Nacional del Centro de la Provincia de Buenos Aires. Instituto Superior de Ingeniería del Software; Argentin
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