Job Monitoring in an Interactive Grid Analysis Environment

The grid is emerging as a great computational resource but its dynamic behavior makes the Grid environment unpredictable. Systems and networks can fail, and the introduction of more users can result in resource starvation. Once a job has been submitted for execution on the grid, monitoring becomes essential for a user to see that the job is completed in an efficient way, and to detect any problems that occur while the job is running. In current environments once a user submits a job he loses direct control over the job and the system behaves like a batch system: the user submits the job and later gets a result back. The only information a user can obtain about a job is whether it is scheduled, running, cancelled or finished. Today users are becoming increasingly interested in such analysis grid environments in which they can check the progress of the job, obtain intermediate results, terminate the job based on the progress of job or intermediate results, steer the job to other nodes to achieve better performance and check the resources consumed by the job. In order to fulfill their requirements of interactivity a mechanism is needed that can provide the user with real time access to information about different attributes of a job. In this paper we present the design of a Job Monitoring Service, a web service that will provide interactive remote job monitoring by allowing users to access different attributes of a job once it has been submitted to the interactive Grid Analysis Environment

Linking asteroids and meteorites to the primordial planetesimal population

Meteorites provide a unique insight into early Solar System processes. However, to fully interpret this record requires that these meteorites are related back to their source asteroids and ultimately to the original planetesimal population that formed early in Solar System history. As a first step in this process an assessment has been undertaken of the likely number of distinct source asteroids sampled by meteorites and related extraterrestrial materials. The results of this survey indicate that there are between 95 and 148 parent bodies represented in our sample collections. This number has been steadily increasing as new “anomalous” meteorites are characterized. Attempts to link these parent bodies to identified asteroidal sources has so far been of limited success, due to the non-unique reflectance spectra of almost all known asteroids. Asteroid (4) Vesta and the HEDs (howardites, eucrite, diogenite) meteorites is the best example of a relatively non-disputed asteroid-meteorite linkage. As part of this study the “parent body” concept has been examined and it is found to be a widely, but loosely, used term in the literature to designate “a body that supplies meteorites to Earth.” This concept could be rendered more meaningful by discriminating between primary and secondary parent bodies. A primary parent body is the source asteroid from which the meteorite is ultimately derived, and a secondary parent body is an asteroid derived through impact or break-up of the primary body. A clear example of this usage is provided by (4) Vesta, with the main asteroid being the primary parent body and the Vestoids representing secondary parent bodies. The concept of primary vs. secondary parent bodies may have important implications for early Solar System evolution. Chondritic parent bodies are known to have accreted between 1 and 4 Myr after CAIs. This timing difference may reflect the fact that their source asteroids, particularly those of the carbonaceous chondrites, are secondary bodies, with the original CAI-bearing primary bodies destroyed during early collisional processing. The number of primary parent bodies represented by meteorites (95 to 148) appears low when compared to the estimated number of asteroids in the main belt (> 100,000 with diameters exceeding ∼2 km). A range of potential reasons may explain this apparent mismatch: i) meteorites provide an unrepresentative sampling of the main belt, ii) the belt may only contain a limited number of primary parent bodies, iii) meteorites may be preferentially derived from the ∼120 identified asteroid families, iv) loosely consolidated types are filtered by Earth’s atmosphere, v) multiple, near-identical, “clone” parent bodies may be present in the belt. At present, it is not possible to determine which of these potential mechanisms are dominant and all may be operating to a greater or lesser extent. Based on classical accretion models the meteorite record appears to be highly unrepresentative of the primordial asteroid population. In contrast, pebble accretion models suggest that these first-generation bodies may have been relatively large, in which case meteorites may provide a more unbiased record of early Solar System processes

Job Interactivity Using a Steering Service in an Interactive Grid Analysis Environment

Grid computing has been dominated by the execution of batch jobs. Interactive data analysis is a new domain in the area of grid job execution. The Grid-Enabled Analysis Environment (GAE) attempts to address this in HEP grids by the use of a Steering Service. This service will provide physicists with the continuous feedback of their jobs and will provide them with the ability to control and steer the execution of their submitted jobs. It will enable them to move their jobs to different grid nodes when desired. The Steering Service will also act autonomously to make steering decisions on behalf of the user, attempting to optimize the execution of the job. This service will also ensure the optimal consumption of the Grid user's resource quota. The Steering Service will provide a web service interface defined by standard WSDL. In this paper we have discussed how the Steering Service will facilitate interactive remote analysis of data generated in Interactive Grid Analysis Environment

Network-assemblages of mediated sex: a post human study of the digital sexual practices of men who have sex with men

This thesis explores the translation of post human ontologies into a relational epistemological approach, taking the case study of men who have sex with men’s (MSM’s) digital sexual practices. It reports the findings from a connective ethnography, utilising a mixture of digital observation and insider-ethnographic accounts, to explore the inter-relationship between media as MSM engage in digital sexual practices. The main aim driving this study was to explore how social practices – in this case MSM’s digital sexual practices – could be researched differently, and what a different perspective brings to the study of such practices, and to the practices themselves. Though the literature exploring MSM’s use of digital media to engage in sexual activities is diverse, to date it has been dominated by anthropocentric methodologies and analyses e.g. through a focus on human meaning making and representation. Taking the example of MSM’s digital sexual practices therefore provided a body of literature that formed a counterpoint from which to explore the knowledge produced by different methodologies. The choice of post humanism as a way of enacting this difference – specifically the conceptual frameworks of assemblages (Deleuze and Guattari 2000, 2005) and networks (Latour 2005), or what I term “network-assemblages” – was therefore strategic. It countered the anthropocentricism dominating the field of MSM’s digital sexuality research, and also afforded the materiality of these practices greater agency in the research process. The contribution of this thesis is twofold. Firstly, it adds methodologically to the social sciences through the application of a post human ontology/epistemology to empirical research. By mapping linkages between venues as they form a network-assemblage, and by examining a single venue within this as a relational web of concepts, words, and things, it demonstrates different ways through which post human relational ontologies can be actualised in the study of phenomenon. Secondly this thesis contributes original insight into MSM’s digital sexual practices themselves. Specifically however, it explores the influence of capitalism on emergent forms of digital sexual enunciations, taking the case study of MSM’s commercial sex activities. Furthermore, it highlights the different ways in which sexuality is actualised within digital materiality; as aesthetic values, as sets of systems, as flows of words and images, and finally as lived territories

Recent advances in x-ray cone-beam computed laminography

X-ray computed tomography is a well established volume imaging technique used routinely in medical diagnosis, industrial non-destructive testing, and a wide range of scientific fields. Traditionally, computed tomography uses scanning geometries with a single axis of rotation together with reconstruction algorithms specifically designed for this setup. Recently there has however been increasing interest in more complex scanning geometries. These include so called X-ray computed laminography systems capable of imaging specimens with large lateral dimensions, or large aspect ratios, neither of which are well suited to conventional CT scanning procedures. Developments throughout this field have thus been rapid, including the introduction of novel system trajectories, the application and refinement of various reconstruction methods, and the use of recently developed computational hardware and software techniques to accelerate reconstruction times. Here we examine the advances made in the last several years and consider their impact on the state of the art

The effects of supplementary food on the breeding performance of Eurasian reed warblers Acrocephalus scirpaceus; implications for climate change impacts

Understanding the mechanisms by which climate variation can drive population changes requires information linking climate, local conditions, trophic resources, behaviour and demography. Climate change alters the seasonal pattern of emergence and abundance of invertebrate populations, which may have important consequences for the breeding performance and population change of insectivorous birds. In this study, we examine the role of food availability in driving behavioural changes in an insectivorous migratory songbird; the Eurasian reed warbler Acrocephalus scirpaceus. We use a feeding experiment to examine the effect of increased food supply on different components of breeding behaviour and first-brood productivity, over three breeding seasons (2012–2014). Reed warblers respond to food-supplementation by advancing their laying date by up to 5.6 days. Incubation periods are shorter in supplemented groups during the warmest mean spring temperatures. Nestling growth rates are increased in nests provisioned by supplemented parents. In addition, nest predation is reduced, possibly because supplemented adults spend more time at the nest and faster nestling growth reduces the period of vulnerability of eggs and nestlings to predators (and brood parasites). The net effect of these changes is to advance the fledging completion date and to increase the overall productivity of the first brood for supplemented birds. European populations of reed warblers are currently increasing; our results suggest that advancing spring phenology, leading to increased food availability early in the breeding season, could account for this change by facilitating higher productivity. Furthermore, the earlier brood completion potentially allows multiple breeding attempts. This study identifies the likely trophic and behavioural mechanisms by which climate-driven changes in invertebrate phenology and abundance may lead to changes in breeding phenology, nest survival and net reproductive performance of insectivorous birds

Distributed Analysis and Load Balancing System for Grid Enabled Analysis on Hand-held devices using Multi-Agents Systems

Handheld devices, while growing rapidly, are inherently constrained and lack the capability of executing resource hungry applications. This paper presents the design and implementation of distributed analysis and load-balancing system for hand-held devices using multi-agents system. This system enables low resource mobile handheld devices to act as potential clients for Grid enabled applications and analysis environments. We propose a system, in which mobile agents will transport, schedule, execute and return results for heavy computational jobs submitted by handheld devices. Moreover, in this way, our system provides high throughput computing environment for hand-held devices.Comment: 4 pages, 3 figures. Proceedings of the 3rd International Conference on Grid and Cooperative Computing (GCC 2004

Heterogeneous Relational Databases for a Grid-enabled Analysis Environment

Grid based systems require a database access mechanism that can provide seamless homogeneous access to the requested data through a virtual data access system, i.e. a system which can take care of tracking the data that is stored in geographically distributed heterogeneous databases. This system should provide an integrated view of the data that is stored in the different repositories by using a virtual data access mechanism, i.e. a mechanism which can hide the heterogeneity of the backend databases from the client applications. This paper focuses on accessing data stored in disparate relational databases through a web service interface, and exploits the features of a Data Warehouse and Data Marts. We present a middleware that enables applications to access data stored in geographically distributed relational databases without being aware of their physical locations and underlying schema. A web service interface is provided to enable applications to access this middleware in a language and platform independent way. A prototype implementation was created based on Clarens [4], Unity [7] and POOL [8]. This ability to access the data stored in the distributed relational databases transparently is likely to be a very powerful one for Grid users, especially the scientific community wishing to collate and analyze data distributed over the Grid