1,720,995 research outputs found
A Knowledge Based Collaborative Design Environment
No full textIn this paper, we propose an agent based collaborative design environment in which human designers and software agents interact with each other, exchange design information and keep track of state information to assist with collaborative design. First of all, it presents a hierarchical multi-agent system architecture for integrating design and engineering tools, software agents and human specialists in an open environment. The hierarchical multi-agent system architecture offers a promising framework with their novel approaches for dynamically creating and managing design tasks in widely distributed and ever-changing design environments. Secondly, it introduces a collaborative design process model and the dynamic management approach for collaborative design process. Then, the structure of a design agent, its static knowledge and dynamic knowledge are introduced respectively. The knowledge based design approach provides a foundation for supporting reusable design activities. Finally, the cooperative design process is illustrated by a bicycle design example
Managing Violations in Service Level Agreements
No full textA Service Level Agreement (SLA) represents an agreement between a service user and a provider in the context of a particular service provision. SLAs contain Quality of Service properties that must be maintained by a provider. These are generally defined as a set of Service Level Objectives (SLOs). These properties need to be measurable and must be monitored during the provision of the service that has been agreed in the SLA. The SLA must also contain a set of penalty clauses specifying what happens when service providers fail to deliver the preagreed quality. Although significant work exists on how SLOs may be specified and monitored, not much work has focused on actually identifying how SLOs may be impacted by the choice of specific penalty clauses. The participation of a trusted mediator may be necessary to resolve conflicts between involved parties. The main focus of the paper is on identifying particular penalty clauses that can be associated with an SLA
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Orchestration of resources in distributed, heterogeneous grid environments using dynamic service level agreements
Full text linkDie Akzeptanz des Internets und der zunehmende Ausbau von Netzwerkkapazitäten ermöglichen bereits heute einen effizienten und zuverlässigen Austausch riesiger Datenmengen zwischen verschiedenen Rechensystemen weltweit. Hieraus resultieren neue Paradigmen bei der Bereit-stellung und Nutzung verteilter IT-Ressourcen wie zum Beispiel das Grid-Computing. Im Grid-Computing werden Rechenressourcen verschiedener Institutionen bzw. Organisationen koordiniert zur Lösung wissenschaftlicher und wirtschaftlicher Problemstellungen genutzt. Neben Rechenressourcen werden dabei auch Daten, Datenspeicher oder Software bereitgestellt. Die Qualität mit der diese Ressourcen bereitgestellt werden gewinnt dabei zunehmend an Bedeutung. Qualitätseigenschaften sind zum Beispiel die minimale Verfügbarkeit von Rechenressourcen, die maximale Zugriffszeit eines Datenspeichers oder die maximale Antwortzeit einer web-basierten Anwendung. Für Ressourcenanbieter bedeutet dies dass spezifische Prozesse implementiert werden müssen um qualitativ hochwertige IT-Dienste bereitzustellen. Zudem können Dienste mit unterschiedlichen Dienstqualitäten bereitgestellt werden, wobei Dienste mit geringerer Qualität preiswerter angeboten werden als solche mit hoher Qualität. Anwender hingegen können den für sie passenden Dienst hinsichtlich ihrer Anforderungen und ihres Budgets auswählen.
Service Level Agreements (SLAs) sind ein akzeptierter Ansatz um Verträge über IT-Dienste und Dienstqualitäten zu realisieren. SLAs beschreiben sowohl die funktionalen als auch die nicht-funktionalen Anforderungen von IT-Diensten als auch Vergütung und Strafen für Erfüllung bzw. Nichterfüllung der definierten Anforderungen. Diese Arbeit behandelt Methoden zur Verhandlung und Verwaltung von dynamischen SLAs in verteilten Systemen auf Basis des WS-Agreement Standards. Im Fokus steht hierbei die Deklaration von SLAs, deren automatisierte Verhandlung und Erstellung, das Monitoring von SLA Garantien, sowie die Verwendung von SLAs zur koordinierten Nutzung von IT-Ressourcen. Zu diesem Zweck wurde aufbauend auf die WS-Agreement Spezifikation ein Protokoll zur dynamischen Verhandlung bzw. Neuverhandlung von SLAs entwickelt. Dies beinhaltet die Definition eines Verhandlungsmodells zum Austausch von Angeboten zwischen den Verhandlungspartnern. Die anschließende Erstellung der SLAs basiert auf dem WS-Agreement Standard stellt einen automatisierter Prozess dar. Da es sich bei SLAs um elektronische Verträge handelt wurden Mechanismen zur Validierung von SLA Angeboten entwickelt und im Detail vorgestellt. Darüber hinaus werden Methoden zur automatisierten Evaluation von SLA Garantien beschrieben. Abschließend wird die Architektur und Implementierung eines Orchestrierungsdienstes zur Co-Allokation beliebiger Ressource wie z.B. Rechen- und Netzwerkressourcen vorgestellt. Die Ressourcenorchestrierung wurde hierbei mittels SLAs realisiert.In recent decades the acceptance of the internet and the increase of network capacity have resulted in a situation in which it is now possible to transfer huge amounts of data efficiently and reliably between different computing systems worldwide. This enables new paradigms in provision and use of distributed IT resources. Grid computing is such a well-known paradigm where computing resources owned by various institutions and organizations are used in a coordinated way in order to solve scientific and economic problems. Besides computing resources also data, storage or software resources are provided. Today it becomes more and more important with which quality the different resources are provided. This may be, for example, the minimal availability of computing resources, the maximum access time of a data storage or the maximum response time of a web-based application. Offering resources with a defined quality means for resource providers that they need to implement specific processes to assert the quality of the provisioning process. On the other hand, resource providers can offer their services at different quality levels. Services with a lower quality can be offered cheaper than those with a higher quality. Service consumers can therefore select the service with the appropriate service level in terms of their requirements and budget. This provides both parties, service provider and consumer, with more flexibility during the service provisioning process.
Service level agreements (SLAs) are an accepted approach to realize contracts for IT services and service qualities. They describe the functional and the non-functional requirements of IT services. Additionally, they define compensation and penalties for delivering services with the defined requirements respectively for failing to meet these quality criteria. This thesis examines methods for negotiation and management of SLAs in distributed systems based on the WS-Agreement standard. The focus is on methods for SLA declaration, automated SLA negotiation and creation processes, monitoring of SLA guarantees, and the application of SLAs for coordinated IT resource provisioning. Therefore, a protocol for dynamic negotiation or renegotiation of SLAs is developed as an extension to the WS-Agreement specification. This includes the definition of a negotiation model for the exchange of offers between the negotiating partners. The subsequent SLA creation process is an automated process in distributed systems. Since SLAs are a kind of electronic contracts a mechanism for validating the integrity of SLA offers was developed and is presented in detail. In addition, automatic methods for SLA guarantee evaluation are described. Finally, an orchestration service for co-allocating arbitrary resources such as computing and network resources is presented. The resource orchestration process has been realized using SLAs. The architecture of this service is evaluated and based on the evaluation result an advanced orchestration service architecture is conceived
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
Benefits and implications of Augmented Reality Positioning Systems for Offshore Topside Installations
No full textThe oil and gas industry is seeking to improve safety on its current operations procedures (Choudarki, 2012). From all oil and gas operations, Topside Installation Processes (TIP) are the only offshore activity that counters one of the golden safety rules, “do not stand or walk under suspended loads” (Peuscher & Groeneweg, 2012). As a consequence, marine companies are seeking to improve these processes through different technological solutions (Heerema Marine Contractors, 2014). TIP generally consist on the lifting of a heavy module, topside, and its placement on a fixed structure on the sea, jacket (Hee et al., 2007). Traditional positioning tools such as bumpers and guides are not suitable for these type of processes given the heaviness and big dimensions of topsides (Heerema Marine Contractors, 2017). As a consequence, part of the vessel crew is located on the jacket, under the suspended topside, to guide the positioning processes (Breidablikk, 2010). TIP imply the presence of crew members under a suspended load, which is contrary to oil and gas companies’ safety policy. The offshore industry is currently investigating ways to circumvent having personnel on the jacket during topside installations (Heerema Marine Contractors, 2014). The implementation of a camera-based augmented reality positioning tracking system could fulfil the current safety requirements. The use of augmented reality as a positioning tool is a completely new technology that has never been used before in this domain. This research explores the potential expected benefits of the use of an Augmented Reality Positioning System (ARPS) during Offshore Topside Installation Processes (OTIP). This research also investigates the system’s usefulness and the users’ system perception on its usability in OTIP. Moreover, it explores the implications and factors that should be considered in order to successfully implement the ARPS in this type of processes. The research is based on a case that relates to the first augmented reality positioning system for topside installation processes, that is being developed by TWNKLS and Heerema Marine Contractors. The research methodology is based on data collected from different experiments and interview processes. The conclusions include discussion about the benefits, usability and implications of ARPS in OTIP, and recommendations for the ARPS developing companies and for future research. Key words: Augmented Reality, Innovation, Topside Installation, Safety, Offshore, Positioning Processes
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