402 research outputs found
sj-pdf-1-std-10.1177_0956462420983783 – Supplemental Material for Comparison of cohort characteristics in Central Africa International Epidemiology Databases to Evaluate AIDS and Demographic Health Surveys: Rwanda and Burundi
No full textSupplemental Material, sj-pdf-1-std-10.1177_0956462420983783 for Comparison of cohort characteristics in Central Africa International Epidemiology Databases to Evaluate AIDS and Demographic Health Surveys: Rwanda and Burundi by Anna Mageras, Ellen Brazier, Théodore Niyongabo, Gad Murenzi, Jean D’Amour Sinayobye, Adebola A Adedimeji, Christella Twizere, Elizabeth A Kelvin, Kathryn Anastos, Denis Nash and Heidi E Jones in International Journal of STD & AIDS</p
Another Part of the Forest
No full textFred Vacha, John Babington, William Paterson, Harriet Brazier, Edward Gary, Barbara Stanton, Mary Ellen Verheyden, Ella Apple, William Swetland, Jeanne Driver and Rolf Engelhard
Multi-level Reconfigurable Self-organization in Overlay Services
No full textLarge-scale decentralized systems organized in overlay networks are complex to manage. Such systems integrate organizational complexity in the application-level resulting in low abstraction and modularity in their services. This thesis introduces a multi-level conceptual architecture for overlay services. An overlay service is a large-scale decentralized system organized in overlay networks that provides generic application capabilities. Two overlay services introduced in this thesis provide a proof-of-concept for the higher abstraction and modularity that can be achieved with this architecture. The first overlay service builds and maintains overlay networks that are self-organized in different tree topologies according to different application criteria. The second overlay service performs a function-indepencent and routing-independent decentralized aggregation of values that are distributed in a network and continuously changing. Experimental evaluation studies the performance trade-offs imposed by this generic design. This thesis studies overlay services in the application domain of the Smart Power Grid. More specifically, overlay services are used in demand-side energy management to perform (i) load-shifting and (ii) demand-adjustment in a fully decentralized fashion. The evaluation of this approach is grounded in the current reality and practice of the Smart Power Grid.Multi Actor SystemsTechnology, Policy and Managemen
Negotiation and Monitoring in Open Environments
No full textLarge scale, distributed, digital environments offer vast potential. Within these environments, software systems will provide unprecedented support for daily life. Offering access to vast amounts of knowledge and resources, these systems will enable wider participation of society, at large. An example is the Smart Energy Grid that increases sustainability and decreases reliance on fossil fuels. Such systems require technology that is capable of negotiating Service Level Agreements (SLAs) between consumers and providers. Multi Agent Systems (MAS) is one such technology that offers a straightforward analog for complex systems of autonomous parties. MAS is based on the notion of autonomous agents that represent human actors (i.e. owners) and are capable of negotiating SLAs and coordinating processes with other agents. They know their owner’s preferences and needs. They are capable of negotiating price, Quality of Service (QoS) characteristics and penalties. They also monitor provisioning of services to detect and penalize service violations. This dissertation presents a MAS framework for automated negotiation and monitoring of SLAs in open environments. In this context, an open environment is a large-scale, distributed environment that is also dynamic and untrusted. This framework enables secure discovery, negotiation and access to distributed resources. Through a process of exchanging messages (e.g. offers, counter-offers), agents together search for a mutually acceptable agreement (e.g. service, price, quality). A negotiation protocol defines the negotiation objects (i.e. offers), language and rules governing interaction. This dissertation presents the WS-Agreement Negotiation protocol with extensions for open environments. This protocol is experimentally validated in the AgentScape middleware. Open environments also present challenges regarding security, trust and privacy. No single authority has complete control over an open environment and no single authority governs the actions of all participants (i.e. agents). Therefore, additional mechanisms are required to ensure security, privacy and promote trust between participants. Automated monitoring mechanisms using a Trusted Third Party (TTP) address issues of security and thus support negotiation in open environments. This dissertation presents a self-adaptive monitoring approach that (1) offers monitoring assurance that agreements are honored, (2) builds a secure audit log of agreement compliance, (3) performs measurements while safeguarding privacy of (sensitive) data, (4) dynamically reacts to changes in risk and (5) enables trust-building between consumers and providers. This monitoring approach is experimentally validated in the AgentScape middleware. Automation of complex tasks, such as negotiation, can increase efficiency. To illustrate these benefits, the framework is applied to two complex systems, including the Smart Energy Grid. In this case, the looming complexity crisis of intermittent generation, real-time pricing and consumer demand shifting requires immediate attention. This domain presents not only technical (e.g. smart-meters) but also social challenges (e.g. user acceptance). The MAS automation framework presented in this dissertation addresses technical challenges by reducing manual labor and increasing efficiency. Automation even enables higher utilization of green resources and reduction of waste (e.g. produced, but unconsumed energy). Transparent, trusted monitoring mechanisms address social challenges by ensuring privacy of (sensitive) data and encouraging user acceptance. Software systems, such as those presented in this dissertation, enable wider participation of society, at large, and offer vast potential.Multi Actor SystemsTechnology, Policy and Managemen
Business Process Quality Computation: Computing Non-Functional Requirements to Improve Business Processes
No full textBusiness process modelling is an important part of system design. When designing or redesigning a business process, stakeholders specify, negotiate, and agree on business requirements to be satisfied, including non-functional requirements that concern the quality of the business process. This thesis addresses the question of how to specify and compute the quality of a business process, given the model that stakeholders use. The motivation for this thesis is the increasing importance of the quality of business processes. Knowing the quality of specific business processes enables stakeholders to judge if these processes need improvement. Knowing the quality of the constructs of those processes (viz., events, inputs, activities, and outputs) and the way they are structured enables a more detailed analysis of their shortcomings and provides a basis for the design of improvements. The research challenge of this thesis is grounded in the assumption that: “Organisations need an appropriate means to effectively compute achievement of their goals and objectives by their business processes.” Given this challenge, the main research question on which this thesis focuses is: “Can the quality of a business process be computed quantitatively at different levels of granularity?” The research objective is: “To develop frameworks, factors, and metrics for computing non-functional requirements (quality) of business processes quantitatively at different levels of granularity.” The outcomes of this thesis are: 1) BPIMM, a language-independent business process integrating meta-model, based on the concepts of seven mainstream business process modelling languages: BPMN, EPC, RAD, UML AD, SADT, IDEF0, and IDEF3. 2) BPC-QC (Business Process Concept - Quality Computation), an approach to quality computation at the lowest level of granularity of a business process. The approach consists of: i. BPC-QEF (Business Process Concept - Quality Evaluation Framework), a language-independent generic framework and algorithm to compute the quality of the constructs of a business process: event, input, activity, and output. ii. A set of business process quality dimensions and factors. The following quality dimensions are distinguished: performance, efficiency, reliability, recoverability, permissibility, and availability. Each dimension categorises different quality aspects in terms of factors. A non-exhaustive set of sixteen quantitative factors is provided. iii. Quality metrics for each of the quality factors, to facilitate a quantitative computation of the quality of a specific construct of a business process. 3) BP-QC (Business Process - Quality Computation), an approach to compute the quality at the highest level of granularity of a business process. The approach consists of: i. BP-CQCF (Business Process - Compositional Quality Computation Framework), a language-independent generic framework and algorithm to compute the quality of a business process as a whole, given the quality of its constructs. ii. A set of generic business process modelling patterns to decompose a business process into more succinct parts, namely: sequential, parallel with synchronisation, exclusive, inclusive, simple loop, and complex loop. iii. A set of over one hundred computational formulae. For each combination of modelling pattern and a quality factor, there is a formula to compute the quality. 4) AAV (Approach to Application and Validation), an evaluation plan to evaluate BPIMM, BPC-QC and BP-QC in practice, together with expert stakeholders. The plan consists of the units of measure, a measurement model, and a case study procedure. To evaluate the applicability of the contributions of this thesis to real world business needs, four case studies have been conducted in different environments: a Dutch educational institution, a global financial institution, an international financial service provider, and a Dutch research project on crisis management. Each of these case studies concerns a different, single business process. This thesis shows that: 1) A quality computation approach can be adopted independent of a business process modelling language. 2) Quantitative quality factors can be introduced specifically for the constructs of a business process. 3) Quantitative metrics and computational formulae can be developed for specific quality factors, allowing the computation of different aspects of the quality of a business process quantitatively at different levels of granularity. 4) An evaluation plan can be developed to evaluate the applicability of the contributions of this thesis (viz., BPIMM, BPC-QC, and BP-QC). The contributions of this thesis are designed to be beneficial to the areas of business and management, requirements engineering, software engineering, and business process modelling. In the areas of requirements engineering and software engineering, these contributions are intended to help practitioners to consider non-functional requirements at the earliest stage. In the area of business process modelling, information systems, service computing, and cloud computing, the contributions can be used for quality-driven modelling, design, and redesign. To conclude, knowing the quality value of a business process at different levels of granularity provides a basis for its improvement.Multi Actor SystemsTechnology, Policy and Managemen
The making of Gertrude Stein: reading, writing, and Radcliffe
No full textThis dissertation proposes three interwoven arguments concerning Gertrude Stein’s undergraduate education at Radcliffe College in the late 19th century. First, that Stein’s Sophomore writing course in 1894-1895 – English 22, Daily Themes – played a larger role
in the course of her writing life than has been understood in the fields of Modernism and
American literature. Second, that the first women of Radcliffe College, and before Radcliffe’s founding, of the Harvard Annex, were more integral to late 19th century growth in English and Composition at Harvard College than has been understood in the fields of
Rhetoric and Composition. Finally, that we cannot understand the expansion of Harvard College to Harvard University, the implementation of the elective system, or the founding of Radcliffe without integrating the various roles of Special Students – of which Gertrude Stein was one – in the broadening mission of the Cambridge institution. Following these threads, and focusing on Stein as an emblematic – though
idiosyncratic – student, I provide a history of Harvard-Radcliffe during the 1870s-1890s, a period of unprecedented change, the decades before and during Stein’s attendance from 1893-1898. I examine the role of female students in the origins of English Composition, a history which has previously focused heavily on male education as it emanated from Harvard and reverberated throughout higher education into the 20th century. I focus on Stein as a student of the pedagogy of Daily Themes practiced by Barrett Wendell. In providing these institutional, historical, and pedagogical contexts, I aim to connect Stein,
the student writer, to the adult innovator, to form a trajectory from her English 22 course into her adult writing life. My goal is for us to understand “The Making of Gertrude Stein” as a consequence, in part, of her reading and writing at Radcliffe. This is an educational
history of one of America’s great modernist writers embedded in the institutional history of her alma mater.
In order to help further research on Gertrude Stein’s undergraduate writing, my dissertation includes in its appendices the digitized images of Stein’s Daily Themes for English 22 at Radcliffe and my annotated transcription of the Themes including professorial comments.Ph.D.Includes abstractVitaIncludes bibliographical referencesby Michelle J. Brazie
The SF-36: a simple, effective measure of mobility disability for epidemiological studies
No full textBackgroundMobility disability is a major problem in older people. Numerous scales exist for the measurement of disability but often these do not permit comparisons between study groups. The physical functioning (PF) domain of the established and widely used Short Form-36 (SF-36) questionnaire asks about limitations on ten mobility activities.ObjectivesTo describe prevalence of mobility disability in an elderly population, investigate the validity of the SF-36 PF score as a measure of mobility disability, and to establish age and sex specific norms for the PF score.MethodsWe explored relationships between the SF-36 PF score and objectively measured physical performance variables among 349 men and 280 women, 59-72 years of age, who participated in the Hertfordshire Cohort Study (HCS). Normative data were derived from the Health Survey for England (HSE) 1996.Results32% of men and 46% of women had at least some limitation in PF scale items. Poor SF-36 PF scores (lowest fifth of the gender-specific distribution) were related to: lower grip strength; longer timed-up-and-go, 3m walk, and chair rises test times in men and women; and lower quadriceps peak torque in women but not men. HSE normative data showed that median PF scores declined with increasing age in men and women.ConclusionOur results are consistent with the SF-36 PF score being a valid measure of mobility disability in epidemiological studies. This approach might be a first step towards enabling simple comparisons of prevalence of mobility disability between different studies of older people. The SF-36 PF score could usefully complement existing detailed schemes for classification of disability and it now requires validation against them
Towards Use-Case Driven Self-Management of Distributed Systems
No full textThe growing complexity of distributed systems makes their management a challenge. Manual management of these systems is costly and time consuming. Autonomic computing has been proposed to reduce the cost of maintaining complex systems by developing computer systems capable of self-management. A self-managed system consists of multiple autonomic managers and multiple management units. This thesis explores the potentials of autonomic computing for management of existing distributed systems. The management units in the autonomic approach proposed in this thesis are system behaviours. For a self-managed system to be able to recognise and solve a large portion of its malfunctions on its own, it needs to have knowledge about its own behaviours. As this knowledge is mainly specified in use-case notations during the software design and development phase, this thesis proposes to reuse the use-case notations for self-management purposes. Use-cases are usually expressed in a semi-formal way. They must be expressed in a formal language to be processable and understandable by software modules (autonomic managers). For this purpose, a management model (the way an autonomic manager manages a use-case realisation and the way multiple autonomic managers cooperate with each other) and a system model (the way a managed system provides its functionalities and description of the internal structure of a managed system) are proposed and constructed. All knowledge included in these generic models is represented in formal knowledge representation languages (the Semantic Web languages OWL and SWRL). A self-management framework based on the management and system models is designed and implemented. The framework provides an execution environment for autonomic managers to manage behaviours of an existing distributed system. Furthermore, the framework can be used to generate code for the autonomic managers, based on declarative behaviour descriptions.Systems EngineeringTechnology, Policy and Managemen
A study of social work services rendered to negroes by the Catholic church in the District of Columbia in the light of what is being done throughout the country
No full textFostering Social Interaction in Playful Cities
No full textThis paper describes different types of activities/challenges designed for social interaction, while discussing the performance of such challenges using the mobile digital game “Secrets of the South” (http://secretsofthesouth.tbm.tudelft.nl/, Secrets of the South). The game was played as part of a scientific meeting, with participants from 25 to 62 years of age and a varying degree of cultural differences. The presentation and discussion of the results of the gameplay provide insights on the appropriateness of the different challenges for social interaction in a playful city. Directions for future work for such challenge designs are presented.Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.System Engineerin
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