8 research outputs found
Differential Capacity p-Cycles
No full textSurvivability has become a central part of modern optical network design as the
hundreds of wavelengths get multiplexed on fibers carrying data at Tbps speeds in DWDM
networks. Provisioning for 100% restoration on failure using minimum amount of resources
has become an important design problem. p-Cycles have emerged as a useful fault tolerance
mechanism that operate at the speed of SONET rings, but also have low mesh-like spare
capacity requirement.
In this thesis, a modified version of p-cycle, called differential capacity p-cycle, is
proposed that improve spare capacity efficiency beyond what is provided by a set of traditional
p-cycles. Different variants of differential capacity p-cycles are proposed, analogous
to some of the traditional p-cycle variants. The designs of the various types of differential
capacity p-cycles are formulated using integer linear programs, and the spare capacity usage
of these new structures are compared with that of traditional p-cycles and their variants
Impact of Shared Electric Vehicles Availability to Provide Peak Reduction through Vehicle-to-Grid. A Case Study
No full textThis paper presents a Mix Integer Linear Programming (MILP) optimization approach to reduce peak demand and maximize revenue in a grid-connected building with a PV-equipped charging station for Shared EVs. The study investigates the impact of EV availability on the effectiveness of the system by comparing the results for different connection times of a fleet of Shared EVs, a private EV used for commuting, and a stationary battery. Results from the case study conducted in The Netherlands demonstrate that not only the duration but also the timing of EV connection significantly influence system effectiveness, emphasizing the need for accurate availability estimation. The trade-off between peak reduction and Peak-to-Average Ratio (PAR) reduction is also highlighted, underscoring the importance of considering both factors for optimizing charging station usage. These findings provide valuable insights for optimizing energy management, reducing peak loads, and increasing the utilization of renewable energy sources in the context of Shared EVs and V2G technology.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.DC systems, Energy conversion & Storag
Keys under doormats - mandating insecurity by requiring government access to all data and communications
Get PDFAbstract
Twenty years ago, law enforcement organizations lobbied to require data and communication services to engineer their products to guarantee law enforcement access to all data. After lengthy debate and vigorous predictions of enforcement channels “going dark,” these attempts to regulate the emerging Internet were abandoned. In the intervening years, innovation on the Internet flourished, and law enforcement agencies found new and more effective means of accessing vastly larger quantities of data. Today we are again hearing calls for regulation to mandate the provision of exceptional access mechanisms. In this report, a group of computer scientists and security experts, many of whom participated in a 1997 study of these same topics, has convened to explore the likely effects of imposing extraordinary access mandates.
We have found that the damage that could be caused by law enforcement exceptional access requirements would be even greater today than it would have been 20 years ago. In the wake of the growing economic and social cost of the fundamental insecurity of today’s Internet environment, any proposals that alter the security dynamics online should be approached with caution. Exceptional access would force Internet system developers to reverse “forward secrecy” design practices that seek to minimize the impact on user privacy when systems are breached.
The complexity of today’s Internet environment, with millions of apps and globally connected services, means that new law enforcement requirements are likely to introduce unanticipated, hard to detect security flaws. Beyond these and other technical vulnerabilities, the prospect of globally deployed exceptional access systems raises difficult problems about how such an environment would be governed and how to ensure that such systems would respect human rights and the rule of law
Relationship between operational flexibility and performance through bibliometric techniques
Get PDFRESUMEN: El propósito de este trabajo es realizar un análisis bibliométrico en el campo del management de operaciones,
en concreto el tema que relaciona flexibilidad operativa y la performance empresarial, en el periodo 1981-2011. En el
análisis se aplican tanto indicadores de actividad (cuantificación de autores, revistas o Ley de Lotka) como de relación
(citas por autor y revista, co-citación entre autores y análisis de co-palabras) utilizando como fuente de datos el Social
Sciences Citation Index de Web of Science. Los resultados proporcionados por los indicadores de actividad han puesto de
manifiesto que se trata de un campo de estudio relativamente reciente, en el que se verifica el cumplimiento de la ley de
Lotka, y en el que los autores y revistas más productivos no necesariamente coinciden con los más citados. El análisis de
co-citas ha identificado los autores que constituyen el marco teórico consolidado de referencia. Por último, el análisis de
co-palabras ha permitido identificar las temáticas de investigación que conforman el ámbito de estudio y su clasificación
en ampliamente desarrolladas, periféricas especializadas, periféricas poco desarrolladas y emergentes, a las que se debe
prestar atención para contribuir al desarrollo y consolidación del campo.ABSTRACT: The purpose of this paper is to present a bibliometric analysis in the field of operations management, specifically
the issue that relates operational flexibility with business performance during the period 1981-2011. The analysis applies
indicators concerning both activity (quantification of authors, journals or Lotka’s Law) and relationships (citations by author,
journal co-citation between authors and co-word analysis) using the Web of Science’s Social Sciences Citation Index as a
data source. The results provided by the activity indicators show that it is a relatively recent field of study, which verifies
compliance with the Lotka’s Law, and where the most productive authors and journals do not necessarily coincide with
the most cited ones. The co-citation analysis has identified authors of reference in the field. Finally, the co-word analysis
has allowed the identification of the research topics comprising the area of study and classified into widely developed
issues, specialized peripheral issues, peripheral underdeveloped issues, and emerging subject matters. These are the most
relevant, in that they identify important current issues that are still poorly developed
