4,537,959 research outputs found
RFID lecturer availability system
In process of learning in polytechnic, having a meeting with a lecturer was an importance thing to make sure that all the task given are clearly understand and submitted on time. As such, RFID Lecturer Availability System (L.A.S) will enable to identify the availability of the lecturer for the students. This will enable the students to get inputs if the lecturer is available or having different work to be done. The advantage of LAS is that it is easy to be used and low costs. This enable an efficient product to ensure students are aware of lecturer availability before commencing any meetings or appointment. In future, the study will focus on the evaluation of the prototype in measuring the usefulness of the application developed
Product forms for availability models
This paper shows and illustrates that product form expressions for the steady state distribution, as known for queueing networks, can also be extended to a class of availability models. This class allows breakdown and repair rates from one component to depend on the status of other components. Common resource capacities and repair priorities, for example, are included. Conditions for the models to have a product form are stated explicitly. This product form is shown to be insensitive to the distributions of the underlying random variables, i.e. to depend only on their means. Further it is briefly indicated how queueing for repair can be incorporated. Novel product form examples are presented of a simple series/parallel configuration, a fault tolerant database system and a multi-stage interconnection network
Disaster Mythology and Availability Cascades
Sociological research conducted in the aftermath of natural disasters has uncovered a number of “disaster myths” – widely shared misconceptions about typical post-disaster human behavior. This paper discusses the possibility that perpetuation of disaster mythology reflects an “availability cascade,” defined in prior scholarship as a “self-reinforcing process of collective belief formation by which an expressed perception triggers a chain reaction that gives the perception increasing plausibility through its rising availability in public discourse.” (Kuran and Sunstein 1999). Framing the spread of disaster mythology as an availability cascade suggests that certain tools may be useful in halting the myths’ continued perpetuation. These tools include changing the legal and social incentives of so-called “availability entrepreneurs” – those principally responsible for beginning and perpetuating the cascade, as well as insulating decision-makers from political pressures generated by the availability cascade. This paper evaluates the potential effectiveness of these and other solutions for countering disaster mythology. Las investigaciones sociológicas realizadas tras los desastres naturales han hecho evidentes una serie de “mitos del desastre”, conceptos erróneos ampliamente compartidos sobre el comportamiento humano típico tras un desastre. Este artículo analiza la posibilidad de que la perpetuación de los mitos del desastre refleje una “cascada de disponibilidad”, definida en estudios anteriores como un “proceso de auto-refuerzo de la formación de una creencia colectiva, a través del que una percepción expresada produce una reacción en cadena que hace que la percepción sea cada vez más verosímil, a través de una mayor presencia en el discurso público” (Kuran y Sunstein 1999). Enmarcar la propagación de los mitos del desastre como una cascada de disponibilidad sugiere que ciertas herramientas pueden ser útiles para parar la continua perpetuación de los mitos. Estas herramientas incluyen el cambio de los incentivos legales y sociales de los llamados “emprendedores de la disponibilidad”, los principales responsables del inicio y la perpetuación de la cascada, además del aislamiento de quienes toman las decisiones de las presiones políticas generadas por la cascada de disponibilidad. Este artículo evalúa la efectividad potencial de estas y otras soluciones para contrarrestar los mitos del desastre
Locality and Availability in Distributed Storage
This paper studies the problem of code symbol availability: a code symbol is
said to have -availability if it can be reconstructed from disjoint
groups of other symbols, each of size at most . For example, -replication
supports -availability as each symbol can be read from its other
(disjoint) replicas, i.e., . However, the rate of replication must vanish
like as the availability increases.
This paper shows that it is possible to construct codes that can support a
scaling number of parallel reads while keeping the rate to be an arbitrarily
high constant. It further shows that this is possible with the minimum distance
arbitrarily close to the Singleton bound. This paper also presents a bound
demonstrating a trade-off between minimum distance, availability and locality.
Our codes match the aforementioned bound and their construction relies on
combinatorial objects called resolvable designs.
From a practical standpoint, our codes seem useful for distributed storage
applications involving hot data, i.e., the information which is frequently
accessed by multiple processes in parallel.Comment: Submitted to ISIT 201
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