Today’s cloud computing infrastructure requires substantial trust. Cloud users rely on both the provider’s staff and its globally distributed software/hardware platform not to expose any of their ...private data.
We introduce the notion of shielded execution, which protects the confidentiality and integrity of a program and its data from the platform on which it runs (i.e., the cloud operator’s OS, VM, and firmware). Our prototype, Haven, is the first system to achieve shielded execution of unmodified legacy applications, including SQL Server and Apache, on a commodity OS (Windows) and commodity hardware. Haven leverages the hardware protection of Intel SGX to defend against privileged code and physical attacks such as memory probes, and also addresses the dual challenges of executing unmodified legacy binaries and protecting them from a malicious host. This work motivated recent changes in the SGX specification.
Introduction to Network Simulator NS2 is a primer providing materials for NS2 beginners, whether students, professors, or researchers for understanding the architecture of Network Simulator 2 (NS2) ...and for incorporating simulation modules into NS2. The authors discuss the simulation architecture and the key components of NS2 including simulation-related objects, network objects, packet-related objects, and helper objects. The NS2 modules included within are nodes, links, SimpleLink objects, packets, agents, and applications. Further, the book covers three helper modules: timers, random number generators, and error models. Also included are chapters on summary of debugging, variable and packet tracing, result compilation, and examples for extending NS2. Two appendices provide the details of scripting language Tcl, OTcl and AWK, as well object oriented programming used extensively in NS2.
Factored operating systems (fos) Wentzlaff, David; Agarwal, Anant
Operating systems review,
04/2009, Letnik:
43, Številka:
2
Journal Article
The next decade will afford us computer chips with 100's to 1,000's of cores on a single piece of silicon. Contemporary operating systems have been designed to operate on a single core or small ...number of cores and hence are not well suited to manage and provide operating system services at such large scale. If multicore trends continue, the number of cores that an operating system will be managing will continue to double every 18 months. The traditional evolutionary approach of redesigning OS subsystems when there is insufficient parallelism will cease to work because the rate of increasing parallelism will far outpace the rate at which OS designers will be capable of redesigning subsystems. The fundamental design of operating systems and operating system data structures must be rethought to put scalability as the prime design constraint. This work begins by documenting the scalability problems of contemporary operating systems. These studies are used to motivate the design of a factored operating system (fos). fos is a new operating system targeting manycore systems with scalability as the primary design constraint, where space sharing replaces time sharing to increase scalability.We describe fos, which is built in a message passing manner, out of a collection of Internet inspired services. Each operating system service is factored into a set of communicating servers which in aggregate implement a system service. These servers are designed much in the way that distributed Internet services are designed, but instead of providing high level Internet services, these servers provide traditional kernel services and replace traditional kernel data structures in a factored, spatially distributed manner. fos replaces time sharing with space sharing. In other words, fos's servers are bound to distinct processing cores and by doing so do not fight with end user applications for implicit resources such as TLBs and caches. We describe how fos's design is well suited to attack the scalability challenge of future multicores and discuss how traditional application-operating systems interfaces can be redesigned to improve scalability.
Repasamos brevemente la historia y logros del Departamento de Física Teorica (DFT) del ICIMAF desde su fundacion en 1976. Los datos y opiniones de miembros previos y actuales del DFT fueron tomados ...de una serie de entrevistas realizadas a los participantes de la conferencia científica FT-45, realizada virtualmente en marzo de 2021, para celebrar el 45 aniversario del DFT. We briefly review the history and achievements of the Department of Theoretical Physics (DFT) of the ICIMAF since its foundation in 1976. The data and opinions of former and current members of the DFT were taken from a series of interviews made to the participants of the scientific conference FT-45, held virtually in March 2021, to celebrate the 45th anniversary of the DFT.
Resumimos brevemente los eventos clave asociados a los estudios de Física en la Universidad de Oriente, en el 50 aniversario de su primera graduación. Se discute una serie de asuntos interesantes del ...curriculum de Física en nuestra universidad, así como algunas nuevas políticas -como el actual sistema de admision, y la ensenanza al grado 12 del preuniversitario en la universidad. Finalmente, mostramos estadisticas de las graduaciones de Física. We briefly survey the key events associated to Physics studies in Oriente University in the 50th aniversary of the first graduation. A number of interesting issues of the Physics curriculum in our University are discussed; as well as some new policies -like the current admission system and the teaching of the 12th year of high school at the university. Finally, we show statistics of graduate studies in Physics.
Our aim is to reflect on orality in the processes of sacralizing communication and maintaining the batuqueira common-unity. To do this, we reviewed the literature and used empirical research data ...(Silva Neto, 2022), which was interpreted using content analysis. We inferred that, under the principles of Bara/Exu, the processes of batuqueiro communication institute symbolic content, maintain and (re)signify the sacred component, preserve tradition and enable its becoming.
