A Survey of Software-Defined Networks-on-Chip: Motivations, Challenges and Opportunities

Current computing platforms encourage the integration of thousands of processing cores, and their interconnections, into a single chip. Mobile smartphones, IoT, embedded devices, desktops, and data centers use Many-Core Systems-on-Chip (SoCs) to exploit their compute power and parallelism to meet the dynamic workload requirements. Networks-on-Chip (NoCs) lead to scalable connectivity for diverse applications with distinct traffic patterns and data dependencies. However, when the system executes various applications in traditional NoCs—optimized and fixed at synthesis time—the interconnection nonconformity with the different applications’ requirements generates limitations in the performance. In the literature, NoC designs embraced the Software-Defined Networking (SDN) strategy to evolve into an adaptable interconnection solution for future chips. However, the works surveyed implement a partial Software-Defined Network-on-Chip (SDNoC) approach, leaving aside the SDN layered architecture that brings interoperability in conventional networking. This paper explores the SDNoC literature and classifies it regarding the desired SDN features that each work presents. Then, we described the challenges and opportunities detected from the literature survey. Moreover, we explain the motivation for an SDNoC approach, and we expose both SDN and SDNoC concepts and architectures. We observe that works in the literature employed an uncomplete layered SDNoC approach. This fact creates various fertile areas in the SDNoC architecture where researchers may contribute to Many-Core SoCs designs.Las plataformas informáticas actuales fomentan la integración de miles de núcleos de procesamiento y sus interconexiones, en un solo chip. Los smartphones móviles, el IoT, los dispositivos embebidos, los ordenadores de sobremesa y los centros de datos utilizan sistemas en chip (SoC) de muchos núcleos para explotar su potencia de cálculo y paralelismo para satisfacer los requisitos de las cargas de trabajo dinámicas. Las redes en chip (NoC) conducen a una conectividad escalable para diversas aplicaciones con distintos patrones de tráfico y dependencias de datos. Sin embargo, cuando el sistema ejecuta varias aplicaciones en las NoC tradicionales -optimizadas y fijadas en el momento de síntesis, la disconformidad de la interconexión con los requisitos de las distintas aplicaciones genera limitaciones en el rendimiento. En la literatura, los diseños de NoC adoptaron la estrategia de redes definidas por software (SDN) para evolucionar hacia una solución de interconexión adaptable para los futuros chips. Sin embargo, los trabajos estudiados implementan un enfoque parcial de red definida por software en el chip (SDNoC) de SDN, dejando de lado la arquitectura en capas de SDN que aporta interoperabilidad en la red convencional. Este artículo explora la literatura sobre SDNoC y la clasifica en función de las características SDN que presenta cada trabajo. A continuación, describimos los retos y oportunidades detectados a partir del estudio de la literatura. Además, explicamos la motivación para un enfoque SDNoC, y exponemos los conceptos y arquitecturas de SDN y SDNoC. Observamos que los trabajos en la literatura emplean un enfoque SDNoC por capas no completo. Este hecho crea varias áreas fértiles en la arquitectura SDNoC en las que los investigadores pueden contribuir a los diseños de SoCs de muchos núcleos

Astrobiological field campaign to a volcanosedimentary mars analogue methane producing subsurface protected ecosystem: Imuruk Lake (Alaska)

Viking missions reported adverse conditions for life in Mars surface. High hydrogen signal obtained by Mars orbiters has increased the interest in subsurface prospection as putative protected Mars environment with life potential. Permafrost has attracted considerable interest from an astrobiological point of view due to the recently reported results from the Mars exploration rovers. Considerable studies have been developed on extreme ecosystems and permafrost in particular, to evaluate the possibility of life on Mars and to test specific automated life detection instruments for space missions. The biodiversity of permafrost located on the Bering Land Bridge National Preserve has been studied as an example of subsurface protected niche of astrobiological interest. Different conventional (enrichment and isolation) and molecular ecology techniques (cloning, fluorescence >in situ> probe hybridization, FISH) have been used for isolation and bacterial identification.The expedition to Imuruk Lake was supported by Centro de Astrobiologia-INTA (Spain). The laboratory experimental procedures were supported by Grant AYA 2010–2013 “Desarrollo de Tecnología para la identificación de vida de forma automática” from the Spanish Government.Peer Reviewe

A Bandwidth Control Arbitration for SoC Interconnections Performing Applications With Task Dependencies

Current System-on-Chips (SoCs) execute applications with task dependency that compete for shared resources such as buses, memories, and accelerators. In such a structure, the arbitration policy becomes a critical part of the system to guarantee access and bandwidth suitable for the competing applications. Some strategies proposed in the literature to cope with these issues are Round-Robin, Weighted Round-Robin, Lottery, Time Division Access Multiplexing (TDMA), and combinations. However, a fine-grained bandwidth control arbitration policy is missing from the literature. We propose an innovative arbitration policy based on opportunistic access and a supervised utilization of the bus in terms of transmitted flits (transmission units) that settle the access and fine-grained control. In our proposal, every competing element has a budget. Opportunistic access grants the bus to request even if the component has spent all its flits. Supervised debt accounts a record for every transmitted flit when it has no flits to spend. Our proposal applies to interconnection systems such as buses, switches, and routers. The presented approach achieves deadlock-free behavior even with task dependency applications in the scenarios analyzed through cycle-accurate simulation models. The synergy between opportunistic and supervised debt techniques outperforms Lottery, TDMA, and Weighted Round-Robin in terms of bandwidth control in the experimental studies performed

Astrobiological field campaign to a volcanosedimentary mars analogue methane producing subsurface protected ecosystem: Imuruk Lake (Alaska)

Viking missions reported adverse conditions for life in Mars surface. High hydrogen signal obtained by Mars orbiters has increased the interest in subsurface prospection as putative protected Mars environment with life potential. Permafrost has attracted considerable interest from an astrobiological point of view due to the recently reported results from the Mars exploration rovers. Considerable studies have been developed on extreme ecosystems and permafrost in particular, to evaluate the possibility of life on Mars and to test specific automated life detection instruments for space missions. The biodiversity of permafrost located on the Bering Land Bridge National Preserve has been studied as an example of subsurface protected niche of astrobiological interest. Different conventional (enrichment and isolation) and molecular ecology techniques (cloning, fluorescence "in situ" probe hybridization, FISH) have been used for isolation and bacterial identificationThe expedition to Imuruk Lake was supported by Centro de Astrobiología-INTA (Spain). The laboratory experimental procedures were supported by Grant AYA 2010–20213 “Desarrollo de Tecnología para la identificación de vida de forma automática” from the Spanish Governmen

SeDeLo: Using semantics and description logics to support aided clinical diagnosis.

Automated medical diagnosis systems based on knowledge-oriented descriptions have gained momentum with the emergence of semantic descriptions. The objective of this paper is to propose a normalized design that solves some of the problems which have been detected by authors in previous tools. The authors bring together two different technologies to develop a new clinical decision support system: description logics aimed at developing inference systems to improve decision support for the prevention, treatment and management of illness and semantic technologies. Because of its new design, the system is capable of obtaining improved diagnostics compared with previous efforts. However, this evaluation is more focused in the computational performance, giving as result that description logics is a good solution with small data sets. In this paper, we provide a well-structured ontology for automated diagnosis in the medical field and a three-fold formalization based on Description Logics with the use of Semantic Web technologiesThis work is supported by the Spanish Ministry of Industry, Tourism, and Commerce under the project TRAZAMED (IPT 090000 2010 007).Publicad

A fast but ill-conditioned formal inverse to Radon transforms in 2D and 3D

We present a formal inversion of the multiscale discrete Radon trasform, valid both for 2D and 3D. With the transformed data from just one of the four quadrants of the direct 2D Radon transform, or one of the twelve dodecants, in case of 3D Radon transform, we can invert exactly and directly, with no iterations, the whole domain. The computational complexity of the proposed algorithms will be O(N log N). With N the total size of the problem, either square or cubic. But this inverse transforms are extremely ill conditioned, so the presence of noise in the transformed domain turns them useless. Still we present both algorithms, and characterize its weakness against noise

Genotoxicity by Electromagnetic Fields

Modern life implies a constant exposure of living organisms to many sources of radiation, especially electromagnetic fields (EMFs) generated by our technological devices. The question of whether or not EMFs in the non-ionizing extremely low frequency (ELF) range can induce genotoxic effects is currently a subject of interest. People of industrialized societies are commonly exposed to EMFs and waves in a very broad range of frequencies, including power lines, telecommunications, and domestic and industrial equipment. In this review, we present controversial evidence from our research group and others of genotoxicity induced by ELF-EMFs, since scientific community consider EMF devices produce marginal amounts of energy, which does not justify any DNA alterations, together with conflicting laboratory results and few epidemiological studies. However, in 2002 the International Agency for Research on Cancer (IARC) categorized ELF-EMFs as being potential carcinogenic and genotoxic agents to humans. The aim of the present chapter is to discuss the role of ELM-EMFs on human genotoxicity

Analysis of Copra and Coconut Oil Markets in Mexico

Abstract Objective: To assess the economic impact of the implementation of different production systems (real, traditional, intensive and organic) on the profits of copra producing states and major coconut oil companies. Design/methodology/approach: A linear programming model was formulated which considered the main costs and production revenues, and the transport costs of the copra and coconut oil market, in order to maximize the profit of copra producers and the oil industry simultaneously. Results: The states that were most suitable in the distribution of copra were Guerrero and Tabasco, which proved to be the main suppliers in all the production systems evaluated; within production systems, the intensive system presented a higher level of profit in the scenarios raised. Limitations/implications: The model considered the sale of copra as the sole income of producers, leaving aside the marketing of other products and economic transfers, thus underestimating their total profit. Future research is required to help collecting data on alternative sources of income from producers.  Findings/conclusions: Increasing copra production without taking into account installed capacity in the industry results in the creation of a copra surplus in most producing states, which would result in a fall in the prices of this producto, therefore, reducing the profit of most states.Objective: To assess the economic impact of the implementation of differentproduction systems (real, traditional, intensive and organic) on the profits of copra-producing states and major coconut oil companies.Design/Methodology/Approach: A linear programming model was formulatedwhich considered the main costs and production revenues, and the transport costs ofthe copra and coconut oil market, in order to maximize the profit of copra producersand the oil industry simultaneously.Results: The states that were most suitable in the distribution of copra wereGuerrero and Tabasco, which proved to be the main suppliers of all the productionsystems evaluated; within production systems, the intensive system presented ahigher level of profit in the scenarios raised.Study Limitations/Implications: The model considered the sale of copra as thesole income of producers, leaving aside the marketing of other products and economic transfers, thus underestimating their total profit. Future research isrequired to help collect data on alternative sources of income for producers.Findings/Conclusions: Increasing copra production without taking into account theinstalled capacity in the industry results in the creation of a copra surplus in mostproducing states, which would result in a fall in the prices of this product, thereforereducing the profit of most states