An FPGA-based real-time event sampler

This paper presents the design and FPGA-implementation of a sampler that is suited for sampling real-time events in embedded systems. Such sampling is useful, for example, to test whether real-time events are handled in time on such systems. By designing and implementing the sampler as a logic analyzer on an FPGA, several design parameters can be explored and easily modified to match the behavior of different kinds of embedded systems. Moreover, the trade-off between price and performance becomes easy, as it mainly exists of choosing the appropriate type and speed grade of an FPGA family

A Performance Comparison between Enlightenment and Emulation in Microsoft Hyper-V

Microsoft MS Hyper-V is a native hypervisor that enables platform virtualization on x86-64 systems It is a microkernelized hypervisor where a host operating system provides the drivers for the hardware This approach leverages MS Hyper-V to support enlightenments the Microsoft name for Paravirtualization in addition to the hardware emulation virtualization technique This paper provides a quantitative performance comparison using different tests and scenarios between enlightened and emulated Virtual Machines VMs hosted by MS Hyper-V server 2012 The experimental results show that MS enlightenments improve performance by a factor of more than tw

Customisation and urban design: evaluating the role of informal street user modifications in the distribution of static activities and perceptions of streetscape settings

Since the mid-twentieth century, the urban planning and design practices have battled to counter their association with the creation of dead urban spaces. This deadness is conveyed in their lack of pedestrian activities – conviviality, spatial interactions – and negative perceptions of such spaces. In a variety of ways, urban design theorists have suggested that the negative impressions of planning are connected to the system’s inability to acknowledge the opinions of those subjected to it. The process of producing public spaces often result in inflexible scenarios that fail to acknowledge constantly changing end-user requirements. In several narratives, planning processes are compared to the monotony of mass-production processes – a linear process that limits participation and variety in designs by their end-users. Today, manufacturing processes offer mass-customisation as an approach towards diversifying end products, devolving design powers to customers who informally modify and optimise their products. Mass-customisation allows for end-user modifications throughout a product’s creation and post-construction. While collaborative design is embedded into many urban design processes, comparable flexibilities and successes observed in mass-customisation are not apparent. Through the empirical study of three London retail high streets, with contrasting population demographics, the impacts of informally customised streetscape features on the distribution of static pedestrian activities are scrutinised. Evidence is tested against the opinions of a selection of pedestrians distributed in streetscape regions with varying intensities of customisation. This research finds that an increased presence of customisation results in increased pedestrian activities, vitality, and positive spatial perceptions. It also finds that there is an optimal level of complexity associated with informal modifications, corresponding with past studies concerning the negative impacts of over complexity on human responses to spatial settings – a theoretical threshold. Therefore, moderate implementations of customisation are linked to the increased clustering of static activities and satisfaction across varied demographics and spatial settings

The role of hydrothermal activity in the formation of karst-hosted manganese deposits of the Postmasburg Mn Field, Northern Cape Province, South Africa

The Postmasburg Manganese Field (PMF), Northern Cape Province, South Africa, once represented one of the largest sources of manganese ore worldwide. Two belts of manganese ore deposits have been distinguished in the PMF, namely the Western Belt of ferruginous manganese ores and the Eastern Belt of siliceous manganese ores. Prevailing models of ore formation in these two belts invoke karstification of manganese-rich dolomites and residual accumulation of manganese wad which later underwent diagenetic and low-grade metamorphic processes. For the most part, the role of hydrothermal processes and metasomatic alteration towards ore formation has not been adequately discussed. Here we report an abundance of common and some rare Al-, Na-, K- and Ba-bearing minerals, particularly aegirine, albite, microcline, banalsite, sérandite-pectolite, paragonite and natrolite in Mn ores of the PMF, indicative of hydrothermal influence. Enrichments in Na, K and/or Ba in the ores are generally on a percentage level for most samples analysed through bulk-rock techniques. The presence of As-rich tokyoite also suggests the presence of As and V in the hydrothermal fluid. The fluid was likely oxidized and alkaline in nature, akin to a mature basinal brine. Various replacement textures, particularly of Na- and K- rich minerals by Ba-bearing phases, suggest sequential deposition of gangue as well as ore-minerals from the hydrothermal fluid, with Ba phases being deposited at a later stage. The stratigraphic variability of the studied ores and their deviation from the strict classification of ferruginous and siliceous ores in the literature, suggests that a re-evaluation of genetic models is warranted. New Ar-Ar ages for K-feldspars suggest a late Neoproterozoic timing for hydrothermal activity. This corroborates previous geochronological evidence for regional hydrothermal activity that affected Mn ores at the PMF but also, possibly, the high-grade Mn ores of the Kalahari Manganese Field to the north. A revised, all-encompassing model for the development of the manganese deposits of the PMF is then proposed, whereby the source of metals is attributed to underlying carbonate rocks beyond the Reivilo Formation of the Campbellrand Subgroup. The main process by which metals are primarily accumulated is attributed to karstification of the dolomitic substrate. The overlying Asbestos Hills Subgroup banded iron formation (BIF) is suggested as a potential source of alkali metals, which also provides a mechanism for leaching of these BIFs to form high-grade residual iron ore deposits

RTS hypervisor qualification for real-time systems

Virtualization is a synonym for the server and cloud computing arena. Recently, it started to be also applied to real-time embedded systems with timing constraints. However, virtualization products for data centers and desktop computing cannot be readily applied to embedded systems because of differences in requirements, use cases, and computer architecture. Bridging the gap between virtualization and real-time requirements imposes the need of real-time virtualization products. Therefore, some embedded software manufacturers have built several real-time hypervisors specialized for embedded systems. Currently, there are several commercial ones such as Greenhills INTEGRITY MultiVisor, Real-Time Systems (RTS) GmbH Hypervisor, Tenasys eVM for Windows, National Instruments Real-Time Hyper Hypervisor, and some others. This paper provides the behavior and performance results of evaluating RTS hypervisor and gives advices of its use for soft or hard real-time embedded systems

Real-time capabilities in the standard Linux Kernel: How to enable and use them?

Linux was originally designed as a general purpose operating system without consideration for real-time applications. Recently, it has become more attractive to the real-time community due to its low cost and open source approach. In order to help the real-time community, we will present in this paper the practical steps required to achieve a real-time Linux by applying the PREEMPT-RT patches which will provide Linux with these capabilities. We will also focus on some of the kernel configuration that should get attention while building the kernel in order to maintain the real-time behavior of the system during runtime. DOI: 10.17762/ijritcc2321-8169.15012

Permian 40Ar/39Ar ages for post-Variscan minor intrusions in the Iberian Range and Spanish Central System

40Ar/39Ar dating of biotite from a calc-alkaline gabbro stock NW of Loscos in the Iberian Range yielded a slightly disturbed gas release spectrum. It has an early Permian, 288.5 ± 1.4 Ma total gas age, interpreted as the minimum emplacement age. The 40Ar/39Ar apparent age of the gabbro agrees with the Autunian stratigraphic age of related volcanic rocks. 40Ar/39Ar step-heating dating of amphibole phenocrysts from an alkaline camptonite dyke ca. 4 km SE of El Hoyo de Pinares in the Sierra Guadarrama sector of the Spanish Central System yielded a mid-Permian 264 ± 3 Ma plateau age, interpreted as the emplacement age. The age is indistinguishable from published 40Ar/39Ar amphibole ages for N-S trending camptonite dykes from the western, Sierra de Gredos segment of the Central System. This suggests that the camptonite dykes from both sectors belong to the same generation

The dicistronic RNA from the mouse LINE-1 retrotransposon contains an internal ribosome entry site upstream of each ORF: implications for retrotransposition

Most eukaryotic mRNAs are monocistronic and translated by cap-dependent initiation. LINE-1 RNA is exceptional because it is naturally dicistronic, encoding two proteins essential for retrotransposition, ORF1p and ORF2p. Here, we show that sequences upstream of ORF1 and ORF2 in mouse L1 function as internal ribosome entry sites (IRESes). Deletion analysis of the ORF1 IRES indicates that RNA structure is critical for its function. Conversely, the ORF2 IRES localizes to 53 nt near the 3′ end of ORF1, and appears to depend upon sequence rather than structure. The 40 nt intergenic region (IGR) is not essential for ORF2 IRES function or retrotransposition. Because of strong cis-preference for both proteins during L1 retrotransposition, correct stoichiometry of the two proteins can only be achieved post-transcriptionally. Although the precise stoichiometry is unknown, the retrotransposition intermediate likely contains hundreds of ORF1ps for every ORF2p, together with one L1 RNA. IRES-mediated translation initiation is a well-established mechanism of message-specific regulation, hence, unique mechanisms for the recognition and control of these two IRESes in the L1 RNA could explain differences in translational efficiency of ORF1 and ORF2. In addition, translational regulation may provide an additional layer of control on L1 retrotransposition efficiency, thereby protecting the integrity of the genome

Electric Dipole Radiation from Spinning Dust Grains

We discuss the rotational excitation of small interstellar grains and the resulting electric dipole radiation from spinning dust. Attention is given to excitation and damping of rotation by: collisions with neutrals; collisions with ions; plasma drag; emission of infrared radiation; emission of microwave radiation; photoelectric emission; and formation of H_2 on the grain surface. We introduce dimensionless functions F and G which allow direct comparison of the contributions of different mechanisms to rotational drag and excitation. Emissivities are estimated for dust in different phases of the interstellar medium, including diffuse HI, warm HI, low-density photoionized gas, and cold molecular gas. Spinning dust grains can explain much, and perhaps all, of the 14-50 GHz background component recently observed in CBR studies. It should be possible to detect rotational emission from small grains by ground-based observations of molecular clouds.Comment: 59 pages, 19 eps figures, uses aaspp4.sty . Submitted to Ap.