A Belgian Transect: Field Broadcast in the expanded field of ecology

Abstract

This article sets out the notion of a Field Broadcast from the dual perspective of Rebecca Birch, one of the developers of a bespoke version of Flash Media Live Encoder and Bram Thomas Arnold, an artist who uses a case study from Sideways Festival, Belgium, 2012. Field Broadcast enables an artist to be in a field, suitably equipped, and stream live footage to an audience. It is an experiment in place, site and the notion of a field. It is a new method of making work in the space between site-specific performance and the digital realm: a way of working that enables artists to generate new artworks within the non-place of the Internet. Birch introduces the technology from a number of perspectives before it is fleshed out with evidence and experience from a live project that took place in Belgium in 2012. Sideways was a festival that traversed Belgium over four weeks and 400?km, with artists walking and generating work en route. The possibilities offered by Field Broadcast are explored in relation to the expanded field of ecology amidst Bourriaud's The Radicant (2009), Guatarri's The Three Ecologies (2005) and Morton's Ecology Without Nature (2007 Morton, Timothy. 2007. Ecology Without Nature. Cambridge, MA: Harvard University Press. [Google Scholar]).     

Open and Reconfigurable Hypermedia Systems: A Filter-Based Model

The need for open hypermedia systems has been well-argued by various authors. In this paper we discuss the Microcosm model for open hypermedia and show how filters have been used to extend this model both for greater efficiency and to make it totally reconfigurable. This enables users to tailor the functionality of the system to meet their own requirements, for example to select different sets of links, or to add navigation tools. The implementation of a management system for filters is described, and examples of how it has been used to extend the functionality of the model are presented, in particular the use of filters to design and implement a set of navigation tools for Microcosm. This latter case study demonstrates the power and flexibility of the filter-based model since all navigation tools for the system can be implemented as filters. The filter technology is discussed in the context of Microcosm but can be generalised to other hypermedia systems.     

Optimal resource allocation for time-reservation systems

This paper studies the optimal resource allocation in time-reservation systems. Customers arrive at a service facility and receive service in two steps; in the first step information is gathered from the customer, which is then sent to a pool of computing resources, and in the second step the information is processed after which the customer leaves the system. A central decision maker has to decide when to reserve computing power from the pool of resources, such that the customer does not have to wait for the start of the second service step and that the processing capacity is not wasted due to the customer still being serviced at the first step. The decision maker simultaneously has to decide on how many processors to allocate for the second processing step such that reservation and holding costs are minimized. Since an exact analysis of the system is difficult, we decompose the system into two parts which are solved sequentially leading to nearly optimal solutions. We show via dynamic programming that the near-optimal number of processors follows a step function with as an extreme policy the bang-bang control. Moreover, we provide new fundamental insights in the dependence of the near-optimal policy on the distribution of the information gathering times. Numerical experiments demonstrate that the near-optimal policy closely matches the performance of the optimal policy of the original problem.     

An intelligent forecasting model based on robust wavelet ν-support vector machine

Aiming at the problem of small samples, season character, nonlinearity, randomicity and fuzziness in product demand series, the existing support vector kernel does not approach the random curve of the demands time series in the L²(Rⁿ) space (quadratic continuous integral space). The robust loss function is also proposed to solve the shortcoming of ε-insensitive loss function during handling hybrid noises. A novel robust wavelet support vector machine (RW ν-SVM) is proposed based on wavelet theory and the modified support vector machine. Particle swarm optimization algorithm is designed to select the optimal parameters of RW ν-SVM model in the scope of constraint permission. The results of application in car demand forecasts show that the forecasting approach based on the RW ν-SVM model is effective and feasible, the comparison between the method proposed in this paper and other ones is also given which proves this method is better than RW ν-SVM and other traditional methods.     

Placement Strategies for Internet-Scale Data Stream Systems

Optimally assigning streaming tasks to network machines is a key factor that influences a large data-stream-processing system's performance. Although researchers have prototyped and investigated various algorithms for task placement in data stream management systems, taxonomies and surveys of such algorithms are currently unavailable. To tackle this knowledge gap, the authors identify a set of core placement design characteristics and use them compare eight placement algorithms. They also present a heuristic decision tree that can help designers judge how suitable a given placement solutions might be to specific problems.     

Stability of a Trajectory‐Based Control Law for an Unknown Nonlinear Non‐Minimum Phase System

We investigate the stability of an unknown nonlinear discrete‐time non‐minimum phase system under a trajectory‐based control law. The system can be regarded as a first‐order approximation to a continuous‐time system. Hence, one of the parameters in the discrete‐time system equation can be regarded as the “sampling interval”. We show that, subject to certain conditions, as long as the sampling interval is neither too short nor too long, the closed‐loop system is stable in a certain sense.     

Dietary CLA alters yolk and tissue FA composition and hepatic histopathology of laying hens

The effect of dietary CLA along with n-3 PUFA on yolk FA profile and hepatic lipid accumulation was investigated. Laying hens (n=40) were randomly assigned to four experimental diets containing 0, 0.5, 1.0, or 2.0% CLA. Menhaden oil was used as the source of n-3 PUFA. Dietary CLA did not affect the total lipid content of egg yolk (P>0.05). The amounts of CLA isomers (cis-9 trans-11, trans-10 cis-12) in the egg yolk were proportional to the levels of CLA in the diet (P<0.05). The total CLA content in the egg yolk was 0, 0.97, 2.4, and 5.3 wt%, respectively (P<0.05). Addition of CLA resulted in an increase in saturated FA (P<0.05) with a concomitant reduction in monounsaturated FA (P<0.05) in the yolk, liver, abdominal fat, breast, and thigh muscle. No difference in saturated and monounsaturated FA content in heart and spleen tissue was noted. Dietary CLA at all concentrations resulted in an increase (P<0.05) in the total number of fat vacuoles and lipid infiltration in hepatocytes. The number of cells with 75% or higher lipid vacuolation in the cytoplasm was also increased (P<0.05) by 2.0% CLA. Dietary CLA at 0.5% levels resulted in an increase (P<0.05) in the total lipid content of hepatic tissue. The total lipid content in leg muscle was lower (P<0.05) in CLA-fed birds. However, no effect of CLA on lipid content of breast muscle, heart, spleen and adipose tissue was observed (P>0.05). The current study used CLA in a FFA form. The effects of using CLA in other form such as TG on avian hepatic tissue need to be investigated.     

Thermal Conductivity of Zinc Oxide: From Green to Sintered State

The thermal conductivity of ZnO with different particle sizes (micrometer, submicrometer, and nanometer) was measured using the laser flash technique. As the "green" samples were heated from room temperature to 600°C (and 1000°C) and then cooled down to room temperature, the thermal conductivity was measured in situ . A model for interparticle neck growth was developed based on mass transfer to the neck region of a powder as a result of known temperature. By combining this model with a three-dimensional numerical code, the thermal conductivity of ZnO was calculated. Excellent agreement between the theoretical calculation and experimental data was found.     

Herbivory induces systemic production of plant volatiles that attract predators of the herbivore: Extraction of endogenous elicitor

It was previously shown that in response to infestation by spider mites (Tetranychus urticae), lima bean plants produce a volatile herbivoreinduced synomone that attracts phytoseiid mites (Phytoseiulus persimilis) that are predators of the spider mites. The production of predator-attracting infochemicals was established to occur systemically throughout the spider mitein-fested plant. Here we describe the extraction of a water-soluble endogenous elicitor from spider mite-infested lima bean leaves. This elicitor was shown to be transported out of infested leaves and was collected in water in which the petiole of the infested leaf was placed. When the petioles of uninfested lima bean leaves were placed in water in which infested leaves had been present for the previous seven days, these uninfested lima bean leaves became highly attractive to predatory mites in an olfactometer when an appropriate control of uninfested lima bean leaves was offered as alternative. The strength of this effect was dependent on the number of spider mites infesting the elicitor-producing leaves. Higher numbers of spider mites resulted in an elicitor solution with a stronger effect. In addition, spider mite density was important. The elicitor obtained from one leaf with 50 spider mites had a stronger effect on the attractiveness of uninfested leaves than the elicitor obtained from three leaves with 17 spider mites each. This suggests that the stress intensity imposed on a plant is an important determinant of the elicitor quantity. While the elicitor has a strong effect on the attractiveness of uninfested leaves, spider mite-infested leaves are still much more attractive to predatory mites than elicitor-exposed leaves. The data are discussed in the context of systemic effects in plant defense and the biosynthesis of herbivore-induced terpenoids in plants.     

Crosslinking and decomposition reactions of epoxide‐functionalized polynorbornene. II. Impact of reactions on mechanical properties

Low dielectric constant materials are critical to meeting the demand for continual reduction in feature sizes and increase in interconnect density required for future high‐speed microelectronic devices. Polymers based on functionalized norbornenes are inherently attractive for these applications as they exhibit good electrical properties such as a low dielectric constant and appealing mechanical properties. Although polynorbornenes inherently possess properties that are attractive for microelectronics packaging, films of these polymers are not solvent‐resistant. Solvent‐resistant crosslinked films can be attained by generation of acid species to promote cationic crosslinking of epoxide side groups. This article is the second part of a two‐part study investigating the crosslinking of a copolymer of decyl norbornene and epoxide norbornene. In the first part of this study, it was proposed that epoxide decomposition reactions are also possible at cure temperatures greater than 160°C. This decomposition mechanism results in the complete loss of crosslinkable epoxide groups while leaving the norbornene backbone intact. Although crosslinking and decomposition reactions have independent mechanisms, both reactions directly affect the level of crosslinking. In this part of the study, the solvent swelling behavior, tensile modulus, elongation to break, and residual stress were investigated for polymer films cured under various conditions to validate the proposed mechanisms. The trends observed with these properties are consistent with the counteracting nature of epoxide crosslinking and decomposition reactions. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 91: 1020–1029, 2004