Minimum entropy restoration using FPGAs and high-level techniques

One of the greatest perceived barriers to the widespread use of FPGAs in image processing is the difficulty for application specialists of developing algorithms on reconfigurable hardware. Minimum entropy deconvolution (MED) techniques have been shown to be effective in the restoration of star-field images. This paper reports on an attempt to implement a MED algorithm using simulated annealing, first on a microprocessor, then on an FPGA. The FPGA implementation uses DIME-C, a C-to-gates compiler, coupled with a low-level core library to simplify the design task. Analysis of the C code and output from the DIME-C compiler guided the code optimisation. The paper reports on the design effort that this entailed and the resultant performance improvements

Restoration of star-field images using high-level languages and core libraries

Research into the use of FPGAs in Image Processing began in earnest at the beginning of the 1990s. Since then, many thousands of publications have pointed to the computational capabilities of FPGAs. During this time, FPGAs have seen the application space to which they are applicable grow in tandem with their logic densities. When investigating a particular application, researchers compare FPGAs with alternative technologies such as Digital Signal Processors (DSPs), Application-Specific Integrated Cir-cuits (ASICs), microprocessors and vector processors. The metrics for comparison depend on the needs of the application, and include such measurements as: raw performance, power consumption, unit cost, board footprint, non-recurring engineering cost, design time and design cost. The key metrics for a par-ticular application may also include ratios of these metrics, e.g. power/performance, or performance/unit cost. The work detailed in this paper compares a 90nm-process commodity microprocessor with a plat-form based around a 90nm-process FPGA, focussing on design time and raw performance. The application chosen for implementation was a minimum entropy restoration of star-field images (see [1] for an introduction), with simulated annealing used to converge towards the globally-optimum solution. This application was not chosen in the belief that it would particularly suit one technology over another, but was instead selected as being representative of a computationally intense image-processing application

Historic Channel Change and Post-Project Analysis of a Habitat Restoration Project on the Upper Strawberry River, Utah

Restoration of the upper Strawberry River included bank stabilization techniques because it was assumed that excessive bank erosion was degrading spawning habitat for Bonneville cutthroat trout (Oncorhynchus clarki Utah)(BCT). Using a long-term aerial photograph record, we determined the historic range of variability in bank erosion rates and channel geometry, and used this information to assess present-day conditions and the rationale for restoration. Relative to historic variability, bank erosion rates were low and channel morphology was stable in the decade prior to restoration. Although a historic loss of riparian vegetation coincided with a shift to a wider and more sinuous channel, lateral migration rates declined to lowest levels in the period-of-record and the channel narrowed as riparian cover increased in the decades prior to restoration. Additionally, the percentage of fine sediment in the streambed prior to restoration was insufficient to impact BCT spawning success. Furthermore, using a 1-D hydraulic model we examined pre- and post-restoration channel morphology and hydraulic variables related to habitat conditions for BCT. The results of the historical analysis suggest that bank erosion and fine sediment did not affect the quality of spawning habitat or the abundance of BCT on the upper Strawberry River. Furthermore, the 1-D hydraulic model shows that the physical in-channel manipulations made little improvements in achieving marketed changes in habitat and as such may have little effect on BCT spawning and resident population success. Our results highlight how a historic analysis can be used to identify the sources of habitat degradation and inform the selection of restoration goals and strategies as well as how surveyed cross-sections coupled with a 1-D hydraulic model can examine initial success of in-stream manipulation for habitat enrichment of a restoration project

Method for Generating, Transmitting, and Receiving Power

Methods are disclosed for converting the heat energy into light energy, typically by generating electricity from the heat energy, and converting the electricity into an optical energy, which is transmitted, and later reconverted to electrical energy for conventional use

Extraordinarily high leaf selenium to sulfur ratios define ‘se-accumulator’ plants

Background and Aims: Selenium (Se) and sulfur (S) exhibit similar chemical properties. In flowering plants (angiosperms) selenate and sulfate are acquired and assimilated by common transport and metabolic pathways. It is hypothesized that most angiosperm species show little or no discrimination in the accumulation of Se and S in leaves when their roots are supplied a mixture of selenate and sulfate, but some, termed Se-accumulator plants, selectively accumulate Se in preference to S under these conditions. Methods: This paper surveys Se and S accumulation in leaves of 39 angiosperm species, chosen to represent the range of plant Se accumulation phenotypes, grown hydroponically under identical conditions. Results: The data show that, when supplied a mixture of selenate and sulfate: (1) plant species differ in both their leaf Se ([Se]leaf) and leaf S ([S]leaf) concentrations; (2) most angiosperms show little discrimination for the accumulation of Se and S in their leaves and, in non-accumulator plants, [Se]leaf and [S]leaf are highly correlated; (3) [Se]leaf in Se-accumulator plants is significantly greater than in other angiosperms, but [S]leaf, although high, is within the range expected for angiosperms in general; and (4) the Se/S quotient in leaves of Se-accumulator plants is significantly higher than in leaves of other angiosperms. Conclusion: The traits of extraordinarily high [Se]leaf and leaf Se/S quotients define the distinct elemental composition of Se-accumulator plants

Implementing Activity-based Costing and its Implications for a Service Firm in the Tme Share Exchange Industry

This study reports on how an activity-based cost accounting (ABC) system was implemented in a service firm in the timeshare exchange industry. In addition, the study highlights the similarities of implementing ABC in a service firm and a manufacturing firm. An important contribution of this field study is to illustrate the separation of labor activities into those that are productive versus those that are not. Further, the study shows the importance of separately allocating the non-productive activities, which are traceable to the primary service lines from those that are not traceable to them. This is analogous to separating the product sustaining activities from the facility sustaining activities when implementing ABC in a manufacturing firm. The Results and Discussion section illustrates the implications of using the ABC information for making decisions about service mix in operating departments, for assessing the implication of employee productivity on service cost, and for service pricing

Job Search and Frictional Unemployment : Some Empirical Evidence

L'auteur du présent article expose les résultats d'une enquête destinée à fournir certaines informations supplémentaires au sujet du chômage frictionnel.Il définit d'abord ce type de chômage à partir d'une formule algébrique, puis indique trois formes de chômage frictionnel: un chômage transitoire résultant de la mise à pied des salariés, un chômage volontaire lorsque ceux-ci quittent volontairement leur emploi, un chômage d'entrée au travail, lorsqu'il s'agit des personnes qui arrivent ou reviennent sur le marché du travail.Dans un deuxième temps, il soulève un autre élément de cette forme de chômage, soit la période plus ou moins longue au cours de laquelle les travailleurs sont à la recherche d'un emploi. Comme le chômage frictionnel est censé se produire lorsque les offres d'emploi sont égales ou supérieures aux demandes d'emploi, il est important de savoir pourquoi les travailleurs ne se placent pas immédiatement. D'une façon générale, on admet que quatre raisons principales peuvent expliquer le chômage frictionnel: 1° les travailleurs peuvent agir au hasard dans la recherche d'un emploi; 2° ils se peut qu'ils soient insuffisamment informés quant aux emplois vacants; 3° ils peuvent se réserver un temps plus ou moins long afin de recueillir des renseignements plus complets; 4° il peut arriver qu'ils mettent délibérément de côté certains emplois vacants.L'auteur, comme bien d'autres économistes, se posent un certain nombre de questions relatives au fait du chômage frictionnel. Les travailleurs en chômage sont-ils insuffisamment informés des conditions du marché du travail? Pendant qu'ils sont sans travail, s'efforcent-t-ils de se renseigner davantage sur l'existence des emplois vacants? Selon quels critères, décident-ils de solliciter un emploi? Tiennent-ils compte des conditions de travail et des taux de salaire?L'auteur a voulu procéder autrement, et voici comment. Il a choisi, aux fins de sa recherche, dans la ville d'Edmonton en Alberta l'endroit où étaient concentrées un grand nombre d'entreprises, soit ce qu'on appelle communément « le centre des affaires. » Il a fait porter son enquête sur une seule occupation, soit celle de dactylo. On leur a demandé combien de temps elles étaient demeurées sans emploi avant d'obtenir leur poste actuel, si elles se trouvaient suffisamment informées lorsqu'elles sont devenues sans travail, quelles furent leurs sources de renseignements au cours de leur périodede chômage et selon quels critères elles ont choisi les entreprises où elles ont postulé des emplois. Enfin, on a tenté de savoir si elles avaient, entre-temps, refusé une offre et si les taux de salaire payés par les employeurs y étaient pour quelque chose.— 68% d'entre elles ont réussi à obtenir leur emploi actuel en moins de quatre semaines, alors que 12 des 21 qui restaient ne se sont pas mises aussitôt en chômage à la recherche d'un nouveau poste. Dans l'ensemble, la durée de la recherche d'un emploi a été de 5.7 semaines.— Au sujet des renseignements nécessaires à la découverte de ce nouvel emploi, 42 employées, 12% d'entre elles seulement, ont déclaré qu'elles n'étaient pas suffisamment informées, alors que 30, ou 45%, estimaient posséder de bonnes ou d'excellentes informations.— Les répondantes estiment aussi qu'elles ne considèrent pas le fait de s'enregistrer aux centres de main-d'oeuvre et aux agences de placement privées comme une activité de cueillette d'information, estimant que ces organismes ne sont que des extensions des bureaux de personnel des entreprises.Finalement, l'Auteur s'est enquis des critères utilisés par les employées pour décider d'accepter un poste. Fait surprenant, 32 dactylos ont rejeté une offre d'emploi et 12 en ont refusé plus d'un. La principale raison de ces refus étaient que les conditions salariales étaient inacceptables.De cette enquête, l'Auteur cherche à tirer quelques conclusions générales. L'hypothèse selon laquelle les travailleurs manquent de renseignements lorsqu'ils tombent en chômage n'est pas confirmée par les résultats de l'enquête.The purpose of this paper is to report on some recent empirical research undertaken in order to provide additional information concerning the frictionally unemployed

General principles of single-construct chromosomal gene drive

Gene drive systems are genetic elements capable of spreading into a population even if they confer a fitness cost to their host. We consider a class of drive systems consisting of a chromosomally located, linked cluster of genes, the presence of which renders specific classes of offspring arising from specific parental crosses unviable. Under permissive conditions, a number of these elements are capable of distorting the offspring ratio in their favor. We use a population genetic framework to derive conditions under which these elements spread to fixation in a population or induce a population crash. Many of these systems can be engineered using combinations of toxin and antidote genes, analogous to Medea, which consists of a maternal toxin and zygotic antidote. The majority of toxin–antidote drive systems require a critical frequency to be exceeded before they spread into a population. Of particular interest, a Z-linked Medea construct with a recessive antidote is expected to induce an all-male population crash for release frequencies above 50%. We suggest molecular tools that may be used to build these systems, and discuss their relevance to the control of a variety of insect pest species, including mosquito vectors of diseases such as malaria and dengue fever