1,711 research outputs found
A Synchronization Library for ASIM
No full textThis memo describes the functions in the synchronization library provided for programs written for ASIM and acts as a user's manual. Mul-T provides futures and binary semaphores as primitive synchronization mechanisms. For experimenting with other synchronization constructs, we have extended the language to include J-structures, L-structures, mutualexclusion locks, counting semaphores and barriers. An extension of futures to allow thread placement directives is also provided. 1 Introduction A synchronization library is provided in ASIM for users to experiment with various synchronization mechanisms. This memo assumes knowledge of programming in the ASIM environment. See Alewife Memo 13 for a description of the ASIM environment. The library contains implementations of mutual-exclusion locks, counting semaphores, Jstructures, L-structures, and barriers. These supplement the synchronization mechanisms already present in Mul-T on ASIM, viz., futures, and binary semaphores. This memo will b..
Relocation of the Atmosphere-Space Interactions Monitor (ASIM) on the International Space Station
No full textThe Atmosphere-Space Interactions Monitor (ASIM) is a 314-kilogram external payload attached to the Columbus module of the International Space Station (ISS). It was developed by the European Space Agency (ESA) and the main objective of ASIM is the study of the upper layers of the atmosphere and in particular, phenomena known as Transient Luminous Events and Terrestrial Gamma-ray Flashes. On board since April 2018, ASIM has produced outstanding science. ASIM mission was supposed to end in December 2021 when another payload was programmed to use its location. With its excellent health and science output, the idea was put forward to relocate ASIM somewhere else on the station instead of simply removing and trashing it. With very little lead time, the ground teams managed to overcome all the hurdles to make this relocation possible. From a nadir viewing payload, designed to monitor the top of thunderstorms, ASIM has become a limb viewing one since January 2022. Remarkably, a limb viewing instrument was in the original plans for ASIM, but was descoped for financial reasons. The science produced at this new location is therefore quite complementary to the original location
An extension of the localist representation theory: grandmother cells are also widely used in the brain
No full textabstract: Based on considerable neurophysiological evidence, Roy (2012) proposed the theory that localist representation is widely used in the brain, starting from the lowest levels of processing. Grandmother cells are a special case of localist representation. In this article, I present the theory that grandmother cells are also widely used in the brain. To support the proposed theory, I present neurophysiological evidence and an analysis of the concept of grandmother cells. Konorski (1967) first predicted the existence of grandmother cells (he called them “gnostic” neurons)—single neurons that respond to complex stimuli such as faces, hands, expressions, objects, and so on. The term “grandmother cell” was introduced by Jerry Lettvin in 1969 (Barlow, 1995).View the article as published at http://journal.frontiersin.org/article/10.3389/fpsyg.2013.00300/ful
Documentation of the Central and Eastern European Countries Agricultural Simulation Model (CEEC-ASIM Version 1.0)
No full textThe Central and Eastern European Countries Agricultural Simulation Model (CEEC-ASIM) has been developed at IAMO. It is a partial equilibrium model for the agricultural sectors of 14 countries including demand of domestic consumers and is designed to analyse the impacts of agricultural policies on important target variables like producer and consumer prices, supply and input demand of agriculture, food demand, net trade and welfare. Particular efforts were undertaken to implement also the policy instruments of the Common Agricultural Policy of the European Union. These besides the market price support measures also include the different forms of domestic support as for example area payments and beef premiums. Also the set-aside obligations and production quotas can be taken into account. This discussion paper serves as a model documentation and describes the structure of the model along with the basic modelling assumptions. The model is essentially based on neoclassical theory. The main hypotheses are perfect markets, profit maximisation of producers and utility maximisation of consumers. -- G E R M A N V E R S I O N: Das Central and Eastern European Countries Agricultural Simulation Model (CEEC-ASIM) ist am IAMO entwickelt worden. Es ist ein partiales Gleichgewichtsmodell für die Agrarsektoren von 14 Ländern und umfasst auch die Nachfrage der Verbraucher. Insbesondere ist es für die Analyse der Auswirkungen von Agrarpolitiken auf wichtige Zielgrößen wie die Erzeuger- und Verbraucherpreise, Angebots- und Faktornachfragemengen der Landwirtschaft, Konsumentennachfrage, Nettohandel und Wohlfahrt erstellt worden. Besondere Anstrengungen sind unternommen worden, die Instrumente der Gemeinsamen Agrarpolitik der Europäischen Union in das Modell einzubeziehen. Diese umfassen neben den Maßnahmen der Marktpreisstützung auch verschiedene Formen der internen Stützung wie zum Beispiel die Flächenzahlungen und Prämien im Rindfleischbereich. Auch können Flächenstilllegungsverpflichtungen sowie Produktionsquoten berücksichtigt werden. Dieses Diskussionspapier dient als Dokumentation und beschreibt die Struktur des Modells sowie die grundlegenden Modellannahmen. Das Modell basiert im Wesentlichen auf der neoklassischen Theorie. Die zentralen Hypothesen sind vollständige Märkte, gewinnmaximierende Produzenten und nutzenmaximierende Konsumenten.Sector Modelling,Agricultural Sector,Partial Equilibrium Model,Policy Analyses,Sektormodellierung,Agrarsektor,partielles Gleichgewichtsmodell,Politik Analyse
Frequency-domain analysis and optimisation of linear networks
No full textThe objective of the research conducted in this thesis is the development of a package for computer-aided frequency-domain analysis and optimisation of large-scale linear electrical networks on a small interactive computer. To enable the implementation of such a package on asmall machine, and for efficient analysis, the network under consideration must be described in terms of nested subnetworks. In this case the required network analysis may be carried in a hierarchical fashion; starting with the smallest (or deepest) subnetwork and ending with the whole given network. The calculation of the admittance parameters of the equivalent three-pole of each de-nested subnetwork is central to the scheme. This is achieved in an efficient manner by using a suitable partitioning strategy whereupon an L-U factorisation technique, with its attendant forward and backward substitutions, is used to solve for the required admittance parameters. From these admittance parameters many other network functions are readily derived. The other possible analysis using the present package is the first-order linear network sensitivity analysis. A new scheme to allow this analysis to be carried out for networks including nested subnetworks is described. This scheme relies, for its efficiency, on the results of the a.c. analysis using the L-U factorisation technique, and on the use of the adjoint network concept. The implementations of this integrated scheme of analyses proved it to be both efficient and reliable optimisation of this category of networks to voltage-gain Modulus and/or Phase output specifications is carried out using an existing nonlinear programming algorithm. An appropriate transformation of design variables enables the use of an unconstrained minimisation of a least-square type of error function, to solve the optimisation problem. The user is allowed to define the performance specifications either as an upper and lower bound, or as a spot-on value, at each frequency point of interest. Since the use of gradient information enhances the speed of convergence of the minimisation process, the analyses algorithm in our package calculates the gradient vector and passes this information to the optimisation routine. From this gradient information, the latter calculates an initial estimate of the Hessian matrix. Several examples of network simulation and optimisation are introduced to demonstrate both the capababilities and efficiency of the package.</p
Conditional cash transfers and female schooling : the impact of the female school stipend program on public school enrollments in Punjab, Pakistan
No full textInstead of mean-tested conditional cash transfer (CCT) programs, some countries have implemented gender-targeted CCTs to explicitly address intra-household disparities in human capital investments. This study focuses on addressing the direct impact of a female school stipend program in Punjab, Pakistan: Did the intervention increase female enrollment in public schools? To address this question, the authors draw on data from the provincial school censuses of 2003 and 2005. They estimate the net growth in female enrollments in grades 6-8 in stipend eligible schools. Impact evaluation analysis, including difference-and-difference (DD), triple differencing (DDD), and regression-discontinuity design (RDD) indicate a modest but statistically significant impact of the intervention. The preferred estimator derived from a combination of DDD and RDD empirical strategies suggests that the average program impact between 2003 and 2005 was an increase of six female students per school in terms of absolute change and an increase of 9 percent in female enrollment in terms of relative change. A triangulation effort is also undertaken using two rounds of a nationally representative household survey before and after the intervention. Even though the surveys are not representative at the subprovincial level, the results corroborate evidence of the impact using school census data.Education For All,Primary Education,Tertiary Education,Gender and Education,Education Reform and Management
Computational Fluid Dynamics Based Diagnostics and Optimal Design of Hydraulic Capsule Pipelines
No full textScarcity of fossil fuels and rapid escalation in the energy prices around the world is affecting efficiency of established modes of cargo transport within transportation industry. Extensive research is being carried out on improving efficiency of existing modes of cargo transport, as well as to develop alternative means of transporting goods. One such alternative method can be through the use of energy contained within fluid flowing in pipelines in order to transfer goods from one place to another. Although the concept of using fluid pipelines for transportation purposes has been in practice for more than a millennium now, but the detailed knowledge of the flow behaviour in such pipelines is still a subject of active research. This is due to the fact that most of the studies conducted on transporting goods in pipelines are based on experimental measurements of global flow parameters, and only a rough approximation of the local flow behaviour within these pipelines has been reported. With the emergence of sophisticated analytical tools and the use of high performance computing facilities being installed throughout the globe, it is now possible to simulate the flow conditions within these pipelines and get better understanding of the underlying flow phenomena.
The present study focuses on the use of advanced modelling tools to simulate the flow within Hydraulic Capsule Pipelines (HCPs) in order to quantify the flow behaviour within such pipelines. Hydraulic Capsule Pipeline is the term which refers to the transport of goods in hollow containers, typically of spherical or cylindrical shapes, termed as capsules, being carried along the pipeline by water. A novel modelling technique has been employed to carry out the investigations under various geometric and flow conditions within HCPs.
Both qualitative and quantitative flow diagnostics has been carried out on the flow of both spherical and cylindrical shaped capsules in a horizontal HCP for on-shore applications. A train of capsules consisting of a single to multiple capsules per unit length of the pipeline has been modelled for practical flow velocities within HCPs. It has been observed that the flow behaviour within HCP depends on a number of fluid and geometric parameters. The pressure drop in such pipelines cannot be predicted from established methods. Development of a predictive tool for such applications is one of the aims that is been achieved in this study. Furthermore, investigations have been conducted on vertical pipelines as well, which are very important for off-shore applications of HCPs. The energy requirements for vertical HCPs are significantly higher than horizontal HCPs. It has been shown that a minimum average flow velocity is required to transport a capsule in a vertical HCP, depending upon the geometric and physical properties of the capsules. The concentric propagation, along the centreline of pipe, of heavy density capsules in vertical HCPs marks a significant variation from horizontal HCPs transporting heavy density capsules.
Bends are an integral part of pipeline networks. In order to design any pipeline, it is essential to consider the effects of the bends on the overall energy requirements within the pipelines. In order to accurately design both horizontal and vertical HCPs, analysis of the flow behaviour and energy requirements, of varying geometric configurations, has been carried out. A novel modelling technique has been incorporated in order to accurately predict the velocity, trajectory and orientation of the capsules in pipe bends.
Optimisation of HCPs plays a crucial rule towards worldwide commercial acceptability of such pipelines. Based on Least-Cost Principle, an optimisation methodology has been developed for single stage HCPs for both on-shore and off-shore applications. The input to the optimisation model is the solid throughput required from the system, and the outputs are the optimal diameter of the HCPs and the pumping requirements for the capsule transporting system. The optimisation model presented in the present study is both robust and user-friendly.
A complete flow diagnostics and design, including optimisation, of Hydraulic Capsule Pipelines has been presented in this study. The advanced computational skills being incorporated in this study has made it possible to map and analyse the flow structure within HCPs. Detailed analysis on even the smallest scale flow variations in HCPs has led to a better understanding of the flow behaviour
Stability of the solitary wave boundary layer subject to finite-amplitude disturbances
No full text10.1017/jfm.2020.351JOURNAL OF FLUID MECHANICS89
Correspondence to Joseph E. Lowery from Asim Israel, August 29, 1986
No full textA letter to Joseph E. Lowery from Asim Israel of the House of Israel requesting assistance in contacting Louis Stokes, Jesse Jackson, and Reverend Clay Evans to convince the Guyana government to release David Hill from prison. 1 page.The Atlanta University Center Robert W. Woodruff Library acknowledges the generous support of the Joseph & Evelyn Lowery Institute for Justice and Human Rights, the Joseph Echols Lowery Irrevocable Trust, and other donors in supporting the processing and digitization of Morehouse College's Joseph Echols and Evelyn Gibson Lowery Collection
Responsible conduct and documentation of research: a standard operating procedure template that can be customized
No full textIf you have comments or suggestions for improvements, please direct these to the corresponding author, Catherine Hayward ([email protected]).This standard operating procedure (SOP) document was prepared as a template that individual researchers can customize for their own use. Prior to publication, this SOP underwent peer review by the McMaster University Faculty of Health Sciences Research Council. The Council has endorsed the publication of this SOP to encourage researchers to develop procedures that encourage best research practices and can be customized to meet specific needs.
Should you decide to customize this SOP for your own use, please acknowledge the original authors, who include Ms. D’Andra Parker and Mr. Asim Soomro (graduate students in the Hayward laboratory). All items highlighted in yellow in the SOP must be customized.
This procedure outlines the steps involved in proper recording keeping in the laboratory. This SOP applies any/all data generated while in the laboratory, and any/all the laboratory records
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