4,377 research outputs found
Definitive principles and the specification of software
No full textWe investigate a novel approach to programming and specification that aims to support both incremental development and interactive validation. The specification of the behaviour of several agents interacting in a room is viewed as a process of design and simulation. The resemblance between state changes in design (such as moving a shelf) and those in simulation (such as opening a door) motivates a unified representation. The distinction between design and simulation is conventionally reflected in the representation (cf the editing and execution of a program), but it can be better understood in terms of the privileges for action of agents. The action of an agent in a state is expressed within a definitive (definition-based) programming paradigm by a system of definitions specifying systems within an appropriate abstract family of variables. Such use of definitive systems within an appropriate abstract machine model facilitates the representation of the actions associated with each agent and the formalisation of a design in terms of possible agent interactions. The paper concludes with a brief review of the progress to date on the definitive programming project
ELECTRICAL AND OPTICAL-PROPERTIES OF DEEP-RED TOP-SURFACE-EMITTING LASERS
No full textBy studying thermal behavior of all-MBE surface-emitting lasers, barrier heights and optimum cavity design parameters are obtained. The barrier heights for holes between hetero-interfaces of Al0.3Ga0.7As-Al0.65Ga0.35As and AlAsAl0.65Ga0.35As (DELTAx = 0.35) are measured to be 77 meV at zero bias for the deep-red top-surface-emitting laser. The barrier height decreases linearly with forward bias voltage, explaining the nonlinearity in current-voltage characteristics of the top-surface-emitting laser. The contribution of electrons to electrical resistance is estimated to be negligibly small compared to that of holes for the structure consisting of DELTAx = 0.35. Minimum threshold current and maximum differential quantum efficiency observed around 200 K indicates slight mismatch between gain maximum and Fabry-Perot resonance for the deep-red top-surface-emitting laser
Doped fibre length and pump power of gain-flattened EDFAs
No full textA simple method for determining the doped fibre length and the pump power of gain-flattened EDFAs has been proposed on the basis of average inversion of the erbium ions with maximum gain flatness. The difference between the obtained and the desired gains to achieve the output power per channel of -5 -5dBm while maintaining the maximum gain flatness was <+/-0.3dB
Evaluating definitive principles for interaction in graphics
No full textThis paper is an appraisal of current progress towards supporting interactive graphics within the framework of a general-purpose programming paradigm based upon definitions. It considers how the use of definitive principles relates to other work, why it appears promising, and what progress has been made towards the resolution of technical difficulties. It re-examines potential for applications of definitive principles in interactive graphics in the light of more recently developed ideas about dealing with control issues and dynamically changing relationships in a definitive programming framework. It also takes account of new research into notations for graphics that makes use of geometrical constructions. As a subsidiary theme, the paper contrasts the support for reference and representation of geometric relationships in various kinds of interactive graphics systems
PiLa-CS Professional Learning Community - Workshop 2 Resources
No full textDuring the Summer of 2021 and 2022, the Participating in Literacies and Computer Science (PiLa-CS) Research Practice Partnership convened and supported a community of practice to learn more about how to enable better CS teaching for emergent bilinguals. These are materials from Workshop 2 of the PLC.Sponsored by the National Science Foundation under NSF grant CNS-1738645 and DRL-1837446. Any opinions, findings, and conclusions or recommendations expressed in this material are those of the author(s) and do not necessarily reflect the views of the National Science Foundation
Translanguaging Pedagogy in CS Ed
No full textEpisode 3: Translanguaging pedagogy in CS Education
This video looks at how multilingual students already use translanguaging in their computer science classes and discusses how CS educators can further support them with translanguaging pedagogy, a framework that prompts teachers to consider their stance, design, and shifts.
Featuring team members from Participating in Literacies and Computer Science (PiLa-CS), https://www.pila-cs.orgEpisode 3: Translanguaging pedagogy in CS Education
This video looks at how multilingual students already use translanguaging in their computer science classes and discusses how CS educators can further support them with translanguaging pedagogy, a framework that prompts teachers to consider their stance, design, and shifts.
Featuring team members from Participating in Literacies and Computer Science (PiLa-CS), https://www.pila-cs.orgSponsored by the National Science Foundation under NSF grant CNS-1738645 and DRL-1837446. Any opinions, findings, and conclusions or recommendations expressed in this material are those of the author(s) and do not necessarily reflect the views of the National Science Foundation
PiLa-CS Professional Learning Community - Design Journal Template
No full textDuring the Summer of 2021 and 2022, the Participating in Literacies and Computer Science (PiLa-CS) Research Practice Partnership convened and supported a community of practice to learn more about how to enable better CS teaching for emergent bilinguals. These are materials from from the PLC for a Design Journal to act as a planing template for teachers.Sponsored by the National Science Foundation under NSF grant CNS-1738645 and DRL-1837446. Any opinions, findings, and conclusions or recommendations expressed in this material are those of the author(s) and do not necessarily reflect the views of the National Science Foundation
Arizona Then and Now: Exploring Arizona's Five Cs Through Photography
No full textabstract: Arizona Then and Now: Exploring Arizona's Five Cs Through Photography is a photographic exploration of the evolution of Arizona's five Cs: cotton, copper, citrus, cattle, and climate. This project first looks to the past to see how these five elements shaped the state of Arizona. Photographs were taken across the valley of these elements, or lack thereof, discovering what Arizona has transformed into in the process. Each chapter of the book begins with a brief history of the element focused on in that chapter, followed by an analytical thought about the photographs taken and how the element has evolved. Each chapter shows two historical photographs followed by a series of photographs taken during the project that the author thought depicted what is seen today. The book ends on a final positive note about how the five Cs are not dead, but soon could be completely taken over. This project was a way for a non-art major to explore the state that she grew up while also challenging herself by more than just taking pictures. The photographs displayed in the book depict a sampling of what the author saw that is left of the five Cs
IR-improved DGLAP-CS QCD parton showers in Pythia8
No full textAbstractWe introduce the recently developed IR-improved DGLAP-CS theory into the showers in Pythia8, as this Monte Carlo event generator is in wide use at LHC. We show that, just as it was true in the IR-improved shower Monte Carlo Herwiri, which realizes the IR-improved DGLAP-CS theory in the Herwig6.5 environment, the soft limit in processes such as single heavy gauge boson production is now more physical in the IR-improved DGLAP-CS theory version of Pythia8. This opens the way to one’s getting a comparison between the actual detector simulations for some of the LHC experiments between IR-improved and unimproved showers as Pythia8 is used in detector simulations at LHC whereas Herwig6.5, the environment of the only other IR-improved DGLAP-CS QCD MC in the literature, Herwiri1.031, is not any longer so used. Our achieving the availability of the IR-improved DGLAP-CS Pythia8 then is an important step in the further development of the LHC precision theory program under development by the author and his collaborators
- …
