Anisotropic linear and non-linear excitonic optical properties of buckled monolayer semiconductors

The optical properties of two-dimensional materials are exceptional in several respects. They are highly anisotropic and frequently dominated by excitonic effects. Dipole-allowed second order non-linear optical properties require broken inversion symmetry. Hence, several two-dimensional materials show strong in-plane (IP) non-linearity but negligible out-of-plane (OOP) response due to vertical symmetry. By considering buckled hexagonal monolayers, we analyze the critical role of broken vertical symmetry on their excitonic optical response. Both linear as well as second order shift current and second harmonic response are studied. We demonstrate that substantial OOP non-linear response can be obtained, in particular, through off-diagonal tensor elements coupling IP excitation to OOP response. Our findings are explained by excitonic selection rules for OOP response and the impact of dielectric screening on excitons is elucidated.Comment: 20 pages, 8 figure

Object-oriented implementations of the MPDATA advection equation solver in C++, Python and Fortran

Three object-oriented implementations of a prototype solver of the advection equation are introduced. The presented programs are based on Blitz++ (C++), NumPy (Python), and Fortran's built-in array containers. The solvers include an implementation of the Multidimensional Positive-Definite Advective Transport Algorithm (MPDATA). The introduced codes exemplify how the application of object-oriented programming (OOP) techniques allows to reproduce the mathematical notation used in the literature within the program code. A discussion on the tradeoffs of the programming language choice is presented. The main angles of comparison are code brevity and syntax clarity (and hence maintainability and auditability) as well as performance. In the case of Python, a significant performance gain is observed when switching from the standard interpreter (CPython) to the PyPy implementation of Python. Entire source code of all three implementations is embedded in the text and is licensed under the terms of the GNU GPL license

Engineering Automation for Reliable Software Interim Progress Report (10/01/2000 - 09/30/2001)

Prepared for: U.S. Army Research Office P.O. Box 12211 Research Triangle Park, NC 27709-2211The objective of our effort is to develop a scientific basis for producing reliable software that is also flexible and cost effective for the DoD distributed software domain. This objective addresses the long term goals of increasing the quality of service provided by complex systems while reducing development risks, costs, and time. Our work focuses on "wrap and glue" technology based on a domain specific distributed prototype model. The key to making the proposed approach reliable, flexible, and cost-effective is the automatic generation of glue and wrappers based on a designer's specification. The "wrap and glue" approach allows system designers to concentrate on the difficult interoperability problems and defines solutions in terms of deeper and more difficult interoperability issues, while freeing designers from implementation details. Specific research areas for the proposed effort include technology enabling rapid prototyping, inference for design checking, automatic program generation, distributed real-time scheduling, wrapper and glue technology, and reliability assessment and improvement. The proposed technology will be integrated with past research results to enable a quantum leap forward in the state of the art for rapid prototyping.U. S. Army Research Office P.O. Box 12211 Research Triangle Park, NC 27709-22110473-MA-SPApproved for public release; distribution is unlimited

Arrow: A Modern Reversible Programming Language

Reversible programming languages are those whose programs can be run backwards as well as forwards. This condition impacts even the most basic constructs, such as =, if and while. I discuss Janus, the first imperative reversible programming language, and its limitations. I then introduce Arrow, a reversible language with modern features, including functions. Example programs are provided

Arrow: A Modern Reversible Programming Language

Reversible programming languages are those whose programs can be run backwards as well as forwards. This condition impacts even the most basic constructs, such as =, if and while. I discuss Janus, the first imperative reversible programming language, and its limitations. I then introduce Arrow, a reversible language with modern features, including functions. Example programs are provided

Exploring Estonian e-government before, during, and beyond COVID-19

The outbreak of COVID-19 saw lockdowns imposed across the world, and traditionally in-person tasks and services shifted online. While this posed immense challenges in some governmental and institutional settings, in Estonia rigorous digital advancements dating back to the 1990s have made this learning curve markedly less steep, as many digital service provisions were widely available prior to the pandemic. This paper explores Estonia’s e-government solutions pre-dating, during, and beyond the pandemic. It will examine mechanisms – e-ID, X-Road, the information authority, state portal, and e-learning – that existed prior to the pandemic, and others – new e-services, fully online learning, and contact tracing applications – that have emerged in direct response to the pandemic. Finally, this paper will examine how elements of Estonian e-government can, and have been, adopted in international settings, considering how cybersecurity, regulation, and accessibility are closely intertwined with such dialogues surrounding e-government

Proceedings of Monterey Workshop 2001 Engineering Automation for Sofware Intensive System Integration

The 2001 Monterey Workshop on Engineering Automation for Software Intensive System Integration was sponsored by the Office of Naval Research, Air Force Office of Scientific Research, Army Research Office and the Defense Advance Research Projects Agency. It is our pleasure to thank the workshop advisory and sponsors for their vision of a principled engineering solution for software and for their many-year tireless effort in supporting a series of workshops to bring everyone together.This workshop is the 8 in a series of International workshops. The workshop was held in Monterey Beach Hotel, Monterey, California during June 18-22, 2001. The general theme of the workshop has been to present and discuss research works that aims at increasing the practical impact of formal methods for software and systems engineering. The particular focus of this workshop was "Engineering Automation for Software Intensive System Integration". Previous workshops have been focused on issues including, "Real-time & Concurrent Systems", "Software Merging and Slicing", "Software Evolution", "Software Architecture", "Requirements Targeting Software" and "Modeling Software System Structures in a fastly moving scenario".Office of Naval ResearchAir Force Office of Scientific Research Army Research OfficeDefense Advanced Research Projects AgencyApproved for public release, distribution unlimite

System engineering and evolution decision support, Final Progress Report (05/01/1998 - 09-30-2001)

The objective of our effort is to develop a scientific basis for system engineering automation and decision support. This objective addresses the long term goals of increasing the quality of service provided complex systems while reducing development risks, costs, and time. Our work focused on decision support for designing operations of complex modular systems that can include embedded software. Emphasis areas included engineering automation capabilities in the areas of design modifications, design records, reuse, and automatic generation of design representations such as real-time schedules and software.U.S. Army Research OfficeFunding number(s): DSAM 90387, DWAM 80013, DWAM 90215

Austerity, Competitiveness and Neoliberalism Redux: Ontario Responds to the Great Recession

This article examines the deepening integration of market imperatives throughout the province of Ontario. We do this by, first, examining neoliberalism’s theoretical underpinnings, second, reviewing Ontario’s historical context, and third, scrutinizing the Open Ontario Plan, with a focus on proposed changes to employment standards legislation. We argue that contrary to claims of shared restraint and the pressing need for public austerity, Premier McGuinty’s Liberal’s have re-branded and re-packaged core neoliberal policies in such a manner that costs are socialized and profits privatized, thereby intensifying class polarization along with its racialized and gendered diversities. Cet article analyse l’intégration de plus en plus profonde des impératifs du marché dans la province de l’Ontario. Nous faisons cette analyse, premièrement, en analysant les bases théoriques du néolibéralisme, deuxièmement, en décrivant le contexte historique de l’Ontario, et troisièmement, en examinant le “Open Ontario Plan”, sous l’angle particulier des propositions de changement de la législation sur le droit du travail. Nous soutenons que sous le couvert de discours prônant le partage de l’austérité et l’impérieuse nécessité de restreindre les dépenses publiques, les Libéraux du Premier McGuinty ont ré-étiqueté et reformulé les politiques néolibérales de façon que les coûts soient socialisés et les profits privatisés, aggravant ainsi la polarisation des classes ainsi que les inégalités liées à la race et au genre