1,903 research outputs found
The Sparse Abstract Machine
We propose the Sparse Abstract Machine (SAM), an abstract machine model for
targeting sparse tensor algebra to reconfigurable and fixed-function spatial
dataflow accelerators. SAM defines a streaming dataflow abstraction with sparse
primitives that encompass a large space of scheduled tensor algebra
expressions. SAM dataflow graphs naturally separate tensor formats from
algorithms and are expressive enough to incorporate arbitrary iteration
orderings and many hardware-specific optimizations. We also present Custard, a
compiler from a high-level language to SAM that demonstrates SAM's usefulness
as an intermediate representation. We automatically bind from SAM to a
streaming dataflow simulator. We evaluate the generality and extensibility of
SAM, explore the performance space of sparse tensor algebra optimizations using
SAM, and show SAM's ability to represent dataflow hardware.Comment: 18 pages, 17 figures, 3 table
Bridging Two Worlds
The rise of China and India could be the most important political development of the twenty-first century. What will the foreign policies of China and India look like in the future? What should they look like? And what can each country learn from the other? Bridging Two Worlds gathers a coterie of experts in the field, analyzing profound political thinkers from these ancient regions whose theories of interstate relations set the terms for the debates today. This volume is the first work of its kind and is essential reading for anyone interested in the growth of China and India and what it means for the rest of the world.
“This brilliant volume shines a light on the two great civilizations that will once again drive world history. No volume could be more timely, more relevant, and more needed than this one.” — KISHORE MAHBUBANI, Distinguished Fellow, Asia Research Institute, NUS, and author of The Asian 21st Century
“With the recently elevated economic and political power of China and the great potential of India in the twenty-first century, interdisciplinary dialogue and engagement such as is found in this book is necessary for contemporary debates in political theory and international relations.” — KUIYI SHEN, Professor of Asian Art History, Theory, and Criticism, University of California, San Diego
Adding hygiene to gambit scheme
Le langage de programmation Scheme est reconnu pour son puissant
système de macro-transformations. La représentation
du code source d'un programme, sous forme de données manipulables
par le langage,
permet aux programmeurs de modifier directement
l'arbre de syntaxe abstraite sous-jacent.
Les macro-transformations
utilisent une syntaxe similaire aux procédures régulières mais,
elles définissent plutôt des procédures à exécuter
lors de la phase de compilation.
Ces procédures retournent une représentation sous
forme d'arbre de syntaxe abstraite qui devra être substitué
à l'emplacement de l'appel du transformateur. Les procédures
exécutées durant la phase de compilation profitent
de la même puissance que celles exécutées durant de la phase d'évaluation.
Avec ce genre de système de macro-transformations,
un programmeur peut créer des règles de syntaxe spécialisées
sans aucun coût additionnel en performance:
ces extensions syntactiques
permettent l'abstraction de code sans les coûts d'exécution
habituels reliés à la création d'une fermeture sur le tas.
Cette représentation pour le code source de Scheme provient
directement du langage de programmation Lisp. Le code source
est représenté sous forme de listes manipulables
de symboles, ou bien de
listes contenants d'autres listes: une structure appelée
S-expression. Cependant, avec cette approche simpliste,
des conflits de noms peuvent apparaître.
En effet, l'association référée par un certain identifiant
est déterminée exclusivement par
le contexte lexical de celui-ci.
En déplaçant un identifiant dans l'arbre de syntaxe abstraite,
il est possible que cet identifiant se retrouve dans
un contexte lexical contenant une certaine association pour un identifiant du mĂŞme nom.
Dans de tels cas,
l'identifiant déplacé pourrait ne plus référer à l'association
attendue, puisque cette seconde
association pourrait avoir prévalence sur
la première. L'assurance de transparence référentielle est alors perdue.
En conséquence, le choix de nom pour les identifiants
vient maintenant influencer directement
le comportement du programme,
générant des erreurs difficiles à comprendre.
Les conflits de noms
peuvent être corrigés manuellement dans le code en utilisant,
par exemple, des noms d'identifiants uniques.
La préservation automatique de la transparence référentielle
se nomme hygiène, une notion qui a été beaucoup
étudiée dans le contexte
des langages de la famille Lisp.
La dernière version du Scheme revised report, utilisée
comme spécification pour le langage, étend ce dernier
avec un support pour les macro-transformations hygiéniques.
Jusqu'Ă maintenant,
l'implémentation Gambit de Scheme ne fournissait
pas de tel système à sa base. Comme contribution, nous
avons ré-implémenter le système de macro de Gambit pour
supporter les macro-transformations hygiéniques au plus bas niveau
de l'implémentation. L'algorithme choisi se base sur l'algorithme
set of scopes implémenté dans le langage Racket et créé par Matthew Flatt.
Le langage Racket s'est grandement inspiré
du langage Scheme mais, diverge
sur plusieurs fonctionnalités importantes. L'une de
ces différences est le puissant système de macro-transformation
sur lequel Racket base la majorité de ses primitives.
Dans ce contexte, l'algorithme a donc été testé
de façon robuste.
Dans cette thèse, nous donnerons un aperçu du langage
Scheme et de sa syntaxe. Nous énoncerons le problème d'hygiène
et décrirons différentes stratégies utilisées
pour le résoudre. Nous justifierons par la suite
notre choix d'algorithme et fourniront une définition
formelle. Finalement, nous présenterons une analyse
de la validité et de la performance du compilateur en
comparant la version originale de Gambit avec notre
version supportant l'hygiène.The Scheme programming language is known for
its powerful macro system.
With Scheme source code represented as actual Scheme data,
macro transformations
allow the programmer, using that data, to act directly on the
underlying abstract syntax tree.
Macro transformations use a similar syntax to
regular procedures but, they define procedures
meant to be executed at compile time.
Those procedures return an abstract syntax tree representation
to be substituted at the transformer's call location.
Procedures executed at compile-time use the same
language power as run-time procedures.
With the macro system,
the programmer can create specialized
syntax rules without additional performance costs.
This also allows for code abstractions
without the expected run-time cost of closure creations.
Scheme's representation of source code using values
inherits that virtue from the Lisp programming language.
Source code is represented as a list of symbols, or lists
of other lists: a structure coined S-expressions.
However, with this simplistic approach,
accidental name clashes can occur.
The binding to which an identifier refers to
is determined by the lexical context of that identifier.
By moving an identifier around in the abstract syntax tree,
it can be caught within the lexical context of another binding definition with the same name.
This can cause unexpected behavior for programmers
as the choice of names can create substantial changes
in the program.
Accidental name clashes can be manually fixed in the code,
using name obfuscation, for instance.
However, the programmer becomes responsible
for the program's safety.
The automatic preservation of referential transparency
is called hygiene and was
thoroughly studied in the context
of lambda calculus and Lisp-like languages.
The latest Scheme revised report, used as a specification for the
language, extend the language with hygienic macro
transformations.
Up to this point, the Gambit Scheme implementation
wasn't providing a built-in hygienic macro system.
As a contribution, we re-implemented Gambit's
macro system to support hygienic transformations
at its core.
The algorithm we chose is
based on the set of scopes algorithm, implemented in the
Racket language by Matthew Flatt.
The Racket language is heavily based on Scheme but,
diverges on some core features.
One key aspect of the Racket language is
its extensive hygienic syntactic macro system, on
which most core features are built on:
the algorithm
was robustly tested in that context.
In this thesis, we will give an overview of the Scheme language
and its syntax. We will state the hygiene problem and describe
different strategies used to enforce hygiene automatically.
Our algorithmic
choice is then justified and formalized. Finally, we
present the original Gambit macro system and explain
the changes required. We also provide a validity and performance
analysis, comparing the original Gambit implementation to
our new system
SPEC5G: A Dataset for 5G Cellular Network Protocol Analysis
5G is the 5th generation cellular network protocol. It is the
state-of-the-art global wireless standard that enables an advanced kind of
network designed to connect virtually everyone and everything with increased
speed and reduced latency. Therefore, its development, analysis, and security
are critical. However, all approaches to the 5G protocol development and
security analysis, e.g., property extraction, protocol summarization, and
semantic analysis of the protocol specifications and implementations are
completely manual. To reduce such manual effort, in this paper, we curate
SPEC5G the first-ever public 5G dataset for NLP research. The dataset contains
3,547,586 sentences with 134M words, from 13094 cellular network specifications
and 13 online websites. By leveraging large-scale pre-trained language models
that have achieved state-of-the-art results on NLP tasks, we use this dataset
for security-related text classification and summarization. Security-related
text classification can be used to extract relevant security-related properties
for protocol testing. On the other hand, summarization can help developers and
practitioners understand the high level of the protocol, which is itself a
daunting task. Our results show the value of our 5G-centric dataset in 5G
protocol analysis automation. We believe that SPEC5G will enable a new research
direction into automatic analyses for the 5G cellular network protocol and
numerous related downstream tasks. Our data and code are publicly available
Employee Engagement and Leadership in the Federal Sector
While levels of engagement have slightly increased, employee engagement in the U.S. federal government sector still significantly lags when compared to the private sector. When asked if organizational leaders generate high levels of motivation and commitment in the workforce, only 48% of U.S. federal government employees indicated a positive response. The purpose of this quantitative correlation study and primary research question was to determine to what extent, if any, does a relationship exist between perceptions of leadership communication and effectiveness and employee engagement in the U.S. federal government sector. The theoretical framework of this quantitative correlational study was informed by William A. Kahn’s theory of personal engagement and the public service motivation theory. An online survey was employed, and a total of 139 participants were included in this study. To test the research hypothesis, a linear regression analysis was conducted. The findings suggest that there is a significant relationship between perceptions of leadership communication and effectiveness and levels of employee engagement; public service motivation and employee engagement; and trust in leadership and employee engagement in the U.S. federal government. These findings may help contribute to positive social change as improved engagement and leadership practices may enhance productivity and increase employee effectiveness in the federal workplace
Alexander Dallas Bache: Building the American Nation through Science and Education in the Nineteenth Century
Alexander Dallas Bache was the key leader of antebellum American scientists. Presuming his profession to be a herald of an integrated U.S. nation-state, Bache guided organizations such as the United States Coast Survey, then the country's largest scientific enterprise. In this analytical biography, Axel Jansen explains Bache's efforts to build and shape public institutions as a national foundation for a universalistic culture - efforts that culminated during the Civil War when Bache helped found the National Academy of Sciences as a symbol for the continued viability of an American nation
Operatic Pasticcios in 18th-Century Europe
In Early Modern times, techniques of assembling, compiling and arranging pre-existing material were part of the established working methods in many arts. In the world of 18th-century opera, such practices ensured that operas could become a commercial success because the substitution or compilation of arias fitting the singer's abilities proved the best recipe for fulfilling the expectations of audiences. Known as »pasticcios« since the 18th-century, these operas have long been considered inferior patchwork. The volume collects essays that reconsider the pasticcio, contextualize it, define its preconditions, look at its material aspects and uncover its aesthetical principles
Strategies Dental Center Leaders Use to Improve Productivity Using Onsite 3D Printing
Many dental centers are leveraging onsite 3D printing to increase their productivity and improve the quality of care they provide. However, dental center leaders lacking strategies to implement onsite 3D printing in their dental centers fail to take advantage of the substantial benefits of using this new technology. Grounded in the theory of disruptive innovation, the purpose of this qualitative multiple-case study was to explore strategies dental center leaders use to improve productivity using onsite 3D printing. The participants comprised five dental center leaders in the United States who successfully implemented strategies to improve productivity using onsite 3D printing. Data were collected from semistructured interviews, company websites, and publicly available information. Thematic analysis was used to analyze the data. Three themes emerged: (a) enabling technology strategy, (b) innovative business model strategy, and (c) customer demand strategy. A key recommendation includes ensuring better patient experiences with less chair time, fewer visits, and more access to care. The implications for positive social change have the potential to make affordable quality dental care available to underserved communities, facilitate new career opportunities for local communities, and contribute to the economic development of these communities
"Le present est plein de l’avenir, et chargé du passé" : Vorträge des XI. Internationalen Leibniz-Kongresses, 31. Juli – 4. August 2023, Leibniz Universität Hannover, Deutschland. Band 1
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