552 research outputs found
Energyware engineering: techniques and tools for green software development
Tese de Doutoramento em Informática (MAP-i)Energy consumption is nowadays one of the most important concerns worldwide. While
hardware is generally seen as the main culprit for a computer’s energy usage, software
too has a tremendous impact on the energy spent, as it can cancel the efficiency introduced
by the hardware. Green Computing is not a newfield of study, but the focus has been,
until recently, on hardware. While there has been advancements in Green Software techniques,
there is still not enough support for software developers so they can make their
code more energy-aware, with various studies arguing there is both a lack of knowledge
and lack of tools for energy-aware development.
This thesis intends to tackle these two problems and aims at further pushing
forward research on Green Software. This software energy consumption issue is faced
as a software engineering question. By using systematic, disciplined, and quantifiable
approaches to the development, operation, and maintenance of software we defined several
techniques, methodologies, and tools within this document. These focus on providing
software developers more knowledge and tools to help with energy-aware software
development, or Energyware Engineering.
Insights are provided on the energy influence of several stages performed during
a software’s development process. We look at the energy efficiency of various popular
programming languages, understanding which are the most appropriate if a developer’s
concern is energy consumption. A detailed study on the energy profiles of different
Java data structures is also presented, alongwith a technique and tool, further providing
more knowledge on what energy efficient alternatives a developer has to choose from. To
help developers with the lack of tools, we defined and implemented a technique to detect
energy inefficient fragments within the source code of a software system. This technique
and tool has been shown to help developers improve the energy efficiency of their programs,
and even outperforming a runtime profiler. Finally, answers are provided to common questions and misconceptions within
this field of research, such as the relationship between time and energy, and howone can
improve their software’s energy consumption.
This thesis provides a great effort to help support both research and education on
this topic, helps continue to grow green software out of its infancy, and contributes to
solving the lack of knowledge and tools which exist for Energyware Engineering.Hoje em dia o consumo energĂ©tico Ă© uma das maiores preocupações a nĂvel global. Apesar
do hardware ser, de umaforma geral, o principal culpado para o consumo de energia
num computador, o software tem também um impacto significativo na energia consumida,
pois pode anular, em parte, a eficiĂŞncia introduzida pelo hardware. Embora
Green Computing não seja uma área de investigação nova, o foco tem sido, até recentemente,
na componente de hardware. Embora as técnicas de Green Software tenham
vindo a evoluir, não há ainda suporte suficiente para que os programadores possam
produzir código com consciencialização energética. De facto existemvários estudos que
defendem que existe tanto uma falta de conhecimento como uma escassez de ferramentas
para o desenvolvimento energeticamente consciente.
Esta tese pretende abordar estes dois problemas e tem como foco promover avanços
em green software. O tĂłpico do consumo de energia Ă© abordado duma perspectiva
de engenharia de software. Através do uso de abordagens sistemáticas, disciplinadas
e quantificáveis no processo de desenvolvimento, operação e manutencão de software,
foi possĂvel a definição de novas metodologias e ferramentas, apresentadas neste documento.
Estas ferramentas e metodologias tĂŞm como foco dotar de conhecimento e
ferramentas os programadores de software, de modo a suportar um desenvolvimento
energeticamente consciente, ou Energyware Engineering.
Deste trabalho resulta a compreensão sobre a influência energética a ser usada
durante as diferentes fases do processo de desenvolvimento de software. Observamos as
linguagens de programação mais populares sobre um ponto de vista de eficiência energética,
percebendo quais as mais apropriadas caso o programador tenha uma preocupação
com o consumo energético. Apresentamos também um estudo detalhado sobre perfis energéticos de diferentes
estruturas de dados em Java, acompanhado por técnicas e ferramentas, fornecendo
conhecimento relativo a quais as alternativas energeticamente eficientes que os programadores
dispõem. Por forma a ajudar os programadores, definimos e implementamos
uma técnica para detetar fragmentos energicamente ineficientes dentro do código fonte
de um sistema de software. Esta técnica e ferramenta têm demonstrado ajudar programadores
a melhorarem a eficiência energética dos seus programas e em algum casos
superando um runtime profiler.
Por fim, são dadas respostas a questões e conceções erradamente formuladas dentro
desta área de investigação, tais como o relacionamento entre tempo e energia e como
Ă© possĂvel melhorar o consumo de energia do software.
Foi empregue nesta tese um esforço árduo de suporte tanto na investigação como
na educação relativo a este tópico, ajudando à maturação e crescimento de green computing,
contribuindo para a resolução da lacuna de conhecimento e ferramentas para
suporte a Energyware Engineering.This work is partially funded by FCT – Foundation for Science and Technology, the
Portuguese Ministry of Science, Technology and Higher Education, through national funds,
and co-financed by the European Social Fund (ESF) through the Operacional Programme for
Human Capital (POCH), with scholarship reference SFRH/BD/112733/2015. Additionally,
funding was also provided the ERDF – European Regional Development Fund – through
the Operational Programmes for Competitiveness and Internationalisation COMPETE and
COMPETE 2020, and by the Portuguese Government through FCT project Green Software
Lab (ref. POCI-01-0145-FEDER-016718), by the project GreenSSCM - Green Software for
Space Missions Control, a project financed by the Innovation Agency, SA, Northern Regional
Operational Programme, Financial Incentive Grant Agreement under the Incentive Research
and Development System, Project No. 38973, and by the Luso-American Foundation in
collaboration with the National Science Foundation with grant FLAD/NSF ref. 300/2015 and
ref. 275/2016
Compiling Tree Transforms to Operate on Packed Representations
When written idiomatically in most programming languages, programs
that traverse and construct trees operate over pointer-based data
structures, using one heap object per-leaf and per-node. This
representation is efficient for random access and shape-changing
modifications, but for traversals, such as compiler passes, that
process most or all of a tree in bulk, it can be inefficient. In this
work we instead compile tree traversals to operate on
pointer-free pre-order serializations of trees. On modern
architectures such programs often run significantly faster than
their pointer-based counterparts, and additionally are directly suited
to storage and transmission without requiring marshaling.
We present a prototype compiler, Gibbon, that compiles a
small first-order, purely functional language sufficient for tree
traversals. The compiler transforms this language into intermediate
representation with explicit pointers into input and output buffers
for packed data. The key compiler technologies include an effect
system for capturing traversal behavior, combined with an algorithm to
insert destination cursors. We evaluate our compiler on tree
transformations over a real-world dataset of source-code syntax trees.
For traversals touching the whole tree, such as maps and folds, packed
data allows speedups of over 2x compared to a highly-optimized
pointer-based baseline
The Role of Padel in Improving Physical Fitness and Health Promotion: Progress, Limitations, and Future Perspectives—A Narrative Review
Benefits of regular exercise for health are beyond any doubt. However, adherence to regular
physical activity is an ongoing challenge. Among the options for exercise engagement, racket sports,
and particularly padel, stand as emerging practices for children and adults to have fun, improve
physical fitness, and potentially develop motor and cognitive skills. In the last decade, the literature
on padel is increasing exponentially. However, there is a need for further experimental research. To
design safe and effective sport-base physical activity promotion interventions, it is essential to have a
deep understanding of the physical requirements, technical complexity, injury risks, and strength
and conditioning programs. To assist researchers to conduct effective padel-based interventions for
health, this review summarizes the state-of-the-art evidence about padel, identifies key topics to be
addressed in the future, and discusses the potential role of padel as a physical fitness and health
promotion strategy. A narrative review is presented, summarizing the results of padel articles from
three different databases: Web of Science, Scopus, and Google Scholar. Studies written in Spanish
and English were the inclusion criteria. The studies had to be published from 2000 onwards and be
original, as well as peer-reviewed
Transient Typechecks are (Almost) Free
Transient gradual typing imposes run-time type tests that typically cause a linear slowdown in
programs’ performance. This performance impact discourages the use of type annotations because
adding types to a program makes the program slower. A virtual machine can employ standard justin-time optimizations to reduce the overhead of transient checks to near zero. These optimizations
can give gradually-typed languages performance comparable to state-of-the-art dynamic languages,
so programmers can add types to their code without affecting their programs’ performance
Optimizing Abstract Abstract Machines
The technique of abstracting abstract machines (AAM) provides a systematic
approach for deriving computable approximations of evaluators that are easily
proved sound. This article contributes a complementary step-by-step process for
subsequently going from a naive analyzer derived under the AAM approach, to an
efficient and correct implementation. The end result of the process is a two to
three order-of-magnitude improvement over the systematically derived analyzer,
making it competitive with hand-optimized implementations that compute
fundamentally less precise results.Comment: Proceedings of the International Conference on Functional Programming
2013 (ICFP 2013). Boston, Massachusetts. September, 201
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