741 research outputs found
Performance Debugging and Tuning using an Instruction-Set Simulator
Instruction-set simulators allow programmers a detailed level of insight into,
and control over, the execution of a program, including parallel programs and
operating systems. In principle, instruction set simulation can model any
target computer and gather any statistic. Furthermore, such simulators are
usually portable, independent of compiler tools, and deterministic-allowing
bugs to be recreated or measurements repeated. Though often viewed as being
too slow for use as a general programming tool, in the last several years
their performance has improved considerably.
We describe SIMICS, an instruction set simulator of SPARC-based
multiprocessors developed at SICS, in its rĂŽle as a general programming tool.
We discuss some of the benefits of using a tool such as SIMICS to support
various tasks in software engineering, including debugging, testing, analysis,
and performance tuning. We present in some detail two test cases, where we've
used SimICS to support analysis and performance tuning of two applications,
Penny and EQNTOTT. This work resulted in improved parallelism in, and
understanding of, Penny, as well as a performance improvement for EQNTOTT of
over a magnitude. We also present some early work on analyzing SPARC/Linux,
demonstrating the ability of tools like SimICS to analyze operating systems
Partial Translation
Traditional simulation of a target architecture by interpreting
object code can be improved by translating the object code to an
intermediate format. This approach is called interpretive
translation. Despite a substantial performance improvement over
traditional interpretation, a large part of the overhead is
unnecessary. An alternative approach is block translation, where one
or more simulated instructions are translated to directly executable
code. This approach has several drawbacks.
We discuss the problems with block translation, analyse the overhead
of interpretive translation, and describe a hybrid approach-partial
translation-that combines the benefits of both approaches. Partial
translation implements an intermediate format that supports the
addition of run-time generated code whenever appropriate. The perfor-
mance limit (slowdown) of interpetive translation is around 15, and
real implementations have achieved 20-30. Partial translation will
perform considerably better. Finally, we present results from an
aggressive implementation of interpretive translation, and results
from a proof-of-concept implementation of partial translation
Online encoder-decoder anomaly detection using encoder-decoder architecture with novel self-configuring neural networks & pure linear genetic programming for embedded systems
Recent anomaly detection techniques focus on the use of neural networks and an encoder-decoder architecture. However, these techniques lead to trade offs if implemented in an embedded environment such as high heat management, power consumption and hardware costs. This paper presents two related new methods for anomaly detection within data sets gathered from an autonomous mini-vehicle with a CAN bus. The first method which to the best of our knowledge is the first use of encoder-decoder architecture for anomaly detection using linear genetic programming (LGP). Second method uses self-configuring neural network that is created using evolutionary algorithm paradigm learning both architecture and weights suitable for embedded systems. Both approaches have the following advantages: it is inexpensive regarding resource use, can be run on almost any embedded board due to linear register machine advantages in computation. The proposed methods are also faster by at least one order of magnitude, and it includes both inference and complete training
Load magnitude affects patellar tendon mechanical properties but not collagen or collagen cross-linking after long-term strength training in older adults
Abstract Background Regular loading of tendons may counteract the negative effects of aging. However, the influence of strength training loading magnitude on tendon mechanical properties and its relation to matrix collagen content and collagen cross-linking is sparsely described in older adults. The purpose of the present study was to compare the effects of moderate or high load resistance training on tendon matrix and its mechanical properties. Methods Seventeen women and 19 men, age 62â70âyears, were recruited and randomly allocated to 12âmonths of heavy load resistance training (HRT), moderate load resistance training (MRT) or control (CON). Pre- and post-intervention testing comprised isometric quadriceps strength test (IsoMVC), ultrasound based testing of in vivo patellar tendon (PT) mechanical properties, MRI-based measurement of PT cross-sectional area (CSA), PT biopsies for assessment of fibril morphology, collagen content, enzymatic cross-links, and tendon fluorescence as a measure of advanced glycation end-products (AGEs). Results Thirty three participants completed the intervention and were included in the data analysis. IsoMVC increased more after HRT (+â21%) than MRT (+â8%) and CON (+â7%) (pâ<â0.05). Tendon stiffness (pâ<â0.05) and Youngâs modulus (pâ=â0.05) were also differently affected by training load with a reduction in CON and MRT but not in HRT. PT-CSA increased equally after both MRT and HRT. Collagen content, fibril morphology, enzymatic cross-links, and tendon fluorescence were unaffected by training. Conclusion Despite equal improvements in tendon size after moderate and heavy load resistance training, only heavy. load training seemed to maintain tendon mechanical properties in old age. The effect of load magnitude on tendon biomechanics was unrelated to changes of major load bearing matrix components in the tendon core. The study is a sub-study of the LISA study, which was registered at http://clinicaltrials.gov (NCT02123641) April 25th 2014
Shoulder rotational strength profiles of danish national level badminton players
Background
Increased age has been shown to be associated with weaker external rotators and stronger internal rotators of the shoulder in pitchers and tennis players. Whether this age-associated change is present in elite badminton players is unknown.
Purpose
To compare the internal and external rotation strength of the shoulder in adolescent and adult elite badminton players.
Study design
Cross-sectional.
Methods
Thirty-one adolescent (12 females aged 16.8 ± 1.6 years and 19 males aged 17.1 ± 1.6 years) and 29 adult (10 females aged 25 ± 2.9 years and 19 males aged 26.2 ± 4.6 years) national level badminton players were tested pre-seasonally for external rotation (ER) and internal rotation (IR) isometric muscle strength bilaterally, using a hand-held dynamometer. Within-group ER to IR strength ratios were calculated (ER/IRĂ100%).
Results
The adolescents had stronger shoulder ER than the adults on both sides (p < 0.05). The adult males tended to have stronger IR of the dominant shoulder than the adolescent males (p = 0.071). In the dominant shoulders, the strength ratios for adult females and males were 77% and 78%, respectively, while the same ratio for adolescent females and males were 85% and 99%, respectively. In the non-dominant shoulders, the ER/IR strength ratios for adult females and males were 90% and 87%, respectively, while the ratios for adolescent females and males were 116% and 102%, respectively.
Conclusion
This study is the first to demonstrate that in shoulder injury-free national team badminton players, adolescents have stronger shoulder ER than adults on both sides. Therefore, increased age appears to be associated with weaker shoulder ER muscles in elite badminton players.publishedVersio
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