1,810 research outputs found
A Domain Specific Approach to High Performance Heterogeneous Computing
Users of heterogeneous computing systems face two problems: firstly, in
understanding the trade-off relationships between the observable
characteristics of their applications, such as latency and quality of the
result, and secondly, how to exploit knowledge of these characteristics to
allocate work to distributed computing platforms efficiently. A domain specific
approach addresses both of these problems. By considering a subset of
operations or functions, models of the observable characteristics or domain
metrics may be formulated in advance, and populated at run-time for task
instances. These metric models can then be used to express the allocation of
work as a constrained integer program, which can be solved using heuristics,
machine learning or Mixed Integer Linear Programming (MILP) frameworks. These
claims are illustrated using the example domain of derivatives pricing in
computational finance, with the domain metrics of workload latency or makespan
and pricing accuracy. For a large, varied workload of 128 Black-Scholes and
Heston model-based option pricing tasks, running upon a diverse array of 16
Multicore CPUs, GPUs and FPGAs platforms, predictions made by models of both
the makespan and accuracy are generally within 10% of the run-time performance.
When these models are used as inputs to machine learning and MILP-based
workload allocation approaches, a latency improvement of up to 24 and 270 times
over the heuristic approach is seen.Comment: 14 pages, preprint draft, minor revisio
Seeing Shapes in Clouds: On the Performance-Cost trade-off for Heterogeneous Infrastructure-as-a-Service
In the near future FPGAs will be available by the hour, however this new
Infrastructure as a Service (IaaS) usage mode presents both an opportunity and
a challenge: The opportunity is that programmers can potentially trade
resources for performance on a much larger scale, for much shorter periods of
time than before. The challenge is in finding and traversing the trade-off for
heterogeneous IaaS that guarantees increased resources result in the greatest
possible increased performance. Such a trade-off is Pareto optimal. The Pareto
optimal trade-off for clusters of heterogeneous resources can be found by
solving multiple, multi-objective optimisation problems, resulting in an
optimal allocation of tasks to the available platforms. Solving these
optimisation programs can be done using simple heuristic approaches or formal
Mixed Integer Linear Programming (MILP) techniques. When pricing 128 financial
options using a Monte Carlo algorithm upon a heterogeneous cluster of Multicore
CPU, GPU and FPGA platforms, the MILP approach produces a trade-off that is up
to 110% faster than a heuristic approach, and over 50% cheaper. These results
suggest that high quality performance-resource trade-offs of heterogeneous IaaS
are best realised through a formal optimisation approach.Comment: Presented at Second International Workshop on FPGAs for Software
Programmers (FSP 2015) (arXiv:1508.06320
A High-Performance Triple Patterning Layout Decomposer with Balanced Density
Triple patterning lithography (TPL) has received more and more attentions
from industry as one of the leading candidate for 14nm/11nm nodes. In this
paper, we propose a high performance layout decomposer for TPL. Density
balancing is seamlessly integrated into all key steps in our TPL layout
decomposition, including density-balanced semi-definite programming (SDP),
density-based mapping, and density-balanced graph simplification. Our new TPL
decomposer can obtain high performance even compared to previous
state-of-the-art layout decomposers which are not balanced-density aware, e.g.,
by Yu et al. (ICCAD'11), Fang et al. (DAC'12), and Kuang et al. (DAC'13).
Furthermore, the balanced-density version of our decomposer can provide more
balanced density which leads to less edge placement error (EPE), while the
conflict and stitch numbers are still very comparable to our
non-balanced-density baseline
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Cognitive control for language switching in bilinguals: A quantitative meta-analysis of functional neuroimaging studies
In a quantitative meta-analysis, using the activation likelihood estimation method, we examined the neural regions involved in bilingual cognitive control, particularly when engaging in switching between languages. The purpose of this study was to evaluate the bilingual cognitive control model based on a qualitative analysis [Abutalebi, J., & Green, D. W. (2008). Control mechanisms in bilingual language production: Neural evidence from language switching studies. Language and Cognitive Processes, 23, 557-582.]. After reviewing 128 peer-reviewed articles, ten neuroimaging studies met our inclusion criteria and in each study, bilinguals switched between languages in response to cues. We isolated regions involved in voluntary language switching, by including reported contrasts between the switching conditions and high level baseline conditions involving similar tasks but requiring the use of only one language. Eight brain regions showed significant and reliable activation: left inferior frontal gyrus, left middle temporal gyrus, left middle frontal gyrus, right precentral gyrus, right superior temporal gyrus, midline pre-SMA and bilateral caudate nuclei. This quantitative result is consistent with bilingual aphasia studies that report switching deficits associated with lesions to the caudate nuclei or prefrontal cortex. It also extends the previously reported qualitative model. We discuss the implications of the findings for accounts of bilingual cognitive control
Strangers sharing space and lives : a qualitative study of the attitudes of single elderly persons living in shared accommodation in Hong Kong public housing estates = 「同居共住:長者對合住公共房屋的意見調查硏究」硏究報告
In response to the perceived housing needs of single elderly people, the Housing for Senior Citizens Scheme has been developed by the Hong Kong Housing Authority since the mid-1980s to provide shared housing for unrelated elderly people. Under this scheme, they live together in an apartment unit with individual bedrooms, but sharing certain facilities. This group is fairly numerous and, in Hong Kong in 1998, there were about 110,000 elderly people living alone for various reasons,among whom 34,000 were tenants in public housing estates. Despite some advantages, shared living for any age group can however lead to potential problems.
Using qualitative methodologies including focus groups and in-depth interviews, the research attempted to gain insights into the views of residents on the design and management of HSC projects, and their aspirations. Nine of the 38 HSC projects operating in 32 Hong Kong public housing estates in mid-1998 were studied. A total of 69 elderly participants (78% female, 22% male) attended the nine focus groups, each comprising 6 to 12 residents. Participants\u27 ages ranged from 62 to 90 years and their length of residence in an HSC from three months to 11 years.
To residents, positive features of the HSC projects included the provision of shelter in an elderly person\u27s later life, the care and attention of wardens and the installation of emergency alarms. Design and facility improvements in the newer housing estates appeared to serve better the needs of the residents, with enhanced privacy and reduction in shared facilities. However, older blocks still suffered from problems of insufficient maintenance and repair, and perceived high charges. Most residents appeared to have tried hard to adjust to group life but would prefer to have their own kitchen and bathroom. Conflicts sometimes arose from personality clashes, different cleaning and living habits, shared facilities and bills for water and repairs. Nevertheless, there were some residents who enjoyed the informal caring relationships and the feeling of security.
Another important feature found with respect to the elderly respondents was their low self-esteem and strong sense of powerlessness derived from their sharing of accommodation. Poor family relationships and previous living arrangements were also evident. The research suggests that integration of a caring role into housing provision is increasingly important. Autonomy in housing choice and in the management of life styles are also crucial given the diversity of personalities, needs and demands of the elderly population. The group living model should not be assumed to be a panacea for all single older persons in housing need
The international diffusion of expatriate dual citizenship
While the global increase of expatriate dual citizenship acceptance over the past decades has been widely observed, the temporal and spatial contexts of this trend have remained understudied. Based on a novel data set of expatriate dual citizenship policies worldwide since 1960, we find that dual citizenship toleration has increased in the last half century from one-third to three-quarter of states globally. We argue that these domestic policy changes should be understood in light of normative pressure in a world where restrictions on individual choice in citizenship status are increasingly contested and where liberalisation is reinforced through interdependence and diaspora politics. We apply Cox proportional hazard models to examine dual citizenship liberalisation and find that states are more likely to move to a tolerant policy if neighbouring states have done so and that they tend to do so in conjunction with extending voting rights to citizens residing abroad and receiving remittances from abroad. Contrary to other studies, we do not observe significant variation by regime type.publishedVersio
From Ise to the World in a Time of Pandemic
A collection of essays on COVID-19 by scholars from around the world who shared a common experience in Japan in the early stages of the pandemic, and then communicated from their respective countries as the disease spread around the world. Written in multiple styles and with diverse perspectives, these essays provide insight into the similarities and differences, and the equalizing and dis-equalizing aspects of the world’s response to the pandemic
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A single H/ACA small nucleolar RNA mediates tumor suppression downstream of oncogenic RAS.
Small nucleolar RNAs (snoRNAs) are a diverse group of non-coding RNAs that direct chemical modifications at specific residues on other RNA molecules, primarily on ribosomal RNA (rRNA). SnoRNAs are altered in several cancers; however, their role in cell homeostasis as well as in cellular transformation remains poorly explored. Here, we show that specific subsets of snoRNAs are differentially regulated during the earliest cellular response to oncogenic RASG12V expression. We describe a novel function for one H/ACA snoRNA, SNORA24, which guides two pseudouridine modifications within the small ribosomal subunit, in RAS-induced senescence in vivo. We find that in mouse models, loss of Snora24 cooperates with RASG12V to promote the development of liver cancer that closely resembles human steatohepatitic hepatocellular carcinoma (HCC). From a clinical perspective, we further show that human HCCs with low SNORA24 expression display increased lipid content and are associated with poor patient survival. We next asked whether ribosomes lacking SNORA24-guided pseudouridine modifications on 18S rRNA have alterations in their biophysical properties. Single-molecule Fluorescence Resonance Energy Transfer (FRET) analyses revealed that these ribosomes exhibit perturbations in aminoacyl-transfer RNA (aa-tRNA) selection and altered pre-translocation ribosome complex dynamics. Furthermore, we find that HCC cells lacking SNORA24-guided pseudouridine modifications have increased translational miscoding and stop codon readthrough frequencies. These findings highlight a role for specific snoRNAs in safeguarding against oncogenic insult and demonstrate a functional link between H/ACA snoRNAs regulated by RAS and the biophysical properties of ribosomes in cancer
BRCA1-IRIS Overexpression Promotes Formation of Aggressive Breast Cancers
Introduction: Women with HER2 + or triple negative/basal-like (TN/BL) breast cancers succumb to their cancer rapidly due, in part to acquired Herceptin resistance and lack of TN/BL-targeted therapies. BRCA1-IRIS is a recently discovered, 1399 residue, BRCA1 locus alternative product, which while sharing 1365 residues with the full-length product of this tumor suppressor gene, BRCA1/p220, it has oncoprotein-like properties. Here, we examine whether BRCA1-IRIS is a valuable treatment target for HER2 + and/or TN/BL tumors
Effect Of Combined Aerobic And Resistance Training On HPA Axis Reactivity In HIV+ Women Undergoing Treatment For Substance Abuse
Substance abuse and infection with human immunodeficiency virus (HIV) are chronic stressors that affect hypothalamic-pituitary-adrenal (HPA) axis function. The purpose of this study was to investigate the effect of combined aerobic and resistance training on HPA axis reactivity in women with HIV undergoing treatment for substance abuse. Sixteen women (mean ± SD; 41 ± 9 years, 164 ± 6 cm, 78.1 ± 17.1 kg, 36 ± 10 % body fat) infected with HIV and enrolled in an intensive 60-day in-patient substance addiction/abuse treatment program were recruited shortly after admission to the treatment facility. Participants were assigned to one of two groups using randomization: (1) supervised combined aerobic and resistance exercise sessions 3 times per week (EX) for six weeks or (2) no exercise training (Control) for six weeks. Before (PRE) and after (POST) the 6-week period participants completed a 10-min public speaking task (Trier Social Stress Test). Saliva samples were obtained before (baseline), immediately after, and every 10 min for 50 min after the task. Saliva samples were analyzed for cortisol. HPA axis reactivity was determined as the difference between the highest values after the test minus the baseline value. HPA axis reactivity did not differ between groups at PRE (EX: 1.9 ± 2.0 nmol•L-1; Control: 1.1 ± 2.7 nmol•L-1) or POST (EX: 1.7 ± 2.1 nmol•L-1; Control: 0.0 ± 1.3 nmol•L-1). Similarly no differences were found between PRE and POST although the reactivity for the Control group appeared to be reduced at POST. HIV+ women in early recovery from substance abuse appear to display blunted HPA axis reactivity. A combined aerobic and resistance training intervention did not affect this reactivity; although, the exercise intervention might have prevented a further decline in reactivity
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