19,319 research outputs found
The effect of real workloads and stochastic workloads on the performance of allocation and scheduling algorithms in 2D mesh multicomputers
The performance of the existing non-contiguous processor allocation strategies has been traditionally carried out by means of simulation based on a stochastic workload model to generate a stream of incoming jobs. To validate the performance of the existing algorithms, there has been a need to evaluate the algorithms' performance based on a real workload trace. In this paper, we evaluate the performance of several well-known processor allocation and job scheduling strategies based on a real workload trace and compare the results against those obtained from using a stochastic workload. Our results reveal that the conclusions reached on the relative performance merits of the allocation strategies when a real workload trace is used are in general compatible with those obtained when a stochastic workload is used
Using Serious Games for Learning British Sign Language Combining Video, Enhanced Interactivity, and VR Technology
One in every six persons in the UK suffers a hearing loss, either as a condition they have been born with or they disordered they acquired during their life. 900,000 people in the UK are severely or profoundly deaf and based on a study by Action On Hearing Loss UK in 2013 only 17 percent of this population, can use the British Sign Language (BSL). That leaves a massive proportion of people with a hearing impediment who do not use sign language struggling in social interaction and suffering from emotional distress, and an even larger proportion of Hearing people who cannot communicate with those of the deaf community. This paper presents a serious game (SG) that aims to close the communication gap between able hearing people and people with a hearing impediment by providing a tool that facilitates BSL learning targeting adult population. The paper presents the theoretical framework supporting adult learning based on which a SG game using Virtual Reality (VR) technology has been developed. It explains the experimental framework of the study and presents the creation of the research instruments to facilitate the study comprising of a SG that integrates video and conventional video based educational material. It reports and analyses the study results that demonstrate the advantage of the SG in effectively supporting users learning a set of BSL signs and it presents qualitative outcomes that inform the further development of the game to serve learning needs. The paper closes with conclusions, directions for further development of this educational resource and future studies
Measurements of Far-UV Emission from Elliptical Galaxies at z=0.375
The ``UV upturn'' is a sharp rise in spectra of elliptical galaxies shortward
of rest-frame 2500 A. It is a ubiquitous phenomenon in nearby giant elliptical
galaxies, and is thought to arise primarily from low-mass evolved stars on the
extreme horizontal branch and beyond. Models suggest that the UV upturn is a
very strong function of age for these old stellar populations, increasing as
the galaxy gets older. In some models the change in UV/optical flux ratio is a
factor of 25 over timescales of less than 3 Gyr. To test the predictions for
rapid evolution of the UV upturn, we have observed a sample of normal
elliptical galaxies in the z=0.375 cluster Abell 370 with the Faint Object
Camera aboard the Hubble Space Telescope. A combination of two long-pass
filters was used to isolate wavelengths shortward of rest-frame 2700 A,
providing a measurement of the UV upturn at a lookback time of approximately 4
Gyr. Surprisingly, the four elliptical galaxies observed show a range of UV
upturn strength that is similar to that seen in nearby elliptical galaxies,
with an equivalent 1550-V color ranging from 2.9-3.4 mag. Our result is
inconsistent with some models for the UV upturn; other models are consistent
only for a high redshift of formation (z_f >= 4).Comment: 4 pages, Latex. 1 figure. To appear in ApJL. Uses emulateapj.sty and
apjfonts.sty. Revision includes minor ApJ edits & fixes typo
An Afro-Asian nexus: South African multinational firm experiences in Chinese labour markets - key focus areas
This exploratory study examines perspectives of multinational corporations (MNCs) from South Africa (SA) in respect of the variables considered important in product and labour markets in China. These include how MNCs first interpret and understand cultural, human capital, regulatory factors and employment practices, before considering how they might adapt to or seek to influence them. A survey of thirteen SA firms operating or trading in these markets and interviews with South Africans who had undertaken exploratory assignments in China, were done. Key factors were identified and evaluated based on relevant literature and research. The following six focus areas were found to be important for business effectiveness in this market: understanding its market complexity, importance of joint venture partners, guanxi relationship networks, human capital, language and culture, and regulatory environment
Task constraints distinguish perspective inferences from perspective use during discourse interpretation in a false belief task
Interpreting other peoplesâ actions relies on an understanding of their current mental states (e.g. beliefs, desires and intentions). In this paper, we distinguish between listenersâ ability to infer othersâ perspectives and their explicit use of this knowledge to predict subsequent actions. In a visual-world study, two groups of participants (passive observers vs. active participants) watched short videos, depicting transfer events, where one character (âJaneâ) either held a true or false belief about an objectâs location. We tracked participantsâ eye-movements around the final visual scene, time-locked to related auditory descriptions (e.g. âJane will look for the chocolates in the container on the leftâ.). Results showed that active participants had already inferred the characterâs belief in the 1 s preview period prior to auditory onset, before it was possible to use this information to predict an outcome. Moreover, they used this inference to correctly anticipate reference to the objectâs initial location on false belief trials at the earliest possible point (i.e. from âJaneâ onwards). In contrast, passive observers only showed evidence of a belief inference from the onset of âJaneâ, and did not show reliable use of this inference to predict Janeâs behaviour on false belief trials until much later, when the location (âleft/rightâ) was auditorily available. These results show that active engagement in a task activates earlier inferences about othersâ perspectives, and drives immediate use of this information to anticipate othersâ actions, compared to passive observers, who are susceptible to influences from egocentric or reality biases. Finally, we review evidence that using other peoplesâ perspectives to predict their behaviour is more cognitively effortful than simply using oneâs own
Field collection, preservation and large scale DNA extraction procedures for cassava (Manihot esculenta Crantz.)
Some genetic studies using molecular methods such as diversity assessment or marker-assisted selection require collection of a large number of samples from fields located in the vicinity or in remote areas, followed by isolation of good quality DNA in a short time span. In the present study, different tissue preservation methods were compared for subsequent DNA extraction using a modified CTAB method in two 96-well plates, following grinding of leaf tissues with a GenoGrinder 2000. We found that preservation of leaf tissues in NaCl-CTAB-azide buffer (as described in Rogstad, 1992) at 4°C is a better storage procedure than preservation at -20°C to obtain good quality DNA. Comparison of DNA extraction with or without use of phenol revealed that the quality of DNA was not drastically affected when non-phenol extraction protocol was used and did not affect PCR amplification. Thus, the recommended DNA extraction procedure allowed us to process 192 samples per day at a cost of $0.80 per sample, with an average yield of 1.8  g, suitable for both PCR and genotyping
Exploring More-Coherent Quantum Annealing
In the quest to reboot computing, quantum annealing (QA) is an interesting
candidate for a new capability. While it has not demonstrated an advantage over
classical computing on a real-world application, many important regions of the
QA design space have yet to be explored. In IARPA's Quantum Enhanced
Optimization (QEO) program, we have opened some new lines of inquiry to get to
the heart of QA, and are designing testbed superconducting circuits and
conducting key experiments. In this paper, we discuss recent experimental
progress related to one of the key design dimensions: qubit coherence. Using
MIT Lincoln Laboratory's qubit fabrication process and extending recent
progress in flux qubits, we are implementing and measuring QA-capable flux
qubits. Achieving high coherence in a QA context presents significant new
engineering challenges. We report on techniques and preliminary measurement
results addressing two of the challenges: crosstalk calibration and qubit
readout. This groundwork enables exploration of other promising features and
provides a path to understanding the physics and the viability of quantum
annealing as a computing resource.Comment: 7 pages, 3 figures. Accepted by the 2018 IEEE International
Conference on Rebooting Computing (ICRC
Adult Learning Sign Language by combining video, interactivity and play in a 3D game platform
One in every six persons in the UK suffers a hearing loss, either as a condition they have been born with or a disorder they acquired during their life. 900,000 people in the UK are severely or profoundly deaf and based on a study by Action On Hearing Loss UK in 2013 only 17 percent of this population, can use the British Sign Language (BSL). That leaves a massive proportion of people with a hearing impediment who do not use sign language struggling in social interaction and suffering from emotional distress, and an even larger proportion of Hearing people who cannot communicate with those of the deaf community. This paper presents a theoretical framework for the design of interactive games to support learning BSL supporting the entire learning cycle, instruction, practice and assessment. It then describes the proposed design of a game based on this framework aiming to close the communication gap between able hearing people and people with a hearing impediment, by providing a tool that facilitates BSL learning targeting adult population. The paper concludes with the planning of a large scale study and directions for further development of this educational resource
Halos of Spiral Galaxies. III. Metallicity Distributions
(Abriged) We report results of a campaign to image the stellar populations in
the halos of highly inclined spiral galaxies, with the fields roughly 10 kpc
(projected) from the nuclei. We use the F814W (I) and F606W (V) filters in the
Wide Field Planetary Camera 2, on board the Hubble Space telescope. Extended
halo populations are detected in all galaxies. The color-magnitude diagrams
appear to be completely dominated by giant-branch stars, with no evidence for
the presence of young stellar populations in any of the fields. We find that
the metallicity distribution functions are dominated by metal-rich populations,
with a tail extending toward the metal poor end. To first order, the overall
shapes of the metallicity distribution functions are similar to what is
predicted by simple, single-component model of chemical evolution with the
effective yields increasing with galaxy luminosity. However, metallicity
distributions significantly narrower than the simple model are observed for a
few of the most luminous galaxies in the sample. It appears clear that more
luminous spiral galaxies also have more metal-rich stellar halos. The
increasingly significant departures from the closed-box model for the more
luminous galaxies indicate that a parameter in addition to a single yield is
required to describe chemical evolution. This parameter, which could be related
to gas infall or outflow either in situ or in progenitor dwarf galaxies that
later merge to form the stellar halo, tends to act to make the metallicity
distributions narrower at high metallicity.Comment: 20 pages, 8 figures (ApJ, in press
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