1,518 research outputs found
Design and thermal modeling of a residential building
Thesis (S.B.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2009.Cataloged from PDF version of thesis.Includes bibliographical references (p. 37).Recent trends of green energy upgrade in commercial buildings show promise for application to residential houses as well, where there are potential energy-saving benefits of retrofitting the residential heating system from single-zone to multi-zone temperature control. The objective of this thesis is to design a physical model to simulate the thermal profile of a residential building with a conventional single-zone central heating system. A scale model of a 2-story house was designed and constructed at 1/20 of the length scale of an average lifesize house, with an external heater and five temperature sensors connected to Vernier LabPro for data acquisition. Comparison between scale model prediction and experimental result shows similarity in steady state values for temperature and characteristic heating/cooling time constants. This thesis is an important first step toward designing a model house for multi-zone heating studies.by Alice Su-Chin Yeh.S.B
Intelligent colour agent in world wide web interface design
Colour management is a vital aspect in interfaces design as it retains an overall balanced and coherent appearance of the interfaces.The appropriate combination use of colours creates diverse effect and enhances the outlook as well as
indirectly affects on the user acceptance and satisfaction of interfaces perceived.WWW interface designers often use up plenty of time and effort in mix-matching colours with the intention to obtain the most ultimate combination of the colours used.A poor colour management in WWW interfaces might not be able to convey its information to users efficiently and effectively. As a result, this paper aims to evaluate and resolve the appropriateness and inappropriateness use of colour in interface design, and proposed an intelligent colour agent to automate the process of considering and minimising the selection of the appropriateness use of colours.It has been safely concluded that the intelligent colour agent is capable of performing its tasks positively in analysing and consulting the suitable colours to be used and intensify the information transformation to and from the users.The visibility of interfaces has been examined to promote the contrast display between the users and machines
Influencing Policy. Raising Aspirations. Exploring the impact of the Street Child World Cup on the young people who participate, their communities and the organisations that support them
The Street Child World Cup (SCWC) aims to use the power of football and the arts to raise awareness of and tackle the widespread stigma faced by street-connected children globally. Through the tournament, an arts festival and the General Assembly, Street Child United (SCU) use each event to amplify the voices of these children in a bid to change how they are positioned and supported in society. As the fourth SCU event to be held since 2010, the 2018 SCWC provided an opportunity to reflect upon the challenges and opportunities that have arisen in relation to previous events as well as to focus on the event in Moscow as it unfolded. This independent research study, therefore, aimed to understand the impact of participating in a SCWC on the players, their communities and the organisations that support them. Data was generated through questionnaires distributed to Team Leaders before the event in Moscow, face-to-face interviews with Team Leaders, players and Youth Leaders at the event, and face-to-face or WhatsApp interviews with players and Team Leaders in the 18 months after the event. The findings indicate the importance of effective structures to create the foundation for meaningful participation and to ensure that being part of the SCWC is mostly a positive experience for the organisations who register to bring teams to the event and for the teams themselves. In particular, these structures relate to the development of programmes to prepare the teams for travelling to the event and supporting them when they return, as well as for advocacy strategies that lead to sustainable, long-term change. Key Findings Participating in a SCU event can be a confidence-building experience for the players. They are able to feel proud of being selected to represent their country, interact with and learn from children in similar situations to them but from other countries, and become motivated to complete their education and/or think about their future differently. A number of the organisations who register to participate in a SCU event integrate the opportunity into a wider programme focused on developing strong role models - either to provide peer support for other children or as a spokesperson within a larger advocacy programme. As such participating in a SCU event can provide positive benefits to the wider community by raising their aspirations also. Impact was greater, and generally more positive, when effective frameworks of support were in place. For example, the development of comprehensive programmes of preparation that: managed the expectations of players, parents and the wider community; developed integrated programmes of training to help the players to play together as a team; delivered child rights education to prepare them for the Congress; and focused on what was expected of the players (and the challenges they would face) when they returned home. Impact was also greater when these frameworks continued after the event, supporting the players with the emotional upheaval of returning to ‘normal’ life after being the centre of attention for 12 days. Good practice described by the Team Leaders include the provision of counselling, especially from a qualified counsellor, and/or at the very least a space in which the players are able to share their experiences and reconnect with other players who had been at the SCWC. As suggested by such frameworks, getting players to the event involves a great deal of work that can take the staff at the organisations fielding the teams away from their usual day-to-day work. In smaller organisations with less human resource capacity, other programmes of intervention can be affected as staff focus on getting everything in place to travel to the SCWC. The additional work includes, but is not limited to, fundraising to take the team to the event, selecting and training the team, applying for birth certificates, passports and other legal documents to take the children out of the country and the related tasks of finding and negotiating with potentially absent parents during the process. Most Team Leaders reported limited financial benefits to their organisations from their participation in the event but they all reported a degree of success in meeting advocacy goals. In general, larger organisations, or those who had participated for a number of SCU events and had spent years developing their approaches to both supporting the players and integrating the SCWC into their long-term advocacy strategy, were more able to engage with the media and negotiate the inclusion of their particular advocacy messages in the stories presented. In addition, the higher up the tournament leader board a team managed to reach, the greater the media coverage they attracted. This raises important questions about the support structures that could be put in place to both address the impact on workload and leverage greater impact from the event. The Congress, which provides a space in which the players share their stories and develop messages to disseminate on an international stage at the General Assembly, was described positively by most Team Leaders interviewed as the focus on the event. The players develop the confidence to reflect upon the challenges they faced – especially in relation to the problems faced by other teams – and to visualise solutions to these problems and a focus on the future. The messages the players develop for the General Assembly are rooted in the experiences they share and are therefore inextricably part of who they are. When these messages translate into limited tangible impact, which is to be expected given the nature of the event and the timescales over which transformative change takes place in practice, the players can be left disappointed after the hype of speaking in front of ‘the world’. Team Leaders who managed players expectations, by helping them to understand the degree to which delivering their messages leads to change as part of a long-term process that could take ears, reported greater levels of impact and confidence building for the players. These Team Leaders described follow-on programmes of advocacy and support that aimed to build on and develop the sustainability of these messages – involving the players in advocacy strategies and encouraging them to be role models for other street-connected children. Finally, SCU value long-term partnerships with the organisations who register to participate: developing an international network that can offer guidance and support to each other in their work. The networks developed between organisations was discussed positively in terms of providing supportive spaces where Team Leaders and other staff members could learn from each other. However, the ability of this network to deliver a stronger, collaborative, advocacy message was not discussed in positive terms and there were Team Leaders who wanted the network to be developed towards greater impact through a long-term focus on why children are on the street rather than just the event itself
Shape analysis on homogeneous spaces: a generalised SRVT framework
Shape analysis is ubiquitous in problems of pattern and object recognition
and has developed considerably in the last decade. The use of shapes is natural
in applications where one wants to compare curves independently of their
parametrisation. One computationally efficient approach to shape analysis is
based on the Square Root Velocity Transform (SRVT). In this paper we propose a
generalised SRVT framework for shapes on homogeneous manifolds. The method
opens up for a variety of possibilities based on different choices of Lie group
action and giving rise to different Riemannian metrics.Comment: 28 pages; 4 figures, 30 subfigures; notes for proceedings of the Abel
Symposium 2016: "Computation and Combinatorics in Dynamics, Stochastics and
Control". v3: amended the text to improve readability and clarify some
points; updated and added some references; added pseudocode for the dynamic
programming algorithm used. The main results remain unchange
Resolved Debris Discs Around A Stars in the Herschel DEBRIS Survey
The majority of debris discs discovered so far have only been detected
through infrared excess emission above stellar photospheres. While disc
properties can be inferred from unresolved photometry alone under various
assumptions for the physical properties of dust grains, there is a degeneracy
between disc radius and dust temperature that depends on the grain size
distribution and optical properties. By resolving the disc we can measure the
actual location of the dust. The launch of Herschel, with an angular resolution
superior to previous far-infrared telescopes, allows us to spatially resolve
more discs and locate the dust directly. Here we present the nine resolved
discs around A stars between 20 and 40 pc observed by the DEBRIS survey. We use
these data to investigate the disc radii by fitting narrow ring models to
images at 70, 100 and 160 {\mu}m and by fitting blackbodies to full spectral
energy distributions. We do this with the aim of finding an improved way of
estimating disc radii for unresolved systems. The ratio between the resolved
and blackbody radii varies between 1 and 2.5. This ratio is inversely
correlated with luminosity and any remaining discrepancies are most likely
explained by differences to the minimum size of grain in the size distribution
or differences in composition. We find that three of the systems are well fit
by a narrow ring, two systems are borderline cases and the other four likely
require wider or multiple rings to fully explain the observations, reflecting
the diversity of planetary systems.Comment: 19 pages, 13 figures, 6 tables. Accepted for publication in MNRA
Frequency swept pulses for the enhanced resolution of ENDOR spectra detecting on higher spin transitions of Gd(III)
The debris disk around gamma Doradus resolved with Herschel
We present observations of the debris disk around gamma Doradus, an F1V star,
from the Herschel Key Programme DEBRIS (Disc Emission via Bias-free
Reconnaissance in the Infrared/Submillimetre). The disk is well-resolved at 70,
100 and 160 micron, resolved along its major axis at 250 micron, detected but
not resolved at 350 micron, and confused with a background source at 500
micron. It is one of our best resolved targets and we find it to have a
radially broad dust distribution. The modelling of the resolved images cannot
distinguish between two configurations: an arrangement of a warm inner ring at
several AU (best-fit 4 AU) and a cool outer belt extending from ~55 to 400 AU
or an arrangement of two cool, narrow rings at ~70 AU and ~190 AU. This
suggests that any configuration between these two is also possible. Both models
have a total fractional luminosity of ~10^{-5} and are consistent with the disk
being aligned with the stellar equator. The inner edge of either possible
configuration suggests that the most likely region to find planets in this
system would be within ~55 AU of the star. A transient event is not needed to
explain the warm dust's fractional luminosity.Comment: 12 pages, 6 figures, accepted for publication in Ap
INTELLIGENT COLOUR AGENT IN WORLD WIDE WEB INTERFACE DESIGN
ABSTRACT Colour management is a vital aspect in interfaces design as it retains an overall balanced and coherent appearance of the interfaces. The appropriate combination use of colours creates diverse effect and enhances the outlook as well as indirectly affects on the user acceptance and satisfaction of interfaces perceived. WWW interface designers often use up plenty of time and effort in mix-matching colours with the intention to obtain the most ultimate combination of the colours used. A poor colour management in WWW interfaces might not be able to convey its information to users efficiently and effectively. As a result, this paper aims to evaluate and resolve the appropriateness and inappropriateness use of colour in interface design, and proposed an intelligent colour agent to automate the process of considering and minimising the selection of the appropriateness use of colours. It has been safely concluded that the intelligent colour agent is capable of performing its tasks positively in analysing and consulting the suitable colours to be used and intensify the information transformation to and from the users. The visibility of interfaces has been examined to promote the contrast display between the users and machines. KEYWORDS Intelligent colour agent, interface design, WWW
Improved Lumped Models for Transient Combined Convective and Radiative Cooling of Multilayer Spherical Media
In this work, we studied the transient combined convection and radiation of multilayer spherical media with volumetric heat generation, extending the previous work on the particular case of a spherical body subjected to radiative cooling. The proposed lumped models were obtained through two-point Hermite approximations for the average temperature and heat flux in each layer. For the average temperature, the plain trapezoidal rule (H0,0 approximation) was employed in all layers, except for the innermost layer, where the second-order two-side corrected trapezoidal rule (H2,1 approximation) was utilized. For the heat flux, the plain trapezoidal rule (H0,0 approximation) was employed for all the layers. The transient heat conduction in a TRISO-coated fuel particle being composed of five layers (namely, fuel kernel, buffer of porous carbon, inner pyrocarbon, silicon carbide, and outer pyrocarbon) was analyzed using the proposed lumped models, the results of which were verified by comparison with the finite difference solution of the original distributed parameter model. Parametric studies were conducted to examine the effects of the dimensionless heat generation rate, the radiation-conduction parameter, and the Biot number on the temporal variations of the average temperatures
Effects of resveratrol supplementation on methotrexate chemotherapy‐induced bone loss
Intensive cancer chemotherapy is known to cause bone defects, which currently lack treatments. This study investigated the effects of polyphenol resveratrol (RES) in preventing bone defects in rats caused by methotrexate (MTX), a commonly used antimetabolite in childhood oncology. Young rats received five daily MTX injections at 0.75 mg/kg/day. RES was orally gavaged daily for seven days prior to, and during, five‐day MTX administration. MTX reduced growth plate thickness, primary spongiosa height, trabecular bone volume, increased marrow adipocyte density, and increased mRNA expression of the osteogenic, adipogenic, and osteoclastogenic factors in the tibial bone. RES at 10 mg/kg was found not to affect bone health in normal rats, but to aggravate the bone damage in MTX‐treated rats. However, RES supplementation at 1 mg/kg preserved the growth plate, primary spongiosa, bone volume, and lowered the adipocyte density. It maintained expression of genes involved in osteogenesis and decreased expression of adipogenic and osteoclastogenic factors. RES suppressed osteoclast formation ex vivo of bone marrow cells from the treated rats. These data suggest that MTX can enhance osteoclast and adipocyte formation and cause bone loss, and that RES supplementation at 1 mg/kg may potentially prevent these bone defects
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