2,177 research outputs found
An approach for assessing software prototypes
A procedure for evaluating a software prototype is presented. The need to assess the prototype itself arises from the use of prototyping to demonstrate the feasibility of a design or development stategy. The assessment procedure can also be of use in deciding whether to evolve a prototype into a complete system. The procedure consists of identifying evaluations criteria, defining alterative design approaches, and ranking the alternatives according to the criteria
Electrochemical Energy Storage Subsystems Study, Volume 2
The effects on life cycle costs (LCC) of major design and performance technology parameters for multi kW LEO and GEO energy storage subsystems using NiCd and NiH2 batteries and fuel cell/electrolysis cell devices were examined. Design, performance and LCC dynamic models are developed based on mission and system/subsystem requirements and existing or derived physical and cost data relationships. The models are exercised to define baseline designs and costs. Then the major design and performance parameters are each varied to determine their influence on LCC around the baseline values
Electrochemical energy storage subsystems study, volume 1
The effects on life cycle costs (LCC) of major design and performance technology parameters for multi kW LEO and GEO energy storage subsystems using NiCd and NiH2 batteries and fuel cell/electrolysis cell devices were examined. Design, performance and LCC dynamic models are developed based on mission and system/subsystem requirements and existing or derived physical and cost data relationships. The models define baseline designs and costs. The major design and performance parameters are each varied to determine their influence on LCC around the baseline values
Complexity-based learning and teaching: a case study in higher education
This paper presents a learning and teaching strategy based on complexity science and explores its impacts on a higher education game design course. The strategy aimed at generating conditions fostering individual and collective learning in educational complex adaptive systems, and led the design of the course through an iterative and adaptive process informed by evidence emerging from course dynamics. The data collected indicate that collaboration was initially challenging for students, but collective learning emerged as the course developed, positively affecting individual and team performance. Even though challenged, students felt highly motivated and enjoyed working on course activities. Their perception of progress and expertise were always high, and the academic performance was on average very good. The strategy fostered collaboration and allowed students and tutors to deal with complex situations requiring adaptation
Policy adequacy, inclusion, and commitment: Impact of Household Expenditure in Education in China
251 Economics of educational attainment and quality ; Theme: Education and Labour ForceGlobally, labor migration is an essential component of the 21st century. Much of the existing research on the consequences of labor migration on the family has focused primarily on the economic consequences while the consequences for social protection have received less attention. Within in China, the Hukou household registration system, based on place of residence and administered by local municipalities, continues to be the primary mechanism through which people are eligible for government-subsidized social protection programs including public education. Decades of widespread ‘temporary’ migration of working-age population into urban centers are disrupting this place-based eligibility system of resource allocation. This current study examines the intersectionality of education policy and migration and the impacts on household educational expenditure.
This paper explores the relationship between the policy environment, education and social inclusion using a cohort of children (aged 6 to 16 in 2010) from the China Family Panel Study (CFPS) combined with secondary data collected from the China Statistical Yearbooks. The multilevel modeling suggested that low commitment (higher teacher-student ration) is negatively associated with household expenditure in education. The community migrant population explain variability in educational expenditure across migrant and local resident households. The implication for educational inclusion and equity are discussed.postprin
Time evolution, cyclic solutions and geometric phases for general spin in an arbitrarily varying magnetic field
A neutral particle with general spin and magnetic moment moving in an
arbitrarily varying magnetic field is studied. The time evolution operator for
the Schr\"odinger equation can be obtained if one can find a unit vector that
satisfies the equation obeyed by the mean of the spin operator. There exist at
least cyclic solutions in any time interval. Some particular time
interval may exist in which all solutions are cyclic. The nonadiabatic
geometric phase for cyclic solutions generally contains extra terms in addition
to the familiar one that is proportional to the solid angle subtended by the
closed trace of the spin vector.Comment: revtex4, 8 pages, no figur
Understanding light quanta: First quantization of the free electromagnetic field
The quantization of the electromagnetic field in vacuum is presented without
reference to lagrangean quantum field theory. The equal time commutators of the
fields are calculated from basic principles. A physical discussion of the
commutators suggest that the electromagnetic fields are macroscopic emergent
properties of more fundamental physical system: the photons
Understanding older adults’ perceptions of and attitudes towards exergames
Purpose Maintaining physical activity is a key component of successful aging and has benefits for both physical and cognitive
functioning in the older adult population. One promising method for engaging in physical activity is through exergames, which are video games designed to promote exercise. Exergames have the potential to be used by a wide range of people, including older adults, in a variety of settings, such as at home, in community living environments, or senior centers. However, exergames have not been designed for older adults (e.g., with respect to their attitudes, needs). Thus, older adults may not adopt these systems if they perceive them as not useful or relevant to them. Method Twenty older adults (aged 60-79) interacted with two exergames, and were then interviewed about their perceptions of the system’s ease of use and usefulness, as well as their general attitudes towards the system. Results Participants identified the potential for exergames’ usefulness for various goals, such as to increase their physical activity. However, they also reported negative attitudes concerning the system, including perceiving barriers to system use. Overall, participants said they would use the system in the future and recommend it to other people at their age for improving health, despite these use challenges. Conclusion The older adults were open to adopting exergames,
which could provide opportunities to increase physical activity. Given the participants’ overall positive perceptions of the usefulness of exergames, designers must address the perceived challenges of using these systems. Understanding barriers and facilitators for older adults’ use of exergames can guide design, training, and adoption of these systems
The Detonation Mechanism of the Pulsationally-Assisted Gravitationally-Confined Detonation Model of Type Ia Supernovae
We describe the detonation mechanism comprising the "Pulsationally Assisted"
Gravitationally Confined Detonation (GCD) model of Type Ia supernovae SNe Ia.
This model is analogous to the previous GCD model reported in Jordan et
al.(2008); however, the chosen initial conditions produce a substantively
different detonation mechanism, resulting from a larger energy release during
the deflagration phase. The resulting final kinetic energy and nickel-56 yields
conform better to observational values than is the case for the "classical" GCD
models. In the present class of models, the ignition of a deflagration phase
leads to a rising, burning plume of ash. The ash breaks out of the surface of
the white dwarf, flows laterally around the star, and converges on the
collision region at the antipodal point from where it broke out. The amount of
energy released during the deflagration phase is enough to cause the star to
rapidly expand, so that when the ash reaches the antipodal point, the surface
density is too low to initiate a detonation. Instead, as the ash flows into the
collision region (while mixing with surface fuel), the star reaches its
maximally expanded state and then contracts. The stellar contraction acts to
increase the density of the star, including the density in the collision
region. This both raises the temperature and density of the fuel-ash mixture in
the collision region and ultimately leads to thermodynamic conditions that are
necessary for the Zel'dovich gradient mechanism to produce a detonation. We
demonstrate feasibility of this scenario with three 3-dimensional (3D), full
star simulations of this model using the FLASH code. We characterized the
simulations by the energy released during the deflagration phase, which ranged
from 38% to 78% of the white dwarf's binding energy. We show that the necessary
conditions for detonation are achieved in all three of the models.Comment: 22 pages, 8 figures; Ap
- …