5,931 research outputs found
Applying the proto-theory of design to explain and modify the parameter analysis method of conceptual design
This article reports on the outcomes of applying the notions provided by the reconstructed proto-theory of design, based on Aristotleâs remarks, to the parameter analysis (PA) method of conceptual design. Two research questions are addressed: (1) What further clarification and explanation to the approach of PA is provided by the proto-theory? (2) Which conclusions can be drawn from the study of an empirically derived
design approach through the proto-theory regarding usefulness, validity and range of that theory? An overview of PA and an application example illustrate its present model and unique characteristics. Then, seven features of the proto-theory are explained and demonstrated through geometrical problem solving and analogies are drawn between these features and the corresponding ideas in modern design thinking.
Historical and current uses of the terms analysis and synthesis in design are also outlined and contrasted, showing that caution should be exercised when applying them. Consequences regarding the design moves, process and strategy of PA allow proposing modifications to its model, while demonstrating how the ancient method of analysis can contribute to better understanding of contemporary design-theoretic issues
Robust DEA efficiency scores: A probabilistic/combinatorial approach
In this paper we propose robust efficiency scores for the scenario in which
the specification of the inputs/outputs to be included in the DEA model is
modelled with a probability distribution. This proba- bilistic approach allows
us to obtain three different robust efficiency scores: the Conditional Expected
Score, the Unconditional Expected Score and the Expected score under the
assumption of Maximum Entropy principle. The calculation of the three
efficiency scores involves the resolution of an exponential number of linear
problems. The algorithm presented in this paper allows to solve over 200
millions of linear problems in an affordable time when considering up 20
inputs/outputs and 200 DMUs. The approach proposed is illustrated with an
application to the assessment of professional tennis players
A study on subarcsecond scales of the ammonia and continuum emission toward the G16.59-0.05 high-mass star-forming region
We wish to investigate the structure, velocity field, and stellar content of
the G16.59-0.05 high-mass star-forming region, where previous studies have
established the presence of two almost perpendicular (NE-SW and SE-NW), massive
outflows, and a rotating disk traced by methanol maser emission. We performed
Very Large Array observations of the radio continuum and ammonia line emission,
complemented by COMICS/Subaru and Hi-GAL/Herschel images in the mid- and
far-infrared (IR). Our centimeter continuum maps reveal a collimated radio jet
that is oriented E-W and centered on the methanol maser disk, placed at the SE
border of a compact molecular core. The spectral index of the jet is negative,
indicating non-thermal emission over most of the jet, except the peak close to
the maser disk, where thermal free-free emission is observed. We find that the
ammonia emission presents a bipolar structure consistent (on a smaller scale)
in direction and velocity with that of the NE-SW bipolar outflow detected in
previous CO observations. After analyzing our previous N2H+(1-0) observations
again, we conclude that two scenarios are possible. In one case both the radio
jet and the ammonia emission would trace the root of the large-scale CO bipolar
outflow. The different orientation of the jet and the ammonia flow could be
explained by precession and/or a non-isotropic density distribution around the
star. In the other case, the N2H+(1-0) and ammonia bipolarity is interpreted as
two overlapping clumps moving with different velocities along the line of
sight. The ammonia gas also seems to undergo rotation consistent with the maser
disk. Our IR images complemented by archival data allow us to derive a
bolometric luminosity of about 10^4 L_sun and to conclude that most of the
luminosity is due to the young stellar object associated with the maser disk.Comment: 11 pages, 12 figures, published in Astronomy and Astrophysic
High resolution observations of Cen A: Yellow and red supergiants in a region of jet-induced star formation?
We present the analysis of near infrared (NIR), adaptive optics (AO) Subaru
and archived HST imaging data of a region near the northern middle lobe (NML)
of the Centaurus A (Cen A) jet, at a distance of kpc north-east (NE)
from the center of NGC5128. Low-pass filtering of the NIR images reveals strong
-- above the background mean -- signal at the expected position of
the brightest star in the equivalent HST field. Statistical analysis of the NIR
background noise suggests that the probability to observe signal at
the same position, in three independent measurements due to stochastic
background fluctuations alone is negligible () and, therefore,
that this signal should reflect the detection of the NIR counterparts of the
brightest HST star. An extensive photometric analysis of this star yields
, visual-NIR, and NIR colors expected from a yellow supergiant (YSG) with
an estimated age Myr. Furthermore, the second and third
brighter HST stars are, likely, also supergiants in Cen A, with estimated ages
Myr and Myr, respectively. The ages of
these three supergiants are in good agreement with the ages of the young
massive stars that were previously found in the vicinity and are thought to
have formed during the later phases of the jet-HI cloud interaction that
appears to drive the star formation (SF) in the region for the past
Myr.Comment: 11 pages, 6 figures, 2 tables, accepted for publication in Ap
The Measurement of Student Motivation: Does one Scale do it All?
This article focuses on the use of the Academic Motivation Scale in measuring motivation levels in undergraduate business students. The article poses the question whether this scale, which works in tandem with Self Determination Theory is an adequate motivation scale in the measure of student motivation. Other measurement scales are explored which do not have a corresponding motivation theory in order to highlight the complexity of this area of research. 232 undergraduate business students are administered the Academic Motivation Scale and results indicate that these students are severely lacking in subject motivation to such an extent that other options of measurement must be considered before research can validate the scale as being an appropriate measurement of business student motivation
Assessing the impact and antecedents of university scientific research on firms’ innovation commercialisation
An Examination of Tax Expenditures for Educator Expenses under Internal Revenue Code §62(a)(2)(D): A Policy Analysis
In a society where emphasis is placed on student achievement and teachers are pressured to raise academic standards, data indicate that teachers spend a significant amount of their own money to ensure that students have the materials and supplies needed to learn and ultimately succeed while in the classroom. SASS (Schools and Staffing Survey/National Center for Education Statistics/nces.ed.gov) reported that in 2007-2008, approximately 92.4% teachers spent their own money for classroom supplies; the average amount used to purchase materials amounted to 1.6 billion of their own money to purchase student supplies. In 2002, in response to such concerns, Congress enacted Internal Revenue Code (IRC) §62(a)(2)(D), otherwise known as the Educator Expenses Deduction, which allows teachers who instruct in K-12 to deduct up to 500 if married filing jointly and both spouses are educators) of any unreimbursed education expenses. Many of these expenses include books, supplies, computer equipment, and supplementary materials used in the classroom that would otherwise be deductible under §162 (Ordinary and Necessary Business Expenses), but subject to a 2 % Adjusted Gross Income Limitation. The Educator Expenses Deduction has been expended several times since 2004, and is set to expire after December 31, 2013. The purpose of this paper is to examine the extent taxpayers have benefited from this provision, summarizing the legislative history, and make the argument that §62(a)(2)(D) be made a permanent provision; in addition, the authors have evidence to support the claim that the provision should be expanded to allow parents of qualified dependents enrolled in K-12 schools to deduct similar ancillary non-instructional costs, which are currently non-deductible
Dimethoxymethane oxidation in a flow reactor
The simultaneous reduction of NOx and soot emissions from diesel engines is a major research subject and a challenge in todayâs world. One prospective solution involves diesel fuel reformulation by addition of oxygenated compounds, such as dimethoxymethane (DMM). In this context, different DMM oxidation experiments have been carried out in an atmospheric pressure gas-phase installation, in the 573â1373 K temperature range, from pyrolysis to fuel-lean conditions. The results obtained have been interpreted by means of a detailed gas-phase chemical kinetic mechanism. Results indicate that the initial oxygen concentration slightly influences the consumption of DMM. However, certain effects can be observed in the profiles of the main products (CH4, CH3OH, CH3OCHO, CO, CO2, C2H2, C2H4, and C2H6). Acetylene, an important soot precursor, is only formed under pyrolysis and reducing conditions. In general, a good agreement between experimental and modeling data was observed
- âŠ