157 research outputs found
Justifying patents: a critique of the deontological approach
No full textThis thesis assesses philosophical arguments in favour of patent systems. These come in both consequentialist and deontological forms, the latter of which are the focus of this analysis. One kind of deontological argument is based on the concept of desert. I argue that on any plausible conception of desert, the patent system fails to distribute rewards as well as viable alternative systems could. The other kind of deontological argument claims that inventors are entitled to patent rights over their inventions as an extension of their natural rights, drawing on a Lockean account of the conditions of legitimate appropriation of unowned goods. After a discussion of the metaphysics of invention, and of the nature of the commons, I argue that Locke's conditions are not in fact always trivially satisfied in the case of patents. Furthermore, entitlement-based arguments conclude that because new inventions are unowned, claiming property rights in them involves only the same moral considerations that would apply in the state of nature. I argue that because we are not in the state of nature, pre-existing property rights also need to be taken into account, which conflict with patents. The broad conclusion of this thesis is that none of the plausible deontological arguments for patent systems are sound. The implication is that any justification of must therefore be made in consequentialist terms; this ultimately rests on strong empirical evidence rather than normative arguments alone
Screening older people for impaired vision
No full textA systematic review of trials about screening
older
people
for
visual
impairment found no evidence that screening
improved
vision.
We
undertook
a new trial nested within a larger cluster randomised
trial
of
multidimensional
screening for people aged 75 years and over.
106
general
practices
were
randomised to: targeted screening in which only a small
proportion
of
participants with a range of health problems
were offered
visual
acuity
screening, and universal screening
in
which all
participants
were offered
visual acuity screening. People identified with
impaired
vision
were
referred
to the eye services. Around 220 participants were randomly
sampled
from
ten practices in each group and visual outcomes measured
at
three to five
years.
The response rate to the baseline assessments was
76.1
Over
one
third
of
eligible participants died before having an outcome assessment.
Of those
alive, 67.8% in the targeted screening group
and
57.9% in the
universal
group completed an outcome assessment.
At
outcome
37.0%
(307/829) in
the universal group had visual acuity of
less than
6/18 in
either eye compared
with 34.7% (339/978) in the targeted group
(odds
ratio
1.11,95%
confidence
interval 0.76 to 1.62, P=0.58). The 25 item
National Eye Institute
Visual
Function Questionnaire composite score
was
86.03 in the
universal group
and 85.62 in the targeted group (difference 0.41,95%
confidence
interval
-
1.68 to 2.50, P=0.69). Although visual
impairment
was
common,
few
people
benefited from subsequent intervention. Possible
explanations
for the lack
of
effect include: chance; under-detection of uncorrected
refractive
error
and
that only around half the recommendations
for
referral
to
an
ophthalmologist
resulted in referral
A synchronous communication system for a software-based Byzantine fault tolerant computer
No full textThesis (M. Eng.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2006.This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.Includes bibliographical references (p. 155-156).This thesis describes the redesign of a Byzantine-resilient, quad-redundant computer to remove proprietary hardware components. The basic architecture consists of four Commercial Off-The-Shelf (COTS) processors in a completely-connected network of point-to-point ethernet connections. In particular, the focus of this thesis is an algorithm that combines clock synchronization and communications between fault containment regions by inferring relative clock skew from the arrival time of expected messages. Both a failsafe and a fault-tolerant algorithm are discussed, though the fault-tolerant algorithm is not fully analyzed. The performance of a prototype and the failsafe synchronization algorithm are discussed.by Reuben Marbell Sterling.M.Eng
The influence of advertisement familiarity and originality on visual attention and brand memory.
No full textBased on Mandler's theory of schema organization and previous visual attention research, we formulate and test hypotheses about the impact of ad familiarity and ad originality on attention and memory for print advertisements. To that end, one hundred and nineteen consumers browsed through two consumer magazines containing 68 print advertisements. Attention to the ads and their brand, picture and text components was assessed through infrared eye tracking. Trained judges rated the ads independently for familiarity and originality. In support of the hypotheses we find a sharp attention decline with ad familiarity, which is largely due to a reduction in attention to text. Originality of ad execution serves as a buffer against the negative influence of ad familiarity on attention, but only for the brand and picture components. The reduction of attention to the text is even larger for original than for unoriginal ads. Moreover, over and above their indirect influence through visual attention patterns, ad familiarity, ad originality and their interaction had a direct influence on brand memory.Advertising;
Determination of salient design elements through eye movements, aesthetics, and usability
No full textThe goal of study 1 was to use a remote eye tracker to understand how eye movements change with 7 geometrically varied remote controls to determine design element saliency. 20 participants were used to measure the following eye metrics: number of fixations prior to first fixation of any AOI, time to first fixation of an AOI, number of fixations on an AOI, dwell time of the first fixation on an AOI, total dwell time of an AOI, and the percentage of time spent on an AOI. The results of the study showed that all participants spent between 75–85% of their time fixated on the button layout which was not defined as an AOI. No statistical differences were found in the values measured for all eye tracking metrics across similarly defined AOIs. In study 2, the objective was to determine attitudes towards appearance and usability of the 7 remote control designs using the participants from study 1. Participants were asked to rate their attitudes and preferences, using a Likert-based questionnaire, about the qualities of appearance and usability for the attributes of proportion, shape, and configuration. They were asked open-ended questions about their likes and dislikes regarding the qualities of appearance and usability. Lastly, participants were given a pairwise comparison survey where they chose their preferred remote design, based on appearance, for 10 paired sets of contrasting remote designs. The hourglass subjacent and hourglass round designs were rated highest for appearance and usability from the Likert questionnaire. The hourglass round design was ranked highest for the pairwise comparison survey. For study 3, the goal was to determine attitudes towards appearance and usability of the 7 remote designs with online participants. 300 participants were asked to rate their attitudes and preferences using the same Likert-based questionnaire from study 2. They were asked the same open-ended questions and administered the same pairwise comparison survey as in study 2. The results of the Likert questionnaire showed that the hourglass subjacent and hourglass round designs were rated highest for appearance and usability. From the pairwise comparison survey, the hourglass round design was ranked the highest
Wealth, household heterogeneity and livelihood diversification of Fulani pastoralists in the Kachia Grazing Reserve, northern Nigeria, during a period of social transition
No full textBACKGROUND: A mixed methods study was undertaken in the Kachia Grazing Reserve of northern Nigeria. Surveys in March, June and October 2011 included focus group discussions, key informant and in-depth household interviews, concerning livelihood practices, animal health, ownership, and productivity. In May 2011, 249 Fulani families fleeing post-election violence entered the reserve with their livestock, increasing the number of households by one third.RESULTS: Despite being settled within a grazing reserve, over half of households sent all their cattle away on seasonal transhumance and another third sent some away. Cattle accounted for 96% of total tropical livestock units (TLU), of which 26% were cattle kept permanently outside the reserve. While all households cited livestock as their main source of income, 90% grew crops and 55% derived income from off-farm activities. A multiple correspondence analysis showed that for each extra member of a household its TLU value increased by 2.0 [95% CI, 1.4-2.7], while for each additional marriage its TLU increased by 15.7 [95% CI, 7.1-24.3]. A strong association was also observed between small herds, small households with only one wife, alongside marked geographical wealth differences within the reserve. New immigrant families had larger household sizes (33) and livestock holdings (122 TLU) than old settlers (22 people and 67 TLU). Prior to the mass immigration, the distribution of TLU per person was unimodal: 41% of households were classified as 'poor' and 27% as 'medium', whereas post-immigration it was bi-modal, with 26% classified as 'very poor' and 28% as 'medium'.CONCLUSIONS: While cattle remain the principal source of Fulani income and wealth, the inhabitants of Kachia Grazing Reserve have diversified their livelihood strategies to respond to changing circumstances and stress, especially the limited availability of grazing within the reserve and political insecurity outside, resulting in continued transhumance, the maintenance of smaller livestock holdings and pushing households into poverty.</p
Performativity and antagonism as keystones for a political geography of change
No full textThis chapter develops a theoretical framework for a political geography of change that takes into account the power relations and resulting hegemonies and acts of marginalization, which constitute the very spaces of politics. It contributes the ongoing discussions in political geography about the relation between politics/the political, space, and social change by showing how are spaces of politics brought into being through regulatory, citational practices and performances. The chapter explores how are hegemonic spaces of politics reproduced, constructed and contested by counter-hegemonic political practices and what kinds of spaces of politics result from politics of antagonism and what might an agonistic space of politics look like. The author argues that for realizing the potential of Butlers work for political geography, it is crucial to draw her writings in which she engages more directly with questions of social transformation, norms, politics, and democracy. The concept of performativity focuses attention on the everyday political practices that constitute the political spaces of antagonism
Dynamic measurement of intraocular pressure using a mechanical model of the human eye.
No full textHeightened intraocular pressure (IOP) is not always indicative of glaucoma, but is an important risk factor for the progression of certain types of eye damage not obviously felt by the sufferer. A number of measurement systems have been devised in the past to measure the IOP by applying force or pressure to the cornea, but past studies have shown that the cornea thickness and its curvature have a significant effect on measurements which may ultimately lead to clinical misdiagnosis. A cyclic strain controlled dynamic probing measurement system has been developed using an indenter of diameter 3.06 mm operating at actuation frequencies of between 0.1 Hz and 4 Hz and displacements up to 1 mm. The cyclic strain is actuated by a linear stage with a load cell and indenter coupled in series. The load cell records the resultant cyclic force where the dynamic modulus is expressed as amplitude ratio and phase lag. The mechanical eye model consists of a silicone membrane that can be varied in thickness and it is distended hydraulically to simulate a range of IOP. A pressure sensor measures the dynamic IOP within the system which will be compared against the dynamic modulus. The relationship between the mechanical properties and the physical properties of the membrane will be established in order to develop a probe which can be used clinically taking into account the effects of corneal stiffness and hydraulic behaviour of the eye. The preliminary study reported here a significant increase in amplitude ratio and mean ratio with increasing the frequency similar to the behaviour found in biological materials and gelatin.</p
Are Ghana's roads paying their way? Assessing road use cost and user charges in Ghana
No full textThe author studied how much road damage contributes to road use costs in Ghana and how the marginal social costs should be recovered. This required understanding the road deterioration process better and analyzing the implications for vehicle operating costs and road user charges. The most important thing learned is that studies of road-user costs are feasible in reputedly data-poor countries. The author found that to bridge the gap between road-user costs and charges, the annual fee for heavy trucks should be raised tenfold. Fuel taxes alone are not adequate to distinguish fully the large difference in road damage costs incurred by heavy trucks and private cars. The taxing instrument most deficient in Ghana is the annual licensing fee. Not only should licensing fees for heavy trucks be ten times higher than they are now, but exemptions from the licensing fee should be canceled and registration rules strictly enforced. Even then, charges on heavy vehicles will not cover costs unless current legal limits of axle loading are obeyed. A more efficient means of reducing the damaging effects of heavy vehicles lies in structuring the annual fees to reflect how much more damaging two-axle heavy vehicles are than multiaxle vehicles. The issue of redistribution of costs and fees is of secondary importance in Ghana because of low fuel consumption, low level of fuel taxes, and the fact that expenditures on fuels are proportionately the same for the poor and the nonpoor.Roads&Highways,Airports and Air Services,Transport and Environment,Urban Transport,Public Sector Economics&Finance
Initial segments and end-extensions of models of arithmetic
No full textThis thesis is organized into two independent parts. In the first part, we extend the recent work on generic cuts by Kaye and the author. The focus here is the properties of the pairs (M, I) where I is a generic cut of a model M. Amongst other results, we characterize the theory of such pairs, and prove that they are existentially closed in a natural category. In the second part, we construct end-extensions of models of arithmetic that are at least as strong as ATR. Two new constructions are presented. The first one uses a variant of Fodor’s Lemma in ATR to build an internally rather classless model. The second one uses some weak versions of the Galvin–Prikry Theorem in adjoining an ideal set to a model of second-order arithmetic
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