5,825 research outputs found
Rethinking Invention: Cognition and the Economics of Technological Creativity
Economists have typically not devoted much attention to the act of invention. This paper attempts to redress this situation by exploring a form of cognition, analogical transfer, which is thought by some researchers to lie at the heart of successful creativity. An analogical transfer is said to have occurred when information and experiences from one known situation is retrieved and utilized in the search for the solution to an entirely different situation. This paper shows how such analogical thought can give rise to a theoretical framework, in which disparate factors pertaining to technological creativity can be pieced together to yield an explanation of the level of inventive output experienced.invention, technological change, technological creativity, problem solving, learning.
Application of optimization techniques to vehicle design: A review
The work that has been done in the last decade or so in the application of optimization techniques to vehicle design is discussed. Much of the work reviewed deals with the design of body or suspension (chassis) components for reduced weight. Also reviewed are studies dealing with system optimization problems for improved functional performance, such as ride or handling. In reviewing the work on the use of optimization techniques, one notes the transition from the rare mention of the methods in the 70's to an increased effort in the early 80's. Efficient and convenient optimization and analysis tools still need to be developed so that they can be regularly applied in the early design stage of the vehicle development cycle to be most effective. Based on the reported applications, an attempt is made to assess the potential for automotive application of optimization techniques. The major issue involved remains the creation of quantifiable means of analysis to be used in vehicle design. The conventional process of vehicle design still contains much experience-based input because it has not yet proven possible to quantify all important constraints. This restraint on the part of the analysis will continue to be a major limiting factor in application of optimization to vehicle design
COMPLACENT OR COMPETITIVE? BRITISH EXPORTERS AND THE DRIFT TO EMPIRE
The belief that Britain’s empire markets were soft is well entrenched in the literature. It is, however, a belief that has been largely untested. Indeed, the literature does not even offer an explicit definition of softness. This paper attempts to fill this gap by discussing the meaning of the term and, then, posing the question whether between 1870 and 1914 Britain’s fastest growing markets – Australasia and Canada – can in fact be reasonably labelled soft, as has often been assumed. The paper concludes that the demand for British imports in these markets were driven more by income and price considerations than by colonial sentiment or preference.Empire markets, soft markets, British exports, imperial sentiments
Enhanced tracking and recognition of moving objects by reasoning about spatio-temporal continuity.
A framework for the logical and statistical analysis and annotation of dynamic scenes containing occlusion and other uncertainties is presented. This framework consists
of three elements; an object tracker module, an object recognition/classification module and a logical consistency, ambiguity and error reasoning engine. The principle behind the object tracker and object recognition modules is to reduce error by increasing ambiguity (by merging objects in close proximity and presenting multiple
hypotheses). The reasoning engine deals with error, ambiguity and occlusion in a unified framework to produce a hypothesis that satisfies fundamental constraints
on the spatio-temporal continuity of objects. Our algorithm finds a globally consistent model of an extended video sequence that is maximally supported by a voting function based on the output of a statistical classifier. The system results
in an annotation that is significantly more accurate than what would be obtained
by frame-by-frame evaluation of the classifier output. The framework has been implemented
and applied successfully to the analysis of team sports with a single
camera.
Key words: Visua
Using spatio-temporal continuity constraints to enhance visual tracking of moving objects
We present a framework for annotating dynamic scenes involving occlusion and other uncertainties. Our system comprises an object tracker, an object classifier and an algorithm for reasoning about spatio-temporal continuity. The principle behind the object tracking and classifier modules is to reduce error by increasing ambiguity (by merging objects in close proximity and presenting multiple hypotheses). The reasoning engine resolves error, ambiguity and occlusion to produce a most likely hypothesis, which is consistent with global spatio-temporal continuity constraints. The system results in improved annotation over frame-by-frame methods. It has been implemented and applied to the analysis of a team sports video
Summary report: A preliminary investigation into the use of fuzzy logic for the control of redundant manipulators
The Rice University Department of Mechanical Engineering and Materials Sciences' Robotics Group designed and built an eight degree of freedom redundant manipulator. Fuzzy logic was proposed as a control scheme for tasks not directly controlled by a human operator. In preliminary work, fuzzy logic control was implemented for a camera tracking system and a six degree of freedom manipulator. Both preliminary systems use real time vision data as input to fuzzy controllers. Related projects include integration of tactile sensing and fuzzy control of a redundant snake-like arm that is under construction
A Study of the Structure of the Transition Metal Hydryls Final Report
Crystal and molecular structures of transition rhodium and lithium hydril
Cohort, Year and Age Effects in Canadian Wage Data
We use Canadian Surveys of Consumer Finances 1971-1993 to study the wages of full-time, full-year male and female workers. Median real wages of 24-year-old males without a university degree fell by 25% between 1978 and 1993. For 24-year-old females the decline was more modest and reversed in 1987, but real wages in 1993 were still significantly lower than they were in 1978. We investigate whether these changes are permanent "cohort" effects or more temporary "year" effects. Graphs of median wages against year and age indicate some periods where year effects are more prominent than cohort effects and other periods where the reverse is true. We then compare the results from two models, one assigning the trends to year effects, the other assigning them to cohort effects, and use these models to produce real wage projections.SCF; wages; cohort
Structural controls on the location, geometry and longevity of an intraplate volcanic system: the Tuatara Volcanic Field, Great South Basin, New Zealand
Intraplate volcanism is widely distributed across the continents, but the controls on the 3D geometry and longevity of individual volcanic systems remain poorly understood. Geophysical data provide insights into magma plumbing systems, but, as a result of the relatively low resolution of these techniques, it is difficult to evaluate how magma transits highly heterogeneous continental interiors. We use borehole-constrained 2D seismic reflection data to characterize the 3D geometry of the Tuatara Volcanic Field located offshore New Zealand's South Island and investigate its relationship with the pre-existing structure. This c. 270 km2 field is dominated by a dome-shaped lava edifice, surrounded and overlain by c. 69 volcanoes and >70 sills emplaced over 40 myr from the Late Cretaceous to Early Eocene (c. 85–45 Ma). The Tuatara Volcanic Field is located above a basement terrane boundary represented by the Livingstone Fault; the recently active Auckland Volcanic Field is similarly located along-strike on North Island. We suggest that the Livingstone Fault controlled the location of the Tuatara Volcanic Field by producing relief at the base of the lithosphere, thereby focussing lithospheric detachment over c. 40 myr, and provided a pathway that facilitated the ascent of magma. We highlight how observations from ancient intraplate volcanic systems may inform our understanding of active intraplate volcanic systems, including the Auckland Volcanic Field
Relative Roles of Medical Interventions and Infrastructure in an Urban Community’s Infant Mortality Rate: 100 Years of Infant Mortality in the City of Worcester
Background: The infant mortality rate (IMR), defined as the number of deaths in children under 1 year of age per 1000 live births, is regarded as a sensitive measure of population health (Blaxter). This reflects the overlap between those societal factors that impact infant mortality and those that affect the health of the larger community, such as SES, nutrition, living conditions, education, employment and access to health care. In 2003, Reidpath et al showed a strong linear relation between IMR and the disability adjusted life expectancy (DALE), a more comprehensive measure of population health. They concluded that either the IMR or the DALE could stand as a proxy for the measurement of population health.
Objectives: We proposed to study historic trends in the IMR of the city of Worcester, MA, the second largest city in New England with a population of 181,045 (census 2010), over a 100 year period. We evaluated trends in the overall infant mortality rate as well as by specific causes of death. We further looked at known changes in medical innovation as well as community living conditions that may have had an effect on these rates.
Methods: From August through September 2012, infant death certificates housed in the Worcester City Hall, Office of the City Clerk, were reviewed and entered into an Excel spreadsheet. The first year, 1906, was selected due to a particularly high IMR. Following 1906, years were chosen at 10-year intervals through 1976. Beginning in 1986, data was available through a downloadable file. Data collected included the record number, the date of death, the age of the infant in months and years, cause of death, city of residence, and place of birth of mother. Specific causes of death were transformed into 13 general categories. A subsequent comparative analysis was performed.
Results: A total of 2929 hard copy death certificates were reviewed and an additional 116 records were added through downloadable files. Because 1956 was the last year to include stillbirth in infant mortality records, analysis was conducted excluding numbers of stillbirths. In 1906, the overall IMR was 143 (per 1000 live births). By 1936, the total IMR had already dropped significantly to 52, a drop of 64%. By 2006, the IMR had dropped to 4.6, a decrease of almost 97%. Much of this drop reflected changes in the IMR due to infection, which dropped from 75 in 1906 to 15 in 1936 and to .4 by 2006. In total, the decrease in IMR due to infection was responsible for more than half of the total decrease in IMR, with 80% of the drop in infection-related IMR occurring before 1936. Over this time period, the IMR due to congenital malformations also slowly decreased from 8 in 1906, to 7.3 in 1976 and then to 2.0 in 1986 and .8 in 2006. Interestingly, 83% of the decreases in IMR due to malformation occurred after 1976. IMR due to prematurity was 34 in 1906, decreased to 14.7 in 1976 and further decreased to 6.4 in 1986 and to 3.1 in 2006. Again, 89% of the decreases in IMR due to prematurity occurred after 1976.
Conclusions: The IMR in Worcester has undergone a dramatic reduction over the past 100 years, driven in large part by great reductions in number of deaths from infectious causes. Interestingly, a large part of the reduction in IMR secondary to infection occurred by 1936, prior to the development and widespread availability of antibiotics and vaccines against infectious diseases starting in the 1940s. Changes in public health infrastructure, changes in hygiene, including water, sewage and housing, and access to better nutrition and education likely played a significant role in decreased infant mortality due to infection prior to the development of medical interventions. A number of medical developments are likely responsible for decreased rates of infant mortality due to malformations and prematurity seen after 1976. These include the advent of neonatal surgery in the 1950s, the introduction of Neonatal Intensive Care Units (NICUs) in the 1960s, the use of fetal heart monitors and fetal distress as an indication for delivery by cesarean section in the 1960s to 1970s, the development of amniocentesis (for lung maturity and genetic testing) and ultrasound (for dating) in the 1970s, Roe vs. Wade in 1973, the advent of alpha fetoprotein testing and folic acid supplementation in the 1980s, and corticosteroids for fetal lung maturity in the 1980s-1990s. The large decrease in IMR due to infectious causes over the last 100 years highlights IMR’s sensitive relationship to societal factors and suggests that deteriorations in living conditions during recent difficult economic times could result in high and increasing IMRs among vulnerable subpopulations. We propose that interventions addressing societal factors could have the greatest impact in preventing infant mortality in Worcester
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