2,444 research outputs found
Hybrid perturbation/Bubnov-Galerkin technique for nonlinear thermal analysis
A two step hybrid analysis technique to predict the nonlinear steady state temperature distribution in structures and solids is presented. The technique is based on the regular perturbation expansion and the classical Bubnov-Galerkin approximation. The functions are obtained by using the regular perturbation method. These functions are selected as coordinate functions and the classical Bubnov-Galerkin technique is used to compute their amplitudes. The potential of the proposed hybrid technique for the solution of nonlinear thermal problems is discussed. The effectiveness of this technique is demonstrated by the effects of conduction, convection, and radiation modes of heat transfer. It is indicated that the hybrid technique overcomes the two major drawbacks of the classical techniques: (1) the requirement of using a small parameter in the regular perturbation method; and (2) the arbitrariness in the choice of the coordinate functions in the Bubnov-Galerkin technique. The proposed technique extends the range of applicability of the regular perturbation method and enhances the effectiveness of the Bubnov-Galerkin technique
Laboratory observations of midwater spawning by Illex illecebrosus
Visual observations and video-tape records were made for the first time of mid-water spawning by Illex illecebrosus in the Aquatron Laboratory pool tank. Coupled with data on the density of egg masses, they allow some conclusions to be drawn concerning possible mid-water spawning sites in nature
ââThereâs so much more to it than what I initially thoughtââ: Stepping into researchersâ shoes with a class activity in a first year psychology survey course
In psychology, it is widely agreed that research methods, although central to the discipline, are particularly challenging to learn and teach, particularly at introductory level. This pilot study explored the potential of embedding a student-conducted research activity in a one-semester undergraduate Introduction to Psychology survey course, with the aims of (a) engaging students with the topic of research methods; (b) developing studentsâ comprehension and application of research methods concepts; and (c) building studentsâ ability to link research with theory. The research activity explored shoe ownership, examining gender differences and relationships with age, and linking to theories of gender difference and of consumer identity. The process of carrying out the research and reflecting on it created a contextualized, active learning environment in which students themselves raised many issues that research methods lectures seek to cover. Students also wrote richer assignments than standard first year mid-term essay
Differentially Private Synthetic Data Using KD-Trees
Creation of a synthetic dataset that faithfully represents the data
distribution and simultaneously preserves privacy is a major research
challenge. Many space partitioning based approaches have emerged in recent
years for answering statistical queries in a differentially private manner.
However, for synthetic data generation problem, recent research has been mainly
focused on deep generative models. In contrast, we exploit space partitioning
techniques together with noise perturbation and thus achieve intuitive and
transparent algorithms. We propose both data independent and data dependent
algorithms for -differentially private synthetic data generation
whose kernel density resembles that of the real dataset. Additionally, we
provide theoretical results on the utility-privacy trade-offs and show how our
data dependent approach overcomes the curse of dimensionality and leads to a
scalable algorithm. We show empirical utility improvements over the prior work,
and discuss performance of our algorithm on a downstream classification task on
a real dataset
Suicide: A Constitutional Right?
Recent advocacy of a right to suicide raises the question of whether statutes which penalize the assistance of suicide and the widespread practice of intervention to stop suicide attempts are unconstitutional. This article considers the claim that the right of privacy or substantive due process encompasses autonomy to do whatever affects no one else, and concludes that the Supreme Court has recognized only those forms of autonomy that it has deemed to be rooted in the traditions and history of our society. After outlining the attitudes toward suicide at various stages in Western Civilization, focusing on Anglo- American history and particularly on the legal tradition, the authors conclude that the predominant approach has been to discourage suicide and to penalize its assistance, while, at least in American history, to treat rather than condemn the suicide attempter. In their view, suicide has not historically been treated as a fundamental right. The article then relates psychological and sociological evidence that those who attempt suicide are normally ambivalent, usually do so for reasons other than a settled desire to die, and are predominantly the victims of mental disorder. Finally, the authors argue that societal sanctions for suicide would lead to manipulation by others and social pressure that would induce many unstable individuals, who would otherwise be helped, to commit suicide. For these reasons, the authors regard recognition of a right to suicide as unjustified and undesirable
Simulation Approach for Timing Analysis of Genetic Logic Circuits
Constructing
genetic logic circuits is an application of synthetic
biology in which parts of the DNA of a living cell are engineered
to perform a dedicated Boolean function triggered by an appropriate
concentration of certain proteins or by different genetic components.
These logic circuits work in a manner similar to electronic logic
circuits, but they are much more stochastic and hence much harder
to characterize. In this article, we introduce an approach to analyze
the threshold value and timing of genetic logic circuits. We show
how this approach can be used to analyze the timing behavior of single
and cascaded genetic logic circuits. We further analyze the timing
sensitivity of circuits by varying the degradation rates and concentrations.
Our approach can be used not only to characterize the timing behavior
but also to analyze the timing constraints of cascaded genetic logic
circuits, a capability that we believe will be important for design
automation in synthetic biology
Hormone replacement therapy after surgery for stage 1 or 2 cutaneous melanoma
A total of 206 women were followed for a minimum of 5 years after primary melanoma surgery to establish if hormone replacement therapy (HRT) adversely affected prognosis. In all, 123 had no HRT and 22 have died of melanoma; 83 had HRT for varying periods and one has died of melanoma. After controlling for known prognostic factors, we conclude that HRT after melanoma does not adversely affect prognosis
Properties of IIlex illecebrosus Egg Masses Potentially Influencing larval Oceanographic Distribution
Visual observations and video-tape records of the spawning of captive IIlex illecebrosus show that this species can produce gelatinous egg masses 50 cm or larger in diameter while swimming in open water. Measurements of the density of the eggs and the changes in water density which are necessary to lift egg masses indicate that the masses have densities about 0.005% greater than the water used to make the gel, whereas the eggs are more than 5% denser than typical seawater. The gel thus appears to function as a buoyancy mechanism which prevents eggs from sinking. Measurements of rates of temperature equilibration between egg masses and the surrounding water indicate that complete density equilibration requires many days under most conditions. If spawning occurs pelagically, common oceanographic situations where density increases with depth, due either to decreasing temperature (e.g. North Atlantic Central Water) or increasing salinity (e.g. the Gulf Stream), could allow the egg masses to be suspended in the mesopelagic zone. Such a mechanism, which could retain pelagically-spawned eggs of IIlex and other oegopsids, particularly ommastrephids, in a zone where temperatures are adequate to allow embryonic development, helps to explain why there are so few records of ommastrephid eggs in nature
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