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Posts Tagged ‘SIAM Journals’

Bayesian Model Improves Use of X-ray Radiography in National Security

Quantitative radiography is an imaging technique that uses electromagnetic radiation, such as X-rays, to gather quantitative data about the interior of nontransparent objects that vary in density and composition. For example, radiography is particularly helpful when reconstructing objects composed of multiple materials, such as different types of metal. In order to generate these images, most high-energy technologies pulse X-rays through the “scene” in question; objects in the scene absorb some of the rays, while a scintillator – which measures the strength of the passing X-rays – collects the rest and fluoresces (emits visible light) in response to the collected rays. Possible scenes include parts of the human body, thermal explosions, nuclear testing sites, and other applications of national security. The resulting images directly measure the intensity of visible light, yielding information about the objects’ internal structure.

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Equilibrium Modeling Increases Contact Lens Comfort

According to the Vision Council of America, roughly 75% of adults in the United States require some form of vision correction. Yet only 10% of Americans wear contact lenses. Studies estimate that one in four initial contact-users finds the lenses uncomfortable and stops wearing them. Thus, increasing the comfort level of contact lenses and expanding the market is a continual objective in the vision industry.

In order to understand the factors that contribute to lens comfort, it is important to study the solid and fluid mechanics of a lens’ interaction with an eye. In an article publishing this week in the SIAM Journal on Applied Mathematics, authors David Ross, Kara Maki, and Emily Holz design an equilibrium model to demonstrate the elastic stresses and suction pressure distribution between a soft hydrogel contact lens and an eye. Read the rest of this entry »

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Segmenting Ultrasound Video with a Wavelet Variational Model

Image segmentation, the process of separating a digital image into multiple sections for individual examination, is frequently used in medical image analysis. For example, segmentation in ultrasound footage helps identify boundaries and regions of interest (ROI) that facilitate image interpretation. Efficient segmentation of ultrasound videos, however, is often complicated by low contrast, shadow effects, and complex “noise” statistics (unexplained variations). In addition, real-time applications such as navigation during operational surgery require efficient algorithms.

In an article published this month in the SIAM Journal on Imaging Sciences, authors Jiulong Liu, Xiaoqun Zhang, Bin Dong, Zuowei Shen, and Lixu Gu propose a video segmentation model to recognize ROI in ultrasounds. Read the rest of this entry »

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Applying Parameter Selection and Verification Techniques to an HIV Model

Physical and biological models often have hundreds of inputs, many of which may have a negligible effect on a model’s response. Establishing parameters that can be fixed at nominal values without significantly affecting model outputs is often difficult; sometimes these parameters cannot be simply discerned by the outputs. Thus, verifying that a parameter is noninfluential is both computationally challenging and quite expensive. Read the rest of this entry »

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Q&A: Tamara Kolda on SIAM Journal Macro Update

In January, SIAM introduced a substantially updated macro set for 11 of our journals, with a corresponding upgrade to our four exclusively online journals to follow. This development was the work of a committee under the leadership of Tamara G. Kolda of Sandia National Laboratories. We sat down with Tammy to find out what the update will mean for SIAM journal authors and readers. Read the rest of this entry »

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SIAM Manuscripts Enhanced Due to Modernized Macros

Last month, SIAM released a significantly modernized set of LaTeX2e Macro files for use with 11 of our journals. A corresponding upgrade to macros for our four (soon to be five) exclusively online journals will follow. Read the rest of this entry »

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Nugget: Improving Electric Motor Efficiency Via Shape Optimization

Philadelphia, PA – In our competitive global society, successful and economical design of automotive and industrial structures is crucial. Optimizing the geometry of individual pieces of complex machines improves performance and efficiency of the entire device.

To achieve this, the automotive and aeronautic industries often rely on shape optimization, an approach that uses modeling to create a framework for making devices as smooth and efficient as possible. “A smoother rotation of the rotor can increase the energy efficiency of the motor, and at the same time reduce unwanted side effects like noise and vibrations,” says mathematician Ulrich Langer. Read the rest of this entry »

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Supplementary Materials for SIAM journals

SIAM journals have entered a new era and are now considering unrefereed supplementary materials for publication along with the author’s manuscript. The first journals to seize the opportunity, SIAM Journal on Matrix Analysis and Applications, SIAM Journal on Scientific Computing and SIAM Review, began taking submissions with accompanying supplemental files in January.  SIAM Journal on Mathematical Analysis is next in line, with other journals expected to follow.

Prior to this new initiative, SIAM Journal on Applied Dynamical Systems and SIAM Journal on Imaging Sciences did review refereed supplemental content. SIAM journals that consider supplemental content for publication under the new policy will treat it on an unrefereed basis.

Supplementary materials must be submitted at the same time the article is first submitted. They might include additional figures or examples, animations, data sets used in the paper, computer code used to generate figures or tables, or other materials that are necessary to fully document the research contained in the paper or to facilitate the readers’ ability to understand and extend the work.

Supplementary materials, though not refereed, will be available to referees. The referees will be asked to give the materials at least a cursory look and verify that they are appropriate to accompany the paper. The referees or editor may suggest changes.

If published, they will be linked from the main article webpage and will be clearly marked as unrefereed supplementary materials associated with a particular paper.

 

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A math-based model for deep-water oil drilling

Oil well control is one of the most important processes during drilling operations. In deepwater drilling, controlling pressure in the oil well is crucial, as excessive pressures in the drilled hole can result in blowouts, leading to disastrous events like the 2010 Gulf of Mexico Oil Spill.

The deeper the well, the higher the pressure, and the higher the risks associated with tapping oil from wells. During drilling, when the pressure applied to balance the hydrocarbon pressure in a well is not great enough to overcome that exerted by gas and fluids in the rock formation drilled, water, gas, oil, or other formation fluid can enter the hole. This is called a “gas kick,” which in worst-case scenarios can lead to blowouts.

In a paper published earlier this month in the SIAM Journal on Mathematical Analysis, author Steinar Evje presents new analysis of a mathematical model that has applications to the study of such gas kicks in deep-water oil wells. Read the rest of this entry »

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