Non-standard Techniques Research Articles

“All the Bright Eyes of the Kingdom”: Charlotte Lennox's Discursive Communities

This article argues that Charlotte Lennox innovates with nonstandard narrative techniques to conjure up lively new discursive communities. In her most famous work, The Female Quixote (1752), Lennox experiments with the formal feature of chapter titles, whose insouciant, disembodied voice emerges as the text's most distinct and powerful narrative force. This voice presents itself as corrective and collective, demonstrating the benefits of a community and redefining the authority of the author. In her less well-known periodical, The Lady's Museum (1760-61), Lennox introduces an eidolon, “The Trifler,” whose lively voice recalls The Female Quixote's chapter titles. As the periodical continues, the Trifler's individual voice gives way to an even livelier assortment of voices, which debate the Trifler's right to her “title”. In both works, Lennox explores the tension between instruction and delight. Her writing offers far more than a straightforward, laudable project of female education, as she imagines pleasing discursive communities in which meaning in general, and “titles” in particular, are debated, challenged, and in flux.

Large Deviations for Stationary Measures of Stochastic Nonlinear Wave Equations\\with Smooth White Noise

The paper is devoted to the derivation of the large deviations principle for the family of stationary measures of the Markov process generated by the flow of the damped nonlinear wave equations with vanishing white noise. One of the main novelties here is that we do not assume that the deterministic equation possesses a unique equilibrium and we do not impose roughness on the noise. We introduce a new mathematical tool called the generalized stationary measure, which, informally speaking, is a stationary measure that is not necessarily σ‐additive. We show that any Markov operator admits such a measure and use this to develop the Freidlin‐Wentzell and Khasminskii approaches to the infinite‐dimensional setting. We also extend Sowers' method when establishing exponential tightness. Some ingredients of the proof rely on rather nonstandard techniques.© 2017 Wiley Periodicals, Inc.

Can Pre-Retrieval Computed Tomography Predict the Difficult Removal of an Implementing an Inferior Vena Cava Filter?

Purpose:Implementing an inferior vena cava (IVC) filter is a relatively safe procedure but potential negative long-term effects. The complications for filter retrieval have been noted. We examined filter characteristics on pre-retrieval computed tomography (CT) that were associated with complicated retrieval (CR) of IVC filters.Materials and Methods:A retrospective review of IVC filter retrievals between January 2008 and June 2014 was performed to identify patients who had undergone a pre-retrieval CT for IVC filter retrieval. CR was defined as the use of nonstandard techniques, procedural time over 30 min, filter fractures, filter tip incorporation into the IVC wall, and retrieval failure. Pre-retrieval CT images were evaluated for tilt angle in the mediolateral and anteroposterior directions, tip embedding into the IVC wall, degree of filter strut perforation, and distance of the filter tip from the nearest renal vein.Results:Of seventy-six patients, twenty-four patients (31.6%) with CRs and 56 patients (73.7%) with non-CR were evaluated for pre-retrieval CT. For IVC filter retrieval with a dwelling time of over 45 days, a tilt of over 15 degrees, the appearance of tip embedding and grade 2 perforation were associated with CR on multivariate analysis. However, for IVC filter retrievals with a dwelling time of less than 45 days, there were no factors associated with CR.Conclusion:Pre-retrieval CTs may be more effective for IVC filters with a dwelling time of over 45 days. Therefore, a pre-retrieval CT may be helpful in predicting CR of IVC filters with long dwelling times.

Validation of material constitutive parameters for the AISI 1010 steel from Taylor impact tests

Numerical simulations of high strain-rate events require robust characterization of constitutive material parameters in order to predict accurately the deformation process. Historically, this characterization has been performed using non-standardized techniques such as the Taylor impact test, where specimen's final deformed geometry is used to determine the material constitutive parameters by inverse analysis. However, validation of material parameters found in this way, in terms of internal plastic strains, is an open research problem. In this work, material constitutive parameters of steel AISI 1010 found by inverse analysis from Taylor tests at ~5×103s−1 were validated. This was done by comparing the Vickers hardness profile along the axis of a deformed specimen against the numerically calculated hardness from a finite element model of the Taylor impact, which used the constitutive parameters found by inverse analysis. To map the simulated effective plastic strains found in the model into Vickers hardness, an experimentally-derived analytical relation between compressive quasi-static plastic strains and Vickers hardness on cylinders of the same material was used. It was found that the material constitutive parameters of steel AISI 1010 characterized by inverse analysis, from silhouettes of deformed Taylor tests, are capable to predict the plastic-strain distribution inside the deformed material.

Disproportionate Collapse Simulations

In recent years the ability to simulate and predict disproportionate collapse has seen growing interest among the scientific community. This is a challenging matter, since many authors have been dealing with the modeling of progressive collapse, and it is now well-established that such problem requires the use of many different non-standard modeling techniques together with extensive calibration. Despite the many papers in the literature, there is still a lack of methodologies tailored for the quantification of the structural robustness and its acceptable level, which clearly depends on the importance and function of the structure. Further, consideration of Performance Criteria as well as Decision Making Strategies, have to be supported by robust (but also efficient) modeling methods that have to include three-dimensional and geometrical non-linear effects. Some of the previously outlined principles about robustness will be discussed following which the authors present a methodology for taking into account that progressive collapse phenomena are governed not only by the dynamic response of the bays adjacent to the triggering event, but also by the residual plastic resources the structure conserves after the initial damage.

A Hybridizable Discontinuous Galerkin Method for the Time-Harmonic Maxwell Equations with High Wave Number

Abstract This paper proposes and analyzes a hybridizable discontinuous Galerkin (HDG) method for the three-dimensional time-harmonic Maxwell equations coupled with the impedance boundary condition in the case of high wave number. It is proved that the HDG method is absolutely stable for all wave numbers κ > 0 ${\kappa>0}$ in the sense that no mesh constraint is required for the stability. A wave-number-explicit stability constant is also obtained. This is done by choosing a specific penalty parameter and using a PDE duality argument. Utilizing the stability estimate and a non-standard technique, the error estimates in both the energy-norm and the 𝐋 2 ${\mathbf{L}^{2}}$ -norm are obtained for the HDG method. Numerical experiments are provided to validate the theoretical results and to gauge the performance of the proposed HDG method.

Investigation of the pollution in the street dust at Xuzhou, China, using magnetic, micro-morphological and Mössbauer spectra analyses

This study reports a detailed examination of the magnetic mineralogy of street dust samples collected in Xuzhou, a heavily industrial city in China. Several different approaches have been utilized in the characterization, from standard mineral magnetic techniques such as magnetic hysteresis and microscopy to non-standard techniques such as Mossbauer spectroscopy. Magnetic properties and the concentrations of four metals including Cu, Zn, Ba and Pb were reported for each sample. The primary magnetic mineral was found to be multidomain magnetite-like material. Scanning electron microscope analyses of street dust revealed: spherule-shaped iron oxides and angular particles with complex chemical composition. The concentrations of Cu, Zn, Pb and Ba were 3, 4.8, 2.8 and 1.3 times higher, respectively, than the soil background values of this study area. Both Cu and Ba showed significant correlations with the magnetic concentration parameters χARM (susceptibility of anhysteretic remanent magnetization) and saturation isothermal remanent magnetization. The combination of the various methods offers a powerful analytical technique in the study of magnetic properties of street dust.

Single Surgeon Experience With Minimally Invasive AVR: Expectations of a Change in Practice

Reports of minimally invasive aortic valve replacement (miniAVR) are hampered by non-standardized techniques and multi-surgeon/institution practice.

Geosystems as an alternative to conventional coastal defense

In recent decades, the increase in population on the coast, growth of erosion in many coastal stretches and the sea level rise, due to climate change, have led governments to invest more in protecting the coast. Geosystems have been shown as an alternative to conventional coastal structures because of cost reduction, efficiency of construction and speed of implementation. However this alternative leads to increase knowledge in their behavior, design and durability by the lack of suitable materials to withstand large storms, high diversity of non-standard methods or techniques and ease of degradation by vandalism.

Integration through a Card-Sort Activity

Learning to compute integrals via the various techniques of integration (e.g., integration by parts, partial fractions, etc.) is difficult for many students. Here, we look at how students in a college level Calculus II course develop the ability to categorize integrals and the difficulties they encounter using a card sort-resort activity. Analysis of the data required the use of several non-standard techniques which provided interesting insights into the ways students develop categories in mathematics. One finding of note is that students may need a significant amount of time “off topic” to allow sufficient time to fully organize their schema for integration.

Coupling finite volume and nonstandard finite difference schemes for a singularly perturbed Schrödinger equation

The Schrödinger equation is a model for many physical processes in quantum physics. It is a singularly perturbed differential equation where the presence of the small reduced Planck's constant makes the classical numerical methods very costly and inefficient. We design two new schemes. The first scheme is the nonstandard finite volume method, whereby the perturbation term is approximated by nonstandard technique, the potential is approximated by its mean value on the cell and the complex dependent boundary conditions are handled by exact schemes. In the second scheme, the deficiency of classical schemes is corrected by the inner expansion in the boundary layer region. Numerical simulations supporting the performance of the schemes are presented.

SUSY Searches in the ATLAS Experiment

Recent results from the ATLAS experiment at the LHC in the search for supersymmetry are presented. A focus is placed on searches requiring nonstandard techniques in particularly challenging final states. All searches presented here analyze pp collisions with √s = 8 TeV collected in 2012. Within these results, in the absence of significant disagreement from the Standard Model expectations, limits are placed on various models in both strong and weak sparticle production as well as on models with long-lived sparticles.

A nonstandard technique in combinatorial number theory

In Di Nasso (2015) and Luperi Baglini (2012) it has been introduced a technique, based on nonstandard analysis, to study some problems in combinatorial number theory. In this paper we review such a technique and we present three of its applications: the first one is a new proof of a known result regarding the algebra of βN, namely that the center of the semigroup (βN,⊕) is N; the second one is a generalization of a theorem of Bergelson and Hindman on arithmetic progressions of length three; the third one regards the study of which polynomials in several variables with integers coefficients have a monochromatic solution for every finite coloring of N. We will study this last application in more detail: we will prove some algebraical properties of the set P of such polynomials and we will present a few examples of nonlinear polynomials in P.In the first part of the paper we will recall the main results of the nonstandard technique that we want to use, which is based on a characterization of ultrafilters by means of nonstandard analysis.

Sketching Sparse Matrices, Covariances, and Graphs via Tensor Products

This paper considers the problem of recovering an unknown sparse p×p matrix X from an m×m matrix Y=AXB T , where A and B are known m×p matrices with m≪p. The main result shows that there exist constructions of the sketching matrices A and B so that even if X has O(p) nonzeros, it can be recovered exactly and efficiently using a convex program as long as these nonzeros are not concentrated in any single row/column of X. Furthermore, it suffices for the size of Y (the sketch dimension) to scale as m = O(√(# nonzeros in X) × log p). The results also show that the recovery is robust and stable in the sense that if X is equal to a sparse matrix plus a perturbation, then the convex program we propose produces an approximation with accuracy proportional to the size of the perturbation. Unlike traditional results on sparse recovery, where the sensing matrix produces independent measurements, our sensing operator is highly constrained (it assumes a tensor product structure). Therefore, proving recovery guarantees require nonstandard techniques. Indeed, our approach relies on a novel result concerning tensor products of bipartite graphs, which may be of independent interest. This problem is motivated by the following application, among others. Consider a p×n data matrix D, consisting of n observations of p variables. Assume that the correlation matrix X:=DD T is (approximately) sparse in the sense that each of the p variables is significantly correlated with only a few others. Our results show that these significant correlations can be detected even if we have access to only a sketch of the data S=AD with A ∈ R m×p .

Relationship between 1:5 Soil/Water and Saturated Paste Extract Sodium Adsorption Ratios by Three Extraction Methods

Cations extracted from soil using non-standard techniques are used to calculate the sodium adsorption ratio (SAR). To interpret these values, analytical approaches for converting alternative approaches to standard approaches are needed. The objective of this research was to develop the relationship between the standard approach (saturated paste extract, SARe) and alternative approaches where the cations are in 1: 5 soil/water ratios and are mixed by shaking, stirring, or an NRCS method (allowed to reach equilibrium). One hundred soils sampled from glacial parent materials in North Dakota were selected for this study. The SAR values from the three methods were highly correlated to each other. Simple linear regression (Model 1), robust regression, and Model 2 were analyzed for the relationship between SAR1:5 and SARe. Outlier analysis and calcite content distribution indicated the possible influence of calcite content. The soil data were classified into high and low calcite by a 4.2% criterion. In addition, Ca in the 1:5 and saturated paste extracts showed poor relationships, also indicating that Ca had an influence. Model 1 and robust regression were similar in expressing the relationship between soil SAR1:5 and SARe with a normal residual distribution, but Model 2 had high left skewness in the residual distribution. The model prediction was increased when soil data were classified by calcite content. Predicting the SARe of soils from SAR1:5 data is possible but soil-calcite concentrations should be considered; 1:5 methods can confidently be compared.

ON THE ACCURACY OFHIPPARCOSUSING BINARY STARS AS A CALIBRATION TOOL

Stellar binary systems, specifically those that present the most accurate available orbital elements, are a reliable tool to test the accuracy of astrometric observations. We selected all 35 binaries with these characteristics. Our objective is to provide standard uncertainties for the positions and parallaxes measured by Hipparcos relative to this trustworthy set, as well as to check supposed correlations between several parameters (measurement residuals, positions, magnitudes, and parallaxes). In addition, using the high-confidence subset of visual–spectroscopic binaries, we implemented a validation test of the Hipparcos trigonometric parallaxes of binary systems that allowed the evaluation of their reliability. Standard and non-standard statistical analysis techniques were applied in order to achieve well-founded conclusions. In particular, errors-in-variables models such as the total least-squares method were used to validate Hipparcos parallaxes by comparison with those obtained directly from the orbital elements. Previously, we executed Thompsonʼs τ technique in order to detect suspected outliers in the data. Furthermore, several statistical hypothesis tests were carried out to verify if our results were statistically significant. A statistically significant trend indicating larger Hipparcos angular separations with respect to the reference values in 5.2 ± 1.4 mas was found at the 10−8 significance level. Uncertainties in the polar coordinates θ and ρ of 1.°8 and 6.3 mas, respectively, were estimated for the Hipparcos observations of binary systems. We also verified that the parallaxes of binary systems measured in this mission are absolutely compatible with the set of orbital parallaxes obtained from the most accurate orbits at least at the 95% confidence level. This methodology allows us to better estimate the accuracy of Hipparcos observations of binary systems. Indeed, further application to the data collected by Gaia should yield a standard procedure to compare both data sets.

Synchronous Ventral Hernia Repair in Bariatric Patients

Dear Editor, We note with interest the article of Eid et al. [1] and correspondence in the journal recently on the topic issue of timing of ventral hernia in bariatric patients. We note that this correspondence recommends a range of options in managing these patients but provides little evidence to back up these recommendations. While the issue of ventral hernia is obviously complex, we are concerned that recommending non-standard treatments may lead to outcomes that expose patients to increased risks and repeated surgical procedures. The use of suture and absorbable mesh repairs have been shown to have high recurrence rates, and leaving hernias untreated will expose patients to the certain requirement for later surgery and the risks of small bowel obstruction associated with their rapid weight loss. With this consideration, we consider all patients undergoing bariatric procedures with ventral hernias as candidates for synchronous repair, unless they had massive abdominal wall defects or cutaneous redundancy, in which case they are usually offered sleeve gastrectomy followed by delayed abdominal wall reconstruction. This number is small. We have attempted to answer the question of whether patients having bariatric surgery can have simultaneous ventral hernia repair if it is felt that the defect is amenable to laparoscopic repair by studying our outcomes [2]. In our series of 45 patients undergoing synchronous bariatric surgery and ventral hernia repair, the results were similar to those of laparoscopic repair alone. Two patients developed infected seromas that responded to simple drainage, and there have been no mesh removals or clinical hernia recurrence to date. This fits with the results of a Cochrane review comparing open and laparoscopic techniques concluding that laparoscopic hernia repair infection rates were 3.14 % (range 0–6.06 %) [3]. While valid concerns exist about the potential complication rate of using permanent mesh in patients having bariatric surgery, the rate of complications appear reassuringly low. Surgeons can be comfortable making decisions based on data, and in this situation, these data suggest that patients presenting for bariatric surgery with concomitant hernia can be offered standard treatment with the expectation of standard outcomes. The outcomes of non-standardised techniques such as suture repair or using biologics are poorly known, and since these repairs are either more likely to fail or are more complex than usual laparoscopic repair methods, they are hard to recommend in the face of established safe and effective techniques. In the future, a multicentre study may be able to provide sufficient numbers for a case-control or randomised trial, but until this occurs, clinicians must incorporate current evidence through available case-series, experience and extrapolation from published trials of established techniques.

Imaging Presentations of Spinal Instability

: Low back pain is a common condition with a lifetime prevalence of up to 84% in the general population. In many cases it remains difficult to determine the exact cause of back pain, but among various other conditions, lumbar instability is important. Spinal instability is defined as an abnormal response to applied loads, characterized by movement in the motion segment beyond normal constraints. The etiologies of spinal instability can be classified as congenital (dysplastic), spondylolytic (isthmic), degenerative, traumatic, pathologic and iatrogenic (i.e., postoperative). The diagnosis of intervertebral instability is based on the direct and indirect radiological findings of an abnormal vertebral motion. A variety of imaging modalities are currently used to assess spinal instability with each having its merits and demerits. Plain radiographs are the baseline investigation but have uncertain diagnostic value as they show only indirect evidences of spinal instability. Functional radiography is promising; however, it has its limitations of inaccurate reproducibility and non-standardized techniques. Computed tomography offers a higher sensitivity than plain radiographs due to its superior contrast resolution and better delineation of bony structures. Functional CT illustrates abnormal motion between the facet joints and objectively establishes spinal instability. MR imaging is highly sensitive in detection of soft tissue abnormalities that contribute to spinal instability. Analysis of the various imaging modalities reveal that no single modality is complete by itself and needs to be complemented by other.

Nonstandard second-order arithmetic and Riemannʼs mapping theorem

In this paper, we introduce systems of nonstandard second-order arithmetic which are conservative extensions of systems of second-order arithmetic. Within these systems, we do reverse mathematics for nonstandard analysis, and we can import techniques of nonstandard analysis into analysis in weak systems of second-order arithmetic. Then, we apply nonstandard techniques to a version of Riemannʼs mapping theorem, and show several different versions of Riemannʼs mapping theorem.

Sa1398 Submucosal Injection Pressure in the Upper Gastrointestinal Tract

Endoscopic injection has different uses, endoscopist controls site of injection and an assistant “feels” the resistance applied, in a non-standardized technique. Moreover between anesthesiologist injection pressure for peripheral blockade has not correlation, now includes controled pressure techniques, as well as in Radiology, Oftalmology, Reumatology, decreasing operators variability. In Endoscopy measure of injection pressure is referred for endoscopic mucosal resection and submucosal dissection, in studies about injectable solutions kinds as objetive.Objetives: To determine the injection pressure in ex vivo porcine esophagus and stomach submucosa, and evaluate differences between the pressures of their anatomical regions.Justification: Determine objectively the injection pressure as a tool that could facilitate the technical and reduce variability between operators.