Toward a mathematical theory of perception

A new technique for the modelling of perceptual systems called formal modelling is developed. This technique begins with qualitative observations about the perceptual system, the so-called perceptual symmetries, to obtain through mathematical analysis certain model structures which may then be calibrated by experiment. The analysis proceeds in two different ways depending upon the choice of linear or nonlinear models. For the linear case, the analysis proceeds through the methods of unitary representation theory. It begins with a unitary group representation on the image space and produces what we have called the fundamental structure theorem. For the nonlinear case, the analysis makes essential use of infinite-dimensional manifold theory. It begins with a Lie group action on an image manifold and produces the fundamental structure formula. These techniques will be used to study the brightness perception mechanism of the human visual system. Several visual groups are defined and their corresponding structures for visual system models are obtained. A new transform called the Mandala transform will be deduced from a certain visual group and its implications for image processing will be discussed. Several new phenomena of brightness perception will be presented. New facts about the Mach band illusion along with new adaptation phenomena will be presented. Also a new visual illusion will be presented. A visual model based on the above techniques will be presented. It will also be shown how use of statistical estimation theory can be made in the study of contrast adaptation. Furthermore, a mathematical interpretation of unconscious inference and a simple explanation of the Tolhurst effect without mutual channel inhibition will be given. Finally, image processing algorithms suggested by the model will be used to process a real-world image for enhancement and for "form" and texture extraction

Filtering high quality text for display on raster scan devices

Recently several investigators have studied the problem of displaying text characters on grey level raster scan displays. Despite arguments suggesting that grey level displays are equivalent to very high resolution bitmaps, the performance of grey level displays has been disappointing. this paper will show that much of the problem can be traced to inappropriate antialiasing procedures. Instead of the classical (sin x)/x filter, the situation calls for a filter with characteristics matched both to the nature of display on CRTs and to the human visual system. We give examples to illustrate the problems of the existing methods and the advantages of the new methods. Although the techniques are described in terms of text, the results have application to the general antialiasing problem--at least in theory if not practice

Differential pharmacology and benefit/risk of azilsartan compared to other sartans

Azilsartan, an angiotensin II type 1 (AT1) receptor blocker (ARB), was recently approved by regulatory authorities for treatment of hypertension and is the 8th ARB to join the clinical market. This article discusses the medical reasons for introducing a new AT1 receptor blocker and reviews the experimental and clinical studies that have compared the functional properties of azilsartan to those of other ARBs. The main question addressed is: Does azilsartan have distinguishing features that should motivate choosing it over any of the other sartans for use in clinical practice? Based on studies conducted to date in hypertensive patients without serious comorbidities, azilsartan appears to be characterized by a superior ability to control 24-hour systolic blood pressure (BP) relative to other widely used ARBs including valsartan, olmesartan, and candesartan, and presumably others as well (eg, losartan). Compared to these other ARBs, azilsartan may increase the BP target control and response rate by an absolute value of 8%–10%. Greater antihypertensive effects of azilsartan might be due in part to its unusually potent and persistent ability to inhibit binding of angiotensin II to AT1 receptors. Preclinical studies have indicated that azilsartan may also have potentially beneficial effects on cellular mechanisms of cardiometabolic disease and insulin sensitizing activity that could involve more than just blockade of AT1 receptors and/or reduction in BP. However, the clinical relevance of these additional actions is unknown. Given that the general ability of antihypertensive drugs to protect against target organ damage is largely mediated by their ability to decrease BP, the enhanced antihypertensive effects of azilsartan should serve to justify clinical interest in this ARB relative to other molecules in the class that have a lower capacity to reduce BP

Quantum error correction beyond qubits

Quantum computation and communication rely on the ability to manipulate quantum states robustly and with high fidelity. Thus, some form of error correction is needed to protect fragile quantum superposition states from corruption by so-called decoherence noise. Indeed, the discovery of quantum error correction (QEC) turned the field of quantum information from an academic curiosity into a developing technology. Here we present a continuous-variable experimental implementation of a QEC code, based upon entanglement among 9 optical beams. In principle, this 9-wavepacket adaptation of Shor's original 9-qubit scheme allows for full quantum error correction against an arbitrary single-beam (single-party) error.Comment: realization of a Gaussian error correction protocol suitable for non-Gaussian error correctio

Composting Characteristics of Bovine Manure Produced by Conventional Stacked Processing and an Experimental Small-Scale Apparatus

Southern Kyushu is an important center of beef production in Japan and the large amounts of bovine waste that are produced in the region need to be utilized in a way that is not harmful to the environment. One such method is to use the manure to produce organic fertilizer, which can then be used to replace the chemical fertilizer that is used for forage production (Hasyim et al., 2014). The composting of bovine manure involves co-digestion of cow manure with substrates such as sawdust and hay. The composting characteristics of these mixtures are influenced by the relative amounts of manure and the substrate used, and by external and internal composting conditions (Guo et al., 2012). Conventional stacked composting requires large volumes of materials, and repeating the composting procedure to produce compost with uniform characteristics is difficult (Kajiya et al., 2013). However, optimization of bovine manure composting has been established using a small-scale apparatus that can be operated by hand (Kajiya et al., 2014). However, the composting characteristics of the apparatus have not yet been compared with those associated with conventional stacked processing. The present study therefore compared the composting characteristics of these two methods in terms of the temperature profile during the composting process, physicochemical properties of composted manure, and percentage germination of plants; all of these methods have been advocated for use as safety indices for compost intended for application to cultivated crops (Cobo et al., 2002)

Impaired coronary capillary hemodynamics with decreased glycocalyx thickness and irregular inner wall remodeling in right ventricle of pulmonary hypertensive rats

We hypothesized that coronary capillary function is impaired with a decreased glycocalyx layer and uneven inner wall remodeling in right ventricles that are hypertrophied due to pulmonary hypertension (PH). Five-week-old male Sprague-Dawley rats were divided into 2 groups (PH: n=25, control: n=27). In the PH group, Monocrotaline (60 mg/kg SC) was administrated at 5 weeks. Coronary capillary hemodynamics was visualized in vivo at 8 weeks of age using our high-resolution intravital videomicrosopy, and RBC velocities in RV capillaries were evaluated, along with capillary diameters. Configuration of the capillary cast was assessed by a confocal laser scanning microscope. The thickness of the glycocalyx on the capillary endothelial surface was evaluated with Alcian blue 8GX by electron microscopy. RV systolic pressure increased in PH (by 142%, p<0.01). The diameters of capillaries were uneven in PH (coefficient of variation of diameters along capillary trees; 24±8% vs. 11±3%, p<0.05). The thickness of the glycocalyx in PH was less than half that of control (0.20±0.05 vs. 0.45±0.14 μm, p<0.05). RBC velocity was decreased in PH (820±110 vs. 1,100±230 μm/sec, p<0.05). The capillary flow reduction in PH may be closely related to the changes in the glycocalyx and vessel irregularity, resulting in insufficient oxygen supply to the heart

A non-linear structure preserving matrix method for the low rank approximation of the Sylvester resultant matrix

A non-linear structure preserving matrix method for the computation of a structured low rank approximation S((f) over bar , (g) over bar) of the Sylvester resultant matrix S(f , g) of two inexact polynomials f = f(y) and g = g(y) is considered in this paper. It is shown that considerably improved results are obtained when f (y) and g(y) are processed prior to the computation of S((f) over bar , (g) over bar), and that these preprocessing operations introduce two parameters. These parameters can either be held constant during the computation of S((f) over bar , (g) over bar), which leads to a linear structure preserving matrix method, or they can be incremented during the computation of S((f) over bar, (g) over bar), which leads to a non-linear structure preserving matrix method. It is shown that the non-linear method yields a better structured low rank approximation of S((f) over bar , (g) over bar) and that the assignment of f (y) and g(y) is important because S((f) over bar , (g) over bar) may be a good structured low rank approximation of S(f, g), but S((f) over bar , (g) over bar) may be a poor structured low rank approximation of S (g f) because its numerical rank is not defined. Examples that illustrate the differences between the linear and non-linear structure preserving matrix methods, and the importance of the assignment off (y) and g(y), are shown. (C) 2010 Elsevier B.V. All rights reserved

Re‐Shaping the Coffee Ring

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/90549/1/2546_ftp.pd

Neues von Kaffeeringen

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/90602/1/2596_ftp.pd