2,845 research outputs found

    3D Visualization Architecture for Building Applications Leveraging an Existing Validated Toolkit

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    The diagnostic radiology space and healthcare in general is a slow adopter of new software technologies and patterns. Despite the widespread embrace of mobile technology in recent years, altering the manner in which societies in developed countries live and communicate, diagnostic radiology has not unanimously adopted mobile technology for remote diagnostic review. Desktop applications in the diagnostic radiology space commonly leverage a validated toolkit. Such toolkits not only simplify desktop application development but minimize the scope of application validation. For these reasons, such a toolkit is an important piece of a company’s software portfolio. This thesis investigated an approach for leveraging a Java validated toolkit for the purpose of creating numerous ubiquitous applications for 3D diagnostic radiology. Just as in the desktop application space, leveraging such a toolkit minimizes the scope of ubiquitous application validation. Today, the most standard execution environment in an electronic device is an Internet browser; therefore, a ubiquitous application is web application. This thesis examines an approach where ubiquitous applications can be built using a viewport construct provided by a client-side ubiquitous toolkit that hides the client-server communication between the ubiquitous toolkit and the validated visualization toolkit. Supporting this communication is a Java RESTful web service wrapper around the validated visualization toolkit that essentially “webifies” the validated toolkit. Overall, this ubiquitous viewport is easily included in a ubiquitous application and supports remote visualization and manipulation of volumes on the widest range of electronic devices. Overall, this thesis provided a flexible and scalable approach to developing ubiquitous applications that leverage an existing validated toolkit that utilizes industry standard technologies, patterns, and best practices. This approach is significant because it supports easy ubiquitous application development and minimizes the scope of application validation, and allows medical professionals easy anytime and anywhere access to diagnostic images

    Mirror Descent and Convex Optimization Problems With Non-Smooth Inequality Constraints

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    We consider the problem of minimization of a convex function on a simple set with convex non-smooth inequality constraint and describe first-order methods to solve such problems in different situations: smooth or non-smooth objective function; convex or strongly convex objective and constraint; deterministic or randomized information about the objective and constraint. We hope that it is convenient for a reader to have all the methods for different settings in one place. Described methods are based on Mirror Descent algorithm and switching subgradient scheme. One of our focus is to propose, for the listed different settings, a Mirror Descent with adaptive stepsizes and adaptive stopping rule. This means that neither stepsize nor stopping rule require to know the Lipschitz constant of the objective or constraint. We also construct Mirror Descent for problems with objective function, which is not Lipschitz continuous, e.g. is a quadratic function. Besides that, we address the problem of recovering the solution of the dual problem

    Stopping Rules for Gradient Methods for Non-Convex Problems with Additive Noise in Gradient

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    We study the gradient method under the assumption that an additively inexact gradient is available for, generally speaking, non-convex problems. The non-convexity of the objective function, as well as the use of an inexactness specified gradient at iterations, can lead to various problems. For example, the trajectory of the gradient method may be far enough away from the starting point. On the other hand, the unbounded removal of the trajectory of the gradient method in the presence of noise can lead to the removal of the trajectory of the method from the desired exact solution. The results of investigating the behavior of the trajectory of the gradient method are obtained under the assumption of the inexactness of the gradient and the condition of gradient dominance. It is well known that such a condition is valid for many important non-convex problems. Moreover, it leads to good complexity guarantees for the gradient method. A rule of early stopping of the gradient method is proposed. Firstly, it guarantees achieving an acceptable quality of the exit point of the method in terms of the function. Secondly, the stopping rule ensures a fairly moderate distance of this point from the chosen initial position. In addition to the gradient method with a constant step, its variant with adaptive step size is also investigated in detail, which makes it possible to apply the developed technique in the case of an unknown Lipschitz constant for the gradient. Some computational experiments have been carried out which demonstrate effectiveness of the proposed stopping rule for the investigated gradient methods

    On representations of the feasible set in convex optimization

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    We consider the convex optimization problem min{f(x):gj(x)0,j=1,...,m}\min \{f(x) : g_j(x)\leq 0, j=1,...,m\} where ff is convex, the feasible set K is convex and Slater's condition holds, but the functions gjg_j are not necessarily convex. We show that for any representation of K that satisfies a mild nondegeneracy assumption, every minimizer is a Karush-Kuhn-Tucker (KKT) point and conversely every KKT point is a minimizer. That is, the KKT optimality conditions are necessary and sufficient as in convex programming where one assumes that the gjg_j are convex. So in convex optimization, and as far as one is concerned with KKT points, what really matters is the geometry of K and not so much its representation.Comment: to appear in Optimization Letter

    ОСОБЛИВОСТІ БІОХІМІЧНИХ ТА ІМУНОЛОГІЧНИХ МАРКЕРІВ У ДІТЕЙ З КОРОВОЮ ІНФЕКЦІЄЮ ТА В АСОЦІАЦІЇ З ГЛИСТЯНОЮ ІНВАЗІЄЮ

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    SUMMARY. This article presented to the extremely frequency of measles with helminthiasis in the children. We investigated the biochemical and immunological markers of Measles with helminthiasis in the children and complication of the dutarion of disease. Key words: measles, helminthiasis, biochemical investigation, children.Звертається увага на поширені патології дитячого віку – кір та глистяну інвазію. Було вивчено особливості біохімічних та імунологічних маркерів у дітей, хворих на кір та в асоціації з глистяною інвазією, яка ускладнює перебіг основного захворювання – кору. Ключові слова: кір, глистяна інвазія, біохімічне дослідження, діти

    Structural Optimization Using the Newton Modified Barrier Method

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    The Newton Modified Barrier Method (NMBM) is applied to structural optimization problems with large a number of design variables and constraints. This nonlinear mathematical programming algorithm was based on the Modified Barrier Function (MBF) theory and the Newton method for unconstrained optimization. The distinctive feature of the NMBM method is the rate of convergence that is due to the fact that the design remains in the Newton area after each Lagrange multiplier update. This convergence characteristic is illustrated by application to structural problems with a varying number of design variables and constraints. The results are compared with those obtained by optimality criteria (OC) methods and by the ASTROS program

    Synthesis of a PID-controller of a trim robust control system of an autonomous underwater vehicle

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    Autonomous underwater vehicles are often used for performing scientific, emergency or other types of missions under harsh conditions and environments, which can have non-stable, variable parameters. So, the problem of developing autonomous underwater vehicle motion control systems, capable of operating properly in random environments, is highly relevant. The paper is dedicated to the synthesis of a PID-controller of a trim robust control system, capable of keeping an underwater vehicle stable during a translation at different angles of attack. In order to synthesize the PID-controller, two problems were solved: a new method of synthesizing a robust controller was developed and a mathematical model of an underwater vehicle motion process was derived. The newly developed mathematical model structure is simpler than others due to acceptance of some of the system parameters as interval ones. The synthesis method is based on a system poles allocation approach and allows providing the necessary transient process quality in a considered system

    Charge migration engineered by localisation: electron-nuclear dynamics in polyenes and glycine

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    We demonstrate that charge migration can be ‘engineered’ in arbitrary molecular systems if a single localised orbital – that diabatically follows nuclear displacements – is ionised. Specifically, we describe the use of natural bonding orbitals in Complete Active Space Configuration Interaction (CASCI) calculations to form cationic states with localised charge, providing consistently well-defined initial conditions across a zero point energy vibrational ensemble of molecular geometries. In Ehrenfest dynamics simulations following localised ionisation of -electrons in model polyenes (hexatriene and decapentaene) and -electrons in glycine, oscillatory charge migration can be observed for several femtoseconds before dephasing. Including nuclear motion leads to slower dephasing compared to fixed-geometry electron-only dynamics results. For future work, we discuss the possibility of designing laser pulses that would lead to charge migration that is experimentally observable, based on the proposed diabatic orbital approach

    Analysis of trans-resveratrol in oilseeds by high-performance liquid chromatography

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    Oilseeds are very popular edibles that are often used to enhance the fibre content of baked goods, and specific types are used for preserving and seasoning. Polyphenol-related researches have been receiving growing attention in the last 20 years, especially the ones concentrating on stilbenoids. In previous studies, resveratrol concentrations have been determined from oilseeds such as peanut.The aim of our research was to define the composition of oilseeds with a focus on the bioactive compounds, more specifically the resveratrol.Research took place in 2010–2011 at the University of Pécs, Medical School, using non-random, convenience sampling. Oilseeds studied in the research were: sunflower seed, roasted peanut, un-roasted peanut, sesame seed, pumpkin seed, almond, linseed, bio white mustard seed, bio black mustard seed, mustard seed of foreign provenance, and wild black mustard seed. All of these oilseeds can be purchased from trade. Samples used in the research were obtained from the producers and collectors. High Performance Liquid Chromatography (HPLC) was used for the measurements.Summarising our results, it can be stated that each type of oilseed analysed in our research can be regarded as good sources of resveratrol. The highest level of resveratrol was detected in the sunflower seeds (0.00398±0.0001 mg g−1), almonds (0.00176±0.00021 mg g−1), roasted peanut (0.00206±0.00013 mg g−1), and wild black mustard seeds (0.0023±0.0007 mg g−1)
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