Motzkin Decomposable Sets

Theodore Motzkin proved, in 1936, that any polyhedral convex set can be expressed as the (Minkowski) sum of a polytope and a polyhedral convex cone. We have provided several characterizations of the larger class of closed convex sets, Motzkin decomposable, in finite dimensional Euclidean spaces which are the sum of a compact convex set with a closed convex cone. These characterizations involve different types of representations of closed convex sets as the support functions, dual cones and linear systems whose relationships are also analyzed. The obtaining of information about a given closed convex set F and the parametric linear optimization problem with feasible set F from each of its different representations, including the Motzkin decomposition, is also discussed. Another result establishes that a closed convex set is Motzkin decomposable if and only if the set of extreme points of its intersection with the linear subspace orthogonal to its lineality is bounded. We characterize the class of the extended functions whose epigraphs are Motzkin decomposable sets showing, in particular, that these functions attain their global minima when they are bounded from below. Calculus of Motzkin decomposable sets and functions is provided.

Some Fixed Point Theorems for Kannan Mappings

2000 Mathematics Subject Classification: Primary: 47H10; Secondary: 54H25.

Kontinuierliche Karrieren - diskontinuierliches Denken? Entwicklungslinien der pädagogischen Wissenschaftsgeschichte am Beispiel der Berufs- und Wirtschaftspädagogik nach 1954

Die Frage des Neubeginns pädagogischer Wissenschaft in Deutschland wird hier im Blick auf die gesellschaftliche Funktion von Wissenschaft gestellt und am Beispiel einer Teildisziplin, der Berufs- und Wirtschaftspädagogik (BWP), vorläufig beantwortet. Basis dafür sind die Berufsbiographien sowie die Theorie- und Wissensproduktion samt der Diskursform von 23 Hochschullehrern der BWP, dem vermutlich vollständigen Personenkorpus dieser Disziplin und der ersten Generation ihrer Vertreter in Westdeutschland nach 1945. Danach zeichnet sich die BWP durch personale Kontinuität, theoretische Homogenität und diskursive Selbstreferentialität aus und zeigt sich dieser Konstanz nach als ein geschlossener Wissenschaftsprozeß seit 1930 bis 1960. Der war freilich politisch offen; gesellschaftlich gesehen war und verhielt sich die Disziplin funktional. (DIPF/Orig.)

Valve friction and nonlinear process model closed-loop identification

Among several process variability sources, valve friction and inadequate controller tuning are supposed to be two of the most prevalent. Friction quantification methods can be applied to the development of model-based compensators or to diagnose valves that need repair, whereas accurate process models can be used in controller retuning. This paper extends existing methods that jointly estimate the friction and process parameters, so that a nonlinear structure is adopted to represent the process model. The developed estimation algorithm is tested with three different data sources: a simulated first order plus dead time process, a hybrid setup (composed of a real valve and a simulated pH neutralization process) and from three industrial datasets corresponding to real control loops. The results demonstrate that the friction is accurately quantified, as well as ""good"" process models are estimated in several situations. Furthermore, when a nonlinear process model is considered, the proposed extension presents significant advantages: (i) greater accuracy for friction quantification and (ii) reasonable estimates of the nonlinear steady-state characteristics of the process. (C) 2010 Elsevier Ltd. All rights reserved.

A simple closed-loop membrane process for the purification of active pharmaceutical ingredients

Dissertação para obtenção do Grau de Mestre em Engenharia Química e Bioquímica

A forgotten little chapter on isoperimetric inequalities. On the fraction of a convex and closed plane area lying outside a circle with which it shares a diameter

[EN]Often some interesting or simply curious points are left out when developing a theory. It seems that one of them is the existence of an upper bound for the fraction of area of a convex and closed plane area lying outside a circle with which it shares a diameter, a problem stemming from the theory of isoperimetric inequalities. In this paper such a bound is constructed and shown to be attained for a particular area. It is also shown that convexity is a necessary condition in order to avoid the whole area lying outside the circle

Study of the performance of aids to navigation systems : phase 1, closed loop model of the process of navigation /

Final report; March 1978.

An algorithm for computerized automatic tuning of power system stabilizers

The main objective of this paper is to relieve the power system engineers from the burden of the complex and time-consuming process of power system stabilizer (PSS) tuning. To achieve this goal, the paper proposes an automatic process for computerized tuning of PSSs, which is based on an iterative process that uses a linear matrix inequality (LMI) solver to find the PSS parameters. It is shown in the paper that PSS tuning can be written as a search problem over a non-convex feasible set. The proposed algorithm solves this feasibility problem using an iterative LMI approach and a suitable initial condition, corresponding to a PSS designed for nominal operating conditions only (which is a quite simple task, since the required phase compensation is uniquely defined). Some knowledge about the PSS tuning is also incorporated in the algorithm through the specification of bounds defining the allowable PSS parameters. The application of the proposed algorithm to a benchmark test system and the nonlinear simulation of the resulting closed-loop models demonstrate the efficiency of this algorithm. (C) 2009 Elsevier Ltd. All rights reserved.

On the Filtering Problem for Continuous-Time Markov Jump Linear Systems with no Observation of the Markov Chain

We consider in this paper the optimal stationary dynamic linear filtering problem for continuous-time linear systems subject to Markovian jumps in the parameters (LSMJP) and additive noise (Wiener process). It is assumed that only an output of the system is available and therefore the values of the jump parameter are not accessible. It is a well known fact that in this setting the optimal nonlinear filter is infinite dimensional, which makes the linear filtering a natural numerically, treatable choice. The goal is to design a dynamic linear filter such that the closed loop system is mean square stable and minimizes the stationary expected value of the mean square estimation error. It is shown that an explicit analytical solution to this optimal filtering problem is obtained from the stationary solution associated to a certain Riccati equation. It is also shown that the problem can be formulated using a linear matrix inequalities (LMI) approach, which can be extended to consider convex polytopic uncertainties on the parameters of the possible modes of operation of the system and on the transition rate matrix of the Markov process. As far as the authors are aware of this is the first time that this stationary filtering problem (exact and robust versions) for LSMJP with no knowledge of the Markov jump parameters is considered in the literature. Finally, we illustrate the results with an example.

Closed-loop model re-identification of processes under MPC with zone control

This work deals with a procedure for model re-identification of a process in closed loop with ail already existing commercial MPC. The controller considered here has a two-layer structure where the upper layer performs a target calculation based on a simplified steady-state optimization of the process. Here, it is proposed a methodology where a test signal is introduced in a tuning parameter of the target calculation layer. When the outputs are controlled by zones instead of at fixed set points, the approach allows the continuous operation of the process without an excessive disruption of the operating objectives as process constraints and product specifications remain satisfied during the identification test. The application of the method is illustrated through the simulation of two processes of the oil refining industry. (c) 2008 Elsevier Ltd. All rights reserved.

Bridging the gap between closed and open data. System proposal for the Portuguese Legislation

Esta dissertação apresenta uma proposta de sistema capaz de preencher a lacuna entre documentos legislativos em formato PDF e documentos legislativos em formato aberto. O objetivo principal é mapear o conhecimento presente nesses documentos de maneira a representar essa coleção como informação interligada. O sistema é composto por vários componentes responsáveis pela execução de três fases propostas: extração de dados, organização de conhecimento, acesso à informação. A primeira fase propõe uma abordagem à extração de estrutura, texto e entidades de documentos PDF de maneira a obter a informação desejada, de acordo com a parametrização do utilizador. Esta abordagem usa dois métodos de extração diferentes, de acordo com as duas fases de processamento de documentos – análise de documento e compreensão de documento. O critério utilizado para agrupar objetos de texto é a fonte usada nos objetos de texto de acordo com a sua definição no código de fonte (Content Stream) do PDF. A abordagem está dividida em três partes: análise de documento, compreensão de documento e conjunção. A primeira parte da abordagem trata da extração de segmentos de texto, adotando uma abordagem geométrica. O resultado é uma lista de linhas do texto do documento; a segunda parte trata de agrupar os objetos de texto de acordo com o critério estipulado, produzindo um documento XML com o resultado dessa extração; a terceira e última fase junta os resultados das duas fases anteriores e aplica regras estruturais e lógicas no sentido de obter o documento XML final. A segunda fase propõe uma ontologia no domínio legal capaz de organizar a informação extraída pelo processo de extração da primeira fase. Também é responsável pelo processo de indexação do texto dos documentos. A ontologia proposta apresenta três características: pequena, interoperável e partilhável. A primeira característica está relacionada com o facto da ontologia não estar focada na descrição pormenorizada dos conceitos presentes, propondo uma descrição mais abstrata das entidades presentes; a segunda característica é incorporada devido à necessidade de interoperabilidade com outras ontologias do domínio legal, mas também com as ontologias padrão que são utilizadas geralmente; a terceira característica é definida no sentido de permitir que o conhecimento traduzido, segundo a ontologia proposta, seja independente de vários fatores, tais como o país, a língua ou a jurisdição. A terceira fase corresponde a uma resposta à questão do acesso e reutilização do conhecimento por utilizadores externos ao sistema através do desenvolvimento dum Web Service. Este componente permite o acesso à informação através da disponibilização de um grupo de recursos disponíveis a atores externos que desejem aceder à informação. O Web Service desenvolvido utiliza a arquitetura REST. Uma aplicação móvel Android também foi desenvolvida de maneira a providenciar visualizações dos pedidos de informação. O resultado final é então o desenvolvimento de um sistema capaz de transformar coleções de documentos em formato PDF para coleções em formato aberto de maneira a permitir o acesso e reutilização por outros utilizadores. Este sistema responde diretamente às questões da comunidade de dados abertos e de Governos, que possuem muitas coleções deste tipo, para as quais não existe a capacidade de raciocinar sobre a informação contida, e transformá-la em dados que os cidadãos e os profissionais possam visualizar e utilizar.

Closed hybrid hierarchical reservoirs based on the deconstruction of the cellular native microenvironment

The stem cell niche organization and dynamics provide valuable cues for the development of mimetic environments that could have potential to stimulate the regenerative process. We propose the use of biodegradable biomaterials to produce closed miniaturised structures able to encapsulate different cell types or bioactive molecules. In particular, capsules are fabricated using the so-called layer-by-layer technology, where the consecutive (nano-sized) layers are well stabilized by electrostatic interactions or other weak forces. Using alginate-based spherical templates containing cells or other elements (e.g. proteins, magnetic nanoparticles, microparticles) it is possible to produce liquefied capsules that may entrap the entire cargo under mild conditions. The inclusion of liquefied micropcapsules may be used to produce hierarchical compartmentalised systems for the delivery of bioactive agents. The presence of solid microparticles inside such capsules offers adequate surface area for adherent cell attachment increasing the biological performance of these hierarchical systems, while maintain both permeability and injectability. We demonstrated that the encapsulation of distinct cell types (including mesenchymal stem cells and endothelial cells) enhances the osteogenic capability of this system, that could be useful in bone tissue engineering applications.

Wet Oxidation of TMP Concentrated Paper Mill Process Water. Kinetics of the reaction

Työn tarkoituksena oli tutkia lämpötilan, paineen, pH:n ja katalyytin vaikutusta paperitehtaan TMP-konsentroidun prosessiveden märkähapetuksessa. Teoriaosio sisältää katsauksen sellu- ja paperiteollisuuteen, jätevesien käsittelyyn, nanosuodatuksen ja märkähapetusprosessin toimintaperiaatteet ja sovellukset hybriditeknologialle nanosuodatus-märkähapetuksessa. Empiirinen osa koostuu märkähapetuskokeista eri lämpötiloissa, paineissa, pH:ssa ja eri katalyyseillä. Työssä tutkittiin näiden vaikutusta kemialliseen hapenkulutukseen (COD), Biologiseen hapenkulutukseen (BOD), Välittömästi saatavana olevan biologisen hapenkulutukseen (IABOD), ligniiniin, täysin orgaanisen hiileen (TOC) ja rasvaliukoisten uuteaineiden (LWEs) pitoisuuteen. Tuloksina kokeellisesta työstä saatiin korkeimmat COD:n alenemat ja BOD/COD (biohajoavuus) suurimmilla lämpötilaolosuhteilla (COD:n alenema 70 % ja BOD/COD 97 % 200 °C:ssa ja hapen 10 bar osapaineella). Tutkimuksessa, jossa selvitettiin hapen osapaineen vaikutusta saatiin tuloksena, että hapen osapaineen kasvu parantaa orgaanisen kuormituksen poistoa: COD poisto oli olosuhteilla130°C, 5bar 5 %, olosuhteilla 130 °C, 15bar 15 %, olosuhteilla 170 °C, 5bar 20 % ja olosuhteilla 170 °C, 15bar 50 %. Lähes täydellinen LWEs –poisto saavutettiin 150 °C ja 10bar olosuhteilla, vaikka tässä lämpötilassa ei saavutettu korkeata orgaanisen kuormituksen poistoa. Emäksinen pH vaikutti suosivan hapettavia reaktioita, koska korkein COD:n poisto saavutettiin näissä olosuhteilla; kuitenkin alkalisen väliaineen tehokkuudelle löydettiin tärkeä lämpötilariippuvuus.

Simultaneous determination of Cd and Pb in antibiotics used in sugar-cane fermentation process by GFAAS

A method has been developed for the simultaneous determination of Cd and Pb in antibiotics used in sugar-cane fermentation by GFAAS. The integrated platform of transversely heated graphite atomizer was treated with tungsten to form a coating of tungsten carbide. Six samples of commercial solid antibiotics were analyzed by injecting 20 µL of digested samples into the pretreated graphite platform with co-injection of 5 µL of 1000 mg L-1 Pd as chemical modifier. Samples were mineralized in a closed-vessel microwave-assisted acid-digestion system using nitric acid plus hydrogen peroxide. The pyrolysis and atomization temperatures of the heating program of the atomizer were selected as 600°C and 2200°C, respectively. The calculated characteristic mass for Cd and Pb was 1.6 pg and 42 pg, respectively. Limits of detection (LOD) based on integrated absorbance were 0.02 µg L-1 Cd and 0.7 µg L-1 Pb and the relative standard deviations (n = 10) for Cd and Pb were 5.7% and 8.0%, respectively. The recoveries of Cd and Pb added to the digested samples varied from 91% to 125% (Cd) and 80% to 112% (Pb).

The social dimension: a neglected policy item in the Bologna Process

Since its beginning in 1999, the Bologna Process has influenced various aspects of higher education in its member countries, e.g., degree structures, mobility, lifelong learning, social dimension and quality assurance. The social dimension creates the focus of this research. The social dimension entered the Bologna Process agenda in 2001. Despite a decade of reforms, it somehow remained as a vague element and received low scholarly attention. This research addresses to this gap. Firstly, different meanings of the social dimension according to the major European policy actors are analysed. Unfolding the understandings of the actors revealed that the social dimension is mostly understood in terms reflecting the diversity of population on the student body accessing to, progressing in and completing higher education, with a special concern on the underrepresented groups. However, it is not possible to observe a similar commonality concerning the actual policy measures to achieve this goal. Divergence occurs with respect to the addressed underrepresented groups, i.e., all underrepresented groups or people without formal qualifications and mature learners, and the values and institutional interests traditionally promoted by these actors. Secondly, the dissertation discusses the reflection of this social dimension understanding at the national level by looking at cases of Finland, Germany and Turkey. The in-depth analyses show an awareness of the social dimension among most of the national Bologna Process actors and a common understanding of the social dimension goals. However, this understanding has not triggered action in any of the countries. The countries acted on areas which they defined problematic before the Bologna Process. Finally, based on these findings the dissertation discusses the social dimension as a policy item that managed to get into the Bologna Process agenda, but neither grew into an implementable policy, nor drop out of it. To this aim, it makes use of the multiple streams framework and explains the low agenda status social dimension with: i. the lack of a pressing problem definition: the lack of clearly defined indicators and a comprehensive monitoring system, ii. the lack of a viable solution alternative: the proposal of developing national strategies and action plans closed the way to develop generic guidelines for the social dimension to be translated into national policy processes, iii. low political perceptivity: the recent trends opt for increasing efficiency, excellence and exclusiveness discourses rather than ensuring equality and inclusiveness iv. high constraints: the social dimension by definition requires more public funding which is less appreciated and strategic constraints of the actors in allocating their resources v. the type of policy entrepreneur: the social dimension is promoted by an international stakeholder, the European Students’ Union, instead of the ministers responsible for higher education The social dimension remains a policy item in the Bologna Process which is noble enough to agree but not urgent enough to act on.