Baekler P.,Dusseldorf University of Applied Sciences |
Hehl F.W.,University of Cologne |
Hehl F.W.,University of Missouri |
Nester J.M.,National Central University
Physical Review D - Particles, Fields, Gravitation and Cosmology | Year: 2011
We propose a cosmological model in the framework of the Poincaré gauge theory of gravity (PG). The gravitational Lagrangian is quadratic in both curvature and torsion. In our specific model, the Lagrangian contains (i) the curvature scalar R and the curvature pseudoscalar X linearly and quadratically (including an RX term) and (ii) pieces quadratic in the torsion vector V and the torsion axial vector A (including a VA term). We show generally that in quadratic PG models we have nearly the same number of parity conserving terms ("world") and of parity violating terms ("shadow world"). This offers new perspectives in cosmology for the coupling of gravity to matter and antimatter. Our specific model generalizes the fairly realistic "torsion cosmologies" of Shie-Nester-Yo (2008) and Chen et al. (2009). With a Friedman type ansatz for an orthonormal coframe and a Lorentz connection, we derive the two field equations of PG in an explicit form and discuss their general structure in detail. In particular, the second field equation can be reduced to first order ordinary differential equations for the curvature pieces R(t) and X(t). Including these along with certain relations obtained from the first field equation and curvature definitions, we present a first order system of equations suitable for numerical evaluation. This is deferred to the second, numerical part of this paper. © 2011 The American Physical Society.
Hanisch C.,Dusseldorf University of Applied Sciences |
Hautmann C.,University of Cologne |
Pluck J.,University of Cologne |
Eichelberger I.,University of Cologne |
Dopfner M.,University of Cologne
Journal of Child Psychology and Psychiatry and Allied Disciplines | Year: 2014
Background: Our indicated Prevention program for preschool children with Externalizing Problem behavior (PEP) demonstrated improved parenting and child problem behavior in a randomized controlled efficacy trial and in a study with an effectiveness design. The aim of the present analysis of data from the randomized controlled trial was to identify the mediating processes that account for these positive treatment effects. We hypothesized that a decrease in negative parenting and increases in positive parenting and parental warmth would mediate the relationship between treatment and child improvement. Method: Parents of 155 children were randomly assigned to the PEP intervention group (n = 91) or a nontreated control group (n = 64). Parents rated their child's problem behavior and their own parenting practices before and after PEP training. Parental warmth was assessed during standardized play situations. Four mediation models were tested using structural equation modeling. Trial registration number ISRCTN12686222; http://www.controlled-trials.com/isrctn/pf/ 12686222. Results: Changes in child externalizing problem behavior were most strongly mediated by reductions of negative parenting in difficult parenting situations. Increases in positive parenting also served as a mediator. Changes in parental warmth, parents' feeling of self-efficacy, and parental mental health did not play a mediating role in the association between PEP treatment and child behavior. Conclusions In our program, the most important component was to teach parents how to reduce dysfunctional parenting strategies in conflict situations. © 2013 The Authors. Journal of Child Psychology and Psychiatry © 2013 Association for Child and Adolescent Mental Health.
Baekler P.,Dusseldorf University of Applied Sciences |
Hehl F.W.,University of Cologne |
Hehl F.W.,University of Missouri
Classical and Quantum Gravity | Year: 2011
Recently, gravitational gauge theories with torsion have been discussed by an increasing number of authors from a classical as well as from a quantum field theoretical point of view. The Einstein-Cartan(-Sciama-Kibble) Lagrangian has been enriched by the parity odd pseudoscalar curvature (Hojman, Mukku and Sayed) and by torsion square and curvature square pieces, likewise of even and odd parity. (i) We show that the inverse of the so-called Barbero-Immirzi parameter multiplying the pseudoscalar curvature, because of the topological Nieh-Yan form, can be appropriately discussed if torsion square pieces are included. (ii) The quadratic gauge Lagrangian with both parities, proposed by Obukhov et al and Baekler et al, emerges also in the framework of Diakonov et al. We establish the exact relations between both approaches by applying the topological Euler and Pontryagin forms in a Riemann-Cartan space expressed for the first time in terms of irreducible pieces of the curvature tensor. (iii) In a Riemann-Cartan spacetime, that is, in a spacetime with torsion, parity-violating terms can be brought into the gravitational Lagrangian in a straightforward and natural way. Accordingly, Riemann-Cartan spacetime is a natural habitat for chiral fermionic matter fields. © 2011 IOP Publishing Ltd.
Kliem S.,TU Braunschweig |
Kroger C.,TU Braunschweig |
Kosfelder J.,Dusseldorf University of Applied Sciences
Journal of Consulting and Clinical Psychology | Year: 2010
Objective: At present, the most frequently investigated psychosocial intervention for borderline personality disorder (BPD) is dialectical behavior therapy (DBT). We conducted a meta-analysis to examine the efficacy and long-term effectiveness of DBT. Method: Systematic bibliographic research was undertaken to find relevant literature from online databases (PubMed, PsycINFO, PsychSpider, Medline). We excluded studies in which patients with diagnoses other than BPD were treated, the treatment did not comprise all components specified in the DBT manual or in the suggestions for inpatient DBT programs, patients failed to be diagnosed according to the Diagnostic and Statistical Manual of Mental Disorders, and the intervention group comprised fewer than 10 patients. Using a mixed-effect hierarchical modeling approach, we calculated global effect sizes and effect sizes for suicidal and self-injurious behaviors. Results: Calculations of postintervention global effect sizes were based on 16 studies. Of these, 8 were randomized controlled trials (RCTs), and 8 were neither randomized nor controlled (nRCT). The dropout rate was 27.3 pre- to posttreatment. A moderate global effect and a moderate effect size for suicidal and self-injurious behaviors were found, when including a moderator for RCTs with borderline-specific treatments. There was no evidence for the influence of other moderators (e.g., quality of studies, setting, duration of intervention). A small impairment was shown from posttreatment to follow-up, including 5 RCTs only. Conclusions: Future research should compare DBT with other active borderline-specific treatments that have also demonstrated their efficacy using several long-term follow-up assessment points. © 2010 American Psychological Association.
Bunder P.,Dusseldorf University of Applied Sciences
Praxis der Kinderpsychologie und Kinderpsychiatrie | Year: 2011
Enhancing Development of Children at Risk and Their Parents by Video Counselling According to the Marte Meo Method Marte Meo is a low-intensity programme of counselling parents and other persons significantly involved with children which aims to foster parenting capacity and facilitate child development. The article describes a preliminary pilot study with the aim of identifying variables for the future evaluation of efficacy and effectiveness of the Marte Meo method. © Vandenhoeck & Ruprecht GmbH & Co. KG.
Chattopadhyay H.,Jadavpur University |
Cemal Benim A.,Dusseldorf University of Applied Sciences
Journal of Heat Transfer | Year: 2011
In the present paper, turbulent heat transfer characteristics of submerged slot jets impinging on a moving surface at a constant temperature up to a Reynolds number of 50,000 have been studied. The turbulent flow field was resolved using the realizable k-ε model due to Shi et al. [1995, "A New k-ε Eddy-Viscosity Model for High Reynolds Number Turbulent Flows-Model Development and Validation", Comput. Fluids, 24, pp. 227-238] after rigorously establishing the adequacy of the model by comparison with large-eddy simulation data. A periodic element from a jet-bank configuration was chosen in the direction of the surface movement. The distribution of heat transfer on impinging surface is found to be significantly affected by the plate motion. However, the mean velocity distribution along vertical direction in the stagnation region is not affected by the plate motion. With increasing surface motion, the initial symmetric distribution changes to an inclined-S type pattern in the direction of the surface movement up to a certain level of surface velocity and the average heat transfer reduces. When the surface motion crosses this level, the net heat transfer starts increasing. The amount of heat transfer was found to be linked with the level of turbulent kinetic energy close to the impingement surface. The surface velocity at which the heat transfer reaches the value corresponding to the fixed surface value increases with increasing Reynolds number. © 2011 American Society of Mechanical Engineers.
Anders D.,University of Siegen |
Weinberg K.,University of Siegen |
Reichardt R.,Dusseldorf University of Applied Sciences
Computational Materials Science | Year: 2012
In modern technical applications diverse multiphase mixtures are used to meet demanding mechanical, chemical and electrical requirements. Consequently multicomponent systems such as biological tissues in medical science, metallic alloys or polymer solutions occupy a crucial role in everyday life. Therefore the material specific modulation of these systems and their application became a subject of recent studies. In this contribution we will study the impact of thermal diffusion (Ludwig-Soret effect) on the microstructural evolution of the binary polymer blend consisting of poly(dimethylsiloxane) and poly(ethyl-methylsiloxane). This polymer blend has a wide range of applications such as coating implementations and cosmetics manufacturing. For this reason we focus on diffusion induced phase separation and coarsening in the presence of a local non-uniform temperature field. In order to capture the microstructural evolution we apply a Cahn-Hilliard phase-field model, which is here extended by an additional thermal diffusivity. The diffusion equation under consideration constitutes a partial differential equation involving spatial derivatives of fourth order. Thus, the variational formulation of the problem requires approximation functions which are piecewise smooth and globally C 1-continuous. In this paper we employ the innovative isogeometric concept of finite element analysis in order to fulfill this demanding continuity requirement. A concluding comparison of experimental observations and numerical simulations of phase separation in the presence of local temperature fields of a critical PDMS/PEMS polymer blend will illustrate the flexibility and versatility of our approach. © 2011 Elsevier B.V. All rights reserved.
Stuhlsatz A.,SMS Siemag AG |
Lippel J.,Dusseldorf University of Applied Sciences |
Zielke T.,Dusseldorf University of Applied Sciences
IEEE Transactions on Neural Networks and Learning Systems | Year: 2012
We present an approach to feature extraction that is a generalization of the classical linear discriminant analysis (LDA) on the basis of deep neural networks (DNNs). As for LDA, discriminative features generated from independent Gaussian class conditionals are assumed. This modeling has the advantages that the intrinsic dimensionality of the feature space is bounded by the number of classes and that the optimal discriminant function is linear. Unfortunately, linear transformations are insufficient to extract optimal discriminative features from arbitrarily distributed raw measurements. The generalized discriminant analysis (GerDA) proposed in this paper uses nonlinear transformations that are learnt by DNNs in a semisupervised fashion. We show that the feature extraction based on our approach displays excellent performance on real-world recognition and detection tasks, such as handwritten digit recognition and face detection. In a series of experiments, we evaluate GerDA features with respect to dimensionality reduction, visualization, classification, and detection. Moreover, we show that GerDA DNNs can preprocess truly high-dimensional input data to low-dimensional representations that facilitate accurate predictions even if simple linear predictors or measures of similarity are used. © 2012 IEEE.
Nonpharmacological treatments: Their influence on quality of life of people with dementia and possible impacts by corresponding instruments: A systematic review of literature [Nichtpharmakologische Therapieansätze: Ihr Einfluss auf die Lebensqualität Demenzkranker und die Rolle der Messinstrumente: Ergebnisse eines Literaturreviews]
Weidekamp-Maicher M.,Dusseldorf University of Applied Sciences
Zeitschrift fur Gerontologie und Geriatrie | Year: 2013
Nonpharmacological treatments can improve the quality of life of people with dementia. The objective of this review is to evaluate the effects of nonpharmacological treatments on quality of life and to analyze corresponding instruments by performing a systematic review of the literature. Candidate studies were first identified by searches of electronic databases. In a second step, additional studies were identified by existing reviews and meta-analysis. A total of 215 studies were collected, of which 51 trials and long-term studies were selected. Most publications were in English. The number of study participants ranged from 6-487, and intervention duration varied from a few hours up to 3.5 years. A positive effect on quality of life was shown in 33 treatments, whereas 12 treatments had no significant effects. Three other interventions had even negative results on quality of life, while 3 further trials showed positive as well as negative effects. © 2012 Springer-Verlag.
Vogel P.,Dusseldorf University of Applied Sciences
IEEE Transactions on Signal Processing | Year: 2012
Examples for LTI systems are found in the literature that cannot be represented as a convolution. Their outputs can be approximated by outputs of FIR filters and considered as generalized convolution systems. These examples illustrate that impulse and frequency response provide no complete description of the system. In this paper, a general theory for discrete-time LTI systems is represented. LTI systems are defined on a signal space, which is a vector space, closed with respect to a shift operation. Signals are not necessarily bounded and need not belong to a normed vector space. Vector space concepts like dependent and independent vectors are transferred to signal spaces in order to define arbitrary LTI systems. A first method, defining LTI systems by independent input signals, shows that impulse and frequency response can be defined independently from each other. According to another method, the signal space is extended by a new input. An equation is given describing all possible outputs belonging to the new input. Extending the signal space to all discrete-time signals reveals universal LTI systems, which are not even generalized convolution systems. © 2012 IEEE.