Black-box decomposition approach for computational hemodynamics: One-dimensional models

Increasing efforts exist in integrating different levels of detail in models of the cardiovascular system. For instance, one-dimensional representations are employed to model the systemic circulation. In this context, effective and black-box-type decomposition strategies for one-dimensional networks are needed, so as to: (i) employ domain decomposition strategies for large systemic models (1D-1D coupling) and (ii) provide the conceptual basis for dimensionally-heterogeneous representations (1D-3D coupling, among various possibilities). The strategy proposed in this article works for both of these two scenarios, though the several applications shown to illustrate its performance focus on the 1D-1D coupling case. A one-dimensional network is decomposed in such a way that each coupling point connects two (and not more) of the sub-networks. At each of the M connection points two unknowns are defined: the flow rate and pressure. These 2M unknowns are determined by 2M equations, since each sub-network provides one (non-linear) equation per coupling point. It is shown how to build the 2M x 2M non-linear system with arbitrary and independent choice of boundary conditions for each of the sub-networks. The idea is then to solve this non-linear system until convergence, which guarantees strong coupling of the complete network. In other words, if the non-linear solver converges at each time step, the solution coincides with what would be obtained by monolithically modeling the whole network. The decomposition thus imposes no stability restriction on the choice of the time step size. Effective iterative strategies for the non-linear system that preserve the black-box character of the decomposition are then explored. Several variants of matrix-free Broyden`s and Newton-GMRES algorithms are assessed as numerical solvers by comparing their performance on sub-critical wave propagation problems which range from academic test cases to realistic cardiovascular applications. A specific variant of Broyden`s algorithm is identified and recommended on the basis of its computer cost and reliability. (C) 2010 Elsevier B.V. All rights reserved.

Understanding the "black box" of a health-promotion program : keys to enable health among older persons aging in the context of migration

Although the need to make health services more accessible to persons who have migrated has been identified, knowledge about health-promotion programs (HPPs) from the perspective of older persons born abroad is lacking. This study explores the design experiences and content implemented in an adapted version of a group-based HPP developed in a researcher-community partnership. Fourteen persons aged 70-83 years or older who had migrated to Sweden from Finland or the Balkan Peninsula were included. A grounded theory approach guided the data collection and analysis. The findings showed how participants and personnel jointly helped raise awareness. The participants experienced three key processes that could open doors to awareness: enabling community, providing opportunities to understand and be understood, and confirming human values and abilities. Depending on how the HPP content and design are being shaped by the group, the key processes could both inhibit or encourage opening doors to awareness. Therefore, this study provides key insights into how to enable health by deepening the understanding of how the exchange of health-promoting messages is experienced to be facilitated or hindered. This study adds to the scientific knowledge base of how the design and content of HPP may support and recognize the capabilities of persons aging in the context of migration.

The elusive goal of regional development: between the black box and the political agenda

Includes bibliography

Industrialization in Latin America: from the black box" to the "empty box": a comparison of contemporary industrialization patterns"

Includes bibliography

Die Black Box der Studierenden: Studienmotivation und -verhalten vor und nach der Bologna-Reform

Die Universitäten in Deutschland und der Schweiz haben in den letzten zehn Jahren eine Reihe von Reformen und Veränderungen erlebt. Insbesondere die Bologna-Reform, aber auch die gestiegenen Studierendenzahlen werden dabei mit einer Reihe von nachteiligen Konsequenzen in Verbindung gebracht. In diesem Beitrag untersuchen wir die Frage, inwiefern sich die auf das Studium bezogenen Einstellungen und Verhaltensweisen der Studierenden nach der Bologna-Reform verändert haben. Unsere Datenbasis sind zwei umfangreiche Befragungen, die 2001 und 2012 an der Universität Bern durchgeführt wurden. Die Ergebnisse zeigen, dass sich die soziodemographische Zusammensetzung der Studierenden zwar deutlich verändert hat. Der zeitliche Aufwand für das Studium, die Leistungsmotivation der Studierenden, die Erwerbspartizipation oder der berichtete Zeitdruck haben aber in den letzten zehn Jahren wider Erwarten keine wesentlichen Veränderungen erfahren. Allerdings verfolgen heute mehr Studierende das Ziel, eine gute soziale Position und ein höheres Einkommen zu erreichen. Vor dem Hintergrund dieser Ergebnisse erscheint eine Reform der Reform nicht zwingend erforderlich zu sein.

Looking Inside The Black Box

Intensive family preservation services (IFPS), designed to stabilize at-risk families and avert out-of-home care, have been the focus of many randomized, experimental studies. The emphasis on "gold-standard" evaluation of IFPS has resulted in fewer "black box" studies that describe actual IFPS service patterns and the fidelity with which they adhere to IFPS program theory. Intervention research is important to the advancement of programs designed to protect the safety of children, improve family functioning, as well as prevent out-of-home placement. Employing a retrospective “clinical data-mining” (CDM) methodology, this exploratory study of Families First, an IFPS program, makes use of available information extracted from client records to describe interventions and service patterns provided over a two year period. This study uncovers actual IFPS service patterns, demonstrates IFPS program fidelity, as well as reveals the usefulness of CDM as a social work research methodology. These findings are particularly valuable for program planning and treatment, policy development and evidence-based practice research.