Refine
Year of publication
- 2004 (39) (remove)
Document Type
- Contribution to a Periodical (15)
- Conference Proceeding (12)
- Article (peer reviewed) (4)
- Book (3)
- Part of a Book (3)
- Other (1)
- Working Paper (1)
Has Fulltext
- no (39)
Is part of the Bibliography
- no (39)
Keywords
- FVK (4)
- Holzdecken (3)
- Arbeitsrecht (2)
- DC/DC converter (2)
- EMC (2)
- Finiten Elemente Methode (2)
- Model-Driven Architecture (2)
- Software Development (2)
- Trockenbau (2)
- ARIS (1)
Institute
- Fakultät für Angewandte Gesundheits- und Sozialwissenschaften (8)
- Fakultät für Angewandte Natur- und Geisteswissenschaften (5)
- Fakultät für Holztechnik und Bau (5)
- Fakultät für Informatik (5)
- Fakultät für Ingenieurwissenschaften (5)
- Fakultät für Chemische Technologie und Wirtschaft (3)
- Fakultät für Betriebswirtschaft (1)
The reexposure of a subset of learned material as a retrieval cue can impair recall of the remaining material. Like part-list relearning—the reexposure of learned material for additional learning—this part-list cuing is often assumed to be the result of output order biases at test, caused by the increased strength of the reexposed material. We directly compared the effects of cuing and relearning when controlling for output order biases. In addition, we compared the two forms of reexposure with the effect of part-list retrieval. Both part-list cuing and part-list retrieval reduced recall performance for the remaining material. By contrast, part-list relearning had no such detrimental effect. These results indicate that the effect of reexposure depends on whether material is reexposed as a cue or for relearning, suggesting that part-list cuing reflects an instructional effect. Evidence is provided that part-list cuing leads to instructed covert retrieval of cue items and causes retrieval inhibition of noncue items, similar to how overt retrieval inhibits nonretrieved items.
Process Modelling with ARIS®
(2004)
The strong technical orientation of the previous multimedia evolution shows a lack of theoretical foundation. Both during the evolution and application of multimedia technology, well-founded theoretical concepts are missing. The intention of this paper is to show categories of different information representations and interaction types and their strengths in representing contents. A classification of multimedia information and interaction types is given also as an
overview of the problem fields of multimedia, especially in the field of learning theory. This classification is used to give some guidelines for using and combining multimedia contents in multimedia systems.
Airbag-Markt - Quo vadis?
(2004)
Trockenbau-Atlas: Teil I
(2004)
The simplifications used while creating a model for structure borne transmission from a wood stud to a gypsum board mounted on RCs are discussed.
Above 400 Hz power transmission is determined by stud translation, is propotional to the number of RCs, and is independent of number and location of fasteners between gypsum board and RCs.
In this frequency range it is possible to use the mobility approach if RCs can be approximated by a series of idealised springs located at points of intersection between stud and RCs. The dynamic stiffness of each spring is equal to that of the RC at a stud.
The assumptions relating to power flow as a function of position and number of fasteners between the gypsum board and RC's was examined. It was observed that studs had both a rotational and translation motion but the translation displacement coupled more strongly than rotation. It was also observed that if the rotation velocity was less than or equal to the translation velocity, then structure borne transmission due to the rotation component could be ignored for frequencies below 2500 Hz. The results show that there is little effect associated with either the location or the number of fasteners attaching the gypsum board to the RC's about 315 Hz.
Die vorliegende Arbeit entstand im Rahmen ei
nes Forschungsprojekts des Lehrstuhls für
Computation in Engineering an der Technische
n Universität München in Kooperation mit
dem Fraunhofer Institut für Bauphysik, Stuttg
art und dem ift Schallschutzzentrum, Rosen-
heim. Die primäre Zielsetzung des Forschungsp
rojekts lag in der Entwicklung konstruktiver
Maßnahmen zur Verbesserung der tieffreque
nten Trittschalldämmung von Holzdecken.
Zur Entwicklung dieser Maßnahmen war zunächst durch die Klärung der akustischen
Wechselwirkungen zwischen Deckenauflage
und Rohdecke ein besseres Verständnis für das
Schwingungsverhalten der Dec
kenaufbauten zu erarbeiten
. Um den erheblichen Aufwand
einer rein empirischen (messtechnischen) Untersuchung dieser Wechselwirkungen zu re-
duzieren, wurde die Entwicklung und Bereitste
llung leistungsfähiger Berechnungsmodelle
angestrebt. Im Teilprojekt der Technischen Universität München wurde hierzu ein Be-
rechnungsmodell auf Basis der Finiten Eleme
nte Methode erarbeitet, dessen Validierung
anhand von Messergebnissen aus der Datenbank des ift Schallschutzzentrums, Rosenheim
erfolgte. Zur Visualisierung
der Ergebnisse und einer rationellen Modellerstellung wurde
eine graphische Nutzeroberfläche entwickel
t. Anhand der numerischen Berechnungen des
validierten Modells wurden die Wechselwirkungen der Deckenkomponenten untersucht
und optimierte Konstruktionen erarbeitet. Nach der messtechnischen Überprüfung der
optimierten Konstruktionen im ift Schallschutzzentrum konnten die Ergebnisse in Form von
Konstruktionshilfen für optimierte Au
fbauten zusammengestellt werden.
Die schalltechnische Planung eines Mehrfamilienhauses in Holzbauweise stellt in der Regel
eine größere Herausforderung dar, als die Planung eines vergleichbaren Bauvorhabens in
Beton- und Mauerwerksbauweise.
Die Ursache dieses Ungleichgewichts ist nicht nur in den vielfältigen Gestaltungs- und Ausfüh-
rungsvarianten des Holzbaus zu suchen, sondern vielmehr in den fehlenden Planungsunterla-
gen zum Schallschutz und der ungenügenden Berücksichtigung des Holzbaus in den ein-
schlägigen Normen.
Zur Beseitigung dieser Schieflage wurden in der Vergangenheit unter Koordination der Deut-
schen Gesellschaft für Holzforschung auf Grundlage umfangreicher Forschungsvorhaben ver-
schiedene Schriften in der Reihe Informationsdienst Holz veröffentlicht, die Planungsgrundla-
gen für Decken, Wände und Dächer bilden
[2]
,
[3]
.
Diese Ergebnisse fließen nun auch in die derzeit in Bearbeitung befindliche Neufassung der
DIN 4109 ein. Neben dem Bauteilkatalog wird auch das Nachweisverfahren aktualisiert und
an die europäische Normung (EN 12354) angepasst. Für den Holzbau wurde das Berech-
nungsverfahren inzwischen in verschiedenen Vorhaben verifiziert
[4]
,
[5]
und an die speziellen
Schallübertragungsmechanismen im Holzbau angepasst
[6]
,
[7]
.
Um dem subjektiven Empfinden des Bewohners
gerecht zu werden, ist gerade bei leichten
Holzbauteilen die Berücksichtigung der tieffrequenten Schallübertragung empfehlenswert.
Dies kann in den meisten europäischen Ländern derzeit nur zusätzlich zum schalltechnischen
Nachweis erfolgen, da die normativen Anforderungen die tieffrequente Schallübertragung nur
ungenügend oder gar nicht berücksichtigen.
Nachfolgend wird daher auch auf aktuelle Forschungsergebnisse zur tieffrequenten Übertra-
gung näher eingegangen und die neuen Berechnungsmöglichkeiten für den schalltechnischen
Nachweis im Holzbau vorgestellt. Die Berechnungsergebnisse werden mit Messergebnissen
am Bau verglichen und es werden ergänzende Hinweise zur Vermeidung von Baufehlern ge-
geben.
OBJECTIVES:
To generate a fast and robust 3-D visualization of the operation site during minimal invasive surgery.
METHODS:
Light fields are used to model and visualize the 3-D operation site during minimal invasive surgery. An endoscope positioning robot provides the position and orientation of the endoscope. The a priori un-known transformation from the endoscope plug to the endoscope tip (hand-eye transformation) can either be determined by a three-step algorithm, which includes measuring the endoscope length by hand or by using an automatic hand-eye calibration algorithm. Both methods are described in this paper and their respective computation times and accuracies are compared.
RESULTS:
Light fields were generated during real operations and in the laboratory. The comparison of the two methods to determine the unknown hand-eye transformation was done in the laboratory. The results which are being presented in this paper are: rendered images from the generated light fields, the calculated extrinsic camera parameters and their accuracies with respect to the applied hand-eye calibration method, and computation times.
CONCLUSION:
Using an endoscope positioning robot and knowing the hand-eye transformation, the fast and robust generation of light fields for minimal invasive surgery is possible.
In diesem Beitrag wird zunächst auf die Problematik einer Kostenzuordnung auf Forschung, Lehre und Krankenversorgung in Universitätsklinika näher eingegangen. Im zweiten Abschnitt wird anhand einer aktuellen Untersuchung zur Lage der Hochschulmedizin aufgezeigt, wie derzeit in Deutschland der Landeszuschuss für Forschung und Lehre an die Universitätsklinika und später innerhalb der Klinika an die einzelnen Fachabteilungen verteilt wird. Als eine mögliche Basis für eine Trennungsrechnung schält sich die Arbeitszeitverteilung der ärztlichen Mitarbeiter heraus, die oft anhand von Befragungen ermittelt wird. Deswegen werden im dritten Kapitel die Ergebnisse einer solchen Befragung in einer Abteilung eines Universitätsklinikums dargestellt und die Möglichkeiten sowie Grenzen für eine Kostenzuordnung diskutiert.
For cost–benefit analysis, health technologies with multiple effects should be valued in a single scenario by a holistic willingness‐to‐pay (WTP) measure. Recent studies instead used decomposed scenarios in which respondents report their WTP for each individual effect. Evidence can be found that the sum of such decomposed WTPs overestimates the holistic WTP, i.e. the holistic WTP is sub‐additive. This sum of decomposed WTPs can lead to wrong conclusions on the efficiency of health technologies. This is also relevant in decision making about new technologies that are valued separately in different surveys. To date, no utility‐theoretical and empirically validated aggregation function for decomposed WTPs exists. Within an expected utility model, this paper identifies as a reason for sub‐additivity – beside risk aversion with respect to wealth – a negative influence of better health on the marginal utility of wealth, i.e. marginal utility of wealth is smaller in better health states. Assuming mutual utility independence of health and wealth, a theoretically founded aggregation function covering these two impacts is derived. In a contingent valuation study, 92 patients with diabetes were asked to state their WTP for reductions of the risk of several diabetic complications in decomposed as well as in holistic scenarios. The patients had preferences with a significant negative influence of health on the marginal utility of wealth. Sub‐additivity occurred and theoretically founded aggregation could considerably lower the degree of overestimation. These results suggest that the theoretically founded aggregation function might reduce problems of sub‐additivity that can be economically relevant. Further empirical testing of the approach is indicated.
Introduction
Universal varicella vaccination of infants in Germany was shown to be effective and cost-saving by the EVITA-model (Economic Varicella VaccInation Tool for Analysis).[1] However, affordability proves to be a “fourth hurdle”. The objective of this study is to examine budget impacts of universal varicella vaccination from a payer’s (sickness funds’) perspective.
Methods
The validated, dynamic infections disease model EVITA was used to analyse budget impacts over 30 years. Universal vaccination of children in their second life year was compared to the currently recommended risk-group strategy. In the USA, universal varicella vaccination was implemented in 1996. Based on US-experience, three scenarios for the development of the coverage rates have been estimated. The price level of 2002 was used. Future costs were not discounted to show the full budget impact in future years. Aspects concerning the incidence of herpes zoster have not been included in the analysis.
Results
Under the current risk-group strategy, an annual average of 721,400 cases, 38,700 complications and 5,500 hospitalisations occur in Germany. Annual varicella costs for sickness funds amount to 73 million €, 50 % thereof due to sick-leave costs of parents staying at home to care for their sick child covered by sickness funds. Other costs relate to hospitalisations (24 %), physician services (12 %), medication (11 %) and vaccination (3 %). With a universal vaccination strategy, morbidity is on average reduced by 75 % to 80 % (this and the following results depend on the analysed scenario). Vaccination costs rise to a maximum of 42–43 million € p. a. within about 10–12 years and therefore account — at maximum — for about 0.03 % of the total payers’ health care budget. Other varicella costs however decrease by more than 80 % in the same time. Overall varicella costs rise by 8 % to 13 % in the first few years because of the additional investment in vaccination. In the 6th to 8th year, however, savings in treatment and work loss costs compensate vaccination costs, leading to net savings. Over 30 years, average annual varicella costs decrease by 31 % to 33 % to a level between 49 and 51 million €. Sensitivity analyses showed only marginal variations in these results with maximum coverage rate, price of vaccine, and work loss costs being the most influential variables.
Conclusions
Under the current risk-group vaccination strategy, varicella causes a high burden of disease resulting in considerable utilisation of health care resources and related costs. Universal vaccination can effectively reduce morbidity and utilisation. This strategy has a small impact on overall health care costs. For a short time, investment in varicella vaccination causes additional costs, which are low compared to current annual varicella costs, and does not influence sickness funds’ premiums. Reduced morbidity rapidly leads to savings and significant net-savings occur in 6–8 years.
Objective. The authors performed a methodological comparison of the usual standard gamble with methods that could also be used in mailed questionnaires.Methods.Ninety-two diabetic patients valued diabetes-related health states twice. In face-to-face interviews, the authors used an iterative standard gamble (ISG) in which the probabilities were varied in a ping-pong manner and a self-completion method (SC) with top-down titration as search procedure (SC-TD) in 2 independent subsamples of 46 patients. Three months later, all patients received a mailed questionnaire in which the authors used the self-completion method with bottom-up (SCBU) and SC-TD as search procedures.Results.ISG and SCTD showed feasibility and consistency in the interviews. The ISG resulted in significantly higher utilities than the SC-TD. Two thirds of the mailed questionnaires provided useful results indicating some problems of feasibility. Utilities measured by SC-BU and SC-TD did not differ significantly showing procedural invariance. Further, patients indicated ambivalence when given the choice not to definitely state their preferences.Conclusions.The results show that different strategies to collect standard gamble utilities can yield different results. Compared with the usually applied ISG, the SC method is feasible in interviews and provides a consistent alternative that is less costly when used in mailed questionnaires, although its practicability has to be improved in this later setting.
Java Server Faces
(2004)
Chickenpox infections are generally mild but due to their very high incidence among healthy children they give rise to considerable morbidity and occasional mortality. With the development of a varicella vaccine in the early 1970s and its progressive licensing in many countries, interest in the efficiency of varicella immunisation programmes grew. The objective of this review was to discuss the methodological aspects and results of published economic evaluations of varicella vaccination. From this, we attempted to make recommendations.
A computerised search was carried out; 17 full economic evaluations of varicella vaccination were retrieved. The review identified the methodological divergences and similarities between the articles in four areas: study design, epidemiological data, economic data and model characteristics. We assessed to what extent the applied methods conform to general guidelines for the economic evaluation of healthcare interventions and compared the studies’ results.
The desirability of a universal vaccination programme depends on whose perspective is taken. Despite variability in data and model assumptions, the studies suggest that universal vaccination of infants is attractive to society because large savings occur from averted unproductive days for parents. For the healthcare payer, universal vaccination of infants does not generate savings. Vaccination of susceptible adolescents has been proposed by some authors as a viable alternative; the attractiveness of this is highly dependent on the negative predictive value of anamnestic screening. Targeted vaccination of healthcare workers and immunocompromised individuals appears relatively cost effective. Findings for other target groups are either contradictory or provide insufficient evidence for any unequivocal recommendations to be made. High sensitivity to vaccine price was reported in most studies.
This review highlights that some aspects of these studies need to be further improved before final recommendations can be made. First, more transparency, completeness and compliance to general methodological guidelines are required. Second, because of the increasing severity of varicella with age, it is preferable and in some cases essential to use dynamic models for the assessment of universal vaccination strategies. Third, most studies focused on the strategy of vaccinating children only while their results depended heavily on disputable assumptions (regarding vaccine effectiveness and impact on herpes zoster). Since violation of these assumptions could have important adverse public health effects, we suggest pre-adolescent vaccination as a more secure alternative. This option deserves more attention in future analyses.
Creating long-lived software systems requires a technol ogy to build systems with good maintainability. One of the core ideas of the Model Driven Architecture (MDA) is to ease the change of the run-time platform by raising the level of abstraction in which just the business aspects are modelled, and by separating business aspects from techni cal issues and implementation details. This article anal yses the MDA approach with respect to maintainability. We argue that MDA systems will become even harder to maintain because the maintainability depends on the sys tem's (development) environment. MDA, UML and other base technologies are still under development, therefore the tools will change considerably. While the MDA possibly eases the change of the run-time platform, we show that it is quite difficult to exchange a link in the development tool chain. Our argumentation is based on the general proper ties of software evolution and the dependency chains in the development and run-time environments. It is backed by experiences with MDA development as well as by analo gies to general maintenance experiences.
Dieser Beitrag beschreibt, wie Referenzarchitekturen die MDA nutzbar machen. Die Referenzarchitekturen liefern dabei die konzeptionelle Unterstützung für die Konstruktion und Implementierung von Software und die MDA bietet den Rahmen für eine Werkzeugunterstützung. Die praktische Umsetzbarkeit wird mit dem OpenSource Framework AndroMDA und einer Referenzarchitektur der Firma iteratec GmbH gezeigt.
Exoten mit Potential
(2004)