Hannover University of Applied Sciences

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Hannover, Germany

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Dunkel J.,Hannover University of Applied Sciences
Proceedings - 2016 4th International Symposium on Computing and Networking, CANDAR 2016 | Year: 2016

The paper presents an innovative architecture for Location-based Recommender Systems integrating different reasoning approaches. Sensor Data Fusion based on Complex Event Processing is applied to achieve location-awareness. Furthermore, it is discussed how traditional recommendations mechanisms such as Content-based Filtering, Collaborative Filtering and Semantic Rules can be extended with user positions to provide location-based recommendations. © 2016 IEEE.


Yazdani S.,Leibniz University of Hanover | Rust W.J.H.,Hannover University of Applied Sciences | Wriggers P.,Leibniz University of Hanover
Composite Structures | Year: 2016

A First-order Shear Deformation Theory (FSDT) is chosen to simulate composite laminates in the linear and the geometrically non-linear regimes. The formulation is based on the Equivalent Single Layer (ESL) theory that fails to predict the delamination onset in composite laminates. The lack of resolving three-dimensional states and correct transverse stresses in this model is principally improved using post-processing. In order to precisely compute interlaminar stresses, a non-frictional linear adhesive contact model is applied in the context of the eXtended Finite Element Method (XFEM). The discontinuities are imposed within any arbitrary interface by enriching the displacement field. Thus two sub-domains define the plane of the discontinuity. Thereafter, the aforementioned adhesive contact can be formulated at the discontinued interface. Stress values are retrieved at nodal points using the interface constitutive equation. Consequently, the interface formulations are extended into the softening regime to model the delamination growth as a mixed-mode cohesive effect. The accuracy of the proposed method in predicting the interlaminar stresses and the delamination propagation is demonstrated by comparing the results with the ones available in literature. By combining the lower-order plate theory and the novel XFEM technique, the model is able to accurately calculate the delamination onset and the propagation with less computational effort. © 2015 Elsevier Ltd.


Dunkel J.,Hannover University of Applied Sciences | Fernandez A.,Rey Juan Carlos University | Ortiz R.,Rey Juan Carlos University | Ossowski S.,Rey Juan Carlos University
Expert Systems with Applications | Year: 2011

Decision support systems for traffic management systems have to cope with a high volume of events continuously generated by sensors. Conventional software architectures do not explicitly target the efficient processing of continuous event streams. Recently, event-driven architectures (EDA) have been proposed as a new paradigm for event-based applications. In this paper we propose a reference architecture for event-driven traffic management systems, which enables the analysis and processing of complex event streams in real-time and is therefore well-suited for decision support in sensor-based traffic control systems. We will illustrate our approach in the domain of road traffic management. In particular, we will report on the redesign of an intelligent transportation management system (ITMS) prototype for the high-capacity road network in Bilbao, Spain. © 2010 Elsevier Ltd. All rights reserved.


Kromker V.,Hannover University of Applied Sciences
Tierärztliche Praxis. Ausgabe G, Grosstiere/Nutztiere | Year: 2015

Mastitis is one of the most common and expensive diseases in dairy cattle. The decision to treat clinical mastitis is usually made without any knowledge of the etiology, and can therefore only be evidence-based to a limited extent. Evidence-based medicine relies essentially on a combination of one's own clinical competence and scientific findings. In mastitis therapy, those insights depend mostly on pathogen-specific factors. Therefore, in evidence-based therapeutic decision making the pathogen identification should serve as a basis for the consideration of scientifically validated therapeutic concepts. The present paper considers evidence-based treatment of clinical mastitis based on a literature review. The authors conclude that an anti-inflammatory treatment using an NSAID should be conducted regardless of the pathogen. However, the choice of an antibiotic therapy depends on the mastitis causative pathogen, clinical symptoms and the animal itself. In principle, a local antibiotic treatment should be chosen for mild and moderate mastitis. It should be noted, that the benefit of an antibiotic therapy for coliform infections is questionable. With knowledge concerning the pathogen, it appears entirely reasonable to refrain from an antibiotic therapy. For severe (i.   e. feverish) mastitis, a parenteral antibiotic therapy should be selected. An extension of the antibiotic therapy beyond the manufacturer's information is only reasonable for streptococcal infections. It is important to make the decision on a prolonged antibiotic therapy only with the knowledge of the mastitis-causative pathogen. In terms of the therapy of a staphylococcus or streptococcus infection, a narrow-spectrum antibiotic from the penicillin family should be adopted when selecting the active agents.


Stockmar A.,Hannover University of Applied Sciences
Light and Engineering | Year: 2011

In general terms, energy efficiency could be regarded as the ratio of the amount or the value of goods produced or services provided to the energy consumed. In the first sense, luminous efficacy is a measure which describes the energy efficiency of a light source (taking into account the additional energy consumed by the control gear if required). In consequence, an energy efficiency measure could be derived as the ratio of the energy consumed during a given time span to the produced/delivered amount of luminous flux, which allows to take into account the variation of the system efficacy over time due to changes of the mode of operation. On the other hand, if lighting is regarded as a service provided, it means the provision of a (required or requested) lighting level (in quantity and quality) in a well defined area (of an interior or an exterior) over a specified time span. In this case the consumed electric energy per time unit, in relation to the reference area and in relation to the lighting level can serve as an energy efficiency measure. Here it is of great importance to consider all relevant influencing factors, such as efficacies and maintenance factors of the light sources, luminous intensity distributions, light output ratios and maintenance factors of the luminaires, installation geometries, modes of operation, and operating times. Due to the large diversity of outdoor areas, tasks, and activities, different energy efficiency measures will be preferable under different circumstances. Examples are given for a number of outdoor lighting applications taking into account the new concepts of adaptive lighting.


Disterer G.,Hannover University of Applied Sciences | Kleiner C.,Hannover University of Applied Sciences
International Journal of Web Portals | Year: 2013

Using mobile devices like smartphones and tablets offers many advantages and has become very popular in private life. Using them in the workplace is also popular, but nobody wants to carry around and handle two devices: one for personal use, and one for work-related tasks. Therefore "Bring Your Own Device" (BYOD) may be appropriate: users make their personal devices available for company use. Apart from improved convenience this also incurs additional opportunities and risks for companies at the same time. We describe and discuss organizational issues, technical approaches, and solutions. Copyright © 2013, IGI Global.


Bruns R.,Hannover University of Applied Sciences | Dunkel J.,Hannover University of Applied Sciences
Software - Practice and Experience | Year: 2014

Recently, event processing (EP) has gained considerable attention as an individual discipline in computer science. From a software engineering perspective, EP systems still lack the maturity of well-established software architectures. For the development of industrial EP systems, generally accepted software architectures based on proven design patterns and principles are still missing. In this article, we introduce a catalog of design patterns that supports the development of event-driven architectures (EDAs) and complex EP systems. The design principles originate from experiences reported in publications as well as from our own experiences in building EP systems with industrial and academic partners. We present several patterns on different layers of abstractions that define the overall structure as well as the building blocks for EP systems. Architectural patterns that determine the top-level structure of an EDA can be distinguished from design patterns that specify the basic mechanisms of EP. The practical application of the catalog of patterns is described by the pattern-based design of a sample EDA for a sensor-based energy control system. Finally, we propose a coherent and general reference architecture for EP derived from the proposed patterns. Copyright © 2013 John Wiley & Sons, Ltd.


Emmert M.,Friedrich - Alexander - University, Erlangen - Nuremberg | Sander U.,Hannover University of Applied Sciences | Pisch F.,Friedrich - Alexander - University, Erlangen - Nuremberg
Journal of Medical Internet Research | Year: 2013

Background: Physician-rating websites are currently gaining in popularity because they increase transparency in the health care system. However, research on the characteristics and content of these portals remains limited. Objective: To identify and synthesize published evidence in peer-reviewed journals regarding frequently discussed issues about physician-rating websites. Methods: Peer-reviewed English and German language literature was searched in seven databases (Medline (via PubMed), the Cochrane Library, Business Source Complete, ABI/Inform Complete, PsycInfo, Scopus, and ISI web of knowledge) without any time constraints. Additionally, reference lists of included studies were screened to assure completeness. The following eight previously defined questions were addressed: 1) What percentage of physicians has been rated? 2) What is the average number of ratings on physician-rating websites? 3) Are there any differences among rated physicians related to socioeconomic status? 4) Are ratings more likely to be positive or negative? 5) What significance do patient narratives have? 6) How should physicians deal with physician-rating websites? 7) What major shortcomings do physician-rating websites have? 8) What recommendations can be made for further improvement of physician-rating websites? Results: Twenty-four articles published in peer-reviewed journals met our inclusion criteria. Most studies were published by US (n=13) and German (n=8) researchers; however, the focus differed considerably. The current usage of physician-rating websites is still low but is increasing. International data show that 1 out of 6 physicians has been rated, and approximately 90% of all ratings on physician-rating websites were positive. Although often a concern, we could not find any evidence of 'doctor-bashing'. Physicians should not ignore these websites, but rather, monitor the information available and use it for internal and ex-ternal purpose. Several shortcomings limit the significance of the results published on physician-rating websites; some recommendations to address these limitations are presented. Conclusions: Although the number of publications is still low, physician-rating websites are gaining more attention in research. But the current condition of physician-rating websites is lacking. This is the case both in the United States and in Germany. Further research is necessary to increase the quality of the websites, especially from the patients' perspective.


Wartena C.,Hannover University of Applied Sciences
CEUR Workshop Proceedings | Year: 2013

Distributional semantics tries to characterize the meaning of words by the contexts in which they occur. Similarity of words hence can be derived from the similarity of contexts. Contexts of a word are usually vectors of words appearing near to that word in a corpus. It was observed in previous research that similarity measures for the context vectors of two words depend on the frequency of these words. In the present paper we investigate this dependency in more detail for one similarity measure, the Jensen-Shannon divergence. We give an empirical model of this dependency and propose the deviation of the observed Jensen-Shannon divergence from the divergence expected on the basis of the frequencies of the words as an alternative similarity measure. We show that this new similarity measure is superior to both the Jensen-Shannon divergence and the cosine similarity in a task, in which pairs of words, taken from Wordnet, have to be classified as being synonyms or not.


Emmert M.,Friedrich - Alexander - University, Erlangen - Nuremberg | Meier F.,Friedrich - Alexander - University, Erlangen - Nuremberg | Pisch F.,Friedrich - Alexander - University, Erlangen - Nuremberg | Sander U.,Hannover University of Applied Sciences
Journal of Medical Internet Research | Year: 2013

Background: Over the past decade, physician-rating websites have been gaining attention in scientific literature and in the media. However, little knowledge is available about the awareness and the impact of using such sites on health care professionals. It also remains unclear what key predictors are associated with the knowledge and the use of physician-rating websites. Objective: To estimate the current level of awareness and use of physician-rating websites in Germany and to determine their impact on physician choice making and the key predictors which are associated with the knowledge and the use of physician-rating websites. Methods: This study was designed as a cross-sectional survey. An online panel was consulted in January 2013. A questionnaire was developed containing 28 questions; a pretest was carried out to assess the comprehension of the questionnaire. Several sociodemographic (eg, age, gender, health insurance status, Internet use) and 2 health-related independent variables (ie, health status and health care utilization) were included. Data were analyzed using descriptive statistics, chi-square tests, and t tests. Binary multivariate logistic regression models were performed for elaborating the characteristics of physician-rating website users. Results from the logistic regression are presented for both the observed and weighted sample. Results: In total, 1505 respondents (mean age 43.73 years, SD 14.39; 857/1505, 57.25% female) completed our survey. Of all respondents, 32.09% (483/1505) heard of physician-rating websites and 25.32% (381/1505) already had used a website when searching for a physician. Furthermore, 11.03% (166/1505) had already posted a rating on a physician-rating website. Approximately 65.35% (249/381) consulted a particular physician based on the ratings shown on the websites; in contrast, 52.23% (199/381) had not consulted a particular physician because of the publicly reported ratings. Significantly higher likelihoods for being aware of the websites could be demonstrated for female participants (P<.001), those who were widowed (P=.01), covered by statutory health insurance (P=.02), and with higher health care utilization (P<.001). Health care utilization was significantly associated with all dependent variables in our multivariate logistic regression models (P<.001). Furthermore, significantly higher scores could be shown for health insurance status in the unweighted and Internet use in the weighted models. Conclusions: Neither health policy makers nor physicians should underestimate the influence of physician-rating websites. They already play an important role in providing information to help patients decide on an appropriate physician. Assuming there will be a rising level of public awareness, the influence of their use will increase well into the future. Future studies should assess the impact of physician-rating websites under experimental conditions and investigate whether physician-rating websites have the potential to reflect the quality of care offered by health care providers.

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