Role-based Adaptation of Business Reference Models to Application Models: An Enterprise Modeling Methodology for Software Construction

Large software systems are in need of a construction plan to determine and define every concept and element used in order to not end up in complex, unusable, and cost-intensive systems. Different modeling languages, like UML, support the development of these construction plans and visualize them for the system’s stakeholders. Reference models are a specific kind of construction plan, used as templates for information systems and already capture business domain knowledge for reuse and tailoring. By adaptation, reference models are tailored to enterprise-specific application models, which can be used for software construction and maintenance. However, current adaptation methods suffer from the limitations of pure object-oriented development (e.g., identity issues, large inheritance trees, and inflexibility). In this thesis, the usage of roles as the sole adaptation mechanism is proposed to solve these challenges. With the help of conceptual roles, it is possible to create rich model variations and adaptations from existing (industry standard) reference models, and it is simpler to react to model evolution and changing business logic. Adaptations can be specified with more precision by maintaining or even increasing the model’s expressiveness. As a consequence, the role-enriched final application model can be used to describe software systems in more detail, with different perspectives, and, if available, can be implemented with a role supporting programming language. However, even without this step, the application model itself will provide valuable insights into the overall construction plan of a software system by the combination of structure and behavior and a clear separation of relatively stable domain knowledge from its use case specific adaptation

Einfluss von Softwarearchitektur auf den Wert eines Softwaresystems

Softwaresysteme sind ein wichtiger Bestandteil in der heutigen digitalen Welt und müssen oft als fundamentales Investitionsgut von Unternehmen betrachtet werden. Deswegen benötigen solche Systeme eine betriebswirtschaftliche Sichtweise: der Wert als operatives System sowie als langfristige finanzielle Investition bezüglich zukünftiger Anforderungen. Die Grundlage jeden guten Softwaresystems liegt in dessen Architektur, dem Zusammenhang von allen Teilen und deren Beziehungen untereinander, dem inneren Aufbau und der Organisation der Teile. Der Zusammenhang zwischen guter Architektur und resultierender guter Evolutionsfähigkeit und Zukunftsfähigkeit eines Systems ist generell in den Meinungen vertreten. Jedoch liegen dazu nur wenige Literaturstellen vor, welche die Thematik tatsächlich mehr als nur empirisch aufzeigen. Diese Arbeit soll einen möglichen Weg aufzeigen, wie mithilfe eines modellbasierten Ansatzes ein kausaler und quantitiver Zusammenhang zwischen Architektur eines Softwaresystems und dem resultierenden betriebswirtschaftlichen Wert (im Sinne der Evolutionsfähigkeit) hergestellt werden kann

A Query, a Minute: Evaluating Performance Isolation in Cloud Databases

Several cloud providers offer reltional databases as part of their portfolio. It is however not obvious how resource virtualization and sharing, which is inherent to cloud computing, influence performance and predictability of these cloud databases. Cloud providers give little to no guarantees for consistent execution or isolation from other users. To evaluate the performance isolation capabilities of two commercial cloud databases, we ran a series of experiments over the course of a week (a query, a minute) and report variations in query response times. As a baseline, we ran the same experiments on a dedicated server in our data center. The results show that in the cloud single outliers are up to 31 times slower than the average. Additionally, one can see a point in time after which the average performance of all executed queries improves by 38 %

Role-based Runtime Model Synchronization

Model-driven Software Development (MDSD) promotes the use of multiple related models to realize a software system systematically. These models usually contain redundant information but are independently edited. This easily leads to inconsistencies among them. To ensure consistency among multiple models, model synchronizations have to be employed, e.g., by means of model transformations, trace links, or triple graph grammars. Model synchronization poses three main problems for MDSD. First, classical model synchronization approaches have to be manually triggered to perform the synchronization. However, to support the consistent evolution of multiple models, it is necessary to immediately and continuously update all of them. Second, synchronization rules are specified at design time and, in classic approaches, cannot be extended at runtime, which is necessary if metamodels evolve at runtime. Finally, most classical synchronization approaches focus on bilateral model synchronization, i.e., the synchronization between two models. Consequently, for more than two models, they require the definition of pairwise model synchronizations leading to a combinatorial explosion of synchronization rules. To remedy these issues, we propose a role-based approach for runtime model synchronization. In particular, we propose role-based synchronization rules that enable the immediate and continuous propagation of changes to multiple interrelated models (and back again). Additionally, our approach permits adding new and customized synchronization rules at runtime. We illustrate the benefits of role-based runtime model synchronization using the Families to Persons case study from the Transformation Tool Contest 2017

Multimorbidity and long-term care dependency - a five-year follow-up.

BACKGROUND: Not only single, but also multiple, chronic conditions are becoming the normal situation rather than the exception in the older generation. While many studies show a correlation between multimorbidity and various health outcomes, the long-term effect on care dependency remains unclear. The objective of this study is to follow up a cohort of older adults for 5 years to estimate the impact of multimorbidity on long-term care dependency. METHODS: This study is based on claims data from a German health insurance company. We included 115,203 people (mean age: 71.5 years, 41.4% females). To identify chronic diseases and multimorbidity, we used a defined list of 46 chronic conditions based on ICD-10 codes. Multimorbidity was defined as three or more chronic conditions from this list. The main outcome was "time until long-term care dependency". The follow-up started on January 1st, 2005 and lasted for 5 years until December 31st, 2009. To evaluate differences between those with multimorbidity and those without, we calculated Kaplan-Meier curves and then modeled four distinct Cox proportional hazard regressions including multimorbidity, age and sex, the single chronic conditions, and disease clusters. RESULTS: Mean follow-up was 4.5 years. People with multimorbidity had a higher risk of becoming care dependent (HR: 1.85, CI 1.78-1.92). The conditions with the highest risks for long-term care dependency are Parkinson's disease (HR: 6.40 vs. 2.68) and dementia (HR: 5.70 vs. 2.27). Patients with the multimorbidity pattern "Neuropsychiatric disorders" have a 79% higher risk of care dependency. CONCLUSIONS: The results should form the basis for future health policy decisions on the treatment of patients with multiple chronic diseases and also show the need to introduce new ways of providing long-term care to this population. A health policy focus on chronic care management as well as the development of guidelines for multimorbidity is crucial to secure health services delivery for the older population

Overutilization of ambulatory medical care in the elderly German population? – An empirical study based on national insurance claims data and a review of foreign studies

Background: By definition, high utilizers receive a large proportion of medical services and produce relatively high costs. The authors report the results of a study on the utilization of ambulatory medical care by the elderly population in Germany in comparison to other OECD countries. Evidence points to an excessive utilization in Germany. It is important to document these utilization figures and compare them to those in other countries since the healtcare system in Germany stopped recording ambulatory healthcare utilization figures in 2008. Methods: The study is based on the claims data of all insurants aged >= 65 of a statutory health insurance company in Germany (n = 123,224). Utilization was analyzed by the number of contacts with physicians in ambulatory medical care and by the number of different practices contacted over one year. Criteria for frequent attendance were = 50 contacts with practices or contacts with = 10 different practices or = 3 practices of the same discipline per year. Descriptive statistical analysis and logistic regression were applied. Morbidity was analyzed by prevalence and relative risk for frequent attendance for 46 chronic diseases. Results: Nineteen percent of the elderly were identified as high utilizers, corresponding to approximately 3.5 million elderly people in Germany. Two main types were identified. One type has many contacts with practices, belongs to the oldest age group, suffers from severe somatic diseases and multimorbidity, and/or is dependent on long-term care. The other type contacts large numbers of practices, consists of younger elderly who often suffer from psychiatric and/or psychosomatic complaints, and is less frequently multimorbid and/or nursing care dependent. Conclusion: We found a very high rate of frequent attendance among the German elderly, which is unique among the OECD countries. Further research should clarify its reasons and if this degree of utilization is beneficial for elderly people

Patterns of ambulatory medical care utilization in elderly patients with special reference to chronic diseases and multimorbidity - Results from a claims data based observational study in Germany

<p>Abstract</p> <p>Background</p> <p>In order to estimate the future demands for health services, the analysis of current utilization patterns of the elderly is crucial. The aim of this study is to analyze ambulatory medical care utilization by elderly patients in relation to age, gender, number of chronic conditions, patterns of multimorbidity, and nursing dependency in Germany.</p> <p>Methods</p> <p>Claims data of the year 2004 from 123,224 patients aged 65 years and over which are members of one nationwide operating statutory insurance company in Germany were studied. Multimorbidity was defined as the presence of 3 or more chronic conditions of a list of 46 most prevalent chronic conditions based on ICD 10 diagnoses. Utilization was analyzed by the number of contacts with practices of physicians working in the ambulatory medical care sector and by the number of different physicians contacted for every single chronic condition and their most frequent triadic combinations. Main statistical analyses were multidimensional frequency counts with standard deviations and confidence intervals, and multivariable linear regression analyses.</p> <p>Results</p> <p>Multimorbid patients had more than twice as many contacts per year with physicians than those without multimorbidity (36 vs. 16). These contact frequencies were associated with visits to 5.7 different physicians per year in case of multimorbidity vs. 3.5 when multimorbidity was not present. The number of contacts and of physicians contacted increased steadily with the number of chronic conditions. The number of contacts varied between 35 and 54 per year and the number of contacted physicians varied between 5 to 7, depending on the presence of individual chronic diseases and/or their triadic combinations. The influence of gender or age on utilization was small and clinically almost irrelevant. The most important factor influencing physician contact was the presence of nursing dependency due to disability.</p> <p>Conclusion</p> <p>In absolute terms, we found a very high rate of utilization of ambulatory medical care by the elderly in Germany, when multimorbidity and especially nursing dependency were present. The extent of utilization by the elderly was related both to the number of chronic conditions and to the individual multimorbidity patterns, but not to gender and almost not to age.</p

Ambulatory health services utilization in patients with dementia - Is there an urban-rural difference?

<p>Abstract</p> <p>Background</p> <p>Due to demographic changes and an un-equal distribution of physicians, regional analyses of service utilization of elderly patients are crucial, especially for diseases with an impact like dementia. This paper focuses on dementia patients. The aim of the study is to identify differences in service utilization of incident dementia patients in urban and rural areas.</p> <p>Methods</p> <p>Basis for the analysis were all insured persons of a German Health Insurance fund (the GEK) aged 65 years and older living in rural and urban areas. We focussed on physician contacts in the outpatient sector during the first year after an incidence diagnosis of dementia. Special attention was given to contacts with primary care physicians and neurologists/psychiatrists. The dementia cohort was analyzed together with a non-dementia control group drawn according to age, gender and amount of physician contacts. Uni- and bivariate as well as multivariate analysis were performed to estimate the influences on service utilization.</p> <p>Results</p> <p>Results show that the provision of primary care seems to be equally given in urban and rural areas. For specialists contacts however, rural patients are less likely to consult neurologists or psychiatrists. This trend can already be seen before the incident diagnosis of dementia. All consultations rise in the quarter of the incident dementia diagnosis compared to the control group. The results were also tested in a linear and a logistic regression, showing a higher chance for persons living in urban areas to visit a specialist and an overall higher rate in service utilization for dementia patients.</p> <p>Conclusions</p> <p>Because of a probable increase in the number of dementia patients, service provision has to be accessible even in rural areas. Due to this and the fact that demographic change is happening at different paces in different regions, regional variations have to be considered to ensure the future service provision.</p

Comparison of different methods for post-therapeutic dosimetry in [177Lu]Lu-PSMA-617 radioligand therapy

Background Dosimetry is of high importance for optimization of patient-individual PSMA-targeted radioligand therapy (PSMA-RLT). The aim of our study was to evaluate and compare the feasibility of different approaches of image-based absorbed dose estimation in terms of accuracy and effort in clinical routine. Methods Whole-body planar images and SPECT/CT images were acquired from 24 patients and 65 cycles at 24h, 48h, and ≥96h after administration of a mean activity of 6.4 GBq [177Lu]Lu-PSMA-617 (range 3–10.9 GBq). Dosimetry was performed by use of the following approaches: 2D planar-based dosimetry, 3D SPECT/CT-based dosimetry, and hybrid dosimetry combining 2D and 3D data. Absorbed doses were calculated according to IDAC 2.1 for the kidneys, the liver, the salivary glands, and bone metastases. Results Mean absorbed doses estimated by 3D dosimetry (the reference method) were 0.54 ± 0.28 Gy/GBq for the kidneys, 0.10 ± 0.05 Gy/GBq for the liver, 0.81 ± 0.34 Gy/GBq for the parotid gland, 0.72 ± 0.39 Gy/GBq for the submandibular gland, and 1.68 ± 1.32 Gy/GBq for bone metastases. Absorbed doses of normal organs estimated by hybrid dosimetry showed small, non-significant differences (median up to 4.0%) to the results of 3D dosimetry. Using 2D dosimetry, in contrast, significant differences (median up to 10.9%) were observed. Regarding bone metastases, small, but significant differences (median up to 7.0%) of absorbed dose were found for both, 2D dosimetry and hybrid dosimetry. Bland-Altman analysis revealed high agreement between hybrid dosimetry and 3D dosimetry for normal organs and bone metastases, but substantial differences between 2D dosimetry and 3D dosimetry. Conclusion Hybrid dosimetry provides high accuracy in estimation of absorbed dose in comparison to 3D dosimetry for all important organs and is therefore feasible for use in individualized PSMA-RLT

Integrin αE(CD103) Is Involved in Regulatory T-Cell Function in Allergic Contact Hypersensitivity

Murine contact hypersensitivity (CHS) is a dendritic cell (DC)-dependent T-cell-mediated inflammation with CD8+ T cells as effectors and CD4+ T cells as regulators (Treg cells) that models human allergic contact dermatitis. The integrin αE(CD103) is expressed by some T-cell and DC subsets and has been implicated in epithelial lymphocyte localization, but its role in immune regulation remains enigmatic. We have identified a function for CD103 in the development of cutaneous allergic immune responses. CHS responses, but not irritant contact dermatitis, were significantly augmented in CD103-deficient mice in hapten-challenged skin. Phenotype and function of skin DCs during sensitization were normal, whereas adoptive transfer experiments revealed that the elevated CHS response in CD103-deficient mice is transferred by primed T cells and is independent of resident cells in recipient mice. While T-cell counts were elevated in challenged skin of CD103-deficient mice, the FoxP3 expression level of CD4+CD25+ Treg cells was significantly reduced, indicating impaired functionality. Indeed, Treg cells from CD103-deficient mice were not able to suppress CHS reactions during the elicitation phase. Further, CD103 on FoxP3+ Treg cells was involved in Treg retention to inflamed skin. These findings indicate an unexpected dichotomous functional role for CD103 on Treg cells by modulating FoxP3 expression