960 research outputs found

    Concepts for the application of versioned object models in the building industry

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    Bauwerke sind in der Regel Unikate, fĂŒr die meist eine komplette und aufwĂ€ndige Neuplanung durchzufĂŒhren ist. Der Umfang und die Verschiedenartigkeit der einzelnen Planungsaufgaben bedingen ein paralleles Arbeiten der beteiligten Fachplaner. DarĂŒber hinaus ist die Bauplanung ein kreativer und iterativer Prozess, der durch hĂ€ufige Änderungen des Planungsmaterials und Abstimmungen zwischen den Fachplanern gekennzeichnet ist. Mithilfe von speziellen Fachanwendungen erstellen die Planungsbeteiligten verschiedene Datenmodelle, zwischen denen fachliche AbhĂ€ngigkeiten bestehen. Ziel der Arbeit ist es, die Konsistenz der einzelnen Fachmodelle eines Bauwerks sicherzustellen, indem AbhĂ€ngigkeiten auf Basis von Objektversionen definiert werden. Voraussetzung dafĂŒr ist, dass die Fachanwendungen nach dem etablierten Paradigma der objektorientierten Programmierung entwickelt wurden. Das sequentielle und parallele Arbeiten mehrerer Fachplaner wird auf Basis eines optimistischen Zugriffsmodells unterstĂŒtzt, das ohne Schreibsperren auskommt. Weiterhin wird die Historie des Planungsmaterials gespeichert und die Definition von rechtsverbindlichen FreigabestĂ€nden ermöglicht. Als Vorbild fĂŒr die Systemarchitektur diente das Softwarekonfigurationsmanagement, dessen Versionierungsansatz meist auf einem Client-Server-Modell beruht. Die formale Beschreibung des verwendeten Ansatzes wird ĂŒber die Mengenlehre und Relationenalgebra vorgenommen, so dass er allgemeingĂŒltig und technologieunabhĂ€ngig ist. Auf Grundlage dieses Ansatzes werden Konzepte fĂŒr den Einsatz versionierter Objektmodelle im Bauwesen erarbeitet und mit einer Pilotimplementierung basierend auf einer Open-Source-Ingenieurplattform an einem praxisnahen Szenario verifiziert. Beim Entwurf der Konzepte wird besonderer Wert auf die Handhabbarkeit der Umsetzung gelegt. Das betrifft im Besonderen die hierarchische Strukturierung des Projektmaterials, die ergonomische Gestaltung der Benutzerschnittstellen und der Erzielung von geringen Anwortzeiten. Diese Aspekte sind eine wichtige Voraussetzung fĂŒr die Effizienz und Akzeptanz von Software im praktischen Einsatz. Bestehende Fachanwendungen können durch geringen Entwicklungsaufwand einfach in die verteilte Umgebung integriert werden, ohne sie von Grund auf programmieren zu mĂŒssen.Structures are normally unique which often require a new, complete and complex design. The extensiveness and diverseness of the several planning tasks cause a parallel work of the involved planners. Furthermore, the building planning is a creative and iterative process that is characterised by frequent changes of the planning material and coordinations between the professional designers. The planners create different data models with dependencies between each other. The aim of this thesis is to ensure the consistency of the particular expert models by defining dependencies on the basis of object versions. A prerequisite is the development of all specialised applications with the established object-oriented programming paradigm. The sequential and parallel work of many planners is supported by an optimistic access model that does not require write locks. The history of the planning material will be stored additionally and the definition of release states is provided. The software configuration management served as a model for the system architecture whose versioning approach often relies on the client-server concept. The formal description of the used approach is done by the usage of the set theory and relational algebra to ensure its generality and independency from technologies. On the basis of this approach concepts for the application of versioned object models in civil engineering are formulated and verified at a practical scenario with a pilot implementation based on an open source engineering platform. A great importance was attached on the usability of the implementation. This affects especially the structuring of the project material, the ergonomic design of the user interface as well as the achievement of short response times. These aspects are a precondition for the efficiency and acceptance of the software by the practical users. Existing expert applications can be easily integrated in the distributed environment without programming them from scratch

    Concepts for the application of versioned object models in the building industry

    Get PDF
    Bauwerke sind in der Regel Unikate, fĂŒr die meist eine komplette und aufwĂ€ndige Neuplanung durchzufĂŒhren ist. Der Umfang und die Verschiedenartigkeit der einzelnen Planungsaufgaben bedingen ein paralleles Arbeiten der beteiligten Fachplaner. DarĂŒber hinaus ist die Bauplanung ein kreativer und iterativer Prozess, der durch hĂ€ufige Änderungen des Planungsmaterials und Abstimmungen zwischen den Fachplanern gekennzeichnet ist. Mithilfe von speziellen Fachanwendungen erstellen die Planungsbeteiligten verschiedene Datenmodelle, zwischen denen fachliche AbhĂ€ngigkeiten bestehen. Ziel der Arbeit ist es, die Konsistenz der einzelnen Fachmodelle eines Bauwerks sicherzustellen, indem AbhĂ€ngigkeiten auf Basis von Objektversionen definiert werden. Voraussetzung dafĂŒr ist, dass die Fachanwendungen nach dem etablierten Paradigma der objektorientierten Programmierung entwickelt wurden. Das sequentielle und parallele Arbeiten mehrerer Fachplaner wird auf Basis eines optimistischen Zugriffsmodells unterstĂŒtzt, das ohne Schreibsperren auskommt. Weiterhin wird die Historie des Planungsmaterials gespeichert und die Definition von rechtsverbindlichen FreigabestĂ€nden ermöglicht. Als Vorbild fĂŒr die Systemarchitektur diente das Softwarekonfigurationsmanagement, dessen Versionierungsansatz meist auf einem Client-Server-Modell beruht. Die formale Beschreibung des verwendeten Ansatzes wird ĂŒber die Mengenlehre und Relationenalgebra vorgenommen, so dass er allgemeingĂŒltig und technologieunabhĂ€ngig ist. Auf Grundlage dieses Ansatzes werden Konzepte fĂŒr den Einsatz versionierter Objektmodelle im Bauwesen erarbeitet und mit einer Pilotimplementierung basierend auf einer Open-Source-Ingenieurplattform an einem praxisnahen Szenario verifiziert. Beim Entwurf der Konzepte wird besonderer Wert auf die Handhabbarkeit der Umsetzung gelegt. Das betrifft im Besonderen die hierarchische Strukturierung des Projektmaterials, die ergonomische Gestaltung der Benutzerschnittstellen und der Erzielung von geringen Anwortzeiten. Diese Aspekte sind eine wichtige Voraussetzung fĂŒr die Effizienz und Akzeptanz von Software im praktischen Einsatz. Bestehende Fachanwendungen können durch geringen Entwicklungsaufwand einfach in die verteilte Umgebung integriert werden, ohne sie von Grund auf programmieren zu mĂŒssen.Structures are normally unique which often require a new, complete and complex design. The extensiveness and diverseness of the several planning tasks cause a parallel work of the involved planners. Furthermore, the building planning is a creative and iterative process that is characterised by frequent changes of the planning material and coordinations between the professional designers. The planners create different data models with dependencies between each other. The aim of this thesis is to ensure the consistency of the particular expert models by defining dependencies on the basis of object versions. A prerequisite is the development of all specialised applications with the established object-oriented programming paradigm. The sequential and parallel work of many planners is supported by an optimistic access model that does not require write locks. The history of the planning material will be stored additionally and the definition of release states is provided. The software configuration management served as a model for the system architecture whose versioning approach often relies on the client-server concept. The formal description of the used approach is done by the usage of the set theory and relational algebra to ensure its generality and independency from technologies. On the basis of this approach concepts for the application of versioned object models in civil engineering are formulated and verified at a practical scenario with a pilot implementation based on an open source engineering platform. A great importance was attached on the usability of the implementation. This affects especially the structuring of the project material, the ergonomic design of the user interface as well as the achievement of short response times. These aspects are a precondition for the efficiency and acceptance of the software by the practical users. Existing expert applications can be easily integrated in the distributed environment without programming them from scratch

    How one small step for occupational health management leads to many steps for employees – an experimental field study of incentive designs in a gamified mHealth app

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    Physical inactivity has become one of the leading health risk factors in today\u27s work environment, and in response, companies show increasing interest in digital health interventions to promote employees\u27 well-being. Tools such as mHealth apps use promising approaches to encourage people to be more physically active, for example, through gamification elements combined with financial incentives. However, there is a lack of research on how these technologies and incentives need to be designed to affect employees\u27 health behaviour positively. Based on prospect theory, this study examines the effect of gamified loss-oriented vs gain-oriented financial incentive systems with identical economic value to promote physical activity of employees. Our experiment\u27s results showed an overall positive effect in increasing employees\u27 physical activity (mean daily step count); more specifically, the advantage of a loss-oriented versus a gain-oriented incentive strategy compared to the control group

    Water hyacinth (Eichhornia crassipes), any opportunities for the Alaotra wetlands and livelihoods?

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    Species invasions are one of the world’s most severe conservation threats. The invasive water hyacinth (Eichhornia crassipes) is one of the most troublesome plants in the world. It appears in over 50 tropical and subtropical countries. This plant species causes several ecological and socioeconomic problems affecting ecosystems and local livelihoods. The water hyacinth occurs in the Alaotra wetlands encompassing the largest lake of Madagascar. The Alaotra region is renowned as Madagascar’s bread basket as it is the biggest rice and inland fish producer. The current study collected socioeconomic data from the Alaotra wetland stakeholders within three locations around Lake Alaotra to contextualize local livelihoods and to identify the drivers and barriers for the utilization of this plant. Methods of control seem to be unrealistic due to institutional and financial limitations in Madagascar. Using the plant as fertilizer, animal fodder or for handicrafts seems to represent a feasible alternative to improve the livelihood of the local population. However, local concerns about livelihood security may hinder acceptance of such new alternatives. Providing information as well as financial and technical support to local stakeholders may help encourage the use of the water hyacinth in the Alaotra region

    An alternative for agriculture at Lake Alaotra, Madagascar: organic fertilizer and soil amendment from the invasive water hyacinth (Eichhornia crassipes)

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    In the context of a globally increasing human population coupled with continuous environmental degradation, eco-friendly agricultural innovations are essential to reduce poverty and food insecurity in the world. This is particularly evident in developing countries where nature conservation and agricultural production remain in conflict. We investigated the effectiveness of using a locally free natural resource, the invasive plant species water hyacinth (Eichhornia crassipes), as a source for organic fertilizer and soil amendment (composts, green manure and ash) at Lake Alaotra, one of the most important agricultural areas of Madagascar. Five different products were produced under the local conditions of Lake Alaotra. In addition, we conducted a growth experiment with Chinese cabbage (Brassica rapa ssp. chinensis) to evaluate the effectiveness of the water hyacinth products in comparison to the mineral fertilizer NPK—nitrogen, phosphorous, potassium—and to cow dung. The results of our study show that it was easily possible to produce water hyacinth fertilizer/soil amendment under the remote conditions of Lake Alaotra. In addition, our results show that a higher biomass gain of Chinese cabbage treated with water hyacinth composts was achieved compared to NPK and cow dung. A higher biomass gain was mainly obtained due to an improvement of soil structure after compost addition. Water hyacinth green manure and ash showed low performance. Besides, applying composts was cheaper than buying NPK or cow dung. Our results show that water hyacinth can serve as a fertilizer and soil amendment and could help to improve agriculture at Lake Alaotra. RĂ©sumĂ©Dans un contexte d’accroissement mondial de la population humaine couplĂ© d’une dĂ©gradation continue de l’environnement, les innovations agriculturales respectueuses de l’environnement sont essentielles pour rĂ©duire la pauvretĂ© et l’insĂ©curitĂ© alimentaire mondiale. Cette situation est particuliĂšrement Ă©vidente au niveau des pays en voie de dĂ©veloppement oĂč la conservation de la nature et la production agricole sont en constant conflit. Nous avons Ă©tudiĂ© l’efficacitĂ© de l’usage d’une ressource naturelle locale, la plante envahissante jacinthe d’eau (Eichhornia crassipes) comme source de fertilisant organique (composts, engrais vert et cendre) au niveau du Lac Alaotra, une des plus importantes zones agricoles de Madagascar. Cinq types de fertilisants ont Ă©tĂ© produits Ă  partir de la jacinthe d’eau selon les conditions locales du Lac Alaotra. De plus, nous avons conduit une expĂ©rience avec le chou de chine (Brassica rapa, ssp. chinensis) pour Ă©valuer les performances des fertilisants de la jacinthe d’eau en comparaison avec les fertilisants locaux NPK (11% d’azote, 22% de phosphore et 16% de potassium) et le fumier de bĂ©tail. Nos rĂ©sultats montrent que la production de fertilisants Ă  partir de la jacinthe d’eau et son usage pour l’amendement du sol sont possibles et faciles Ă  rĂ©aliser dans les conditions locales. De plus, un gain de biomasse important a Ă©tĂ© observĂ© avec les choux traitĂ©s avec les composts de jacinthe d’eau en comparaison avec le NPK et le fumier de bĂ©tail. L’important gain de biomasse est certainement dĂ» Ă  l’amĂ©lioration de la structure du sol aprĂšs l’application du compost. L’engrais vert et les cendres de jacinthe d’eau ont montrĂ© cependant de maigres performances. De plus, l’utilisation du compost est moins chĂšre par rapport Ă  celle du NPK et du fumier de bĂ©tail. Nos rĂ©sultats montrent que la jacinthe d’eau peut ĂȘtre appliquĂ©e en tant que fertilisant et pour l’amendement du sol, et par consĂ©quent peut contribuer Ă  l’amĂ©lioration de l’agriculture au niveau du Lac Alaotra

    Late Life-Threatening Hemorrhage after Percutaneous Tracheostomy

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    Purpose. Formation of a tracheoinnominate artery fistula (TIF) and consecutive hemorrhage is a rare and life-threatening complication with high mortality. Warning symptoms can be absent. The current literature contains only few considerations for misleading signs, especially in cases where the contact between the tissue and the cannula is tight. Method and Results. We report two cases of life-threatening hemorrhages that appeared six days and two months after percutaneous dilatational tracheostomy (PDT) in two patients, respectively. In these cases, diagnosis of tracheoinnominate artery fistula (TIF) was difficult. Tracheal ring fracture after PDT and pressure ulceration caused by cannula were implicated in TIF formation. The cannula was overblocked to buy time before surgical closure. Both patients survived without any additional neurological deficiency. Conclusion. Massive hemorrhage in patients after tracheostomy is likely due to TIF. Ultrasound scanning before PDT and careful periodical followup of the trachea are required

    Lake Alaotra wetlands: how long can Madagascar's most important rice and fish production region withstand the anthropogenic pressure?

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    The Alaotra wetlands represent the biggest lake and wetland complex in Madagascar and are home of several endemic species. The region constitutes the largest rice production area and inland fishery of Madagascar. Rice and fish are the main local sources of income. While the population has increased fivefold during the last 40 years, the growing need for resources is continuously increasing the pressure on the wetland system. In this study, vegetation and water parameters were collected within three sites differing by level of degradation in order to evaluate the current ecological state of the wetland. The results show that high levels of ongoing anthropogenic disturbance are favoring the formation of a new plant community in the fringe area of the marsh belt. This area is now dominated by invasive species such as the water hyacinth (Eichhornia crassipes) which shows a mean coverage up to 53% and water ferns (Salvinia spp.) with a mean coverage up to 31 .4%. Lake water levels were very low and decreased during the dry season to a mean level of only 3 cm in the littoral zone. Signs of eutrophication like hypoxia (mean saturation of only 22%), increased phosphate concentrations (1 .1 8 mg L-1 ) and black colored, foul smelling water were observed. Under a likely scenario of growing anthropogenic pressures, it remains unclear what the current trends will bring for the wetland’s future
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