TY - THES A1 - Ciesla, Agnieszka T1 - “Shrinking city” in Eastern Germany. The Term in the context of urban development in Poland N2 - The aim of this doctoral thesis was to investigate whether the German term “shrinking city” is appropriate to depopulating Polish cities. In order to do so an attempt to define the currently still vague notion of “shrinking city” was made. The urban development of Eastern Germany was thoroughly examined both in a short term perspective and in a wide historical as well as international context, with the Polish urban development used as reference. 25 cities (kreisfreie Städte) in Eastern Germany and depopulating Polish cities: Łódź and the Metropolis Silesia were chosen as case studies. On the basis of the gathered information a “shrinking city” in Eastern Germany was defined as a city with a long-lasting population decrease coupled with over-dimensioned, growth-oriented development policies carried out for decades. Such a development path is triggering negative consequences in the spatial, economic and also demographic dimension, which tend to intensify each other. The thesis postulates that the definition of the “shrinking city in Eastern Germany” is not appropriate to depopulating cities in Poland. Polish cities are characterized by a short-lasting population decrease and this trend is not triggering negative spatial and economic consequences. Oversized growth development policies were never present in the cities and they still suffer from great deficiencies in housing and other basic infrastructure, which derive from the socialist period. Furthermore, radical de-economization, known from Eastern German cities, did not occur in the Polish cities. Both Łódź and the Metropolis Silesia remain main production centers of the country. This doctoral thesis presents a contradictory view to contemporary publications on “shrinking cities”, in which this phenomenon is regarded as having occurred suddenly after the collapse of the socialism. It proved that “shrinking cities” in Eastern Germany are not the outcome of short-lasting processes, but are deeply rooted in the past. Moreover, they represent a very distinct development pattern that highly differentiates from the one found in Central Eastern Europe and the one in Western Europe. In this way the doctoral thesis provided a new, critical approach to the discourse on “shrinking cities” in Germany. It also draws attention to the importance of the historical analysis in cities’ development research, particularly in cross border studies. In time of European integration peculiarities resulting from centuries of different spatial, economic and social development paths should not be underestimated. KW - shrinking city KW - Stadtplanung KW - urban development KW - Central and Eastern Europe KW - demography KW - spatial development KW - economic development KW - socialist city KW - post-socialist city Y1 - 2013 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20130325-18694 ER - TY - THES A1 - Long, Jiang T1 - The spatial formation and transformation of Chinese rural clan settlements : A case study of Furong and Cangpo villages in Wenzhou, Zhejiang Province, China N2 - This dissertation attempts to describe, analyze and evaluate how the settlement spaces of Chinese clans in rural areas were shaped by local clan lives in ancient times and transformed along with the transition of those clan organizations in modern China. In approaching this subject, two major questions are raised: what was the role of ancient Chinese rural clans in the spatial formation of their settlements and, nowadays, do they still play the same role as before? To approach these answers, this dissertation sets out to draw on systematically interdisciplinary research from the perspectives of socio-culture and architecture- planning to have an overall understanding of a Chinese clan organization and clan settlement. Then, the basic characteristics of traditional Chinese clans and their importance to the Chinese people are discussed by tracing the history and evolution of Chinese clan organizations in the dissertation. Two old villages, Furong and Cangpo in now Wenzhou, Zhejiang Province, are selected for case study research. And the research reveals that it was the clans that took charge of planning and managing the various construction activities, especially those of communal buildings and facilities, within their own settlements, and the clan lives exerted a decisive impact on shaping the settlement spaces, branding the characteristics of the clan lives clearly and deeply on the spaces. Following that, in the dissertation is described the transformation process of traditional Chinese clans in modern and contemporary China. The clan lives in rural areas have been reshaped and this exerts a great impact on clan settlement spaces. It is shown in the case studies of Furong and Cangpo. KW - Sattlement KW - Rural Area KW - Clan KW - Spatial formation KW - Spatial Transformation KW - Chinese rural clan settlement Y1 - 2013 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20130117-18187 ER - TY - THES A1 - Jakupi, Arta T1 - The Effect of the International Community Presence in the Urban Development of Post Conflict City Case Study: Kosova N2 - Post Conflict Reconstruction is a very complex topic, whether it is to be undertaken by the Local or the International Community. The process of the Post Conflict Development is to be very hard to investigate, primarily for the combination of socio-cultural phenomena, war and political instability; having difficulties of conducting solid empirical analysis (obtaining reliable data) and dealing with war-torn communities. The multifaceted process of the reconstruction is ought to touch a lot of countries vital segments, whereas each of them requires different approach; coordination with one another; and unification in their common aim. The emergency of the assistance programs are not equal, same as with the priority and weight when compared with each other, therefore occasionally there are programs for the success of which the other less important actions are violated or neglected. The case is with the International Community presence ( the set up), which aside from their mission and projects, it is considered to play a very important role on the urban development of a post conflict city; the setting was never planned or considered in a holistic manner, therefore IC establishment was done ad hoc and it was guided by issues which did not help at its greatest to the urban development of the city and more over to the citizens who were most in need. The study is about the Urban Development, due to the fact that the biggest concentration of the International Community is likely to be in the urban centers, and the experienced changes are of a much considerable magnitude. The reconstruction phase is likely to be lasting at about 10 years and more , consequently the International Community for that time being tends to be recognized as temporary citizens of the city, and it is inevitably that they will be having an impact on the urban development of the city; in that basis it is considered to be significant that the International Community Establishment/Set Up be included into the International Organizations mission and assist in the overall mission of the reconstruction. KW - urban development KW - Stadtplanung KW - urban planning KW - post-conflict KW - international organizations KW - Architektur KW - reconstruction Y1 - 2013 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20130130-18314 ER - TY - THES A1 - Seiffarth, Torsten T1 - Sorptionsverhalten von Cu2+ und NH4+ an Bentoniten unter Berücksichtigung von Nebengemengteilen sowie Strukturänderungen nach moderater Wärmebehandlung N2 - Bentonite sind quellfähige Tone, die häufig in der Umwelttechnik (in Abdichtungsbauwerken oder in der Bodensanierung) eingesetzt werden. Ziel der Arbeit war die Klärung, wie eine unterschiedliche Kationenbelegung mit Cu2+ und NH4+ die Eigenschaften der Bentonite bei Raumtemperatur und nach moderater Wärmebehandlung (300 – 450°C) beeinflusst. Im Blickpunkt stand insbesondere die gleichzeitige Präsenz von Kupfer- und Ammoniumionen, die als Vertreter für häufig auftretende Inhaltsstoffe von Wässern in der Umgebung von technischen Bentoniten ausgewählt wurden. Die Untersuchungen zur Cu2+-Sorption bei Raumtemperatur und nach moderater Wärmebehandlung (300 – 450°C) erfolgten an Pulverproben von zwei technischen Bentoniten, die sich in der ursprünglichen Kationenbelegung, Art und Anteil an Nebengemengteilen, sowie der Schichtladungsverteilung in den Montmorilloniten unterscheiden. Vor der Wärmebehandlung wurden die Bentonite durch Kontakt mit verschieden konzentrierten Kupfer- und Ammoniumlösungen mit unterschiedlichen Gehalten der Kationen Cu2+, NH4+, Na+, Ca2+, Mg2+ belegt. Der Eintrag von Kupferionen in die Bentonite durch Kationenaustausch bei Raumtemperatur wurde erwartungsgemäß durch präsente Nebengemengteile (wie Carbonat) beeinflusst, so dass die Kupferionen zusätzlich spezifisch adsorbiert und in festen Phasen angereichert wurden. Die Cu2+-Fixierung infolge der Wärmebehandlung wurde vom Cu2+-Totalgehalt in den Bentoniten, der Präsenz von Nebengemengteilen und die Schichtladungsverteilung in den Montmorilloniten beeinflusst. Es waren generell Behandlungstemperaturen von > 400°C erforderlich, um Cu2+-Fixierungsraten von > 95% zu erzielen. Waren während der Wärmebehandlung neben Cu2+-Ionen gleichzeitig NH4+-Ionen in den Bentoniten präsent, konnte die Cu2+-Fixierungstemperatur herabgesetzt werden. Die Deammonisierung (NH4+ --> NH3 + H+) der NH4+-belegten Bentonite fand größtenteils unterhalb der Dehydroxylierungstemperatur der Bentonite statt. Durch Untersuchungen (XRD, FTIR, NMR, ESR) zum Mechanismus der Cu2+-Einbindung in die Bentonite an speziell aufbereiteten Proben (carbonatfrei, < 2 µm) konnte nachgewiesen werden, dass in den Cu2+-belegten Montmorilloniten die Cu2+-Ionen infolge der Wärmebehandlung nicht bis in die Oktaederschicht der Tonminerale vordringen, sondern nur bis in die Tetraederschicht wandern. In den NH4+-belegten Montmorilloniten treten im Zusammenhang mit der Deammonisierung keine zusätzlichen Strukturänderungen (wie Auflösung der Oktaederschicht) infolge der Wärmebehandlung auf. KW - Bentonit KW - Montmorillonite KW - Kupfersilicate KW - Sorption KW - Wärmebehandlung KW - Kupferfixierung KW - Deammonisierung KW - Kationenaustausch KW - Ammonium-Ton KW - Mikrostruktur Y1 - 2013 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20130718-19791 ER - TY - THES A1 - Ahmad, Sofyan T1 - Reference Surface-Based System Identification N2 - Environmental and operational variables and their impact on structural responses have been acknowledged as one of the most important challenges for the application of the ambient vibration-based damage identification in structures. The damage detection procedures may yield poor results, if the impacts of loading and environmental conditions of the structures are not considered. The reference-surface-based method, which is proposed in this thesis, is addressed to overcome this problem. In the proposed method, meta-models are used to take into account significant effects of the environmental and operational variables. The usage of the approximation models, allows the proposed method to simply handle multiple non-damaged variable effects simultaneously, which for other methods seems to be very complex. The input of the meta-model are the multiple non-damaged variables while the output is a damage indicator. The reference-surface-based method diminishes the effect of the non-damaged variables to the vibration based damage detection results. Hence, the structure condition that is assessed by using ambient vibration data at any time would be more reliable. Immediate reliable information regarding the structure condition is required to quickly respond to the event, by means to take necessary actions concerning the future use or further investigation of the structures, for instance shortly after extreme events such as earthquakes. The critical part of the proposed damage detection method is the learning phase, where the meta-models are trained by using input-output relation of observation data. Significant problems that may encounter during the learning phase are outlined and some remedies to overcome the problems are suggested. The proposed damage identification method is applied to numerical and experimental models. In addition to the natural frequencies, wavelet energy and stochastic subspace damage indicators are used. T3 - ISM-Bericht // Institut für Strukturmechanik, Bauhaus-Universität Weimar - 2013,3 KW - System Identification KW - Schadensdetektionsverfahren KW - Referenzfläche Y1 - 2013 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20140205-21132 ER - TY - THES A1 - Moehring, Mathias T1 - Realistic Interaction with Virtual Objects within Arm's Reach N2 - The automotive industry requires realistic virtual reality applications more than other domains to increase the efficiency of product development. Currently, the visual quality of virtual invironments resembles reality, but interaction within these environments is usually far from what is known in everyday life. Several realistic research approaches exist, however they are still not all-encompassing enough to be usable in industrial processes. This thesis realizes lifelike direct multi-hand and multi-finger interaction with arbitrary objects, and proposes algorithmic and technical improvements that also approach lifelike usability. In addition, the thesis proposes methods to measure the effectiveness and usability of such interaction techniques as well as discusses different types of grasping feedback that support the user during interaction. Realistic and reliable interaction is reached through the combination of robust grasping heuristics and plausible pseudophysical object reactions. The easy-to-compute grasping rules use the objects’ surface normals, and mimic human grasping behavior. The novel concept of Normal Proxies increases grasping stability and diminishes challenges induced by adverse normals. The intricate act of picking-up thin and tiny objects remains challenging for some users. These cases are further supported by the consideration of finger pinches, which are measured with a specialized finger tracking device. With regard to typical object constraints, realistic object motion is geometrically calculated as a plausible reaction on user input. The resulting direct finger-based interaction technique enables realistic and intuitive manipulation of arbitrary objects. The thesis proposes two methods that prove and compare effectiveness and usability. An expert review indicates that experienced users quickly familiarize themselves with the technique. A quantitative and qualitative user study shows that direct finger-based interaction is preferred over indirect interaction in the context of functional car assessments. While controller-based interaction is more robust, the direct finger-based interaction provides greater realism, and becomes nearly as reliable when the pinch-sensitive mechanism is used. At present, the haptic channel is not used in industrial virtual reality applications. That is why it can be used for grasping feedback which improves the users’ understanding of the grasping situation. This thesis realizes a novel pressure-based tactile feedback at the fingertips. As an alternative, vibro-tactile feedback at the same location is realized as well as visual feedback by the coloring of grasp-involved finger segments. The feedback approaches are also compared within the user study, which reveals that grasping feedback is a requirement to judge grasp status and that tactile feedback improves interaction independent of the used display system. The considerably stronger vibrational tactile feedback can quickly become annoying during interaction. The interaction improvements and hardware enhancements make it possible to interact with virtual objects in a realistic and reliable manner. By addressing realism and reliability, this thesis paves the way for the virtual evaluation of human-object interaction, which is necessary for a broader application of virtual environments in the automotive industry and other domains. N2 - Stärker als andere Branchen benötigt die Automobilindustrie realistische Virtual Reality Anwendungen für eine effiziente Produktentwicklung. Während sich die visuelle Qualität virtueller Darstellungen bereits der Realität angenähert hat, ist die Interaktion mit virtuellen Umgebungen noch weit vom täglichen Erleben der Menschen entfernt. Einige Forschungsansätze haben sich mit realistischer Interaktion befasst, gehen aber nicht weit genug, um in industriellen Prozessen eingesetzt zu werden. Diese Arbeit realisiert eine lebensnahe mehrhändige und fingerbasierte Interaktion mit beliebigen Objekten. Dabei ermöglichen algorithmische und technische Verbesserungen eine realitätsnahe Usability. Außerdem werden Methoden für die Evaluation dieser Interaktionstechnik vorgestellt und benutzerunterstützende Greiffeedbackarten diskutiert. Die verlässliche und gleichzeitig realistische Interaktion wird durch die Kombination von robusten Greifheuristiken und pseudophysikalischen Objektreaktionen erreicht. Die das menschliche Greifverhalten nachbildenden Greifregeln basieren auf den Oberflächennormalen der Objekte. Die Reduktion negativer Einflüsse verfälschter Normalen und eine höhere Griffstabilität werden durch das neuartige Konzept der Normal Proxies erreicht. Dennoch bleibt für manche Nutzer das Aufnehmen von dünnen und kleinen Objekten problematisch. Diese Fälle werden zusätzlich durch die Einbeziehung von Fingerberührungen unterstützt, die mit einem speziellen Fingertracking Gerät erfasst werden. Plausible Objektreaktionen auf Benutzereingaben werden unter Berücksichtigung typischer Objekteinschränkungen geometrisch berechnet. Die Arbeit schlägt zwei Methoden zur Evaluierung der fingerbasierten Interaktion vor. Ein Expertenreview zeigt, dass sich erfahrene Benutzer sehr schnell in die Technik einfinden. In einer Benutzerstudie wird nachgewiesen, dass fingerbasierte Interaktion im hier untersuchten Kontext vor indirekter Interaktion mit einem Eingabegerät bevorzugt wird. Während letztere robuster zu handhaben ist, stellt die fingerbasierte Interaktion einen deutlich höheren Realismus bereit und erreicht mit den vorgeschlagenen Verbesserungen eine vergleichbare Verlässlichkeit. Um Greifsituationen transparent zu gestalten, realisiert diese Arbeit ein neuartiges druckbasiertes taktiles Feedback an den Fingerspitzen. Alternativ wird ein vibrotaktiles Feedback am gleichen Ort realisiert und visuelles Feedback durch die Einfärbung der griffbeteiligten Fingersegmente umgesetzt. Die verschiedenen Feedbackansätze werden in der Benutzerstudie verglichen. Dabei wird Greiffeedback als Voraussetzung identifiziert, um den Greifzustand zu beurteilen. Taktiles Feedback verbessert dabei die Interaktion unabhängig vom eingesetzten Display. Das merklich stärkere Vibrationsfeedback kann während der Interaktion störend wirken. Die vorgestellten Interaktionsverbesserungen und Hardwareerweiterungen ermöglichen es, mit virtuellen Objekten auf realistische und zuverlässige Art zu interagieren. Indem die Arbeit Realismus und Verlässlichkeit gleichzeitig adressiert, bereitet sie den Boden für die virtuelle Untersuchung von Mensch-Objekt Interaktionen und ermöglicht so einen breiteren Einsatz virtueller Techniken in der Automobilindustrie und in anderen Bereichen. KW - Virtuelle Realität KW - Interaktion KW - Mensch-Maschine-Interaktion KW - Medieninformatik Y1 - 2013 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20130301-18592 ER - TY - THES A1 - Alexander, Anne T1 - Quantitative Erfassung von Risiken und Simulation ihrer Auswirkungen auf den Verlauf eines Bauprojektes N2 - Das Bauwesen hat sich in den letzten Jahren durch die Globalisierung des Marktes verbunden mit einer verstärkten Nutzung moderner Technologien stark gewandelt. Die Planung und die Durchführung von Bauvorhaben werden zunehmend komplexer und sind mit erhöhten Risiken verbunden. Geld- und Zeitressourcen werden bei einem immer härter werdenden Konkurrenzkampf knapper. Das Projektmanagement stellt Lösungsansätze bereit, um Bauvorhaben auch unter erschwerten Bedingungen und erhöhten Risiken erfolgreich zum Abschluss zu bringen. Dabei hat ein systematisches Risikomanagement beginnend bei der Projektentwicklung bis zum Projektabschluss eine für den Projekterfolg entscheidende Bedeutung. Ziel der Arbeit ist es, eine quantitative Risikoerfassung für Projektmanager als professionelle Bauherrenvertretung und die Simulation der Risikoauswirkungen auf den Verlauf eines Projektes während der Planungs- und Bauphase zu ermöglichen. Mit Hilfe eines abstrakten Modells soll eine differenzierte, praxisnahe Simulation durchführbar sein, die die verschiedenen Arten der Leistungs- und Kostenentstehung widerspiegelt. Parallel dazu soll die Beschreibung von Risiken so abstrahiert werden, dass beliebige Risiken quantitativ erfassbar und anschließend ihre Auswirkungen inklusive mögliche Gegenmaßnahmen in das Modell integrierbar sind. Anhand zweier Beispiele werden die unterschiedlichen Einsatzmöglichkeiten der quantitativen Erfassung von Projektrisiken und der anschließenden Simulation ihrer Auswirkungen aufgezeigt. Bei dem ersten Beispiel, einem realen, bereits abgeschlossenen Schieneninfrastrukturprojekt, wird die Wirksamkeit einer vorbeugenden Maßnahme gegen ein Projektrisiko untersucht. Im zweiten Beispiel wird ein Planspielansatz zur praxisnahen Aus- und Weiterbildung von Projektmanagern entwickelt. Inhalt des Planspiels ist die Planung und Errichtung eines privatfinanzierten, öffentlichen Repräsentationsbaus mit teilweiser Fremdnutzung. T3 - Schriften der Professur Baubetrieb und Bauverfahren - 28 KW - Risiko KW - Projektmanagement KW - Planspiel KW - Simulationsmodell KW - Risikoerfassung KW - Projektmanagement KW - Simulationsmodell KW - Kosten- und Leistungsentwicklung KW - Planspiel Y1 - 2013 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20130927-20514 ER - TY - THES A1 - Nasser, Mourad T1 - Quality Assessment of Dynamic Soil-Structure Interaction Models Using Energy Measures N2 - In this research work, an energy approach is employed for assessing quality in dynamic soil-structure interaction (SSI) models, and energy measures are introduced and investigated as general indicators of structural response. Dynamic SSI models with various abstraction levels are then investigated according to different coupling scenarios for soil and structure models. The hypothesis of increasing model uncertainty with decreasing complexity is investigated and a mathematical framework is provided for the treatment of model uncertainty. This framework is applied to a case study involving alternative models for incorporating dynamic SSI effects. In the evaluation process, energy measures are used within the framework of the \textit{adjustment factor} approach in order to quantitatively assess the uncertainty associated with SSI models. Two primary types of uncertainty are considered, namely the uncertainty in the model framework and the uncertainty in the model input parameters. Investigations on model framework uncertainty show that the more complex three-dimensional FE model has the best quality of the models investigated, whereas the Wolf SSI model produces the lowest model uncertainty of the simpler models. The fixed-base model produces the highest estimated uncertainty and accordingly the worst quality of all models investigated. These results confirm the hypothesis of increasing model uncertainty with decreasing complexity only when the assessment is based on the ratio of structural hysteretic energy to input energy as a response indicator. T3 - Schriftenreihe des DFG Graduiertenkollegs 1462 Modellqualitäten // Graduiertenkolleg Modellqualitäten - 8 KW - soil-structure interaction KW - model assessment KW - structural energy KW - Boden-Bauwerk-Wechselwirkung Y1 - 2013 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20130220-18542 SN - 978-3-86068-494-8 PB - Verlag der Bauhaus-Universität CY - Weimar ER - TY - THES A1 - Jean-Baptiste, Nathalie T1 - People centered approach towards food waste management in the urban environment of Mexico N2 - A more careful consideration of food waste is needed for planning the urban environment. The research signals links between the organization of individuals, the built environment and food waste management through a study conducted in Mexico. It recognizes the different scales within which solid waste management operates, explores food waste production at household levels, and investigates the urban circumstances that influence its management. This is based on the idea that sustainable food waste management in cities requires a constellation of processes through which a ‘people centered’ approach offers added value to technical and biological facts. This distinction addresses how urban systems react to waste and what behavioral and structural factors affect current sanitary practices in Mexico. Food waste is a resource-demanding item, which makes for a considerable amount of refuse being disposed of in landfills in developing cities. The existing data shortage on waste generation at household levels debilitates implementation strategies and there is a need for more contextual knowledge associated with waste. The evidence-based study includes an explorative phase on the culture of waste management and a more in-depth examination of domestic waste composition. Mixed data collection tools including a household based survey, a food waste diary and weighing recording system were developed to enquire into the daily practices of waste disposal in households. The contrasting urban environment of Mexico City Metropolitan Area holds indistinctive boundaries between the core and the periphery, which hinder the implementation of integrated environmental plans. External determinants are different modes of urban transformation and internal determinants are building features and their consolidation processes. At the household level, less and more affluents groups responded differently to external environmental stressors. A targeted planning proposition is required for each group. Local alternative waste management is more likely to be implement in less affluent contexts. Further, more effective demand-driven service delivery implies better integration between the formal and informal sectors. The results show that efforts toward securing long-term changes in Mexico and other cities with similar circumstances require creating synergy between education, building consolidation, local infrastructure and social engagement. KW - Food Waste Management KW - Mexico KW - Urban Environment KW - People Approach KW - Food Waste Management KW - Latin America KW - Mexico KW - Social context KW - Built environment Y1 - 2013 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20131024-20633 CY - Weimar ER - TY - THES A1 - Lipka, Nedim T1 - Modeling Non-Standard Text Classification Tasks N2 - Text classification deals with discovering knowledge in texts and is used for extracting, filtering, or retrieving information in streams and collections. The discovery of knowledge is operationalized by modeling text classification tasks, which is mainly a human-driven engineering process. The outcome of this process, a text classification model, is used to inductively learn a text classification solution from a priori classified examples. The building blocks of modeling text classification tasks cover four aspects: (1) the way examples are represented, (2) the way examples are selected, (3) the way classifiers learn from examples, and (4) the way models are selected. This thesis proposes methods that improve the prediction quality of text classification solutions for unseen examples, especially for non-standard tasks where standard models do not fit. The original contributions are related to the aforementioned building blocks: (1) Several topic-orthogonal text representations are studied in the context of non-standard tasks and a new representation, namely co-stems, is introduced. (2) A new active learning strategy that goes beyond standard sampling is examined. (3) A new one-class ensemble for improving the effectiveness of one-class classification is proposed. (4) A new model selection framework to cope with subclass distribution shifts that occur in dynamic environments is introduced. KW - Text Classification KW - Machine Learning Y1 - 2013 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20130307-18626 ER -