13,187 research outputs found
A Cognitive Model of an Epistemic Community: Mapping the Dynamics of Shallow Lake Ecosystems
We used fuzzy cognitive mapping (FCM) to develop a generic shallow lake
ecosystem model by augmenting the individual cognitive maps drawn by 8
scientists working in the area of shallow lake ecology. We calculated graph
theoretical indices of the individual cognitive maps and the collective
cognitive map produced by augmentation. The graph theoretical indices revealed
internal cycles showing non-linear dynamics in the shallow lake ecosystem. The
ecological processes were organized democratically without a top-down
hierarchical structure. The steady state condition of the generic model was a
characteristic turbid shallow lake ecosystem since there were no dynamic
environmental changes that could cause shifts between a turbid and a clearwater
state, and the generic model indicated that only a dynamic disturbance regime
could maintain the clearwater state. The model developed herein captured the
empirical behavior of shallow lakes, and contained the basic model of the
Alternative Stable States Theory. In addition, our model expanded the basic
model by quantifying the relative effects of connections and by extending it.
In our expanded model we ran 4 simulations: harvesting submerged plants,
nutrient reduction, fish removal without nutrient reduction, and
biomanipulation. Only biomanipulation, which included fish removal and nutrient
reduction, had the potential to shift the turbid state into clearwater state.
The structure and relationships in the generic model as well as the outcomes of
the management simulations were supported by actual field studies in shallow
lake ecosystems. Thus, fuzzy cognitive mapping methodology enabled us to
understand the complex structure of shallow lake ecosystems as a whole and
obtain a valid generic model based on tacit knowledge of experts in the field.Comment: 24 pages, 5 Figure
Participatory Ecosystem Management Planning at Tuzla Lake (Turkey) Using Fuzzy Cognitive Mapping
A participatory environmental management plan was prepared for Tuzla Lake,
Turkey. Fuzzy cognitive mapping approach was used to obtain stakeholder views
and desires. Cognitive maps were prepared with 44 stakeholders (villagers,
local decisionmakers, government and non-government organization (NGO)
officials). Graph theory indices, statistical methods and "What-if" simulations
were used in the analysis. The most mentioned variables were livelihood,
agriculture and animal husbandry. The most central variable was agriculture for
local people (villagers and local decisionmakers) and education for NGO &
Government officials. All the stakeholders agreed that livelihood was increased
by agriculture and animal husbandry while hunting decreased birds and wildlife.
Although local people focused on their livelihoods, NGO & Government officials
focused on conservation of Tuzla Lake and education of local people.
Stakeholders indicated that the conservation status of Tuzla Lake should be
strengthened to conserve the ecosystem and biodiversity, which may be
negatively impacted by agriculture and irrigation. Stakeholders mentioned salt
extraction, ecotourism, and carpet weaving as alternative economic activities.
Cognitive mapping provided an effective tool for the inclusion of the
stakeholders' views and ensured initial participation in environmental planning
and policy making.Comment: 43 pages, 4 figure
Big data analytics:Computational intelligence techniques and application areas
Big Data has significant impact in developing functional smart cities and supporting modern societies. In this paper, we investigate the importance of Big Data in modern life and economy, and discuss challenges arising from Big Data utilization. Different computational intelligence techniques have been considered as tools for Big Data analytics. We also explore the powerful combination of Big Data and Computational Intelligence (CI) and identify a number of areas, where novel applications in real world smart city problems can be developed by utilizing these powerful tools and techniques. We present a case study for intelligent transportation in the context of a smart city, and a novel data modelling methodology based on a biologically inspired universal generative modelling approach called Hierarchical Spatial-Temporal State Machine (HSTSM). We further discuss various implications of policy, protection, valuation and commercialization related to Big Data, its applications and deployment
Improving Projects Performance With Lean Construction: State Of The Art, Applicability And Impacts
Construction projects are not often delivered on time and on budget and re-workings are usually required to satisfy customer’s needs. This papers aims to present an overview of Lean Construction (LC) and how this construction philosophy tackles the aforementioned problems. The research is empirical and based on data from the literature, 7 new Case Studies built with primary data, 12 Case Studies on CLIP (Construction Lean Improvement Programme) projects, 4 semi-structured Interviews with Firms adopting LC and several interviews (face to face and email) with LC experts. The results show as LC can achieve astonishing results focusing on reducing waste caused by unpredictable work-flow, paying attention on how every single activity affects the next one and avoiding reworking considered as no valued-added activity. The paper provides three original set of results: (1) a fuzzy cognitive map of LC showing how the different elements are linked to each other; (2) a pathway for the implementation of LC; (3) a synthesis of the strengths and the weaknesses of LC merging literature review with case studies analysis. In particular (3) shows the dimensions of projects adequate for lean construction, the increase of productivity and time reduction due to LC implementation and finally the reasons moving firms to adopt LC
Hydrothermal processing of biogenic residues in Germany: A technology assessment considering development paths by 2030
The mining, processing, and use of finite natural resources is associated with significant interventions in the natural environment. Thus, these and other negative consequences make it necessary to reduce resource consumption. An important field of action is the more efficient use of biogenic residues as secondary raw materials. However, high water containing biomasses are still a problem since they need an energy- and cost-intensive pre-treatment for many conversion processes, which can make their use uneconomical. Hydrothermal processes (HTP) seem to be promising, since they require an aqueous environment for optimal processing anyway. Although technological progress within the industry is recognisable, however, to date HTP have not been established in industrial continuous operation in Germany. The core of this work is identifying reasons for this sluggish development and deriving appropriate recommendations for action.
Based on the hypothesis that HTP can contribute to the efficient utilisation of biogenic residues in the future, potentials and obstacles for the development of HTP in Germany are identified using a literature review, expert survey, expert workshop, and SWOT analysis. To estimate the future potential of HTP in a systematic and structured way, a multi-criteria technology assessment approach is developed based on the results. To this end, assessment criteria for HTP are derived, weighted by expert judgment, and integrated into a transparent and structured procedure. In addition, mainly based on a Delphi-survey key factors of HTP development by 2030 in Germany are identified and three development alternatives for HTP in Germany by 2030 are derived. Using a system analysis and a comparative multi-criteria analysis at plant level, these scenarios are analysed for their possible future impact.
Based on this methodology, the work shows that the production costs for the end products, the energy efficiency of the process, and the proportion of recycled
phosphorus are of high relevance to the techno-economic success of HTP compared to reference systems, and they are therefore of high importance for its future development on the plant level. In addition, further key factors for the future development of HTP in Germany on the system level are found to be mainly in the political-legal (e.g. legal waste status of products from HTP) and techno-economic (e.g. cost-effective process water treatment) areas. According to this, important fields of action are the identification and use of cost reduction potentials (e.g. heat waste use), the development of system integrated decentralised plant concepts with integrated nutrient recycling (e.g. phosphorus), and the development of cost-effective ways to treat process water. System integration, cost-effective process water treatment, and nutrient recycling are all closely linked to production costs, investment costs, and potential revenues, and can contribute to improved process economics. For these areas, there is promising future potential to achieve higher competitiveness with reference technologies that are currently more economical.:Bibliographic description
Curriculum Vitae
Selbstständigkeitserklärung
Danksagung
List of Publications
Contribution to the Publications
Contents
List of Acronyms
List of Tables
List of Figures
Part I Introductory Chapters
1 Introduction and Background
Hydrothermal processes: Introduction and status quo
State of the art in the research field and knowledge gaps
Objective and research framework
Expected value added of this work
2 Materials and methods
Derivation of HTP evaluation metrics and technology assessment tool
Derivation of key HTP development factors and scenarios
Performing the system-level scenario analysis
Plant-level scenario analysis and test application of the assessment tool
Derivation of core recommendations
3 Results and discussion
Key development factors for HTP in Germany and scenarios
System-level scenario analysis
Test application of the assessment tool on plant level scenarios
Recommendations
Discussion
4 Conclusion and outlook
Future research
Further fields for the application of the developed methods
5 References
Part II Appended Articles
Paper I
Paper II
Paper III
Paper IV
Paper V
Paper VIDer Abbau, die Verarbeitung und die Nutzung endlicher natürlicher Ressourcen sind mit erheblichen Eingriffen in die natürliche Umwelt verbunden. Diese und andere negative Folgen machen es daher erforderlich, den Ressourcenverbrauch zu senken. Ein wichtiges Handlungsfeld ist die effizientere Nutzung biogener Reststoffe als Sekundärrohstoffe. Stark wasserhaltige Biomassen sind jedoch ein Problem, da sie für viele Umwandlungsprozesse eine energie- und kostenintensive Vorbehandlung benötigen, was ihre Verwendung unwirtschaftlich machen kann. Hydrothermale Prozesse (HTP) scheinen für diese Reststoffe allerdings vielversprechend zu sein, da sie ohnehin eine wässrige Umgebung für eine optimale Verarbeitung benötigen. Obwohl der technologische Fortschritt innerhalb der Branche erkennbar ist, wurde HTP in Deutschland bisher nicht im industriellen Dauerbetrieb etabliert. Der Kern dieser Arbeit besteht darin, Gründe für diese schleppende Entwicklung zu ermitteln und geeignete Handlungsempfehlungen abzuleiten.
Basierend auf der Hypothese, dass HTP in Zukunft zur effizienten Nutzung biogener Reststoffe beitragen können, werden Potenziale und Hindernisse für deren Entwicklung in Deutschland anhand einer Literaturrecherche, einer Expertenumfrage, eines Expertenworkshops und einer SWOT-Analyse ermittelt. Um das zukünftige Potenzial von HTP systematisch und strukturiert abzuschätzen, wird basierend auf den Ergebnissen ein multi-kriterieller Technologiebewertungsansatz entwickelt. Zu diesem Zweck werden Bewertungskriterien für HTP abgeleitet, nach Expertenmeinung gewichtet und in ein transparentes und strukturiertes Verfahren integriert. Darüber hinaus werden hauptsächlich auf der Grundlage einer Delphi-Umfrage Schlüsselfaktoren für die HTP-Entwicklung bis 2030 in Deutschland identifiziert und drei Entwicklungsalternativen für HTP in Deutschland bis 2030 abgeleitet. Mithilfe einer Systemanalyse und einer vergleichenden multi-kriteriellen Analyse auf Anlagenebene werden diese Szenarien auf ihre möglichen zukünftigen Auswirkungen hin analysiert.
Basierend auf dieser Methodik zeigen sich als Ergebnisse, dass die Produktionskosten für die Endprodukte, die Energieeffizienz der Prozesse und der Anteil an recyceltem Phosphor für den techno-ökonomischen Erfolg von HTP im Vergleich zu Referenzsystemen von hoher Relevanz und daher auch von hoher Bedeutung für die zukünftige Entwicklung auf Anlagenebene sind. Darüber hinaus liegen weitere Schlüsselfaktoren für die künftige Entwicklung von HTP in Deutschland auf Systemebene hauptsächlich im politisch-rechtlichen (z. B. legalen Abfallstatus von Produkten aus HTP) und techno-ökonomischen (z. B. kostengünstige Prozesswasseraufbereitung)) Bereichen. Wichtige Handlungsfelder sind demnach die Ermittlung und Nutzung von Kostensenkungspotentialen (zB Abwärmenutzung), die Entwicklung systemintegrierter dezentraler Anlagenkonzepte mit integriertem Nährstoffrecycling (z.B. Phosphor) und die Entwicklung kostengünstiger Wege zur Prozesswasserbehandlung. Systemintegration, kostengünstige Prozesswasseraufbereitung und Nährstoffrecycling hängen eng mit Produktionskosten, Investitionskosten und potenziellen Einnahmen zusammen und können zu einer verbesserten Wirtschaftlichkeit der Prozesse beitragen. Für diese Bereiche besteht ein vielversprechendes Zukunftspotenzial für eine höhere Wettbewerbsfähigkeit zu Referenztechnologien, die derzeit noch wirtschaftlicher sind.:Bibliographic description
Curriculum Vitae
Selbstständigkeitserklärung
Danksagung
List of Publications
Contribution to the Publications
Contents
List of Acronyms
List of Tables
List of Figures
Part I Introductory Chapters
1 Introduction and Background
Hydrothermal processes: Introduction and status quo
State of the art in the research field and knowledge gaps
Objective and research framework
Expected value added of this work
2 Materials and methods
Derivation of HTP evaluation metrics and technology assessment tool
Derivation of key HTP development factors and scenarios
Performing the system-level scenario analysis
Plant-level scenario analysis and test application of the assessment tool
Derivation of core recommendations
3 Results and discussion
Key development factors for HTP in Germany and scenarios
System-level scenario analysis
Test application of the assessment tool on plant level scenarios
Recommendations
Discussion
4 Conclusion and outlook
Future research
Further fields for the application of the developed methods
5 References
Part II Appended Articles
Paper I
Paper II
Paper III
Paper IV
Paper V
Paper V
Developing a green city assessment system using cognitive maps and the Choquet integral
Equitable human well-being and environmental concerns in urban areas have, over the years, become increasingly challenging issues. This trend is related to both the complexity inherent in the multiple factors to be considered when evaluating eco-friendly cities (i.e., green cities) and the way this type of city’s sustainability depends on many evaluation criteria, which hampers all decision-making processes. Using a multiple criteria decision analysis (MCDA) approach, this study sought to develop a multiple-criteria model that facilitates the evaluation of green cities’ sustainability, based on cognitive mapping techniques and the Choquet integral (CI). Taking a constructivist and process-oriented stance, the research included identifying evaluation criteria and their respective interactions using a panel of experts with specialized knowledge in the subject under analysis. The resulting framework and its application were validated both by the panel members and a parliamentary representative of the Portuguese ecology party “Os Verdes” (The Greens), who confirmed that the evaluation system created distinguishes between cities according to how strongly they adhere to “green” principles. The advantages and limitations of the proposed framework are also discussed.info:eu-repo/semantics/acceptedVersio
Development of Adaptive Environmental Management System: A Participatory Approach through Fuzzy Cognitive Maps
Conference ProceedingsMining industries develop environmental management systems/plans to
mitigate the impact their operations has on the society. Even with these plans, there
are still issues of pollution affecting the society. Though there are ICT-based
pollution monitoring solutions, their use is dismal due to lack of appreciation or
understanding of the disseminated information. This result in mining communities
depending on their own local knowledge to observe, monitor and predict miningrelated
environmental pollution. However, this local knowledge has never been
tested scientifically or analysed to recognize its usability or effectiveness. Mining
companies tend to ignore this knowledge from the communities as it is treated like
common information with no much scientific value. As a step towards verifying or
validating this local knowledge, we demonstrate how fuzzy cognitive maps can be
used to model, analyse and represent this linguistic local knowledge
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