An Approach to Improved Decentralized Design: The Modified Approximation-Based Decentralized Design (MADD) Framework

2007 ◽  
Author(s):  
Ashwin P. Gurnani ◽  
Kemper Lewis
Keyword(s):  
Nash Equilibrium ◽  
Bounded Rationality ◽  
Large Scale ◽  
Optimization Techniques ◽  
Objective Functions ◽  
Design Problems ◽  
Decentralized Design ◽  
The Impact ◽  
Rational Reaction Set

The design of large scale complex engineering systems requires interaction and communication between multiple disciplines and decentralized subsystems. One common fundamental assumption in decentralized design is that the individual subsystems only exchange design variable information and do not share objective functions or gradients. This is because the decentralized subsystems can either not share this information due to geographical constraints or choose not to share it due to corporate secrecy issues. Game theory has been used to model the interactions between distributed design subsystems and predict convergence and equilibrium solutions. These game theoretic models assume that designers make perfectly rational decisions by selecting solutions from their Rational Reaction Set (RRS), resulting in a Nash Equilibrium solution. However, empirical studies reject the claim that decision makers always make rational choices and the concept of Bounded Rationality is used to explain such behavior. In this paper, a framework is proposed that uses the idea of bounded rationality in conjunction with set-based design, metamodeling and multiobjective optimization techniques to improve solutions for convergent decentralized design problems. Through the use of this framework, entitled Modified Approximation-based Decentralized Design (MADD) framework, convergent decentralized design problems converge to solutions that are superior to the Nash equilibrium. A two subsystem mathematical problem is used as case study and simulation techniques are used to study the impact of the framework parameters on the final solution. The discipline specific objective functions within the case study problem are unconstrained and continuous — however, the implementation of the MADD framework is not restricted to such problems.

scholarly journals Multitemporal Mapping of Post-Fire Land Cover Using Multiplatform PRISMA Hyperspectral and Sentinel-UAV Multispectral Data: Insights from Case Studies in Portugal and Italy

Sensors ◽  
2021 ◽  
Vol 21 (12) ◽  
pp. 3982
Author(s):  
Giacomo Lazzeri ◽  
William Frodella ◽  
Guglielmo Rossi ◽  
Sandro Moretti
Keyword(s):  
Remote Sensing ◽  
Large Scale ◽  
Fire Severity ◽  
Experimental Methodology ◽  
Vegetation Recovery ◽  
Burned Area ◽  
Remotely Sensed Data ◽  
The Impact ◽  
Sentinel 2

Wildfires have affected global forests and the Mediterranean area with increasing recurrency and intensity in the last years, with climate change resulting in reduced precipitations and higher temperatures. To assess the impact of wildfires on the environment, burned area mapping has become progressively more relevant. Initially carried out via field sketches, the advent of satellite remote sensing opened new possibilities, reducing the cost uncertainty and safety of the previous techniques. In the present study an experimental methodology was adopted to test the potential of advanced remote sensing techniques such as multispectral Sentinel-2, PRISMA hyperspectral satellite, and UAV (unmanned aerial vehicle) remotely-sensed data for the multitemporal mapping of burned areas by soil–vegetation recovery analysis in two test sites in Portugal and Italy. In case study one, innovative multiplatform data classification was performed with the correlation between Sentinel-2 RBR (relativized burn ratio) fire severity classes and the scene hyperspectral signature, performed with a pixel-by-pixel comparison leading to a converging classification. In the adopted methodology, RBR burned area analysis and vegetation recovery was tested for accordance with biophysical vegetation parameters (LAI, fCover, and fAPAR). In case study two, a UAV-sensed NDVI index was adopted for high-resolution mapping data collection. At a large scale, the Sentinel-2 RBR index proved to be efficient for burned area analysis, from both fire severity and vegetation recovery phenomena perspectives. Despite the elapsed time between the event and the acquisition, PRISMA hyperspectral converging classification based on Sentinel-2 was able to detect and discriminate different spectral signatures corresponding to different fire severity classes. At a slope scale, the UAV platform proved to be an effective tool for mapping and characterizing the burned area, giving clear advantage with respect to filed GPS mapping. Results highlighted that UAV platforms, if equipped with a hyperspectral sensor and used in a synergistic approach with PRISMA, would create a useful tool for satellite acquired data scene classification, allowing for the acquisition of a ground truth.

The impact of large-scale reclamation on hydro-dynamic environment–A case study of Xinghua Bay

2015 ◽  
Vol 15 (4) ◽  
pp. 583-592 ◽  
Author(s):  
Jing Yu ◽  
Xianwen Bao ◽  
Yang Ding ◽  
Wei Zhang ◽  
Lingling Zhou
Keyword(s):  
Large Scale ◽  
Dynamic Environment ◽  
The Impact

Overcoming the Challenges of Experimental Research: Lessons From a Criminal Justice Case Study Involving TASER Exposure

2018 ◽  
Vol 42 (3) ◽  
pp. 358-385 ◽  
Author(s):  
Natalie Todak ◽  
Michael D. White ◽  
Lisa M. Dario ◽  
Andrea R. Borrego
Keyword(s):  
Criminal Justice ◽  
Large Scale ◽  
Human Subjects ◽  
Controlled Trial ◽  
Human Subjects Research ◽  
Case Study Approach ◽  
Study Approach ◽  
Randomized Controlled ◽  
The Impact

Objective: To provide guidance to criminologists for conducting experiments in light of two common discouraging factors: the belief that they are overly time-consuming and the belief that they can compromise the ethical principles of human subjects’ research. Method: A case study approach is used, based on a large-scale randomized controlled trial experiment in which we exposed participants to a 5-s TASER shock, to describe how the authors overcame ethical, methodological, and logistical difficulties. Results: We derive four pieces of advice from our experiences carrying out this experimental trial: (1) know your limitations, (2) employ pilot testing, (3) remain flexible and patient, and (4) “hold the line” to maintain the integrity of the research and the safety of human subjects. Conclusions: Criminologists have an obligation to provide the best possible evidence regarding the impact and consequences of criminal justice practices and programs. Experiments, considered by many to be the gold standard of empirical research methodologies, should be used whenever possible in order to fulfill this obligation.

Toward a Model of Brand Creation for International Large-Scale Sporting Events: The Impact of Leadership, Context, and Nature of the Event

2008 ◽  
Vol 22 (5) ◽  
pp. 526-549 ◽  
Author(s):  
Milena M. Parent ◽  
Benoit Séguin
Keyword(s):  
Large Scale ◽  
Sporting Events ◽  
Related Factors ◽  
Initial Event ◽  
Leadership Group ◽  
Leadership Context ◽  
The Impact ◽  
Communication Paths ◽  
Brand Creation

The purpose of this study was to develop a model of brand creation for one-off large-scale sporting events. A case study of the 2005 Montreal FINA (Fédération Internationale de Natation) World Championships highlighted the importance of the leadership group (which must include individuals with political/networking, business/management, and sport/event skills), the context, and the nature of the event for creating the event’s brand. The importance of each aspect is suggested to vary depending on the situation. For example, the lack of an initial event brand will result in the leadership group having the greatest impact on the event’s brand creation process. Findings also highlighted differing communication paths for internal and external stakeholders. Thus, this study contributes to the literature by focusing on brand creation and its related factors instead of the management and outcomes of a brand.

scholarly journals Automatic delineation of debris-covered glaciers using InSAR coherence derived from X-, C- and L-band radar data: a case study of Yazgyl Glacier

2018 ◽  
Vol 64 (247) ◽  
pp. 811-821 ◽  
Author(s):  
STEFAN LIPPL ◽  
SAURABH VIJAY ◽  
MATTHIAS BRAUN
Keyword(s):  
Large Scale ◽  
Window Size ◽  
Radar Data ◽  
Morphological Operations ◽  
L Band ◽  
Surrounding Areas ◽  
Coherence Estimation ◽  
The Impact

ABSTRACTDespite their importance for mass-balance estimates and the progress in techniques based on optical and thermal satellite imagery, the mapping of debris-covered glacier boundaries remains a challenging task. Manual corrections hamper regular updates. In this study, we present an automatic approach to delineate glacier outlines using interferometrically derived synthetic aperture radar (InSAR) coherence, slope and morphological operations. InSAR coherence detects the temporally decorrelated surface (e.g. glacial extent) irrespective of its surface type and separates it from the highly coherent surrounding areas. We tested the impact of different processing settings, for example resolution, coherence window size and topographic phase removal, on the quality of the generated outlines. We found minor influence of the topographic phase, but a combination of strong multi-looking during interferogram generation and additional averaging during coherence estimation strongly deteriorated the coherence at the glacier edges. We analysed the performance of X-, C- and L- band radar data. The C-band Sentinel-1 data outlined the glacier boundary with the least misclassifications and a type II error of 0.47% compared with Global Land Ice Measurements from Space inventory data. Our study shows the potential of the Sentinel-1 mission together with our automatic processing chain to provide regular updates for land-terminating glaciers on a large scale.

Numerical Modelling of a District Scale Groundwater Heat Pump Operation: Case Study from Colchester, UK

2021 ◽  
Author(s):  
Taha Sezer ◽  
Abubakar Kawuwa Sani ◽  
Rao Martand Singh ◽  
David P. Boon
Keyword(s):  
Large Scale ◽  
District Level ◽  
Thermal Plume ◽  
Injection Wells ◽  
Term Operation ◽  
Heating And Cooling ◽  
Groundwater Heat Pump ◽  
The Impact

<p>Groundwater heat pumps (GWHP) are an environmentally friendly and highly efficient low carbon heating technology that can benefit from low-temperature groundwater sources lying in the shallow depths to provide heating and cooling to buildings. However, the utilisation of groundwater for heating and cooling, especially in large scale (district level), can create a thermal plume around injection wells. If a plume reaches the production well this may result in a decrease in the system performance or even failure in the long-term operation. This research aims to investigate the impact of GWHP usage in district-level heating by using a numerical approach and considering a GWHP system being constructed in Colchester, UK as a case study, which will be the largest GWHP system in the UK. Transient 3D simulations have been performed pre-construction to investigate the long-term effect of injecting water at 5°C, into a chalk bedrock aquifer. Modelling suggests a thermal plume develops but does not reach the production wells after 10 years of operation. The model result can be attributed to the low hydraulic gradient, assumed lack of interconnecting fractures, and large (>500m) spacing between the production and injection wells. Model validation may be possible after a period operational monitoring.</p>

scholarly journals Water Preservation and Conservation above Coal Mines Using an Innovative Approach: A Case Study

Energies ◽  
2020 ◽  
Vol 13 (11) ◽  
pp. 2818
Author(s):  
Yujun Xu ◽  
Liqiang Ma ◽  
Yihe Yu
Keyword(s):  
Coal Mining ◽  
Water Conservation ◽  
Large Scale ◽  
Influencing Factor ◽  
Mining Area ◽  
Mining Operations ◽  
Narrow Strip ◽  
Geological Conditions ◽  
The Impact

To better protect the ecological environment during large scale underground coal mining operations in the northwest of China, the authors have proposed a water-conservation coal mining (WCCM) method. This case study demonstrated the successful application of WCCM in the Yu-Shen mining area. Firstly, by using the analytic hierarchy process (AHP), the influencing factors of WCCM were identified and the identification model with a multilevel structure was developed, to determine the weight of each influencing factor. Based on this, the five maps: overburden thickness contour, stratigraphic structure map, water-rich zoning map of aquifers, aquiclude thickness contour and coal seam thickness contour, were analyzed and determined. This formed the basis for studying WCCM in the mining area. Using the geological conditions of the Yu-Shen mining area, the features of caved zone, water conductive fractured zone (WCFZ) and protective zone were studied. The equations for calculating the height of the “three zones” were proposed. Considering the hydrogeological condition of Yu-Shen mining area, the criteria were put forward to evaluate the impact of coal mining on groundwater, which were then used to determine the distribution of different impact levels. Using strata control theory, the mechanism and applicability of WCCM methods, including height-restricted mining, (partial) backfill mining and narrow strip mining, together with the applicable zone of these methods, were analyzed and identified. Under the guidance of “two zoning” (zoning based on coal mining’s impact level on groundwater and zoning based on applicability of WCCM methods), the WCCM practice was carried out in Yu-Shen mining area. The research findings will provide theoretical and practical instruction for the WCCM in the northwest mining area of China, which is important to reduce the impact of mining on surface and groundwater.

scholarly journals Bilevel Traffic Evacuation Model and Algorithm Design for Large-Scale Activities

2017 ◽  
Vol 2017 ◽  
pp. 1-13 ◽  
Author(s):  
Danwen Bao ◽  
Jiayu Gu ◽  
Junhua Jia
Keyword(s):  
Large Scale ◽  
Algorithm Design ◽  
Arrival Rate ◽  
Planning Model ◽  
Objective Functions ◽  
Swarm Optimization ◽  
Evacuation Time ◽  
Classic Model ◽  
The Road

This paper establishes a bilevel planning model with one master and multiple slaves to solve traffic evacuation problems. The minimum evacuation network saturation and shortest evacuation time are used as the objective functions for the upper- and lower-level models, respectively. The optimizing conditions of this model are also analyzed. An improved particle swarm optimization (PSO) method is proposed by introducing an electromagnetism-like mechanism to solve the bilevel model and enhance its convergence efficiency. A case study is carried out using the Nanjing Olympic Sports Center. The results indicate that, for large-scale activities, the average evacuation time of the classic model is shorter but the road saturation distribution is more uneven. Thus, the overall evacuation efficiency of the network is not high. For induced emergencies, the evacuation time of the bilevel planning model is shortened. When the audience arrival rate is increased from 50% to 100%, the evacuation time is shortened from 22% to 35%, indicating that the optimization effect of the bilevel planning model is more effective compared to the classic model. Therefore, the model and algorithm presented in this paper can provide a theoretical basis for the traffic-induced evacuation decision making of large-scale activities.

Objective Reduction Using Axiomatic Design and Product-Related Dependencies: A Layout Synthesis of an Autonomous Greenhouse Case Study

2020 ◽  
Author(s):  
Yann-Seing Law-Kam Cio ◽  
Yuanchao Ma ◽  
Aurelian Vadean ◽  
Giovanni Beltrame ◽  
Sofiane Achiche
Keyword(s):  
Optimization Problem ◽  
Real Life ◽  
Axiomatic Design ◽  
Objective Functions ◽  
Nsga Ii ◽  
Design Problems ◽  
Objective Reduction ◽  
Layout Synthesis ◽  
Design Perspective

Abstract Many-objective optimization problem (MaOP) is defined as optimization with more than 3 objective functions. This high number of objectives makes the comparing solutions more challenging. This holds true for design problems which are MaOPs by nature due to the inherent complexity and multifaceted nature of real-life applications. In the last decades, many strategies have attempted to overcome MaOPs such as removing objectives based on their impact on the optimization. However, from a design perspective, removing objectives could lead to an under optimal, unfeasible or unreliable design. Consequently, objective aggregation seems to be a better approach since objectives can be grouped based on design features controlled by the designers. The proposed methodology uses Axiomatic Design to decompose a system into subsystems or components, and Product-Related Dependencies Management to identify the dependencies between components and formulate the objectives. Then, these objectives are aggregated based on the subsystems found with the Axiomatic Design. The methodology, applied to the layout synthesis of an autonomous greenhouse, can trim down the number of objectives from 15 to 5. Then, using a modified non-dominated sorting genetic algorithm-II (NSGA-II) combined with the objective aggregation, we were able to increase the number of “good” concepts found from 9 to 33 out of a total of 50 obtained designs.

scholarly journals Noise assessment of the small-scale wind farm

2019 ◽  
Vol 112 ◽  
pp. 02011
Author(s):  
Cristian-Gabriel Alionte ◽  
Daniel-Constantin Comeaga
Keyword(s):  
Power Systems ◽  
Large Scale ◽  
Wind Farm ◽  
Wind Farms ◽  
Small Scale ◽  
Large Power ◽  
Small Power ◽  
Noise Assessment ◽  
The Impact

The importance of renewable energy and especially of eolian systems is growing. For this reason, we propose the investigation of an important pollutant - the noise, which has become so important that European Commission and European Parliament introduced Directive 2002/49/CE relating to the assessment and management of environmental noise. So far, priority has been given to very large-scale systems connected to national energy systems, wind farms whose highly variable output power could be regulated by large power systems. Nowadays, with the development of small storage capacities, it is feasible to install small power wind turbines in cities of up to 10,000 inhabitants too. As a case study, we propose a simulation for a rural locality where individual wind units could be used. This specific case study is interesting because it provides a new perspective of the impact of noise on the quality of life when the use of this type of system is implemented on a large scale. This option, of distributed and small power wind turbine, can be implemented in the future as an alternative or an adding to the common systems.

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