11 research outputs found
Introducing algorithm portfolios to a class of vehicle routing and scheduling problem
The paper presents a comprehensive foundation and implementation of Algorithm Portfolios to solve Theater Distribution Vehicle Routing and Scheduling Problems (TDVRSP). In order to evaluate the performance of proposed approach, it has been applied to varying dimensions of theater distribution problem. In particular, eight random search metaheuristics embedded in four processors, packed to form different portfolios. Four basic algorithms- Genetic Algorithm (GA), Simulated Annealing (SA), Tabu Search (TS) and Artificial Immune System (AIS), as well as their group theoretic counterparts have been utilized. The proposed approach also takes care of platform dependence and helps evolving a robust solution pack. The portfolio concept is shown to be computationally advantageous and qualitatively competitive over the benchmark set of problems. The paper does not only provide modeling to TDVRSP, but also aids in developing a generic solution framework for other problems of its kind
Improved and generalized learning strategies for dynamically fast and statistically robust evolutionary algorithms
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Sustainable green infrastructure and operations planning for plug-in hybrid vehicles (PHEVs) : a Tabu Search approach
textIncreasing debates over a gasoline independent future and the reduction of greenhouse gas (GHG) emissions has led to a surge in plug-in hybrid electric vehicles (PHEVs) being developed around the world. Due to the limited all-electric range of PHEVs, a daytime PHEV charging infrastructure will be required for most PHEVsâ daily usage. This dissertation, for the first time, presents a mixed integer mathematical programming model to solve the PHEV charging infrastructure planning (PCIP) problem. Our case study, based on the Oak Ridge National Laboratory (ORNL) campus, produced encouraging results, indicates the viability of the modeling approach and substantiates the importance of considering both employee convenience and appropriate grid connections in the PCIP problem. Unfortunately, the classical optimization methods do not scale up well to larger practical problems. In order to effectively and efficiently attack larger PCIP problems, we develop a new MASTS based TS algorithm, PCIP-TS to solve the PCIP. The results from computational experiments for the ORNL campus problem establish the dominant supremacy of the PCIP-TS method both in terms of solution quality and computational time. Additional experiments with simulated data representative of a problem that might be faced by a small city show that PCIP-TS outperforms CPLEX based optimization.
Once the charging infrastructure is in place, the immediate problem is to judiciously manage this system on a daily basis. This thesis formally develops a mixed integer linear program to solve the daily the energy management problem (DEM) faced by an organization and presented results of a case study performed for ORNL campus. The results from our case study, based on the Oak Ridge National Laboratory (ORNL) campus, are encouraging and substantiate the importance of controlled PHEV fleet charging and realizing V2G capabilities as opposed to uncontrolled charging methods. Although optimal solutions are obtained, the solver requires practically unacceptable computational times for larger problems. Hence, we develop a new MASTS based TS algorithm, DEM-TS, for the DEM models. Results for ORNL campus data set prove the dominant computational efficiency of the DEM-TS. For the simulated extended sized problems that resemble the complexity of a problem faced by a small city, the results prove that DEM-T not only achieves optimality, but also produces sets of multiple alternate optimal solutions. These could be very helpful in practical settings when alternate solutions are necessary because some solutions may not be deployable due to unforeseen circumstances.Mechanical Engineerin
Improved and generalized learning strategies for dynamically fast and statistically robust evolutionary algorithms
This paper characterizes general optimization problems into four categories based on the solution representation schemes, as they have been the key to the design of various evolutionary algorithms (EAs). Four EAs have been designed for different formulations with the aim of utilizing similar and generalized strategies for all of them. Several modifications to the existing EAs have been proposed and studied. First, a new tradeoff function-based mutation has been proposed that takes advantages of Cauchy, Gaussian, random as well as chaotic mutations. In addition, a generalized learning rule has also been proposed to ensure more thorough and explorative search. A theoretical analysis has been performed to establish the convergence of the learning rule. A theoretical study has also been performed in order to investigate the various aspects of the search strategy employed by the new tradeoff-based mutations. A more logical parameter tuning has been done by introducing the concept of orthogonal arrays in the EA experimentation. The use of noise-based tuning ensures the robust parameter tuning that enables the EAs to perform remarkably well in the further experimentations. The performance of the proposed EAs has been analyzed for different problems of varying complexities. The results prove the supremacy of the proposed EAs over other well-established strategies given in the literature
Design of computer network topologies : a vroom inspired psychoclonal algorithm
In the prevailing era of network and communication technology, the problem pertaining to the determination of the most economic way to interconnect nodes while satisfying some reliability and quality of service constraints has been agnized as one of the most intricate and challenging problem for the modern day researchers and practitioners belonging to Communication and Networking community. Motivated by the improved performance of the concepts like proliferation, affinity maturation, receptor editing, etc., over the more prevalent generalized crossover and mutation; and by the application and effectiveness of Maslowâs need hierarchy in combinatorial optimization as well the more logical motivational concepts provided by Vroomâs valence expectancy theory, authors have proposed and investigated their applications to the topological design of distributed packet switched networks. The extensive computations over the problems of varying complexities and dimensions prove the superiority of the proposed methodology. It has been observed that the proposed Vroom Inspired Psychoclonal Algorithm (VIPA) outperforms the traditional well established random search algorithms (i.e. Genetic Algorithm, Simulated Annealing and Artificial Immune Systems) in the context of underlying problem; the performance being significantly improved as the problem complexity increases
(Groundwater Stories: Villagers Share Their Voices)
Indiaâs groundwater story is uniquely scripted by millions of farmers who independently operate and manage dug wells and tubewells throughout the country leading to increasing level of groundwater anarchy. Access to cheap pumps, subsidised electricity, changing crop patterns and increasing population have increased the tensions between groundwater supply and use that typify uncoordinated pumping of groundwater. Maintaining groundwater dependent rural livelihoods without further reductions in already depleted hard rock aquifers is a critical dilemma faced by the government and farming communities in rural India. Using the Dharta and Meghraj watersheds as examples to understand groundwater challenges, the focus of this Photovoice narrative, we share here the groundwater stories of ordinary people in this book. Literally viewed through the lens of individuals, the everyday stories told by villagers in this book introduce emotional and profound glimpses into the nexus of groundwater and livelihoods in rural India and the values held by villagers and their families. The photo essays also introduce humanness into the groundwater story in India and how it connects and contradicts with contemporary economics, politics, hydrology and agronomy in groundwater deliberations. The narratives presented are not simply opportunistic and arbitrary caricatures of Indian farming communities; these are carefully and systematically crafted photo-essays corroborated and endorsed by the individual story tellers. The systematic interaction with the individual story tellers increases the confidence that these are accurate reflections of the groundwater dilemma facing farming communities, and their ideas about the situation improvement. We hope this book will help you visualise how groundwater connects with villagers and influences their daily lives and understanding the complexity of managing and sustaining this invisible resource
Groundwater Stories: Villagers Share Their Voices
This book, Groundwater Stories â Villagers Share Their Voices, emerged from an ACIAR-funded research project titled Managing aquifer recharge and sustaining groundwater use through village-level intervention (AMRVI). The project was implemented in the Meghraj watershed in Aravalli district of Gujarat and the Dharta watershed in Udaipur district of Rajasthan, in India. The technique used to develop the stories in this book is called PhotoVoice. This powerful technique enables ordinary peopleâusually with limited power due to poverty, low literacy levels, ethnicity, gender, culture or other circumstances to capture and share aspects of their environment, worldviews and experiences through photography. Farmers, school children and others in the study villages of the MARVI project shared their photos, through this book, to bring the realities of everyday water issues and challenges to the attention of the community and policy makers. The photographs captured what surface and ground waters meant to the villagers, in the present and future, what they valued most about water, and how they saw their own responsibilities for village water security. The book is an example of how grassroots activities, such as storytelling, can be used to develop engagement, ownership and vision for local problems and solutions in rural development projects. The process of producing this book has indirectly helped villagers in the MARVI project to explore the problem and identify possible solutions for their groundwater situation
Managing aquifer recharge and sustaining groundwater use : developing a capacity building program for creating local groundwater champions
Participatory groundwater management is increasingly being recognised for its ability to address the challenges of equity, efficiency and sustainability. It can particularly help with effective engagement at the grassroots level for monitoring, recharging and managing the groundwater as a common pool resource. The main aim of this article is to discuss the training and management process used and the lessons learnt from a participatory groundwater management project, titled Managing Aquifer Recharge and Sustainable Groundwater Use through Village-level Intervention (MARVI). In this project, researchers, rural development facilitators and local villagers worked together to initiate participatory groundwater monitoring in 11 villages from the Dharta and Meghraj watersheds in Rajasthan and Gujarat, India. The study involved educating villagers through an intensive program of capacity building, wherein the villagers who participated in the program were called Bhujal Jaankars (BJs), a Hindi word meaning âgroundwater informedâ. The BJs were trained in their local settings through relevant theory and practical exercises, so that they could perform a geo-hydrological evaluation of their area, monitor groundwater and share their findings and experiences with their village community. The study has highlighted that with a well-designed program of capacity building and on-going support through training and nurturing, BJs can play an important role in monitoring watertable depth and other data for estimating groundwater recharge, leading to a sharing of the groundwater information with the local village community to influence the sustainable use of groundwater. Overall they can act as local champions for groundwater futures. Further, this study has demonstrated that BJ capacity building can help to provide a scientific basis for village level groundwater dialogue and assist village communities and other stakeholders to improve their decision making regarding groundwater use, crop selection, agronomy, recharge strategies and other aspects of sustainable groundwater management. Although the BJ program has been successful and BJs can act as a valuable interface between local communities and other stakeholders managed aquifer recharge activities, there still exists some challenges to the BJ programme, such as the need for mechanisms and funding sources that will sustain the BJs over the longer term; wider acceptance of BJs among scientific communities and policy makers; and the acceptance of the role and involvements of BJs in natural resources management programs of the State and Central governments in India
The role of transdisciplinary approach and community participation in village scale groundwater management : insights from Gujarat and Rajasthan, India
Sustainable use of groundwater is becoming critical in India and requires
effective participation from local communities along with technical, social, economic, policy and political inputs. Access to groundwater for farming communities is also an emotional and complex issue as their livelihood and survival depends on it. In this article, we report on transdisciplinary approaches to understanding the issues, challenges and options for improving sustainability of groundwater use in States of Gujarat and Rajasthan, India. In this project, called Managed Aquifer Recharge through Village level Intervention
(MARVI), the research is focused on developing a suitable participatory approach and methodology with associated tools that will assist in improving supply and demand management of groundwater. The study was conducted in the Meghraj watershed in Aravalli district, Gujarat, and the Dharta watershed in Udaipur district, Rajasthan, India. The study involved the collection of hydrologic, agronomic and socio-economic data and engagement of local village and school communities through their role in groundwater monitoring, field trials, photovoice activities and education campaigns. The study revealed
that availability of relevant and reliable data related to the various aspects of groundwater and developing trust and support between local communities, NGOs and government agencies are the key to moving towards a dialogue to decide on what to do to achieve sustainable use of groundwater. The analysis of long-term water table data indicated considerable fluctuation in groundwater levels from year to year or a net lowering of the water table, but the levels tend to recover during wet years. This provides hope that by improving management of recharge structures and groundwater pumping, we can assist in stabilizing the local water table. Our interventions through Bhujal Jankaars (BJs), (a Hindi
word meaning âgroundwater informedâ volunteers), schools, photovoice workshops and newsletters have resulted in dialogue within the communities about the seriousness of the groundwater issue and ways to explore options for situation improvement. The BJs are now trained to understand how local recharge and discharge patterns are influenced by local rainfall patterns and pumping patterns and they are now becoming local champions of groundwater and an important link between farmers and project team. This study has further strengthened the belief that traditional research approaches to improve the
groundwater situation are unlikely to be suitable for complex groundwater issues in the study areas. The experience from the study indicates that a transdisciplinary approach is likely to be more effective in enabling farmers, other village community members and NGOs to work together with researchers and government agencies to understand the groundwater situation and design interventions that are holistic and have wider ownership. Also, such an approach is expected to deliver longer-term sustainability of groundwater at
a regional level