281 research outputs found
Methodology for technology evaluation under uncertainty and its application in advanced coal gasification processes
Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Chemical Engineering, 2011.Cataloged from PDF version of thesis.Includes bibliographical references (p. 273-287).Integrated gasification combined cycle (IGCC) technology has attracted interest as a cleaner alternative to conventional coal-fired power generation processes. While a number of pilot projects have been launched to experimentally test IGCC technologies, mathematical simulation remains a central part of the ongoing research efforts. A major challenge in modeling an IGCC power plant is the lack of real experience and reliable data. It is critical to properly understand the state of knowledge and evaluate the impact of uncertainty in every phase of the R&D process. A rigorous investigation of the effect of uncertainty on IGCC system requires accurate quantification of input uncertainty and efficient propagation of uncertainty through system models. This thesis proposes several uncertainty quantification methods which expand the sources of information that can be used for parameter estimation. Key features of these methods include the use of entropy maximization to translate subjective opinions to probability distribution functions, and a more flexible probability model that easily captures anomaly associated with small sample data. In addition, Bayesian estimation is extended to dynamic models. Aided by a computationally efficient algorithm, termed sequential Monte Carlo method, the Bayesian approach is shown to be an effective way to estimate time-variant parameters. Uncertainty propagation is performed using the deterministic equivalent modeling method (DEMM) which is based on polynomial chaos representation of random variables and probabilistic collocation algorithm. One major issue often overlooked in the analysis of IGCC models is to represent correlation in the input parameters. This thesis proposes the use of principal component analysis (PCA) to represent correlated random variables. The resulting formulation is the same as the truncated Karhunen-Lodve expansions. Explicit incorporation of correlation not only improves accuracy of the approximation but also reduces the overall computational time. A comprehensive study of the MIT-BP IGCC model is carried out to determine uncertainties of the key measures of performance and cost, including energy output, thermal efficiency, CO 2 emission, plant capital cost, and cost of electricity. Whenever possible, the probability distributions of input parameters are estimated based on realistic data. Experts' judgments are solicited if data acquisition is infeasible. Uncertainty analysis is conducted in a three-step approach. First, technology-related input parameters are taken into account to determine uncertainties of plant performance. Second, cost uncertainties are determined with only economic inputs in order to identify important economic parameters. Finally, the plant model is integrated with cost model and they are evaluated with the key technical and economic inputs identified in the previous steps. Our study indicates the property of coal feed has a substantial impact on the energy production of the IGCC plant, and subsequently on the cost of electricity. Immature technologies such as gasification and gas turbine have important bearing on model performance hence need to be addressed in future research.by Bo Gong.Ph.D
Green Technologies for Production Processes
This book focuses on original research works about Green Technologies for Production Processes, including discrete production processes and process production processes, from various aspects that tackle product, process, and system issues in production. The aim is to report the state-of-the-art on relevant research topics and highlight the barriers, challenges, and opportunities we are facing. This book includes 22 research papers and involves energy-saving and waste reduction in production processes, design and manufacturing of green products, low carbon manufacturing and remanufacturing, management and policy for sustainable production, technologies of mitigating CO2 emissions, and other green technologies
Risk Management in Environment, Production and Economy
The term "risk" is very often associated with negative meanings. However, in most cases, many opportunities can present themselves to deal with the events and to develop new solutions which can convert a possible danger to an unforeseen, positive event. This book is a structured collection of papers dealing with the subject and stressing the importance of a relevant issue such as risk management. The aim is to present the problem in various fields of application of risk management theories, highlighting the approaches which can be found in literature
Analysis of Decision Support Systems of Industrial Relevance: Application Potential of Fuzzy and Grey Set Theories
The present work articulates few case empirical studies on decision making in industrial
context. Development of variety of Decision Support System (DSS) under uncertainty and
vague information is attempted herein. The study emphases on five important decision making
domains where effective decision making may surely enhance overall performance of the
organization. The focused territories of this work are i) robot selection, ii) g-resilient supplier
selection, iii) third party logistics (3PL) service provider selection, iv) assessment of supply
chain’s g-resilient index and v) risk assessment in e-commerce exercises.
Firstly, decision support systems in relation to robot selection are conceptualized through
adaptation to fuzzy set theory in integration with TODIM and PROMETHEE approach, Grey
set theory is also found useful in this regard; and is combined with TODIM approach to
identify the best robot alternative. In this work, an attempt is also made to tackle subjective
(qualitative) and objective (quantitative) evaluation information simultaneously, towards
effective decision making.
Supplier selection is a key strategic concern for the large-scale organizations. In view of this, a
novel decision support framework is proposed to address g-resilient (green and resilient)
supplier selection issues. Green capability of suppliers’ ensures the pollution free operation;
while, resiliency deals with unexpected system disruptions. A comparative analysis of the
results is also carried out by applying well-known decision making approaches like Fuzzy-
TOPSIS and Fuzzy-VIKOR.
In relation to 3PL service provider selection, this dissertation proposes a novel ‘Dominance-
Based’ model in combination with grey set theory to deal with 3PL provider selection,
considering linguistic preferences of the Decision-Makers (DMs). An empirical case study is
articulated to demonstrate application potential of the proposed model. The results, obtained
thereof, have been compared to that of grey-TOPSIS approach.
Another part of this dissertation is to provide an integrated framework in order to assess gresilient
(ecosilient) performance of the supply chain of a case automotive company. The
overall g-resilient supply chain performance is determined by computing a unique ecosilient
(g-resilient) index. The concepts of Fuzzy Performance Importance Index (FPII) along with
Degree of Similarity (DOS) (obtained from fuzzy set theory) are applied to rank different gresilient
criteria in accordance to their current status of performance.
The study is further extended to analyze, and thereby, to mitigate various risk factors (risk
sources) involved in e-commerce exercises. A total forty eight major e-commerce risks are
recognized and evaluated in a decision making perspective by utilizing the knowledge
acquired from the fuzzy set theory. Risk is evaluated as a product of two risk quantifying
parameters viz. (i) Likelihood of occurrence and, (ii) Impact. Aforesaid two risk quantifying
parameters are assessed in a subjective manner (linguistic human judgment), rather than
exploring probabilistic approach of risk analysis. The ‘crisp risk extent’ corresponding to
various risk factors are figured out through the proposed fuzzy risk analysis approach. The risk
factor possessing high ‘crisp risk extent’ score is said be more critical for the current problem
context (toward e-commerce success). Risks are now categorized into different levels of
severity (adverse consequences) (i.e. negligible, minor, marginal, critical and catastrophic).
Amongst forty eight risk sources, top five risk sources which are supposed to adversely affect
the company’s e-commerce performance are recognized through such categorization. The
overall risk extent is determined by aggregating individual risks (under ‘critical’ level of
severity) using Fuzzy Inference System (FIS). Interpretive Structural Modeling (ISM) is then
used to obtain structural relationship amongst aforementioned five risk sources. An
appropriate action requirement plan is also suggested, to control and minimize risks associated
with e-commerce exercises
Sustainable Industrial Engineering along Product-Service Life Cycle/Supply Chain
Sustainable industrial engineering addresses the sustainability issue from economic, environmental, and social points of view. Its application fields are the whole value chain and lifecycle of products/services, from the development to the end-of-life stages. This book aims to address many of the challenges faced by industrial organizations and supply chains to become more sustainable through reinventing their processes and practices, by continuously incorporating sustainability guidelines and practices in their decisions, such as circular economy, collaboration with suppliers and customers, using information technologies and systems, tracking their products’ life-cycle, using optimization methods to reduce resource use, and to apply new management paradigms to help mitigate many of the wastes that exist across organizations and supply chains. This book will be of interest to the fast-growing body of academics studying and researching sustainability, as well as to industry managers involved in sustainability management
Uncertain Multi-Criteria Optimization Problems
Most real-world search and optimization problems naturally involve multiple criteria as objectives. Generally, symmetry, asymmetry, and anti-symmetry are basic characteristics of binary relationships used when modeling optimization problems. Moreover, the notion of symmetry has appeared in many articles about uncertainty theories that are employed in multi-criteria problems. Different solutions may produce trade-offs (conflicting scenarios) among different objectives. A better solution with respect to one objective may compromise other objectives. There are various factors that need to be considered to address the problems in multidisciplinary research, which is critical for the overall sustainability of human development and activity. In this regard, in recent decades, decision-making theory has been the subject of intense research activities due to its wide applications in different areas. The decision-making theory approach has become an important means to provide real-time solutions to uncertainty problems. Theories such as probability theory, fuzzy set theory, type-2 fuzzy set theory, rough set, and uncertainty theory, available in the existing literature, deal with such uncertainties. Nevertheless, the uncertain multi-criteria characteristics in such problems have not yet been explored in depth, and there is much left to be achieved in this direction. Hence, different mathematical models of real-life multi-criteria optimization problems can be developed in various uncertain frameworks with special emphasis on optimization problems
Energy Use Efficiency
Energy is one of the most important factors of production. Its efficient use is crucial for ensuring production and environmental quality. Unlike normal goods with supply management, energy is demand managed. Efficient energy use—or energy efficiency—aims to reduce the amount of energy required to provide products and services. Energy use efficiency can be achieved in situations such as housing, offices, industrial production, transport and agriculture as well as in public lighting and services. The use of energy can be reduced by using technology that is energy saving. This Special Issue is a collection of research on energy use efficiency
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