Domain value mutation and other techniques for constraint satisfaction problems

The term Constraint Satisfaction Problem (CSP) refers to a class of NP-complete problems, a collection of difficult problems for which no fast solution is known. The standard definition of a CSP involves variables, values, and constraints: each variable must be assigned a value from a designated group of possible values (also known as the variable’s domain), while a constraint on a set of variables indicates permissible combinations of values for these variables. Given a CSP, an important objective is to query whether it has a solution — an assignment of each variable to a value such that all constraints are satisfied. Solving a CSP usually requires chronological backtracking search that interleaves variable assignments with various kinds of inferences in order to reduce the search space. This dissertation comprises two parts. The first part deals with a modification of the classical CSP model that allows a value to be broken up and multiple values to be combined. The second part deals with generalized arc consistency algorithms. Both parts share a common theme in that extensional constraints --‐ the most basic expression possible for constraints --- play the central role. Despite being an important class, extensional constraints have received much less attention recently as most efforts have been channelled toward identifying new types of specialized constraints and coming up with corresponding algorithms. Regardless, improvements to algorithms for extensional constraints are more fundamental. This dissertation will attempt to improve existing techniques and algorithms for extensional constraints by examining them critically from the bottom up and approaching them from a novel direction

Development of a Systems Engineering Model of the Chemical Separations Process: Final Report

The whole chemical separation process is complex to the point that definitely requires certain level of systematic coordination. To perform smoothly and meet the target extraction rates among those processes, this research proposed a general-purpose systems engineering model. A general purposed systems engineering model, Transmutation Research Program System Engineering Model Project (TRPSEMPro), was developed based on the above design concept. The system model includes four main parts: System Manager, Model Integration, Study Plan, and Solution Viewer. TRPSEMPro can apply not only to chemical separation process, but also a general system model. Software engineering and Object Oriented Analysis and Design (OOA&D) play a critical role during our software development. Through the application of OOA&D, the user can define objects and concepts from our problem domain that is quantitatively described by Unified Modeling Language (UML). The logical software objects were created from the previous definition. Meanwhile, different design patterns were also applied during the detailed design phase. Finally, those designed components were implemented by using MicrosoftTM.Net, the most up-to-date object-oriented programming language framework from Microsoft. Currently, only the UREX process module is available and ready to be implemented. Since extraction modules can be developed from various agencies with different development concepts and programming conventions, an intermediate bridge or interpreter is generally required. The system connects the only available process, UREX and with the TRPSEMPro system model from the AMUSESimulator interface. The AMUSESimulator communicates with the calculation engine AMUSE macros designed for the UREX process. A user-friendly GUI in AMUSESimulator allows the user to efficiently define the UREX process – flowsheet, input streams, sections, and stages

Soft Computing

Soft computing is used where a complex problem is not adequately specified for the use of conventional math and computer techniques. Soft computing has numerous real-world applications in domestic, commercial and industrial situations. This book elaborates on the most recent applications in various fields of engineering

Adaptive scaling of evolvable systems

Neo-Darwinian evolution is an established natural inspiration for computational optimisation with a diverse range of forms. A particular feature of models such as Genetic Algorithms (GA) [18, 12] is the incremental combination of partial solutions distributed within a population of solutions. This mechanism in principle allows certain problems to be solved which would not be amenable to a simple local search. Such problems require these partial solutions, generally known as building-blocks, to be handled without disruption. The traditional means for this is a combination of a suitable chromosome ordering with a sympathetic recombination operator. More advanced algorithms attempt to adapt to accommodate these dependencies during the search. The recent approach of Estimation of Distribution Algorithms (EDA) aims to directly infer a probabilistic model of a promising population distribution from a sample of fitter solutions [23]. This model is then sampled to generate a new solution set. A symbiotic view of evolution is behind the recent development of the Compositional Search Evolutionary Algorithms (CSEA) [49, 19, 8] which build up an incremental model of variable dependencies conditional on a series of tests. Building-blocks are retained as explicit genetic structures and conditionally joined to form higher-order structures. These have been shown to be effective on special classes of hierarchical problems but are unproven on less tightly-structured problems. We propose that there exists a simple yet powerful combination of the above approaches: the persistent, adapting dependency model of a compositional pool with the expressive and compact variable weighting of probabilistic models. We review and deconstruct some of the key methods above for the purpose of determining their individual drawbacks and their common principles. By this reasoned approach we aim to arrive at a unifying framework that can adaptively scale to span a range of problem structure classes. This is implemented in a novel algorithm called the Transitional Evolutionary Algorithm (TEA). This is empirically validated in an incremental manner, verifying the various facets of the TEA and comparing it with related algorithms for an increasingly structured series of benchmark problems. This prompts some refinements to result in a simple and general algorithm that is nevertheless competitive with state-of-the-art methods

Soft Computing

Soft computing is used where a complex problem is not adequately specified for the use of conventional math and computer techniques. Soft computing has numerous real-world applications in domestic, commercial and industrial situations. This book elaborates on the most recent applications in various fields of engineering

Development of a Systems Engineering Model for Chemical Separation Process

This thesis is concerned with the efforts to develop a general-purpose systems engineering model software TRPSEMPro1 that can be used to improve productivity in the design process. Different features of TRPSEMPro will be presented in this thesis. First, Systems Engineering technology is presented, followed by the exposition of different numerical optimization technologies and DOE (Design of Experiments) study technologies. Second, the detailed software process, Object-Oriented Analysis and Design (OOA&D) for the TRPSEMPro is presented. All the design data models are expressed by using Unified Modeling Language (UML). AMUSESimulator is another software package which has been designed and implemented in order to serve as a bridge between AMUSE Macro, developed by ANL, and systems engineering model, TRPSEMPro. The design process for AMUSESimulator is elaborated in this thesis. The topics in this thesis also include SQL Server Database, XML, DOE techniques and optimization techniques. Several study cases which apply the developed systems engineering model to solve typical design problems are demonstrated

Novel methods for generalizing nuclear fuel cycle design, and fuel burnup modeling

The large number of reactor designs and concepts in existence open up a vast array of nuclear fuel cycle strategies. u. These different reactor types require unique supporting systems from raw material extraction and handling to waste management. Any system designed to model nuclear energy should therefore have methods that are capability of representing a large number of unique fuel cycles. This work examines a user interface designed to generalize the design of nuclear fuel cycles. This software, known as CycIC, allows users to interact graphically with a fuel cycle simulator (Cyclus). In this work, the capabilities of CycIC were improved through two rounds of rigorous user experience testing. These tests were used as a basis for implementing improvements to the software. Two views inside the software were improved to allow for users to interact with the software more intuitively, and features that provide help to the users were added to improve understanding of fuel cycles and Cyclus. Additionally, this work expands the capabilities of a reactor modeling software (known as Bright-lite) which uses the fluence based neutron balance approach to determine burnup, criticality, and transmutation matrixes for nuclear reactors to augment its modeling of the broadest range of fuel cycle strategies. Specifically, a multi-dimensional interpolation method was implemented to enable reactors to be characterized by sets of cross section libraries which potentially depend on a large number of reactor characteristics. The accuracy of this interpolation method is demonstrated for a number of parameters for light water reactors, and techniques for using this interpolation method to automatically generate reactor libraries for Bright-lite are demonstrated. This research also generalizes the ability of the Bright-lite to blend multiple streams of nuclear fuel while still maintaining constraints. This system is demonstrated for continuous recycle nuclear fuel cycles utilizing light water and fast spectrum reactors. The results show that Bright-lite is capable of blending fuel to reach several targets using up to three different input streams.Mechanical Engineerin

Radioactive Waste

The safe management of nuclear and radioactive wastes is a subject that has recently received considerable recognition due to the huge volume of accumulative wastes and the increased public awareness of the hazards of these wastes. This book aims to cover the practice and research efforts that are currently conducted to deal with the technical difficulties in different radioactive waste management activities and to introduce to the non-technical factors that can affect the management practice. The collective contribution of esteem international experts has covered the science and technology of different management activities. The authors have introduced to the management system, illustrate how old management practices and radioactive accident can affect the environment and summarize the knowledge gained from current management practice and results of research efforts for using some innovative technologies in both pre-disposal and disposal activities

The Role of Creativity in Entrepreneurship

This paper evaluates the contribution of creativity to entrepreneurship theory and practice in terms of building an holistic and transdisciplinary understanding of its impact. Acknowledgement is made of the subjectivist theory of entrepreneurship which embraces randomness, uncertainty and ambiguity but these factors should then be embedded in wider business and social contexts. The analysis is synthesised into a number of themes, from consideration of its definition, its link with personality and cognitive style, creativity as a process and the use of biography in uncovering data on creative entrepreneurial behaviour. Other relevant areas of discussion include creativity’s link with motivation, actualisation and innovation, as well as the interrogation of entrepreneurial artists as owner/managers. These factors are embedded in a critical evaluation of how creativity contributes to successful entrepreneurship practice. Modelling, measuring and testing entrepreneurial creativity are also considered and the paper includes detailed consideration of several models of creativity in entrepreneurship. Recommendations for future theory and practice are also made