Estabelecendo um processo de customização livre de retrocessos para famílias de produtos

Orientador: Yuzo IanoTese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia Elétrica e de ComputaçãoResumo: Um conceito chave na área de customização em massa é o de família de produtos. Embora o projeto de uma família de produtos é uma tarefa difícil e desafiadora, derivar os membros da família de produtos para atender os requisitos de clientes individuais pode ser uma tarefa de design rotineira. Neste trabalho, propomos uma abordagem formal para modelar o processo de customização de famílias de produtos, que alcançar este objetivo. De fato, construímos uma teoria para a customização de famílias de produtos. Esta abordagem é baseada em uma estrutura de conhecimento para a representação de famílias de produtos que combina uma estrutura de produto genérica e uma rede de restrições estendida com funções de design. O método para derivar os membros da família de produtos é um processo de instanciação com duas fases. Primeiramente, uma solução para o modelo de rede de restrição consistente com os requisitos do cliente é encontrada. Em seguida, esta solução é utilizada para transformar a estrutura de produto genérica em uma estrutura especifica que corresponde a um membro da família de produtos. Neste trabalho, provamos que, se o modelo de rede de restrição estendida com funções de design satisfaz algumas condições de modelagem, então encontrar soluções se torna um processo livre de retrocessos. Embora existam outros trabalhos na literatura que também afirmam ser livre de retrocessos, um fato notável sobre a nossa abordagem é que conseguimos isso através da introdução de conhecimento sobre a família de produtos, em vez de recorrer ao poder computacional e pré-processamento como naquelas abordagens. Outro aspecto notável da nossa abordagem é que os componentes podem ser projetados como parte do processo de personalização através das funções de design. Isto implica que é possível dispor de um processo de customização eficiente sem comprometer a flexibilidade da família de produtos. Na conclusão deste trabalho, argumentamos que a nossa abordagem pode lidar com problemas de customização que estão fora da área de configuração de produtos. Dois apêndices também são adicionados à tese. Um deles é uma modelagem completa de uma família de produtos Chave de Transferência Automática (ATS) baseado em nossa abordagem. Este exemplo é usado no corpo principal da tese para ilustrar os conceitos que estão sendo introduzidos. A outra é uma implementação computacional do primeiro estágio do processo de customização da família de produtos ATSAbstract: Product family is a key concept is the area of mass customisation. Although the design of a product family is a difficult and challenging task, to derive members of the product family to meet the requirements of individual customers can be a routine design task. In this work, we propose a formal approach to model the customisation of product families that achieves this goal. In fact, we are setting up a theory for the customization of product families. This approach is based on a knowledge framework for the representation of product families, which combines a generic product structure and a constraint network extended with design functions. The method for deriving members of the product family is a two-stage instantiation process. First, a solution to the constraint network model consistent with the customer requirements is found. Next, this solution is used to transform the generic product structure into a specific structure that corresponds to a member of the product family. In this work, we prove that if the constraint network model extended with design functions satisfies a few modelling conditions, then to find solutions become a backtrack-free process. Although there are other works in the literature that also claim to be backtrack-free, a remarkable fact about our approach is that we achieve this by the introduction of knowledge about the product family, instead of resorting to computational power and pre-processing as in those approaches. Another remarkable aspect of our approach is that components can be designed as part of the customisation process using the design functions. This implies that it is possible to have an efficient customisation process without compromising the flexibility of the product family. In the conclusion of this work, we argue that our approach can deal with customisation problems outside the product configuration area. Two appendixes are also added to the thesis. One is a compete modelling of the Automatic Transfer Switch (ATS) product family using our approach. This example is used in the main body of the thesis to illustrate the concepts that are being introduced. The other one is the computational implementation of the first-stage customisation process of the ATS product familyDoutoradoTelecomunicações e TelemáticaDoutor em Engenharia Elétric

Minimizing the sum of flow times with batching and delivery in a supply chain

This thesis was submitted for the degree of Doctor of Philosophy and awarded by Brunel University.The aim of this thesis is to study one of the classical scheduling objectives that is of minimizing the sum of flow times, in the context of a supply chain network. We consider the situation that a supplier schedules a set of jobs for delivery in batches to several manufacturers, who in tum have to schedule and deliver jobs in batches to several customers. The individual problem from the viewpoint of supplier and manufacturers will be considered separately. The decision problem faced by the supplier is that of minimizing the sum of flow time and delivery cost of a set of jobs to be processed on a single machine for delivery in batches to manufacturers. The problem from the viewpoint of manufacturer is similar to the supplier's problem and the only difference is that the scheduling, batching and delivery decisions made by the supplier define a release date for each job, before which the manufacturer cannot start the processing of that job. Also a combined problem in the light of cooperation between the supplier and manufacturer will be considered. The objective of the combined problem is to find the best scheduling, batching, and delivery decisions that benefit the entire system including the supplier and manufacturer. Structural properties of each problem are investigated and used to devise a branch and bound solution scheme. Computational experience shows significant improvements over existing algorithms and also shows that cooperation between a supplier and a manufacturer reduces the total system cost of up to 12.35%, while theoretically the reduction of up to 20% can be achieved for special cases

Factorized Graph Representations for Semi-Supervised Learning from Sparse Data

Node classification is an important problem in graph data management. It is commonly solved by various label propagation methods that work iteratively starting from a few labeled seed nodes. For graphs with arbitrary compatibilities between classes, these methods crucially depend on knowing the compatibility matrix that must be provided by either domain experts or heuristics. Can we instead directly estimate the correct compatibilities from a sparsely labeled graph in a principled and scalable way? We answer this question affirmatively and suggest a method called distant compatibility estimation that works even on extremely sparsely labeled graphs (e.g., 1 in 10,000 nodes is labeled) in a fraction of the time it later takes to label the remaining nodes. Our approach first creates multiple factorized graph representations (with size independent of the graph) and then performs estimation on these smaller graph sketches. We define algebraic amplification as the more general idea of leveraging algebraic properties of an algorithm's update equations to amplify sparse signals. We show that our estimator is by orders of magnitude faster than an alternative approach and that the end-to-end classification accuracy is comparable to using gold standard compatibilities. This makes it a cheap preprocessing step for any existing label propagation method and removes the current dependence on heuristics.Comment: SIGMOD 2020 (Extended version

Pattern matching : a sheaf-theoretic approach

A general theory of pattern matching is presented by adopting an extensional, geometric view of patterns. The extension of the matching relation consists of the occurrences of all possible patterns in a particular target. The geometry of the pattern describes the structure of the pattern and the spatial relationships among parts of the pattern. The extension and the geometry, when combined, produce a structure called a sheaf. Sheaf theory is a well developed branch of mathematics which studies the global consequences of locally defined properties. For pattern matching, an occurrence of a pattern, a global property of the pattern, is obtained by gluing together occurrences of parts of the pattern, which are locally defined properties.A sheaf-theoretic view of pattern rnatching provides a uniforrn treatrnent of pattern matching on any kind of data structure-strings, trees, graphs, hypergraphs, and so on. Such a parametric description is achieved by using the language of category theory, a highly abstract description of commonly occurring structures and relationships in mathematics.A generalized version of the Knuth-Morris-Pratt pattern matching algorithm is derived by gradually converting the extensional description of pattern rnatching as a sheaf into an intensional description. The algorithm results from a synergy of four very general program synthesis/transformation techniques: (1) Divide and conquer: exploit the sheaf condition; assemble a full match by gluing together partial matches; (2) Finite differencing: collect and update partial matches incrementally while traversing the target; (3) Backtracking: instead of saving all partial matches, save just one; when this partial match cannot be extended, fail back to another; (4) Partial evaluation: precompute pattern-based (and therefore constant) computations.The derivation is carried out in a general frarnework using Grothendieck topologies. By appropriately instantiating the underlying data structures and topologies, the sarne scheme results in matching algorithms for patterns with variables and with multiple patterns. Slight variations of the derivation result in Earley's algorithm for context-free parsing, and Waltz filtering, a relaxation algorithm for providing 3-D interpretations to 2-D irnages.Other applications of a geometric view of patterns are briefly considered: rewrites, parallel algorithms, induction and computability

A sheaf-theoretic approach to pattern matching and related problems

AbstractWe present a general theory of pattern matching by adopting an extensional, geometric view of patterns. Representing the geometry of the pattern via a Grothendieck topology, the extension of the matching relation for a constant target and varying pattern forms a sheaf. We derive a generalized version of the Knuth-Morris-Pratt string-matching algorithm by gradually converting this extensional description into an intensional description, i.e., an algorithm. The generality of this approach is illustrated by briefly considering other applications: Earley's algorithm for parsing, Waltz filtering for scene analysis, matching modulo commutativity, and the n-queens problem

Random Testing For Language Design

Property-based random testing can facilitate formal verification, exposing errors early on in the proving process and guiding users towards correct specifications and implementations. However, effective random testing often requires users to write custom generators for well-distributed random data satisfying complex logical predicates, a task which can be tedious and error prone. In this work, I aim to reduce the cost of property-based testing by making such generators easier to write, read and maintain. I present a domain-specific language, called Luck, in which generators are conveniently expressed by decorating predicates with lightweight annotations to control both the distribution of generated values and the amount of constraint solving that happens before each variable is instantiated. I also aim to increase the applicability of testing to formal verification by bringing advanced random testing techniques to the Coq proof assistant. I describe QuickChick, a QuickCheck clone for Coq, and improve it by incorporating ideas explored in the context of Luck to automatically derive provably correct generators for data constrained by inductive relations. Finally, I evaluate both QuickChick and Luck in a variety of complex case studies from programming languages literature, such as information-flow abstract machines and type systems for lambda calculi

Heuristics for Periodic Scheduling

V posledních několika desetiletích se masivně zvýšilo využívání elektronických komunikačních systémů, které ovlivňují všechny oblasti lidské činnosti. Díky nízkým nákladům a vysoké efektivitě mohou být tyto modely široce rozšířené. Masivní využívání takových systémů v různých doménách jako je průmysl, chytrá města (smart cities), atd., volá po vývoji rozvrhovacích metod, které jsou rychlé, přizpůsobivé a spolehlivé. V této práci formalizujeme problém vysoce kritického periodického rozvrhování. Dále navrhujeme aplikaci v Javě, která umožnuje jednoduché testování různých rozvrhovacích metod. Hlavní přínos této práce spočívá v několika heuristikách vhodných pro striktně periodické rozvrhování komunikace a porovnání jejich výkonnosti na vygenerovaných instancích.In the past decades, the usage of electronic communication systems that influence all areas of human activities massively increased. Low cost and high effectiveness allow it to be used widely. The massive usage of such systems in different domains such as industry, smart cities, etc. calls for developing scheduling methods that are fast, adjustable and reliable. In this thesis, we formalize the highly critical periodic scheduling problem and design a Java-based framework that allows easy testing of different scheduling methods. The main contribution of this thesis is several heuristics suitable for strictly periodic network communication and comparison of their performance on generated instances