100 research outputs found

    A Neighborhood Search for Sequence-dependent Setup Time in Flow Shop Fabrics Making of Textile Industry

    Get PDF
    Abstract This paper proposes a neighborhood search to solve scheduling for fabrics making in a textile industry. The production process consists of three production stages from spinning, weaving, and dyeing. All stages have one processor. Setup time between two consecutive jobs with different color is considered. This paper also proposes attribute’s decomposition of a single job to classify available jobs to be processed and to consider setup time between two consecutive jobs. Neighborhood search (NS) algorithm is proposed in which the permutation of set of jobs with same attribute and the permutation among set of jobs is conducted. Solution obtained from neighborhood search, which might be trapped in local solution, then is compared with other known optimal methods

    New Progress of Grey System Theory in The New Millennium

    Get PDF
    Purpose – The purpose of this paper is to summarize the progress in grey system research during 2000- 2015, so as to present some important new concepts, models, methods and a new framework of grey system theory. Design/methodology/approach –The new thinking, new models and new methods of grey system theory and their applications are presented in this paper. It includes algorithm rules of grey numbers based on the “Kernel” and the degree of greyness of grey numbers, the concept of general grey numbers, the synthesis axiom of degree of greyness of grey numbers and their operations; the general form of buffer operators of grey sequence operators; the four basic models of GM(1,1), such as Even Grey Model(EGM), Original Difference Grey Model(ODGM), Even Difference Grey Model(EDGM), Discrete Grey Model(DGM) and the suitable sequence type of each basic model, and suitable range of most used grey forecasting models; the similarity degree of grey incidences, the closeness degree of grey incidences and the three dimensional absolute degree of grey incidence of grey incidence analysis models; the grey cluster model based on center-point and end-point mixed triangular whitenization functions; the multi-attribute intelligent grey target decision model, the two stages decision model with grey synthetic measure of grey decision models; grey game models, grey input-output models of grey combined models; and the problems of robust stability for grey stochastic time-delay systems of neutral type, distributed-delay type and neutral distributed-delay type of grey control, etc. And the new framework of grey system theory is given as well. Findings –The problems which remain for further studying are discussed at the end of each section. The reader could know the general picture of research and developing trend of grey system theory from this paper. Practical implications – A lot of successful practical applications of the new models to solve various problems have been found in many different areas of natural science, social science, and engineering, including spaceflight, civil aviation, information, metallurgy, machinery, petroleum, chemical industry, electrical power, electronics, light industries, energy resources, transportation, medicine, health, agriculture, forestry, geography, hydrology, seismology, meteorology, environment protection, architecture, behavioral science, management science, law, education, military science, etc. These practical applications have brought forward definite and noticeable social and economic benefits. It demonstrates a wide range of applicability of grey system theory, especially in the situation where the available information is incomplete and the collected data are inaccurate. Originality/value –The reader is given a general picture of grey systems theory as a new model system and a new framework for studying problems where partial information is known; especially for uncertain systems with few data points and poor information. The problems remaining for further studying are identified at the end of each section. Keywords Grey systems theory, Operations of grey numbers, Buffer operators, Grey forecasting models, Grey incidence analysis models, Grey cluster evaluation models, Grey decision models, Combined grey models, Grey contro

    Resource conservation and allocation via process integration

    Get PDF
    Throughout the process industry, the conservation and allocation of mass and energy resources plays a pivotal role in the site wide optimization of a plant. Typically, raw materials are transformed into products, byproducts and wastes through pathways involving heating/cooling, pressure changes, mixing, reactions and separations. These pathways often require the addition or removal of energy from the system. The optimal management of such a system therefore requires conserving resources through the appropriate allocation of materials and energy. In a typical plant, there are both mass and energy objectives that require optimization. This dissertation will focus on optimizing the mass and energy resources present in a utility system. This will entail developing a novel framework of techniques to: target and design steam cogeneration networks while minimizing fuel requirements, identifying and utilizing sources of waste heat and incorporating heat pipes to enhance heat exchange networks. Additionally, a specific case of waste recovery will be examined when properties are the primary concern

    Nonlinear Optimization for Managing Occupational Exposure Risks in the Nanomaterial Manufacturing Workplace under Uncertainty

    Get PDF
    Critical environmental and human health concerns are associated with the rapidly growing fields of nanotechnology and Engineered nanomaterials (ENMs). The main risk arises from occupational exposure via chronic inhalation of nanoparticles. This research presents a fuzzy chance-constrained nonlinear programming (FCCNLP) optimization approach, which is developed to maximize the nanomaterial production and minimize the risks of workplace exposure to ENMs. The FCCNLP method integrates fuzzy mathematical programming (FMP) and chance-constrained programming (CCP) into nonlinear programming (NLP) optimization framework, and could be used to deal with uncertainties expressed as not only probability distributions and fuzzy values associated with components of constraints but ambiguity of the objective function as well. The FCCNLP method was examined through a single-walled carbon nanotube (SWNT) manufacturing process. Solutions of the compromise decision alternatives associated with different risk levels of relaxed constraint violations were obtained. This study confirmed that a high level control strategy through strict occupational exposure limits (OELs) combined with a high enforcement of OELs would lower the nanomaterial exposure risks to workers. The related cost and nanomaterial production have also been optimized for different operational scenarios under multi-layer system uncertainties. The results were helpful for decision makers to identify desirable schemes under uncertainties to maximize the economic benefits and ensure workplace safety through minimizing the nanomaterial-related health risks. The developed technology has technical novelty to help finding cost-effective measures for the sustainable development of nanotechnology

    Engineering Sustainability for the Future

    Get PDF
    The 38th International Manufacturing Conference, IMC38, showcases current research in the field of "manufacturing engineering" undertaken in Ireland by postgraduate students and experienced researchers. Indicative topics, in line with the contents of these proceedings, include; sustainable and energy efficient manufacturing, additive manufacturing, Industry 4.0 and digital manufacturing, machine tool, automation and manufacturing system design, surface engineering, forming and joining process research. The IMC community is also involved in research aimed at improving the learning experience of undergraduate and graduate engineers and developing high level skills for the manufacturing engineer of the future. The theme for this year’s conference is Sustainable Manufacturing, with a particular emphasis on a) Digitalisation of Manufacturing – its impact on sustainability and b) Addressing sustainability in Engineering Education, Industrial Training and CPD.Science Foundation Irelan

    Distributed Planning for Self-Organizing Production Systems

    Get PDF
    FĂŒr automatisierte Produktionsanlagen gibt es einen fundamentalen Tradeoff zwischen Effizienz und FlexibilitĂ€t. In den meisten FĂ€llen sind die AblĂ€ufe nicht nur durch den physischen Aufbau der Produktionsanlage, sondern auch durch die spezielle zugeschnittene Programmierung der Anlagensteuerung fest vorgegeben. Änderungen mĂŒssen aufwĂ€ndig in einer Vielzahl von Systemen nachgezogen werden. Das macht die Herstellung kleiner StĂŒckzahlen unrentabel. In dieser Dissertation wird ein Ansatz entwickelt, um eine automatische Anpassung des Verhaltens von Produktionsanlagen an wechselnde AuftrĂ€ge und Rahmenbedingungen zu erreichen. Dabei kommt das Prinzip der Selbstorganisation durch verteilte Planung zum Einsatz. Die aufeinander aufbauenden Ergebnisse der Dissertation sind wie folgt: 1. Es wird ein Modell von Produktionsanlagen entwickelt, dass nahtlos von der detaillierten Betrachtung physikalischer Produktionsprozesse bis hin zu Lieferbeziehungen zwischen Unternehmen skaliert. Im Vergleich zu existierenden Modellen von Produktionsanlagen werden weniger limitierende Annahmen gestellt. In diesem Sinne ist der Modellierungsansatz ein Kandidat fĂŒr eine hĂ€ufig geforderte "Theorie der Produktion". 2. FĂŒr die so modellierten Szenarien wird ein Algorithmus zur Optimierung der nebenlĂ€ufigen AblĂ€ufe entwickelt. Der Algorithmus verbindet Techniken fĂŒr die kombinatorische und die kontinuierliche Optimierung: Je nach Detailgrad und Ausgestaltung des modellierten Szenarios kann der identische Algorithmus kombinatorische Fertigungsfeinplanung (Scheduling) vornehmen, weltweite Lieferbeziehungen unter Einbezug von Unsicherheiten und Risiko optimieren und physikalische Prozesse prĂ€diktiv regeln. DafĂŒr werden Techniken der Monte-Carlo Baumsuche (die auch bei Deepminds Alpha Go zum Einsatz kommen) weiterentwickelt. Durch Ausnutzung zusĂ€tzlicher Struktur in den Modellen skaliert der Ansatz auch auf große Szenarien. 3. Der Planungsalgorithmus wird auf die verteilte Optimierung durch unabhĂ€ngige Agenten ĂŒbertragen. DafĂŒr wird die sogenannte "Nutzen-Propagation" als Koordinations-Mechanismus entwickelt. Diese ist von der Belief-Propagation zur Inferenz in Probabilistischen Graphischen Modellen inspiriert. Jeder teilnehmende Agent hat einen lokalen Handlungsraum, in dem er den Systemzustand beobachten und handelnd eingreifen kann. Die Agenten sind an der Maximierung der Gesamtwohlfahrt ĂŒber alle Agenten hinweg interessiert. Die dafĂŒr notwendige Kooperation entsteht ĂŒber den Austausch von Nachrichten zwischen benachbarten Agenten. Die Nachrichten beschreiben den erwarteten Nutzen fĂŒr ein angenommenes Verhalten im Handlungsraum beider Agenten. 4. Es wird eine Beschreibung der wiederverwendbaren FĂ€higkeiten von Maschinen und Anlagen auf Basis formaler Beschreibungslogiken entwickelt. Ausgehend von den beschriebenen FĂ€higkeiten, sowie der vorliegenden AuftrĂ€ge mit ihren notwendigen Produktionsschritten, werden ausfĂŒhrbare Aktionen abgeleitet. Die ausfĂŒhrbaren Aktionen, mit wohldefinierten Vorbedingungen und Effekten, kapseln benötigte Parametrierungen, programmierte AblĂ€ufe und die Synchronisation von Maschinen zur Laufzeit. Die Ergebnisse zusammenfassend werden Grundlagen fĂŒr flexible automatisierte Produktionssysteme geschaffen -- in einer Werkshalle, aber auch ĂŒber Standorte und Organisationen verteilt -- welche die ihnen innewohnenden Freiheitsgrade durch Planung zur Laufzeit und agentenbasierte Koordination gezielt einsetzen können. Der Bezug zur Praxis wird durch Anwendungsbeispiele hergestellt. Die Machbarkeit des Ansatzes wurde mit realen Maschinen im Rahmen des EU-Projekts SkillPro und in einer Simulationsumgebung mit weiteren Szenarien demonstriert

    Distributed Planning for Self-Organizing Production Systems

    Get PDF
    In dieser Arbeit wird ein Ansatz entwickelt, um eine automatische Anpassung des Verhaltens von Produktionsanlagen an wechselnde AuftrÀge und Rahmenbedingungen zu erreichen. Dabei kommt das Prinzip der Selbstorganisation durch verteilte Planung zum Einsatz

    Clemson Catalog, 1992-1993, Volume 67

    Get PDF
    https://tigerprints.clemson.edu/clemson_catalog/1145/thumbnail.jp

    Sustainable Industrial Engineering along Product-Service Life Cycle/Supply Chain

    Get PDF
    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
    • 

    corecore