Open Shop Scheduling with Synchronization

In this paper, we study open shop scheduling problems with synchronization. This model has the same features as the classical open shop model, where each of the n jobs has to be processed by each of the m machines in an arbitrary order. Unlike the classical model, jobs are processed in synchronous cycles, which means that the m operations of the same cycle start at the same time. Within one cycle, machines which process operations with smaller processing times have to wait until the longest operation of the cycle is finished before the next cycle can start. Thus, the length of a cycle is equal to the maximum processing time of its operations. In this paper, we continue the line of research started by Weiß et al. (Discrete Appl Math 211:183–203, 2016). We establish new structural results for the two-machine problem with the makespan objective and use them to formulate an easier solution algorithm. Other versions of the problem, with the total completion time objective and those which involve due dates or deadlines, turn out to be NP-hard in the strong sense, even for m=2 machines. We also show that relaxed models, in which cycles are allowed to contain less than m jobs, have the same complexity status

A Lower Bound Technique for Communication in BSP

Communication is a major factor determining the performance of algorithms on current computing systems; it is therefore valuable to provide tight lower bounds on the communication complexity of computations. This paper presents a lower bound technique for the communication complexity in the bulk-synchronous parallel (BSP) model of a given class of DAG computations. The derived bound is expressed in terms of the switching potential of a DAG, that is, the number of permutations that the DAG can realize when viewed as a switching network. The proposed technique yields tight lower bounds for the fast Fourier transform (FFT), and for any sorting and permutation network. A stronger bound is also derived for the periodic balanced sorting network, by applying this technique to suitable subnetworks. Finally, we demonstrate that the switching potential captures communication requirements even in computational models different from BSP, such as the I/O model and the LPRAM

Information visualization for business applications

Business applications are generating ever-increasing amounts of data, and more and more of [these] data are in real-time data. Data mining is a standard feature in most data management system[s] for retrieving complex information but the challenge is about how to represent [this] information in an effective way for better analysis and decision making. With this rich information, the challenge still remains to derive the most business value from [an] ever-increasing amount of available information. Information visualization can significantly solve this problem for handling such complex and high volumes of data to be represented in business applications. Through this research, an attempt will be made to solve this problem by prototyping an interactive data driven business application through visualization. The key focus of this research work will be given in the \u27Presentation Tier\u27 of a business application for visually representing the information in an aesthetic matter for better understanding

Manufacturing System Design Framework Manual

Previous Lean Aerospace Initiative research in factory operations had indicated that the greatest performance gains are realized when the manufacturing system is designed from the top down and from supplier to the customer. Manufacturing system designs were most effective when the entire product value stream was designed or redesigned (not just a shop, division or segment of the factory). This led to a focus on manufacturing system design. The objective in this study was to develop a method or process that would assist manufacturing system designers as they developed (or modified) the manufacturing system for their needs. This effort was developed to be applicable to a single product manufacturing system design or a multiple product manufacturing system design. A systems approach was used with an enterprise perspective. Several important products were produced as the problem was addressed: a list of the manufacturing system design inputs and a definition of manufacturing system types (each included in the appendices)

Batch Sizing and Lot Splitting Strategies to Reduce Cycle Time in Semiconductor Assembly Process

Increasingly, products with customized features are manufactured in small batches based on demand by unique customers. Such diversity leads to high product mix, thus severely impacting both production planning and scheduling activities such as frequent equipment setup and conversion. Despite increased complexity, production continues being pressured on minimal cycle time to meet on-time delivery requirements. Focusing on the most challenging process, which is assembly, this paper presents batch sizing and lot splitting strategies to improve production cycle times. In the event of too short cycle time, overlapping technique is the most applicable, while “parallel” technique applies to normal cycle time. The commonly known “batch queue” technique works well for long cycle time such as new product qualification lot

Proceedings, MSVSCC 2018

Proceedings of the 12th Annual Modeling, Simulation & Visualization Student Capstone Conference held on April 19, 2018 at VMASC in Suffolk, Virginia. 155 pp

Introduction: The Fourth International Workshop on Epigenetic Robotics

As in the previous editions, this workshop is trying to be a forum for multi-disciplinary research ranging from developmental psychology to neural sciences (in its widest sense) and robotics including computational studies. This is a two-fold aim of, on the one hand, understanding the brain through engineering embodied systems and, on the other hand, building artificial epigenetic systems. Epigenetic contains in its meaning the idea that we are interested in studying development through interaction with the environment. This idea entails the embodiment of the system, the situatedness in the environment, and of course a prolonged period of postnatal development when this interaction can actually take place. This is still a relatively new endeavor although the seeds of the developmental robotics community were already in the air since the nineties (Berthouze and Kuniyoshi, 1998; Metta et al., 1999; Brooks et al., 1999; Breazeal, 2000; Kozima and Zlatev, 2000). A few had the intuition – see Lungarella et al. (2003) for a comprehensive review – that, intelligence could not be possibly engineered simply by copying systems that are “ready made” but rather that the development of the system fills a major role. This integration of disciplines raises the important issue of learning on the multiple scales of developmental time, that is, how to build systems that eventually can learn in any environment rather than program them for a specific environment. On the other hand, the hope is that robotics might become a new tool for brain science similarly to what simulation and modeling have become for the study of the motor system. Our community is still pretty much evolving and “under construction” and for this reason, we tried to encourage submissions from the psychology community. Additionally, we invited four neuroscientists and no roboticists for the keynote lectures. We received a record number of submissions (more than 50), and given the overall size and duration of the workshop together with our desire to maintain a single-track format, we had to be more selective than ever in the review process (a 20% acceptance rate on full papers). This is, if not an index of quality, at least an index of the interest that gravitates around this still new discipline

An investigation into manufacturing execution systems

Hardware and software developments of this decade have exposed an hiatus between business/management applications and process control in heavy industry in the implementation of computer technology. This document examines the development of discrete manufacturing and of relevant implementations of computing. It seeks to examine and to clarify the issues involved in a perceived current drive to bridge this gap, to integrate all the systems in a manufacturing enterprise in a Manufacturing Execution System (MES) in order to address two hypotheses: I) That overseas trends towards the development of manufacturing execution systems have application in the Australian industrial context. 2) That significant gains in production efficiency and quality may be achieved by the application of an MES. It became apparent early in this study that any understanding the function of an MES requires an understanding of the context in which it works. Following the Introduction, therefore, Section Two contains a brief overview of the history and development of modem industry with particular attention to the subject of inventory and inventory management. Since the 1970s, three main streams of change in manufacturing management methodology developed. These are dealt with in some detail in Section Three. Section Four outlines a variety of areas of increasing computerisation on the shop floor while Section Five addresses the integration of the whole system, management and shop floor, seeking to demonstrate the complexity of the subject and to discover current trends and developments. Section Five includes a survey of some of the software and hardware options currently available and Section Six summarises the work and presents some observations and conclusions. Three appendices provide more detailed information on MES software availability, pricing and market penetratio