Learning to monitor a machine tool

This paper deals with the issue of automatic learning and recognition of various conditions of a machine tool. The ultimate goal of the research discussed in this paper is to develop a comparehensive monitor and control (M&C) system that can substitute for the expert machinist and perform certain critical in-process tasks to assure quality production. The M&C system must reliably recognize and respond to qualitatively different behaviours of the machine tool, learn new behaviors, respond faster than its human counterpart to quality threatening circumstances, and interface with an existing controller. The research considers a series of face-milling anomalies that were subsequently simulated and used as a first step towards establishing the feasibility of employing machine learning as an integral component of the intelligent controller. We address the question of feasibility in two steps. First, it is important to know if the process models (dull tool, broken tool, etc.) can be learned (model learning). And second, if the models are learned, can an algorithm reliably select an appropriate model (distinguish between dull and broken tools) based on input from the model learner and from the sensors (model selection). The results of the simulation-based tests demonstrate that the milling-process anomalies can be learned, and the appropriate model can be reliably selected. Such a model can be subsequently utilized to make compensating in-process machine-tool adjustments. In addition, we observed that the learning curve need not approach the 100% level to be functional.     

Learning procedures in machine tool monitoring

The unmanned operation of machine tools and manufacturing systems requires the integration of recently developed special purpose monotiring equipment. In this paper the pattern recognition model of monitoring problems and its use in general purpose monitoring systems are discussed. Following a brief survey of the available discriminant functions and learning procedures, a realized on-line monitoring system with pattern recognition facilities and some results are presented.     

Learning finite-state models for machine translation

In formal language theory, finite-state transducers are well-know models for simple “input-output” mappings between two languages. Even if more powerful, recursive models can be used to account for more complex mappings, it has been argued that the input-output relations underlying most usual natural language pairs can essentially be modeled by finite-state devices. Moreover, the relative simplicity of these mappings has recently led to the development of techniques for learning finite-state transducers from a training set of input-output sentence pairs of the languages considered. In the last years, these techniques have lead to the development of a number of machine translation systems. Under the statistical statement of machine translation, we overview here how modeling, learning and search problems can be solved by using stochastic finite-state transducers. We also review the results achieved by the systems we have developed under this paradigm. As a main conclusion of this review we argue that, as task complexity and training data scarcity increase, those systems which rely more on statistical techniques tend produce the best results. This work was partially supported by the European Union project TT2 (IST-2001-32091) and by the Spanish project ITEFTE (TIC 2003-08681-C02-02). Editor: Georgios Paliouras and Yasubumi Sakakibara     

Learning policies for single machine job dispatching

Reinforcement learning (RL) has received some attention in recent years from agent-based researchers because it deals with the problem of how an autonomous agent can learn to select proper actions for achieving its goals through interacting with its environment. Each time after an agent performs an action, the environment's response, as indicated by its new state, is used by the agent to reward or penalize its action. The agent's goal is to maximize the total amount of reward it receives over the long run. Although there have been several successful examples demonstrating the usefulness of RL, its application to manufacturing systems has not been fully explored. In this study, a single machine agent employs the Q-learning algorithm to develop a decision-making policy on selecting the appropriate dispatching rule from among three given dispatching rules. The system objective is to minimize mean tardiness. This paper presents a factorial experiment design for studying the settings used to apply Q-learning to the single machine dispatching rule selection problem. The factors considered in this study include two related to the agent's policy table design and three for developing its reward function. This study not only investigates the main effects of this Q-learning application but also provides recommendations for factor settings and useful guidelines for future applications of Q-learning to agent-based production scheduling.     

Exploring the resources,competencies, and capabilities needed for successful machine learning projects in digital marketing

Information Systems and e-Business Management - This study aimed to explore the organizational resources, competencies, and capabilities needed for the successful implementation of machine learning...     

Learning the set covering machine by bound minimization and margin-sparsity trade-off

We investigate classifiers in the sample compression framework that can be specified by two distinct sources of information: a compression set and a message string of additional information. In the compression setting, a reconstruction function specifies a classifier when given this information. We examine how an efficient redistribution of this reconstruction information can lead to more general classifiers. In particular, we derive risk bounds that can provide an explicit control over the sparsity of the classifier and the magnitude of its separating margin and a capability to perform a margin-sparsity trade-off in favor of better classifiers. We show how an application to the set covering machine algorithm results in novel learning strategies. We also show that these risk bounds are tighter than their traditional counterparts such as VC-dimension and Rademacher complexity-based bounds that explicitly take into account the hypothesis class complexity. Finally, we show how these bounds are able to guide the model selection for the set covering machine algorithm enabling it to learn by bound minimization.     

Learning dataset representation for automatic machine learning algorithm selection

The algorithm selection problem is defined as identifying the best-performing machine learning (ML) algorithm for a given combination of dataset, task, and evaluation measure. The human expertise required to evaluate the increasing number of ML algorithms available has resulted in the need to automate the algorithm selection task. Various approaches have emerged to handle the automatic algorithm selection challenge, including meta-learning. Meta-learning is a popular approach that leverages accumulated experience for future learning and typically involves dataset characterization. Existing meta-learning methods often represent a dataset using predefined features and thus cannot be generalized across different ML tasks, or alternatively, learn a dataset’s representation in a supervised manner and therefore are unable to deal with unsupervised tasks. In this study, we propose a novel learning-based task-agnostic method for producing dataset representations. Then, we introduce TRIO, a meta-learning approach, that utilizes the proposed dataset representations to accurately recommend top-performing algorithms for previously unseen datasets. TRIO first learns graphical representations for the datasets, using four tools to learn the latent interactions among dataset instances and then utilizes a graph convolutional neural network technique to extract embedding representations from the graphs obtained. We extensively evaluate the effectiveness of our approach on 337 datasets and 195 ML algorithms, demonstrating that TRIO significantly outperforms state-of-the-art methods for algorithm selection for both supervised (classification and regression) and unsupervised (clustering) tasks.

     

Discovery and prediction capabilities in metal-based nanomaterials: An overview of the application of machine learning techniques and some recent advances

The application of machine learning (ML) techniques to metal-based nanomaterials has contributed greatly to understanding the interaction of nanoparticles, properties prediction, and new materials discovery. However, the prediction accuracy and efficiency of distinctive ML algorithms differ with different metal-based nanomaterials problems. This, alongside the high dimensionality and nonlinearity of available datasets in metal-based nanomaterials problems, makes it imperative to review recent advances in the implementation of ML techniques for these kinds of problems. In addition to understanding the applicability of different ML algorithms to various kinds of metal-based nanomaterials problems, it is hoped that this work will help facilitate understanding and promote interest in this emerging and less explored area of materials informatics. The scope of this review covers the introduction of metal-based nanomaterials, several techniques used in generating datasets for training ML models, feature engineering techniques used in nanomaterials-machine learning applications, and commonly applied ML algorithms. Then, we present the recent advances in ML applications to metal-based nanomaterials, with emphasis on the procedure and efficiency of algorithms used for such applications. In the concluding section, we identify the most common and efficient algorithms for distinctive property predictions. The common problems encountered in ML applications for metal-based nanoinformatics were mentioned. Finally, we propose suitable solutions and future outlooks for various challenges in metal-based nanoinformatics research.     

Learning with positive and unlabeled examples using biased twin support vector machine

PU classification problem (‘P’ stands for positive, ‘U’ stands for unlabeled), which is defined as the training set consists of a collection of positive and unlabeled examples, has become a research hot spot recently. In this paper, we design a new classification algorithm to solve the PU problem: biased twin support vector machine (B-TWSVM). In B-TWSVM, two nonparallel hyperplanes are constructed such that the positive examples can be classified correctly, and the number of unlabeled examples classified as positive is minimized. Moreover, considering that the unlabeled set also contains positive data, different penalty parameters for positive and negative data are allowed in B-TWSVM. Experimental results demonstrate that our method outperforms the state-of-the-art methods in most cases.     

Learning in context: enhancing machine learning with context-based reasoning

This article describes how an experiment to train an agent to perform a task, which had originally failed, was made successful by incorporating a contextual structure that decomposed the tasks into contexts through Context-based Reasoning. The task involved a simulation of a crane that was used by a human operator to move boxes from arbitrary locations throughout a wide area to a designated drop off location in the environment. Initial attempts to teach an agent how to perform the task through observation in a context-free manner yielded poor performance. However, when the task to be learned was decomposed into separate contexts and the agents learned each context independently, the performance improved significantly. The paper describes the process that enabled the improvements achieved and discusses the tests and results that demonstrated the improvement.     

The center location-dependent relocation problem with a probabilistic line barrier

This paper presents a new mixed-integer nonlinear programming (MINLP) for a multi-period rectilinear distance center location-dependent relocation problem in the presence of a probabilistic line-shaped barrier that uniformly occurs on a given horizontal route. In this problem, the demand and location of the existing facilities have a dynamic nature and the relocation is dependent to the location of new facilities in previous period. The objective function of the presented model is to minimize the maximum expected weighted barrier distance between the new facility and the existing facilities during the planning horizon. The optimum solution of small-sized test problems is obtained by the optimization software. For large-size test problems which the optimization software is unable to find the optimum solution in the runtime limitation, two meta-heuristics based on the genetic algorithm (GA) and imperialist competitive algorithm (ICA) are applied. To validate the meta-heuristics, a lower bound problem based on the forbidden region instead of the line barrier is generated. Related results of numerical experiments are illustrated and are then compared.     

PKM capabilities and applications exploration in a collaborative virtual environment

This paper introduces an integrated validation system that consists of the following modular components: kinematic/dynamic analysis module, kinetostatic model, CAD module, FEM module, CAM module, optimization module and virtual environment for remote control. In this paper, authors focus mainly on the modules of kinetostatic modeling, dynamic modeling, PKM design optimization and remote control realization. The prototype of a 3-dof Parallel Kinematic Machine (PKM) developed at the Integrated Manufacturing Technologies Institute of National Research Council of Canada (NRC-IMTI) is used as an example throughout this paper.     

Dynamic management of capabilities in a network aware coordination language

We introduce a capability-based access control model integrated into a linguistic formalism for modeling network aware systems and applications. Our access control model enables specification and dynamic modification of policies for controlling process activities (mobility of code and access to resources). We exploit a combination of static and dynamic checking and of in-lined reference monitoring to guarantee absence of run-time errors due to lack of capabilities. We illustrate the usefulness of our framework by using it for implementing a simplified but realistic scenario. Finally, we show how the model can be easily tailored for dealing with different forms of capability acquisition and loss, thus enabling different possible variations of access control policies.     

Dynamic relocation of hybrid tasks: Strategies and methodologies

Reconfiguration-based architectures are increasingly gaining attention of designers due to their benefits of flexibility, re-programmability and high computational performance. The combination of general purpose processors and reconfigurable fabrics (e.g., FPGAs), may provide those valuable characteristics, which are becoming essential for modern and future embedded systems. Such hybrid systems permit the existence of hardware tasks, which shall be properly managed by the operating system, thus allowing for their coexistence with software tasks. Nevertheless, in order to completely exploit this feature, the operating system must be capable of relocating a task between hardware and software execution domains. Runtime relocation of tasks (including preemption and resumption) between two devices following different computation paradigms (parallel vs. instruction based) however is a challenging job. In this work we propose a comprehensive and embracing methodology, which starts from a unified task representation, and goes to the final implementation of such hybrid tasks. For its accomplishment, a framework is proposed to help the user in designing a hybrid task, which also generates automatically the underlying infrastructure that is in charge of performing the dynamic relocation of a hybrid task. In order to prove the applicability of our concept and the efficiency of our framework, a case study is presented including its results.