Genetic algorithms for hyperparameter optimization in predictive business process monitoring

Predictive business process monitoring exploits event logs to predict how ongoing (uncompleted) traces will unfold up to their completion. A predictive process monitoring framework collects a range of techniques that allow users to get accurate predictions about the achievement of a goal for a given ongoing trace. These techniques can be combined and their parameters configured in different framework instances. Unfortunately, a unique framework instance that is general enough to outperform others for every dataset, goal or type of prediction is elusive. Thus, the selection and configuration of a framework instance needs to be done for a given dataset. This paper presents a predictive process monitoring framework armed with a hyperparameter optimization method to select a suitable framework instance for a given dataset

Improving stroke diagnosis accuracy using hyperparameter optimized deep learning

Stroke may cause death for anyone, including youngsters. One of the early stroke detection techniques is a Computerized Tomography (CT) scan. This research aimed to optimize hyperparameter in Deep Learning, Random Search and Bayesian Optimization for determining the right hyperparameter. The CT scan images were processed by scaling, grayscale, smoothing, thresholding, and morphological operation. Then, the images feature was extracted by the Gray Level Co-occurrence Matrix (GLCM). This research was performed a feature selection to select relevant features for reducing computing expenses, while deep learning based on hyperparameter setting was used to the data classification process. The experiment results showed that the Random Search had the best accuracy, while Bayesian Optimization excelled in optimization time

A New K means Grey Wolf Algorithm for Engineering Problems

Purpose: The development of metaheuristic algorithms has increased by researchers to use them extensively in the field of business, science, and engineering. One of the common metaheuristic optimization algorithms is called Grey Wolf Optimization (GWO). The algorithm works based on imitation of the wolves' searching and the process of attacking grey wolves. The main purpose of this paper to overcome the GWO problem which is trapping into local optima. Design or Methodology or Approach: In this paper, the K-means clustering algorithm is used to enhance the performance of the original Grey Wolf Optimization by dividing the population into different parts. The proposed algorithm is called K-means clustering Grey Wolf Optimization (KMGWO). Findings: Results illustrate the efficiency of KMGWO is superior to GWO. To evaluate the performance of the KMGWO, KMGWO applied to solve 10 CEC2019 benchmark test functions. Results prove that KMGWO is better compared to GWO. KMGWO is also compared to Cat Swarm Optimization (CSO), Whale Optimization Algorithm-Bat Algorithm (WOA-BAT), and WOA, so, KMGWO achieves the first rank in terms of performance. Statistical results proved that KMGWO achieved a higher significant value compared to the compared algorithms. Also, the KMGWO is used to solve a pressure vessel design problem and it has outperformed results. Originality/value: Results prove that KMGWO is superior to GWO. KMGWO is also compared to cat swarm optimization (CSO), whale optimization algorithm-bat algorithm (WOA-BAT), WOA, and GWO so KMGWO achieved the first rank in terms of performance. Also, the KMGWO is used to solve a classical engineering problem and it is superiorComment: 15 pages. World Journal of Engineering, 202

Phishing website detection using genetic algorithm-based feature selection and parameter hypertuning

Dissertation presented as the partial requirement for obtaining a Master's degree in Data Science and Advanced Analytics, specialization in Business AnalyticsFalse webpages are created by cyber attackers who seek to mislead users into revealing sensitive and personal information, from credit card details to passwords. Phishing is a class of cyber attacks that mislead users into clicking on false websites, logging into related accounts, and subsequently stealing funds. This cyberattack increases annually given the exponential increase of e-commerce customers, which causes difficulty to distinguish between harmless and false websites. The conventional methods to detect phishing websites are focused on a database of blacklisted and whitelisted. Such methods are not capable to detect new phishing websites. To solve this problem, researchers are developing machine learning (ML) and deep learning-based methods. In this dissertation, a hybrid-based solution, which uses genetic algorithms and ML algorithms for phishing detection based on the URL of the website is proposed. Regarding evaluation, comparisons between conventional ML and DL models are performed using various feature sets resulting from commonly used feature selection methods, such as mutual information and recursive feature elimination. This dissertation proposes a final model with an accuracy of 95.34% on the test set

Predictive Process Model Monitoring using Recurrent Neural Networks

The field of predictive process monitoring focuses on modelling future characteristics of running business process instances, typically by either predicting the outcome of particular objectives (e.g. completion (time), cost), or next-in-sequence prediction (e.g. what is the next activity to execute). This paper introduces Processes-As-Movies (PAM), a technique that provides a middle ground between these predictive monitoring. It does so by capturing declarative process constraints between activities in various windows of a process execution trace, which represent a declarative process model at subsequent stages of execution. This high-dimensional representation of a process model allows the application of predictive modelling on how such constraints appear and vanish throughout a process' execution. Various recurrent neural network topologies tailored to high-dimensional input are used to model the process model evolution with windows as time steps, including encoder-decoder long short-term memory networks, and convolutional long short-term memory networks. Results show that these topologies are very effective in terms of accuracy and precision to predict a process model's future state, which allows process owners to simultaneously verify what linear temporal logic rules hold in a predicted process window (objective-based), and verify what future execution traces are allowed by all the constraints together (trace-based)

Elaboración de una metodología de trabajo para el tratamiento y la predicción de series temporales de consumo de agua potable

[ES] El presente trabajo consiste en la elaboración de una metodología para el análisis de una serie temporal de caudal de agua potable en un sector hidráulico de tipo domiciliario de una ciudad de la provincia de Valencia (España). Esta metodología aborda la reconstrucción de la serie temporal mediante la imputación de valores faltantes, la corrección de valores anómalos y la predicción del consumo a corto plazo mediante el uso de técnicas de machine learning y deep learning. La investigación llevada a cabo propone una metodología novedosa, puesto que en la literatura científica relacionada con este ámbito no se ha abordado el problema del tratamiento de este tipo de series temporales de manera integral. La metodología desarrollada, por lo tanto, pretende ser la semilla de un sistema de ayuda para la toma de decisiones que permita decidir, para cada tipo de serie temporal de caudal de agua potable o similares, cuál es la estrategia idónea que debe seguir el analista para optimizar la predicción del consumo en un sector hidráulico, y por ende, la operación del propio sistema de distribución asociado.[EN] The following research consists in the elaboration of a methodology for the analysis of a time series of drinking water flow rate in a domestic hydraulic sector of a city in the province of Valencia (Spain). This methodology deals with the reconstruction of the time series through the imputation of missing values, the correction of outliers and the forecasting of short-term consumption using machine learning and deep learning techniques. The conducted research proposes a novel methodology since the treatment of this kind of time series has not been addressed in a comprehensive way in the scientific literature related to this field. The developed methodology, aims to be the seed of a decision support system that allows to decide, for each kind of time series of drinking water flow rate or similar, which is the ideal strategy to be followed by the analyst to optimize the forecast of the flow rate in a hydraulic sector, and therefore, the operation of the associated distribution system.Morer, FE. (2020). Elaboración de una metodología de trabajo para el tratamiento y la predicción de series temporales de consumo de agua potable. Universitat Politècnica de València. http://hdl.handle.net/10251/159161TFG

Machine Learning Methods for Rapid Inspection of Automated Fiber Placement Manufactured Composite Structures

The advanced manufacturing capabilities provided through the automated fiber placement (AFP) system has allowed for faster layup time and more consistent production across a number of different geometries. This contributes to the modern production of large composite structures and the widespread adaptation of composites in industry in general and aerospace in particular. However, the automation introduced in this process increases the difficulty of quality assurance efforts and inspection. The AFP process can induce a number of manufacturing defects including wrinkles, twists, gaps, and overlaps. The manual identification of these defects is often laborious and requires a measure of expert knowledge. A software package for the assistance of the inspection process has been used in conjunction with automated inspection hardware for the automated inspection, identification, and characterization of AFP manufacturing defects. Image analysis algorithms were developed and demonstrated on a number of defect types. Defects are identified in scan images and exact size and shape characteristics are extracted for export

Managing computational complexity through using partitioning, approximation and coordination

Problem: Complex systems are composed of many interdependent subsystems with a level of complexity that exceeds the ability of a single designer. One way to address this problem is to partition the complex design problem into smaller, more manageable design tasks that can be handled by multiple design teams. Partitioning-based design methods are decision support tools that provide mathematical foundations, and computational methods to create such design processes. Managing the interdependency among these subsystems is crucial and a successful design process should meet the requirements of the whole system which needs coordinating the solutions for all the partitions after all. Approach: Partitioning and coordination should be performed to break down the system into subproblems, solve them and put these solutions together to come up with the ultimate system design. These two tasks of partitioning-coordinating are computationally demanding. Most of the proposed approaches are either computationally very expensive or applicable to only a narrow class of problems. These approaches also use exact methods and eliminate the uncertainty. To manage the computational complexity and uncertainty, we approximate each subproblem after partitioning the whole system. In engineering design, one way to approximate the reality is using surrogate models (SM) to replace the functions which are computationally expensive to solve. This task also is added to the proposed computational framework. Also, to automate the whole process, creating a knowledge-based reusable template for each of these three steps is required. Therefore, in this dissertation, we first partition/decompose the complex system, then, we approximate the subproblem of each partition. Afterwards, we apply coordination methods to guide the solutions of the partitions toward the ultimate integrated system design. Validation: The partitioning-approximation-coordination design approach is validated using the validation square approach that consists of theoretical and empirical validation. Empirical validation of the design architecture is carried out using two industry-driven problems namely the a hot rod rolling problem’, ‘a dam network design problem’, ‘a crime prediction problem’ and ‘a green supply chain design problem’. Specific sub-problems are formulated within these problem domains to address various research questions identified in this dissertation. Contributions: The contributions from the dissertation are categorized into new knowledge in five research domains: • Creating an approach to building an ensemble of surrogate models when the data is limited – when the data is limited, replacing computationally expensive simulations with accurate, low-dimensional, and rapid surrogates is very important but non-trivial. Therefore, a cross-validation-based ensemble modeling approach is proposed. • Using temporal and spatial analysis to manage the uncertainties - when the data is time-based (for example, in meteorological data analysis) and when we are dealing with geographical data (for example, in geographical information systems data analysis), instead of feature-based data analysis time series analysis and spatial statistics are required, respectively. Therefore, when the simulations are for time and space-based data, surrogate models need to be time and space-based. In surrogate modeling, there is a gap in time and space-based models which we address in this dissertation. We created, applied and evaluated the effectiveness of these models for a dam network planning and a crime prediction problem. • Removing assumptions regarding the demand distributions in green supply chain networks – in the existent literature for supply chain network design, there are always assumptions about the distribution of the demand. We remove this assumption in the partition-approximate-compose of the green supply chain design problem. • Creating new knowledge by proposing a coordination approach for a partitioned and approximated network design. A green supply chain under online (pull economy) and in-person (push economy) shopping channels is designed to demonstrate the utility of the proposed approach