Nearest Neighbor Methods
PCA, LDA, and SVD: Model Tuning Through Feature Reduction for Transportation POI Classification
PCA is a dimension reduction method that takes datasets with a large number of features and reduces them to a few underlying features. The sklearn PCA package performs this process for us. In the snippet of code below we are reducing the 75 features that the initial dataset has into 8 features. This snippet serves to show the optimal number of features for the feature reduction algorithm to fit into. The below snippets will show how to use the Gaussian Naive Bayes, Decision Tree, and the K-Nearest Neighbors Classifiers with the reduced features.
Efficient Detection of Botnet Traffic by features selection and Decision Trees
Velasco-Mata, Javier, Gonzรกlez-Castro, Vรญctor, Fidalgo, Eduardo, Alegre, Enrique
Botnets are one of the online threats with the biggest presence, causing billionaire losses to global economies. Nowadays, the increasing number of devices connected to the Internet makes it necessary to analyze large amounts of network traffic data. In this work, we focus on increasing the performance on botnet traffic classification by selecting those features that further increase the detection rate. For this purpose we use two feature selection techniques, Information Gain and Gini Importance, which led to three pre-selected subsets of five, six and seven features. Then, we evaluate the three feature subsets along with three models, Decision Tree, Random Forest and k-Nearest Neighbors. To test the performance of the three feature vectors and the three models we generate two datasets based on the CTU-13 dataset, namely QB-CTU13 and EQB-CTU13. We measure the performance as the macro averaged F1 score over the computational time required to classify a sample. The results show that the highest performance is achieved by Decision Trees using a five feature set which obtained a mean F1 score of 85% classifying each sample in an average time of 0.78 microseconds.
Modeling Pipeline Optimization With scikit-learn
This tutorial presents two essential concepts in data science and automated learning. One is the machine learning pipeline, and the second is its optimization. These two principles are the key to implementing any successful intelligent system based on machine learning. A machine learning pipeline can be created by putting together a sequence of steps involved in training a machine learning model. It can be used to automate a machine learning workflow.
ASK: Adversarial Soft k-Nearest Neighbor Attack and Defense
Wang, Ren, Chen, Tianqi, Yao, Philip, Liu, Sijia, Rajapakse, Indika, Hero, Alfred
K-Nearest Neighbor (kNN)-based deep learning methods have been applied to many applications due to their simplicity and geometric interpretability. However, the robustness of kNN-based classification models has not been thoroughly explored and kNN attack strategies are underdeveloped. In this paper, we propose an Adversarial Soft kNN (ASK) loss to both design more effective kNN attack strategies and to develop better defenses against them. Our ASK loss approach has two advantages. First, ASK loss can better approximate the kNN's probability of classification error than objectives proposed in previous works. Second, the ASK loss is interpretable: it preserves the mutual information between the perturbed input and the kNN of the unperturbed input. We use the ASK loss to generate a novel attack method called the ASK-Attack (ASK-Atk), which shows superior attack efficiency and accuracy degradation relative to previous kNN attacks. Based on the ASK-Atk, we then derive an ASK-Defense (ASK-Def) method that optimizes the worst-case training loss induced by ASK-Atk.
The Story of Machine Learning
The first case of neural networks was in 1943, when neurophysiologist Warren McCulloch and mathematician Walter Pitts wrote a paper about neurons, and how they work. They decided to create a model of this using an electrical circuit, and therefore the neural network was born. In 1950, Alan Turing created the world-famous Turing Test. This test is fairly simple for a computer to pass, it has to be able to convince a human that it is a human and not a computer. It was a game which played checkers, created by Arthur Samuel.
EMG Signal Classification Using Reflection Coefficients and Extreme Value Machine
Azhiri, Reza Bagherian, Esmaeili, Mohammad, Jafarzadeh, Mohsen, Nourani, Mehrdad
Electromyography is a promising approach to the gesture recognition of humans if an efficient classifier with high accuracy is available. In this paper, we propose to utilize Extreme Value Machine (EVM) as a high-performance algorithm for the classification of EMG signals. We employ reflection coefficients obtained from an Autoregressive (AR) model to train a set of classifiers. Our experimental results indicate that EVM has better accuracy in comparison to the conventional classifiers approved in the literature based on K-Nearest Neighbors (KNN) and Support Vector Machine (SVM).
Machine Learning in Enzyme Engineering
Enzyme engineering is the process of customizing new biocatalysts with improved properties by altering their constituting sequences of amino acids. Despite the immensity of possible alterations, this procedure has already yielded remarkable results in new designs and optimization of enzymes for chemical and pharmaceutical biosynthesis, regenerative medicine, food production, waste biodegradation and biosensing.(1 The two established and widely used enzyme engineering strategies are rational design(5,6) and directed evolution.(7,8) The former approach is based on the structural analysis and in-depth computational modeling of enzymes by accounting for the physicochemical properties of amino acids and simulating their interactions with the environment. The latter approach takes after the natural evolution in using mutagenesis for iterative production of mutant libraries, which are then screened for enzyme variants with the desired properties. These two strategies may naturally complement each other: e.g., site-directed or saturation mutagenesis may be applied on the rationally chosen hotspots.(9)
Performance Evaluation of Classification Models for Household Income, Consumption and Expenditure Data Set
Nigus, Mersha, Dorsewamy, null
Food security is more prominent on the policy agenda today than it has been in the past, thanks to recent food shortages at both the regional and global levels as well as renewed promises from major donor countries to combat chronic hunger. One field where machine learning can be used is in the classification of household food insecurity. In this study, we establish a robust methodology to categorize whether or not a household is being food secure and food insecure by machine learning algorithms. In this study, we have used ten machine learning algorithms to classify the food security status of the Household. Gradient Boosting (GB), Random Forest (RF), Extra Tree (ET), Bagging, K-Nearest Neighbor (KNN), Decision Tree (DT), Support Vector Machine (SVM), Logistic Regression (LR), Ada Boost (AB) and Naive Bayes were the classification algorithms used throughout this study (NB). Then, we perform classification tasks from developing data set for household food security status by gathering data from HICE survey data and validating it by Domain Experts. The performance of all classifiers has better results for all performance metrics. The performance of the Random Forest and Gradient Boosting models are outstanding with a testing accuracy of 0.9997 and the other classifier such as Bagging, Decision tree, Ada Boost, Extra tree, K-nearest neighbor, Logistic Regression, SVM and Naive Bayes are scored 0.9996, 0.09996, 0.9994, 0.95675, 0.9415, 0.8915, 0.7853 and 0.7595, respectively.
Complete Machine Learning & Data Science with Python
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Supervised Learning -- K Nearest Neighbors Algorithm (KNN)
This article explains one of the simplest machine learning algorithm K Nearest Neighbors(KNN). KNN classifier and KNN regression are explained with examples in this article. K nearest neighbors algorithm basically predicts on the principle that the data is in the same class as the nearest data. According to name of the algorithm, "nearest neighbors" represents the closest data and "k" represents how many closest data is chosen. K value is a hyper parameter so it is tuned by the user and each trial usually gives different results.