Parent and Child Node - The node which get divided into several sub-node is parent node and the sub-node formed is called child node. Parent and Child Node - The node which get divided into several sub-node is parent node and the sub-node formed is called child node. Subtree /Branch - If a subnode again split into further subnodes that entire part is called subtree (one Parent - Child part).It is a part of entire tree. Subtree /Branch - If a subnode again split into further subnodes that entire part is called subtree (one Parent - Child part).It is a part of entire tree. Decision Node - If a subnode split into further subnodes Then that splitted subnode is called decision node.

Various model-based diagnosis scenarios require the computation of most preferred fault explanations. Existing algorithms that are sound (i.e., output only actual fault explanations) and complete (i.e., can return all explanations), however, require exponential space to achieve this task. As a remedy, we propose two novel diagnostic search algorithms, called RBF-HS (Recursive Best-First Hitting Set Search) and HBF-HS (Hybrid Best-First Hitting Set Search), which build upon tried and tested techniques from the heuristic search domain. RBF-HS can enumerate an arbitrary predefined finite number of fault explanations in best-first order within linear space bounds, without sacrificing the desirable soundness or completeness properties. The idea of HBF-HS is to find a trade-off between runtime optimization and a restricted space consumption that does not exceed the available memory. In extensive experiments on real-world diagnosis cases we compared our approaches to Reiter's HS-Tree, a state-of-the-art method that gives the same theoretical guarantees and is as general(ly applicable) as the suggested algorithms. For the computation of minimum-cardinality fault explanations, we find that (1) RBF-HS reduces memory requirements substantially in most cases by up to several orders of magnitude, (2) in more than a third of the cases, both memory savings and runtime savings are achieved, and (3) given the runtime overhead is significant, using HBF-HS instead of RBF-HS reduces the runtime to values comparable with HS-Tree while keeping the used memory reasonably bounded. When computing most probable fault explanations, we observe that RBF-HS tends to trade memory savings more or less one-to-one for runtime overheads. Again, HBF-HS proves to be a reasonable remedy to cut down the runtime while complying with practicable memory bounds.

Experts fear the U.S. will see thousands more cancer deaths in the coming years due to delayed screenings, treatments and trials; Dr. Marc Siegel reacts. Throat cancer is a term that can apply to several different types of cancers that occur in different locations in the head and neck. In 2018, more than 30,000 people in the U.S. received a throat cancer diagnosis of some kind, according to MD Anderson Cancer Center. Both laryngeal and hypopharyngeal cancers start in the lower part of the throat. Patients diagnosed with laryngeal cancer mean that the disease was detected in an area affecting the voice box, including the supraglottis, which is located above the vocal cords, the glottis, which contains the vocal cords or the subglottis, which is below the vocal cords, according to the American Cancer Society.

Software often produces biased outputs. In particular, machine learning (ML) based software are known to produce erroneous predictions when processing discriminatory inputs. Such unfair program behavior can be caused by societal bias. In the last few years, Amazon, Microsoft and Google have provided software services that produce unfair outputs, mostly due to societal bias (e.g. gender or race). In such events, developers are saddled with the task of conducting fairness testing. Fairness testing is challenging; developers are tasked with generating discriminatory inputs that reveal and explain biases. We propose a grammar-based fairness testing approach (called ASTRAEA) which leverages context-free grammars to generate discriminatory inputs that reveal fairness violations in software systems. Using probabilistic grammars, ASTRAEA also provides fault diagnosis by isolating the cause of observed software bias. ASTRAEA's diagnoses facilitate the improvement of ML fairness. ASTRAEA was evaluated on 18 software systems that provide three major natural language processing (NLP) services. In our evaluation, ASTRAEA generated fairness violations with a rate of ~18%. ASTRAEA generated over 573K discriminatory test cases and found over 102K fairness violations. Furthermore, ASTRAEA improves software fairness by ~76%, via model-retraining.

This article was published as a part of the Data Science Blogathon. Decision Tree is one of the most intuitive and effective tools present in a Data Scientist's toolkit. It has an inverted tree-like structure that was once used only in Decision Analysis but is now a brilliant Machine Learning Algorithm as well, especially when we have a Classification problem on our hands. These decision trees are well-known for their capability to capture the patterns in the data. But, excess of anything is harmful, right?

A decision tree is a non-parametric supervised machine learning algorithm. It is extremely useful in classifying or labels the object. It works for both categorical and continuous datasets. It is like a tree structure in which the root node and its child node should be present. It has a child node that denotes a feature of the dataset. Prediction can be made with a leaf or terminal node.

We study the problem of balancing effectiveness and efficiency in automated feature selection. After exploring many feature selection methods, we observe a computational dilemma: 1) traditional feature selection is mostly efficient, but difficult to identify the best subset; 2) the emerging reinforced feature selection automatically navigates to the best subset, but is usually inefficient. Can we bridge the gap between effectiveness and efficiency under automation? Motivated by this dilemma, we aim to develop a novel feature space navigation method. In our preliminary work, we leveraged interactive reinforcement learning to accelerate feature selection by external trainer-agent interaction. In this journal version, we propose a novel interactive and closed-loop architecture to simultaneously model interactive reinforcement learning (IRL) and decision tree feedback (DTF). Specifically, IRL is to create an interactive feature selection loop and DTF is to feed structured feature knowledge back to the loop. First, the tree-structured feature hierarchy from decision tree is leveraged to improve state representation. In particular, we represent the selected feature subset as an undirected graph of feature-feature correlations and a directed tree of decision features. We propose a new embedding method capable of empowering graph convolutional network to jointly learn state representation from both the graph and the tree. Second, the tree-structured feature hierarchy is exploited to develop a new reward scheme. In particular, we personalize reward assignment of agents based on decision tree feature importance. In addition, observing agents' actions can be feedback, we devise another reward scheme, to weigh and assign reward based on the feature selected frequency ratio in historical action records. Finally, we present extensive experiments on real-world datasets to show the improved performance.

This story will introduce yet another implementation of Decision Trees, which I wrote as part of my thesis. Firstly, I will try to motivate why I have decided to take my time to come up with an own implementation of Decision Trees; I will list some of its features but also will list the disadvantages of the current implementation. Secondly, I will guide you through the basic usage of HDTree using code snippets and explaining some details along the way. Lastly, there will be some hints on how to customize and extend the HDTree with your own chunks of ideas. However, this article will not guide you through all of the basics of Decision Trees. There are really plenty of resources out there [1][2][3][16].

Mislabeled samples are ubiquitous in real-world datasets as rule-based or expert labeling is usually based on incorrect assumptions or subject to biased opinions. Neural networks can "memorize" these mislabeled samples and, as a result, exhibit poor generalization. This poses a critical issue in fault detection applications, where not only the training but also the validation datasets are prone to contain mislabeled samples. In this work, we propose a novel two-step framework for robust training with label noise. In the first step, we identify outliers (including the mislabeled samples) based on the update in the hypothesis space. In the second step, we propose different approaches to modifying the training data based on the identified outliers and a data augmentation technique. Contrary to previous approaches, we aim at finding a robust solution that is suitable for real-world applications, such as fault detection, where no clean, "noise-free" validation dataset is available. Under an approximate assumption about the upper limit of the label noise, we significantly improve the generalization ability of the model trained under massive label noise.

New research finds that causal machine learning models are not only more accurate than previous AI-based symptom checkers for patient diagnosis but, in many cases, can now exceed the diagnosis accuracy of human doctors. That's mainly due to the methods used, which allow for a more "outside the box" creativity in diagnosis, and even more improved accuracy for more complex patient illness. In the peer-reviewed study, authored by researchers from Babylon Health and University College London, the new model scored higher than 72% of general practitioner doctors when tasked with diagnosing written test cases of realistic illnesses. Up until now, and despite significant research efforts, the report claims, diagnostic algorithms have struggled to achieve the diagnosis accuracy of doctors. That's because machine learning algorithms have attempted to follow the same process as doctors in symptom checking.