Performance Analysis
Extrapolating Expected Accuracies for Large Multi-Class Problems
Zheng, Charles, Achanta, Rakesh, Benjamini, Yuval
Many machine learning tasks are interested in recognizing or identifying an individual instance within a large set of possible candidates. These problems are usually modeled as multi-class classification problems, with a large and possibly complex label set. Leading examples include detecting the speaker from his voice patterns (Togneri and Pullella, 2011), identifying the author from her written text (Stamatatos et al., 2014), or labeling the object category from its image (Duygulu et al., 2002, Deng et al., 2010, Oquab et al., 2014). In all these examples, the algorithm observes an input x, and uses the classifier function h to guess the label y from a large label set S. 1 There are multiple practical challenges in developing classifiers for large label sets. Collecting high quality training data is perhaps the main obstacle, as the costs scale with the number of classes. It can be affordable to first collect data for a small set of classes, even if the long-term goal is to generalize to a larger set. Furthermore, classifier development can be accelerated by training first on fewer classes, as each training cycle may require substantially less resources. Indeed, due to interest in how small-set performance generalizes to larger sets, such comparisons can found in the literature (Oquab et al., 2014, Griffin et al., 2007). A natural question is: how does changing the size of the label set affect the classification accuracy?
More Data Mining with R Udemy
In data mining and association rule learning, lift is a measure of the performance of a targeting model (association rule) at predicting or classifying cases as having an enhanced response (with respect to the population as a whole), measured against a random choice targeting model. A targeting model is doing a good job if the response within the target is much better than the average for the population as a whole. Lift is simply the ratio of these values: target response divided by average response. For example, suppose a population has an average response rate of 5%, but a certain model (or rule) has identified a segment with a response rate of 20%. Then that segment would have a lift of 4.0 (20%/5%).
[P] Melanoma detection model (http://melanoma.modelderm.com) โข r/MachineLearning
I made a melanoma diagnosis model named "Model Melanoma" based on deep learning algorithm (http://melanoma.modelderm.com). ResNet152 and VGG19 were used as a CNN model, around 300,000 images (179 classes) were used as a training dataset. For reference, the skin cancer detection model published on nature showed 0.96 with 225 melanocytic (58 malignant, 167 benign) test images of the Edinburgh dermofit library. The web-based test platform provides the miss rate or false negative rate (1-sensitivity) in the diagnosis of melanoma. In addition, we made 176 skin diseases diagnosis model (http://modelderm.com)
Data Science with Python: Exploratory Analysis with Movie-Ratings and Fraud Detection with Credit-Card Transactions
The following problems are taken from the projects / assignments in the edX course Python for Data Science and the coursera course Applied Machine Learning in Python (UMich). The IMDB Movie Dataset (MovieLens 20M) is used for the analysis. The dataset is downloaded from here . This dataset contains 20 million ratings and 465,000 tag applications applied to 27,000 movies by 138,000 users and was released in 4/2015. Understand the trend in average ratings for different movie genres over years (from 1995 to 2015) and Correlation between the trends for different genres (8 different genres are considered: Animation, Comedy, Romance, Thriller, Horror, Sci-Fi and Musical).
A Real-Time Autonomous Highway Accident Detection Model Based on Big Data Processing and Computational Intelligence
Ozbayoglu, A. Murat, Kucukayan, Gokhan, Dogdu, Erdogan
Due to increasing urban population and growing number of motor vehicles, traffic congestion is becoming a major problem of the 21st century. One of the main reasons behind traffic congestion is accidents which can not only result in casualties and losses for the participants, but also in wasted and lost time for the others that are stuck behind the wheels. Early detection of an accident can save lives, provides quicker road openings, hence decreases wasted time and resources, and increases efficiency. In this study, we propose a preliminary real-time autonomous accident-detection system based on computational intelligence techniques. Istanbul City traffic-flow data for the year 2015 from various sensor locations are populated using big data processing methodologies. The extracted features are then fed into a nearest neighbor model, a regression tree, and a feed-forward neural network model. For the output, the possibility of an occurrence of an accident is predicted. The results indicate that even though the number of false alarms dominates the real accident cases, the system can still provide useful information that can be used for status verification and early reaction to possible accidents.
AWS raises machine learning expectations for cloud security
Turning on machine-learning based cloud security tools like Amazon Web Service's (AWS) new GuardDuty and Macie offerings might be a no-brainer for AWS customers. It raises the bar for attackers, but will not protect you from sophisticated adversaries, experts say. The AWS Macie service, announced in August, trains on the content of users' Amazon S3 buckets and alerts customers when it detects suspicious activity, with a focus on PCI, HIPAA, and GDPR compliance. AWS GuardDuty, a complementary offering announced at the end of November, uses machine learning to analyze AWS CloudTrail, VPC Flow Logs, and AWS DNS logs. Like Macie, GuardDuty focuses on anomaly detection to alert customers to suspicious activity.
Iterative Random Forests to detect predictive and stable high-order interactions
Basu, Sumanta, Kumbier, Karl, Brown, James B., Yu, Bin
Genomics has revolutionized biology, enabling the interrogation of whole transcriptomes, genome-wide binding sites for proteins, and many other molecular processes. However, individual genomic assays measure elements that interact in vivo as components of larger molecular machines. Understanding how these high-order interactions drive gene expression presents a substantial statistical challenge. Building on Random Forests (RF), Random Intersection Trees (RITs), and through extensive, biologically inspired simulations, we developed the iterative Random Forest algorithm (iRF). iRF trains a feature-weighted ensemble of decision trees to detect stable, high-order interactions with same order of computational cost as RF. We demonstrate the utility of iRF for high-order interaction discovery in two prediction problems: enhancer activity in the early Drosophila embryo and alternative splicing of primary transcripts in human derived cell lines. In Drosophila, among the 20 pairwise transcription factor interactions iRF identifies as stable (returned in more than half of bootstrap replicates), 80% have been previously reported as physical interactions. Moreover, novel third-order interactions, e.g. between Zelda (Zld), Giant (Gt), and Twist (Twi), suggest high-order relationships that are candidates for follow-up experiments. In human-derived cells, iRF re-discovered a central role of H3K36me3 in chromatin-mediated splicing regulation, and identified novel 5th and 6th order interactions, indicative of multi-valent nucleosomes with specific roles in splicing regulation. By decoupling the order of interactions from the computational cost of identification, iRF opens new avenues of inquiry into the molecular mechanisms underlying genome biology.
Build your own Antivirus In 5 minutes using Machine Learning
To build our first antivirus, we need to know about the virus first. Every antivirus program needs to constantly update their database to defend against new virus thread. Day by day not only our security systems are getting smarter but the viruses as well. Let's see some example of viruses - Polymorphic virus - This type of virus is hard to detect because this virus changes its signature every time it creates a replica. Antivirus software takes more than days to detect this virus type.
Cross-Validation with Confidence
Cross-validation is one of the most popular model selection methods in statistics and machine learning. Despite its wide applicability, traditional cross validation methods tend to select overfitting models, due to the ignorance of the uncertainty in the testing sample. We develop a new, statistically principled inference tool based on cross-validation that takes into account the uncertainty in the testing sample. This new method outputs a set of highly competitive candidate models containing the best one with guaranteed probability. As a consequence, our method can achieve consistent variable selection in a classical linear regression setting, for which existing cross-validation methods require unconventional split ratios. When used for regularizing tuning parameter selection, the method can provide a further trade-off between prediction accuracy and model interpretability. We demonstrate the performance of the proposed method in several simulated and real data examples.