711,242 research outputs found
Sparse Bilinear Logistic Regression
In this paper, we introduce the concept of sparse bilinear logistic
regression for decision problems involving explanatory variables that are
two-dimensional matrices. Such problems are common in computer vision,
brain-computer interfaces, style/content factorization, and parallel factor
analysis. The underlying optimization problem is bi-convex; we study its
solution and develop an efficient algorithm based on block coordinate descent.
We provide a theoretical guarantee for global convergence and estimate the
asymptotical convergence rate using the Kurdyka-{\L}ojasiewicz inequality. A
range of experiments with simulated and real data demonstrate that sparse
bilinear logistic regression outperforms current techniques in several
important applications.Comment: 27 pages, 5 figure
Model selection in logistic regression
This paper is devoted to model selection in logistic regression. We extend
the model selection principle introduced by Birg\'e and Massart (2001) to
logistic regression model. This selection is done by using penalized maximum
likelihood criteria. We propose in this context a completely data-driven
criteria based on the slope heuristics. We prove non asymptotic oracle
inequalities for selected estimators. Theoretical results are illustrated
through simulation studies
Structured Learning via Logistic Regression
A successful approach to structured learning is to write the learning
objective as a joint function of linear parameters and inference messages, and
iterate between updates to each. This paper observes that if the inference
problem is "smoothed" through the addition of entropy terms, for fixed
messages, the learning objective reduces to a traditional (non-structured)
logistic regression problem with respect to parameters. In these logistic
regression problems, each training example has a bias term determined by the
current set of messages. Based on this insight, the structured energy function
can be extended from linear factors to any function class where an "oracle"
exists to minimize a logistic loss.Comment: Advances in Neural Information Processing Systems 201
Expectation-maximization for logistic regression
We present a family of expectation-maximization (EM) algorithms for binary
and negative-binomial logistic regression, drawing a sharp connection with the
variational-Bayes algorithm of Jaakkola and Jordan (2000). Indeed, our results
allow a version of this variational-Bayes approach to be re-interpreted as a
true EM algorithm. We study several interesting features of the algorithm, and
of this previously unrecognized connection with variational Bayes. We also
generalize the approach to sparsity-promoting priors, and to an online method
whose convergence properties are easily established. This latter method
compares favorably with stochastic-gradient descent in situations with marked
collinearity
Resampling Logistic Regression Untuk Penanganan Ketidakseimbangan Class Pada Prediksi Cacat Software
Software yang berkualitas tinggi adalah software yang dapat membantu proses bisnis Perusahaan dengan efektif, efesien dan tidak ditemukan cacat selama proses pengujian, pemeriksaan, dan implementasi. Perbaikan software setelah pengirimana dan implementasi, membutuhkan biaya jauh lebih mahal dari pada saat pengembangan. Biaya yang dibutuhkan untuk pengujian software menghabisakan lebih dari 50% dari biaya pengembangan. Dibutuhkan model pengujian cacat software untuk mengurangi biaya yang dikeluarkan. Saat ini belum ada model prediksi cacat software yang berlaku umum pada saat digunakan digunakan. Model Logistic Regression merupakan model paling efektif dan efesien dalam prediksi cacat software. Kelemahan dari Logistic Regression adalah rentan terhadap underfitting pada dataset yang kelasnya tidak seimbang, sehingga akan menghasilkan akurasi yang rendah. Dataset NASA MDP adalah dataset umum yang digunakan dalam prediksi cacat software. Salah satu karakter dari dataset prediksi cacat software, termasuk didalamnya dataset NASA MDP adalah memiliki ketidakseimbangan pada kelas. Untuk menangani masalah ketidakseimbangan kelas pada dataset cacat software pada penelitian ini diusulkan metode resampling. Eksperimen dilakukan untuk membandingkan hasil kinerja Logistic Regression sebelum dan setelah diterapkan metode resampling. Demikian juga dilakukan eksperimen untuk membandingkan metode yang diusulkan hasil pengklasifikasi lain seperti Naïve Bayes, Linear Descriminant Analysis, C4.5, Random Forest, Neural Network, k-Nearest Network. Hasil eksperimen menunjukkan bahwa tingkat akurasi Logistic Regression dengan resampling lebih tinggi dibandingkan dengan metode Logistric Regression yang tidak menggunakan resampling, demikian juga bila dibandingkan dengan pengkalisifkasi yang lain. Dari hasil eksperimen di atas dapat disimpulkan bahwa metode resampling terbukti efektif dalam menyelesaikan ketidakseimbangan kelas pada prediksi cacat software dengan algoritma Logistic Regression
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