MATH_6: Eigenvalues and Eigenvectors.

date_range 05/03/2020 15:25

1. Definition:

• If $A$ is an $n\times n$ matrix, do nonzero vectors x in $R^n$ exist such that $A$x is a scalar multiple of x? The scalar, denoted by $\lambda$, is called an eigenvalue of matrix $A$, and nonzero vector x is called an eigenvector of $A$ corresponding to $\lambda$. So we have: $A$x$=$$\lambda$x.

  Let $A$ be an $n\times n$ matrix. The scalar $\lambda$ is called an eigenvalue of $A$ if there is a nonzero vector x such that $A$x$=$$\lambda$x. The vector x is called an eigenvector of $A$ corresponding to $\lambda$.

  • Note: x and $\lambda$ cannot be zero.

MATH_5: Khoảng tin cậy trong thống kê.

date_range 01/03/2020 04:39

0. Phân phối Student

• Bạn đọc nên xem trước bài MATH_4: Một số phân phối liên tục.

CV_3: Image Sharpening.

date_range 29/02/2020 08:12

1. Introduction

• Sharpending highlights transition in intensity. This technical uses in electronic printing and medical imaging. As we know, smoothing filters make output image could be accomplished in the spatial domain by pixel averaging in a neighborhood, it make the range of edges pixels and around pixels smaller. It that mean derivative at that point decreases. Thus, image differentiation enhances edges, noise and de-emphasizes with slowly varying intensities.

2. Foundation

• Next, we will discuss about first- and second- derivatives. There are various ways to define them. However, we require some properties in there:
  • First-derivative:
    • Must be zero in areas of constant intensity.
    • Must be non zero at onset of an intensity step or ramp.
    • Must be nonzero along intensity ramps.

PAPER_READER_2: Fast R-CNN - P2: Kiến trúc mạng và training.

date_range 28/02/2020 15:19

​ Bài viết dựa trên nội dung paper Fast R-CNN (Ross Girshick).

OTHER_1: Vấn đề nội dung mạng xã hội của ứng viên tìm việc.

date_range 27/02/2020 13:17

​ Bài viết dựa trên bài viết gốc Social media content matters for job candidates.