40,754 research outputs found
A Novel Method for the Absolute Pose Problem with Pairwise Constraints
Absolute pose estimation is a fundamental problem in computer vision, and it
is a typical parameter estimation problem, meaning that efforts to solve it
will always suffer from outlier-contaminated data. Conventionally, for a fixed
dimensionality d and the number of measurements N, a robust estimation problem
cannot be solved faster than O(N^d). Furthermore, it is almost impossible to
remove d from the exponent of the runtime of a globally optimal algorithm.
However, absolute pose estimation is a geometric parameter estimation problem,
and thus has special constraints. In this paper, we consider pairwise
constraints and propose a globally optimal algorithm for solving the absolute
pose estimation problem. The proposed algorithm has a linear complexity in the
number of correspondences at a given outlier ratio. Concretely, we first
decouple the rotation and the translation subproblems by utilizing the pairwise
constraints, and then we solve the rotation subproblem using the
branch-and-bound algorithm. Lastly, we estimate the translation based on the
known rotation by using another branch-and-bound algorithm. The advantages of
our method are demonstrated via thorough testing on both synthetic and
real-world dataComment: 10 pages, 7figure
Splitting hybrid Make-To-Order and Make-To-Stock demand profiles
In this paper a demand time series is analysed to support Make-To-Stock (MTS)
and Make-To-Order (MTO) production decisions. Using a purely MTS production
strategy based on the given demand can lead to unnecessarily high inventory
levels thus it is necessary to identify likely MTO episodes.
This research proposes a novel outlier detection algorithm based on special
density measures. We divide the time series' histogram into three clusters. One
with frequent-low volume covers MTS items whilst a second accounts for high
volumes which is dedicated to MTO items. The third cluster resides between the
previous two with its elements being assigned to either the MTO or MTS class.
The algorithm can be applied to a variety of time series such as stationary and
non-stationary ones.
We use empirical data from manufacturing to study the extent of inventory
savings. The percentage of MTO items is reflected in the inventory savings
which were shown to be an average of 18.1%.Comment: demand analysis; time series; outlier detection; production strategy;
Make-To-Order(MTO); Make-To-Stock(MTS); 15 pages, 9 figure
A reasonable benchmarking frontier using DEA : an incentive scheme to improve efficiency in public hospitals
There exists research relating management concepts with productivity measurement methods that
offers useful solutions for improving management control in the public sector. Within this sphere,
we connect agency theory with efficiency analysis and describe how to define an incentives
scheme that can be applied in the public sector to monitor the efficiency and productivity of
managers. To fulfill the main objective of this research, we propose an iterative process for
determining what we define as a ‘reasonable frontier’, a concept that provides the foundation
required to establish the incentive scheme for the managers. Our ‘reasonable frontier’ has the
following properties: i) it detects the presence of outliers, ii) it proposes a procedure to establish
the influence introduced by extreme observations, and iii) it sorts out the problem of data masking.
The proposed method is applied to a sample of hospitals taken from the public network of the
Spanish health service. The results obtained confirm the applicability of the proposal made.
Summing up, we define and apply a useful method, combining aspects of agency theory and
efficiency analysis, which is of interest to those public authorities trying to design effective
incentive schemes which influence the decision making of the public managers
CleanNet: Transfer Learning for Scalable Image Classifier Training with Label Noise
In this paper, we study the problem of learning image classification models
with label noise. Existing approaches depending on human supervision are
generally not scalable as manually identifying correct or incorrect labels is
time-consuming, whereas approaches not relying on human supervision are
scalable but less effective. To reduce the amount of human supervision for
label noise cleaning, we introduce CleanNet, a joint neural embedding network,
which only requires a fraction of the classes being manually verified to
provide the knowledge of label noise that can be transferred to other classes.
We further integrate CleanNet and conventional convolutional neural network
classifier into one framework for image classification learning. We demonstrate
the effectiveness of the proposed algorithm on both of the label noise
detection task and the image classification on noisy data task on several
large-scale datasets. Experimental results show that CleanNet can reduce label
noise detection error rate on held-out classes where no human supervision
available by 41.5% compared to current weakly supervised methods. It also
achieves 47% of the performance gain of verifying all images with only 3.2%
images verified on an image classification task. Source code and dataset will
be available at kuanghuei.github.io/CleanNetProject.Comment: Accepted to CVPR 201
Watch and Learn: Semi-Supervised Learning of Object Detectors from Videos
We present a semi-supervised approach that localizes multiple unknown object
instances in long videos. We start with a handful of labeled boxes and
iteratively learn and label hundreds of thousands of object instances. We
propose criteria for reliable object detection and tracking for constraining
the semi-supervised learning process and minimizing semantic drift. Our
approach does not assume exhaustive labeling of each object instance in any
single frame, or any explicit annotation of negative data. Working in such a
generic setting allow us to tackle multiple object instances in video, many of
which are static. In contrast, existing approaches either do not consider
multiple object instances per video, or rely heavily on the motion of the
objects present. The experiments demonstrate the effectiveness of our approach
by evaluating the automatically labeled data on a variety of metrics like
quality, coverage (recall), diversity, and relevance to training an object
detector.Comment: To appear in CVPR 201
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