justin

Today I read a paper titled “Real-time Image-based 6-DOF Localization in Large-Scale Environments”

The abstract is:
We present a real-time approach for image-based localization within large scenes that have been reconstructed offline using structure from motion (Sfm).

From monocular video, our method continuously computes a precise 6-DOF camera pose, by efficiently tracking natural features and matching them to 3D points in the Sfm point cloud.

Our main contribution lies in efficiently interleaving a fast keypoint tracker that uses inexpensive binary feature descriptors with a new approach for direct 2D-to-3D matching.

The 2D-to-3D matching avoids the need for online extraction of scale-invariant features.

Instead, offline we construct an indexed database containing multiple DAISY descriptors per 3D point extracted at multiple scales.

The key to the efficiency of our method lies in invoking DAISY descriptor extraction and matching sparingly during localization, and in distributing this computation over a window of successive frames.

This enables the algorithm to run in real-time, without fluctuations in the latency over long durations.

We evaluate the method in large indoor and outdoor scenes.

Our algorithm runs at over 30 Hz on a laptop and at 12 Hz on a low-power, mobile computer suitable for onboard computation on a quadrotor micro aerial vehicle.

Today I read a paper titled “Weak ties: Subtle role of information diffusion in online social networks”

The abstract is:
As a social media, online social networks play a vital role in the social information diffusion.

However, due to its unique complexity, the mechanism of the diffusion in online social networks is different from the ones in other types of networks and remains unclear to us.

Meanwhile, few works have been done to reveal the coupled dynamics of both the structure and the diffusion of online social networks.

To this end, in this paper, we propose a model to investigate how the structure is coupled with the diffusion in online social networks from the view of weak ties.

Through numerical experiments on large-scale online social networks, we find that in contrast to some previous research results, selecting weak ties preferentially to republish cannot make the information diffuse quickly, while random selection can achieve this goal.

However, when we remove the weak ties gradually, the coverage of the information will drop sharply even in the case of random selection.

We also give a reasonable explanation for this by extra analysis and experiments.

Finally, we conclude that weak ties play a subtle role in the information diffusion in online social networks.

On one hand, they act as bridges to connect isolated local communities together and break through the local trapping of the information.

On the other hand, selecting them as preferential paths to republish cannot help the information spread further in the network.

As a result, weak ties might be of use in the control of the virus spread and the private information diffusion in real-world applications.

Today I read a paper titled “Non-photorealistic image rendering with a labyrinthine tiling”

The abstract is:
The paper describes a new image processing for a non-photorealistic rendering.

The algorithm is based on a random generation of gray tones and competing statistical requirements.

The gray tone value of each pixel in the starting image is replaced selecting among randomly generated tone values, according to the statistics of nearest-neighbor and next-nearest-neighbor pixels.

Two competing conditions for replacing the tone values – one position on the local mean value the other on the local variance – produce a peculiar pattern on the image.

This pattern has a labyrinthine tiling aspect.

For certain subjects, the pattern enhances the look of the image.

Today I read a paper titled “Making the road by searching – A search engine based on Swarm Information Foraging”

The abstract is:
Search engines are nowadays one of the most important entry points for Internet users and a central tool to solve most of their information needs.

Still, there exist a substantial amount of users’ searches which obtain unsatisfactory results.

Needless to say, several lines of research aim to increase the relevancy of the results users retrieve.

In this paper the authors frame this problem within the much broader (and older) one of information overload.

They argue that users’ dissatisfaction with search engines is a currently common manifestation of such a problem, and propose a different angle from which to tackle with it.

As it will be discussed, their approach shares goals with a current hot research topic (namely, learning to rank for information retrieval) but, unlike the techniques commonly applied in that field, their technique cannot be exactly considered machine learning and, additionally, it can be used to change the search engine’s response in real-time, driven by the users behavior.

Their proposal adapts concepts from Swarm Intelligence (in particular, Ant Algorithms) from an Information Foraging point of view.

It will be shown that the technique is not only feasible, but also an elegant solution to the stated problem; what’s more, it achieves promising results, both increasing the performance of a major search engine for informational queries, and substantially reducing the time users require to answer complex information needs.

Today I read a paper titled “Smart depth of field optimization applied to a robotised view camera”

The abstract is:
The great flexibility of a view camera allows to take high quality photographs that would not be possible any other way.

But making a given object into focus is a long and tedious task, although the underlying laws are well known.

This paper presents the result of a project which has lead to the design of a computer controlled view camera and to its companion software.

Thanks to the high precision machining of its components, and to the known optical parameters of lenses and sensor, we have been able to consider a reliable mathematical model of the view camera, allowing the acquisition of 3D coordinates to build a geometrical model of the object.

Then many problems can be solved, e.g.

minimizing the f-number while maintaining the object within the depth of field, which takes the form of a constrained optimization problem.

All optimization algorithms have been validated on a virtual view camera before implementation on the prototype .

Today I read a paper titled “From Playability to a Hierarchical Game Usability Model”

The abstract is:
This paper presents a brief review of current game usability models.

This leads to the conception of a high-level game development-centered usability model that integrates current usability approaches in game industry and game research.

Today I read a paper titled “A Vision-based Computed Torque Control for Parallel Kinematic Machines”

The abstract is:
In this paper, a novel approach for parallel kinematic machine control relying on a fast exteroceptive measure is implemented and validated on the Orthoglide robot.

This approach begins with rewriting the robot models as a function of the only end-effector pose.

It is shown that such an operation reduces the model complexity.

Then, this approach uses a classical Cartesian space computed torque control with a fast exteroceptive measure, reducing the control schemes complexity.

Simulation results are given to show the expected performance improvements and experiments prove the practical feasibility of the approach.

Today I read a paper titled “Interaction With Tilting Gestures In Ubiquitous Environments”

The abstract is:
In this paper, we introduce a tilting interface that controls direction based applications in ubiquitous environments.

A tilt interface is useful for situations that require remote and quick interactions or that are executed in public spaces.

We explored the proposed tilting interface with different application types and classified the tilting interaction techniques.

Augmenting objects with sensors can potentially address the problem of the lack of intuitive and natural input devices in ubiquitous environments.

We have conducted an experiment to test the usability of the proposed tilting interface to compare it with conventional input devices and hand gestures.

The experiment results showed greater improvement of the tilt gestures in comparison with hand gestures in terms of speed, accuracy, and user satisfaction.

Today I read a paper titled “Enhanced Integrated Scoring for Cleaning Dirty Texts”

The abstract is:
An increasing number of approaches for ontology engineering from text are gearing towards the use of online sources such as company intranet and the World Wide Web.

Despite such rise, not much work can be found in aspects of preprocessing and cleaning dirty texts from online sources.

This paper presents an enhancement of an Integrated Scoring for Spelling error correction, Abbreviation expansion and Case restoration (ISSAC).

ISSAC is implemented as part of a text preprocessing phase in an ontology engineering system.

New evaluations performed on the enhanced ISSAC using 700 chat records reveal an improved accuracy of 98% as compared to 96.5% and 71% based on the use of only basic ISSAC and of Aspell, respectively.

Today I read a paper titled “Dynamic Feature Description in Human Action Recognition”

The abstract is:
This work aims to present novel description methods for human action recognition.

Generally, a video sequence can be represented as a collection of spatial temporal words by detecting space-time interest points and describing the unique features around the detected points (Bag of Words representation).

Interest points as well as the cuboids around them are considered informative for feature description in terms of both the structural distribution of interest points and the information content inside the cuboids.

Our proposed description approaches are based on this idea and making the feature descriptors more discriminative.

Today I read a paper titled “A framework of motion capture system based human behaviours simulation for ergonomic analysis”

The abstract is:
With the increasing of computer capabilities, Computer aided ergonomics (CAE) offers new possibilities to integrate conventional ergonomic knowledge and to develop new methods into the work design process.

As mentioned in [1], different approaches have been developed to enhance the efficiency of the ergonomic evaluation.

Ergonomic expert systems, ergonomic oriented information systems, numerical models of human, etc.

have been implemented in numerical ergonomic software.

Until now, there are ergonomic software tools available, such as Jack, Ergoman, Delmia Human, 3DSSPP, and Santos, etc.

[2-4].

The main functions of these tools are posture analysis and posture prediction.

In the visualization part, Jack and 3DSSPP produce results to visualize virtual human tasks in 3-dimensional, but without realistic physical properties.

Nowadays, with the development of computer technology, the simulation of physical world is paid more attention.

Physical engines [5] are used more and more in computer game (CG) field.

The advantage of physical engine is the nature physical world environment simulation.

The purpose of our research is to use the CG technology to create a virtual environment with physical properties for ergonomic analysis of virtual human.

Today I read a paper titled “Predicting Abnormal Returns From News Using Text Classification”

The abstract is:
We show how text from news articles can be used to predict intraday price movements of financial assets using support vector machines.

Multiple kernel learning is used to combine equity returns with text as predictive features to increase classification performance and we develop an analytic center cutting plane method to solve the kernel learning problem efficiently.

We observe that while the direction of returns is not predictable using either text or returns, their size is, with text features producing significantly better performance than historical returns alone.

Today I read a paper titled “Ubiquitous Positioning: A Taxonomy for Location Determination on Mobile Navigation System”

The abstract is:
The location determination in obstructed area can be very challenging especially if Global Positioning System are blocked.

Users will find it difficult to navigate directly on-site in such condition, especially indoor car park lot or obstructed environment.

Sometimes, it needs to combine with other sensors and positioning methods in order to determine the location with more intelligent, reliable and ubiquity.

By using ubiquitous positioning in mobile navigation system, it is a promising ubiquitous location technique in a mobile phone since as it is a familiar personal electronic device for many people.

However, as research on ubiquitous positioning systems goes beyond basic methods there is an increasing need for better comparison of proposed ubiquitous positioning systems.

System developers are also lacking of good frameworks for understanding different options during building ubiquitous positioning systems.

This paper proposes taxonomy to address both of these problems.

The proposed taxonomy has been constructed from a literature study of papers and articles on positioning estimation that can be used to determine location everywhere on mobile navigation system.

For researchers the taxonomy can also be used as an aid for scoping out future research in the area of ubiquitous positioning.

Today I read a paper titled “Morphing of Triangular Meshes in Shape Space”

The abstract is:
We present a novel approach to morph between two isometric poses of the same non-rigid object given as triangular meshes.

We model the morphs as linear interpolations in a suitable shape space $\mathcal{S}$.

For triangulated 3D polygons, we prove that interpolating linearly in this shape space corresponds to the most isometric morph in $\mathbb{R}^3$.

We then extend this shape space to arbitrary triangulations in 3D using a heuristic approach and show the practical use of the approach using experiments.

Furthermore, we discuss a modified shape space that is useful for isometric skeleton morphing.

All of the newly presented approaches solve the morphing problem without the need to solve a minimization problem.

Today I read a paper titled “Block-based quantum-logic synthesis”

The abstract is:
In this paper, the problem of constructing an efficient quantum circuit for the implementation of an arbitrary quantum computation is addressed.

To this end, a basic block based on the cosine-sine decomposition method is suggested which contains $l$ qubits.

In addition, a previously proposed quantum-logic synthesis method based on quantum Shannon decomposition is recursively applied to reach unitary gates over $l$ qubits.

Then, the basic block is used and some optimizations are applied to remove redundant gates.

It is shown that the exact value of $l$ affects the number of one-qubit and CNOT gates in the proposed method.

In comparison to the previous synthesis methods, the value of $l$ is examined consequently to improve either the number of CNOT gates or the total number of gates.

The proposed approach is further analyzed by considering the nearest neighbor limitation.

According to our evaluation, the number of CNOT gates is increased by at most a factor of $\frac{5}{3}$ if the nearest neighbor interaction is applied.

Today I read a paper titled “Real-time jam-session support system”

The abstract is:
We propose a method for the problem of real time chord accompaniment of improvised music.

Our implementation can learn an underlying structure of the musical performance and predict next chord.

The system uses Hidden Markov Model to find the most probable chord sequence for the played melody and then a Variable Order Markov Model is used to a) learn the structure (if any) and b) predict next chord.

We implemented our system in Java and MAX/Msp and compared and evaluated using objective (prediction accuracy) and subjective (questionnaire) evaluation methods.

Today I read a paper titled “Tales of 34 iPhone Users: How they change and why they are different”

The abstract is:
We present results from a longitudinal study of 34 iPh-one 3GS users, called LiveLab.

LiveLab collected unprecedented usage data through an in-device, programmable logger and several structured interviews with the participants throughout the study.

We have four objectives in writing this paper: (i) share the findings with the research community; (ii) provide insights guiding the design of smartphone systems and applications; (iii) demonstrate the power of prudently designed longitudinal field studies and the power of advanced research methods; and (iv) raise important questions that the research community can help answer in a collaborative, multidisciplinary manner.

We show how the smartphone usage changes over the year and why the users are different (and similar) in their usage.

In particular, our findings highlight application and web usage dynamics, the influence of socioeconomic status (SES) on usage, and the shortcomings of iPhone 3GS and its ecosystem.

We further show that distinct classes of usage patterns exist, and these classes are best served by different phone designs, instead of the one-size-fits-all phone Apple provides.

Our findings are significant not only for understanding smartphone users but also in guiding device and application development and optimizations.

While we present novel results that can only be produced by a study of this nature, we also raise new research questions to be investigated by the mobile research community.

Today I read a paper titled “Hubs and Clusters in the Evolving U. S. Internal Migration Network”

The abstract is:
Most nations of the world periodically publish N x N origin-destination tables, recording the number of people who lived in geographic subdivision i at time t and j at t+1.

We have developed and widely applied to such national tables and other analogous (weighted, directed) socioeconomic networks, a two-stage–double-standardization and (strong component) hierarchical clustering–procedure.

Previous applications of this methodology and related analytical issues are discussed.

Its use is illustrated in a large-scale study, employing recorded United States internal migration flows between the 3,000+ county-level units of the nation for the periods 1965-1970 and 1995-2000.

Prominent, important features–such as ”cosmopolitan hubs” and “functional regions”–are extracted from master dendrograms.

The extent to which such characteristics have varied over the intervening thirty years is evaluated.