A new weighted approach to imbalanced data classification problem via support vector machine with quadratic cost function

In this paper, a new weighted approach on Lagrangian support vector machine for imbalanced data classification problem is proposed. The weight parameters are embedded in the Lagrangian SVM formulation. The training method for weighted Lagrangian SVM is presented and its convergence is proven. The weighted Lagrangian SVM classifier is tested and compared with some other SVMs using synthetic and real data to show its effectiveness and feasibility.     

Personalized top-k skyline queries in high-dimensional space

As data of an unprecedented scale are becoming accessible, it becomes more and more important to help each user identify the ideal results of a manageable size. As such a mechanism, skyline queries have recently attracted a lot of attention for its intuitive query formulation. This intuitiveness, however, has a side effect of retrieving too many results, especially for high-dimensional data. This paper is to support personalized skyline queries as identifying “truly interesting” objects based on user-specific preference and retrieval size k. In particular, we abstract personalized skyline ranking as a dynamic search over skyline subspaces guided by user-specific preference. We then develop a novel algorithm navigating on a compressed structure itself, to reduce the storage overhead. Furthermore, we also develop novel techniques to interleave cube construction with navigation for some scenarios without a priori structure. Finally, we extend the proposed techniques for user-specific preferences including equivalence preference. Our extensive evaluation results validate the effectiveness and efficiency of the proposed algorithms on both real-life and synthetic data.     

An auto-scoring mechanism for evaluating problem-solving ability in a web-based learning environment

The rapid development of computer and network technologies has attracted researchers to investigate strategies for and the effects of applying information technologies in learning activities; simultaneously, learning environments have been developed to record the learning portfolios of students seeking web information for problem-solving. Although previous research has demonstrated the benefits of applying information technologies to learning activities, the difficulties in doing so have also been revealed. One of the major difficulties is the lack of a mechanism to assist teachers in evaluating the problem-solving ability of the students, such that constructive suggestions can be given to the students, and tutoring strategies can be improved accordingly.     

Influence of smartphone use styles on typing performance and biomechanical exposure

Twenty-seven subjects completed 2-min typing tasks using four typing styles: right-hand holding/typing (S-thumb) and two-hand typing at three heights (B-low, B-mid and B-high). The styles had significant effects on typing performance, neck and elbow flexion and muscle activities of the right trapezius and several muscles of the right upper limb (p < 0.0001 by repeated-measure analysis of variance). The subjects typed the fewest words (error-adjusted characters per minute: 78) with the S-thumb style. S-thumb style resulted in similar flexion angles of the neck, elbow and wrist, but significantly increased muscle activities in all tested muscles compared with the B-mid style. Holding the phone high or low reduced the flexion angles of the neck and right elbow compared with the B-mid style, but the former styles increased the muscle activity of the right trapezius. Right-hand holding/typing was not a preferable posture due to high muscle activities and slow typing speed.

Practitioner Summary: Right-hand holding/typing was not favoured, due to increased muscle activities and slower typing speed. Holding the phone high or low reduced the flexion angles of the neck and right elbow, but the former styles increased the muscle activity of the right trapezius compared with holding the phone at chest level.     

The role of goal awareness and information technology self-efficacy on job satisfaction of healthcare system users

This paper investigates the influence of goal awareness and IT self-efficacy on job satisfaction based on the motivation sequence model, goal-setting theory, and social cognitive theory. Using a large-scale field survey of healthcare enterprise resource planning (ERP) system users (n?=?352), this study investigates these relationships and provides important insight to healthcare ERP system researchers and managers. Both goal awareness and IT self-efficacy influence positive job satisfaction of healthcare ERP system users, as expected. Furthermore, the influence of goal awareness is stronger when the role of ERP systems is highly perceived for decision-making of the job. There was no interaction effect between goal awareness and IT self-efficacy in the post hoc analysis. The model is significantly supported by the empirical test with the large number of field data from healthcare ERP system users in the healthcare company. Practical and academic implications are discussed in the paper.     

Balancing of humanoid robot using contact force/moment control by task-oriented whole body control framework

Balancing control of humanoid robots is of great importance since it is a necessary functionality not only for maintaining a certain position without falling, but also for walking and running. For position controlled robots, the for-ce/torque sensors at each foot are utilized to measure the contact forces and moments, and these values are used to compute the joint angles to be commanded for balancing. The proposed approach in this paper is to maintain balance of torque-controlled robots by controlling contact force and moment using whole-body control framework with hierarchical structure. The control of contact force and moment is achieved by exploiting the full dynamics of the robot and the null-space motion in this control framework. This control approach enables compliant balancing behavior. In addition, in the case of double support phase, required contact force and moment are controlled using the redundancy in the contact force and moment space. These algorithms are implemented on a humanoid legged robot and the experimental results demonstrate the effectiveness of them.     

An SNS-based model for finding collaborative partners

This paper proposes a model, Recommendation of Appropriate Partners (RAP), used on a Social Networking Service (SNS) for locating appropriate “helpers” for users based on individual users’ Chain of Friends (CoF) relationships. Using the RAP model, individual users can participate in a collaborative online community in remote locations, whereby helpers are willing to help other users solve their tasks/problems, and it is intended that both the users and helpers gain knowledge from these interactive online sessions. An example of the RAP-based system was implemented to invite Program Committee members to an international conference. The system was evaluated and the experimental results show that our model is very effective for discovering collaboration partners and finding users with similar interests in order to create communities for providing future and longer-term helping exchange.

     

Effect of plasma chemistry on the simulation of helium atmospheric-pressure plasmas

The effect on the selection of different plasma chemistries for simulating a typical dielectric barrier discharge (DBD) driven by quasi-pulsed power source (20 kHz) is investigated. The numerical simulation was performed by using the one-dimensional self-consistent fluid modeling solver. Our simulation result indicates that the computed temporal current density can be significantly improved by using a complex version of plasma chemistry module rather than the simple one and demonstrates an excellent agreement with the experimental data. The result suggests the metastable, excited and ionic helium related reaction channels, which are important in simulating a DBD, should be taken into account. Furthermore, it also reveals that the power absorption of ions is considerably higher than that of the electron.     

Step-by-step improvement of MPS method in simulating violent free-surface motions and impact-loads

The violent free-surface motions and the corresponding impact loads are numerically simulated by using the Moving Particle Semi-implicit (MPS) method, which was originally proposed by Koshizuka and Oka [10] for incompressible flows. In the original MPS method, there were several defects including non-optimal source term, gradient and collision models, and search of free-surface particles, which led to less-accurate fluid motions and non-physical pressure fluctuations. In the present study, how those defects can be remedied is illustrated by step-by-step improvements in the respective processes of the revised MPS method. For illustration, two examples are studied; (i) dam breaking problem and (ii) liquid sloshing inside a rectangular tank. The improvement of each step is explained and numerically demonstrated. The numerical results are also compared against the experimental results of Martin and Moyce [12] for dam-breaking problem and Kishev et al. [9] for sloshing problem. The numerical results for violent free-surface motions and impact pressures are in good agreement with their experimental data.     

A real-time interactive virtual classroom multimedia distancelearning system

In this paper, we present the design and development of a real-time interactive virtual classroom multimedia distance learning system at the University of Washington. There has been rapid progress in digital media compression research, and the delivery of media data on the public Internet is becoming widespread. A real-time interactive virtual classroom allows a remote participant to not only receive a live class feed, but also to interact in a live class by asking questions with audio, video in real-time using an Internet connection. Many instructors use electronically prepared slides during their class. The traditional video coding algorithms are not able to compress this slide data very well at low bit-rates. We propose a Web-based real-time presentation system for the electronic slides. Instructors also write text on a white board or a piece of paper during the class. At low bit-rates, conventional video encoding algorithms cannot encode this handwritten text video with enough fidelity, resulting in an illegible decoded video. We propose an extension of the well known bilevel image encoding algorithms to handle the handwritten text video. Our method results in decoded video frames which can be read very clearly when encoded at low bit-rates. We have developed a set of tools which allows recording the live classroom session and automatic creation of a synchronized multimedia integration language (SMIL) presentation, which can be used for a later viewing