Tremendous amounts of data are generated daily. Accordingly, unstructured text data that is distributed through news, blogs, and social media has gained much attention from many researchers as this data contains abundant information about various consumers' opinions. However, as the usefulness of text data is increasing, attempts to gain profits by distorting text data maliciously or non-maliciously are also increasing. In this sense, various types of spam detection techniques have been studied to prevent the side effects of spamming. The most representative studies include e-mail spam detection, web spam detection, and opinion spam detection. "Spam" is recognized on the basis of three characteristics and actions: (1) if a certain user is recognized as a spammer, then all content created by that user should be recognized as spam; (2) if certain content is exposed to other users (regardless of the users' intention), then content is recognized as spam; and (3) any content that contains malicious or non-malicious false information is recognized as spam. Many studies have been performed to solve type (1) and type (2) spamming by analyzing various metadata, such as user networks and spam words. In the case of type (3), however, relatively few studies have been conducted because it is difficult to determine the veracity of a certain word or information. In this study, we regard a hashtag that is irrelevant to the content of a blog post as spam and devise a methodology to detect such spam hashtags.

In this poster, we present an experiment that compares three forms of interaction to study the user behavior with regards to the effects of camera view for in-situ robot control. We compared three hand-held interfaces with: (1) no camera view (Nominal), (2) a camera view/aim is always fixed toward the robot (Fixed) and (3) a camera view with user controlled aim (Free). The three approaches represent different balances between information availability, interface accessibility and the amount of induced attentional shifts. Experiment results have shown that all three interaction models exhibited similar task performance even though the Fixed type induced much less attentional shifts. On the other hand, the users much preferred the Nominal and Free type. Users mostly ignored the camera view despite having to shift one's attention excessively, due to the lack of visual quality, realistic scale and depth information.

Participating in a play is one of integral curriculum for young children at nurseries and kindergartens. At the same time, it is not very easy to successfully run and manage a play for young children due to their low age and immaturity. Scripts are difficult to memorize and children's attention span is quite short. We are exploring the use of a robot and augmented reality (AR) technology to assist the nursery teachers in hopes to alleviate the difficult and complicated task of running the play, and also as a way to increase the learning effect by promoting the concentration and immersion (by the presence of the robot and novelty of the augmented display) [1, 2, 3]. For this purpose, we have devised a semi-autonomous remote-controlled projector robot with the capabilities of background projection and control, generating the synthesized augmented view, camera/movement control, producing story narration and various special effects. We have recently deployed the robot assistant for a play ('Three Little Pigs') at an actual nursery to observe and investigate various aspects of human robot interaction. For instance, the robot interacts with the actors on stage, leading and guiding them by showing (with small display on the robot) the synthesized augmented view, script guidance, and putting forth and changing the backdrop projection. It also assumes the role of the camera man and may instigate minute interplay with the actor as it zooms in and out on actors (by remote control). Our initial observation indicated that the use of the robot and AR indeed exhibited very high potential in drawing the attention of the children and enhancing the educational effect, but required the right amount of autonomy and external control and an intuitive interface.

Abstract This paper addresses performance issues on ARDA Metadata Grid Application (AMGA) and presents new techniques to improve the throughput of AMGA for the WISDOM environment. The first issue is a performance degradation problem when AMGA is used as a metadata service for task retrieval in the WISDOM environment. To deal with the issue, a new AMGA operation designed to reduce the communication overhead required to retrieve a task from AMGA is proposed. According to a performance study conducted with the new operation, the throughput of task retrieval using the proposed operation can be as much as 70 times higher than the throughput when using the existing AMGA operations. The second issue is an AMGA throughput issue in large‐scale grid‐enabled applications such as WISDOM, where it is not uncommon that thousands of jobs running on grid nodes access the AGMA service simultaneously. To address this issue, integration of a load‐balancing technique and a DB connection pool technique into the AMGA are proposed. Test results demonstrate that the performance can be improved linearly in proportion to the number of AMGA servers set up for load balancing; the performance improvement continues until the performance limit of the backend database system is reached. Copyright © 2009 John Wiley & Sons, Ltd.

Virtual studios have long been used in commercial broadcasting. However, most virtual studios are based on "blue screen" technology, and its two-dimensional (2-D) nature restricts the user from making natural three-dimensional (3-D) interactions. Actors have to follow prewritten scripts and pretend as if directly interacting with the synthetic objects. This often creates an unnatural and seemingly uncoordinated output. In this paper, we introduce an improved virtual-studio framework to enable actors/users to interact in 3-D more naturally with the synthetic environment and objects. The proposed system uses a stereo camera to first construct a 3-D environment (for the actor to act in), a multiview camera to extract the image and 3-D information about the actor, and a real-time registration and rendering software for generating the final output. Synthetic 3-D objects can be easily inserted and rendered, in real time, together with the 3-D environment and video actor for natural 3-D interaction. The enabling of natural 3-D interaction would make more cinematic techniques possible including live and spontaneous acting. The proposed system is not limited to broadcast production, but can also be used for creating virtual/augmented-reality environments for training and entertainment

In the future ubiquitous computing living environment, humans will interact with computers (knowingly or unknowingly) any where by various means other than through the traditional desktop interface (e.g. keyboard and mouse). Interacting with a "smart" table could very well be one such probable scenario. In this paper, we outline and classify various possible techniques for interacting with the smart table under reasonable assumptions about the operating environment. We considered the primitive tasks of object selection, object manipulation and menu control. The classification should serve as a basis for experimenting, designing, selecting, composing and implementing a specific interaction technique for a given task to achieve high usability.

The authors analyze the characteristics of the stereoscopic adapter, which is a cost-effective way to generate stereo video sequences with a camera. We also propose an efficient way to compensate for the inherent distortions. In general, stereo sequences can be captured using a pair of cameras but the resulting sequences tend to yield various well-known problems due to different characteristics of the pair of stereo cameras. Meanwhile, a camera with the stereoscopic adapter provides a natural way to capture and display stereoscopic video. It allows users to access all the functions built into the camera, e.g. zoom, auto-focus, auto-exposure, special effects, etc. The cost however is the reduced quality of the videos since the adapter allows capture of stereo video sequences in the field sequential format, i.e. left and right images in different scan lines, respectively. In addition, it generates size and color distortions due to the physical configuration of the mirror in the adapter. We analyze and compensate for such distortions to reduce possible errors in vision applications exploiting the stereo images. According to our preliminary study, the adapter with the proposed compensation scheme will pave the way for various low cost image based virtual reality applications at hand.

Usability has become one of the key ingredients in making virtual reality (VR) systems work, and a big part of a usable VR system is the design of effective interface/interaction schemes. We investigate the usability of various menu presentation and multi-modal selection schemes in immersive virtual environments. We have identified five major menu displays and 13 possible menu selection methods; among them, we have completed the usability testing for two interaction methods across the five display methods: (1) position control by tracking and command-giving by button-pressing, and (2) both position control and command-giving by gesture recognition. Other interaction methods, including by voice, remain to be investigated.