Distributed similarity search algorithm in distributed heterogeneous multimedia databases
The collection fusion problem in multimedia databases is concerned with the merging of results retrieved by content based retrieval from distributed heterogeneous multimedia databases in order to find the most similar objects to a query object. We propose distributed similarity search algorithms, two heuristic algorithms and an algorithm using the linear regression, to solve this problem. To our knowledge, these algorithms are the first research results in the area of distributed content based retrieval for heterogeneous multimedia databases.

title: Similarity search for multidimensional data sequences
abstract: Time series data, which are a series of one dimensional real numbers, have been studied in various database applications. We extend the traditional similarity search methods on time series data to support a multidimensional data sequence, such as a video stream. We investigate the problem of retrieving similar multidimensional data sequences from a large database. To prune irrelevant sequences in a database, we introduce correct and efficient similarity functions. Both data sequences and query sequences are partitioned into subsequences, and each of them is represented by a Minimum Bounding Rectangle (MBR). The query processing is based upon these MBRs, instead of scanning data elements of entire sequences. Our method is designed: (1) to select candidate sequences in a database, and (2) to find the subsequences of a selected sequence, each of which falls under the given threshold. The latter is of special importance in the case of retrieving subsequences from large and complex sequences such as video. By using it, we do not need to browse the whole of the selected video stream, but just browse the sub-streams to find a scene we want. We have performed an extensive experiment on synthetic, as well as real data sequences (a collection of TV news, dramas, and documentary videos) to evaluate our proposed method. The experiment demonstrates that 73-94 percent of irrelevant sequences are pruned using the proposed method, resulting in 16-28 times faster response time compared with that of the sequential search.

title: Optimizing the Order of Taxon Addition in Phylogenetic Tree Construction Using Genetic Algorithm
abstract: Phylogenetics has gained in public favor for the analysis of DNA sequence data as molecular biology has advanced. Among a number of algorithms for phylogenetics, the fastDNAml is considered to have reasonable computational cost and performance. However, it has a defect that its performance is likely to be significantly affected by the order of taxon addition. In this paper, we propose a genetic algorithm for optimizing the order of taxon addition in the fastDNAml. Experimental results show that the fastDNAml with the optimized order of taxon addition constructs more probable evolutionary trees in terms of the maximum likelihood.

title: Responsive Multimedia System for Virtual Storytelling
abstract: In this paper, we propose Responsive Multimedia System (RMS) for a virtual storytelling. It consists of three key components; Multi-modal Tangible User Interface (MTUI), a Unified Context-aware Application Model for Virtual Environments (vr-UCAM), and Virtual Environment Manager (VEManager). MTUI allows users to interact with virtual environments (VE) through human’s senses by exploiting tangible, haptic and vision-based interfaces. vr-UCAM decides reactions of VE according to multi-modal input. VEManager generates dynamic VE by applying the reactions and display it through 3D graphics and 3D sounds, etc. To demonstrate an effectiveness of the proposed system, we implemented a virtual storytelling system which unfolds a legend of Unju Temple. We believe the proposed system plays an important role in implementing various entertainment applications.

title: An arbitration look-ahead scheme for reducing end-to-end latency in networks on chip
abstract: With the increasing complexity of system-on-chips, networks on chip (NoC) using multi-hop switching require low end-to-end latency for QoS guarantees. An arbitration look-ahead scheme is proposed to reduce the end-to-end packet latency in the NoC. Its packet arbitration at each switch is completed a few cycles in advance of the packet arrival. As a result, a packet bypasses the switch without the latency of input queuing and arbitration. This scheme is analyzed on a 4/spl times/4 mesh topology. A maximum 65% and average 26% latency reduction are obtained under random traffic. Latency reduction up to 36% is achieved under multimedia traffic.

title: UAMAC: Unidirectional-Link Aware MAC Protocol for Heterogeneous Ad Hoc Networks
abstract: In heterogeneous ad hoc networks, high-power nodes could potentially interfere with any on-going transmissions of low-power nodes. In this paper, we propose a unidirectional-link aware MAC protocol (UAMAC) which prevents such an interference problem by reserving the wireless channel of unidirectional high-power node selectively over one-hop. Our preliminary performance results show that the UAMAC works well in these heterogeneous environments with unidirectional links.

title: Designated Verification of Non-invertible Watermark
abstract: Digital watermark has been proposed as the means for copyright protection of multimedia data in network-based distribution framework. However, existing digital watermarking mechanisms have some problems that they cannot resolve the rightful ownership alone. Specially, someone can provide counterfeited watermark which can be performed on a watermarked image to allow multiple claims of rightful ownership. In this paper, we use designated verification method for undeniable signatures in the watermarking process. The confirmer of watermark can sure that only the intended verifier(s) can be convinced about the validity or invalidity of the signature.