Yoo-Sung Kim

Moflex transaction model for mobile heterogeneous multidatabase systems

Users on mobile hosts can access information from heterogeneous multidatabase systems by mobile transactions via wireless communication. Hence, a mobile transaction model should include not only features for heterogeneous multidatabase systems but also those for a mobile computing environment. In this paper, we propose a mobile transaction model to support the requirements of mobile heterogeneous multidatabase systems. The proposed Moflex (Mobile flexible) transaction model is able to support the management of mobility, heterogeniety and flexibility in the definition and execution of mobile transactions. Hence, the Moflex transaction model can be suitable for mobile heterogeneous multidatabase systems that have low power capability, low bandwidth and a high possibility of communication failure.

Probability-Based Tile Pre-fetching and Cache Replacement Algorithms for Web Geographical Information Systems

In this paper, an effective probability-based tile pre-fetching algorithm and a collaborative cache replacement algorithm for Web geographical information systems (Web GISs) are proposed. The proposed tile prefetching algorithm can approximate which tiles will be used in advance based on the global tile access pattern of all users and the semantics of query so that a user request will be answered quickly since the needed tiles are likely in cache database. When a client runs out of cache space for newly down-loaded tiles, the proposed cache replacement algorithm determines which tiles should be replaced based on the future access probabilities. By combining the proposed tile pre-fetching algorithm with the cache replacement algorithm, the response time for user requests can be improved substantially in Web GIS systems.

Divided naevus on the penis

Sir, Molluscum contagiosum (MC) is a poxvirus skin infection that often complicates the course of patients with acquired or iatrogenic immunosuppression. Both the clinical and histological features of disease in these cases may be atypical. We report the unique clinical and histological features of a case of fulminant MC infection with concomitant leukaemia cutis in a patient with relapse of chronic myeloid leukaemia (CML) after allogeneic bone marrow transplantation (BMT). A 49-year-old Chinese woman underwent BMT (conditioning: busulphan, cyclophosphamide, total body irradiation) from an HLA identical sister for Ph positive CML in accelerated phase. She engrafted uneventfully with no chronic graft-vs.-host disease (GVHD). Serial bone marrow reassessments, up to 18 months post-BMT, were negative for residual disease by polymerase chain reaction and cytogenetics. At 36 months, she was found to have haematological relapse of CML, with cytogenetic subclonal evolution. She was treated with hydroxyurea and donor lymphocyte infusions (DLI) (6 ́1 10 kg cells infused in three doses) to enhance the graft-vs.-leukaemia (GVL) effect. There was good control of the peripheral cell counts and no evidence of GVHD. A repeat marrow biopsy at 40 months showed suppression of the abnormal clone to 3% of analysed metaphases. Unfortunately, at 46 months the disease progressed again with increased neutrophil counts (52 10 L), and leukaemia cutis documented by skin biopsy (Figs 1a, 1b). This was treated with combination chemotherapy (cytosine arabinoside 150 mg 5, thioguanine 160 mg 5) resulting in normalization of cell count and resolution of all skin lesions. A second course of DLI (4 ́2 10 kg cells) was administered at 49 months post-BMT. Three weeks after DLI, however, the patient presented with a dense eruption of erythematous papular lesions over the entire face, upper limbs and upper trunk. Photography of the lesions was refused. A biopsy of one lesion showed lobules of abnormal epidermal cells with cytoplasm packed with eosinophilic viral inclusion bodies (Fig. 2a). Electron microscopy showed numerous intracytoplasmic poxvirus particles (240 95 nm in size) within the abnormal epidermal cells, consistent with MC (Fig. 2b). In addition, an infiltrate of promyelocytes and immature myeloid blast cells was seen, consistent with recurrent leukaemia cutis. She died 1 week later of an intracranial haemorrhage, probably related to intracerebral disease. The use of DLI is the treatment of choice for relapse of CML after BMT. The main side-effects are profound marrow and immune suppression, with or without acute and chronic GVHD. Reactivation of dormant DNA viruses like cytomegalovirus, varicella zoster and hepatitis B viruses are potential complications of immunosuppression caused by DLI. This is the first report of severe MC complicating DLI. In immunosuppressed hosts, due to the fulminant replication of the poxvirus, the clinical and pathological features of MC can be highly variable, and aggressive treatment is often needed. Viral particles have even been found in the histologically normal skin epidermis adjacent to MC lesions in patients infected with HIV. There have been two previous reports of skin changes in MC mimicking haematological malignancy involving the skin. In our case, the clinical setting and pathological features are highly supportive of a genuine double pathology. It is recognized that post-BMT patients have an increased incidence of leukaemic involvement of extramedullary sites, including the skin. The incidence may be even higher in patients salvaged with DLI, due to a weaker GVL effect outside the marrow. The precise colocalization of MC replication and leukaemic infiltration in the skin lesions may have been due to a high concentration of chemotactic

A melody-based similarity computation algorithm for musical information

A melody-based similarity computation algorithm for musical information is proposed in which melodies are used as the basic features for calculating the similarity between two music files. In multimedia information systems, in order to retrieve the needed information appropriately, content-based retrieval strategies are used which are based on the similarity between the users query and the stored multimedia information. Hence, an effective similarity computation algorithm is basically required for content-based retrieval for music information. In the proposed algorithm, the pitches and lengths of the musical notes which compose the melodies of two corresponding music files are compared, and then the comparison results are finally condensed into a similarity value between the two corresponding music files. Experimental results show that the proposed algorithm is able to calculate the similarity value between music files appropriately on the basis of melodies.

Zone-Based clustering for intrusion detection architecture in ad-hoc networks

Setting up an IDS architecture on ad-hoc network is hard because it is not easy to find suitable locations to setup IDSs. One way is to divide the network into a set of clusters and put IDS on each cluster head. However traditional clustering techniques for ad-hoc network have been developed for routing purpose, and they tend to produce duplicate nodes or fragmented clusters as a result of utilizing maximum connectivity for routing. Most of recent clustering algorithm for IDS are also based on them and show similar problems. In this paper, we suggest to divide the network first into zones which are supersets of clusters and to control the clustering process globally within each zone to produce more efficient clusters in terms of connectivity and load balance. The algorithm is explained in detail and shows about 32% less load concentration in cluster heads than traditional techniques.

Extracting Theme Melodies by Using a Graphical Clustering Algorithm for Content-Based Music Information Retrieval

We proposed the mechanism of extracting theme melodies from a song by using a graphical clustering algorithm. In the proposed mechanism, a song is split into the set of motifs each of which is the minimum meaningful unit. Then the system clusters the motifs into groups based on the similarity values calculated between all pairs of motifs so that each cluster has higher similarity values between them than others. From each clusters, the system selects a theme melody based on the positions of the motif within a song and the maximum summation of similarity values of edges adjacent to the motif node in each cluster. As the experimental results, we showed an example in which we describe how the theme melodies of a song can be extracted by using the proposed algorithm.

Prefetching Tiled Internet Data Using a Neighbor Selection Markov Chain

A large data file in the internet such as a map is served in small pieces, called tiles. To improve the service speed for such data, we can prefetch future tiles while the current one is being displayed. Traditional prefetching techniques examine the transition probabilities among the tiles to predict the next tile to be requested. However, when the tile space is very huge, and a large portion of it is accessed with even distribution, it is very costly to monitor all those tiles. In this paper, we propose a technique that captures the regularity in the tile request pattern by using an NSMC (Neighbor Selection Markov Chain) and predicts future tile requests based on it. The required regularity to use our technique is that the next tile to be requested is dependent on previous k movements (or requests) in the tile space. Map shows such regularity in a sense. Electronic books show a strong such regularity. We show how to build an NSMC and measure its prediction capability through experimentations.

Face occlusion detection using skin color ratio and LBP features for intelligent video surveillance systems

A face occlusion detection scheme which is based on both skin color ratio (SCR) and Local Binary Pattern (LBP) feature, is proposed. The proposed method mainly consists of four steps: foreground extraction, head detection, feature extraction, and occlusion detection. First, foreground is extracted by codebook background subtraction algorithm. Then, the head region is located using HOG head detector. After that, the skin-color ratio and LBP feature are extracted. Finally, SVM is trained based on LBP feature. The recognition result of SVM and the result of skin-color ratio feature are merged by weighted voting strategy, and then occluded faces are classified as three categories: concealed, partially concealed, and visible. Experimental results show that the proposed detection system can achieve desirable results in intelligent video surveillance systems.

Implementation of High-Reliable MVB Network for Safety System of Nuclear Power Plant

The computer network plays an important role in modern digital controllers within a safety system of a nuclear power plant. For the reliable and realtime data communication between controllers, this paper proposes a modified high-reliable MVB(multi-function vehicle bus) as a main control network for a safety system of a nuclear power plant. The proposed network supports the state-based communication in order to ensure the deterministic communication latency, and very fast network recovery when the bus master fails compare to the standard MVB. This paper also shows the implementation results using a FPGA-based testbed.

A SOAP-Based Framework for the Internetworked Distributed Control Systems

Emerging IT technologies, specially Internet communication and webbased technologies are adopted to the modern distributed control systems. This paper defines a functional framework for the webbased applications of a distributed control system connected by Internet. XML(eXtensible Markup Language) is used for representing a control system and control devices. These IT technologies make a distributed control system more flexible and scalable than existing distributed control systems with the standard RMI protocols such as CORBA or DCOM.