• Journal of Industrial Technology
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• v.20 no.B
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• pp.213-218
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• 2000

The nearest neighbor query is an important operation widely used in multimedia databases for finding the object that is most similar to a given query object. Most of techniques for processing nearest neighbor queries employ multidimensional indexes for effective indexing of objects. However, the performance of previous multidimensional indexes, which use N-dimensional rectangles or spheres for representing the capsule of the object cluster, deteriorates seriously as the number of dimensions gets higher. This paper proposes a new index structure based singular value decomposition resolving this problem and the query processing method using it. We also verify the superiority of our approach through performance evaluation by performing extensive experiments.

• Journal of Korea Multimedia Society
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• v.17 no.5
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• pp.631-639
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• 2014

Recently, research on Media Access Control (MAC) techniques for underwater acoustic communication has been conducted actively. For successful acoustic communication in underwater conditions, development of environmentally adaptive MAC techniques, which is taking narrow bandwidth, distance, depth, noise level, salinity, multipath and etc into account, is an especially important work. In this paper, knowledge based system is introduced not only to obtain adaptive and optimal communication parameters but also increase network efficiency and availability by requesting change of MAC techniques based on decisions from knowledge-based system Smart Decision Block (SDB). Computer simulations were also conducted to verify the performance of the proposed system in underwater conditions.

• Journal of Korea Multimedia Society
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• v.22 no.7
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• pp.759-769
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• 2019

Since a surgery simulation should be able to represent the internal structure of the human body, it is advantageous to adopt volume based techniques rather than polygon based techniques. However, the volume based techniques induce large computation to deform heterogeneous volume datasets such as bones and muscles. In this study, we propose a new method to deform volume data using multi-core CPUs. By improving previous studies, the proposed method minimizes unnecessary propagation operations. Moreover, we propose an efficient task-partitioning method for volume deformation using multi-core CPUs. As a result, we can simulate the deformation of heterogeneous volume data at an interactive speed without special hardware.

• Journal of Multimedia Information System
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• v.6 no.2
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• pp.87-90
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• 2019

Machine learning techniques have been applied in almost all the domains of human life to aid and enhance the problem solving capabilities of the system. The field of medical science has improved to a greater extent with the advent and application of these techniques. Efficient expert systems using various soft computing techniques like artificial neural network, Fuzzy Logic, Genetic algorithm, Hybrid system, etc. are being developed to equip medical practitioner with better and effective diagnosing capabilities. In this paper, a comparative study to evaluate the predictive performance of subtractive clustering based ANFIS hybrid system (SCANFIS) with Fuzzy C-Means (FCM) based ANFIS system (FCMANFIS) for Alzheimer disease (AD) has been taken. To evaluate the performance of these two systems, three parameters i.e. root mean square error (RMSE), prediction accuracy and precision are implemented. Experimental results demonstrated that the FCMANFIS model produce better results when compared to SCANFIS model in predictive analysis of Alzheimer disease (AD).

• Journal of Korea Multimedia Society
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• v.22 no.1
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• pp.99-109
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• 2019

Realistic rendering of natural phenomena is a difficult problem. Many environmental factors must be considered to simulate this phenomenon. At the same time, we need to think about their computational complexity to be simulated with computer algorithm One of the most difficult problems in creating weather conditions is the rain. To simulate realistic rainy scene, you have to consider the physical properties of rain and the environmental where the rain is falling down as well. In this paper, we survey the modeling and rendering techniques for realistic rainfall scenes from three different aspects. First, we list up techniques for modeling raindrop dynamics. Second, we survey the rendering techniques that render the raindrop in the environment. Third, we take a look at the hybrid methods that combines the rendering the modeling at the same time. For each aspect, we compare the algorithms in terms of implementation and their speciality.

• Proceedings of the Korea Information Processing Society Conference
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• 2013.05a
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• pp.898-899
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• 2013

There are numerous approaches to improve the performances of database systems. The most efficient ones are considered to be implementing an effective database indexing technique. This must guarantee the balance between the memory, storage resources and processor of the database server according to the type, structure, the physical organization and the cardinality of data, the type of queries and the number of competing transactions. The challenge is to find an appropriate index type that would suite these requirements. In this paper, we provide an overview of the most used database indexing techniques such as B-tree index and Bitmap index, present an analysis of these techniques and discuss their limitations.

• Journal of Advanced Marine Engineering and Technology
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• v.22 no.5
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• pp.652-659
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• 1998

The present study is aimed to develop a new PIV operating software through optimization of vector tracking identification including versatile pre-processings and post-processing techniques. And the result exhibits an improved version corresponding various input and output multimedia compared to previous commercial software developed by other makers. An upgraded identification method called grey-level cross correlation coefficient method by direct calculation is suggested and related user-friendly pop-up menu are also represented. Post-processings comprising turbulence statistics are also introduced with graphic output functions.

• Bulletin of the Korean Chemical Society
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• v.25 no.10
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• pp.1571-1574
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• 2004

• The Transactions of the Korea Information Processing Society
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• v.5 no.9
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• pp.2233-2247
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• 1998

With the growth of World Wide Web, multimedia electronic documents have been frequently used in a lot of applications. Especially, digital libraries tliat deal with huge and various multimedia electronic documents need to support efficient searcli techniques and systematical management techniques. In this paper, we suggest an extended Dublin Core metadata to store and search the multimedia electronic documents managed at digital libraries. We also design a document database schema based on the extended Dublin Core metadata and implement a svstem, called xD-MMS which manages the multimedia electronic documents.

• Journal of Korea Multimedia Society
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• v.19 no.8
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• pp.1479-1486
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• 2016

According to the advancement of display devices, the multi-screen contents display environment is growing to be accepted for the display exhibition area. The objectives of this research are to find communications technology and to design an editor interface of contents delivery system for the larger and adaptive multi-display workspaces. The proposed system can find existence of display devices and get information without any additional tools like marker, and can recognize device layout with only web-cam and image processing technology. The multi-display contents delivery system is composed of devices with three roles; display device, editor device, and fixed server. The editor device which has the role of main control uses UPnP technology to find existence and receive information of display devices. extract appointed color in captured picture using a tracking library to recognize the physical layout of display devices. After the device information and physical layout of display devices are connected, the content delivery system allows the display contents to be sent to the corresponding display devices through WebSocket technology. Also the experimental results show the possibility of our device connection and layout recognition techniques can be utilized for the large spaced and adaptive multi-display applications.