• Proceedings of the Korea Information Processing Society Conference
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• 2003.05a
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• pp.277-280
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• 2003

현재 많은 관심의 대상이 되고 있는 데이터 마이닝은 대용량의 데이터베이스로부터 일정한 패턴을 분류하여 지식의 형태로 추출하는 작업이다. 데이터 마이닝의 대표적인 기법인 군집화는 군집내의 유사성을 최대화하고 군집들간의 유사성을 최소화시키도록 데이터 집합을 분할하는 것이다. 데이터 마이닝에서 군집화는 대용량 데이터를 다루기 때문에 원시 데이터에 대한 접근횟수를 줄이고 알고리즘이 다루어야 할 데이터 구조의 크기를 줄이는 군집화 기법이 활발하게 사용된다. 그런데 기존의 군집화 알고리즘은 잡음에 매우 민감하고, local minima에 반응한다. 또한 사전에 군집의 개수를 미리 결정해야 하고, initialization 값에 다라 군집의 성능이 좌우되는 문제점이 있다. 본 연구에서는 유전자 알고리즘을 이용하여 자동으로 군집의 개수를 결정하는 군집화 알고리즘을 제안하고, 여기서 제시하는 적합도 함수의 최적화된 군집을 찾아내어 조금더 효율적인 알고리즘을 만들어 대용량 데이터를 다루는 데이터 마이닝에 적용해 보려한다.

• Proceedings of the Korea Information Processing Society Conference
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• 2010.11a
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• pp.1767-1769
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• 2010

본 논문은 그리드 혹은 클라우드 컴퓨팅환경과 같은 인터넷 기반의 대규모 분산 환경에서 데이터집약적인 작업의 실행에 있어서 확장성을 위해 필수적으로 고려되는 데이터 전송 부하를 분산시키는 기법을 논하고 있다. 우리는 다수의 메모리기반의 데이터 노드를 활용하여 분할기법(Partitioning)을 기반으로 데이터 전송 부하를 줄이고자 하며 다수의 데이터 노드에 실시간으로 최적의 데이터의 양을 공급하는 기법에 대한 이론적인 분석과 시뮬레이션을 통한 성능 검증을 포함하고 있다.

• Journal of the Korea institute for structural maintenance and inspection
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• v.25 no.2
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• pp.43-48
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• 2021

Precast concrete can be used to reduce construction period and enhance construct ability. However structural problems could be occurred due to the wrong application of boundary condition and misunderstanding of structural behavior in the process of segmentation of original structure system. I experienced a serious deflections and cracks due to the increase of bending moment and creep after the construction of precast concrete slab, and we learned that this is from the misunderstanding of support conditions and structure behaviors of precast slab panel. Two support columns under the precast slab are inserted to reduce the bending moment, and the camber according to jacking force should be estimated for the structural safety during the reinforcing work. A proper support condition and the flexural stiffness of precast concrete slab were applied to check the deflection and crack for existing structure by inverse analysis, and we can estimate the camber according to jacking force of the precast concrete slab, and suggest a method to make safe structure.

• Journal of the Korea Computer Industry Society
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• v.3 no.2
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• pp.209-216
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• 2002

World Wide Web has potential possibility of infrastructure for parallel computing environment connecting massive computing resources, not just platform to provide and share information via browser. The approach of Web-based parallel computing has many advantages of the ease of accessibility, scalability, cost-effectiveness, and utilization of existing networks. Applet has the possibility of decomposing the independent/parallel task, moving over network, and executing in computers connected in Web, but it lacks in the flexibility due to strict security semantic model. Therefore, in this paper, Web-based parallel computing environment using mobile agent, Aglet (Agile applet) was designed and possible implementation technologies and architecture were analyzed. And simple simulation and analysis was done compared with applet-based approach.

• Journal of KIISE:Computing Practices and Letters
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• v.7 no.6
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• pp.582-592
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• 2001

Video indexing plays an important role in the applications such as digital video libraries or web VOD which archive large volume of digital videos. Video indexing is usually based on video segmentation. In this paper, we propose a software tool called V2Web Studio which can generate video clips utilizing shot boundary detection algorithm. With the V2Web Studio, the process of clip generation consists of the following four steps: 1) Automatic detection of shot boundaries by parsing the video, 2) Elimination of errors by manually verifying the results of the detection, 3) Building a modeling structure of logical hierarchy using the verified shots, and 4) Generating multiple video clips corresponding to each logically modeled segment. The aforementioned steps are performed by shot detector, shot verifier, video modeler and clip generator in the V2Web Studio respectively.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.8
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• pp.8-16
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• 2016

This study presents the visualization of shape information based on Octree using 3D laser scanning. The process of visualization was established to construct the Octree structure from the 3D scan data. The scan data was converted to a 2D surface through the mesh technique and the surface was then converted to a 3D object through the Raster/Vector transformation. The 3D object was transmitted to the Octree Root Node and The shape information was constructed by the recursive partitioning of the Octree Root Node. The test-bed was selected as the steel bridge structure in Sungkyunkwan University. The shape information based on Octree was condensed into 89.3%. In addition, the Octree compressibility was confirmed to compare the shape information of the office building, a computer science campus in Germany and a New College in USA. The basis is created by the visualization of shape information for double-deck tunnel and it will be expected to improve the efficiency of structural health monitoring and maintenance.

• The Journal of the Korea Contents Association
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• v.10 no.10
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• pp.172-179
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• 2010

The study on works motivated from interest in the nature of matters and inherent visual-perceptual structure in them aims at expressing formative continuity of the connections of three dimensions of simple geometrical shapes such as circles and lines, which are characteristics of shape of molecules. With such a purpose, this study examined the geometrical shapes in modern arts and structural connection and symbolism of molecule structure, and based on such considerations, it expressed successive formative beauty which comes from repetitive connection between units by creating stereogram of simple geometrical shapes of molecule structure. The types of works include a method of connecting the units of molecule models and molecules seen in electron microscope with lines as a parameter and connecting units directly, which are used to express body accessory and metallic sculptures. Consequently, it attempted formation occurring spatial composition of continuity of division and duplication through direct connection between units and circular continuity coming from connection of simple geometrical shapes of molecule images such as spheres and curves transformed into stereogram.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.45 no.11
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• pp.71-76
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• 2008

H.264(or MPEG-4/AVC pt.10) is a high performance video coding standard, and is widely used. Variable length code (VLC) of the H.264 standard compresses data using the statistical distribution of values. A decoder parses the compressed bit stream and searches decoded values in lookup tables, and the decoding process is not easy to implement by hardware. We propose an architecture of variable length decoder(VLD) for the H.264 baseline profile(BP) L4. The CAVLD decodes syntax elements using the combination of arithmetic units and lookup tables for the optimized hardware architecture. A barral shifter and a first 1's detector parse NAL bit stream, and are shared by Exp-Golomb decoder and CAVLD. A FIFO memory between CAVLD and the reorder unit and a buffer at the output of the reorder unit eliminate the bottleneck of data stream. The proposed VLD is designed using Verilog-HDL and is implemented using an FPGA. The synthesis result using a 0.18um standard CMOS technology shows that the gate count is 22,604 and the decoder can process HD($1920{\times}1080$) video at 120MHz.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.26 no.10
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• pp.1551-1558
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• 2022

We propose a two-tier cooperative computing system comprised of a mobile device and an edge server for partial offloading of multi-branch structures in Fog/Edge Computing environments in this paper. The proposed system includes an algorithm for splitting up application service processing by using reconstructive linearization techniques for multi-branch structures, as well as an optimal collaboration algorithm based on partial offloading between mobile device and edge server. Furthermore, we formulate computation offloading and CNN layer scheduling as latency minimization problems and simulate the effectiveness of the proposed system. As a result of the experiment, the proposed algorithm is suitable for both DAG and chain topology, adapts well to different network conditions, and provides efficient task processing strategies and processing time when compared to local or edge-only executions. Furthermore, the proposed system can be used to conduct research on the optimization of the model for the optimal execution of application services on mobile devices and the efficient distribution of edge resource workloads.

• Korean Journal of Remote Sensing
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• v.22 no.6
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• pp.601-612
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• 2006

This study proposes RAG (Region Adjancency Graph)-based image segmentation for large imagery in remote sensing. The proposed algorithm uses CN-chain linking for computational efficiency and multi-window operation of sliding structure for memory efficiency. Region-merging due to RAG is a process to find an edge of the best merge and update the graph according to the merge. The CN-chain linking constructs a chain of the closest neighbors and finds the edge for merging two adjacent regions. It makes the computation time increase as much as an exact multiple in the increasement of image size. An RNV (Regional Neighbor Vector) is used to update the RAG according to the change in image configuration due to merging at each step. The analysis of large images requires an enormous amount of computational memory. The proposed sliding multi-window operation with horizontal structure considerably the memory capacity required for the analysis and then make it possible to apply the RAG-based segmentation for very large images. In this study, the proposed algorithm has been extensively evaluated using simulated images and the results have shown its potentiality for the application of remotely-sensed imagery.