• Proceedings of the Korean Information Science Society Conference
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• 2003.10c
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• pp.319-321
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• 2003

모바일 컴퓨팅 환경은 크게 모바일 노드, 무선망, 그리고 이동성이라는 기술로 이루어진다. 이음새없는 (seamless) 이동성을 제공하기 위한 기존의 Shadow Registration 방법은 핸드오프가 발생하기 이전에 이웃한 모든 노드들(AAAF/sbu n/)에게 모바일 노드의 관련 정보를 사전등록(Shadow Registration)하는 방법을 제안하여 핸드오프 이후에 발생하는 끊김이나 지연을 방지하였다. 그러나 이러한 Shadow Registration의 경우 백본 네트워크에 불필요한 트래픽 발생 및 데이터 관리라는 문제를 야기시킨다. 본 논문은 이러한 문제점들을 개선하고자 새롭게 사전등록 트리거 영역(STR: Shadow Trigger Region)을 설정하고, STR 내에 모바일 노드(MN)가 위치할 경우 MN의 이동 방향을 이용하여 최소한의 사전등록영역(SRR: Shadow Registration Region)을 찾아내는 방법을 제안한다. 결과적으로 제안된 SRR 은 최대 2 개의 이웃노드(AAAF$_2$)에게만 사전등록을 요청하면 되므로, 기존의 방법에 비해 최대 ∑(n­2)번의 사전등록 횟수를 줄이면서 끊김과 지연도 방지할 수 있는 효과적인 방법이다.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.18 no.5
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• pp.105-111
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• 2004

This paper shows that active and reactive power load have significant positive relationship and there exist two types of relationship between them using Test Statistics. In investigating the cross plots at every hour, we found out that from 0 to 8 hours, there relationships are linear, while from 9 to 23 hours, they are two piece-wise linear. Also, reactive power loads was estimated and forecasted using active power load as the explanary variable with OLS (Ordinary Least Squares) regression methods. MAPE (Mean Absolute Percentage Error) for each model is calculated for one-hour ahead forecasting.

• Journal of the Korean Society of Hazard Mitigation
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• v.5 no.2 s.17
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• pp.45-56
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• 2005

Cloud meteorological properties over Daegwallyeong mountain area were analyzed for experimental cloud seeding which related to a feasibility study of fog modification. The cloud seeding for fog modification has been refocused to using hygroscopic chemical to dissipate warm fog. In this study, the statistics of fog observations were analyzed and discussed. Fog properties mostly showed the Summer warm fog, the early morning occurrences before to 6 o'clock AM, and 7 to 9 o'clock dissipation in the statistics. In the Spring and Winter season an easterly wind produced cold fog which is good applied with AgI seeding agents. Extrapolation of these results suggests that the suitable seeding method and material for fog modification will be introduced from the actual seeding experiments in the cold and warm fog.

• Journal of architectural history
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• v.27 no.2
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• pp.17-28
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• 2018

This study explores the space and society of Seorin-bang(瑞麟坊), using the Hanseong-bu family registry from the Gwangmu period to demonstrate the urban organizational units used during the late Joseon dynasty known as Seo(署)-Bang(坊)-Gye(契)-Dong(洞)-Tong(統)-Ho(戶). It seeks to examine how Seorin-bang's space and society changed with time. First, the study offers approximate demarcation for Gye and Dong through spatial verification of Bang-Gye-Dong-Tong-Ho of Seorin-bang in late Joseon Dynasty, whose precise locations were formerly undetermined. Second, it explores the relationships between Bang-Gye-Dong-Tong-Ho which has been widely understood to be hierarchical by previous studies, and classifies the relationship dynamics between Gye and Dong into four types. Third, the study finds that Seorin-bang retained much of its urban structure including roads, plots, and streams and maintained stable population distribution under the Japanese colonial rule, and continuously served as place of residency for many throughout the Gwangmu period. This study has major implications in that it illustrates space and society of Seorin-bang by converting the family registry from the late Joseon Dynasty into spatial data, and observes its changes subsequent to the Japanese colonial rule.

• Journal of Digital Contents Society
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• v.8 no.4
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• pp.593-600
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• 2007

Small computer systems such as mobile devices adopt NAND flash memories as their storage media. However, DBMS running on such systems are optimized to hard disks. When small computer systems use DBMS they usually use additional system layer, like FTL, that emulates flash memories as normal hard disks and DBMS cannot control flash memories directly. In this paper, we propose unified storage system that DBMS controls flash memories directly. We implemented the system in a real environment and proved the proposed system outperforms legacy systems.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.33 no.1C
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• pp.12-18
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• 2008

This paper This paper proposes a new inverse-quantization(IQ) table interpolation algorithm, specialized Digital Signal Processor(DSP) instructions and hardware architecture for digital audio codecs. Non-linear inverse quantization algorithm is representatively used in both MPEG-1 Layer-3 and MPEG-2/4 Advanced Audio Coding(AAC). The proposed instructions are optimized for the non-linear inverse quantization. The proposed algorithm can minimize operational complexity which reduces total computational load. Performance comparisons show a significant improvement of average error. The proposed instructions and hardware architecture can reduce 20% of the instruction counts and minimize computational loads of IQ algorithms effectively compared with existing IQ table interpolation algorithms. Proposed algorithm can implement commercial DSPs.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2003.11a
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• pp.201-204
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• 2003

본 논문에서는 디지털 데이터 방송에서 동기화 데이터 서비스를 제공하기 위한 전송 시스템과 이를 이용한 동기화 데이터 서비스 방법을 제안한다. 데이터 방송을 통해 전송되는 부가 데이터는 그 특징에 따라 비동기, 동기, 동기화 데이터로 구분된다. 이들 중 동기화 데이터는 사용자의 선택에 의해 데이터 방송 수신기에서 재생되는 비동기 데이터와는 달리 비디오 또는 오디오의 특정 장면에 통기되어 재생될 수 있는 데이터고서, 데이터를 전송하는 단계에서 데이터가 재생되어야 하는 시전의 시간 정보인 재생시각이 함께 전송되는 특징이 있다. 동기화 데이터의 이와 같은 특징으로 인해 현재 대부분의 데이터 방송에 사용되고 있는 비동기 데이터 서비스를 위한 전송 시스템은 동기화 데이터의 전송에는 부적합하며, 동기화 데이터 서비스를 위해서는 새로운 전송 시스템에 대한 연구가 필요하다. 본 논문에서는 데이터 방송을 동해 동기화 데이터 서비스를 제공하기 위해 기존의 비동기 데이터 전송 시스템에 MPEG-2 오디오/비디오 TS(Transport Stream)를 출력하는 장치와 동기화 데이터를 다중화 하는 장치를 추가한 새로운 동기화 데이터 전송 시스템과 이를 이용한 동기화 데이터 서비스 방법을 제안한다

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2006.05a
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• pp.197-200
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• 2006

A scene changing detection using histogram and header information of H.264 video stream is presented in this paper. The method using histogram is normal to be detect the changing scene. But this technique results in a lot of processing time because video data is compressed and decompressed to video stream and calculated the difference of histogram between scenes on the each frame. The method using H.264 header information is available to detect the scene change at real time without the process of calculation. Histogram and header information is more rapid for scene change detection with being the same performance in precision and recall.

• Journal for History of Mathematics
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• v.35 no.5
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• pp.131-146
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• 2022

This study is to find out how to use the materials of East Asian history in mathematics classroom. Although the use of the history of mathematics in classroom is gradually considered advantageous, the usage is mainly limited to Western mathematics history. As a result, students tend to misunderstand mathematics as a preexisting thing in Western Europe. To fix this trend, it is necessary to deal with more East Asian history of mathematics in mathematics classrooms. These activities will be more effective if they are organized in the context of students' real life or include experiential activities and discussions. Here, the study suggests a way to utilize the mathematical ideas of Bāguà and Liùshísìguà, which are easily encountered in everyday life, and some concepts presented in 『Nine Chapter』 of China and 『GuSuRyak』 of Joseon. Through this activity, it is also important for students to understand mathematics in a more everyday context, and to recognize that the modern mathematics culture has been formed by interacting and influencing each other, not by the east and the west.

• Journal of the Korean Association of Geographic Information Studies
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• v.8 no.3
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• pp.1-10
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• 2005

The purpose of this paper is to conduct an experimental measurement and analysis of cities' morphology. Fractal theory that is an effective tool for evaluating self-similarity and complexity of objects was applied. For the comparative analysis of fractailities and computational verification, two totally different cities in Japan were selected. They are Kitakyushu City, which is a big and fully developed city, and Jinguu Machi of which almost all the area is covered with agricultural land use. After converting vector data to raster data within GIS, fractal dimensions of two cases in Kitakyushu City and one case in Jinguu Machi were calculated. The calculation showed that two parts of Kitakyushu City were already fractal. Jinguu Machi, however, was difficult to find fractality. As a conclusion, fractal was proved to be an useful tool to estimate the shape of cities reflecting their internal spatial structure, that is self-similarity and complexity.