• Magazine of the Korean Society of Hazard Mitigation
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• v.7 no.3
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• pp.75-81
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• 2007

1. 가을철에는 36년 평균($1971{\sim}2006$년) 11.1 (41.6%)개 발생, 0.8개가 우리나라에 영향을 줌(표 1, 그림 1) - 9월 발생 태풍 총 175개(연평균 4.9개) o 비상구역 진입태풍 51개(연평균 1.4개) o 우리나라에 27개 영향(연평균 0.8개) - 10월 발생 태풍 총 135개(연평균 3.8개) o 비상구역 진입태풍 17개(연평균 0.5개) o 우리나라에 3개 영향 - 11월 발생 태풍 충 86개(연평균 2.4개) o 비상구역 진입태풍 3개 o 우리나라에 영향 없음 * 연평균 계산은 소수 둘째자리에서 반올림한 결과임. 2. 가을철 태풍발생수의 장기간 변동 특성(그림 2) - 많이 발생하는 해와 적게 발생하는 해가 주기적으로 반복되고 있음. - 1990년대 후반부터 평년보다 적게 발생하는 경향이 지속되고 있음. 3. 가을철 태풍으로 인한 인명 재산 피해 현황(표 3과 4) - 인명 피해 : 최근 감소 추세 o $2002.8.30{\sim}9.1$ 루사(RUSA, 0215), 246명 (사망 실종 포함) o 재산 피해 최근 증가 추세 o $2002.8.30{\sim}9.1$ 루사 (RUSA, 0215) 5,262,200(백만원) o $2003.9.12{\sim}9.13$ 매미(MABMI, 0314) 4,222,486(백만원) 4. 추석 기간 동안 우리나라에 영향을 준 태풍(표 5) - $1971{\sim}2006$년(36년) 동안 4회 o 1986, 1997, 2000, 2003 o 특히 $2003.9.12{\sim}13$ 매미(0314)에 의한 강풍과 강수로 인하여 막대한 피해 유발 : 고산(12일) 최대풍속 51.1m/s 전남남해안, 영남지방, 강원도 영동지방 $100{\sim}450mm$.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.9
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• pp.5790-5795
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• 2014

Elliptic curve cryptography (ECC) is an extremely important part of information protection systems because it has outstanding safety among public key encryption algorithms. On the other hand, as ECC cannot obtain accurate values using a real number field because of the slow calculation and errors from rounding off, studies of ECC have focused on a finite field. If ECC can be extended to the real number field, more diverse keys can be selected compared to ECC only based on a finite field. Accordingly, in this paper, a method for constructing a cryptographic system with a high degree of safety is proposed through the diversification of keys selected by the user based on the operant extension method instead of extracting keys only using integer values.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.18 no.10
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• pp.1433-1443
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• 1993

DCT(Discrete Cosine Transform) / IDCT(Inverse DCT) is widely used in various image compression and decompression systems as well as in DSP(Digital Signal Processing) applications. Since DCT/ IDCT is one of the most complicated part of the compression system, the performance of the system can be greatly enchanced by improving the speed of DCT/IDCT operation. In this thesis, we designed a DCT/IDCT core processor using module generator technique. By utilizing the partial sum and DA(Distributed Arithmetic) techniques, the DCT/ IDCT core processor is designed within small area. It is also designed to perform the IDCT(Inverse DCT) operation with little additional circuitry. The pipeline structure of the core processor enables the high performance, and the high accuracy of the DCT/IDCT operation is obtained by having fewer rounding stages. The proposed design is independent of design rules, and the number of the input bits and the accuracy of the internal calculation coa be easily adjusted due to the module generator technique. The accuracy of the processor satisfies the specifications in CCITT recommendation H, 261.

• Education of Primary School Mathematics
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• v.24 no.2
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• pp.103-114
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• 2021

In this study I recognized the problems with the use of the terms 'quotient' and 'reminder' in the division of decimal and explored ways to improve them. The prior studies and current textbooks critically analyzed because each researcher has different views on the use of the terms 'quotient' and 'reminder' because of the same view of the values in the division calculation. As a result of this study, I proposed to view the result 'q' and 'r' of division of decimals by division algorithms b=a×q+r as 'quotient' and 'reminder', and the amount equal to or smaller to q the problem context as a final 'result value' and the residual value as 'remained value'. It was also proposed that the approximate value represented by rounding the quotient should not be referred to as 'quotient'.

• Analytical Science and Technology
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• v.21 no.3
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• pp.174-182
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• 2008

The study on the development of rapid analytical method of PCBs containing waste was performed by considering the extraction, column cleanup process, analytical condition and so on. In the established method, new sample clean-up procedure, new quantification peaks and temperature program were introduced. Method detection limit of the method was 0.5 mg/L, and the method could save the total run time to 2/3, therefore save the analysis cost, The new rapid analytical method of transformer oil was suggested to the waste official test method.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.48 no.10
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• pp.82-90
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• 2011

Because of the development of Smart phone devices, the demands of high performance FPU(Floating-point Unit) becomes increasing. Therefore, we propose the high-speed single-/double-precision FPU design that includes an elementary add/sub unit and improved multiplier and compare and convert units. The most commonly used add/sub unit is optimized by the parallel rounding unit. The matrix operation is used in complex calculation something like a graphic calculation. We designed the Multiply-Add Fused(MAF) instead of multiplier to calculate the matrix more quickly. The branch instruction that is decided by the compare operation is very frequently used in various programs. We bypassed the result of the compare operation before all the pipeline processes ended to decrease the total execution time. And we included additional convert operations that are added in IEEE754-2008 standard. To verify our RTL designs, we chose four hundred thousand test vectors by weighted random method and simulated each unit. The FPU that was synthesized by Samsung's 45-nm low-power process satisfied the 600-MHz operation frequency. And we confirm a reduction in area by comparing the improved FPU with the existing FPU.

• Journal of Broadcast Engineering
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• v.13 no.5
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• pp.622-635
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• 2008

Recently, high definition media services like HDTV and IPTV are growing. A fast reduced-size image extracting method is required to meet what those services require. Conventional DC image extracting methods, however, can't be applied to H.264/AVC streams since a spatial domain prediction scheme is adopted in H.264/AVC intra mode. To solve this problem, a thumbnail extraction method in H.264/AVC was proposed. However, the method has mismatch problem which was caused by round-off operation in intra prediction and mismatch between integer and floating point calculation. In this paper, we propose an error compensation method for extracting thumbnail directly in H.264/AVC bitstreams. The compensation method introduces the mismatch problem in thumbnail extraction and presents compensation values. Through the implementation and performance evaluation, proposed method compensated round-off error efficiently in D1 and HD sequences while the additional extraction time is negligible.