• 제목/요약/키워드: block length

검색결과 684건 처리시간 0.031초

A New BISON-like Construction Block Cipher: DBISON

  • Zhao, Haixia;Wei, Yongzhuang;Liu, Zhenghong
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • 제16권5호
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    • pp.1611-1633
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    • 2022
  • At EUROCRYPT 2019, a new block cipher algorithm called BISON was proposed by Canteaut et al. which uses a novel structure named as Whitened Swap-Or-Not (WSN). Unlike the traditional wide trail strategy, the differential and linear properties of this algorithm can be easily determined. However, the encryption speed of the BISON algorithm is quite low due to a large number of iterative rounds needed to ensure certain security margins. Commonly, denoting by n is the data block length, this design requires 3n encryption rounds. Moreover, the block size n of BISON is always odd, which is not convenient for operations performed on a byte level. In order to overcome these issues, we propose a new block cipher, named DBISON, which more efficiently employs the ideas of double layers typical to the BISON-like construction. More precisely, DBISON divides the input into two parts of size n/2 bits and performs the round computations in parallel, which leads to an increased encryption speed. In particular, the data block length n of DBISON can be even, which gives certain additional implementation benefits over BISON. Furthermore, the resistance of DBISON against differential and linear attacks is also investigated. It is shown the maximal differential probability (MDP) is 1/2n-1 for n encryption rounds and that the maximal linear probability (MLP) is strictly less than 1/2n-1 when (n/2+3) iterative encryption rounds are used. These estimates are very close to the ideal values when n is close to 256.

등산복 업체현황 및 아이템별 패턴 비교분석 연구 (A Study on the Current State of Outdoor Clothing Companie and their Comparison and Analysis according to the Items)

  • 이은혜
    • 한국의류학회지
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    • 제35권9호
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    • pp.1049-1059
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    • 2011
  • This study investigates the current state of companies that manufacture and sell outdoor wear. A survey was conducted to identify what problems they had and what aspects they needed to supplement through a comparison and analysis of their block patterns. Companies that manufactured outdoor wear and those that sold them were separately surveyed to understand their current state. The manufactures included 4 companies and 14 sellers. The survey used interviews to cover the areas of target consumers, development patterns, production lines, body size, nominal size, production size, and functional materials for each item, and aspects that need improvement. The survey period was from September $3^{rd}$ to $10^{th}$ 2008. There were three block patterns for jackets, T-shirts, and pants. The investigator collected the patterns used by three outdoor clothing manu-facturers for comparison and assessment. As a result, the mean age of the target consumers set by the outdoor clothing manufacturers and sellers was 25.3-50.7 and 29.2-42.5, respectively, which shows that the outdoor clothing had a wider distribution of target consumers than the sellers. It is imperative for them to segment and differentiate the target consumers and concepts. The basic body measurements the companies used to draw the upper and lower garment patterns were the bust circumference for the upper garment patterns and the waist circumference for the lower garment patterns. The basic nominal size was 95 for the upper garment and 70 for the lower garment. Also analyzed were the block patterns according to the items to understand the pattern characteristics of each of the companies. There were a total of 35, 36, and 30 items for the jackets, T-shirts, and pants, respectively, to measure size. The items were then compared with one another in mean and standard deviation. The analysis indicate that the block patterns were not fit for women in their twenties or thirties to wear and required revisions in the length of the upper garment, the height of sleeve cap, bust circumference, hip length, and pant length.

Performance Evaluation of Access Channel Slot Acquisition in Cellular DS/CDMA Reverse Link

  • Kang, Bub-Joo;Han, Young-Nam
    • ETRI Journal
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    • 제20권1호
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    • pp.16-27
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    • 1998
  • In this paper, we consider the acquisition performance of an IS-95 reverse link access channel slot as a function of system design parameters such as postdetection integration length and the number of access channel message block repetitons. The uncertainty region of the reverse link spreading codes compared to that of forward link is very small, since the uncertainty region of the reverse link is determined by a cell radius. Thus, the parallel acquisiton technique in the reverse link is more efficient than a serial acquisition technique in terms of implementation and of acquisition time. The parallel acquisition is achieved by a bank of N parallel I/Q noncoherent correlator are analyzed for band-limited noise and the Rayleigh fast fading channel. The detection probability is derived for multiple correct code-phase offsets and multipath fading. The probability of no message error is derived when rake combining, access channel message block combining, and Viterbi decoding are applied. Numerical results provide the acquisition performance for system design parameters such as postdetection integration length and number of access channel message block repetitions in case of a random access on a mobile station.

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Packet Size Optimization for Improving the Energy Efficiency in Body Sensor Networks

  • Domingo, Mari Carmen
    • ETRI Journal
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    • 제33권3호
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    • pp.299-309
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    • 2011
  • Energy consumption is a key issue in body sensor networks (BSNs) since energy-constrained sensors monitor the vital signs of human beings in healthcare applications. In this paper, packet size optimization for BSNs has been analyzed to improve the efficiency of energy consumption. Existing studies on packet size optimization in wireless sensor networks cannot be applied to BSNs because the different operational characteristics of nodes and the channel effects of in-body and on-body propagation cannot be captured. In this paper, automatic repeat request (ARQ), forward error correction (FEC) block codes, and FEC convolutional codes have been analyzed regarding their energy efficiency. The hop-length extension technique has been applied to improve this metric with FEC block codes. The theoretical analysis and the numerical evaluations reveal that exploiting FEC schemes improves the energy efficiency, increases the optimal payload packet size, and extends the hop length for all scenarios for in-body and on-body propagation.

Pareto-Based Multi-Objective Optimization for Two-Block Class-Based Storage Warehouse Design

  • Sooksaksun, Natanaree
    • Industrial Engineering and Management Systems
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    • 제11권4호
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    • pp.331-338
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    • 2012
  • This research proposes a Pareto-based multi-objective optimization approach to class-based storage warehouse design, considering a two-block warehouse that operates under the class-based storage policy in a low-level, picker-to-part and narrow aisle warehousing system. A mathematical model is formulated to determine the number of aisles, the length of aisle and the partial length of each pick aisle to allocate to each product class that minimizes the travel distance and maximizes the usable storage space. A solution approach based on multiple objective particle swarm optimization is proposed to find the Pareto front of the problems. Numerical examples are given to show how to apply the proposed algorithm. The results from the examples show that the proposed algorithm can provide design alternatives to conflicting warehouse design decisions.

서브 블록을 이용한 MPEG-2 인트라 프레임의 시간적 오류 은닉 (Subblock Based Temporal Error Concealment of Intra Frame for MPEG-2)

  • 류철;김원락
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2005년도 심포지엄 논문집 정보 및 제어부문
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    • pp.167-169
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    • 2005
  • The occurrence of a single bit error in transmission bitstream leads to serious temporal and spatial errors. Because moving picture coding as MPEG-2 based on block coding algorithm uses variable length coding and motion compensation coding algorithm. In this paper, we propose algorithm to conceal occurred error of I-frames in transmission channel using data of the neighboring blocks in decoder. We divide a damaged macroblock of I-frame into four sub blocks and compose new macroblock using the neighboring blocks for each sub block. We estimate the block with minimum difference value through block matching with previous frame for new macroblocks and replace each estimated block with damaged sub block in the same position. Through simulation results, the proposed algorithm will be applied to a characteristic of moving with effect and shows better performance than conventional error concealment algorithms from visual and PSNR of view.

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볏짚재를 활용한 식생콘크리트 블록 개발 및 사면 적용성에 관한 실험적 연구 (Experimental Study on Development of Plantable Concrete Block Using Rice Straw Ash and Application for Inclined Plane)

  • 성찬용;김영익
    • 한국농공학회지
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    • 제45권4호
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    • pp.107-114
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    • 2003
  • This study was performed to develop the plantable concrete block using rice straw ash and apply for inclined plane. For the planting, plantable concrete block needs infiltration of water and air through void of block. The materials used for plantable concrete block are cement, rice straw ash, and coarse aggregate (5-10, 10-20 mm). Plantable block size is $23\times23\times4$ cm, and species of planting are Tall fescue, Lespedeza cyrtobotrya and Lespedeza cuneata. At the 6 months after seeding, germination ratio and grown-up length of Tall fescue, Lespedeza cyrtobotrya and Lespedeza cuneata are shown in 90%, 60%, 50%, and 40~50 cm, 90~120 cm, 60~75 cm, respectively.

FPGA 구조 및 로직 블록의 설계에 관한 연구 (A study on the architecture and logic block design of FPGA)

  • 윤여환;문중석;문병모;안성근;정덕균
    • 전자공학회논문지A
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    • 제33A권11호
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    • pp.140-151
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    • 1996
  • In this study, we designed the routing structure and logic block of a SRAM cell-based FPGA with symmetrical-array architecture. The designed routing structure is composed of switch matrices, routing channels and I/O blocks, and the routing channels can be subdivided into single length channels, double length channels and global length channels. The interconnection between wires is made through SRAM cell-controlled pass transistors. To reduce the signal delay in pass transistors, we proposed a scheme raising the gate-control voltage to 7V. The designed SRAM cells have built-in shift register capability, so there is no need for separate shift registers. We designed SRAM cells in the LUTs(look-up tables) to enable the wirte operations to be performed synchronously with the clock for ease of system application. Each logic block (LFU) has four 4-input LUTs, flip-flops and other gates, and the LUTs can be used a sSRAM memory. The LFU also has a dedicated carry logic, so a 4-bit adder can be implemented in one LFU. We designed our FPGA using 0.6.mu.m CMOS technology, and simulation shows proper operation of a 4 bit counter at 100MHz.

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Norfloxacin이 담지된 Poly(ε-caprolactone)/Poly(ethylene glycol) 이중블록공중합체 미셀의 제조 (Norfloxacin-Incorporated Polymeric Micelle Composed of Poly(ε-caprolactone)/Poly(ethylene glycol) Diblock Copolymer)

  • 정영일;장미경;나재운
    • 폴리머
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    • 제33권2호
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    • pp.137-143
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    • 2009
  • 이 연구에서 norfloxacin(NFX)이 담지된 poly($\varepsilon$-caprolactone)/poly(ethylene glycol)(PCL/PEG, abbreviated as CE) 이중블록공중합체로 구성된 고분자 미셀을 제조하였다. 입자크기는 PCL블록길이에 따라 60$\sim$200 nm사이였다. 임계회합농도는 소수성 PCL 블록길이가 증가함에 따라 감소하는 경향을 보였다. $^1H$-NMR 연구에서 PCL 블록은 내핵, PEG는 외피를 형성한 미셀구조로 형성되었음을 확인하였다. 약물의 방출은 약 2일간 지속되었으며 PCL블록길이와 약물함량이 증가함에 따라 감소하는 경향을 보였다. 항미생물 성능 실험에서 고분자 미셀은 기존의 NFX와 비슷한 독성을 보였다.

H.264 표준에서 가중된 다중 참조 블록을 이용한 효율적인 VLC 표 예측 방법 (An Efficient VLC Table Prediction Scheme for H.264 Using Weighting Multiple Reference Blocks)

  • 허진;오관정;호요성
    • 대한전자공학회:학술대회논문집
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    • 대한전자공학회 2005년도 추계종합학술대회
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    • pp.39-42
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    • 2005
  • H.264, a recently proposed international video coding standard, has adopted context-based adaptive variable length coding (CAVLC) as the entropy coding tool in the baseline profile. By combining an adaptive variable length coding technique with context modeling, we can achieve a high degree of redundancy reduction. However, CAVLC in H.264 has weakness that the correct prediction rate of the variable length coding (VLC) table is low in a complex area, such as the boundary of an object. In this paper, we propose a VLC table prediction scheme considering multiple reference blocks; the same position block of the previous frame and the neighboring blocks of the current frame. The proposed algorithm obtains the new weighting values considering correctness of the VLC table for each reference block. Using this method, we can enhance the prediction rate of the VLC table and reduce the bit-rate.

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