• 제목/요약/키워드: constant weight codes

검색결과 6건 처리시간 0.016초

ONE-HOMOGENEOUS WEIGHT CODES OVER FINITE CHAIN RINGS

  • SARI, MUSTAFA;SIAP, IRFAN;SIAP, VEDAT
    • 대한수학회보
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    • 제52권6호
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    • pp.2011-2023
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    • 2015
  • This paper determines the structures of one-homogeneous weight codes over finite chain rings and studies the algebraic properties of these codes. We present explicit constructions of one-homogeneous weight codes over finite chain rings. By taking advantage of the distance-preserving Gray map defined in [7] from the finite chain ring to its residue field, we obtain a family of optimal one-Hamming weight codes over the residue field. Further, we propose a generalized method that also includes the examples of optimal codes obtained by Shi et al. in [17].

THE t-WISE INTERSECTION OF RELATIVE THREE-WEIGHT CODES

  • Li, Xin;Liu, Zihui
    • 대한수학회보
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    • 제54권4호
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    • pp.1095-1110
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    • 2017
  • The t-wise intersection is a useful property of a linear code due to its many applications. Recently, the second author determined the t-wise intersection of a relative two-weight code. By using this result and generalizing the finite projective geometry method, we will present the t-wise intersection of a relative three-weight code and its applications in this paper.

고정 가중치 부호에 의한 복수 화상용 시각암호 (Visual Cryptography for Multi Images Using Constant Weight Codes)

  • 김미라;박상우;박지환
    • 한국정보보호학회:학술대회논문집
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    • 한국정보보호학회 1996년도 종합학술발표회논문집
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    • pp.261-271
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    • 1996
  • M.Naor와 A.Shamir의 시각암호는 기존의 비밀 분산법에서 분산/복호시 연산량이 많은 것과는 달리 인간의 시각에 의해서 직접 복호될 수 있는 방식이다. 본 논문에서는 시각암호의 화장 방식인 복수 화상을 숨기는 방식에서 숨기려는 비밀화상의 수가 증가함에 따라 share 크기가 기하 급수적으로 커지는 문제점을 해결하기 위하여 고정 가중치부호의 해밍 거리를 조정하여 share 크기를 줄이는 방법을 제안한다.

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A CONSTRUCTION OF TWO-WEIGHT CODES AND ITS APPLICATIONS

  • Cheon, Eun Ju;Kageyama, Yuuki;Kim, Seon Jeong;Lee, Namyong;Maruta, Tatsuya
    • 대한수학회보
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    • 제54권3호
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    • pp.731-736
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    • 2017
  • It is well-known that there exists a constant-weight $[s{\theta}_{k-1},k,sq^{k-1}]_q$ code for any positive integer s, which is an s-fold simplex code, where ${\theta}_j=(q^{j+1}-1)/(q-1)$. This gives an upper bound $n_q(k,sq^{k-1}+d){\leq}s{\theta}_{k-1}+n_q(k,d)$ for any positive integer d, where $n_q(k,d)$ is the minimum length n for which an $[n,k,d]_q$ code exists. We construct a two-weight $[s{\theta}_{k-1}+1,k,sq^{k-1}]_q$ code for $1{\leq}s{\leq}k-3$, which gives a better upper bound $n_q(k,sq^{k-1}+d){\leq}s{\theta}_{k-1}+1+n_q(k-1,d)$ for $1{\leq}d{\leq}q^s$. As another application, we prove that $n_q(5,d)={\sum_{i=0}^{4}}{\lceil}d/q^i{\rceil}$ for $q^4+1{\leq}d{\leq}q^4+q$ for any prime power q.

Effect of Kinetic Degrees of Freedom of the Fingers on the Task Performance during Force Production and Release: Archery Shooting-like Action

  • Kim, Kitae;Xu, Dayuan;Park, Jaebum
    • 한국운동역학회지
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    • 제27권2호
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    • pp.117-124
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    • 2017
  • Objective: The purpose of this study was to examine the effect of changes in degrees of freedom of the fingers (i.e., the number of the fingers involved in tasks) on the task performance during force production and releasing task. Method: Eight right-handed young men (age: $29.63{\pm}3.02yr$, height: $1.73{\pm}0.04m$, weight: $70.25{\pm}9.05kg$) participated in this study. The subjects were required to press the transducers with three combinations of fingers, including the index-middle (IM), index-middle-ring (IMR), and index-middle-ring-little (IMRL). During the trials, they were instructed to maintain a steady-state level of both normal and tangential forces within the first 5 sec. After the first 5 sec, the subjects were instructed to release the fingers on the transducers as quickly as possible at a self-selected manner within the next 5 sec, resulting in zero force at the end. Customized MATLAB codes (MathWorks Inc., Natick, MA, USA) were written for data analysis. The following variables were quantified: 1) finger force sharing pattern, 2) root mean square error (RMSE) of force to the target force in three axes at the aiming phase, 3) the time duration of the release phase (release time), and 4) the accuracy and precision indexes of the virtual firing position. Results: The RMSE was decreased with the number of fingers increased in both normal and tangential forces at the steady-state phase. The precision index was smaller (more precise) in the IMR condition than in the IM condition, while no significant difference in the accuracy index was observed between the conditions. In addition, no significant difference in release time was found between the conditions. Conclusion: The study provides evidence that the increased number of fingers resulted in better error compensation at the aiming phase and performed a more constant shooting (i.e., smaller precision index). However, the increased number of fingers did not affect the release time, which may influence the consistency of terminal performance. Thus, the number of fingers led to positive results for the current task.