Variable-Length Coding with Cost Allowing Non-Vanishing Error Probability

We derive a general formula of the minimum achievable rate for fixed-to-variable length coding with a regular cost function by allowing the error probability up to a constant $\varepsilon$. For a fixed-to-variable length code, we call the set of source sequences that can be decoded without error the dominant set of source sequences. For any two regular cost functions, it is revealed that the dominant set of source sequences for a code attaining the minimum achievable rate with a cost function is also the dominant set for a code attaining the minimum achievable rate with the other cost function. We also give a general formula of the second-order minimum achievable rate.Comment: 7 pages; extended version of a paper accepted by ISITA201

ブロック符号に対する置換生成行列を用いた最尤復合アルゴリズムの計算量低減に関する研究

制度:新 ; 文部省報告番号:甲2129号 ; 学位の種類:博士(工学) ; 授与年月日:2005/12/22 ; 早大学位記番号:新412

Improved Rate-Equivocation Regions for Secure Cooperative Communication

A simple four node network in which cooperation improves the information-theoretic secrecy is studied. The channel consists of two senders, a receiver, and an eavesdropper. One or both senders transmit confidential messages to the receiver, while the eavesdropper tries to decode the transmitted message. The main result is the derivation of a newly achievable rate-equivocation region that is shown to be larger than a rate-equivocation region derived by Lai and El Gamal for the relay-eavesdropper channel. When the rate of the helping interferer is zero, the new rate-equivocation region reduces to the capacity-equivocation region over the wire-tap channel, hence, the new achievability scheme can be seen as a generalization of a coding scheme proposed by Csiszar and Korner. This result can naturally be combined with a rate-equivocation region given by Tang et al. (for the interference assisted secret communication), yielding an even larger achievable rate-equivocation region.Comment: 18 pages, 5 figure

Biological Antioxidant Potential Negatively Correlates with Carotid Artery Intima-Media Thickness

学位記番号：医博乙140