Investigated the properties of LUCas sequence(LUC), the paper proposed a new variant of (probabilistic) public-key encryption scheme. Security analysis of the proposed encryption schemes shows that its one-wayness is ...Investigated the properties of LUCas sequence(LUC), the paper proposed a new variant of (probabilistic) public-key encryption scheme. Security analysis of the proposed encryption schemes shows that its one-wayness is equivalent to partial LUC discrete logarithm problem in ZN, and for the proposed probabilistic encryption scheme, its semantic security is equivalent to decisional LUC Diffie-Hellman problem in ZN. At last, the efficiency of the proposed schemes is briefly analyzed.展开更多
The QR Code is a 2 dimensional matrix code with high error correction capability. It employs RS codes to generate error correction codewords in encoding and recover errors and damages in decoding. This paper presents ...The QR Code is a 2 dimensional matrix code with high error correction capability. It employs RS codes to generate error correction codewords in encoding and recover errors and damages in decoding. This paper presents several QR Code’s virtues, analyzes RS decoding algorithm and gives a software flow chart of decoding the QR Code with RS decoding algorithm.展开更多
Android, an open source system exploited by Google, has experienced a rapid development in the past a few years in the field of intelligent mobile because of its advantages-open source and excellent function. The numb...Android, an open source system exploited by Google, has experienced a rapid development in the past a few years in the field of intelligent mobile because of its advantages-open source and excellent function. The number of professionals and enthusiasts who research on Android is growing rapidly in the same time. Android, as an abstraction between software layer and hardware layer based on Linux kernel, can complete the optimization of system by modifying the kernel part. The purpose of this design is to master the processes of kernel-compiling and transplanting, and to learn the methods of memory scheduling algorithm and kernel menaory test. First of all, this thesis introduces the installation of Linux system, and then, it presents the method to build the environment for Android kernel compiling and the process of compiling. The key point of the design is to introduce the SLAB, SLOB, SLUB, SLQB allocators in memory scheduling, and carry on a research on optimization with these memory allocators. HTC Incredible S, as an experimental mobile phone whose Android kernel version is 2.6.35, is employed to deal with all these tests. A comparison of kernel codes before and after optimization has been made. The two kernel codes have been transplanted into the terminal of the experimental mobile phone, which will be respectively tested with its stability, memory performance and overall performance. Finally, it concludes that result of being transplanted the SLQB memory allocator is the optimal one of all.展开更多
In this paper,a novel dual-metric,the maximum and minimum Squared Euclidean Distance Increment (SEDI) brought by changing the hard decision symbol,is introduced to measure the reli-ability of the received M-ary Phase ...In this paper,a novel dual-metric,the maximum and minimum Squared Euclidean Distance Increment (SEDI) brought by changing the hard decision symbol,is introduced to measure the reli-ability of the received M-ary Phase Shift Keying (MPSK) symbols over a Rayleigh fading channel. Based on the dual-metric,a Chase-type soft decoding algorithm,which is called erased-Chase algorithm,is developed for Reed-Solomon (RS) coded MPSK schemes. The proposed algorithm treats the unre-liable symbols with small maximum SEDI as erasures,and tests the non-erased unreliable symbols with small minimum SEDI as the Chase-2 algorithm does. By introducing optimality test into the decoding procedure,much more reduction in the decoding complexity can be achieved. Simulation results of the RS(63,42,22)-coded 8-PSK scheme over a Rayleigh fading channel show that the proposed algorithm provides a very efficient tradeoff between the decoding complexity and the error performance. Finally,an adaptive scheme for the number of erasures is introduced into the decoding algorithm.展开更多
基金Supported by the 973 State Key Project of China (No.G1999035803)the National Natural Science Foundation of China (No.69931010).
文摘Investigated the properties of LUCas sequence(LUC), the paper proposed a new variant of (probabilistic) public-key encryption scheme. Security analysis of the proposed encryption schemes shows that its one-wayness is equivalent to partial LUC discrete logarithm problem in ZN, and for the proposed probabilistic encryption scheme, its semantic security is equivalent to decisional LUC Diffie-Hellman problem in ZN. At last, the efficiency of the proposed schemes is briefly analyzed.
文摘The QR Code is a 2 dimensional matrix code with high error correction capability. It employs RS codes to generate error correction codewords in encoding and recover errors and damages in decoding. This paper presents several QR Code’s virtues, analyzes RS decoding algorithm and gives a software flow chart of decoding the QR Code with RS decoding algorithm.
文摘Android, an open source system exploited by Google, has experienced a rapid development in the past a few years in the field of intelligent mobile because of its advantages-open source and excellent function. The number of professionals and enthusiasts who research on Android is growing rapidly in the same time. Android, as an abstraction between software layer and hardware layer based on Linux kernel, can complete the optimization of system by modifying the kernel part. The purpose of this design is to master the processes of kernel-compiling and transplanting, and to learn the methods of memory scheduling algorithm and kernel menaory test. First of all, this thesis introduces the installation of Linux system, and then, it presents the method to build the environment for Android kernel compiling and the process of compiling. The key point of the design is to introduce the SLAB, SLOB, SLUB, SLQB allocators in memory scheduling, and carry on a research on optimization with these memory allocators. HTC Incredible S, as an experimental mobile phone whose Android kernel version is 2.6.35, is employed to deal with all these tests. A comparison of kernel codes before and after optimization has been made. The two kernel codes have been transplanted into the terminal of the experimental mobile phone, which will be respectively tested with its stability, memory performance and overall performance. Finally, it concludes that result of being transplanted the SLQB memory allocator is the optimal one of all.
基金the National Natural Science Foundation of China (No.60272057).
文摘In this paper,a novel dual-metric,the maximum and minimum Squared Euclidean Distance Increment (SEDI) brought by changing the hard decision symbol,is introduced to measure the reli-ability of the received M-ary Phase Shift Keying (MPSK) symbols over a Rayleigh fading channel. Based on the dual-metric,a Chase-type soft decoding algorithm,which is called erased-Chase algorithm,is developed for Reed-Solomon (RS) coded MPSK schemes. The proposed algorithm treats the unre-liable symbols with small maximum SEDI as erasures,and tests the non-erased unreliable symbols with small minimum SEDI as the Chase-2 algorithm does. By introducing optimality test into the decoding procedure,much more reduction in the decoding complexity can be achieved. Simulation results of the RS(63,42,22)-coded 8-PSK scheme over a Rayleigh fading channel show that the proposed algorithm provides a very efficient tradeoff between the decoding complexity and the error performance. Finally,an adaptive scheme for the number of erasures is introduced into the decoding algorithm.
