在水声通信中,扩频通信具有可靠性高、抗多径能力强等特点,适合于远程或低信噪比情况下的通信;但另一方面,由于其带宽利用率低加之水声信道带宽有限,通信系统的数据率将受到很大的限制。为了提高数据率,提出了一种正交M-ary/DS扩频方法...在水声通信中,扩频通信具有可靠性高、抗多径能力强等特点,适合于远程或低信噪比情况下的通信;但另一方面,由于其带宽利用率低加之水声信道带宽有限,通信系统的数据率将受到很大的限制。为了提高数据率,提出了一种正交M-ary/DS扩频方法,该方法将正交直接序列(DS)扩频与并行M-ary扩频结合在一起,能够显著提高水声通信系统的数据率与带宽利用率。经过湖上实验验证,该方法在25 km距离约0 dB的接收信噪比下,采用63、127长度G o ld序列并通过RAKE接收,分别实现了对480个符号的无误码传输,数据率为381.0 b its/s与220.5 b its/s,其带宽利用率与使用相同序列的直接序列扩频相比提高了约一个数量级。展开更多
There is almost no work on ancient Egypt in Taiwan since historians are logically interested in ancient China.Egyptologists either work on archeology or study papyrus and written texts found in pyramids and tombs,with...There is almost no work on ancient Egypt in Taiwan since historians are logically interested in ancient China.Egyptologists either work on archeology or study papyrus and written texts found in pyramids and tombs,without putting it in perspective with other civilizations,such as Greek civilization.Philippe Ariés’ global history offers innovative opportunities on the study of Egyptian mentalities.All traditional historical work aims to study an ancient society,a social class,but very few focuses on the individuals.The theses of Lucien Febvre,father of the notion of mentalities,allow the historical discipline to have access not only to the factual structures of societies but also to the mental structures of the individuals that compose it.This new approach raises a crucial question: What are Europe’s roots? Has the Egyptian heritage been underestimated?展开更多
In this paper, we develop novel non-sine functions, named hybrid-P-ary generalized bridge functions, based on the copy and shift methods. The generating algorithm of hybrid-P-ary generalized bridge functions is introd...In this paper, we develop novel non-sine functions, named hybrid-P-ary generalized bridge functions, based on the copy and shift methods. The generating algorithm of hybrid-P-ary generalized bridge functions is introduced based on the hybrid-P-ary generalized Walsh function＇s copy algorithm. The main property, product property, is also discussed. This function may be viewed as the generalization of the theory of bridge functions. And a lot of non-sine orthogonal functions are the special subset of these novel functions, The hybrid-P-ary generalized bridge functions can be used to search many unknown non-sine functions by defining different parameters.展开更多
Evolutionary computation （EC） is one of the fastest growing areas in computer science that solves intractable optimization problems by emulating biologic evolution and organizational behaviors in nature. To de- sign...Evolutionary computation （EC） is one of the fastest growing areas in computer science that solves intractable optimization problems by emulating biologic evolution and organizational behaviors in nature. To de- sign an EC algorithm, one needs to determine a set of algorithmic configurations like operator selections and parameter settings. How to design an effective and ef- ficient adaptation scheme for adjusting the configura- tions of EC algorithms has become a significant and promising research topic in the EC research community. This paper intends to provide a comprehensive survey on this rapidly growing field. We present a classification of adaptive EC （AEC） algorithms from the perspective of how an adaptation scheme is designed, involving the adaptation objects, adaptation evidences, and adapta- tion methods. In particular, by analyzing tile popula- tion distribution characteristics of EC algorithms, we discuss why and how the evolutionary state information of EC can be estimated and utilized for designing ef- fective EC adaptation schemes. Two AEC algorithms using the idea of evolutionary state estimation, includ- ing the clustering-based adaptive genetic algorithm and the adaptive particle swarm optimization algorithm are presented in detail. Some potential directions for the re- search of AECs are also discussed in this paper.展开更多
The orientation of the addition of 5-amino-3-benzylthio-1,2,4-triazole and its analogues (pyrazole) (1) with the aryl isocyanate can be directed by controlling the reaction temperature and one of the product, 5-amino-...The orientation of the addition of 5-amino-3-benzylthio-1,2,4-triazole and its analogues (pyrazole) (1) with the aryl isocyanate can be directed by controlling the reaction temperature and one of the product, 5-amino-1-arylaminocarbonyl-3-benzylthio-1,2,4-triazole (pyrazole) (2), can rearrange at 170C to another product, 5-arylureylene-3-benzylthio-1,2,4-triazole (pyrazole) (3). A plausible mechanism explanation for this rearrangement reaction was presented. It was suggested that the rearrangement reaction could be referred to the thermodynamics transposition leading to the predominant 5-arylureylene-3-benzylthio-1,2,4-triazole energy preferentially.展开更多
Ⅰ. INTRODUCTION At the 1978 ICM conference held in Helsinki, Ap?ry gave a proof of ζ(3)=Σ1/N^3 being irrational. For this purpose he introduced the numbers α_n (n≥0) defined by recurrence
文摘在水声通信中,扩频通信具有可靠性高、抗多径能力强等特点,适合于远程或低信噪比情况下的通信;但另一方面,由于其带宽利用率低加之水声信道带宽有限,通信系统的数据率将受到很大的限制。为了提高数据率,提出了一种正交M-ary/DS扩频方法,该方法将正交直接序列(DS)扩频与并行M-ary扩频结合在一起,能够显著提高水声通信系统的数据率与带宽利用率。经过湖上实验验证,该方法在25 km距离约0 dB的接收信噪比下,采用63、127长度G o ld序列并通过RAKE接收,分别实现了对480个符号的无误码传输,数据率为381.0 b its/s与220.5 b its/s,其带宽利用率与使用相同序列的直接序列扩频相比提高了约一个数量级。
文摘There is almost no work on ancient Egypt in Taiwan since historians are logically interested in ancient China.Egyptologists either work on archeology or study papyrus and written texts found in pyramids and tombs,without putting it in perspective with other civilizations,such as Greek civilization.Philippe Ariés’ global history offers innovative opportunities on the study of Egyptian mentalities.All traditional historical work aims to study an ancient society,a social class,but very few focuses on the individuals.The theses of Lucien Febvre,father of the notion of mentalities,allow the historical discipline to have access not only to the factual structures of societies but also to the mental structures of the individuals that compose it.This new approach raises a crucial question: What are Europe’s roots? Has the Egyptian heritage been underestimated?
基金This work was supported by the National Natural Science Foundation of China （Grant Nos. 69931050, 69972002 and 60372018）.
文摘In this paper, we develop novel non-sine functions, named hybrid-P-ary generalized bridge functions, based on the copy and shift methods. The generating algorithm of hybrid-P-ary generalized bridge functions is introduced based on the hybrid-P-ary generalized Walsh function＇s copy algorithm. The main property, product property, is also discussed. This function may be viewed as the generalization of the theory of bridge functions. And a lot of non-sine orthogonal functions are the special subset of these novel functions, The hybrid-P-ary generalized bridge functions can be used to search many unknown non-sine functions by defining different parameters.
文摘Evolutionary computation （EC） is one of the fastest growing areas in computer science that solves intractable optimization problems by emulating biologic evolution and organizational behaviors in nature. To de- sign an EC algorithm, one needs to determine a set of algorithmic configurations like operator selections and parameter settings. How to design an effective and ef- ficient adaptation scheme for adjusting the configura- tions of EC algorithms has become a significant and promising research topic in the EC research community. This paper intends to provide a comprehensive survey on this rapidly growing field. We present a classification of adaptive EC （AEC） algorithms from the perspective of how an adaptation scheme is designed, involving the adaptation objects, adaptation evidences, and adapta- tion methods. In particular, by analyzing tile popula- tion distribution characteristics of EC algorithms, we discuss why and how the evolutionary state information of EC can be estimated and utilized for designing ef- fective EC adaptation schemes. Two AEC algorithms using the idea of evolutionary state estimation, includ- ing the clustering-based adaptive genetic algorithm and the adaptive particle swarm optimization algorithm are presented in detail. Some potential directions for the re- search of AECs are also discussed in this paper.
基金Project supported by the National Natural Science Foundation of China and the Natural Science Foundation of Tianjin.
文摘The orientation of the addition of 5-amino-3-benzylthio-1,2,4-triazole and its analogues (pyrazole) (1) with the aryl isocyanate can be directed by controlling the reaction temperature and one of the product, 5-amino-1-arylaminocarbonyl-3-benzylthio-1,2,4-triazole (pyrazole) (2), can rearrange at 170C to another product, 5-arylureylene-3-benzylthio-1,2,4-triazole (pyrazole) (3). A plausible mechanism explanation for this rearrangement reaction was presented. It was suggested that the rearrangement reaction could be referred to the thermodynamics transposition leading to the predominant 5-arylureylene-3-benzylthio-1,2,4-triazole energy preferentially.
文摘Ⅰ. INTRODUCTION At the 1978 ICM conference held in Helsinki, Ap?ry gave a proof of ζ(3)=Σ1/N^3 being irrational. For this purpose he introduced the numbers α_n (n≥0) defined by recurrence
