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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
21

Novel Methods for Primality Testing and Factoring

Hammad, Yousef Bani January 2005 (has links)
From the time of the Greeks, primality testing and factoring have fascinated mathematicians, and for centuries following the Greeks primality testing and factorization were pursued by enthusiasts and professional mathematicians for their intrisic value. There was little practical application. One example application was to determine whether or not the Fermat numbers, that is, numbers of the form F;, = 2'" + 1 were prime. Fermat conjectured that for all n they were prime. For n = 1,2,3,4, the Fermat numbers are prime, but Euler showed that F; was not prime and to date no F,, n 2 5 has been found to be prime. Thus, for nearly 2000 years primality testing and factorization was largely pure mathematics. This all changed in the mid 1970's with the advent of public key cryptography. Large prime numbers are used in generating keys in many public key cryptosystems and the security of many of these cryptosystems depends on the difficulty of factoring numbers with large prime factors. Thus, the race was on to develop new algorithms to determine the primality or otherwise of a given large integer and to determine the factors of given large integers. The development of such algorithms continues today. This thesis develops both of these themes. The first part of this thesis deals with primality testing and after a brief introduction to primality testing a new probabilistic primality algorithm, ALI, is introduced. It is analysed in detail and compared to Fermat and Miller-Rabin primality tests. It is shown that the ALI algorithm is more efficient than the Miller-Rabin algorithm in some aspects. The second part of the thesis deals with factoring and after looking closely at various types of algorithms a new algorithm, RAK, is presented. It is analysed in detail and compared with Fermat factorization. The RAK algorithm is shown to be significantly more efficient than the Fermat factoring algorithm. A number of enhancements is made to the basic RAK algorithm in order to improve its performance. The RAK algorithm with its enhancements is known as IMPROVEDRAK. In conjunction with this work on factorization an improvement to Shor's factoring algorithm is presented. For many integers Shor's algorithm uses a quantum computer multiple times to factor a composite number into its prime factors. It is shown that Shor's alorithm can be modified in a way such that the use of a quantum computer is required just once. The common thread throughout this thesis is the application of factoring and primality testing techniques to integer types which commonly occur in public key cryptosystems. Thus, this thesis contributes not only in the area of pure mathematics but also in the very contemporary area of cryptology.
22

Vyhodnocení plodnosti raka signálního včetně post-ovulačního stavu vaječníků

FOJT, Martin January 2018 (has links)
The theoretical part of diploma thesis is aimed at breeding, growth and molting events in crayfish. Thesis is also aimed at life cycle and reproduction of three indigenous crayfish species (Astacus astacus, Austropotamobius torrentium, Pontastacus leptodactylus) and two introduced crayfish species (Faxonius limosus, Pacifastacus leniusculus). The results show apparent linear dependence between female size (POCL), abdomen surface (1M: y = -1061,2 + 65,4*x; r2 = 0,9829; p10-5; 2M: y = -1160,4 + 68,7*x; r2 = 0,8732; p < 10-5) and fertility (1M: y = -194,4 + 12,8*x; r2 = 0,4104 p = 0,0042; y = -330.9 + 15,9*x; r2 = 0.4372; p < 10-4) in once (1M) and twice (2M) molted females. As the length of carapax increase, the area of the abdomen increase and fertility increase in both groups of females. Furthermore, the differences in fertility, carapax length, abdomen surface, and weights in once and twice molted females of signal crayfish. In group of once molted females fertility (t-test, t = -3.12, p = 0.003), carapax length (t-test, t = -3.17, p = 0.003) = -3.24; p = 0.002) and the weight (t-test, t = -3.35; p = 0.002) was higher than in twice molted group of female. Consequentially evaluation of egg size of females. The size of the eggs did not differ between groups of females (1M and 2M) (t-test, t = -0.975, p = 0.335). The mean egg size for both groups of females was 2.71 ? 0.18 mm. Evaluation of post-ovulation conditions of the ovary, including visible signs of females that resorbed unovulated oocytes. Evaluating how much unovulated oocytes were found in the ovaries. Only in 46.4% of the total number of females were ovaries completely empty. In once and twice molted females were found in average 2.2 ? 3.8 and 1.9 ? 2.6. unovulated oocytes, respectively. In once molted, three females didn't lay eggs, two females lost the clutch of eggs. In twice molted females, six females did not lay the eggs and four females lost the clutch.
23

塔信政權與泰國政治變遷 / Thaksin's regime and political change in Thailand

張靜尹, Chang, Chin Yin Unknown Date (has links)
本文擬探討塔信政權與泰國政治變遷的關係,從兩方面來分析泰國政黨政治體系的改變,一是從制度面討論1997年憲法的選舉制度對泰國政黨政治的衝擊與影響。二是從憲法的實踐和非制度化因素,分析塔信政權之興起與終結,來觀察泰國政治變遷的過程與意義。塔信政權是在1997年憲法下所運作的產物,最後卻被長達15年不見的軍事政變所終結。本文深入剖析塔信政權執政過程,探討為何會發生軍事政變的原因,以及分析這(場政變)對泰國民主產生什麼樣的意義與影響。 / This study examines the relationship between Thaksin's regime and political change in Thailand. It analyzes the change of the Thai party system from two respects. First, it discusses the impact which the new electoral system of the 1997constitution had on the Thai party politics. Second, it analyzes the rise and the fall of Thaksin’s regime from the constitution practice and the non-institutional factors in order to observe the process and the implication of political change in Thailand. Thaksin’s regime is the result of 1997 constitution. However, it was ended by a military coup which had not happened for 15 years. We discuss deeply the history of Thaksin’s regime, why the military coup took place to close this regime, and the influence of this military coup on Thai democracy.
24

Využití pitev bezobratlých živočichů ve výuce biologie na středních školách / Usage of dissection of invertebrate animals in education of biology at secondary school

Ondrová, Radka January 2013 (has links)
The thesis is focused on anatomy and implementation of dissections of 4 selected model invertebrates in school practice. The selected model species include swan mussel (Anodonta cygnea), stick insect (Medauroidea extradentata), cockchafer (Melolontha melolontha) and sea urchin (Echinus esculentus). In case of the cockchafer, the text is based on this model species, but the supporting photographs of dissection are taken from the tropical cetoniid beetle Pachnoda, which has very similar internal anatomy with the cockchafer. For all selected animals, I describe external and internal morphology as well as recommended methods of obtaining the material, proper killing of specimens, and dissection techniques. The text is supplemented with original digital macrophotographs. The thesis includes also an overview of primary and secondary school textbooks with focus on anatomy of the selected animals. The text is supplemented by a glossary of morphological terminology used in this thesis. Attached is a photographic atlas of dissections, which is a combination of this master thesis and my bachelor thesis (defended in 2010), in which I dealt with five model invertebrates in the same way. This is Ascaris suum, Lumbricus terrestris, Helix pomatia, Procambarus aff. fallax and Archimandrita tesselata. The complete...

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