Thesis (PH. D.)--University of Chicago, 1911. / "Extracted from Carnegie institution of Washington. Publication no. 161." Includes bibliographical references.

Important characteristic of any VLSI design circuit is its power reliability, high operating speed and low silicon area implementation. Dynamic CMOS designs provide high operating speeds compared to static CMOS designs combined with low silicon area requirement. The use of pipelines can also provide high circuit operating speeds. However, as the operating frequency increases, the number of pipeline stages should also increase and so the memory elements. These memory elements increases the area of implementation and restricts the maximum achievable frequency due to their delays. Memoryless pipelines based on dynamic design address these issues but, still requires high power consumption for the clock signal. In this thesis we present a sinusoidal three-phase clocking scheme that reduces the power required by the clock and offers high circuit operating frequencies. Thus the proposed technique provides advantages over preexisting techniques in terms of power requirement, area over head and operating speed.

[No abstract available] / Science, Faculty of / Mathematics, Department of / Graduate

The threespine stickleback (Gasterosteus aculeatus L.) is a highly varied and widely distributed species of small fish. Throughout most of its range there are two distinct forms. One form (trachurus) is anadromous and the other form (leiurus) is sedentary and lives entirely in fresh water. Hagen (1967) concluded that these two forms were re productively isolated and that both leiurus and trachurus should be considered as species. Hagen's conclusion was based on differences he found in ecological habitats, breeding times, and the apparent absence of introgression between, leiurus and trachurus. The purpose of this study was to determine if ethological factors or mate selection contribute to reproductive isolation. Mate selection tests were conducted in which (1) courting males were simultaneously exposed to receptive females of both types, and (2) receptive females were simultaneously exposed to both types of courting males. The results of both these tests clearly demonstrate that matings between similar phenotypes occur significantly more often than matings between dissimilar phenotypes. Additional experiments attempt to document the specific behavioural mechanisms responsible for mate selectivity. The orientation of males to females, and females to males, was observed and quantified. Males were found to orient, or direct most of their courtship, to females of their own phenotype. Females also tended to orient to males of their own phenotype. Certain behavioural patterns of male courtship were quantified and compared between leiurus and trachurus. Significant differences were found in a number of courtship activities: leiurus males perform significantly more zig-zags per minute than trachurus males, the first courtship response of leiurus males is usually a zig-zag while the first response of trachurus males is usually a bite. Non-random mating between leiurus and trachurus may contribute greatly to their reproductive isolation. Non-random or selective mating may be explained by difference in behaviour between the two forms, particularly during courtship. / Science, Faculty of / Zoology, Department of / Graduate

Let f(z) be a complex-valued function of the complex variable z which is regular at the origin, has radius of convergence R > 1 , and satisfies the condition f(1) = 1 . If we write [ equation omitted ]and [ equation omitted ], n=0,1,2,..., the matrix [ equation omitted ] leads to a summation method generally known as a Sonnenschein method. The utility of these methods lies in the fact that much can be said about them simply from a knowledge of the function f(z) . In the present work we are concerned with the three methods associated with the three functions f(z) = (1-r) + rz , f(z) = (1-r)+rz² and f(z) = (1-r)z + rz³ where r≠ 0 is an arbitrary complex parameter (generally, 0 < r < 1). The method based on the function (1-r) + rz leads to the well-known Euler-Knopp method which has already been extensively studied. We show that there exist simple recursion relations between the various rows of the matrix F and we make a detailed study of the domain Dᵣ on which these methods sum the geometric series [ equation omitted ].A more general sub-class of Sonnenschein methods called the (E,r,α,β) methods is then defined and some of the well-known theorems applicable to the (E,r) method are shown to hold for this sub-class. The practical application of the above three methods to the two- and three-body problems of classical mechanics forms the major portions of Chapters II and III . Much use is made in these chapters of a theorem, stated in Chapter I , which allows us to construct a domain Dr(a) on which one of the above methods sums an arbitrary function a(z) regular at the origin. On the limited Intervals for which the above methods are applicable, it is shown that they provide effective methods for obtaining the solution to the two-and three-body problems. Comparison is always made with similar results obtained by V. A. Brumberg and it is shown that the methods used here have certain advantages over his. The Sundman series for the three-body problem are also set up and utilized. Although the series are not very effective, the convergence is not as bad as is generally supposed. An interesting argument based on numerical evidence shows that the width of the strip about the real axis, in which the solution to the regularized three-body problem is known to be analytic, is not as narrow as Sundman's estimates give. Finally, a theorem is proved for the problem of the motion of a heavy rigid body about a fixed point showing that this problem can be treated in the complex plane in the same way as the two-body problem and regularized three-body problem. / Science, Faculty of / Mathematics, Department of / Graduate

Design and fabrication of three-dimensional (3D) ICs is one the newest and hottest trends in semiconductor manufacturing industry. In 3D ICs, multiple 2D silicon dies are stacked vertically, and through silicon vias (TSVs) are used to transfer power and signals between different dies. The electrical characteristic of TSVs can be modeled with equivalent circuits consisted of passive elements. In this thesis, we use “dummy” TSVs as electrical delay units in 3D SRAMs. Our results prove that dummy TSVs based delay units are as effective as conventional delay cells in performance, increase the operational frequency of SRAM up to 110%, reduce the usage of silicon area up to 88%, induce negligible power overhead, and improve robustness against voltage supply variation and fluctuation.

This recommended "time planner" has been included so that you have some idea of how much time you will need for each of the lessons. One of the aims of this package is to ensure that teachers do not have to deviate more than is necessary from their normal Std 8 lessons on the structure and function of cells. However, teachers are asked to include the following introductory exercises when they teach the section on the cell. Please emphasis strongly (to the pupils) that this is NOT extra work irrelevant to the syllabus. These lessons are to assist them to develop skills which are absolutely essential for them to succeed as biology scholars. Thereafter the teaching is left to the teacher. However, teachers are asked to incorporate the worksheets on cell organelles. and other relevant exercises, into those lessons in which they deal with those organelles. As teachers will realise. the active involvement of pupils in the learning task inevitably means that more time is spent teaching that section of work. Thus some of the tasks are for pupils to complete at home. Teachers are asked to ensure that pupils do complete these exercises, and that they have some sort of follow-up in class, even if it is merely a class display of drawings which have been done

No description available.

In this thesis, the design of a voltage-source inverter (VSI)-based three-phase impedance analyzer's perturbation injection unit (PIU) is described including all relevant power stage and control design. Both series and shunt injection are examined from .1 Hz to 1000Hz. Both types of injection are performed using only energy from the system under test stored in a DC link capacitor. Sinusoidal, square (pulse), and chirp perturbation waveforms are explored. Results from a constructed realization of the design are presented, and the limits of the device characterized. The maximum achievable perturbation power is 10 kW in shunt and 8 kW in series on a 460 V, 100 kW bus. Using the same conditions, maximum power is achievable from 10Hz to 100Hz, at .1Hz, .72 kW is achievable, and at 1000Hz, 6.0 kW is achievable. / Master of Science

University of Macau / Faculty of Science and Technology. / Department of Computer and Information Science