Analysis of a modified variable-length tuning post in a rectangular waveguide.

A modified variable-length post for use in high power waveguide tuning networks is analyzed to determine its reactance properties. Theoretical predictions are shown to be in good agreement with experimental results. An investigation of the reactance characteristics and the aperture voltage characteristics of the modified post, as a function of its dimensions, is also reported.     

Transient response improvement of feedback control systems using hybrid reference control

By means of the internal model principle, an approach to improve the performance of a stabilised closed-loop continuous time linear system based on manipulation of the reference signal is developed. A change in the reference signal is equivalent to implementing an instantaneous change via the choice of a decision vector in the state of the reference signal model, and the analysis of the proposed approach called hybrid reference control (HRC) system is then shown to be equivalent to the analysis of a linear impulsive dynamical system. Conditions for asymptotic stability and convergence of the output tracking error for a HRC system are expressed in term of conditions on the decision vectors. Conditions are then derived which guarantee that the HRC system leads to an improved transient performance compared to a conventional closed-loop control system. In particular, it is shown how decision vectors are chosen so that a HRC system results in a deadbeat response.     

An adaptive IIR filter algorithm based on observers

The output error approach to adaptive IIR filtering is considered from a state observation perspective, and a new algorithm, termed the observer-based regressor filtering (OBRF) algorithm, is developed. The convergence requirements of the OBRF are established as a persistent excitation condition on the regressor and a strict positive reality (SPR) condition on an operator arising in the algorithm. Speed of convergence experiments show that the OBRF algorithm converges more quickly than the related output error algorithm for the hyperstable adaptive recursive filter (HARF), although the OBRF algorithm converges as quickly as typical equation error schemes. The OBRF is shown to compare favorably with equation error with respect to parameter bias in the presence of output measurement noise. Thus, OBRF is a compromise between the equation error and output error approaches. In addition, algorithm parameter selection to satisfy the SPR condition for OBRF is explored and compared with the related conditions for HARF     

T-Equivalent Circuit Parameters of a Variable-Length Cylindrical Post in a Rectangular Waveguide

A simple expression for the series reactance of a solid variable-length cylindrical post in a rectangular waveguide is determined from an approximate field analysis. Results are shown to be in excellent agreement with experimental measurements. When used in conjunction with an existing analysis for determining the shunt reactance, it is shown that accurate results can be calculated for the complete T-equivalent circuit.     

Mobile radio propagation in Auckland at 851 MHz

A series of field trials undertaken in Auckland at 851 MHz have shown that the median propagation loss may be estimated by the plane earth propagation loss plus a clutter factor of 45.1, 27.0, 21.7 and 18.3 dB for urban, light urban, suburban and rural environments, respectively.     

Effects of progesterone intravaginal devices on synchronization of estrus in postpartum dairy cows

Effects of two intravaginal treatments of progesterone on the synchronization of behavioral estrus were compared in three groups of lactating dairy cows at 7 to 8 wk postpartum. Group 1 had progesterone-releasing intravaginal devices with attached estradiol benzoate capsules inserted for 12 d. Groups 2 and 3 had controlled internal drug release devices, containing progesterone alone, inserted for 9 or 12 d. Behavioral estrus was detected as early as 24, 32, and 36 h after removal of the devices in groups 1, 2, and 3, respectively. Estrus was better synchronized and the proportion of cows showing estrus after device removal was greater in group 1 than in groups 2 and 3. After removal of devices, mean milk progesterone of all cows that did not show estrus was higher than that of cows that showed estrus. In groups 1, 2, and 3, 1 of 7, 7 of 12, and 4 of 12 cows not showing estrus had high milk progesterone after removal of the devices, indicating the presence of functional corpora lutea. In cows not displaying estrus milk progesterone concentrations decreased, indicating these cows were cyclic, although behavioral estrus was absent.     

Bulimia and depression: A review of the affective variant hypothesis.

Bulimia is a disorder characterized by binge eating, purgative behavior, and depressed mood following eating binges. Repeated empirical demonstrations of the pervasive quality of the depressive symptomatology characterizing bulimia have led some researchers to hypothesize that bulimia is an affective disorder variant, that is, a form of affective disorder, as opposed to a separate diagnostic entity. In this article, we review the literature related to this hypothesis and evaluate its validity. We conclude that it is premature to hypothesize that bulimia is an affective variant. An alternative hypothesis is that bulimia, like many other chronic disorders, is often accompanied by depression. Such a hypothesis denies neither the significance of the depression experienced by people suffering from bulimia nor the unique aspects of the eating disorder. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Including Women? (Dis)junctures Between Voice,Policy and Implementation in Integrated Development Planning

Integrated development plans (IDPs) are municipal strategic plans designed to bring about developmental local government. They have been criticised for providing insufficient space for democratic participation. This paper explores the extent to which a marginalised group—women—has been incorporated into the IDP process, in response to three questions. First, how have IDP participatory processes incorporated women’s voice, and are the new participatory spaces realising their transformative potential? Secondly, how have women’s interests and a gender perspective been mainstreamed in the IDP, and has it promoted transformation? And finally, at the interface between officials and women themselves, how are IDP projects implemented and does agency promote or impede the goals of gender equality? A study of three KwaZulu-Natal municipalities reveals some achievements, but unequal gender relations have not been transformed. These case studies demonstrate some of the complexities and difficulties in the practice of democratic governance.     

Molecular typing of Streptococcus uberis strains isolated from cases of bovine mastitis

The discriminatory power of two polymerase chain reaction-based DNA fingerprinting methods, random amplified polymorphic DNA and repetitive extragenic palindrome were compared by subtyping 128 isolates of Streptococcus uberis cultured from cows in six different dairy herds in New Zealand. The typing results demonstrated that the majority of isolates possessed unique fingerprint profiles except on occasions where multiple isolates were obtained from individual cows. On these occasions, individual quarters of the mammary gland were generally, but not exclusively, infected by the same strain of bacteria. Both random amplified polymorphic DNA and repetitive extragenic palindromic typing assays were simple to perform, relatively inexpensive ($11.00 per reaction), and provided reliable and reproducible results. Furthermore, when these assays were used in conjunction with each other, they provided a means of confirmation of the specific DNA fingerprint patterns obtained.