Approved for public release; distribution is unlimited / This report discusses the theory, design, implementation and testing of a personal computer-based Multi-Frequency Modulation (MFM) packet communications system. Transmitter/receiver programs provide software drivers for D/A and A/D boards and perform symbol encoding, modulating, demodulating and decoding. The design and construction of a polarity coincidence correlator for receiver packet synchronization is presented. Experimental results show that the implemented MFM communication system conforms to theoretical analysis with acceptable bit error. Results also show the MFM can be uniquely adapted to a specific channel. / http://archive.org/details/implementationof00gant / Lieutenant, United States Navy

Gases at satisfactory pressures fluoresce in the presence of radio frequency radiation (6). Such fluorescent gases have been used to probe fields of radio frequency oscillation and their emission spectra have been recorded and studied. Ions with multiple charges also exist in these gases, (6). In 1941 Oliver (12) observed the fluorescence of an isobutane- isobutene gaseous mix flowing to a pump through a glass tube which was wrapped by a spiral antenna of a sevenmegacycle transmitter. A white deposit was noticed at a bend in the tubing on the pump side of the fluorescing section of the gas (12, p. 8). In 1957 Blacknall (3) studied the fluorescence and reaction products of propylene in the antenna region of sevenmega- cycle radiation, The oscillator employed by Blacknall was an ARC-5/T-22 military surplus transmitter of range 7.00 to 9.10 megacycles, which he operated at 7.00 megacycles. Blacknall observed a drop in pressure and the formation of a brown deposit in the region of the coil. Blacknall did not report an analysis of this product. In 1959 Armstrong (1) repeated Blacknall's experiments and modified Blacknall's apparatus into an improved design. He also performed an analysis on Blacknall's product. Blacknall used a vertical open-end mercurial manometer with which to measure pressure in his system and as a result introduced mercury vapor into his system. Armstrong tried to minimize the amount of mercury introduced by covering his manometric mercury with a layer of octyl sebacate, "octoil". Armstrong used a spiral-would antenna wrapped around his reaction vessel and reported the formation of spiral brown rings coincident with the copper wire of the antenna. There was a white product deposited in a spiral interlaced with the spiral of dark brown material. No definite identification was reported by Armstrong other than reporting, his solid material as isotactic polypropylene. Other work on electrodeless discharge of organic chemicals has been done in 1960 by Durward Smith and William Smith (13), in 1961 by Jimmie McCarty (10), and in 1963-64 by David Flinn (4).

M.Phil. (Electrical and Electronic Engineering) / There are two methods that can be used when power is converted from one frequency to another. One way uses a DC link as an intermediate stage and the other uses no intermediate stage. When no DC link exists, the conversion process is referred to as AC-AC conversion, (Cha, Enjeti & Ratanapanachote, 2004:2237). This method essentially chops the AC signal in a specific manner which yields an AC signal with a different frequency directly. Depending on how the AC signal is chopped, it would result in a varied number of wave shapes are constructed. The construction of these various wave shapes results in devices that can accomplish different tasks. One such device is called a unity displacement factor frequency converter (UDFFC). This research attempts to develop a model, to simulate and design a unity displacement factor frequency converter. The primary idea about this device is that the power factor or displacement factor is unity regardless of the load. There are three parts in the development of the UDFFC. The power circuit is an array or matrix of switches that link the three phase supply to the three phase load. The power circuit is interfaced to the control circuit which generates pulses that control the matrix of switches. The control circuit utilizes embedded control software that performs the control logic in a microcontroller. The development of the UDFFC has a potential to solve real power engineering problems, such as eliminating the DC link in a converter. This achieves the conversion of AC directly to AC in the absence of a DC link. The other major advantage is the variation of the output frequency to a desired value. The most important is that the displacement factor can be controlled as well.

M.Ing. / Photovoltaic (PV) systems are considered as renewable resources of energy that are utilized in the conversion of direct and diffuse solar radiation to electric power. These systems are considered as environmentally friendly energy resources as they reduce pollution. These systems’ produced power depends on the radiation of the sun as well as the temperature, the impedance of the load, and the unfitted parameters in PV systems. In this field, the PV systems and DC-DC converters will be explored in both configuration (the open loop and closed loop systems), whilst their implementation will be designed as a closed loop system. The success of the system depends on the algorithm of the maximum power point tracking that catches the maximum sunshine radiation amount to generate the maximum electrical power. This system simulation and hardware implementation will be done through the Proteus program and real components integration ...

Acoustical analyses have been utilized to ascertain the functional status of the laryngeal mechanism for clinical management of communication disorders (Gilbert and Weismer, 1974). In particular, the modal frequency level (MFL), defined as the fundamental frequency most often used by an individual in the act of spontaneous speech (Travis, 1971), is one measurement used to determine if a person's pitch level is adequate. Two other pitch measurements used in the voice assessment are the maximum frequency range (MFR) and the optimum pitch level (OPL). Information is needed to provide guidelines for pitch levels as part of the voice evaluation for adult females of different ages. It is not clear from the literature if there is a statistically significant MFL difference between White female nonsmokers and cigarette smokers as determined by different phonatory tasks. The purpose of this investigation was to compare the MFLs of nonsmoking and cigarette smoking White females between the ages of forty and fifty years. The primary research question was: Does smoking significantly affect the modal frequency level of forty to fifty year old White females as compared with forty to fifty year old White females who do not smoke?

No description available.

The recent demand for wireless transceivers has created a flurry of research into nontraditional receiver architectures. The homodyne receiver, because of its high degree of integration, low complexity and low power consumption, has surfaced a desirable alternative to the well-known heterodyne receiver. However, distortions such as gain and phase imbalance severely degrade the performance of the homodyne receiver. These imbalances, which are caused by impairments of the employed analog devices, are intensified because quadrature demodulation is performed at very high frequencies with a weak input signal. Thus, there exists a great need for low complexity techniques to compensate for these imbalances. In this thesis, we present a new, simplified method for the estimation and the correction of the gain and phase imbalances in a homodyne receiver. The estimation process is based upon carrier re-injection during idle periods of the mobile unit and thus requires only few additional analog components. This approach will be shown to yield tight estimates of the gain and the phase error. Additionally, the correction is performed in the digital domain and thus can be implemented on a digital signal processor. The effectiveness of this method is demonstrated via simulations of an IS-54 transceiver. IS-54 is the North American TDMA standard for dual-mode cellular systems. / Graduation date: 1998

Thesis (M.S.)--Montana State University--Bozeman, 2006. / Typescript. Chairperson, Graduate Committee: James P. Becker. Includes bibliographical references (leaves 120-121).

This research investigates the performance of an existing structural damage detection method (SDIM) when only experimentally-obtained measurement information can be used to calculate the frequency response functions used to detect damage. The development of a SDIM that can accurately identify damage while processing measurements containing realistic noise levels and overcoming experimental modeling errors would provide a robust method for identifying damage in the larger, more complex structures found in practice. The existing SDIM program, GaDamDet, uses an advanced genetic algorithm, along with a two-dimensional finite element model of the structure, to identify the location and the severity of damage using the linear vibration information contained in frequency response functions (FRF) as response signatures. Datagen is a Matlab program that simulates the three-dimensional dynamic response of the four-story, two-bay by two-bay UBC test structure built at the University of British Columbia. The dynamic response of the structure can be obtained for a range of preset damage cases or for any user-defined damage case. Datagen can be used to provide the FRF measurement information for the three-dimensional test structure. Therefore, using the FRF measurements obtained from the UBC test structure allows for a more realistic evaluation of the performance of the SDIM provided by GaDamDet as the impact on performance of more realistic noise and model errors can be investigated. Previous studies evaluated the performance of the SDIM using only simulated FRF measurements obtained from a two-dimensional structural model. In addition, the disparity between the two-dimensional model used by the SDIM used to identify damage and the measurements obtained from the three-dimensional test structure is analyzed. The research results indicate that the SDIM is able to accurately detect structural damage to individually damaged members or to within a damaged floor, with few false damages identified. The SDIM provides an easy to use, visual, and accurate algorithm and its performance compares favorably to performance of the various damage detection algorithms that have been proposed by researchers to detect damage in the three-dimensional structural benchmark problem.

In 2011, Internet users spent almost 23% of their time on social media sites such as Twitter and Facebook. Twitter alone was estimated to have over 200 million active users. With social media being such a popular online pastime, a tremendous amount of information becomes available from the posts that users put on social media sites. This information has the potential to reveal details about the social media users, such as the relationship between characteristics of the users and what they post. This relationship is a hot research topic and one of the most frequently studied characteristic is the gender of a user. Feature frequency is often included in such a task, but this thesis shows that for Twitter tweets it either does not contribute significantly to gender classification or hinders classification. / McAnulty College and Graduate School of Liberal Arts; / Computational Mathematics / MS; / Thesis;