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This dissertation is a case study of the Irish Echo, an Irish ethnic weekly newspaper that began publishing in New York City in 1928. The Irish ethnic community is unique because it operates within two cultural spheres: Irish society and American society. The purpose of this case study is to identify how ethnic newspaper function and how this function has changed over time. The study attempts to explain the role of the ethnic newspaper in balancing the needs of immigrants to adapt to American culture while maintaining ties to their native country. The author uses a qualitative approach combining oral history, in depth interviewing, documentary evidence and textual analysis. The study finds that the Irish Echo acts as a functional intersect that provides adhesion and structure through the operations of bonding and bridging. It performs these functions through political advocacy, vocal criticism of discrimination, and guides in assimilation and character building. / Mass Media and Communication

In the modern era of wireless communications, radios are becoming increasingly more cognitive. As the complexity and robustness of friendly communications increases, so do the abilities of adversarial jammers. The potential uses and threats of these jammers directly pertain to fourth generation (4G) communication standards, as well as future standards employing similar physical layer technologies. This paper investigates a number of threats to the technologies utilized by 4G and future systems, as well as potential improvements to the security and robustness of these communications systems. The work undertaken highlights potential attacks at both the physical layer and the multiple access control (MAC) layer along with improvements to the technologies which they target. This work presents a series of intelligent, targeted jamming attacks against the orthogonal frequency division multiplexing (OFDM) synchronization process to demonstrate some security flaws in existing 4G technology, as well as to highlight some of the potential tools of a cognitive electronic warfare attack device. Performance analysis of the OFDM synchronization process are demonstrated in the presence of the efficient attacks, where in many cases complete denial of service is induced. A method for cross ambiguity function (CAF) based OFDM synchronization is presented as a security and mitigation tactic for 4G devices in the context of cognitive warfare scenarios. The method is shown to maintain comparable performance to other correlation based synchronization estimators while offering the benefit of a disguised preamble. Sync-amble randomization is also discussed as a combinatory strategy with CAF based OFDM synchronization to prevent cognitive jammers for tracking and targeting OFDM synchronization. Finally, this work presents a method for dynamic spectrum access (DSA) enabled radio identification based solely on radio frequency (RF) observation. This method represents the framework for which both the cognitive jammer and anti-jam radio would perform cognitive sensing in order to utilize the intelligent physical layer attack and mitigation strategies previously discussed. The identification algorithm is shown to be theoretically effective in classifying and identifying two DSA radios with distinct operating policies. / Ph. D.

The focus of this dissertation is the performance analyses of two classes of frequency-hopped spread-spectrum multiple access (FH-SSMA) systems in various fading environments. The capacity of Viterbi’s FH-SSMA system is evaluated under three types of fading, namely Rician, shadowed Rician, and Nakagami fading. The results of recent experiments have indicated that these fading phenomena occur in various environments where the FH-SSMA system may be implemented. In this dissertation, the deletion probability for each fading scenario is derived. Subsequently, the system capacity is analyzed in terms of maximum number of users versus average bit error rate. The effect of a change in the signal-to-noise ratio level on the system capacity is also demonstrated. For Rician fading, it is found that the capacity of the system with a Rician factor of 2 dB is reduced by 13 percent as compared to the capacity of the non-fading case. For shadowed Rician fading, three shadowing scenarios are considered: light, average, and heavy. It is shown that the light and the average shadowing scenarios provide only a slight decrease in the capacity, while the heavy shadowing scenario renders a capacity identical to that for the Rayleigh fading case. Finally, for Nakagami fading the capacity is found to decrease by 50 percent as the fading parameter is reduced to 0.5. The performance of a cellular frequency-hopped spread-spectrum multiple access system is studied under an indoor environment. It is demonstrated how the system capacity, given in terms of the number of users per cell, is affected by the number of cells in the system. Also, the influence of the delay spread, which is the result of multipath propagation, is investigated. The analysis focuses on a worst-case scenario where a user receives both the desired and interfering signals with equal power levels. This scenario applies to both the downlink and the uplink. It is shown that the system capacity is reduced drastically as the number of adjacent interfering cells increases from one to three. Previous work concerning the indoor multipath propagation assumed that the number of paths is fixed, the path delays are uniformly distributed, and the path gains are equal. In this dissertation, a more realistic channel model derived from actual impulse response measurements by Saleh and Valenzuela is employed. The model consists of clusters of rays with constant cluster and ray arrival rates and power-delay time constants. The system performance is shown to be affected strongly by the change in the power-delay time constants, yet only slightly influenced by the variation in the arrival rates of the rays and clusters. In addition, the degradation in the system performance due to the delay spread becomes more severe as the transmission rate increases. / Graduate

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