Browsing by Subject "Performance"

This dissertation concerns the optimization of the aeroelastic performance of conventional

helicopter rotors, considering various design variables such cyclic and higher

harmonic controls. A nite element model is introduced to model the structural

eects of the blade, and a coupled induced velocity/projected force model is used

to couple this structural model to the aerodynamic model constructed in previous

works. The system is then optimized using two separate objective functions: minimum

power and minimum vibrational loading at the hub. The model is validated

against several theoretical and experimental models, and good agreement is demonstrated

in each case. Results of the rotor in forward

ight demonstrate for realistic

advance ratios the original lifting surface model is sucient for modeling normalized

induced power. Through use of the dynamics model the vibrational loading minimization

is shown to be extremely signicant, especially when using more higher

harmonic control. However, this decrease comes at an extreme cost to performance

in the form of the normalized induced power nearly doubling. More realistic scenarios

can be created using multi-objective optimization, where it is shown that vibrational

loading can be decreased around 60% for a 5% increase in power.

The value of task-related conflict to team effectiveness continues to generate controversy in organizational studies. I argue that this debate reflects as much differences in the conceptualization of conflict by scholars from separate traditions as it does variation in empirical settings and methods. The model proposed in this research is a more general framework for the study of team conflict that clarifies, accommodates, and reconciles to a large degree the divergent findings of prior research. It suggests that recent pessimism about the value of team conflict is overstated, and it offers a number of promising paths through which task-related conflict may improve team performance and satisfaction. Chapter 1 reviews the history of this debate and introduces the model of team conflict. Chapter 2 documents a test of the model's propositions in a correlational study of 223 MBA teams conducting a decision-making exercise. Chapter 3 features an experimental test of the model with a forecasting task completed by 60 3-person groups. And Chapter 4 revisits the conflict over conflict in light of the studies presented herein.

Bodily Trespass situates the fantastic as a discourse of spatial production in twentieth-century black American literature. Eruptions of the fantastic in realist and surrealist narratives index and ameliorate the spatial constriction that informs black American subjectivity from the Middle Passage up through to the contemporary carceral state. The black fantastic is a narrative response to a spatial crisis that is corporeal and ontological. As a literary mode, in the Todorovian sense, the fantastic identifies the real as a production of the "unreal" and calls attention to ideological and institutional apparatuses that sustain the dominant order. Taking Pauline Hopkins' turn of the twentieth-century serial Of One Blood, Or, The Hidden Self as a point of departure, this project examines the fantastic as a discourse of Pan-Africanism during a period Farah Griffin describes as the "nadir" of post-emancipation black life. Hopkins reaches outside of U.S. borders suturing Ethiopia to America in order to fashion a new and "rival" black geography that challenges the eradication of black legal, civic, and social space.

In the postwar years, the production of imaginative space extends to the task of recording and refuting the racial discourse that articulates urbanity. Chester Himes' The Real Cool Killers, Ann Petry's The Street, and Gwendolyn Brooks' Maud Martha depict racially encoded urban geographies as corporeally informed psychosocial "interfaces." These novels identify cartographic locution as a strategy for spatial occupation and psychic rehabilitation. James Baldwin's "Sonny's Blues" and Ralph Ellison's "The King of the Bingo Game locate in the sonic a blueprint for refashioning the space of the modern metropolis according to a logic of interiority. Baldwin and Ellison identify the fantastic as a discourse of aurality that alters the texture of space by channeling what I call "scalar consciousness," a heightened awareness of the ways in which one might manipulate scale in the service of spatial production. Meditations on belonging, displays of corporeal violence, discourses of Africanity, and the identification of the aural as a pathway for liberation illustrate, in all these works, the black fantastic's rootedness in spatial production, subject formation, and resistance to a dehumanizing social order.

This dissertation explores the relationship between identity and place in the imagination, performance and production of post-World War II Puerto Rican urban space in Chicago. Specifically, I contend that the articulation of Puerto Rican spatiality in the city has emerged primarily as a response to the threat of local displacement as a byproduct of urban renewal and gentrification. I further argue the experience of displacement, manifested through territorial attachment, works to deepen the desire for community and belonging. Through a performance and cultural studies approach, this project works to track this recent history of Puerto Rican geographic and psychic displacement within Chicago as it is evidenced by various performative spatial interventions and manifested within the community's expressive culture.

My topics of study include the 1966 Division Street Riots, the Young Lords Organization (YLO), Humboldt Park's Paseo Boricua and spoken-word poet David Hernández. Through these interventions and forms of expression, I argue that physical, political, discursive, and affective claims are made to local territory, articulating a Puerto Rican cultural identity inextricably connected to urban space. In so doing, I aim to endorse the theoretical utility of concepts of "space" by highlighting the enduring material and metaphoric significance of place for Puerto Ricans, arguing against a tendency in contemporary Puerto Rican studies to equate circular migratory movement with transnationalism by virtue of its opposition to territorially grounded definitions of identity.

Background: Maternal and congenital syphilis are pressing concerns in Latin America, with consequences ranging from newborn mental retardation to perinatal death. Widespread, accurate screening and timely penicillin treatment can help. Simple, affordable, point of care rapid syphilis tests (RSTs) promise to improve screening coverage among pregnant women.

Methods: From September 2009 to November 2010, Project CISNE implemented the SD Bioline Syphilis 3.0 RST into two health networks, offering the test to pregnant women aged 16 55 who attended antenatal care, delivery/postpartum, and abortion services. The performance analysis compared Bioline RST results with reference standards TPPA and RPR+TPPA, adjusting estimates according to sampling realities.

Results: 17,147 rapid syphilis tests were performed in the field and 11,169 were screened in the central laboratory. Syphilis prevalence was 1.05% (0.73% adjusted) according to the gold standard vs. 0.90% according to the field RST. The Bioline RST displayed an unadjusted sensitivity of 91.0% (95% CI 86.4 95.0) and specificity of 99.1% (98.1 99.6) compared to TPPA, and an unadjusted sensitivity of 91.5% (84.8 95.8) and specificity of 99.6% (99.4 99.7) compared to RPR+TPPA. When adjusted, overall sensitivity and specificity compared to RPR+TPPA were 86.5% (78.8 92.0) and 99.7% (99.6 99.8), respectively. The Bioline RST yielded more false positive than false negative results due to the observed low prevalence.

Discussion: Despite limitations, this study displays the field RST to be reliable, reproducible, as valid as previous studies, and diagnostically apt for implementation in maternal care services in Peru.

Entering the information age, the demands for online services increase dramatically. Such high demands are pushing the network systems to become more complex and making system availability a crucial requirement for both service providers and clients. The service providers are aiming to have an effective, efficient and stable service: the service should be failure resilient, be scalable to support a large group of clients and still keep acceptable performance. Whereas the clients need a “powerful” service – high performance without threats to their privacy or security. To this end, huge efforts have been made to improve the service availability issues, to detect failures, to overcome the failures introduced by bugs and scalability problems, or to provide a strong guarantee of performance, effectiveness and security. We explore the system availability problem with several network scenarios including Software Defined Networks, Data Center Networks and Cable Networks, and propose new concepts to further improve networking services’ availability.

This dissertation documents African-American girls' musical practices at a Boys and Girls Club in Durham, NC. Hip-hop is the cornerstone of social exchanges at John Avery, and is integrated into virtually all club activities. Detractors point to the misogyny, sexual exploitation and violence predominant in hip-hop's most popular incarnations, suggesting that the music is a corrupting influence on America's youth. Girls are familiar with these arguments, and they appreciate that hip-hop is a contested and sometimes illicit terrain. Yet they also recognize that knowledge about and participation in hip-hop-related activities is crucial to their interactions at the club, at school, and at home. As girls hone their listening skills, they reconcile the contradictions between behavior glorified by hip-hop and the model presented to them by their mentors. This project examines how African-American girls ages 5-13 use their listening practices to claim a space within hip-hop's landscape while still operating within the unambiguous moral framework they have learned from their parents, mentors and peers. Through ethnography and close analysis of vocal utterances, dance moves and social interaction, I consider how individual interactions with mass-mediated music teach girls a black musical aesthetic that allows them to relate to their peers and mentors, and how these interactions highlight the creativity with which they begin to negotiate sexual and racial politics on the margins of society.

This dissertation examines the intersection of experimental art, literature, performance, photography, and architecture, as Japanese artists and intellectuals grappled with political disillusionment after the end of the protests against the ratification of the U.S.-Japan Security Treaty of 1960. I focus on the work of the sculptors Miki Tomio and Kudo Tetsumi; photographs of late 1960s protests by Tomatsu Shomei and the self-portraits of the novelist Mishima Yukio; the collaboration between photographer Hosoe Eikoh and butoh dance founder Hijikata Tatsumi in the photo album Kamaitachi (The Sickle-Weasel, 1969); and depictions of the urban periphery in Hosoe's unfinished Private Landscape series (1970-) and the visionary urban planning of the architect Tange Kenzo. All shared an interest in portraying peripheral spaces, the detritus of the everyday, and the sexually perverse, cultivating a rhetoric of marginality that allowed them to explore their ambivalent feelings towards post-Anpo Japan.

This dissertation explores and theorizes the work of American artist Matthew Barney through the concept of deadpan, and situates it in relation to themes of hybridity and animality in parallel histories of sculpture, performance art, and film.

This dissertation contends that sound and aurality ought to be more fully integrated into how gender and sexuality are thought. The dissertation’s title, “Partial Figures,” refers to its aims: not to exhaustively document the status of sound within discourses of sexual difference and dissidence, but rather to sketch how queer and feminist thought might draw on sound’s resources. The project is thus situated within the longer trajectory of visual approaches to power and gender. “Partial Figures” also describes what I suggest are sound and aurality’s specific erosion of the figure as a presumptive requirement of approaches to social life and aesthetic form. By partial, I mean both incomplete and nonunitary, subject to the decay and growth, the putative disfigurement, that Hortense Spillers describes under the rubric of flesh. Finally, the notion of being partial, as opposed to impartial, is also at play. Partiality -- having a weakness for something – describes an orientation that bridges affection and dependency or debility; it compromises aesthetics as a site for the exercise of judgement. To be partial to something or someone is to be rendered incomplete by that thing, a torsion or disfigurement that marks queer and feminist method. By considering notions of musical flavor and corporeality (Chapter 1), queer sound ecologies (Chapter 2), and gendered ontologies of frequency and vibration (Chapter 3), I revisit key conceptual knots within theories of gender and sexuality that require a more sustained attention to sound and aurality.

I focus on two fundamental preoccupations within queer and feminist scholarship that, I argue, are reconfigured by the methodological, material, and historical resources of sound: corporeality (Chapter 1) and ecology (Chapter 2). From this assessment of sound’s essential resources for theories of gender and sexuality, Chapter 3 then moves, through a consideration of sexual difference as noise, to suggest that sonic ontologies likewise cannot properly be thought without queer and feminist method.

The first chapter concerns corporeality as a principal site of feminist theory’s turn to questions of matter and affect in the 2000s. For some influential theorists, I argue, an ambiguous and overdetermined relationship between food, fatness, and “epidemic” debility became a cipher for the specifically causative or agential powers of matter and affect. I show, however, that these powers have already been thought otherwise in the overlapping contexts of black studies and musicology. I take up notions of musical flavor and culinary sound in the work of Fred Moten and Theodor Adorno, respectively, alongside Hortense Spillers’ account of ungendered flesh as resisting figuration in the sense of both embodiment and (ac)counting. Like fatness, musical flavor is felt as the distension and elaboration of form and enjoyment, its aesthetic and figural enrichments taken for a failure to budget and apportion pleasure, need, and dependency. Within feminism’s turn toward corporeal matter, I argue, fatness and food have been made to serve as both a hinge and an impasse. On the one hand, the purported links between eating, fatness, and debility have been taken as the very image of self-evident causation. On the other hand, however, fatness troubles etiology, generating endless (and to date, inconclusive) speculation about what causes it and how its alleged social pathology might be reversed. Its status as a site of commingled growth and purported decay, life and “premature” death or debility, has presented itself to some writers as an apparent conundrum. In addition to Moten, Adorno, and Spillers, I draw on critiques of causality by Denise Ferreira da Silva and Michel Foucault. The nonopposition of growth and decay, life and debility, enjoyment and dependency, emerges through music and artworks by Future, UGK, Anicka Yi, Alvin Lucier, and Constantina Zavitsanos, among others.

Chapter 2 concerns a second historically vexed site for thinking gender and sexuality: nature and ecology. I approach the relation between sex, ecology, and sound through one of queer theory’s founding preoccupations: “public,” outdoor, or undomestic sexual gathering. “Public sex” has been imagined as a question of sightlines and their obstruction, but I argue that its sociality is given form by acoustics and acute sensitivity to environmental sound in spaces where visual obscurity offers both protection and danger. I read the 1998 album Second nature: an electro-acoustic pastoral, produced from field recordings of a parkland cruising ground by the group Ultra-red, who develop an audio ecology of this queer sexual commons alongside a critique of the pastoral as a site of musical and ecological containment. Works by Samuel Delany, Simon Leung, June Jordan, Park McArthur, Lorraine O’Grady, TLC, and others situate Ultra-red’s Second nature within an understanding of a sexual commons that views need and dependency as forms of ecological wealth.

Chapter 3 considers noise as a figure for feminine sexual difference, suggesting that ontologies of sound must be conditioned by queer and feminist thought. My argument proceeds through an account of chatter, frequency, and perpetual motion, considering Drake’s “Hotline Bling,” chatbots, gifs, David Lynch’s 2006 film Inland Empire, consciousness-raising, and the work of artists Jessica Vaughn, Amber Hawk Swanson, and Pauline Oliveros. Questions of frequency and vibration have emerged as part of sonic ontologies in recent years; I trace the entry of vibration and “vibes” into U.S. popular discourse in the early 20th century through the theological and musicological writing of Sufi Inayat Khan. Among his areas of influence, I focus on the history of modern dance, particularly its Orientalist preoccupation with the animated wave-forms of loose fabric, which was demonstrably molded by Khan’s theories of vibration. This racially and sexually marked “signature” gesture was the subject of several intellectual property lawsuits that sustained legal ambiguity about the status of performance as property.

Inter-Vehicle Communication (IVC) is a vital part of Intelligent Transportation System (ITS), which has been extensively researched in recent years. Dedicated Short Range Communication (DSRC) is being seriously considered by automotive industry and government agencies as a promising wireless technology for enhancing transportation safety and efficiency of road utilization. In the DSRC based vehicular ad hoc networks (VANETs), the transportation safety is one of the most crucial features that needs to be addressed. Safety applications usually demand direct vehicle-to-vehicle ad hoc communication due to a highly dynamic network topology and strict delay requirements. Such direct safety communication will involve a broadcast service because safety information can be beneficial to all vehicles around a sender. Broadcasting safety messages is one of the fundamental services in DSRC. In order to provide satisfactory quality of services (QoS) for various safety applications, safety messages need to be delivered both timely and reliably. To support the stringent delay and reliability requirements of broadcasting safety messages, researchers have been seeking to test proposed DSRC protocols and suggesting improvements. A major hurdle in the development of VANET for safety-critical services is the lack of methods that enable one to determine the effectiveness of VANET design mechanism for predictable QoS and allow one to evaluate the tradeoff between network parameters. Computer simulations are extensively used for this purpose. A few analytic models and experiments have been developed to study the performance and reliability of IEEE 802.11p for safety-related applications. In this thesis, we propose to develop detailed analytic models to capture various safety message dissemination features such as channel contention, backoff behavior, concurrent transmissions, hidden terminal problems, channel fading with path loss, multi-channel operations, multi-hop dissemination in 1-Dimentional or 2-Dimentional traffic scenarios. MAC-level and application-level performance metrics are derived to evaluate the performance and reliability of message broadcasting, which provide insights on network parameter settings. Extensive simulations in either Matlab or NS2 are conducted to validate the accuracy of our proposed models.

The visual representation of Indigenous North American peoples in contemporary visual culture continues to rely on romanticized images drawn from early twentieth century salvage ethnography surveys, presenting Indigenous American nations as part of the continent’s storied past while denying their active presence in contemporary society. This dissertation explores a body of conceptual art photography, created between the 1990’s and the present, that responds uniquely to the persistence of romantic ethnographic visual tropes. Focusing on the work of artists who are members of Native American nations situated within the United States, this study explores the relationships among anthropological visual conventions, Western philosophies defining what it means to be human, Western academic theories of photography, and settler-colonial history in North America. It delves specifically into the links between the foundations of anthropological visualities and later twentieth century theory positing the photographic image as a mode of death, popularized by scholars including Roland Barthes, Susan Sontag, and Martha Rosler, among others. I consider how the contemporary artists addressed intervene in these theoretical discourses of photography by way of interjecting elements of performance into photography. I identify and analyze strategies including the appropriation and physical manipulation of historic images; a reimaging of the photographic act; performative interventions into the still image; the use of satire and affect; Indigenous Futurisms; storytelling; and a radical collapsing of the boundaries between performance action and photography.

This project traces the seemingly improbable intersections between performances of blackness and the development and traces of an American liberalism defined by Gunnar Myrdal's overwhelmingly influential, sociological text, An American Dilemma. I argue that when Myrdal determined in his 1944 study on the "Negro problem" that the messy inconsistencies between how the United States articulated its laudable egalitarianism and the violent histories of oppression defining the lives of African Americans was a matter resting in the "hearts and minds of white America" rather than entrenched structural inequalities, he enabled a radicalized version of sentimentality that would structure how liberalism attempted to rectify this racial paradox right into the 21st century - to walk in someone else's skin rather than their shoes. While American liberalism is a notoriously contested and slippery set of ideologies, the texts I study provide a performative logic of American liberalism that deconstructs and historicizes its own ideological impulses around notions of racial difference.

The project situates the discursive legacies of Myrdal's study alongside a series of spectacularized narratives of what I call "racial im/posture" - adventures in racial impersonation authorized by American liberalism and reliant on the logics of both blackface minstrelsy and racial passing. I consider these narratives of racial im/posture in the literary genres of memoir, autobiography, fiction, and speculative fiction, along with the legal brief, the film, and the photograph. Although I read these seemingly disparate texts from my own epistemological disciplining of literary studies, the methodology employed here is an interdisciplinary one indebted to performance and visual studies, race and queer theory, as well as new Southern studies. The project intervenes in the conventional thinking around racial masquerade by reframing the temporality of what has largely been considered an issue of the 19th and early 20th centuries as well as by considering these texts through the anxieties, ironies, and contentions of the discursive legacies of American liberalism. In five chapters that satellite around the ideological apparatuses of our sociopolitical and cultural landscape including social and literary fictions, the law, and transnational capital, I think through issues of authenticity, belonging, community, appropriation, and performance.