Digital Commons Network^™

Watson Brake, A Middle Archaic Mound Complex In Northeast Louisiana, Joe W. Saunders, Rolfe D. Mandel, C. Garth Sampson, Charles M. Allen, E. Thurman Allen, Daniel A. Bush, James K. Feathers, Kristen J. Gremillion, C.T. Hallmark, H. Edwin Jackson, Jay K. Johnson, Reca Jones, Roger T. Saucier, Gary L. Stringer, Malcolm F. Vidrine

Faculty Publications

Middle Archaic earthen mound complexes in the lower Mississippi valley are remote antecedents of the famous but much younger Poverty Point earthworks. Watson Brake is the largest and most complex of these early mound sites. Wry extensive coring and stratigraphic studies, aided by 25 radiocarbon dates and six huninescence dates, show that minor earthworks were begun here at ca. 3500 B.C. in association with an oval arrangement of burned rock middens at the edge of a stream terrace. The full extent of the first earthworks is not yet known. Substantial moundraising began ca. 3350 B.C. and continued in stages until …

Open Access In Library And Information Science: Dlist 2005 Survey, A Scholarly Communication Study, Anita Coleman

Faculty Publications

D-Lib Magazine readers were invited to contribute to a study on scholarly communication behavior by completing the dLIST 2005 survey.

Politically Motivated Bar Discipline, James E. Moliterno

Faculty Publications

Bar discipline and admission denial have a century~long history of misuse in times of national crisis and upheaval. The terror war is such a time, and the threat of bar discipline has once again become an overreaction to justifiable fear and turmoil. Political misuse of bar machinery is characterized by its setting in the midst of turmoil, by its target, and by its lack of merit. The current instance of politically motivated bar discipline bears the marks of its historical antecedents.

Acoustic And Spectral Characteristics Of Young Children's Fricative Productions: A Developmental Perspective, Shawn L. Nissen, Robert Allen Fox

Faculty Publications

Scientists have made great strides toward understanding the mechanisms of speech production and perception. However, the complex relationships between the acoustic structures of speech and the resulting psychological percepts have yet to be fully and adequately explained, especially in speech produced by younger children. Thus, this study examined the acoustic structure of voiceless fricatives (/f, θ, s, ʃ/) produced by adults and typically developing children from 3 to 6 years of age in terms of multiple acoustic parameters (durations, normalized amplitude, spectral slope, and spectral moments). It was found the acoustic parameters of spectral slope and variance (commonly excluded from …

Moral Responsiveness And Discontinuity In Therapy: A Qualitative Study, Jason B. Whiting Phd, R. Scott Nebeker, Stephen T. Fife

Faculty Publications

Phenomenological qualitative methods were used to identify and describe moral elements in therapeutic relationships. Using the relational philosophy of E. Levinas (1961/1969, 1979/1987) as a base, data in which therapists and clients identified and described morally responsive experiences in therapy sessions were analyzed. These moments were often unexpected and included categories of surprise, interruption, willingness to change, and clarifications/repairs. Additional moral phenomena related to therapists' attitudes included asymmetrical indebtedness, attitude of serving, and tentativeness of diagnosis. Identified moments of moral responsiveness were frequently associated with clients' progress in therapy. This suggests that conceptually smooth and uninterrupted therapy may be less …

Dlist And Dl-Harvest: Open Access For Lis, Anita Coleman

Faculty Publications

This is a 30-slide presentation sponsored by the University of Arizona, School of Information Resources & Library Science, Library Student Organization (LSO) on Sept. 26, 2005 from 6 - 7:30 pm. This is essentially the story of DLIST from inception in 2002 and includes the establishment of an advisory board, the open access aggregator DL-Harvest in 2005, the unfolding of the goals, objectives and vision, and the people who have been involved including internships. The context of the Open Access movement is briefly explored. References and notes help increase understanding of the importance of open access and DLIST to LIS.

Ultracam Observations Of The Black Hole X-Ray Transient Xte J1118+480 In Quiescence, T. Shahbaz, V. S. Dhillon, T. R. Marsh, J. Casares, C. Zurita, P. A. Charles, C. A. Haswell, R. I. Hynes

Faculty Publications

We present high time-resolution multicolour observations of the quiescent soft X-ray transient XTE J1118+480 obtained with ULTRACAM. Superimposed on the double-humped continuum g′ - and i′ -band light curves are rapid flare events which typically last a few minutes. The power density spectrum of the light curves can be described by a broken power-law model with a break frequency at ∼2 mHz or a power-law model plus a broad quasi-periodic oscillation at ∼2 mHz. In the context of the cellular automaton we estimate the size of the quiescent advection-dominated accretion flow (ADAF) region to be ∼10 4 Schwarzschild radii, similar …

How Family Religious Involvement Benefits Adults, Youth, And Children And Strengthens Families, David C. Dollahite, Jennifer Y. Thatcher

Faculty Publications

A growing body of empirical research demonstrates that a family’s religious involvement directly benefits adults, children and youth in many ways. Divorce rates are lower and marital satisfaction and quality scores highest among religiously involved couples. Religious practices are linked with family satisfaction, closer father-child relationships, and closer parent-child relationships. There is less domestic violence among more religious couples and religious parents are less likely to abuse or yell at their children. Religious involvement promotes involved and responsible fathering and is associated with more involved mothering. Greater religiosity in parents and youth is associated with a variety of protective factors …

The Emergence Of The Social Brain Network: Evidence From Typical And Atypical Development, Mark H. Johnson, Richard Griffin, Gergely Csibra, Hanife Halit, Teresa Farroni, Michelle Dehaan, Leslie A. Tucker, Simon Baron-Cohen, John E. Richards

Faculty Publications

Several research groups have identified a network of regions of the adult cortex that are activated during social perception and cognition tasks. In this paper we focus on the development of components of this social brain network during early childhood and test aspects of a particular viewpoint on human functional brain development: “interactive specialization.” Specifically, we apply new data analysis techniques to a previously published data set of event-related potential ~ERP! studies involving 3-, 4-, and 12-month-old infants viewing faces of different orientation and direction of eye gaze. Using source separation and localization methods, several likely generators of scalp recorded …

Observational Constraints On Cool Disk Material In Quiescent Black Hole Binaries, R. I. Hynes, E. L. Robinson, M. Bitner

Faculty Publications

We consider current observational constraints on the presence of cool, optically thick disk material in quiescent black hole binaries, specifically focusing on a case study of the prototypical system A0620-00. Such material might be expected to be present theoretically but is usually claimed to make a negligible contribution at optical and IR wavelengths. The primary argument is based on measurements of the veiling of stellar photospheric absorption lines, in which it is assumed that the disk spectrum is featureless. We use simulated spectra to explore the sensitivity of veiling measurements to uncertainties in companion temperature, gravity, and metallicity. We find …

Impact Of Receive Amplifier Signal Coupling On Mimo System Performance, Michael A. Jensen, Matthew L. Morris

Faculty Publications

This paper uses a detailed model of multiple input multiple output (MIMO) systems to explore the impact of signal coupling in the receiver front end on communication capacity. The model is applied to assess the performance of a MIMO system with two transmit and receive antennas in a simulated multipath environment for different amplifier coupling levels. The results show that in practical scenarios where simple impedance matching techniques are used, the circuit coupling can reduce the signal-to-noise ratio at the receiver and therefore degrade the achievable MIMO capacity.

Providing End-Of-Life Care To Patients: Critical Care Nurses' Perceived Obstacles And Supportive Behaviors, Renea L. Beckstrand, Karin T. Kirchhoff

Faculty Publications

• Background Critical care nurses care for dying patients daily. The process of dying in an intensive care unit is complicated, and research on specific obstacles that impede delivery of end-of-life care and/or supportive behaviors that help in delivery of end-of-life care is limited.
• Objective To measure critical care nurses' perceptions of the intensity and frequency of occurrence of (1) obstacles to providing end-of-life care and (2) supportive behaviors that help in providing end-of-life care in the intensive care unit.
• Methods An experimental, posttest-only, control-group design was used. A national, geographically dispersed, random sample of members of the American Association of …

Paradox And The Consumption Of Authenticity Through Reality Television, Randall L. Rose, Stacy L. Wood

Faculty Publications

We position reality television within the broader category of consumer practices of authenticity seeking in a postmodern cultural context. The study draws on relevant perspectives from consumer research, literary criticism, sociology, and anthropology to argue that viewers of reality television encounter three elements of paradox in the process of constructing authenticity. The negotiation of each paradox exceeds the process of coping with or resolving their inherent contradictions to encompass the creation of new values. We argue that consumers blend fantastic elements of programming with indexical elements connected to their lived experiences to create a form of self-referential hyperauthenticity.

Superdirectivity In Mimo Systems, Michael A. Jensen, Matthew L. Morris, Jon W. Wallace

Faculty Publications

Multiantenna systems such as devices for multiple-input-multiple-output (MIMO) communication can theoretically use array superdirectivity to optimally exploit the propagation channel. In traditional analyses of MIMO systems, such superdirectivity is not observed due to the commonly applied constraint that limits the excitation current magnitudes. However, when an electromagnetically appropriate constraint on the power radiated by the array is applied, the computed capacity can include effects of transmit superdirectivity. A similar result occurs at the receiver for spatially colored noise. This paper formulates the MIMO system capacity under these circumstances and provides a framework for computing this capacity when the level of …

Static And Dynamic Obstacle Avoidance For Miniature Air Vehicles, Jeffery Brian Saunders, Brandon Call, Andrew Curtis, Randal W. Beard, Timothy W. Mclain

Faculty Publications

Small unmanned air vehicles are limited in sensor weight and power such that detection and avoidance of unknown obstacles during flight is difficult. This paper presents a low power low weight method of detection using a laser range finder. In addition, a rapidly-exploring random tree algorithm to generate waypoint paths around obstacles known a priori is presented, and a dynamic geometric algorithm to generate paths around detected obstacles is derived. The algorithms are demonstrated in simulation and in flight tests on a fixed-wing miniature air vehicle (MAV).

Slickcraft: The Quality Name In Boating, Geoffrey D. Reynolds

Faculty Publications

SlickCraft:  The Quality Name in Boating is an article concerning the history of the Slick Craft Boat Company (1954-1969) of Holland, Michigan, its acquisition in 1969 by AMF Corporation (American Manufacturing and Foundry) and subsequent founding of S2 Yachts, Inc. by its founder, Leon Slikkers in 1974.

Cooperative Reinforcement Learning Using An Expert-Measuring Weighted Strategy With Wolf, Kevin Cousin, Gilbert L. Peterson

Faculty Publications

Gradient descent learning algorithms have proven effective in solving mixed strategy games. The policy hill climbing (PHC) variants of WoLF (Win or Learn Fast) and PDWoLF (Policy Dynamics based WoLF) have both shown rapid convergence to equilibrium solutions by increasing the accuracy of their gradient parameters over standard Q-learning. Likewise, cooperative learning techniques using weighted strategy sharing (WSS) and expertness measurements improve agent performance when multiple agents are solving a common goal. By combining these cooperative techniques with fast gradient descent learning, an agent’s performance converges to a solution at an even faster rate. This statement is verified in a …

Embedded Slanted Grating Coupler For Vertical Coupling Between Fibers And Silicon-On-Insulator Planar Waveguides, Gregory P. Nordin, J. Jiang, B. Wang

Faculty Publications

We propose a compact and efficient grating coupler for vertical coupling between optical fibers and planar waveguides. A grating with a parallelogram shape is designed to be etched through the entire high-index waveguide core. The coupler is optimized using a microgenetic algorithm coupled with a two-dimensional finite-difference time-domain method. Simulations show that up to 75.8% coupling efficiency can be obtained between a single-mode fiber and a 240-nm-thick silicon-on-insulator planar waveguide.

Studies In The Dynamics Of Economic Systems, Christophe G. Giraud-Carrier, Kevin Seppi, Nghia Tran, Sean C. Warnick, W. Samuel Weyerman, R. Johnson

Faculty Publications

This paper demonstrates the utility of systems and control theory in the analysis of economic systems. Two applications demonstrate how the analysis of simple dynamic models sheds light on important practical problems. The first problem considers the design of a retail laboratory, where the small gain theorem enables the falsification of pricing policies. The second problem explores industrial organization using the equilibria of profit-maximizing dynamics to quantify the percentage of a firm’s profits due strictly to the cooperative effects among its products. This ”Value of Cooperation” suggests an important measure for both organizational and antitrust applications.

Recent Progress In Improving Low-Temperature Stability Of Infrared Thin-Film Interference Filters, B. Li, S. Y. Zhang, J. C. Jiang, D. Q. Liu, F. S. Zhang

Faculty Publications

The degeneration of performance of an optical thin-film interference filter associated with the change of temperature is not acceptable. In this letter, we report a new progress in improving low-temperature performance of infrared narrow-band filters by using Pb1-xGexTe initial bulk alloy with appropriate Ge concentration x. It can be found that there exists a critical temperature for the investigated narrow-band filter, at which the temperature coefficient of filter is exactly zero. Therefore, by means of controlling the composition in (Pb1-xGex) 1-yTey layers, the temperature coefficient of filter can be tunable at the designated low-temperature. In our present investigation, when temperature …

Toward Sequencing The Sorghum Genome: A U.S. National Science Foundation-Sponsored Workshop Report, Stephen Kresovich, Brad Barbazuk, Joseph A. Bedell, Andrew Borrell, C. Robin Buell, John Burke, Sandra Clifton, Marie-Michéle Cordonnier-Ptratt, Stan Cox, Jeff Dahlberg, John Erpelding, Theresa M. Fulton, Bob Fulton, Lucinda Fulton, Alan R. Gingle, C. Tom Hash, Yinghua Huang, David Jordan, Patricia E. Klein, Robert R. Klein, Jurandir Magalhaes, Richard Mccombie, Paul Moore, John E. Mullet, Peggy Ozias-Akins, Andrew H. Paterson, Kay Porter, Lee Pratt, Bruce Roe, William Rooney, Patrick S. Schnable, David M. Stelly, Mitchell Tuinstra, Doreen Ware, Ujwala Warek

Faculty Publications

Members of the worldwide sorghum (Sorghum spp.) community, including private sector and international scientists as well as community representatives from closely related crops such as sugarcane (Saccharum spp.) and maize (Zea mays), met in St. Louis, Missouri, on November 9, 2004, to lay the groundwork for future advances in sorghum genomics and, in particular, to coordinate plans for sequencing of the sorghum genome. Key developments that made this workshop timely included advances in knowledge of the sorghum genome that provide for the development of a genetically anchored physical map to guide sequence assembly and annotation, the …

Highly Water-Soluble Thermally Responsive Poly(Thiophene)-Based Brushes, Sreelatha S. Balamurugan, Grigor B. Bantchev, Yuming Yang, Robin L. Mccarley

Faculty Publications

(Figure Presented) A brush with success: Responsive brushes composed of poly(N-isopropylacrylamide) grafted onto a poly(thiophene) backbone display the highest water solubility ever reported for a neutral poly(thiophene) as well as temperature-dependent optical properties and water solubilities (see picture). The graft polymer exhibits shifts in the π-π* transition of the poly(thiophene) backbone near the collapse temperature of the poly(N-isopropylacrylamide) chains. © 2005 Wiley-VCH Verlag GmbH & Co. KGaA.

An Evaluation Of The Metabolic Syndrome In A Large Multi-Ethnic Study: The Family Blood Pressure Program, Aldi T. Kraja, D. C. Rao, Alan B. Weder, Thomas H. Mosley, Stephen T. Turner, Chao Agnes Hsiung, Thomas Quertermous, Richard Cooper, J. David Curb, Michael A. Province

Faculty Publications

Background: The Family Blood Pressure Program is an ongoing, NHLBI-sponsored, multi-center program to study the genetic determinants of high blood pressure. The goal of this particular study was to study patterns of metabolic syndrome (MetS) in four ethnic groups: African Americans, Caucasians, Hispanics, and Asians. Methods: A major part of participants in three networks GENOA, HyperGEN and SAPPHIRe were recruited mainly through hypertensive probands. MetS was defined as a categorical trait following the National Cholesterol Education Program definition (c-MetS). MetS was also characterized quantitatively through multivariate factor analyses (FA) of 10 risk variables (q-MetS). Logistic regression and frequency tables were …

Optimizing Transmission Time Of Scalable Coded Images In Peer-To-Peer Networks, Xiao Su, Rod Fatoohi, Tao Wang

Faculty Publications

In this paper, we study how to optimize image transmission time in peer-to-peer networks by considering the property of bitstreams generated by image coding algorithms. Images can be either scalable coded or nonscalable coded. Since transmission of nonscalable coded images is well understood, we focus on the transmission of scalable coded images in this paper.Because scalable coding embeds lower bit-rate bitstreams into higher bit-rate bitstreams, there exists a many-to-one relationship between supplying and requesting peers. When a requesting peer asks for an image coded in a particular bit rate, multiple peers with the same image but coded in different bit …

Effects Of Mutual Coupling On Interference Mitigation With A Focal Plane Array, Michael A. Jensen, Karl F. Warnick

Faculty Publications

A focal plane array feed of electrically small elements has been proposed as a means for achieving high sensitivity for radio astronomy applications in the presence of radio frequency interference (RFI). For a broadband system, mutual coupling effects become significant as the array element spacing becomes small relative to the electromagnetic wavelength. We present a theoretical framework for modeling the effects of mutual coupling and for determining the optimal multiport matching network between array elements and front-end transistor low-noise amplifiers for maximum signal-to-noise ratio (SNR). Numerical results are given for a model scenario including spillover and amplifier thermal noise and …

Design And Characterization Of A Dual-Stage, Thermally Actuated Nanopositioner, Neal B. Hubbard, Larry L. Howell

Faculty Publications

A nanopositioner is presented that has two stages for independent coarse and fine position control. Thermal microactuators operate both stages. The first stage includes a bistable mechanism: it travels 52 micrometers between two discrete positions. The second stage is mounted on the first stage and moves continuously through an additional 8 micrometers in the same direction as the first stage. Three approaches to the control of the second stage were evaluated in terms of accuracy and manufacturability, and one was selected for the design of the nanopositioner. The device was surface micromachined in a two-layer polysilicon process. Experiments were performed …

Model Checking For E-Business Control And Assurance, Bonnie B. Anderson, James V. Hansen, Paul B. Lowry, Scott L. Summers

Faculty Publications

Model checking is a promising technique for the verification of complex software systems. As the use of the Internet for conducting e-business extends the reach of many organizations, well-designed software becomes the foundation of reliable implementation of e-business processes. These distributed, electronic methods of conducting transactions place reliance on the control structures embedded in the transaction processes. Deficiencies in control structures of processes that support e-business can lead to loss of physical assets, digital assets, money, and consumer confidence. Yet, assessing the reliability of e-business processes is complex and time-consuming. This paper explicates how model-checking technology can aid in the …

Sex-Related Acoustic Changes In Voiceless English Fricatives, Shawn L. Nissen, Robert Allen Fox

Faculty Publications

This investigation is a comprehensive acoustic study of 4 voiceless fricatives (/f θ s ʃ/) in English produced by adults and pre-and postpubescent children aged 6-14 years. Vowel duration, amplitude, and several different spectral measures (including spectral tilt and spectral moments) were examined. Of specific interest was the pattern of normal development of the acoustic properties of fricatives and the nature of sex-specific patterns of fricative articulation in prepubescent children. Little evidence of amplitude or duration differences was found between speakers that was related to the sex of the speaker. However, significant sex-specific differences in fricative articulation were found in …

Decentralized Perimeter Surveillance Using A Team Of Uavs, Timothy Mclain, Randal W. Beard, Derek Kingston, Ryan S. Holt, David W. Casbeer

Faculty Publications

This paper poses the cooperative perimeter-surveillance problem and offers a decentralized solution that accounts for perimeter growth (expanding or contracting) and insertion/deletion of team members. By identifying and sharing the critical coordination information and by exploiting the known communication topology, only a small communication range is required for accurate performance. Simulation and hardware results are presented that demonstrate the applicability of the solution.

Magnetism In Semiconductors: A Dynamical Mean-Field Study Of Ferromagnetism In Ga1-Xmnxas, K. Aryanpour, J. Moreno, M. Jarrell, R. S. Fishman

Faculty Publications

We employ the dynamical mean-field approximation to perform a systematic study of magnetism in Ga1-xMnxAs. Our model incorporates the effects of the strong spin-orbit coupling on the J=32 GaAs valence bands and of the exchange interaction between the randomly distributed magnetic ions and the itinerant holes. The ferromagnetic phase transition temperature Tc is obtained for different values of the impurity-hole coupling Jc and of the hole concentration nh at the Mn doping of x=0.05. We also investigate the temperature dependence of the local magnetization and spin polarization of the holes. By comparing our results with those for a single band …