Showing papers by "University of North Carolina at Charlotte published in 1995"

The pseudospectral Legendre method for discretizing optimal control problems

Abstract: This paper presents a computational technique for optimal control problems including state and control inequality constraints. The technique is based on spectral collocation methods used in the solution of differential equations. The system dynamics are collocated at Legendre-Gauss-Lobatto points. The derivative x/spl dot/(t) of the state x(t) is approximated by the analytic derivative of the corresponding interpolating polynomial. State and control inequality constraints are collocated at Legendre-Gauss-Lobatto nodes. The integral involved in the definition of the performance index is discretized based on the Gauss-Lobatto quadrature rule. The optimal control problem is thereby converted into a mathematical programming program. Thus existing, well-developed optimization algorithms may be used to solve the transformed problem. The method is easy to implement, capable of handling various types of constraints, and yields very accurate results. Illustrative examples are included to demonstrate the capability of the proposed method, and a comparison is made with existing methods in the literature. >

Use of Amazonian Forest Fragments by Understory Insectivorous Birds

Abstract: We sampled understory insectivorous birds in Amazonian forest fragments from before isolation through 9 yr after isolation. We accumulated 3658 mist net captures of 84 insectivorous species in five 1-ha fragments and four 10-ha fragments. Abundance and species richness declined dramatically after isolation, even though fragments were separated from continuous forest by only 70-650 m. Three species of obligate army ant followers disappeared within the first 2 yr after isolation. Mixed-species flocks containing 13 commonly netted species disintegrated within 2-3 yr after isolation, although three species that dropped out of flocks persisted in fragments. Among insectivores not associated with flocks or army ants, only two species of edge specialists were unaffected by frag- mentation. Overall, loss of forest insectivores was not compensated for by an increase in nonforest or previously uncommon species. Secondary vegetation surrounding fragments strongly affected use of fragments after isolation. Fragments surrounded by Vismia, the dominant regrowth where felled forest was burned and temporarily used as cattle pasture, remained depauperate. In contrast, many species returned to fragments by moving through regenerating forest dominated by Cec- ropia, which occurred in areas where the felled forest was not burned. Both 1- and 10-ha fragments surrounded by Cecropia were used by ant followers by 5 yr after isolation. Mixed-species flocks reassembled in 10-ha fragments surrounded by Cecropia by 7-9 yr after isolation, and augmented their group territories by foraging in secondary forest outside fragments. Solitary species were more variable in their responses, although several species returned to 10-ha fragments surrounded by Cecropia. Terrestrial insectivores, such as Scle- rurus leafscrapers and various antbirds, did not return to any fragments, and appear to be the group most vulnerable to fragmentation. Ordination of the insectivore community showed that 1-ha fragments diverged from their pre-isolation communities more than did 10-ha fragments. Communities in 10-ha fragments surrounded by Cecropia were more closely associated with pre-isolation com- munities than those in fragments surrounded by Vismia. Over time, communities in 10-ha fragments surrounded by Cecropia became more like pre-isolation communities, although communities in other fragments generally continued to diverge.

Genocop III: a co-evolutionary algorithm for numerical optimization problems with nonlinear constraints

Abstract: During the last two years several methods have been proposed for handling nonlinear constraints by genetic algorithms for numerical optimization problems; most of them were based on penalty functions. However, the performance of these methods is highly problem-dependent; moreover, many methods require additional tuning of several parameters. We present a new optimization system (Genocop III), which is based on concepts of co-evolution and repair algorithms. We present the results of the system on a few selected test problems and discuss some directions for further research.

In vivo resuscitation, and virulence towards mice, of viable but nonculturable cells of Vibrio vulnificus.

Abstract: Vibrio vulnificus is an estuarine bacterium responsible for 95% of all seafood-related deaths in the United States. The bacterium occurs naturally in molluscan shellfish, and ingestion of raw oysters is typically the source of human infection. V. vulnificus is also known to enter a viable but nonculturable (VBNC) state, wherein the cells are no longer culturable on routine plating media but can be shown to remain viable. Whether or not this human pathogen remains virulent when entering the VBNC state has not been definitively demonstrated. In this study, the VBNC state was induced through a temperature downshift to 5 degrees C, with cells becoming nonculturable ( 10(5) cells in the VBNC state were present in the inoculum. Culturable cells of V. vulnificus, with identification confirmed through PCR, were recovered from the blood and peritoneal cavities of mice which had died from injections of cells present in the VBNC state for at least 3 days. Thus, our data suggest that cells of V. vulnificus remain virulent, at least for some time, when present in the VBNC state and are capable of causing fatal infections following in vivo resuscitation. Our studies also indicate, however, that virulence decreases significantly as cells enter the VBNC state, which may account, at least to some extent, for the decrease in infections caused by this bacterium during winter months.

Entry into, and resuscitation from, the viable but nonculturable state by Vibrio vulnificus in an estuarine environment.

Abstract: Using plate counts, total cell counts, and direct viable counts, we examined the fate of cells of Vibrio vulnificus placed into natural estuarine waters during both winter and summer months. Cells inoculated into membrane diffusion chambers and placed into estuarine waters entered into a viable but nonculturable (VBNC) state in January and February, when the water temperatures were low (average, < 15 degrees C). In contrast, when cells in the VBNC state were placed into the same waters in the warmer months of August through November (average water temperature of ca. 21 degrees C), the cells appeared to undergo a rapid (typically, within 24 h) resuscitation to the fully culturable state. These results were independent of whether the cells were in the logarithmic or stationary phase and whether they were encapsulated or not. This study indicates that the inability to isolate V. vulnificus from cold estuarine sites may be accounted for by entrance of the cells into a VBNC state and that recovery from this state in natural environments may result from a temperature upshift.

Setting the Agenda for a New Europe: The ERT and EC 1992

Abstract: Scholars have disagreed over the origins of the single market programme and, in particular, over the role played by business groups in influencing the 1992 project. This article provides a systematic examination of the major policy actors behind the 1992 project, notably the European Round Table of Industrialists (ERT). It is argued that, contrary to intergovernmentalist interpretations, the ERT was largely responsible for setting the agenda for the single market programme. The article concludes that traditional theories of European integration cannot capture the political role of non-state actors in EU regulatory policymaking, and suggests an alternative approach is necessary.

Psychometric Analysis and Revision of the Opinions Relative to Mainstreaming Scale

Abstract: This article provides supporting evidence for the use of a revised version of the Opinions Relative to Mainstreaming (ORM) scale. Analyses of data produced by a test of the revised scale, the Opinions Relative to Integration of Students with Disabilities (ORI), indicated satisfactory item characteristics and adequate reliability and homogeneity. Initial support for ORI's construct validity was demonstrated by the results of regression analyses relating ORI scores to respondent sociodemographic and experiential data and scores on the Scale of Attitudes Toward Disabled Persons (SADP). The ORI should prove useful to researchers evaluating the attitudes of educators toward the integration of students with disabilities into general education classrooms.

The viable but non-culturable state in the human pathogen Vibrio vulnificus

Abstract: Vibrio vulnificus is a serious human pathogen, accounting for 95% of all seafood-related deaths in the United States. During the winter months, when coastal water temperatures drop below 10 °C, investigators have repeatedly reported their inability to isolate this estuarine bacterium from the environment. We now realize that this apparent ‘die-off’ is actually due to entry of the cells into a ‘viable but non-culturable’ state, a survival response to the low temperature stress. Cells in this state appear dormant, and cannot be cultured in or on routine bacteriological media, but are capable of returning to the actively metabolizing state when the environmental stress is removed. This review describes this non-culturable state in V. vulnificus, and its role in the ecology, physiology, and epidemiology of this pathogen.

Millimeter-wave wireless interconnection of electronic components

Abstract: A millimeter-wave wireless data transmission link is utilized to interconnect multiple electronic components within an enclosed electronic system. More specifically, an electronic apparatus includes a housing, a plurality of separated electronic components located within the housing, and a plurality of millimeter-wave transmit/receive integrated circuit devices, each coupled to a corresponding one of the separated electronic components. Data is transmitted between the plurality of separated electronic components via the millimeter-wave transmit/receive integrated circuit components, each of which includes one or more transmit/receive circuits preferably operating at frequencies above 35 GHz. The transmit and receiving frequencies of the transmit/receive integrated circuit devices can be dynamically set in memory to enable transmission links to be easily reconfigured.

Multi-scale analysis of engineering surfaces

Abstract: Conventional surface characterization techniques involving random process analysis are limited in characterizing multi-scale surface features relevant to manufacturing processes and functions. This paper introduces a novel technique for multi-scale characterization of engineering surfaces by applying wavelet transform. The main advantages of wavelet transform over other existing signal processing techniques are its space-frequency localization and multi-scale view of the components of a signal. Utilizing these properties of wavelet transform, we can effectively apply multi-channel filter banks to the surface data and link the manufacturing and functional aspects of a surface with its multi-scale features. Surfaces produced by typical manufacturing processes are analyzed using wavelet transform, and the usefulness of wavelet transform in the multi-scale analysis of engineering surfaces is demonstrated.

Expert Support Systems for New Product Development Decision Making: A Modeling Framework and Applications

Abstract: A modeling framework that merges knowledge-based expert systems and decision support systems with management science methods for project evaluation is presented. In particular, the strategic decision to commit to full-scale development of a new product is considered. At the core of the framework are the methods and techniques used for acquiring, modeling and processing the expert knowledge and data. Methods and techniques used include scoring models, logic tables, the analytic hierarchy process, discriminant analysis, and rule-based systems. The suggested modeling approach obtains the benefits of normative modeling as well as the flexibility and developmental advantages of expert systems. Additional benefits include reduced information processing and gathering time, which can help to accelerate the product development cycle. Potential spin-offs of this research include applications for project evaluation throughout the product development cycle and other areas such as capital budgeting. Finally, a series of related case studies that have successfully implemented this framework is described.

The Political Economy of Religious Commodities in Cairo

Abstract: Anthropology’s rediscovery of material culture has emphasized the centrality of objects and their production in constituting human experience. In Egypt, the design, mass production and marketing of different classes of religious objects-from prayer beads and bumper stickers to children’s board games and jigsaw puzzles-not only construct boundaries between social groups but create alternative ways of understanding and participating in the Islamic tradition. This article explores the distribution and consumption of Islamic paraphernalia, examining how the development of a mass market in religious consumer goods, brought on in part by Egypt’s shifting place in the global market, has transformed the urban religious consciousness.

Origins of the Ductile Regime in Single-Point Diamond Turning of Semiconductors

Abstract: A germanium surface and the chips produced from a single-point diamond turning process operated in the “ductile regime” have been analyzed by transmission electron microscopy and parallel electron-energy-loss spectroscopy. Lack of fracture damage on the finished surface and continuous chip formation are indicative of a ductile removal process. Periodic thickness variations perpendicular to the machining direction also are observed on these chips and are identified as ductile shear lamellae. The chips consist of an amorphous, elemental germanium matrix containing varying amounts of microcrystalline germanium fragments. The relative orientation of machining marks and crystallographic fragment texture are used to position individual chips with respect to the initial angular cutting zone on the wafer. Chips with high fragment content correlate directly to cutting zones subject to the highest resolved tensile stress on cleavage planes. These findings are explained in the context of a high-pressure metallization (brittle-to-ductile) transformation with ductility limited by the onset of classical brittle fracture.

Race and decision making within juvenile justice: The importance of context

Abstract: Previous tests of the influence of race on decision making within juvenile justice proceedings have traditionally focused on case-level variables and/or macrolevel factors that characterize the jurisdictions under study. Often excluded are measures of the attitudinal context within which decision making occurs. Using a revised conflict perspective that incorporates the role of racial stereotyping, hypotheses are developed centering on racial differences in case processing decisions within four midwest jurisdictions. Attitudes of juvenile court officials toward the punitiveness of the juvenile court and perceptions regarding differences between the behavior and attitudes of whites and those of African Americans are included in additive and race interactive models of five decision-making stages. Results indicate both lenient and harsh treatment of African Americans compared to whites. Hypotheses regarding racial stereotyping in the decision-making process receive some support and the discussion focuses on how inconsistent racial effects may be a function of variation in structural “coupling” across system decision points.

Transient power supply current testing of digital CMOS circuits

Abstract: This paper presents, in a tutorial fashion, a test technique that employs the transient power supply current, i/sub DDT/, as a window of observability into the switching behaviour of an integrated circuit. The premise is that when a circuit switches states, a temporary path is established between power and ground which results in a transient current. With proper power tree distribution, observing this transient current provides direct insight into the switching pattern of a circuit under a given stimulus. This paper includes an overall summary of physical experiments that have been conducted (previously reported in parts) as well as new results on the test overhead. The physical experimental results show i/sub DDT/ to be effective in detecting disturb faults in SRAMs and drain/ source opens in general CMOS logic structures.

Functions of a breast cancer support group as perceived by the participants: an ethnographic study.

Abstract: The purpose of this study was to obtain an understanding of the functions of a breast cancer support group as perceived by the participants. An ethnographic method of research was used. Data were collected by participant observation and tape-recorded interviews during the weekly support group meetings. The convenience sample included one professional group leader and 15 women diagnosed with breast cancer within a range of 2 weeks to 7 years. Two key informants were chosen to clarify and validate data. Content analysis was performed on the data obtained from the tape recordings of 10 group meetings and from the two key informant interviews. Three categories of functions of the breast cancer support group emerged from the data analysis, including exchanging information, sharing the illness experience, and providing strength. As the incidence rate of breast cancer continues to increase, it is imperative that nurses recognize the physical and psychological reactions to breast cancer and identify sources of social support for women. Nurses should be cognizant of the functions of a breast cancer support group in order to share this information with women and encourage them to actively participate with others sharing the same experience.

Induction of cold-responsive proteins in Vibrio vulnificus.

Abstract: We have studied the response of Vibrio vulnificus to temperature shifts (23 to 13 degrees C) within the organism9s permissive growth range. Cold shift induced a diminution in protein synthesis. Following a short lag, cells began growth at a new rate. Forty proteins were induced by this downshift.

Transient power supply current monitoring—a new test method for CMOS VLSI circuits

Abstract: We present a new method for testing digital CMOS integrated circuits. The new method is based on the following premise: monitor the switching behavior of a circuit as opposed to the output logic state. We use the transient power supply current as a window of observability into the circuit switching behavior. A method for isolating normal switching transients from those which result from defects is introduced. The feasibility of this new testing approach is investigated by conducting several experiments involving the design of integrated circuits with built-in defects, fabrication, and physical testing. The results of these experiments show this new test method to be a promising one for detecting defects that can escape stuck-at testing andI DDQ testing.

The Hexis of Interpretation: Islam and the Body in the Egyptian Popular School

Abstract: This article examines how travelers, colonial officials, and educators have treated prayer and other body rituals in Egyptian popular schools. Once the object of colonial critiques of indigenous pedagogy, body ritual has now become the focus of a functionalist discourse that reads bodily postures and movements as natural manifestations of social, ideological, and cosmological structures. Starting from Bourdieu’s notion of hexis, the literal embodiment of ideology, the article examines how Egyptians—and anthropologists—extract meaning from ritual behavior.

Living with chronic mental illness: understanding the role of work.

Abstract: This paper is based upon an exploratory study designed to examine the role of work within the lives of those with severe, persistent mental illness (SPMI). In-depth, open ended interviews were conducted with a small number of consumers (n = 10) who attend a clubhouse for those with SPMI where emphasis is placed upon preparation for work. Given that little is known about how work impinges upon or enriches the lives of consumers we asked consumers about their experience of mental illness and work throughout their life trajectories. This paper describes these work experiences, the effect of mental illness and treatment compliance upon their ability to work, and the relationship of work to stress. We found that in general some kind of meaningful activity was important to these consumers, but many had found work experiences to be stressful and were cautious about their subsequent abilities to sustain meaningful employment. We suggest that subsequent research needs to examine the nature of the work environment, and that work environments may be usefully distinguished in terms of level of expressed emotion.

Perceived patient deviance and avoidance by nurses

Abstract: Perceived patient deviance and its relationship to avoidance behaviors of nurses was examined using a social deviance/labeling framework. Avoidance included a reduction in the number and duration of nursing contacts with patients, a reduction in the number of nurse-initiated contacts, the use of physical restraints, and failure to meet the individualized needs of patients. Fifty-two registered nurses on adult health units classified known patients into three study groups: ideal patient, neutral patient, and difficult (deviant) patient. Analysis of variance showed no significant differences for mean number, duration, and initiator of nurse-patient contacts. Significant differences were found in the Psychosocial Individual, Physical, and General subscales of the Slater Nursing Competencies Rating Scale and in the use of physical restraints for the three study groups. Agreement of nurses in their classification of patients occurred in 74.63% of cases. The results suggest that the label of difficult (deviant) patient is well communicated among nurses and that it has a negative influence on the quality of care.

Stationary parabolic Anderson model and intermittency

Abstract: This paper is devoted to the analysis of the large time behavior of the solutions of the Anderson parabolic problem: $$\frac{{\partial u}}{{\partial t}} = \kappa \Delta u\xi (x)u$$ when the potential ξ(x) is a homogeneous ergodic random field on ℝ d . Our goal is to prove the asymptotic spatial intermittency of the solution and for this reason, we analyze the large time properties of all the moments of the positive solutions. This provides an extension to the continuous space ℝ d of the work done originally by Gartner and Molchanov in the case of the lattice ℤ d . In the process of our moment analysis, we show that it is possible to exhibit new asymptotic regimes by considering a special class of generalized Gaussian fields, interpolating continuously between the exponent 2 which is found in the case of bona fide continuous Gaussian fields ξ(x) and the exponent 3/2 appearing in the case of a one dimensional white noise. Finally, we also determine the precise almost sure large time asymptotics of the positive solutions.