Showing papers by "University of Texas at Arlington published in 1982"

Cognition in Parkinson disease: An event‐related potential perspective

Abstract: Auditory event-related potentials (ERP) elicited in a target detection stimulus paradigm and pattern-shift visual ERPs were studied in 20 male patients with idiopathic Parkinson disease (PD) and 20 age-matched normal controls. Patients showed significantly increased latencies for both the P200 and P300 components of the auditory ERP. Patients and controls showed no significant differences in latency of the visual ERP but patients showed significantly decreased amplitude. Only one of five neuropsychological measures, the Symbol Digit Modalities test (SDMT), showed a significant negative correlation with P300 latency. The significant association between the two measures that showed impairments in the PD patients (P300 latency and SDMT scores) suggested that these measures reflect a common, disrupted aspect of cognitive function in PD.

Optimal Power Flow Based Upon P-Q Decomposition

Abstract: The optimal power flow problem is formulated based upon the decoupling principle well recognized in bulk power transmission loadflow. This principle is exploited by decomposing the OPF formulation into a P-Problem (P-?real power model) and a Q-Problem (Q-V reactive power model); which simplifies the formulation, improves computation time and permits a certain flexibility in the types of calculations desired (i.e., P-Problem, Q-Problem or both).

Optimal Distribution Substation and Primary Feeder Planning VIA the Fixed Charge Network Formulation

Abstract: The planning methodology presented in this paper is an application of recent advances in optimization techniques for distribution substation siting and radial feeder planning. The concept of a long range horizon year (target) is used together with a time-phased expansion process beginning with the base year and progressing to the target year. An optimal static horizon year design is first determined using a fixed charge transshipment problem formulation (FCNP). The FCNP solution methodology employs the branch-and- bound algorithm and includes explicit modeling of fixed charge and variable cost components for improved accu- racy. The time-phased expansion process selects substation sites and feeder routings from the horizon (or target) year plan, thus providing an orderly and coherent expansion. This method easily incorporates existing facilities in the decision process for maximum benefit. An example of an actual planning study is presented to illustrate the horizon year target system selection and the corresponding time-phased expansion patterns.

Cross- vs. within-racial judgments of attractiveness

Abstract: Subjects from two pairs of ethnic groups (Chinese and White in Experiment 1, Black and White in Experiment 2) judged the attractiveness of faces in yearbook pictures of persons that belonged to their own or to the other ethnic group. This was to see whether: (1) a given group would perceive more variation in the attractiveness of faces belonging to its own vs. the other ethnic group, as suggested by the cross-racial literature, for example, Malpass and Kravitz (1969), and (2) the two groups would use the same or different rules to define attractiveness. There were essentially no differences in perceived variation for cross- vs. within-racial judgments, but there were differences in the criteria used to define attractiveness. As expected, Black and White aesthetic criteria were more like one another than were Chinese and White criteria. Discussion centered around reconciling these findings with the recognition literature.

The use of social services by black and white elderly

Abstract: Little is known about the roles of the family, kin, and non-kin support networks in determining the use of social services by the elderly. The purpose of this study was to examine the role of the formal and informal support systems in explaining social service utilization by Black and White elderly. Path analytic procedures are used to test an explanatory model of utilization by a national area probability sample of 3.996 non-institutionalized elderly. The findings indicate that informal family support was more important for Black elderly than White elderly. In addition, family aid was found to be supplementary rather than an alternative support system. In the planning, designing, and delivery of social services to the elderly, it is imperative that racial and cultural differences become explicit input factors. Additionally, future researchers have a responsibility to employ research procedures capable of simultaneously dealing with a comprehensive range of variables in investigating this rather complex p...

Structural Weight Comparison of a Joined Wing and a Conventional Wing

Abstract: A structural weight comparison was made between a new concept wing design, called a "Joined Wing," and a reference conventional wing-plus-horizontal tail (Boeing 727). The joined-wing analysis includes two cases that differ only in minimum gage skin thickness. The comparison was accomplished by constructing finite-element computer models of each wing configuration, analyzing each for optimum skin thickness, then determining the structural weight of each wing. The optimizations were based on a fully stressed design concept using a Von Mises criterion for maximum allowable stress. The joined wing was found to be lighter by 12-22%.

Phosphorus dynamics of the procaryotic nannoplankton in a Michigan lake1

Abstract: The small-celled cyanobacteria that dominate Third Sister Lake, Michigan, during summer have extraordinary uptake capabilities for phosphate. Under enriched conditions, the cells can double their phosphorus content in 2 min or less but can sustain the high rates for only a few minutes. ,With equal initial access to the nutrient, the small procaryotes are ultimately more successful than are coexisting eucaryotes in converting the nutrient into new cell biomass.

On the locus of the stimulus suffix effect

Abstract: Two experiments contrasted short-term memory and sensory memory (precategorical acoustic storage) explanations of the stimulus suffix effect Experiment 1 attempted to interfere with recency recall by forcing subjects to encode nonverbal acoustic suffixes into a verbal, articulatory code Subjects in this condition showed recall that was comparable to that of subjects who were told to ignore the suffixes However, Experiment 2 showed that silently mouthed articulation of a suffix can produce interference on recall of recency items, although not as much as that produced by vocal articulation The results are discussed in terms of current models of the stimulus suffix effect

The Effects of Reduced Voltages on the Efficiency of Electric Loads

Abstract: The paper reports the results from Phase I of Electric Power Research Institute RP1419 and describes the efficiency of important power system loads as a function of voltage. A wide variety of loads have been tested at seven input voltages ranging 100/200 to 126/252 volts, and a methodology has been developed to estimate distribution system efficiency as it relates to the operating level of voltage.

Extension of the method of partial retention of diatomic differential overlap to second row atoms and transition metals

Abstract: The method of partial retention of diatomic differential overlap (PRDDO) has been extended to the elements through the first transition series. A minimum basis set of Slatertype orbitals is employed, with optional 3d functions on atoms in the second major row. The 3d shell for transition metal atoms is a fixed-contracted double-ζ combination of Slater orbitals. The method retains the basic n3 dependency inherent in PRDDO. Limited one-center parameterization and empirical two-center exchange integrals are included. The overall accuracy of the approach is comparable to that of the PRDDO method as previously applied to molecules containing first-row atoms only.

Prenatal exposure to virilizing progestins: an adult follow-up study of twelve women.

Abstract: Psychological data were collected on 12 young women, aged 16 to 27 years, with a history of prenatal progestin exposure. In 11 cases, this exposure had induced virilization of the external genitalia. The 12th woman was an anatomically unaffected sister of one of the other women. The sample was composed of 10 women reported on as children by Ehrhardt and Money (1967), Money and Ehrhardt, (1972) as well as two others who were added to this group because they conformed to the original selection criteria for the Money and Ehrhardt studies. Of the 12 women, 10 had completed high school; of these, 7 were in college, 2 were in graduate school, and 1 was raising a family full-time. None of the 12 had a history of difficulty in establishing friendships or dating relationships. Despite childhood characterizations as “tomboys” and avid interest in high school sports, none of the women pursued sports as a career or major pastime. Because of difficulties in personally contacting all 12 women, data on erotic behavior are available for only 6. Only one of these 6, the youngest, reported no erotic experience, and the remaining 5 reported exclusively heterosexual erotic experience and imagery.

Some Thermophysical Properties of Paraffin Wax as a Thermal Storage Medium

Abstract: An experimental study is conducted to determine the suitability of paraffin wax SUNTECH P116 as a phase change material for storage of thermal energy. Certain temperature-dependent thermophysical properties in the neighborhood of the melting point useful for this study, but not adeguately available in the literature, are measured. They

Sedimentation and Accumulation of organic carbon in the Angola Basin and on Walvis Ridge: Preliminary results of Deep Sea Drilling Project Leg 75

Abstract: Leg 75 investigated two periods of accumulation of sediments rich in organic matter. In the Upper Cretaceous section, more than 200 beds of gray or black shale and mudstone rich in organic carbon (as much as 18%) are intercalated within a sequence of red and green mudstones that contain less than 1% organic carbon. The black shale beds are 1 to 62 cm thick and constitute less than 10% of the section in the 20 cores in which they were recovered. Both turbiditic and pelagic processes were involved in the deposition of these black shale beds. A combination of factors, including increased productivity and warm saline bottom waters, probably resulted in a delicate balance between oxic and anoxic conditions that periodically favored the accumulation and preservation of organic matter in the basinal sediments. The Pliocene-Pleistocene sediments are thoroughly bioturbated, and there is no evidence of persisting anoxia in the overlying water in spite of the high organic carbon content of the sediments. These two different periods of accumulation of organic matter both resulted in significant concentration of organic carbon (>2%, maximum 18%), but the Pliocene-Pleistocene sediments contain the greater mass of organic carbon per unit volume of the solid sediment.

Stressors and Remediation Techniques for Special Educators.

Abstract: Special educator stressors within the realm of administrative remediation are identified and organized under the topics of roles, resources, and relationships. Problems such as lack of role clarity...

A High-Speed FDCT Processor for Real-Time Processing of NTSC Color TV Signal

Abstract: A FDCT (fast discrete cosine transform) processor is designed to have throughput rates consistent with high speed, (real time) processing of standard National Television Systems Committee (NTSC) color television signal sampled at 3fsc = 10.7 MHz where fsc is the color subcarrier frequency. This is achieved by using a highly modular structure in a pipeline configuration. The development phase includes the selection of a suitable algorithm and the utilization of important features of the algorithm for hardware implementation. Since the prototype is used for research purposes, provisions are made for versatility of the control and selectabilifty of , the processing accuracy. The FDCT processor is capable of processing 4- or 8- or 16- point input segments and can also be used as a part of a larger system which processes a 32-point input segment. With minor modifications, the algorithm and the basic hardware design can be used for the fast inverse DCT (FIDCT) processor.