Nebraska Academy of Sciences Annual Meeting
Nebraska Wesleyan Campus, Lincoln
2000 Abstracts

MEASURING AIRLINE OPERATIONAL EFFICIENCY IN THE U.S. MAJOR AIRLINE INDUSTRY, THE 1999 RESULTS

Brent D. Bowen, Aviation Institute, University of Nebraska at Omaha, Omaha, Nebraska, 68182-0508

This Airline Quality Rating model is developed using public data for the United States (U.S.) major airline industry available from the U.S. Department of Transportation, Federal Aviation Administration, the National Transportation Safety Board, and other public and private sector sources. Data points include operational performance indicators, flight problems, and other critical factors. Data from these sources provide opportunity to develop a model based on a complex dot product equation of two vectors. A row vector is weighted for importance by a key informant panel of government, industry, and consumer experts, while a column vector is established with the factor value. The resulting equation is the dot product of two vectors, C the row vector, and V the column vector. The equation, known as the national Airline Quality Rating (AQR), where Q is quality, C is weight, and V is the value of the variables. The combined results of monthly data for the 1999 calendar year are reviewed.

 INSIGHTS INTO AUTOMATION MONITORING ERRORS USING LOW-FIDELITY SIMULATION

R. Jason Weiss and J.P. Craiger, Center for Management and Information Technology, University of Nebraska at Omaha, Omaha, Nebraska 68182.

Recent research on human monitoring of automated systems focuses on two types of operator errors. Omission errors occur when the operator fails to detect a system event presumed to be under automated control. Commission errors result from the operator following an inappropriate automated directive. The present study investigated the roles of workload, visual warning indicators, and the operator’s need for cognition in monitoring among 54 undergraduate psychology students. Multiple regression analysis revealed interactive effects for taskload and visual indicators on omission errors, in addition to a first-order effect for need for cognition. The combination of a heavy workload and visual indicators led to a greater tendency to commit omission errors, although this effect was reduced by need for cognition. For commission errors, first-order and interaction effects were found for flashing indicators and need for cognition. In combination, visual indicators and high need for cognition led to increased commission errors.

MORPHINE EFFECTS ON CIRCADIAN NOCICEPTION AND BETA-ENDORPHIN

Natalie A. Rasmussen and L.A. Farr, College of Nursing, University of Nebraska Medical Center, Omaha, Nebraska 68198-5330.

 

Little is known about the effects of morphine on beta-endorphin (BE). Since morphine is a widely used analgesic, its effects need to be studied. This study was designed to examine the effects of morphine on BE at different times of day. The first two studies described the secretion of BE following acute pain. 244 Dilute Brown Non-Agouti (DBA) mice were exposed to a 55 E C or room temperature hot-plate and trunk blood was collected. BE was analyzed using radioimmunoassay. Data were analyzed with ANOVA. Both groups increased their BE secretion immediately. The response of mice exposed to the 55 E C hot-plate lasted 20 minutes longer than the controls. A marked circadian rhythm in BE secretion was observed. In the third study, 46 treatment mice were injected with 2.3 mg/kg of morphine and 45 control mice were injected with saline and exposed to a hot-plate set at 55 E C every four hours (six time points, 6-8 treatments and 7-8 controls/time point) for 24 hours. Control mice showed a robust circadian BE rhythm with a secretion peak at 0000 and a nadir at 1200. Morphine-injected mice showed no circadian BE rhythm. This study was supported in part by NASA Grant # NGT 40051 and Sigma Theta Tau International Grant (1997).

SOFTWARE BLACK BOX: AN ALTERNATIVE METHOD FOR SOFTWARE FAILURE INVESTIGATION

Sebastian Elbaum, Department of Computer Science and Engineering, University of Nebraska, Lincoln, Nebraska 68588.

It is extremely difficult to understand why complex software systems fail. As more intricate software systems are developed, determining the nature and causes of a software failure becomes even a greater challenge. However, learning from software failures is an essential step towards the development of more reliable software systems. We are currently researching alternative methods to understand and analyze software failures. Our efforts are concentrated on the Software Black Box (SBB), which constitutes a framework that facilitates the investigation and understanding of software failures. The SBB specifies a mechanism to capture the essentials of an executing program, and it provides a reconstruction technique that allows the generation of the scenarios that may have led to the software failure. We are now in the process of defining a set of SBB extensions to handle a distributed multiprocessor environment and implementing the corresponding experimental prototype.

EFFECTS OF GRAVITY AND AMBIENT PRESSURE ON LIQUID FUEL DROPLET EVAPORATION

George Gogos and S. Soh, Department of Mechanical Engineering, University of Nebraska, Lincoln, Nebraska 68588-0656.

A numerical study of single droplet evaporation over a wide range of ambient pressures both under zero and under normal gravity conditions has been conducted. Comparisons with the experiments of Matlosz et al. (Int. J. Heat Mass Transfer, vol 15, pp.831-852, 1972) for n-hexane (normal gravity) and Nomura et al.(4th Asian-Pacific International Symposium on Combustion and Energy Utilization, pp. 266-271, 1997) for n-heptane (zero and normal gravity) are discussed. Numerically predicted results are in good agreement with experimental data especially at low and moderate ambient pressures. It is found that the enhancement in the rate of droplet evaporation becomes more dominant with increasing ambient pressure and droplet diameter due to the increase in the Grashof number. Results presented should be particularly of interest to researchers conducting experiments on droplet evaporation at elevated pressures within a normal gravity environment.

APPLICATION OF SEAWIFS IMAGERY DATA TO CHARACTERIZE VEGETATION STATE AND WATER DISTRIBUTION IN THE PLATTE RIVER BASIN

Joel Connot and J. Schalles, Center for Advanced Land Management Information Technologies, University of Nebraska-Lincoln, Lincoln, NE 68588

We are examining attributes of the entire Platte River Basin using the SeaWIFs sensor on the Orbview-2 satellite. The satellite was launched in 1997 and has 6 visible and 2 near-infrared bands with good spectral and radiometric resolution. Spatial resolution is about 1.2 km. The satellite has a polar orbit with daily coverage of most regions of the world. CALMIT at the University of Nebraska is a receiving station for North American. Data is received daily and archived on CD-ROM. This sensor system has advanced characterics compared to NOAA's widely utilized AVHRR sensor. Parallel data sets from these two sensors will be compared. We are developing bi-weekly composited images of vegetation state for the 1999 growing season. The spectral bands of SeaWIFs permit the calculation of both a conventional greeness index (red NDVI) and a new index (green NDVI) developed by Anatoly Gitelson and coworkers. This later index has a better ability to detect relatively small changes in vegetation state and may be particularly useful for conditions of high biomass and detection of early vegetation stress. The images clearly show vegetation conditions and relationship to climatic gradients and irrigation patterns within the basin. We are developing phenology trends in these indexes for representative areas of agricultural and non-agricultural lands within the basin. We will also present results related to the drought patterns that began in the fall of 1999.

THE SMART AIR TRANSPORT SYSTEM

Frederick D. Hansen, B.D. Bowen, Aviation Institute, University of Nebraska at Omaha, Omaha, Nebraska 68182-0508; and B.J. Holmes, NASA Langley Research Center, Hampton, Virginia 23681.

The Smart Air Transport System (SATS) concept is a safe travel alternative that will free people and products from transportation delays, thereby creating access to more communities in less time. This initiative is motivated by the soaring demand for intercity travel during an era of increasing saturation of the interstate and hub-and-spoke systems. A comprehensive upgrade of public infrastructure must be planned, coordinated, and implemented to complement the existing framework of the national air transportation system. Nebraska is providing research in key public infrastructure areas including systemic change and innovation, public finance and economics, state and local airport planning for SATS implementation, and social outreach and education. An important element of the early research was the development of a Nebraska SATS airport infrastructure matrix. This matrix and other research outcomes are reported.

X-RAY SPECTROMETRY AND THE NASA NEAR MISSION

Sam Cipolla, Department of Physics, Creighton University, Omaha, Nebraska 68178-0114.

The Near Earth Asteroid Rendezvous (NEAR) spacecraft was launched in 1996 and is scheduled to start a year-long orbiting of the asteroid 433 Eros on 2-14-00. One purpose of the mission is to determine surface elemental composition of Eros through x-ray spectrometry. Characteristic x-rays are excited by bombardment of the surface by x-rays and protons from the sun. Some aspects of the proton-excited x-ray analysis will be described.

EVAPORATION OF A SPHERICAL MOVING FUEL DROPLET OVER A WIDE RANGE OF AMBIENT PRESSURES WITHIN A NITROGEN ENVIRONMENT

George Gogos and H. Zhang, Department of Mechanical Engineering, University of Nebraska – Lincoln, Lincoln, Nebraska 68588-0656.

A comprehensive numerical model has been developed to study droplet evaporation in a forced convective, high pressure and high temperature nitrogen environment. Predictions for a stagnant droplet are in very good agreement with the experimental data of Nomura et al. (Twenty-Sixth Symposium (International) on Combustion, pp. 1267-1273, 1996), especially for low and moderate ambient pressures. Predictions for a moving evaporating droplet are in very good agreement with the experimental data of Gokalp et al. (Twenty-Second Symposium (International) on Combustion, pp. 2027-2035, 1988). Results are presented employing the droplet evaporation constant as defined by Ristau et al. (Microgravity Sci. Technol. VI/4, pp. 223-228, 1993). It is predicted that the droplet evaporation constant increases almost linearly with ambient pressure. At an ambient pressure which is a few times the thermodynamic critical pressure of the fuel the slope of the evaporation constant changes sharply, leading into a weak linear variation with further increase in the ambient pressure. With increasing initial droplet velocity, the above change in slope occurs at higher ambient pressures.

 BARRIERS TO DIFFUSION OF TECHNOLOGY AND TECHNOLOGY TRANSFER TO LOCAL AIRPORTS

B.J. Reed, Department of Public Administration, University of Nebraska at Omaha, Omaha, Nebraska 68182-0276.

Research on the implementation of the Small Aircraft Transportation System requires consideration of the barriers that exist in diffusion of technology throughout that nation’s general aviation airports. Barriers exist in many areas. First, the conservative nature of organizations and their unwillingness to accept different approaches to delivering services. Public organizations, by their nature are risk adverse. A second barrier to diffusion of technology is the financial resources necessary to modify and apply the technology appropriate to the general aviation facility. Those developing the technology and those who apply the technology often have very different orientations and values. They also have different missions, objectives and structures. Also, the ability to communicate and understand the application of SATS technology and the value of that technology is often lacking. Finally, there may be statutory and administrative barriers to successful implementation.

INFORMATION THEORETIC ASSESSMENT OF HYPERSPECTRAL IMAGING SYSTEMS

Luyin Cao and S.E. Reichenbach, Computer Science and Engineering Department, University of Nebraska – Lincoln, Lincoln, Nebraska, 68588.

This work develops a method for assessing information density and efficiency of hyperspectral imaging systems. The information density of the acquired signal is computed as a function of the hyperspectral system design, signal-to-noise ratio, and statistics of the scene radiance. Information efficiency is the ratio of the information density to the data density. The assessment can be used in system design, for example, to optimize information efficiency with respect to the number of spectral bands. That is, information efficiency as a function of the number of spectral bands exhibits a distinct signal maximum. This talk considers non-uniform bandwidths in hyperspectral imaging of scenes that are non-homogeneous with respect to spectral wavelength. Beginning with the lowest frequency, the interval between bands is set to yield the maximum information efficiency. Two experiments illustrate the approach, one using a simple model for the scene radiance autocorrelation function, and the other is using the deterministic autocorrelation function of a hyperspectral image from the ASAS. The design with non-uniform bandwidths yields greater information efficiency than an optimal design with uniform bandwidths.

A MODULAR ROBOTIC INFRASTRUCTURE FOR PLANETARY EXPLORATION

Shane Farritor, Department of Mechanical Engineering, University of Nebraska – Lincoln, Lincoln, Nebraska 68588-0656

This project studies a Planetary Surface Modular Robotic System (PSMRS). Human exploration of the Moon and Mars is planned for the 2010-2020 timeframe. Extensive use of robotics will reduce costs and increase safety. A wide variety of tasks, requiring a large variation in robot capabilities, will be performed. For example, large quantities of regolith may need to be manipulated, requiring bulldozer-like capabilities. Also, delicate scientific instruments may need to be deployed. Creating individual robots for each task is not an efficient approach, especially since not all tasks can be foreseen. The PSMRS is proposed to address these unique challenges. Here a robotic infrastructure, rather than an individual robot(s), is proposed. The system is based on a fundamentally modular design to efficiently address the unique challenges of planetary surface operations. The system consists of modules that can be assembled into dramatically different robots to perform dramatically different tasks. This approach promotes efficiency and reliability through adaptability.

SYSTEMS ENGINEERING APPROACH TO SATS IMPLEMENTATION IN NEBRASKA

Massoum Moussavi, Department of Civil Engineering, University of Nebraska – Lincoln, Lincoln, Nebraska 68182-0178.

This paper discusses the systems engineering approach to Smart Air Transport System (SATS) implementation in the state of Nebraska. SATS is defined as an intermodal, rapid transit, air travel system. To plan and coordinate the implementation of SATS, policy makers must bring together a variety of mental models, translate them into a common language, and determine simultaneously all their important implications. While it is possible for the experts to understand portions of the SATS implementation projects, synthesizing these so as to account for all the interactions without a formal technique is impossible. Using systems engineering approach, SATS metrics are identified and used to develop a computer-based SATS implementation model. Three alternative forms of the model are developed. The verbal description is a mental model expressed in words, and the visual description is diagrammatic and shows the cause-and-effect relationships between system metrics. The visual model is then translated into mathematical/computer model. All forms of the model are equivalent, with any one form merely serving as an aid to understanding for someone who is not fluent in the other languages. However, the verbal description does not lend itself to formal analysis. The visual causal diagram can only be analyzed qualitatively. The mathematical/computer model is by far the most precise and is the only representation of the system that permits quantitative analysis and the evaluation of alternative plans and strategies.

THERMODYNAMICS OF DNA HAIRPINS: INCLUSION OF LESIONS AND INTERACTIONS INTERCALATORS

Shelly Sutherland and L.A. Marky, Department of Pharmaceutical Sciences, University of Nebraska Medical Center, Omaha, Nebraska 68198-6025

Bulges and mismatches are formed during replication of DNA because of frameshift mutations or by simply errors of the DNA polymerase. We hope to learn: What are the physical effects of placing a bulge or a mismatch in a DNA molecule? And, would these lesions increase the affinity towards drugs? In this project, we plan to investigate the relative thermodynamic contribution of bulges and mismatches to the overall stability of DNA and the overall energetics of its interaction with intercalators. We will study the unfolding of DNA single-stranded loops (hairpin loops) because their helix-coil transition resembles the in vivo opening of DNA. These hairpins will have the sequence d(GCXGCT5GCGC), where X is A, T, G, or C and d(GCXGCT5GCYGC), where X and Y are any combination of mismatches (T-T, G-A, etc). We will use a combination of temperature-dependent UV spectroscopy and differential scanning calorimetric techniques to obtain complete thermodynamic profiles (?G, ?H, ?S and the release of counterions) for the unfolding of each hairpin molecule. We will also study the interaction of well-known intercalators, ethidium bromide and propidium iodide, with these hairpins. To this effect, we will use isothermal titration calorimetry to obtain complete binding profiles (binding affinity, heat and complex stoichiometry).

SPACE ACTIVITIES IN NEBRASKA K-12 CLASSROOMS: AN ACTION RESEARCH AND CURRICULUM MODEL

Neal Grandgenett, R. Pawloski, N. Topp, E. Ostler, R. Mortenson and C. Mitchell, Department of Teacher Education, University of Nebraska at Omaha, Omaha, Nebraska 68182.

This presentation will report on the approach, results, and implications of several action research projects being conducted by the University of Nebraska at Omaha Office of Internet Studies. The projects include three different NASA funded projects with both teachers and students, which involve focused teacher curriculum development and action research within their own classrooms. All of the projects relate to the interpretation of space imagery, and the use of space data in the learning of mathematics and science concepts, targeting national science standards. To date, over 120 teachers, and more than 1000 students have participated in these space-related activities. Implications are also drawn from the action research results that support the effectiveness and utility for such project sponsored activities when the process carefully defines the curriculum development and research roles for the classroom teacher.

A WEB-BASED LATEST PLANTING DATE CALCULATOR

Gautam Jindal and S.E. Reichenbach, Department of Computer Science and Engineering, University of Nebraska, Lincoln, Nebraska 68588.

To determine how late a particular corn hybrid (or other crop variety) can be planted in a specific environment is an important decision to minimize the risk of frost in the spring and before the crop matures. The best hybrid maturity for a plantation will usually be the one that not only ensures utilization of the entire growing season, but which also minimizes the risk of the crop being killed by frost before maturity. This decision-support tool estimates the probabilities of growing degree days (GDDs) and freeze risk for any specified field in Nebraska so that a farmer can determine the hybrid that best suits the heat characteristics of his field. The GDD maps can be computed using five parameters (Northing, Easting, Altitude, Aspect, Slope) provided by the Digital Elevation Map (DEM). After finding the GDD map, a hybrid can be selected for the field.

FINANCING THE AIRPORT OF THE FUTURE: THE SMALL AIRCRAFT TRANSPORTATION SYSTEM

John R. Bartle, Department of Public Administration, University of Nebraska at Omaha, Omaha, Nebraska 68182-0276.

SATS, the Smart Air Transport System, is a NASA initiative whose goal is to "enable doorstep-to-destination travel at four times the speed of highways." As SATS is a federal program and many airports in the U.S. are under local government control, many rural and suburban airports will have to modify their infrastructure and increase their investment to accomplish this initiative. This paper discusses how this investment might be financed. The main alternatives are: federal grants, local debt, user charges, and innovative loans or private sources. All present trade-offs, but this paper concludes that the most appropriate approach is some mixture of debt, financed in part by user fees and future economic development along with limited federal aid. For SATS to be financially and administratively sustainable, it needs a financing mechanism that links costs and benefits. This will be a change in both federal and local airport finance policy.

INCORPORATING REMOTE SENSING DATA INTO MODELS FOR ESTIMATING CROP YIELD

Ryan N. Axmann and D.C. Rundquist, Center for Advanced Land Management Information Technologies, University of Nebraska – Lincoln, Lincoln, Nebraska 68588-0517

The paper describes research aimed at developing technologies and methodologies for using remotely sensed data as an input to models designed for estimating final crop yield in corn and soybeans. The research took place at the University of Nebraska Agricultural Research and Development Center (ARDC), located near Mead, NE. Field-acquired sensor data (of high spectral resolution) were analyzed along with airborne-sensor data (of low spectral resolution) in order to assess their utility for yield prediction. Meteorological data and other ancillary information were examined in conjunction with the remotely sensed data. Findings are encouraging, although some limitations exist. Results contribute to both basic and applied science.

NUMERICAL SIMULATION OF N-HEPTANE DROPLET EXTINCTION DUE TO FORCED CONVECTION

George Gogos and D.N. Pope, Department of Mechanical Engineering, University of Nebraska – Lincoln, Lincoln, Nebraska 68588-0656.

The extinction of an envelope flame at the forward stagnation point of a liquid fuel droplet due to forced convection is numerically investigated. The droplet is oxidizing within an air stream at atmospheric pressure and under zero-gravity conditions. Results for extinction velocity as a function of droplet diameter and freestream temperature are presented for a n-heptane droplet. A wide range of droplet diameters and freestream temperatures are considered with the corresponding results being of interest to experimentalists working with droplets under micro-gravity conditions. Experimental results available in the literature for various fuels, and different droplet diameters and ambient temperatures, compare well with the numerical predictions for n–heptane. It is predicted that the extinction velocity as a function of droplet diameter exhibits a nonlinear dependence for small diameters (approx. < 1 mm), and a linear dependence for large diameters (approx. > 2 mm).

DIGITAL IMAGE PROCESSING FOR THREE-DIMENSIONAL GAS CHOMATOGRAPHY

Quanyu Zhu and S.E. Reichenbach, Department of Computer Science and Engineering, University of Nebraska, Lincoln, Nebraska 68588-0115.

In the art of gas chromatography (GC), the process of thermal modulation makes possible comprehensive multi-dimensional separation techniques that have revealed startling complexity in many chemical mixtures. Two-dimensional comprehensive GCxGC is a major advance in the field of chemical separation. Zoex Corporation and researchers at UNL, have developed techniques for pre-processing GCxGC images and for detecting and locating chemical peaks in the images. Recently, the approach has yielded three-dimensional separations. In order to analyze the 3D GC images, the two-dimensional approaches must be extended. This talk will survey the literature on 3D images and suggest approaches for processing and analyzing the 3D GC images.

DATA POINTS FOR THE ANALYSIS OF AIRLINE SAFETY INFORMATION

Brent D. Bowen and C.T. Lu, Aviation Institute, University of Nebraska at Omaha, Omaha, Nebraska 68182-0508

Concern for the safety of flight is at the forefront of attention with airlines, government, and the public. In the aftermath of recent airline tragedies, such as TWA Flight 800 and ValuJet Flight 592, several consumer advocacy groups, investigative commissions, media and the public have called for an aviation safety ranking system, as it is purported that a publically available safety ranking would enhance airline safety. Unfortunately, a comprehensive measuring tool of airline safety does not exist to date. In order to examine the feasibility of the safety measure, a complex equation through the application of Analytic Hierarchy Process (AHP) will be utilized to develop a weighted average measure of safety indicators (i.e. the number of enforcement actions by the FAA, the rate of accidents and incidents, maintenance or flight deficiency, amount of fatality or injury, financial stability, aircraft fleet age, safety training or report programs, and other factors) as derived from key informant interviews. Surveys of industry, consumer experts, and a government panel will be conducted in order to determine the weighted value of each key indicator. Although the Federal Aviation Administration (FAA) and Air Transport Association (ATA) claim that creating such a rating would be inappropriate and misleading, we believe that this project will successfully specify the factors involved in ranking safety of U.S. major carriers, thereby benefitting the American public as well as other nations.

THE OPTICS, PIGMENTS AND PHENOLOGY OF WATER LILLIES

Kim J. Whitman, Department of Atmospheric Science and J.F. Schalles, Department of Biology, Creighton University, Omaha, Nebraska 68178.

Recently, hyperspectral measurements have been used to relate leaf optics and pigment concentrations in higher plants. Our study investigated the optical and pigment relationships in aquatic vegetation. We grew tropical and northern water lily plants in greenhouse tanks and measured leaf phenology and turnover, spectral reflectance and transmission, and pigment content. We were able to measure orderly changes in the leaf optics and pigment content as the leaf aged. VIS reflectance increased and the Xred edgeî transition decreased sharply during later stages. Chlorophyll a content varied from 1 mg * cm-2 in senescent leaves to 10-20 in young leaves to 25-45 in mature leaves. Recent NIR chlorophyll retrieval algorithms (ratio of reflectances at 750 over 700nm and 750 over 550nm; (Gitelson & Merzlyak, 1997) accurately related light reflectance to pigment content in our leaves. Further analysis of the reflectance spectra showed a correlation between the red region (Rred) and anthocyanin content. This study provides a small-scale experimental model that can lead to canopy and habitat studies of wetland communities.