James E. Lumpp

Experimental Modeling of Spinal Cord Injury: Characterization of a Force-Defined Injury Device

We examined the ability of a novel spinal cord injury (SCI) device to produce graded morphological and behavioral changes in the adult rat following an injury at thoracic level 10 (T10). The injury device uses force applied to the tissue as the control variable rather than tissue displacement. This has the advantage of eliminating errors that may arise from tissue movement prior to injury. Three different injury severities, defined by the amount of force applied to the exposed spinal cord at T10 (100, 150, and 200 kdyn), were evaluated at two different survival times (7 and 42 d). Unbiased stereology was employed to evaluate morphological differences following the injury. Quantitative behavioral assessment employed the Basso, Beattie, and Bresnahan locomotive rating scale. There was a significant force-related decline in locomotive ability following the injury. Animals subjected to a 200-kdyn injury performed significantly worse than animals subjected to a 100- and 150-kdyn injury. The locomotor ability at different days post injury significantly correlated with the amount of force applied to the spinal cord. Statistical analysis revealed several significant force-related morphological differences following the injury. The greatest loss of white and gray matter occurred at the site of injury impact and extended in both a rostral and caudal direction. Animals subjected to the greatest force (200 kdyn) displayed the least amount of spared tissue at both survival times indicative of the most severe injury. The amount of spared tissue significantly correlated with the locomotor ability. This novel rodent model of SCI provides a significant improvement over existing devices for SCI by reducing variability with a constant preset force to define the injury.

A user-level checkpointing library for POSIX threads programs

Several user-level checkpointing libraries that checkpoint Unix processes have been developed. However they do not support multithreaded programs. This paper describes a user-level checkpointing library to checkpoint multithreaded programs that use the POSIX threads library provided by Solaris 2. Experiments with programs from the SPLASH-2 benchmark suite showed a 3% to 10% increase in execution time with checkpointing enabled, plus an additional overhead for saving the programs state. The checkpointing library described here is available at http://www.dcs.uky.edu//sup /spl sim//chkpt/.

Development of an Off-the-Shelf Bus for Small Satellites

KySat1 is a 1 kilogram picoclass satellite being developed by college students across the state of Kentucky. To the best of our knowledge, the KySat effort is the first by a state to develop a satellite. The consortium assembled to fund and develop KySat includes public, private and educational partners throughout Kentucky. While the primary mission of KySat1 is educational outreach, the goals of the KySat program include (1) Educational experience for secondary and post secondary students (2) Cultivate an aerospace and satellite technology base in Kentucky (3) Develop a reliable reusable satellite bus that will form the basis for future education and commercial KySat missions. The timeline for KySat1 is aggressive and off-the-shelf technology is leveraged whenever possible. This paper overviews the KySat1 design and development.

A Technique for Specifying Dynamically Reconfigurable Embedded Systems

This paper describes a framework for developing dynamically reconfiguring distributed embedded systems supporting graceful degradation. Graceful degradation allows embedded systems to reconfigure in response to faults, allowing the systems to reduce their level of service instead of suffering system failures. The approach is based on a graphical software specification technique. Software module dependency graphs are used to specify the interaction and interdependencies between software modules. Individual software modules can be specified with alternate implementations that may require different amounts of system resources. As failures occur, a system manager tracks system status and uses the dependency graphs to choose new system configurations to deploy. The proposed framework also supports traditional fault-tolerance techniques, such as fail-over programming, redundant calculations, and voting, making it an attractive alternative for the design of a wide range of embedded control applications. A high level description of the proposed system architecture as well as its fault detection and handling are presented followed by discussion of the software modeling

BIG BLUE: high-altitude UAV demonstrator of Mars airplane technology

BIG BLUE (baseline inflatable-wing glider, balloon-launched unmanned experiment) is a flight experiment envisioned, designed, built, and flown primarily by undergraduate students in the College of Engineering at the University of Kentucky. BIG BLUE was conceived as a demonstration of unique inflatable wing technologies with potential for application for Mars airplanes. On May 3, 2003, BIG BLUE achieved the first-ever deployment and curing of UV hardening inflatable wings and reached an altitude of 27.1km (89,000ft). BIG BLUE II was launched successfully on May 1, 2004 with a second-generation optimized wing design. The wings were deployed and cured to an excellent symmetric flying shape from a flight ready fuselage with an autonomous autopilot, sensor and communication systems. To date, over 100 students have participated directly in the design, fabrication and testing of BIG BLUE, exposing them to the challenge and excitement of aerospace careers. BIG BLUE is supported by the NASA Workforce Development Program which has objectives to attract, motivate, and prepare students for technological careers in support of NASA, its missions, and its research efforts. BIG BLUE provides multidisciplinary experiential learning directed specifically toward entering the aerospace workforce

BIG BLUE II: Mars Aircraft Prototype with Inflatable-Rigidizable Wings

The present paper presents work on developing and flight testing a Mars prototype aircraft using inflatable-rigidizable wings under the NASA Workforce Development program. Undergraduate student teams have developed a test vehicle to determine the feasibility of using inflatable-rigidizable wings in extra-terrestrial missions. The wings are constructed of an outer composite layer impregnated with a UV curable resin and an inner inflatable bladder. The wings are stowed in the fuselage, deploy when inflated, and rigidize with exposure to UV radiation; pressurization is not required after rigidization. Vehicle, wing and avionics designs are discussed and results from low and high altitude test flights are presented. The project culminated in a successful high altitude flight test with deployment and rigidization of the wing under Mars like conditions.

The CubeLab Standard for improved access to the International Space Station

As the International Space Station (ISS) is completed and the US shuttle fleet is retired in 2011, the NanoRacks Platform and CubeLab Standard provide a unique new opportunity for inexpensive repeatable access to the ISS for small payloads. The NanoRacks Platform serves as the interface between CubeLab Modules and the ISS while providing mechanical attachment, power, and data transfer to each Module. The CubeLab Standard defines mechanical and electrical requirements for CubeLab Modules. CubeLabs can be flown to and from the ISS on a variety of manned and unmanned vehicles to support a wide variety of micro-gravity experiments. Once aboard the ISS CubeLabs are installed in the NanoRacks Platforms. As of May 2010, two NanoRacks Platforms have been permanently installed aboard the ISS and each is capable of concurrently accommodating up to 16 CubeLabs. The CubeLab Standard leverages several well defined, well known, and supported standards to simplify access to space. In the summer and fall of 2010, the first four CubeLab Modules were operated aboard the ISS and in 2011 a series of additional CubeLabs will fly to/from the station aboard HTV-2, Progress, Soyuz, DragonLab, and the Space Shuttle flights. This paper introduces the NanoRacks Platform, the specifics of the CubeLab Standard, overviews the processes used for flight verification and operations of CubeLab Modules.1 2

Teaching in realtime wireless classrooms

This paper describes the educational opportunities and challenges of teaching in a realtime wireless classroom (WC) environment. The WC environment allows instructors to replace conventional blackboards and chalk with a collaborative, networked, portable computing environment. WCs provide a wide variety of new instructional possibilities, including collaborative presentations and whiteboard interaction, live audio and video, animated examples, independent and instructor-directed web surfing, and other powerful multimedia methods. However, making effective use of these realtime interactive capabilities is not straightforward, and there are many challenges involved with teaching in such an environment. This paper describes our practical experiences teaching in a WC the past academic year. The costs and effort needed to prepare course materials for a WC are discussed, and experiments that integrate the WC environment with a distance learning effort are reported.

Precision instrument for characterizing shape memory alloy wires in bias spring actuation

Some metallic alloys such as Nitinol (NiTi) exhibit the shape memory effect, which is suitable for generating force and displacement when the alloy changes phase during a heating and cooling cycle. These shape memory alloys are often formed into one-dimensional wires, tubes, and ribbons that are preloaded by bias springs to create inexpensive actuators for electromechanical devices. This article describes a new instrument for measuring the quasistatic characteristics of the alloy and the transient performance of bias-spring actuators when resistively heated and convectively cooled. The instrument achieves more accurate measurements by eliminating rolling friction and by sensing force and displacement in line with the bias spring and shape memory alloy wire. Data from the instrument enables calculation of stress and strain at constant temperatures and during actuation cycles.

A Low-Cost Control System for a High-Altitude UAV

The BIG BLUE project at the University of Kentucky is a test bed UAV for Mars airplane technology. A major focus of the BIG BLUE effort has been the development of a low-cost and light-weight avionics, control, and communication system to manage the aircraft and correspond with ground stations. BIG BLUE I, launched in May 2003, achieved the first successful deployment of inflatable/rigidizable wings at altitude. BIG BLUE II, launched in May 2004, had a flight-ready fuselage and control system. This paper describes the BIG BLUE project detailing the design and implementation of the avionics, control, and communication system