Reducing the complexity of the software design process with object-oriented design

Designing software is a complex process. How object-oriented design (OOD), coupled with formalized documentation and tailored object diagraming techniques, can reduce the complexity of the software design process is described and illustrated. The described OOD methodology uses a hierarchical decomposition approach in which parent objects are decomposed into layers of lower level child objects. A method of tracking the assignment of requirements to design components is also included. Increases in the reusability, portability, and maintainability of the resulting products are also discussed. This method was built on a combination of existing technology, teaching experience, consulting experience, and feedback from design method users. The discussed concepts are applicable to hierarchal OOD processes in general. Emphasis is placed on improving the design process by documenting the details of the procedures involved and incorporating improvements into those procedures as they are developed

An improved dual-frequency technique for the remote sensing of ocean currents and wave spectra

A two frequency microwave radar technique for the remote sensing of directional ocean wave spectra and surface currents is investigated. This technique is conceptually attractive because its operational physical principle involves a spatial electromagnetic scattering resonance with a single, but selectable, long gravity wave. Multiplexing of signals having different spacing of the two transmitted frequencies allows measurements of the entire long wave ocean spectrum to be carried out. A new scatterometer is developed and experimentally tested which is capable of making measurements having much larger signal/background values than previously possible. This instrument couples the resonance technique with coherent, frequency agility radar capabilities. This scatterometer is presently configured for supporting a program of surface current measurements

Increasing productivity through Total Reuse Management (TRM)

Total Reuse Management (TRM) is a new concept currently being promoted by the NASA Langley Software Engineering and Ada Lab (SEAL). It uses concepts similar to those promoted in Total Quality Management (TQM). Both technical and management personnel are continually encouraged to think in terms of reuse. Reuse is not something that is aimed for after a product is completed, but rather it is built into the product from inception through development. Lowering software development costs, reducing risk, and increasing code reliability are the more prominent goals of TRM. Procedures and methods used to adopt and apply TRM are described. Reuse is frequently thought of as only being applicable to code. However, reuse can apply to all products and all phases of the software life cycle. These products include management and quality assurance plans, designs, and testing procedures. Specific examples of successfully reused products are given and future goals are discussed

Internal Migration and Regional Population Dynamics in Europe: Switzerland Case Study

This paper reports on internal migration and regional population dynamics in Switzerland. It examines briefly the main population trends in the last century and then turns to more detailed examination of internal migration patterns and trends in three years, 1984, 1994 and 1996 and compares them. First, inter-cantonal migration is investigated in the context of the life course. On the communal level population change patterns and underlying in-, out- and net migration are examined. An attempt is made to link migration with such variables as population density, level of unemployment, prevailing language and with a functional classification of the urban system. The methodology used is the same as in a number of other studies, making the results as comparable as possible with the results of other studies of migration in European states (Rees and Kupiszewski 1999)

TESLA Polarimeters

We describe a study of high-energy Compton beam polarimeters for the future e+e- linear collider machine TESLA. A segment of the beam delivery system has been identified, which is aligned with the e+e- collision axis and which has a suitable configuration for high-quality beam polarization measurements. The laser envisaged for the polarimeter is similar to an existing facility at DESY. It delivers very short pulses in the 10 ps, 10-100uJ regime and operates with a pattern that matches the pulse and bunch structure of TESLA. This will permit very fast and accurate measurements and an expeditious tune-up of the spin manipulators at the low-energy end of the linac. Electron detection in the multi-event regime will be the principle operating mode of the polarimeter. Other possible operating modes include photon detection and single-event detection for calibration purposes. We expect an overall precision of dP/P=0.5% for the measurement of the beam polarization.Comment: 8 pages, 4 figures, Presented at NATO Advanced Research Workshop on Spin Structure of the Nucleon, June 29-July 4, 2002, Nor-Amberd, Armeni

CSI Flight Computer System and experimental test results

This paper describes the CSI Computer System (CCS) and the experimental tests performed to validate its functionality. This system is comprised of two major components: the space flight qualified Excitation and Damping Subsystem (EDS) which performs controls calculations; and the Remote Interface Unit (RIU) which is used for data acquisition, transmission, and filtering. The flight-like RIU is the interface between the EDS and the sensors and actuators positioned on the particular structure under control. The EDS and RIU communicate over the MIL-STD-1553B, a space flight qualified bus. To test the CCS under realistic conditions, it was connected to the Phase-0 CSI Evolutionary Model (CEM) at NASA Langley Research Center. The following schematic shows how the CCS is connected to the CEM. Various tests were performed which validated the ability of the system to perform control/structures experiments

Using Unmanned Aerial Systems for Deriving Forest Stand Characteristics in Mixed Hardwoods of West Virginia

Forest inventory information is a principle driver for forest management decisions. Information gathered through these inventories provides a summary of the condition of forested stands. The method by which remote sensing aids land managers is changing rapidly. Imagery produced from unmanned aerial systems (UAS) offer high temporal and spatial resolutions to small-scale forest management. UAS imagery is less expensive and easier to coordinate to meet project needs compared to traditional manned aerial imagery. This study focused on producing an efficient and approachable work flow for producing forest stand board volume estimates from UAS imagery in mixed hardwood stands of West Virginia. A supplementary aim of this project was to evaluate which season was best to collect imagery for forest inventory. True color imagery was collected with a DJI Phantom 3 Professional UAS and was processed in Agisoft Photoscan Professional. Automated tree crown segmentation was performed with Trimble eCognition Developer’s multi-resolution segmentation function with manual optimization of parameters through an iterative process. Individual tree volume metrics were derived from field data relationships and volume estimates were processed in EZ CRUZ forest inventory software. The software, at best, correctly segmented 43% of the individual tree crowns. No correlation between season of imagery acquisition and quality of segmentation was shown. Volume and other stand characteristics were not accurately estimated and were faulted by poor segmentation. However, the imagery was able to capture gaps consistently and provide a visualization of forest health. Difficulties, successes and time required for these procedures were thoroughly noted

CJK- Improved LO Parton Distributions in the Real Photon and Their Experimental Uncertainties

A new analysis of the radiatively generated, LO quark (u,d,s,c,b) and gluon densities in the real, unpolarized photon, improved in respect to our paper [1], is presented. We perform four new global fits to the experimental data for F2^gamma, two using a standard FFNS approach and two based on ACOT(chi) scheme [2], leading to the FFNS(CJK) and CJK models. We also present the analysis of the uncertainties of the new CJK 2 parton distributions due to the experimental errors, the very first such analysis performed for the photon. This analysis is based on the Hessian method, for a comparison for chosen cross-sections we use also the Lagrange method.Comment: Prepared for Photon 2003: International Conference on the Structure and Interactions of the Photon (Including the 15th International Workshop on Photon-Photon Collisions), Frascati (Italy), 7-11 April 2003; 10 pages, Latex using espcrc2 style, 1 tex and 5 postscript figures; FORTRAN programs available at http://www.fuw.edu.pl/~pjank/param.htm

Heavy Quark Production at a Linear e^+e^- and Photon Collider and its Sensitivity to the Gluon Content of the Photon

A high energy linear e^+e^- collider (LC) can also be used as a Photon Collider (PC), using Compton scattering of laser photons on the e^+/e^- beams. The leading order cross-section for the production of heavy quarks, e^+e^- -> e^+e^- Q(\bar{Q}) X, at high transverse momenta is calculated for both LC and PC modes. The sensitivity of this process to the parton distribution parametrizations of real photons, especially the gluon content, is tested for both modes.Comment: 8 pages, Latex using epsfig.sty, including 6 postscript figures. Contribution to Proceedings of the Workshop "Physics Studies for a Future Linear Collider", Rolf Heuer, Francois Richard and Peter Zerwas Eds., 2000, DESY 123