Integrating automated structured analysis and design with Ada programming support environments

Ada Programming Support Environments (APSE) include many powerful tools that address the implementation of Ada code. These tools do not address the entire software development process. Structured analysis is a methodology that addresses the creation of complete and accurate system specifications. Structured design takes a specification and derives a plan to decompose the system subcomponents, and provides heuristics to optimize the software design to minimize errors and maintenance. It can also produce the creation of useable modules. Studies have shown that most software errors result from poor system specifications, and that these errors also become more expensive to fix as the development process continues. Structured analysis and design help to uncover error in the early stages of development. The APSE tools help to insure that the code produced is correct, and aid in finding obscure coding errors. However, they do not have the capability to detect errors in specifications or to detect poor designs. An automated system for structured analysis and design TEAMWORK, which can be integrated with an APSE to support software systems development from specification through implementation is described. These tools completement each other to help developers improve quality and productivity, as well as to reduce development and maintenance costs. Complete system documentation and reusable code also resultss from the use of these tools. Integrating an APSE with automated tools for structured analysis and design provide capabilities and advantages beyond those realized with any of these systems used by themselves

Working toward a sustainable future

Keyword: Federal policy, international policy, sustainable development, social responsibility, economic conditions, environmental protection, business, industryCitation: Hecht A., Fiksel J., & Moses M. 2014. Working toward a sustainable future. Sustainability: Science, Practice, & Policy 10(2):65-75. Published online Jan 15, 2014. http://sspp.proquest.com/archives/vol10iss2/communityessay.hecht.htmlIntroductionHow can contemporary society address the complex interaction of environmental, social, and economic forces? What factors are currently limiting the sustainability of business enterprises? How can federal and state agencies break down silos and work together to pursue sustainability? What is the preferred model for business-government collaboration and engagement with civil society and nongovernmental organizations (NGOs)? We raise these questions because in the 21st century all sectors of society must confront the challenge of sustaining economic development while protecting critical environmental resources.In 1970, when the modern environmental movement was coalescing and the United States Environmental Protection Agency (USEPA) was created, environmental protection focused mainly on addressing issues related to industrial emissions and occupational health and safety. Most environmental challenges were highly visible and easy for the public to understand. For instance, on June 22, 1969, an oil slick and debris in the Cuyahoga River in Cleveland caught fire, drawing national attention to environmental problems in Ohio and elsewhere in the United States. Time magazine wrote on August 1, 1970, "Some River! Chocolate-brown, oily, bubbling with subsurface gases, it oozes rather than flows."Congress addressed the obvious problems of air, water, and land pollution in the United States through media-specific environmental legislation. In the late 1960s and early 1970s, there was significant bipartisan popular demand for federal leadership in ameliorating pollution problems (Andrews, 2011). The Clean Air Act of 1970, the Clean Water Act of 1972, the Safe Drinking Water Act of 1974, the Resource Conservation and Recovery Act of 1976, and the Comprehensive Environmental Response, Cleanup, and Liability (Superfund) Act of 1980 yielded great progress in improving the quality of the environment. These initiatives relied on federal regulations that set maximum pollutant limits and heavily fined businesses that did not comply. The success of these laws and subsequent regulations is evident today: our air and water are cleaner, less hazardous waste is produced, and contaminated sites are being remediated. Existing regulations provide a strong "safety net" against the domestic impacts of pollution, although the potential remains for environmental problems to be "exported" across global supply chains.Despite these significant accomplishments, newly emerging pressures are threatening the well-being and resilience of human society and the natural environment, thus jeopardizing economic prosperity. The urgency of dealing with today's problems is evident. Worldwide population growth and urban development, as well as globalization of industrial production, have driven increased consumption of energy, water, materials, and land. The consequences include increased greenhouse-gas emissions, decreased biodiversity, and threats to vital natural resources including water bodies, soils, forests, wetlands, and coral reefs. The Millennium Ecosystem Assessment found that fifteen of 24 global ecosystem services are being degraded or exhausted (Hassan et al. 2005). A study by the Stockholm Center for Resilience suggests that on a planetary scale we have exceeded our "safe operating boundaries" in terms of greenhouse-gas emissions, nitrogen flows, and biodiversity (Rockstrom et al. 2009). The Global Footprint Network has estimated that if current trends continue, by the 2030s, we will need the equivalent of two Earths to support the world's population.

Maui Mesosphere and Lower Thermosphere (Maui MALT) Observations of the Evolution of Kelvin-Helmholtz Billows Formed Near 86 km Altitude

Small-scale (less than 15 km horizontal wavelength) structures known as ripples have been seen in OH airglow images for nearly 30 years. The structures have been attributed to either convective or dynamical instabilities; the latter are mainly due to large wind shears, while the former are produced by superadiabatic temperature gradients. Dynamical instabilities produce Kelvin-Helmholtz (KH) billows, which have been known for many years. However, models and laboratory experiments suggest that these billows often spawn a secondary instability that is convective in nature. While laboratory investigations see evidence of such structures, the evolution of these instabilities in the atmosphere has not been well documented. The Maui Mesosphere and Lower Thermosphere (Maui MALT) Observatory, located on Mt. Haleakala, is instrumented with a Na wind/temperature lidar that can detect dynamic or convective instabilities with 1 km vertical resolution over the altitude region from about 85 to 100 km. The observatory also includes a fast OH airglow camera, sensitive to emissions coming from approximately 82 to 92 km altitude, which obtains images every 3 s at sufficient resolution and signal to noise to see the ripples. On 15 July 2002, ripples were observed moving at an angle to their phase fronts. After a few minutes, structures appeared to form approximately perpendicular to the main ripple phase fronts. The lidar data showed that a region of dynamical instability existed from approximately 85.5 to 87 km and that the direction of the wind shear in this region was consistent with the phase fronts of the ripple features. The motion of the ripples themselves was consistent with the wind velocity at 85.9 km. Thus in this case the observed ripple motion was the advection of KH billows by the wind. The perpendicular structures were seen to be associated with the KH billows: they formed at the time when the atmosphere briefly became convectively unstable within the region where the KH billows most likely formed. Because of this and because the ripples were oriented approximately perpendicular to and moved with the billows, we speculate that they are the secondary instabilities predicted by models of KH evolution. The primary and perpendicular features were seen to decay into unstructured regions suggestive of turbulence. While the formation and decay time appear consistent with models, the horizontal wavelength of the perpendicular structures seems to be larger than models predict for the secondary instability features

TOMEX: A Comparison of Lidar and Sounding Rocket Chemical Tracer

On October 26, 2000, a Black Brant V sounding rocket carrying a chemical tracer release was launched from the rocket range at White Sands, New Mexico, as part of the Turbulent Oxygen Mixing Experiment (TOMEX). The releases occurred approximately 150 km from the location of the Starfire Optical Range where the University of Illinois sodium lidar was operated to measure winds and temperatures in the mesosphere and lower thermosphere. The geometry for the experiment was such that the lidar beam was able to intersect the release point for the chemical tracer trail on the upleg part of the flight near an altitude of 95 km. In all, a total of five lidar beam directions were used to sample the region from approximately 85 to 105-km altitude in the vicinity of the releases. Combining the lidar Doppler velocity data from the various beam directions made it possible to produce profiles of vector horizontal winds that could be compared directly with the winds obtained from the triangulation of the chemical tracer trails

Observations of Gravity Wave Breakdown into Ripples Associated with Dynamical Instabilities

The breakdown of a high-frequency quasi-monochromatic gravity wave into smallscale ripples in OH airglow was observed on the night of 28 October 2003 at Maui, Hawaii (20.7ºN, 156.3ºW). The ripples lasted ~20 min. The phase fronts of the ripples were parallel to the phase fronts of the breaking wave. The mechanism for the ripple generation is investigated using simultaneous wind and temperature measurements made by a sodium (Na) lidar. The observations suggest that the wave breaking and the subsequent appearance of ripples were related to dynamical (or Kelvin-Helmholtz) instabilities. The characteristics of the ripples, including the alignment of the phase fronts with respect to the wind shear, the motion of the ripples, and the horizontal separation of the ripple fronts were consistent with their attribution to Kelvin-Helmholtz billows. It is likely that the dynamical instability was initiated by the superposition of the background wind shear and the shear induced by the wave. The wind shear, the mean wind acceleration, and the propagation of the breaking wave were found to be in the same direction, suggesting that wave-mean flow interactions contributed significantly to the generation of the strong (\u3e40 m/s/km) wind shear and instability

Unstable Layers in the Mesopause Region Observed with Na Lidar During the Turbulent Oxygen Mixing Experiment (TOMEX) Campaign

The Na wind/temperature lidar located at Starfire Optical Range near Albuquerque, New Mexico, provided real time measurements of wind, temperature, and Na density in the mesopause region during the TOMEX rocket campaign in October 2000. The state of the atmosphere in which the rocket was launched into was examined using the lidar measurements. Both convectively and dynamically unstable layers were observed at various times and altitudes during the night. The low convective stability region below 90 km was found to be associated with the diurnal tide. The unstable layers are the combined results of wave and tidal perturbations. Comparison with the thermosphere/ionosphere/mesopshere/electrodynamics general circulation model (TIMEGCM) simulation showed that the model can produce the general feature of the observed atmospheric structure (but with a much smaller diurnal amplitude in temperature), which likely leads to underestimate of instability and gravity wave effects

TOMEX: Mesospheric and Lower Thermospheric Diffusivities and Instability Layers

The Turbulent Oxygen Mixing Experiment (TOMEX), which was carried out at White Sands Missile Range in New Mexico on 26 October 2000, included a rocketborne trimethyl aluminum (TMA) chemical tracer experiment. The subsequent TMA trails provided detailed information about the horizontal neutral wind, turbulence, and diffusivity properties of the atmosphere between approximately 85 and 140 km altitude. Measurements with the University of Illinois Na wind/temperature lidar located at the Starfire Optical Range, NM, provided a detailed time history of the stability properties between 85 and 105-km altitude, including high-resolution wind and temperature measurements prior to and during the chemical tracer measurements. The diffusivities estimated from the trail expansion rates have values consistent with the values expected for molecular diffusion above 110-km altitude and values that are larger than those for molecular diffusion at most altitudes below. Below 103 km, both regions of dynamic and convective instability were found, and the diffusivities are strongly controlled by the instabilities. The unstable regions are well mixed, but the intermediate regions, in some cases, have very small eddy energy dissipation rates. The nearly instantaneous measurements also suggest that eddy diffusion is still important in the height range between 103 km, the nominal turbopause height, and 110 km

Unstable Layers in the Mesopause Region Observed with Na Lidar During the Turbulent Oxygen Mixing Experiment (TOMEX) Campaign

The Na wind/temperature lidar located at Starfire Optical Range near Albuquerque, New Mexico, provided real time measurements of wind, temperature, and Na density in the mesopause region during the TOMEX rocket campaign in October 2000. The state of the atmosphere in which the rocket was launched into was examined using the lidar measurements. Both convectively and dynamically unstable layers were observed at various times and altitudes during the night. The low convective stability region below 90 km was found to be associated with the diurnal tide. The unstable layers are the combined results of wave and tidal perturbations. Comparison with the thermosphere/ionosphere/mesopshere/electrodynamics general circulation model (TIMEGCM) simulation showed that the model can produce the general feature of the observed atmospheric structure (but with a much smaller diurnal amplitude in temperature), which likely leads to underestimate of instability and gravity wave effects

A Boreing Night of Observations of the Upper Mesosphere and Lower Thermosphere Over the Andes Lidar Observatory

A very high-spatial resolution (∼21-23 m pixel at 85 km altitude) OH airglow imager at the Andes Lidar Observatory at Cerro Pach´on, Chile observed considerable ducted wave activity on the night of October 29-30, 2016. This instrument was collocated with a Na wind-temperature lidar that provided data revealing the occurrence of strong ducts. A large field of view OH and greenline airglow imager showed waves present over a vertical extent consistent with the altitudes of the ducting features identified in the lidar profiles. While waves that appeared to be ducted were seen in all imagers throughout the observation interval, the wave train seen in the OH images at earlier times had a distinct leading non-sinusoidal phase followed by several, lower-amplitude, more sinusoidal phases, suggesting a likely bore. The leading phase exhibited significant dissipation via small-scale secondary instabilities suggesting vortex rings that progressed rapidly to smaller scales and turbulence (the latter not fully resolved) thereafter. The motions of these small-scale features were consistent with their location in the duct at or below ∼83-84 km. Bore dissipation caused a momentum flux divergence and a local acceleration of the mean flow within the duct along the direction of the initial bore propagation. A number of these features are consistent with mesospheric bores observed or modeled in previous studies