LOGIC BASED INFORMATION SYSTEM SPECIFICATION VERIFICATION

The purpose of this paper is to present the logic-based approach to the problem of automatic verification of the different specifications of an information system. The data flow analysis method and its basic product, data flow diagrams (DFDs), are used as an example. A traditional approach to automated DFD verification is illustrated. In this approach, DFDs are represented by database logical files, and verification rules are implemented as data manipulation procedures. Next described is the logic-based approach. First, the DFD verification problem is conceptualized. Then it is described in terms of logic, as implemented in Prolog. A comparison of the two approaches is made by looking at respective implementations of a particular DFD verification policy. Advantages of the logic-based approach are discussed, and its usefulness for the automatic verification of other system descriptions, like data dictionary or conceptual data models is pointed out

Suppletive (?) tonal alternations in Munken

The Munken dialect of Mungbam (ISO mij; Benue-Congo, Cameroon) employs tone lexically and gramatically, contrasting four level tones as well as contours. Noun stems undergo tonal alternations conditioned by the tone of a following possessive pronoun. For some of these alternations it is not obvious that they represent a phonetically natural allophonic process. Furthermore, similar alternations are not observed outside of the possessive construction. If the alternation is suppletive, then Munken would represent a case of phonologically conditioned suppletive allomorphy (PCSA). Tonally conditioned PCSA is only rarely reported, and until now not for any African language

On Speleosiro argasiformis—a troglobitic Cyphophthalmi (Arachnida: Opiliones: Pettalidae) from Table Mountain, South Africa

We report the recent collection and observation of large numbers of specimens of the troglobitic harvestman Speleosiro argasiformis Lawrence 1931 in the Wynberg Cave system, Table Mountain, South Africa. Specimens were collected and/or photographed in different caves of the system. Live observation showed specimens fleeing bat carcasses when disturbed.Organismic and Evolutionary Biolog

Estimation of Potential Aircraft Fuel Burn Reduction in Cruise Via Speed and Altitude Optimization Strategies

Environmental performance has become a dominant theme in all transportation sectors. As scientific evidence for global climate change mounts, social and political pressure to reduce fuel burn and CO2 emissions has increased accordingly, especially in the rapidly growing aviation industry. Operational improvements offer the ability to increase the performance of any aircraft immediately, by simply changing how the aircraft is flown. Cruise phase represents the largest portion of flight, and correspondingly the largest opportunity for fuel burn reduction. This research focuses on the potential efficiency benefits that can be achieved by improving the cruise speed and altitude profiles operated by flights today. Speed and altitude are closely linked with aircraft performance, so optimizing these profiles offers significant fuel burn savings. Unlike lateral route optimization, which simply attempts to minimize the distance flown, speed and altitude changes promise to increase the efficiency of aircraft throughout the entire flight. Flight data was collected for 257 flights during one day of domestic US operations. A process was developed to calculate the cruise fuel burn of each selected flight, based on aircraft performance data obtained from Piano-X and atmospheric data from NOAA. Improved speed and altitude profiles were then generated for each flight, representing various levels of optimization. Optimal cruise climbs and step climbs of 1,000 and 2,000 ft were analyzed, along with optimal and LRC speed profiles. Results showed that a maximum fuel burn reduction of 3.5% is possible in cruise given complete altitude and speed optimization; this represents 2.6% fuel reduction system-wide, corresponding to 300 billion gallons of jet fuel and 3.2 million tons of CO2 saved annually. Flights showed a larger potential to improve speed performance, with nearly 2.4% savings possible from speed optimization compared to 1.5% for altitude optimization. Few barriers exist to some of the strategies such as step climbs and lower speeds, making them attractive in the near term. As barriers are minimized, speed and altitude trajectory enhancements promise to improve the environmental performance of the aviation industry with relative ease

Bet-hedging, seasons and the evolution of behavioral diversity in Drosophila

Organisms use various strategies to cope with fluctuating environmental conditions. In diversified bet-hedging, a single genotype exhibits phenotypic heterogeneity with the expectation that some individuals will survive transient selective pressures. To date, empirical evidence for bet-hedging is scarce. Here, we observe that individual Drosophila melanogaster flies exhibit striking variation in light- and temperature-preference behaviors. With a modeling approach that combines real world weather and climate data to simulate temperature preference-dependent survival and reproduction, we find that a bet-hedging strategy may underlie the observed inter-individual behavioral diversity. Specifically, bet-hedging outcompetes strategies in which individual thermal preferences are heritable. Animals employing bet-hedging refrain from adapting to the coolness of spring with increased warm seeking that inevitably becomes counterproductive in the hot summer. This strategy is particularly valuable when mean seasonal temperatures are typical, or when there is considerable fluctuation in temperature within the season. The model predicts, and we experimentally verify, that the behaviors of individual flies are not heritable. Finally, we model the effects of historical weather data, climate change, and geographic seasonal variation on the optimal strategies underlying behavioral variation between individuals, characterizing the regimes in which bet-hedging is advantageous.Physic

N+3 Aircraft Concept Designs and Trade Studies

Appendices A to F present the theory behind the TASOPT methodology and code. Appendix A describes the bulk of the formulation, while Appendices B to F develop the major sub-models for the engine, fuselage drag, BLI accounting, etc

The Scope and Practice of Rural Nurse Practitioners in Central Illinois

In today\u27s atmosphere of escalating health care costs, limited access to health care, and changes in the health care delivery systems, it is necessary to evaluate the roles and responsibilities of non physician health care providers. The advanced Nurse Practitioner is one such health care professional who currently provides vital services to the public. However, utilization of Nurse Practitioners has been limited within Illinois. The purpose of this study was to: 1) examine current perceived roles of rural Central Illinois Nurse Practitioners, and 2) determine perceived practice-related changes and trends for the future