A New Path Planning Guidance Law For Improved Impact Time Control of Missiles and Precision Munitions

A new missile guidance law is proposed for the control of impact time which provides an improved time-to-go calculation by removing error due to trajectory curvature and also provides a family of trajectories for trajectory planning purposes. Unlike conventional optimal guidance laws, the proposed law is non explicit in time-to-go and the linearization of the engagement kinematics in order to gain a closed form solution is not necessary

Long-Term Ambient Noise Statistics in the Gulf of Mexico

Long-term omni-directional ambient noise was collected at several sites in the Gulf of Mexico during 2004 and 2005. The Naval Oceanographic Office deployed bottom moored Environmental Acoustic Recording System (EARS) buoys approximately 159 nautical miles south of Panama City, Florida, in water depths of 3200 meters. The hydrophone of each buoy was 265 meters above the bottom. The data duration ranged from 10-14 months. The buoys were located near a major shipping lane, with an estimated 1.5 to 4.5 ships per day passing nearby. The data were sampled at 2500 Hz and have a bandwidth of 10-1000 Hz. Data are processed in eight 1/3-octave frequency bands, centered from 25 to 950 Hz, and monthly values of the following statistical quantities are computed from the resulting eight time series of noise spectral level: mean, median, standard deviation, skewness, kurtosis and coherence time. Four hurricanes were recorded during the summer of 2004 and they have a major impact on all of the noise statistics. Noise levels at higher frequencies (400-950 Hz) peak during extremely windy months (summer hurricanes and winter storms). Standard deviation is least in the region 100-200 Hz but increases at higher frequencies, especially during periods of high wind variability (summer hurricanes). Skewness is positive from 25-400 Hz and negative from 630-950 Hz. Skewness and kurtosis are greatest near 100 Hz. Coherence time is low in shipping bands and high in weather bands, and it peaks during hurricanes. The noise coherence is also analyzed. The 14-month time series in each 1/3- octave band is highly correlated with other 1/3-octave band time series ranging from 2 octaves below to 2 octaves above the band\u27s center frequency. Spatial coherence between hydrophones is also analyzed for hydrophone separations of 2.29, 2.56 and 4.84 km over a 10-month period. The noise field is highly coherent out to the maximum distance studied, 4.84 km. Additionally, fluctuations of each time series are analyzed to determine time scales of greatest variability. The 14-month data show clearly that variability occurs primarily over three time scales: 7-22 hours (shipping-related), 56-282 hours (2-12 days, weather-related) and over an 8-12 month period

Corn gluten feed as a principal feed ingredient for gestating swine: effects on long term reproductive performance and energy, lysine and tryptophan utilization

Corn gluten feed (CGF) was evaluated as the primary energy and protein source for gestating sows. Eighty multiparous sows were assigned to three treatment groups for the three-parity trial. The gestation treatment diets were: corn-soybean meal fed at 1.8 kg · d[superscript] -1 (control), CGF plus soybean meal fed at 2.3 kg · d[superscript]-1 (CGF-low), and CGF plus soybean meal fed at 2.6 kg · d[superscript] -1 (CGF-high). The CGF diets (\u3e92% CGF) were based on the assumption that CGF had 80% and 70% the energy of corn, respectively. Treatment diets were increased 25% during winter. Sow reproductive performance was excellent for all treatments. Total live pigs at birth and 21 d for the three parities were not significantly different. Pigs from CGF-fed sows were smaller at birth (P \u3c.05), but subsequent pig weights did not differ. For the third parity, the CGF-low sows weighed less at breeding (P \u3c.10), before farrowing (P \u3c.01), after farrowing (P \u3c.05), and at the subsequent breeding (P \u3c.01). On the basis of the sow weights, CGF is equal to 70% the energy value of corn for sows;The energy value of CGF and apparent digestibility coefficients (ADC) of its components were determined using seven multiparous sows (d 60-75 gestation) in metabolism stalls. The diet was 97% CGF fed at 2.6 kg · d[superscript]-1. Determined CGF energy values were: 3552 kcal/kg DE, (12.5% CV), 3308 kcal/kg ME, (16.9% CV), and 3244 kcal/kg ME[subscript] n (14.6% CV). CGF ADCs were: N, 72.3% (27 SEM); EE, 35.4% (29 SEM); NDF, 51.6% (22 SEM); ADF, 47.4% (21 SEM); cellulose, 54.3% (16 SEM); and hemicellulose, 51% (26 SEM);Two trials, each with six multiparous sows in 6 x 6 Latin square designs, were used to determine the required LYS or TRP supplementation of CGF diets. Sows (d 30 gestation) in metabolism stalls were fed 2.6 kg · d[superscript]-1 (97% CGF). Graded levels of supplemental amino acids in Trial 1 were 0,.55, 1.09, 1.65, 2.19, and 2.73 g · d[superscript]-1 LYS and in Trial 2 were 0,.28,.59,.91, 1.19, and 1.50 g · d[superscript]-1 TRP. In Trial 1, increasing LYS intakes decreased (P \u3c.10) urine urea N (quadratic) and fasting plasma urea N (linear) and increased (P \u3c.10) postprandial plasma LYS (quadratic). In Trial 2, increasing TRP intakes linearly increased fasting (P \u3c.01) and postprandial (P \u3c.0001) plasma TRP. CGF can meet or nearly meet the LYS, TRP, and energy needs of gestating sows and current values underestimate the contribution of CGF in sow diets

Foundations of coverage algorithms in autonomic mobile sensor networks

Drones are poised to become a prominent focus of advances in the near future as hardware platforms manufactured via mass production become accessible to consumers in higher quantities at lower costs than ever before. As more ways to utilize such devices become more popular, algorithms for directing the activities of mobile sensors must expand in order to automate their work. This work explores algorithms used to direct the behavior of networks of autonomous mobile sensors, and in particular how such networks can operate to achieve coverage of a field using mobility. We focus special attention to the way limited mobility affects the performance (and other factors) of algorithms traditionally applied to area coverage and event detection problems. Strategies for maximizing event detection and minimizing detection delay as mobile sensors with limited mobility are explored in the first part of this work. Next we examine exploratory coverage, a new way of analyzing sensor coverage, concerned more with covering each part of the coverage field once, while minimizing mobility required to achieve this level of 1-coverage. This analysis is contained in the second part of this work. Extending the analysis of mobility, we next strive to explore the novel topic of disabled mobility in mobile sensors, and how algorithms might react to increase effectiveness given that some sensors have lost mobility while retaining other senses. This work analyzes algorithm effectiveness in light of disabled mobility, demonstrates how this particular failure mode impacts common coverage algorithms, and presents ways to adjust algorithms to mitigate performance losses. --Abstract, page iv

Type Directed Specification Refinement

Specification languages serve a fundamentally different purpose than general-purpose programming languages, and their type systems reflect these needs. Specification type systems must record and track more information for us to reason about a system adequately, and this added expressiveness may lead to an undecidable typing analysis. System level design begins with a high-level specification that is continually refined and expanded with implementation details, constraints, and typing information, down to a concrete specification. During this refinement process, the system is underspecified, and many static analyses aren't applicable until the system is fully specified. However, partial specifications contain valuable information that can inform the refinement process--we can locally inspect parts of the specification from a typing perspective to look for inferrable information or inconsistencies early on to aid the refinement process. This work defines a typing analysis that gathers constraints and typing information to inform the specification refinement process. It explores localized techniques such as local type inference and tracking of values as a means of influencing the specification refinement process