239 Body Weight and Growth in Normal Cyclic and Acyclic Gilts

Anestrus, or failure to express estrus during boar exposure, is commonly observed in replacement gilts, and results primarily from either delayed onset of puberty (prepubertal; PP) or cyclic ovulations without behavioral estrus (behavioral anestrus; BA). Gilts born between 2007 and 2018 at USMARC were observed for age at puberty between 160 and 240 days of age. Mature boars were placed in an alleyway pen while a herdsman observed gilts for standing lordosis in response to the back pressure test. Gilts failing to be observed in estrus by 240 days of age were slaughtered (250.4 ± 0.3 days of age) and reproductive tracts recovered to determine if gilts had ovulated. Gilts were defined as PP (n = 606), BA (n = 649), or Peripubertal (n = 118; PP with large preovulatory follicles on the ovary). There were 96 age-matched, cyclic contemporary gilts included as cyclic control gilts. Body weights were recorded at birth, weaning, 8 weeks, and 21 weeks of age with hot carcass weight (HCW) recorded at slaughter. The objective was to retrospectively determine if growth and HCW differed between these groups. Data were analyzed as a mixed ANOVA using group as a fixed effect with sire and farrowing group to which the gilt was born as random effects. Birth weight, weaning weight, ADG at weaning, and weight at 8 weeks did not differ between groups (P > 0.16). The BA gilts had greater growth rate (weight per day of pig age at 21 weeks; P < 0.02) and HCW (P < 0.0001) than PP and Peripubertal gilts, which also had smaller HCW than control gilts. Some cyclic control gilts (7.3%) that displayed estrous behavior had a prepubertal reproductive tract with no ovulatory activity at slaughter. Results indicated that gilts exhibiting delayed puberty grow slower late in development and during boar exposure. Estrus without ovulation in replacement gilts may be more prevalent than assumed. USDA is an equal opportunity provider and employer.

Formally Validating a Practical Verification Condition Generator

A program verifier produces reliable results only if both the logic used to justify the program’s correctness is sound, and the implementation of the program verifier is itself correct. Whereas it is common to formally prove soundness of the logic, the implementation of a verifier typically remains unverified. Bugs in verifier implementations may compromise the trustworthiness of successful verification results. Since program verifiers used in practice are complex, evolving software systems, it is generally not feasible to formally verify their implementation.In this paper, we present an alternative approach: we validate successful runs of the widely-used Boogie verifier by producing a certificate which proves correctness of the obtained verification result. Boogie performs a complex series of program translations before ultimately generating a verification condition whose validity should imply the correctness of the input program. We show how to certify three of Boogie’s core transformation phases: the elimination of cyclic control flow paths, the (SSA-like) replacement of assignments by assumptions using fresh variables (passification), and the final generation of verification conditions. Similar translations are employed by other verifiers. Our implementation produces certificates in Isabelle, based on a novel formalisation of the Boogie language.

Effects of Hover Symbology Display Scaling on Performance and Workload

Rotorcraft symbology can provide pilots with the flight information necessary to replace the visual cues lost when operating in degraded visual environments. However, tuning symbology for effective use is a time-consuming process as it generally requires considerable in-flight testing and extensive trial and error. In this work, two experiments are conducted to assess how changes in the display scaling of a position–velocity–acceleration architectured symbology set affects pilot performance and workload. In the first experiment, participants attempt a modified single-axis precision hover using a simulated helicopter and nonconformal symbology set while display parameters relating to acceleration, velocity, and position cue scaling are varied. Performance is measured using the root mean square of the position error relative to a target location, and participant workload is assessed using their cyclic control activity and Bedford ratings. In the second experiment, an analytical pilot-in-the-loop simulation is conducted to validate the performance results obtained in the first experiment and to investigate the underlying system characteristics that contribute the observed trends. For the implemented symbology and Bell UH-1H model, the results from both experiments concur that a combination of low-to-mid range acceleration cue scaling and mid-to-high range position cue scaling enable strong performance without inflating workload. Results indicate an insensitivity to velocity vector scaling, likely due to the symbology architecture and nature of the control task. The results of these experiments establish a predictable relationship between display scaling and pilot response, which can aid in streamlining the tuning process for similarly-styled symbology, helicopter and task envelope combinations.

Control Optimization of Pump Cycles in Onshore Oilfields With Network and Electric Power Constraints

In onshore oilfields, sucker rod pumps are deployed to lift fluids from wells to the surface, which are then transferred by a pipeline network to a central facility. Each pump operates according to a cyclic control policy that alternates between a period of production and a period of recess, allowing the reservoir to replenish the fluids. To minimize the peak in the electric power drawn by the sucker rods, previous works have considered the scheduling of the control policies over time. However, when the production system sprawls over a large area, the energy required to force the flow through the pipelines and the pressure drops are significant. To this end, this article develops mixed-integer nonlinear formulations and mixed-integer linear approximations for baseline control-policy scheduling and reconfiguration.

Monitoring the impact of blasting operations on the environment – new solutions

Blasting operations carried out in open-cast mines generate seismic vibrations, which can adversely influence nearby structures. As a result, open-cast mines undertake measures to define the conditions for the execution of blasting operations, which are safe for the surroundings as well as documenting the level of this impact. Documenting the seismic interference through cyclic control measurements and the assessment of this interference carries one disadvantage, which is its periodic implementation. This drawback is eliminated by applying seismic monitoring. In Poland, the influence of blasting on the surroundings is monitored by a system called Mine Vibration Monitoring Station (MVMS). The system was designed and built at the AGH University of Science and Technology in Krakow and has been modernized and updated over the last few years. Presently, it is a remotely controlled system which maintains communication via the internet, with data collected at the central server of the University. Evolution of the system and its technical capabilities are presented in the article.