Multidisciplinary optimization of a controlled space structure using 150 design variables

A controls-structures interaction design method is presented. The method coordinates standard finite-element structural analysis, multivariable controls, and nonlinear programming codes and allows simultaneous optimization of the structure and control system of a spacecraft. Global sensitivity equations are used to account for coupling between the disciplines. Use of global sensitivity equations helps solve optimization problems that have a large number of design variables and a high degree of coupling between disciplines. The preliminary design of a generic geostationary platform is used to demonstrate the multidisciplinary optimization method. Design problems using 15, 63, and 150 design variables to optimize truss member sizes and feedback gain values are solved and the results are presented. The goal is to reduce the total mass of the structure and the vibration control system while satisfying constraints on vibration decay rate. Incorporation of the nonnegligible mass of actuators causes an essential coupling between structural design variables and control design variables

SpaceOAR to improve dosimetric outcomes for monotherapy high-dose-rate prostate implantation in a patient with ulcerative colitis.

High-dose-rate (HDR) brachytherapy is an attractive option for patients receiving definitive radiation therapy for prostate cancer with decreased overall dose to the pelvis. However, ulcerative colitis increases rectal toxicity risk and may be a contraindication. A synthetic hydrogel, SpaceOAR (Augmentix Inc., Waltham, MA, USA), can facilitate the use of HDR brachytherapy for patients where rectal toxicity is a limiting factor. SpaceOAR gel (13.19 cc) was utilized in a monotherapy HDR prostate treatment with Ir-192 under transrectal ultrasound guidance, with the intention of decreasing rectal dose. SpaceOAR gel was inserted transperineally into the patient 18 days prior to the procedure. The HDR brachytherapy procedure was tolerated without incident. All planning constraints were met, and the following dosimetry was achieved: Prostate – V100% = 97.3%, V150% = 35%, V200% = 14.5%; Urethra – V118% = 0%; Rectum – D2 cc = 51.6%, V75% = 0 cc. The rectum-catheter spacing was on average between 6-8 mm. Average spacing for our 10 most recent patients without SpaceOAR was 3 mm. SpaceOAR did not hinder or distort ultrasound imaging or increase treatment time. SpaceOAR successfully increases catheter-rectal wall spacing and decreases rectal dose due to improved planning capabilities, while decreasing the likelihood of rectal perforation. One application of this tool is presented to mitigate potential toxicities associated with ulcerative colitis. At five months, one week, and one day follow-up, the patient reported no bowel issues following HDR brachytherapy. © 2018 Termedia Publishing House Ltd. All Rights Reserved

One-Litter Outdoor Farrowing System by using Artificial Insemination and Hoop Structures

The one−litter outdoor system of pork production may be improved with advanced technology. Artificial insemination and low cost gestation housing allow replacement gilts to be produced at a lower cost. Electric fencers, all terrain vehicles, and improved management all provide the hog producer an opportunity to raise more hogs at lower cost and with reduced labor. This article provides a budget for a one-litter system in which three groups of 100 sows each are farrowed annually. Seven hundred-fifty pigs are raised to 50 lb from each farrowing. Then, 300 pigs per group are saved from the maternal cross as well as six terminal boars and are finished in hoop structures. Of 900 pigs finished, 390 (130 per group) are kept for replacement gilts (using the hoops for gestation). The remaining are sold as market hogs. Of 130 gilts, 30 are assumed to be non breeders and are sold as open gilts. The remaining 100 gilts are farrowed the following year and sold immediately after weaning. This system farrows 300 litters and markets 2,250 feeder pigs, 500 market hogs, 90 cull gilts, and 300 cull sows per year. Based on current prices (1997) and 7.5 pigs weaned per litter, the cost of production was $41 per 50 lb–pig for all costs; or$32 per 50 lb–pig excluding labor. The system budget is competitive with more capital-intensive confinement systems

The Iowa Pork Production Industry—Descriptive Characteristics

The Iowa pork production industry has experienced a reduced number of producers and increased size of operation over time. Results of a survey conducted in 2002 showed that about one-in-four producers (23 percent) marketed from 5,000 to 9,999 market hogs annually. About one-in-three (31 percent) marketed from 2,000 to 4,999 pigs annually. The predominant operation type was a farrow-to-finish producer (40 percent of producers). Confinement production with mechanical ventilation was the primary type of farrowing and nursery production system used. There was a wide range of types of finishing facilities in use. Open lots with shelters or pastures represented the largest number of breeding/gestation facilities. The nearest neighbor for most producers was from one-eighth to one-half mile from the production facility. One-third had the nearest neighbor one-eighth to one-fourth mile from the facility. Slightly more than one-third had the nearest neighbor one-fourth to one-half mile from the facility. Most producers had only one hog production site. A few producers (10) had ten or more production sites. Only about six percent of the producers were under 30 years old. One-in-eight producers were 60 years old or older. About the same number had 40 or more years experience as a pork producer. Most had from 20 to 35 years of production experience

Pork Producer Efforts to Improve Neighbor Relations

As part of a pork producer odor survey conducted in 2002, respondents were asked to provide information on things they were doing to improve neighbor relations. The open-ended question provided a wide range of responses. It was evident that many producers are working with neighbors to better inform them about their pork production operation and when they may be doing activities such as applying manure, etc. Primary items producers are doing to improve neighbor relations are communication, treating them with respect, and considering weather before applying manure. This would include wind direction, air temperature, etc. Another grouping of items included manure application timing, providing pork/gifts, keeping facilities and landscaping looking nice, and facility location or siting. Producers do things to improve neighbor relations. About 30 percent indicated they check the weather before deciding to apply manure; and/or they communicate with the neighbors informing them when manure will be applied. Another one-in-six respondents indicated they use landscaping around the facility to improve its appearance

Air/Odor Control Technology Used By Iowa Pork Producers

An issue that has received attention in the livestock industry is that of air quality/odor. An Iowa pork producer survey showed that about two-thirds of the respondents felt air quality/odor was an issue that needed evaluation. This report is aimed at developing a baseline of air quality/odor control measures currently in use by Iowa pork producers. Information is obtained on use of selected odor control technologies and user level of satisfaction. Two survey methods were utilized; a mail survey and a telephone survey. The telephone survey followed the mail survey and was used to test the representativeness of the mail survey respondents and obtain information on why selected odor control technologies were not used. Level of use and level of satisfaction with selected odor control methods varied. A deep pit was used by 77 percent of the respondents. About seven-in-ten injected manure. About half of the respondents immediately incorporated manure. One-half composted pig mortalities. About four-in-ten had a windbreak, used manure additives, and/or had a bedded system somewhere in the production system. Level of satisfaction was high for windbreaks, bedded systems, bio-covers, deep pits, composting pigs/manure, and incorporating manure. Satisfaction was low for bio-filters, ozone, manure storage plastic covers, and manure additives. Reasons why odor control technologies were not used varied. A dominant reason was that the technology was not applicable to the production facility. For example, a biocover, plastic cover, etc. would not be applicable for a deep pit manure storage system. Another response for nonadoption of some technologies was that odors are managed sufficiently already. This was related to the response for building odors. About one-third of the respondents indicated they did not use selected building odor control technologies because they were too expensive and/or they were not familiar with the technology. Responses for not using modified diets and/or manure additives included too expensive, not effective for odor control, and not familiar with the technology. This survey shows that swine producers are using a wide variety of techniques to minimize off-site odor and air quality effects. The most common type of manure storage used is deep pits (68 percent of producers) followed by solid manure systems (20 percent). While a large number of technologies are available, none provides a perfect solution to air quality

The Game Saturation Number of a Graph

Given a family F and a host graph H, a graph G ⊆ H is F-saturated relative to H if no subgraph of G lies in F but adding any edge from E(H) - E(G) to G creates such a subgraph. In the F-saturation game on H, players Max and Min alternately add edges of H to G, avoiding subgraphs in F, until G becomes F-saturated relative to H. They aim to maximize or minimize the length of the game, respectively; satg(F;H) denotes the length under optimal play (when Max starts). Let O denote the family of odd cycles and the family of n-vertex trees, and write F for when F = {F}. Our results include satg(O; Kn) = [n/2] [n/2], satg(Tn; Kn) = (n-2/2) + 1 for n ≥ 6, satg(K1,3; Kn) = 2[Tn/2] for n ≥ 8, and satg(P4; Kn) ∈ {[4n/f] , [4n/5]} for n ≥ 5. We also determine satg(P4; Km;n); with m ≥ n, it is n when n is even, m when n is odd and m is even, and m + [n/2] when mn is odd. Finally, we prove the lower bound satg(C4; Kn,n) ≥ 1/21n13/12 – O(n35/36). The results are very similar when Min plays first, except for the P4-saturation game on Km,n.

Book Reviews

Reviews of the following books: Pownal: A Rural Maine History by Donna Boyles and others; Maine Genealogy: A Bibliographical Guide by John Frost; Cumberland, Maine, in Four Centuries by Phyllis S. Sweetser; History of Limington, Maine, 1668-1900 by Robert L. Taylo