2,576 research outputs found
Performance Analysis of Farrow Structure Based FBMC-OQAM System
No full textAbstractFarrow structure is used in the efficient implementation of high order filters. The number of unknown coefficients is much less in Farrow structure based implementation, in comparison with the direct form implementation of FIR filters. Some predefined multipliers can also be used in this method. Since they are known apriori they will not add much to the complexity of the system. It is seen that a relatively strong correlation exists among the adjacent impulse response coefficients of the frequency selective filters. This fact is exploited in the Farrow structure to reduce the number of multipliers required for the implementation of desired filter. And these Farrow coefficients are used for representing the polyphase components of the desired filter. This Farrow structure based prototype filter is used for implementing an FBMC-OQAM system. BER performance of Farrow structure based FBMC-OQAM system is studied and found comparable with that of existing FBMC-OQAM system
Linear-phase FIR interpolation, decimation, and M th-band filters utilizing the farrow structure
No full textThis paper introduces novel linear-phase finite-impulse response (FIR) interpolation, decimation, and Mth-band filters utilizing the Farrow structure. In these new overall filters, each polyphase component (except for one term) is realized using the Farrow structure with a distinct fractional delay. The corresponding interpolation/decimation structures can therefore be implemented using only one set of linear-phase FIR subfilters and one set of multipliers that correspond to the distinct fractional delays. The main advantage of the proposed structures is that they are flexible as to the conversion factors, and this also for an arbitrary set of integer factors, including prime numbers. In particular, they can simultaneously implement several converters at a low cost. The proposed filters can be used to generate both general filters and Mth-band filters for interpolation and decimation by the integer factor M. (In this paper, a general filter for interpolation and decimation by M means a filter having a bandwidth of approximately p/M without the restriction that p/M be included in the transition band. This is in contrast to ah Mth-band filter whose transition band does include p/M.) In both cases, the overall filter design problem can be posed as a convex problem, the solution of which is globally optimum. Design examples are included in the paper illustrating the properties and potentials of the proposed filters. © 2005 IEEE.</p
AN ECONOMIC EVALUATION OF LOW INVESTMENT SWINE PRODUCTION SYSTEMS
No full textThis publication summarizes an evaluation of smaller and lower investment swine production systems. The systems analyzed range from pasture operations with production during the warmer months to rather intense year-round use of remodeled buildings. In each case the system emphasizes use of facilities that can be constructed and remodeled by the farm operator. The report includes one section for each type of hog production: feeder pig production, farrow-to-finish operations and hog finishing.Livestock Production/Industries,
Generating an Equation to Predict Post- Farrow Maternal Weight in Multiple Parity Sows
No full textost-farrow maternal weight is required when partitioning maternal and fetal weight gains throughout gestation. Equations were developed from the analysis of 150 females (Line 1050, PIC, Hendersonville, TN) to predict the weight of conceptus by difference of pre- and post-farrowing weight change in multi-parity sows. Females were individually weighed as they were moved into the farrowing house at d 110 to 112 of gestation and again at 12 to 24 h after farrowing. Data were divided into 4 groups: (1) parity 1 sows; (2) parity 2 sows; (3) parity 3 sows; and (4) parity 4+ sows. Each group tested 3 predictor variables: pre-farrow weight, total born, and difference in days between the pre- and post-farrow weights. Prediction equations were then developed using models with significant terms based on the Bayesian Information Criterion (BIC). The optimum equations to predict maternal body weight were similar for all parities except for the intercept (b) and can be described as:Post-farrow maternal body weight (lb) = b + (0.897 × pre-farrow BW, lb) - (1.118 × total born, n) + (6.87 × days pre to post-farrow, d)Where the intercept (b) for parities 1, 2, 3, and 4+ were -5.93, 5.15, 11.90, and 32.31, respectively.The prediction equations were then used to estimate post-farrow maternal BW using 332 mixed parity sows (PIC 1050). Pre-farrow weights were taken on d 113 of gestation and maternal BW was taken within 24 h of farrowing. On average, the predicted postfarrow maternal BW was overestimated by 3.3 lb of the actual. Management practices differed in how females were fed from the validation experiment, possibly contributing to the overestimating of post-farrow maternal BW. This indicates that further evaluation of the equation is needed to see if the difference is due to litter size, parity distribution, or feeding management practices
Distribution of Salmonella serovars in breeding, nursery, and grow-to-finish pigs, and risk factors for shedding in ten farrow-to-finish swine farms in Alberta and Saskatchewan
No full textThe study objectives were to investigate Salmonella prevalence, serovar distribution, and risk factors for shedding in 10 purposively selected farrow-to-finish farms in Saskatchewan and Alberta. Pooled fecal samples from the breeding and growfinish phases and individual fecal samples from breeding, nursery, and grow-finish pigs were cultured for Salmonella; serotyping of isolates was performed. Pig and pen characteristics were recorded for each pig and pen sampled. Overall, 407/1143 (36%) of samples were Salmonella positive; within-farm prevalence ranged from 1% to 79%. Sows, nursery, and grow-finish pigs accounted for 43%, 29%, and 28% of positive samples, respectively. More Salmonella were detected in pooled pen than individual pig samples (P<0.001). Among 418 Salmonella isolates, there were 19 distinct serovars; the most common were S. Derby (28.5%), S. Typhimurium, var. Copenhagen (19.1%), S. Putten (11.8%), S. Infantis (6.8%), and S. Mbandaka (6.1%). Sows were more likely to shed Salmonella than nursery or grow-finisher (OR 2.9, P<0.001) pigs. Pelleted feed (OR 8.2, P<0.001) and nose-to-nose pig contact through pens (OR 2.2, P=0.005) were associated with increased Salmonella prevalence. Significant differences in serovar distribution were detected among production phases. The use of pooled pen samples is recommended as a more efficient means for accurate evaluation of Salmonella status in different phases of pig production. The breeding herd might be an important source of Salmonella persistence within farrow-to-finish farms and should be targeted in control efforts. The latter might also apply to the use of pelleted feed, which remains the most consistently reported significant risk factor for Salmonella shedding in pigs.Accession Number: 20103196664. Publication Type: Journal Article. Language: English. Language of Summary: French. Number of References: 32 ref. Subject Subsets: Veterinary Science; Veterinary Science; Animal Nutrition; Pig Scienc
Capturing and visualizing transient X-ray wavefront topological features by single-grid phase imaging
No full textAbstract not availableKaye S. Morgan, Timothy C. Petersen, Martin Donnelley, Nigel Farrow, David W. Parsons and David M. Pagani
Seward's folly: a new look at the Alaska Purchase
No full textIncludes bibliographical references and index.The Alaska Purchase--denounced at the time as 'Seward's Folly' but now seen as a masterstroke--is well known in American history. But few know the rest of the story. Lee Farrow offers a detailed account of just what the Alaska Purchase was, how it came about, its impact at the time, and more. Farrow shows why both America and Russia had plenty of good reasons to want the sale to occur, including Russia's desire to let go of an unprofitable, hard-to-manage colony and the belief in the United States that securing Alaska could help the nation gain control of British Columbia and generate closer trade ties with Asia . Farrow also delves into the implications of the deal for foreign policy and international diplomacy far beyond Russia and the United States at a moment when the global balance of power was in question.--Provided by publisher.Some mysterious sympathy: the foundations of friendship -- Evident advantages: origins and objectives -- Seward's chimerical project: public reaction and ratification -- No longer Russian America: taking possession of Alaska -- Paying for the "new national ice-house": approval and appropriation -- Very uneasy and vexed: international reactions to the purchase -- That snow-bound wilderness: from treaty to territory
Design and FPGA implementation of a high-speed transposed Farrow structure for arbitrary resampling in digital receivers
No full textSample rate conversion is a fundamental operation performed in the digital front-end of software-defined radio and all-digital receivers. Within this context, polynomial-based filters, such as the Farrow structure and its variants, are a sound solution when arbitrary resampling is required. This paper presents a design methodology and the results of the implementation on a field-programmable gate array (FPGA) device for a high-speed transposed Farrow structure based on a novel parallel architecture. The implemented architecture supported an input sample rate of up to 2.184 GHz with moderate utilization of the FPGA resources. Furthermore, signal-to-noise ratio and spurious-free dynamic range values higher than 87 dB and 98 dB were reported over a wide range of sample rate conversion factors. Our results may suggest an improvement in the tradeoff between flexibility, complexity and throughput compared with previous work in the field
Selected haymeal kinds in feeding farrow sows
No full textОценивали пригодность трех видов сенной муки худшего качества в кормлении супоросных свиноматок содержимых в условиях промышленного животноводческого комплекса. Опытные свиноматки (79) были разделены на четыре группы. Свиноматок контрольной группы (IV) кормили исключительно стандартным комбикормом ПР, а свиноматок опытных групп содержали на сниженных количествах кормосмесей с прибавкой 1 кг сенной муки овсяницы с люцерной (I группа), клевера плевелом многолетним (II группа) или одного плевела многолетнего (III группа). Полученные результаты показали возможность значительной экономии комбикорма ПР в кормлении супоросных свиноматок за счет введения в рацион сенной муки, особенно клевера с плевелом многолетним и одного плевела многолетнего.The suitability of three kinds of low-quality haymeal in feeding of farrow sows under industrial-type farm conditions was estimated. Experimental 79 sows were divided into four groups. Sows of the control group IV were fed exclusively the standard PR concentrated feed mixture, whereas sows of experimental groups lowered amounts of the above mixture with addition of 1 kg of haymeal prepared from the fescue-alfalfa mixture (group I), from the clover-ryegrass mixture (group II) and from only ryegrass (group III). The experiment results have proved the possibility of a considerable economy of the PR concentrated feed mixture in feeding farrow sows on the cost of haymeal, particularly of that prepared from clover-ryegrass mixture or from sole ryegrass
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