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Tropical corn silage was compared with sorghum silage as a basal forage in the diets of high producing dairy cows. Sorghum and tropical corn silages were each included in place of ground corn at incremental concentrations in the experimental diets. Eight separate diets were fed, four diets containing each silage ranging in forage neutral detergent fiber (NDF) from approximately 25 to 31% and ranging in total NDF from approximately 41 to 45%. Diets were arranged in a 2 x 4 factorial design and were fed to lactating cows (n = 24; pretrial mean milk production = 39 kg/d; body weight = 656 kg; and days in milk = 81). As concentrations of dietary NDF increased, intake and milk production decreased linearly. The impact of dietary NDF on intake was greater for diets based on tropical corn silage than for diets based on sorghum silage. Energy intake and milk production were reduced, but cows consumed more fiber when challenged with higher dietary concentrations of fiber. The in vitro rate and extent of digestion of dietary samples were correlated with intake response. The rate of in vitro fiber digestion was slower for samples that contained tropical corn silage than for samples that contained sorghum silage. In vivo digestibility measurements were influenced by intake and dietary composition. Results of this trial indicated that sorghum silage can have equal or slightly greater nutritional value than tropical corn silage when these forages are fed at equal concentrations of dietary fiber.  相似文献   
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In this paper we propose a nonlinear control approach for the path‐tracking of an autonomous underactuated airship. A backstepping controller is designed from the airship nonlinear dynamic model including wind disturbances, and further enhanced to consider actuators saturation. Control implementation issues related to airship underactuation are also addressed, namely control allocation and an attitude reference shaping to obtain a faster error correction with smoother input requests. The results obtained demonstrate the capacity of an underactuated unmanned airship to execute a realistic mission including vertical take‐off and landing, stabilization and path‐tracking, in the presence of wind disturbances, with a single robust control law. Copyright © 2008 John Wiley & Sons, Ltd.  相似文献   
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Although numerous protein biomarkers have been correlated with advanced disease states, no new clinical assays have been developed. Goals often anticipate disease-specific protein changes that exceed values among healthy individuals, a property common to acute phase reactants. This review considers somewhat different approaches. It focuses on intact protein isoform ratios that present a biomarker without change in the total concentration of the protein. These will seldom be detected by peptide level analysis or by most antibody-based assays. For example, application of an inexpensive method to large sample groups resulted in observation of several polymorphisms, including the first structural polymorphism of apolipoprotein C1. Isoform distribution of this protein was altered and was eventually linked to increased obesity. Numerous other protein isoforms included C- and N-terminal proteolysis, changes of glycoisoform ratios and certain types of sulfhydryl oxidation. While many of these gave excellent statistical correlation with advanced disease, clinical utility was not apparent. More important may be that protein isoform ratios were very stable in each individual. Diagnosis by longitudinal analysis of the same individual might increase sensitivity of protein biomarkers by 20-fold or more. Protein changes that exceed the range of values found among healthy individuals may be uncommon.  相似文献   
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We show how to support efficient back traversal in a unidirectional list, using small memory and with essentially no slowdown in forward steps. Using O(lgn)O(lgn) memory for a list of size nn, the ii’th back-step from the farthest point reached so far takes O(lgi)O(lgi) time in the worst case, while the overhead per forward step is at most ?? for arbitrary small constant ?>0?>0. An arbitrary sequence of forward and back steps is allowed. A full trade-off between memory usage and time per back-step is presented: kk vs. kn1/kkn1/k and vice versa. Our algorithms are based on a novel pebbling technique which moves pebbles on a virtual binary, or n1/kn1/k-ary, tree that can only be traversed in a pre-order fashion.  相似文献   
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Energy windowing is an algorithmic alarm method that can be applied to plastic scintillator-based radiation portal monitor (RPM) systems to improve operational sensitivity to certain threat sources while reducing the alarm rates from naturally occurring radioactive material. Various implementations of energy windowing have been tested and documented by industry and at Pacific Northwest National Laboratory, and are available in commercial RPMs built by several manufacturers. Moreover, energy windowing is being used in many deployed RPMs to reduce nuisance alarms and improve operational sensitivity during the screening of cargo. This paper describes energy windowing algorithms and demonstrates how these algorithms succeed when applied to “controlled” experimental measurements and “real world” vehicle traffic data.  相似文献   
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The isochoric heat capacity of pure methanol in the temperature range from 482 to 533 K, at near-critical densities between 274.87 and 331.59 kg· m−3, has been measured by using a high-temperature and high-pressure nearly constant volume adiabatic calorimeter. The measurements were performed in the single- and two-phase regions including along the coexistence curve. Uncertainties of the isochoric heat capacity measurements are estimated to be within 2%. The single- and two-phase isochoric heat capacities, temperatures, and densities at saturation were extracted from experimental data for each measured isochore. The critical temperature (Tc = 512.78±0.02K) and the critical density (ρc = 277.49±2 kg · m−3) for pure methanol were derived from the isochoric heat-capacity measurements by using the well-established method of quasi-static thermograms. The results of the CVVT measurements together with recent new experimental PVT data for pure methanol were used to develop a thermodynamically self-consistent Helmholtz free-energy parametric crossover model, CREOS97-04. The accuracy of the crossover model was confirmed by a comprehensive comparison with available experimental data for pure methanol and values calculated with various multiparameter equations of state and correlations. In the critical and supercritical regions at 0.98TcT ≤ 1.5Tc and in the density range 0.35ρc ≤ ρ leq 1.65 ρc, CREOS97-04 represents all available experimental thermodynamic data for pure methanol to within their experimental uncertainties.  相似文献   
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