Report on the formal specification and partial verification of the VIPER microprocessor

The formal specification and partial verification of the VIPER microprocessor is reviewed. The VIPER microprocessor was designed by RSRE, Malvern, England, for safety critical computing applications (e.g., aircraft, reactor control, medical instruments, armaments). The VIPER was carefully specified and partially verified in an attempt to provide a microprocessor with completely predictable operating characteristics. The specification of VIPER is divided into several levels of abstraction, from a gate-level description up to an instruction execution model. Although the consistency between certain levels was demonstrated with mechanically-assisted mathematical proof, the formal verification of VIPER was never completed

Effects of rotation and sloping terrain on fronts of density current fronts

The initial stage of the adjustment of a gravity current to the effects of rotation with angular velocity f/2 is analysed using a short time analysis where Coriolis forces are initiated in an inviscid von Kármán–Benjamin gravity current front at tF=0. It is shown how, on a time-scale of order 1/f, as a result of ageostrophic dynamics, the slope and front speed UF are much reduced from their initial values, while the transverse anticyclonic velocity parallel to the front increases from zero to O(NH0), where N=g′/H0−−−−−√ is the buoyancy frequency, and g′=gΔρ/ρ0 is the reduced acceleration due to gravity. Here ρ0 is the density and Δρ and H0 are the density difference and initial height of the current. Extending the steady-state theory to account for the effect of the slope σ on the bottom boundary shows that, without rotation, UF has a maximum value for σ=\upi/6, while with rotation, UF tends to zero on any slope. For the asymptotic stage when ftF≫1, the theory of unsteady waves on the current is reviewed using nonlinear shallow-water equations and the van der Pol averaging method. Their motions naturally split into a ‘balanced’ component satisfying the Margules geostrophic relation and an equally large ‘unbalanced’ component, in which there is horizontal divergence and ageostrophic vorticity. The latter is responsible for nonlinear oscillations in the current on a time scale f−1, which have been observed in the atmosphere and field experiments. Their magnitude is mainly determined by the initial potential energy in relation to that of the current and is proportional to the ratio \it Bu−−−−−√=LR/R0, where LR=NH0/f is the Rossby deformation radius and R0 is the initial radius. The effect of slope friction also prevents the formation of a steady front. From the analysis it is concluded that a weak mean radial flow must be driven by the ageostrophic oscillations, preventing the mean front speed UF from halting sharply at ftF∼1. Depending on the initial value of LR/R0, physical arguments show that UF decreases slowly in proportion to (ftF)−1/2, i.e. UF/UF0=F(ftF,\it Bu). Thus the front only tends to the geostrophic asymptotic state of zero radial velocity very slowly (i.e. as ftF→∞) for finite values of LR/R0. However, as LR/R0→0, it reaches this state when ftF∼1. This analysis of the overall nonlinear behaviour of the gravity current is consistent with two two-dimensional non-hydrostatic (Navier–Stokes) and axisymmetric hydrostatic (shallow-water) Eulerian numerical simulations of the varying form of the rotating gravity current. When the effect of surface friction is considered, it is found that the mean movement of the front is significantly slowed. Furthermore, the oscillations with angular frequency f and the slow growth of the radius, when ftF≥1, are consistent with recent experiments

Fourier Series Formalization in ACL2(r)

We formalize some basic properties of Fourier series in the logic of ACL2(r), which is a variant of ACL2 that supports reasoning about the real and complex numbers by way of non-standard analysis. More specifically, we extend a framework for formally evaluating definite integrals of real-valued, continuous functions using the Second Fundamental Theorem of Calculus. Our extended framework is also applied to functions containing free arguments. Using this framework, we are able to prove the orthogonality relationships between trigonometric functions, which are the essential properties in Fourier series analysis. The sum rule for definite integrals of indexed sums is also formalized by applying the extended framework along with the First Fundamental Theorem of Calculus and the sum rule for differentiation. The Fourier coefficient formulas of periodic functions are then formalized from the orthogonality relations and the sum rule for integration. Consequently, the uniqueness of Fourier sums is a straightforward corollary. We also present our formalization of the sum rule for definite integrals of infinite series in ACL2(r). Part of this task is to prove the Dini Uniform Convergence Theorem and the continuity of a limit function under certain conditions. A key technique in our proofs of these theorems is to apply the overspill principle from non-standard analysis.Comment: In Proceedings ACL2 2015, arXiv:1509.0552

Synthesis and Characterization of Novel Rhodium -Tetraphosphine Ligand Complexes.

The synthesis and characterization of novel rhodium-tetraphosphine ligand complexes have been completed. The purpose of this dissertation research was to better characterize our novel binuclear hydroformylation catalyst by synthesizing and characterizing compounds with various combinations of rhodium centers and a binucleating tetratertiary phosphine ligand, et,ph-P4 [et,ph-P4 = (Et 2PCH2CH2)(Ph)PCH2P(Ph)(CH2CH 2PEt2)]. Eight new complexes, [Rh3(rac -et,ph-P4)2](BF4)3, 17, [Rh2(meso-et,ph-P4)2](PF6)2, 26, [Rh2(rac,meso-et,ph-P4)2](Cl) 2, 26a, [Rh2(rac-et,ph-P4) 2](BF4)2, 28, [RhCl2( rac-et,ph-P4)]BF4·toluene, 32a, [RhCl 2(rac-et,ph-P4)]BF4·MeOH, 32b, [RhCl2(rac-et,ph-P4)]BF4·2DCM, 32c, and [RhCl2(rac-et,ph-P4)]BF4 ·acetone, 32d, have resulted from these research efforts and are discussed in Chapters 2--4. 31P NMR analyses of these complexes show that none of these are present in our hydroformylation catalyst, based on in situ spectroscopic studies of [Rh 2(nbd)2(rac-et,ph-P4)]2+ by Dr. Rhonda Matthews. But, we believe that the cationic monometallic dihydride, [RhH2(4-rac-et,ph-P4)] +, is one of the complexes that does form in the bimetallic hydroformylation catalysis. Compounds 32a--32d are monometallic eta 4-coordinated complexes with two cisoidal chloride ligands and various solvent molecules. They are being studied as possible olefin polymerization catalysts. To be an effective catalyst, the octahedral complex will require at least one open coordination site on the metal. This will require the activation of the complex by the removal of a chloride (Cl-) ligand and the exchange of the other Cl- ligand with an alkyl group or hydride that can initiate or sustain polymerization. The results of these preliminary polymerization studies are also discussed

EVOLUTION OF LARGE CARNIVORES DURING THE MID-CENOZOIC OF NORTH AMERICA: THE TEMNOCYONINE RADIATION (MAMMALIA, AMPHICYONIDAE)

This study describes and summarizes the Temnocyoninae (Mammalia, Carnivora), a subfamily of amphicyonid carnivores of considerable diversity and singular ecomorphology within Cenozoic faunas of North America. In temnocyonines, we see the first carnivorans to occupy an ecological niche as large cursorial predators. The subfamily is confined to the Arikareean NALMA, ranging in age from the latest early Oligocene to the early Miocene. Distributed from the Pacific Northwest to the Great Plains and Florida, there are four genera (Temnocyon, Mammacyon, Delotrochanter n. gen., Rudiocyon n. gen.) and 12 species, of which eight are newly described (Temnocyon subferox, T. fingeruti, T. macrogenys; Rudiocyon amplidens; Mammacyon ferocior; Delotrochanter petersoni, D. oryktes, D. major). Among the specimens examined are eight skulls, three with intact basicranial morphology that establish the presence of a plesiomorphic arctoid auditory region in the subfamily. Temnocyonine dentitions and postcranial skeletons reveal a blend of morphological characteristics not previously nor subsequently seen among the Carnivora. From a stem species, Temnocyon altigenis, there evolve both large hypercarnivorous (Temnocyon) and durophagous forms (Mammacyon, Delotrochanter); these genera share a derived dentition that defines the Temnocyoninae. Delotrochanter oryktes n. sp., an early Miocene species, was found in a den, suggesting a possible burrowing capability and sheltering of offspring. The John Day basin of Oregon and the central Great Plains (western Nebraska, southeast Wyoming) are the source of most temnocyonine fossils; a few have been found in southern California and Florida, indicative of a continent-wide distribution. Temnocyonines have often been confused with canids, however their basicranial anatomy places them securely within the Amphicyonidae. First discovered in the 1870s, only ~30 individuals comprise the entire record of the subfamily. Many were found in proximity to radioisotopically calibrated tuffs and ignimbrites and/or were closely associated with mammals of established biochronologic age. Thus, most species can be placed in a temporal context. With rare exception, the fossils represent isolated occurrences, hence estimates of variation within a population are lacking. Cursorial postcranial features characterize several lineages (Mammacyon, Delotrochanter) and probably were present in other temnocyonines known only from dental remains. Late Oligocene Mammacyon ferocior and early Miocene Delotrochanter oryktes evolved uniquely configured crushing cheek teeth and cursorial limbs, combining distinctive dental and skeletal traits in a manner not seen in any living carnivore. These species are interpreted as large durophagous predators with craniodental characteristics that parallel living hyaenids (Crocuta crocuta) and postcranial adaptations approaching those of cursorial canids such as the wolf (Canis lupus). Expansion of semiarid grasslands and savanna during the late Oligocene and early Miocene in the central Great Plains seems to have favored the evolution of these wide-ranging durophagous amphicyonid carnivores. Analysis of the jaws of temnocyonines employing Therrien’s method of beam analysis demonstrates pronounced bending strength focused beneath the crushing dental battery in the molar region. Similarly, the canines and mandibular symphysis manifest an ability to resist strong parasagittal, transverse, and torsional forces occurring during prey capture and feeding. Temnocyonines share a pronounced similarity in dentition with European haplocyonine beardogs, which doubtless are their sister group among the Amphicyonidae. Some haplocyonines also show cursorial tendencies. Examination of European material, however, reveals subtle dental distinctions indicating that the evolution of the two subfamilies proceeded separately yet in parallel in Europe and North America

Global Climate and the Evolution of Large Mammalian Carnivores during the Later Cenozoic in North America

Taxon ranges of larger mammalian carnivores can be grouped into seven temporal intervals during the later Cenozoic. These intervals are of varied duration and seem to correspond to periodic faunal reorganizations that accompanied the progressive climatic deterioration occurring from the late Eocene to the Pleistocene. Recent oxygen isotope records from deep-sea cores serve as proxy for the pattern of global climate during the Cenozoic and compare reasonably well with the large carnivore intervals. Intervals A, B, and the early part of C characterize a time of cooler global climate (δ18O: +1.3 to +3.0‰) following the early Eocene climatic optimum. The later part of Interval C, following the mid-Miocene climatic optimum, and Intervals D through F record a gradual climatic deterioration (δ18O: +2.0 to +3.8‰) from the mid-Miocene to early Pliocene. Interval G (δ18O: +3.8 to +5.0‰) corresponds to the extreme global cooling of the later Pliocene and Pleistocene. Glacioeustatic decline in sea level during these intervals probably made possible the entrance of migrant Eurasian carnivores and other mammals into the New World via the Bering route. The periodic emergence of this land bridge and the effect of the climatic oscillations of the later Cenozoic on the mammalian fauna appear responsible for the faunal shifts

Evolution of Large Carnivores During the Mid-Cenozoic of North America: The Temnocyonine Radiation (Mammalia, Amphicyonidae)

This study describes and summarizes the Temnocyoninae (Mammalia, Carnivora), a subfamily of amphicyonid carnivores of considerable diversity and singular ecomorphology within Cenozoic faunas of North America. In temnocyonines, we see the first carnivorans to occupy an ecological niche as large cursorial predators. The subfamily is confined to the Arikareean NALMA, ranging in age from the latest early Oligocene to the early Miocene. Distributed from the Pacific Northwest to the Great Plains and Florida, there are four genera (Temnocyon, Mammacyon, Delotrochanter n. gen., Rudiocyon n. gen.) and 12 species, of which eight are newly described (Temnocyon subferox, T. fingeruti, T. macrogenys; Rudiocyon amplidens; Mammacyon ferocior; Delotrochanter petersoni, D. oryktes, D. major). Among the specimens examined are eight skulls, three with intact basicranial morphology that establish the presence of a plesiomorphic arctoid auditory region in the subfamily. Temnocyonine dentitions and postcranial skeletons reveal a blend of morphological characteristics not previously nor subsequently seen among the Carnivora. From a stem species, Temnocyon altigenis, there evolve both large hypercarnivorous (Temnocyon) and durophagous forms (Mammacyon, Delotrochanter); these genera share a derived dentition that defines the Temnocyoninae. Delotrochanter oryktes n. sp., an early Miocene species, was found in a den, suggesting a possible burrowing capability and sheltering of offspring. The John Day basin of Oregon and the central Great Plains (western Nebraska, southeast Wyoming) are the source of most temnocyonine fossils; a few have been found in southern California and Florida, indicative of a continent-wide distribution. Temnocyonines have often been confused with canids, however their basicranial anatomy places them securely within the Amphicyonidae. First discovered in the 1870s, only ~30 individuals comprise the entire record of the subfamily. Many were found in proximity to radioisotopically calibrated tuffs and ignimbrites and/or were closely associated with mammals of established biochronologic age. Thus, most species can be placed in a temporal context. With rare exception, the fossils represent isolated occurrences, hence estimates of variation within a population are lacking. Cursorial postcranial features characterize several lineages (Mammacyon, Delotrochanter) and probably were present in other temnocyonines known only from dental remains. Late Oligocene Mammacyon ferocior and early Miocene Delotrochanter oryktes evolved uniquely configured crushing cheek teeth and cursorial limbs, combining distinctive dental and skeletal traits in a manner not seen in any living carnivore. These species are interpreted as large durophagous predators with craniodental characteristics that parallel living hyaenids (Crocuta crocuta) and postcranial adaptations approaching those of cursorial canids such as the wolf (Canis lupus). Expansion of semiarid grasslands and savanna during the late Oligocene and early Miocene in the central Great Plains seems to have favored the evolution of these wide-ranging durophagous amphicyonid carnivores. Analysis of the jaws of temnocyonines employing Therrien’s method of beam analysis demonstrates pronounced bending strength focused beneath the crushing dental battery in the molar region. Similarly, the canines and mandibular symphysis manifest an ability to resist strong parasagittal, transverse, and torsional forces occurring during prey capture and feeding. Temnocyonines share a pronounced similarity in dentition with European haplocyonine beardogs, which doubtless are their sister group among the Amphicyonidae. Some haplocyonines also show cursorial tendencies. Examination of European material, however, reveals subtle dental distinctions indicating that the evolution of the two subfamilies proceeded separately yet in parallel in Europe and North America

Management of Severe Asthma

In this summary of therapy for severe asthma there is no mention of etiologic factors. The author presumes that if infection is the primary factor in the progression to severe asthma that this will be recognized and appropriately treated. A chest x-ray must be an initial laboratory study for the recognition of pneumonia or complicating pneumothorax. However, unlike respiratory failure due to emphysema, here the specific therapy of the altered pulmonary physiology is of paramount importance

Texas Forestry Paper No. 22

Some site, stand, and tree effects on diameter growth of east texas pine treeshttps://scholarworks.sfasu.edu/texas_forestry_papers/1010/thumbnail.jp