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The use of mathematics in software quality assurance

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Frontiers of Computer Science 2012年第1期6卷 3-16页

作者： david Lorge PARNAS Middle Road Software Inc. Ottawa K1V 1V5 Canada

The use of mathematics for documenting, in- specting, and testing software is explained and illus- trated. Three measures of software quality are described and discussed. Then three distinct complementary approaches to software quality assurance are presented. A case study, the testing and inspection of a safety-critical system, is discussed in detail.

关键词： software quality assurance documentationbased inspection documentation based testing

Concept of a Pitot Tube Able to Detect Blockage by Ice, Volcanic Ash, Sand and Insects, and to Clear the Tube

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Photonic Sensors 2015年第4期5卷 298-303页

作者： david A. JACKSON School of Physical Sciences Applied Optics Groups University of Kent UK

A conceptual coaxial Pitot tube （PT） has been developed using fiber optic sensors combined with actuators to monitor and maintain its correct operation under different environmental conditions. Experiments were performed showing that the dynamic and static tubes can be cleared of ice. It was also demonstrated that the dynamic tube could be cleared of dust and sand which was not the case for the static tube in the coaxial configuration. An approach was proposed to overcome this problem involving a conventional configuration where the static tube was operated independently orthogonal to the dynamic tube, and a second set of sensors and actuators was used. Sensors and associated actuators were developed for temperature and intensity for a linear PT. The aim of this work is to propose a solution for a problem that has caused the loss of the lives of many passengers and crew of aircraft. Resources were not available to test a full implementation of a PT incorporating the proposed modifications.

关键词： Pitot tube instrumentation FBG spectrometer pressure temperature optical intensity

Late Ordovician Mass Extinction: Earth, fire and ice

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National Science Review 2024年第1期11卷 51-65页

作者： david A.T.Harper Palaeoecosystems Group Department of Earth SciencesDurham University

The Late Ordovician Mass Extinction was the earliest of the ‘big' five extinction events and the earliest to affect the trajectory of metazoan life. Two phases have been identified near the start of the Hirnantian period and in the middle. It was a massive taxonomic extinction, a weak phylogenetic extinction and a relatively benign ecological extinction. A rapid cooling, triggering a major ice age that reduced the temperature of surface waters, prompted a drop in sea level of some 100 m and introduced toxic bottom waters onto the shelves. These symptoms of more fundamental planetary processes have been associated with a range of factors with an underlying driver identified as volcanicity. Volcanic eruptions, and other products, may have extended back in time to at least the Sandbian and early Katian, suggesting the extinctions were more protracted and influential than hitherto documented.

关键词： Ordovician LOME paleoecology palaeobiogeography biotas

Natural products and drug discovery

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National Science Review 2022年第11期9卷 37-57页

作者： david J.Newman NIH Special Volunteer

This review covers the recent history of a series of very important natural products and their derivatives that are currently in use or under evaluation in the areas of anti-infectives, important cancer treatments that include antibody drug conjugates, followed by a discussion of type 2 diabetes(T2DM) drugs and angiotensin converting enzyme inhibitors. The current structures of the agents are shown, though in the case of some peptides used in T2DM drugs the standard single leTher abbreviation for an amino acid is used.

关键词： artemisinin glycopeptides anthracyclines dolastatin diabetes 2 ACE inhibitors

Computationally designed protein activation

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National Science Review 2019年第4期6卷 609-610页

作者： david Baker Department of Biochemistry Institute for Protein Design University of Washington Howard Hughes Medical Institute

Time-resolved tools for activating proteins of interest in living systems can allow monitoring of the dynamics of biological processes such as signal transduction. Various approaches have been developed to engineer both constitutive and inducible protein activation (e.g. genetic fusion of light switchable proteins).Active-site decaging is another strategy,but the limited number of genetically encoded unnatural amino acids and associ-

关键词： pro Rosetta Computationally designed protein activation

Variable retention harvesting in Victoria’s Mountain Ash (Eucalyptus regnans) forests (southeastern Australia)

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Ecological Processes 2019年第1期8卷 12-20页

作者： david Lindenmayer david Blair Lachlan McBurney Fenner School of Environment and Society The Australian National UniversityCanberra ACT2601Australia

Variable retention harvesting is a silvicultural system that focuses on retaining key elements of stand structure at the time of logging and is increasingly being used *** describe the design and establishment of a variable retention harvesting experiment established in the Mountain Ash(Eucalyptus regnans)forests of the Central Highlands of Victoria,south-eastern *** experiment was instigated in 2003,and the work to date has shown that it has environmental benefits for certain groups of small mammals,birds,and vascular *** experiment has been integrated with an ongoing long-term monitoring program as well as other experiments such as those in post-fire salvage-logged ***,the results of various studies suggest that the potential value of variable retention harvesting extends beyond green-tree logging to post-fire salvage logging *** outline some of the challenges in,and new perspectives derived from,implementing and maintaining our *** included difficulties protecting islands from high-intensity post-harvest regeneration burns and threat of declining funding undermining ongoing project viability.A critically important perspective concerns the ecological and economic context in which variable retention harvesting is *** the particular case of Mountain Ash forests,assessments using formal IUCN criteria classify the ecosystem as being Critically Endangered under the Red Listed Ecosystem *** a result,Mountain Ash forests are at a high risk of ecosystem *** logging will increase that risk,making the basis for continued harvesting *** addition,economic analyses suggest that the value of natural assets,like water production,far outweigh the value of the wood products harvested from the Mountain Ash ecosystem,again leading to questions about the viability of ongoing *** therefore conclude that whilst variable retention harvesting has the potential to contrib

关键词： Alternative silvicultural systems Clear-cutting Biological legacies Forest biodiversity Forest economics,Retention islands

Portal vein embolization for induction of selective hepatic hypertrophy prior to major hepatectomy: rationale,techniques, outcomes and future directions

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Cancer Biology & Medicine 2016年第4期13卷 426-442页

作者： david Li david C.Madoff Department of Radiology Division of Interventional Radiology New York-Presbyterian Hospital Weill Cornell Medical Center

The ability to modulate the future liver remnant(FLR) is a key component of modern oncologic hepatobiliary surgery practice and has extended surgical candidacy for patients who may have been previously thought unable to survive liver resection. Multiple techniques have been developed to augment the FLR including portal vein embolization(PVE), associating liver partition and portal vein ligation(ALPPS), and the recently reported transhepatic liver venous deprivation(LVD). PVE is a well-established means to improve the safety of liver resection by redirecting blood flow to the FLR in an effort to selectively hypertrophy and ultimately improve functional reserve of the FLR. This article discusses the current practice of PVE with focus on summarizing the large number of published reports from which outcomes based practices have been developed. Both technical aspects of PVE including volumetry, approaches, and embolization agents; and clinical aspects of PVE including data supporting indications, and its role in conjunction with chemotherapy and transarterial embolization will be highlighted. PVE remains an important aspect of oncologic care; in large part due to the substantial foundation of information available demonstrating its clear clinical benefit for hepatic resection candidates with small anticipated FLRs.

关键词： Portal vein embolization future liver remnant hypertrophy liver regeneration liver cancer hepatocellular carcinoma liver metastases

Theoretical and Experimental Investigation of Driver Noncooperative-Game Steering Control Behavior

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IEEE/CAA Journal of Automatica Sinica 2021年第1期8卷 189-205页

作者： Xiaoxiang Na david Cole the Department of Engineering University of CambridgeCambridge CB21PZUK

This paper investigates two noncooperative-game strategies which may be used to represent a human driver's steering control behavior in response to vehicle automated steering *** first strategy,namely the Nash strategy is derived based on the assumption that a Nash equilibrium is reached in a noncooperative game of vehicle path-following control involving a driver and a vehicle automated steering *** second one,namely the Stackelberg strategy is derived based on the assumption that a Stackelberg equilibrium is reached in a similar context.A simulation study is performed to study the differences between the two proposed noncooperativegame *** experiment using a fixed-base driving simulator is carried out to measure six test drivers'steering behavior in response to vehicle automated steering *** Nash strategy is then fitted to measured driver steering wheel angles following a model identification *** weight parameters involved in the Nash strategy are *** is found that the proposed Nash strategy with the identified control weights is capable of representing the trend of measured driver steering behavior and vehicle lateral *** is also found that the proposed Nash strategy is superior to the classic driver steering control strategy which has widely been used for modeling driver steering control over the past.A discussion on improving automated steering control using the gained knowledge of driver noncooperative-game steering control behavior was made.

关键词： Driver experiment model identification noncooperative game steering control strategy vehicle

Use of tree species by three species of Magicicada(Hemiptera:Cicadidae)in an Appalachian forest

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Journal of Forestry Research 2023年第6期34卷 2051-2063页

作者： Cindy Perkovich david Ward Department of Biology and Toxicology Ashland UniversityAshlandOH 44805USA Department of Biological Sciences Kent State UniversityKentOH 44242USA

Periodical cicadas(Magicicada spp.)are endemic to deciduous forests in the eastern United *** successional forests,they must partition resources such as host trees to *** measured tree size,emergence holes,oviposition scar bundles,and chorusing center abundances of Magicicada species on 12 common tree species in a deciduous forest to understand host-tree *** predicted that the abundance of periodical cicadas and use of specific host-tree species would change depending on the Magicicada species and tree life *** considered the size of the tree(diameter at breast height)as a covariate to control for tree size and collected eggs for a greenhouse experiment to assess whether nymphs prefer to feed on Quercus rubra or Acer *** emergence holes were found below Quercus species than any other tree *** abundance of periodical cicadas on host trees used for chorusing centers varied depending on the Magicicada species,but were most abundant on Quercus *** scar bundles were also more frequent on *** nymphs were found on Quercus than Acer in the nymph preference *** periodical cicadas used Quercus hosts more than other tree species,their abundances on different host tree sizes and species differed *** cicada species may use specific host species and life stages as a way to partition resources and minimize competition among the Magicicada species during emergence years.

关键词： Ecological succession Habitat partitioning Periodical cicadas Successional forests