Built-in Advantage Research Articles

A UMAP-based clustering method for multi-scale damage analysis of laminates

In this study, a novel multi-scale damage model based on the parametric finite-volume direct averaging micromechanics theory (parametric FVDAM), extended finite element method (XFEM), and a clustering algorithm, is built, to describe the progressive damage evolution of laminates, where a uniform manifold approximation and projection (UMAP)-based clustering method is specially designed and incorporated with the FVDAM and XFEM for the first time. The subvolumes in the unit cell generated by FVDAM with similar mechanical responses were included in the same cluster using the UMAP-based clustering method. The semi-analytical framework of FVDAM allows the efficient generation of unit cells. The built-in advantage in the visualization of the proposed UMAP-based clustering method allows researchers in the field of mechanics to have a clear and intuitive understanding of the clustering results. The clustered unit cell is then conjugated to the XFEM, which allows the damage information to be transmitted between different scales. Three damage mechanisms of laminates under a three-dimensional (3D) stress state are considered, which include matrix damage, fiber breakage, and delamination. Furthermore, a shear nonlinear matrix Ds for a 3D element is derived and introduced in the model, which enables the description of the unique elastic nonlinear behavior of laminates. The model is implemented using UDMGINI and USDFLD subroutines in ABAQUS, which not only allows the calculation of the load–displacement curve, but also the simulation of clear and smooth crack propagation paths. To verify the effectiveness of the model, the experiments of [±60]2s and [90]8 notched glass-fiber/epoxy laminates under tension were performed by digital image correlation (DIC) monitoring, and the results compared were in good agreement with the simulations, thus proving the effectiveness of the proposed model. The code of the UMAP-based clustering method developed in this study can be downloaded from https://github.com/Danhui-Yang/MicroMechanicsUmapClustering.

Analysing a built-in advantage in asymmetric darts contests using causal machine learning

We analyse a sequential contest with two players in darts where one of the contestants enjoys a technical advantage. Using methods from the causal machine learning literature, we analyse the built-in advantage, which is the first-mover having potentially more but never less moves. Our empirical findings suggest that the first-mover has an 8.6% points higher probability to win the match induced by the technical advantage. Contestants with low performance measures and little experience have the highest built-in advantage. With regard to the fairness principle that contestants with equal abilities should have equal winning probabilities, this contest is ex-ante fair in the case of equal built-in advantages for both competitors and a randomized starting right. Nevertheless, the contest design produces unequal probabilities of winning for equally skilled contestants because of asymmetries in the built-in advantage associated with social pressure for contestants competing at home and away.

Identity Management Systems: Singular Identities and Multiple Moral Issues

The paper looks into some of the competing normative claims surrounding the development of Identity Management systems in general and Self-Sovereign Identity (SSI) systems in particular. It is argued that SSI developments should be assessed against the backdrop of IMs attempting to implement a global identity layer based on aggregated singular identities and reputation scores. It is also argued that this trend defines key ethical issues pertaining to the development of SSI systems. In order to explicate and evaluate these issues, the paper looks at the desirability of singular aggregated identities through the lens of moral-philosophical theories. It is argued that such an analysis strongly suggests moral desirability of a plural identities approach in SSIs that have built-in advantage for the implementation of practical separation of identities.

A Built-In Advantage

The Office of the Solicitor General wins the vast majority of Supreme Court cases in which it participates. Does it enjoy a built-in advantage, or does it win because it employs experienced litigators, enjoys resource advantages, or carries the executive’s sword? To answer these questions, we employ cutting edge matching methods. After matching OSG lawyers with nearly identical non-OSG lawyers in nearly identical cases, we find that OSG attorneys still are more likely to win their cases. We discuss possible reasons for this built-in advantage along with some practical implications of our findings.

Women Writers and the Edinburgh Enlightenment (review)

Reviewed by: Women Writers and the Edinburgh Enlightenment Evan Gottlieb (bio) Pam Perkins. Women Writers and the Edinburgh Enlightenment. Amsterdam: Rodopi, 2010. 320pp. US $86. ISBN 978-90-420-3137-1. This study of three Scottish women and the milieu in which they lived and wrote simultaneously deepens and partially revises our understanding of the place of female writers in Romantic-era Britain. In the early 1990s, studies such as Anne K. Mellor’s Romanticism and Gender (1993) demonstrated how representations of gender and sexuality were central to any critical understanding of “the Romantic ideology.” A few years later, critics began to ask a related question: if women’s issues had once been so central to the culture of British Romanticism, then what had happened to those female writers whose texts now had to be dug out of the archives to be reread? The collective answer, provided by critics such as Clifford Siskin, Catherine Gallagher, and Ina Ferris, was that women were pushed out of the market, and then out of the canon, by factors that included their own frequent (albeit overdetermined) choice to publish anonymously and the increasing professionalization of authorship that favoured their male competitors. As Pam Perkins ably demonstrates, this answer is productively complicated when we turn our critical attention to the successful careers enjoyed by many female Scottish authors throughout the Romantic era. Perkins focuses on three: Elizabeth Hamilton, Anne Grant, and Christian Isobel Johnstone. First, however, Perkins lays out the salient aspects of turn-of-the-nineteenth-century Edinburgh that facilitated their professional accomplishments. Whereas most Scots were keen to pro mote their erstwhile capital as “the Athens of the North,” Perkins notes that at least one anonymous novelist sneered that the remarkable literary productivity of its inhabitants also made it “the Birmingham of Literature” (18). Yet it was precisely this combination of Enlightened egalitarianism and a demystified, workaday approach to literary production that allowed women writers to prosper within the city’s literary culture. They also had a built-in advantage when it came to avoiding the increasingly dreaded label of “bluestocking,” benefitting from the general reputation of Scotswomen as “more modest and unassuming” than their English counterparts (37). Nevertheless, even north of the Tweed, Perkins asserts that a delicate balancing act was still required “for women who sought to establish a public, professional literary identity without overtly challenging their society’s ideas of femininity” (53). Each of the women whose careers Perkins considers found her own way to walk this socio-cultural tightrope. Although her first biographer made it appear that Hamilton more or less backed into her literary career, Perkins clearly demonstrates that her success was almost entirely [End Page 381] premeditated. Both of Hamilton’s initial novels, Translations of the Letters of a Hindoo Rajah (1796) and Memoirs of Modern Philosophers (1800), were pointed satires—“intellectually ambitious and often overtly polemical” (60)—which easily could have incurred the wrath of the male critical establishment. That they did not certainly owes something to their reactionary sensibilities, but it also speaks to Hamilton’s ability to convince readers that women could participate in contemporary political debates as an extension of, rather than an alternative to, their private lives. Although Perkins does not deny that most of Hamilton’s own ideas were hardly groundbreaking, she finds in her personal correspondence with some of the city’s most famous scientists further evidence of “Hamilton’s ability to blur the line between public intellectual work and private domesticity” (84). Even in Hamilton’s most characteristically Scottish novel, The Cottagers of Glenburnie (1808), Mrs MacClarty is laid low, not by any lack of domestic energy, but by “her moral and intellectual laziness” (127). It was precisely these kinds of Scottish subjects that Grant excelled at depicting. Yet Grant’s strategy for circumventing the barriers to success for literary women was in some respects the opposite of Hamilton’s: where the latter made clear that she was not to be mistaken for her characters, Grant cultivated a purposeful confusion between herself and her primarily Highland subjects. Letters from the Mountains (1806), which went through four editions in two years, details Grant’s experiences living near Inverness with her...

WebWatch

BioTechniquesVol. 50, No. 3 WebWatchOpen AccessWebWatchKevin AhernKevin Ahern*E-mail Address: ahernk@orst.eduSearch for more papers by this authorPublished Online:3 Apr 2018https://doi.org/10.2144/000113623AboutSectionsPDF/EPUB ToolsAdd to favoritesDownload CitationsTrack Citations ShareShare onFacebookTwitterLinkedInReddit A Ray of ScienceThousands of birds fell dead from the sky. A short distance away, 100,000 dead fish washed up on the shores of the Arkansas River. Over the New Year holiday, these sensational stories made headlines in every major newspaper across the country. Is the sky falling? Is the world coming apart at the seams? Fortunately, answers to these questions come not from the mainstream press, but from scientific investigators. Thankfully, there is a healthy, active science press on the job to give us the details. Front and center in any science reporting is ScienceRay, an online news site focused on chemistry, biology, environmental science, and physics, whose well-written articles are a voice of reason amidst the noise of a sensationalistic world. From a long set of essays on Galileo to the epidemic of bird, bat, and bee deaths, ScienceRay has it covered.[http://scienceray.com]Pro-LiteracyIt's hard not to admire the efforts of Action-Bioscience, a noncommercial enterprise whose goals are to promote bioscience literacy and education. The group's central aims include linking research developments to everyday life, encouraging students to pursue careers in the biosciences, and promoting global awareness. The opening page of the web site introduces visitors to biodiversity, the environment, genomics, biotechnology, evolution, and new frontiers in this discipline such as bioscience literacy and science/technology in the 21st century. Under each subheading, users will find hyperlinked articles clearly and carefully written by experts. Some stories are provocative (“For Sale: Iceland's Genetic History”), while others just make for great reading (“Mitochondria and Aging”). Whatever your level of interest in the biosciences, you'll find something to catch your attention at the ActionBioscience site.[www.actionbioscience.org]EnvironmethodologyEnvironmental science may encompass large physical spaces, but it also depends on analyses that extend down to the molecular level. Serving the needs of the discipline is the National Environmental Methods Index (NEMI), a web-based resource of microbiological, chemical, and biological methods for assaying relevant microbes, chemicals, and other vectors within the environment. Relevant techniques related to regulatory affairs, physical approaches (pH, conductivity, etc.), and toxicity are also there for the asking. Sponsored by the US Geological Survey and the EPA Office of Water, NEMI brims with downloadable, publicly available protocols that can be retrieved via a search function or by browsing. For analytical methods not in the public domain, NEMI returns relevant links, allowing users to quickly obtain needed information.[www.nemi.gov]Show and TellIn all of nature, there might not be a group of living organisms that elicits a stronger emotional response than the reptiles. From fright to delight, students will “eww” or “aww” whenever they see a snake, for example, onscreen. While for many, pictures are as close as they want to get to these organisms, for others, the images serve as introductions to creatures that can affect their career decisions or their choice of exotic pet. Mike Pingleton, who manages the Amphibian and Reptile Image site, clearly understands the impact reptiles can have; for the curious, his web site overflows with quality photographs of his subjects.[www.herp-pix.org]Eastern hognose snake (Heterodon platirhinos), North Carolina.© 2008 by Mike Pingleton.SciZineWhen communication is your oyster, you have a built-in advantage for self-promotion. Students at New York University's Science, Health, and Environmental Reporting program clearly know their way around the pressroom. Their online effort—called Scienceline (“the shortest distance between you and science”)—is a well researched, feature news site that looks more like the output of Wired or Discover magazine than of students in training. Written in comprehensible language, Scienceline superbly spotlights the student writers and editors. At press time, readers could choose between a wide-ranging collection of articles, including a controversial road through the Serengeti, curious monkeys, and the relationship between language and thinking.[www.scienceline.org]Open PathwaysCurrently in beta-stage testing, WikiPathways' “Pathways for the People” has a title that says it all. Pathways are the heart and soul of biochemistry and WikiPathways focuses on curating them for the scientific community in an open, public format. Unlike the pathways in your parents' biochemistry textbooks, WikiPathways intermingles traditional metabolic pathways with the vast number of cellular signaling pathways that have been elucidated. The site's design is outstanding, making information retrieval easy and straightforward. If you're wondering how many pathways involve the fos gene, analysis by the search engine gives the answer (120), which is organized by species. Pathway collections for entire species can be downloaded, and registration buys you the ability to upload new or edit existing pathways.[www.wikipathways.org]FiguresReferencesRelatedDetails Vol. 50, No. 3 Follow us on social media for the latest updates Metrics History Published online 3 April 2018 Published in print March 2011 Information© 2011 Author(s)PDF download

Effects of Ultraviolet Radiation on the Gram-Positive Marine Bacterium Microbacterium maritypicum

Although extensive information is available on the effect ultraviolet (UV) radiation has on Gram-negative marine bacteria, there is a scarcity of data concerning UV radiation and Gram-positive marine bacteria. The focus of this paper is on Microbacterium maritypicum, with the Gram-negative Vibrio natriegens being used as a standard of comparison. M. maritypicum exhibited growth over a NaCl range of 0-1000 mM: , with optimum growth occurring between 0 and 400 mM: NaCl. In contrast, V. natriegens grew over a NaCl span of 250-1000 mM: , with best growth being observed between 250 and 600 mM: NaCl. UV radiation experiments were done using the medium with 250 mM: NaCl. For solar (UV-A and B) radiation and log-phase cells, M. maritypicum was determined to be three times more resistant than V. natriegens. For germicidal (UV-C) radiation, the pattern of resistance of the log-phase cells to the lethal effects of the radiation was even more pronounced, with the Gram-positive bacterium being more than 12 to 13 times more resistant. Similar data to the solar and germicidal log-phase UV kill curves were obtained for stationary-phase cells of both organisms. Photoreactivation was observed for both types of cells exposed to UV-C but none for cells treated with UV-A and B. When log phase cells of M.maritypicum were grown at 0.0 and 0.6 M: NaCl and exposed to UV-C radiation, no difference in survivorship patterns was noted from that of 0.25 M: NaCl grown cells. Although this study has only focused on two marine bacteria, our results indicate that the Gram-positive M. maritypicum could have a built-in advantage for survival in some marine ecosystems.

Phase measurement of periodic optical pulses using temporal fractional Talbot effect

Proposed and demonstrated is a novel method for time-domain interferometry of optical pulse trains that does not need light pulse splitting. The interference is between time-shifted pulse-train replicas produced in a dispersive delay line via the temporal fractional Talbot effect. A built-in advantage of the method is its low sensitivity to environmental disturbance. In the experiment the method was used to demonstrate phase characterisation of periodic optical pulses.

Benzyladenine-preconditioning in Germinating Mungbean Seedlings Stimulates Axillary Buds in Cotyledonary Nodes Resulting in Multiple Shoot Regeneration.

Tissue culture and histological studies were done to ascertain the effects of benzyladenine (BA)-preconditioning on direct shoot regeneration from cotyledonary node explants of mungbean. The highest direct shoot regeneration (93.3%), double-sided shoot initiation (65.0%) and average number of shoots per explant (2.7 shoots) were obtained when Pag-asa 7 explants are excised from seedlings germinated in basal medium (BM) consisting of MS salts and B5 vitamins with 1.0mgl-1 BA, and subsequently cultured in fresh medium of the same composition. Histological inspection of sections from germinating seeds in BM and BM+1.0mgl-1 BA sampled at 1 to 4 days from germination revealed bigger and developmentally more advanced axillary shoots in BA-preconditioned seedlings, a built-in advantage which could attest to the improved regenerability in BA-treated seedling explants over the control (BM only). During shoot initiation from explants, two treatments namely doubling of the concentration BA to 2.0mgl-1 and the addition of a non-ionic surfactant, Pluronic F-68 did not further increase the responses, but gave results comparable with those obtained using BM+1.0mgl-1 BA alone. Conversely, a BA-thidiazuron (TDZ) combination (each at 1.0mgl-1) when added to BM significantly reduced shoot induction to only 48.3% possibly due to increased callusing at the nodes in 55% of the explants. The importance and applicability of the regeneration system in tissue culture and/or genetic manipulations of mungbean and other Asiatic Vigna species is discussed.

Successful Strategies for Inclusion at the Middle Level

Carmen Garcia smiled as she wel comed Robert to the Mariner team, showed him his seat, and introduced him to the three other seventh grade students at the table. Inside, however, shefelt a wave of uneasiness an self doubt. Robert was one of several special education stu dents being placed in regular classrooms. While Carmen's classes already included students with a wide range of she had no formal preparation for working with students with disabilities and knew little about modifying the learning environment to ensure their success. Her thoughts were filled with questions: Will I have to change the way I've always taught; how will I plan lessons that address the needs of special education students as well as the gifted; how will I ensure special students are accepted by the class; and what new challenges will these students bring regarding classroom management? Carmen is not alone. Many teachers experience similar thoughts and feelings when faced with the responsibility of teaching special students, especially when they feel unprepared to do so. Recipients of the 1994 Sallie Mae First Class Teacher Award claim that, more than anything else, additional preparation is need ed for working with students with special needs. One teacher states that, college prepared me for average and typical students—not for gifted students or students with special needs, (Sallie Mae Corporation, 1995, p. 11). In a research synthesis of 28 studies published from 1958 to 1995, Scruggs and Mastropieri (1996) conclud ed that while at least 50% of teachers felt mainstream ing/inclusion provided benefits for special students, only one third or fewer of these teachers believed ade quate time, skills, training, and resources had been pro vided to assist regular classroom teachers with special needs students. Even at the middle level, Scales (1992) reported that nearly two-thirds of teachers described their educational preparation for teaching diverse learn ers as inadequate or poor, disclosing a fundamental oversight in some preservice and inservice teacher edu cation programs. Fortunately, teachers of young adolescents may have a built-in advantage over teachers at either the ele mentary or high school level in relation to meeting the unique needs of special education students. Bradley and Fisher (1995) pointed out that as with special needs students, there is no typical middle school student, and because middle school students are by nature diverse, it is at this level that the inclusion process can be most successful (p. 13), especially when disabilities are per ceived as an extension of student diversity rather than classroom anomalies. Furthermore, Gritzmacher and Larkin (1993) suggested a congruence in the philoso phies of middle level and special educators regarding both the purpose and practice of educating students. These include a focus on needs of the individual, instruction by a team of teachers, attention to affective and cognitive objectives, and a climate of mutual collab oration. Middle schools, therefore, may be positioned to provide special education students with the neces sary frameworks and techniques to best meet their instructional needs as well as teachers who appreciate and champion middle level student diversity.

The semiconductor laser: a thirty-five-year perspective

Starting in 1962 with GaAs and the alloy GaAsP, the prototype III-V alloy the semiconductor laser developed slowly from a pulse-operated simple p-n junction to a continuously operated (300-K) double heterojunction in 1970. Then, in 1977, in another metamorphosis, it became a quantum-well (QW) device of reduced dimensionality (two dimensional) and improved density of states and performance. The fact that the semiconductor laser is based on an ideal form of "lamp", a p-n junction of potentially 100% quantum efficiency in conversion of electron-hole pairs to photons, gives it a built-in advantage over all other forms of lasers-all the indirectly excited lasers. Also, being a condensed system, it can be small-smaller than all other forms of lasers-and yet cover a great wavelength and power range, which continue to expand. Because of its third-layer form, a QW heterostructure (the product of more or less easily controlled epitaxial crystal growth) is amenable to modification by relatively simple processing operations such as impurity-induced layer disordering and now "wet" oxidation of Al-based layers, which makes possible a new generation of high-performance vertical-cavity surface emitting lasers (VCSELs). The VCSEL, with its oxide-defined high-Q flat cavity, reduced mode density, and approach now to instant "turn-on" (/spl mu/A currents), indicates that semiconductor lasers may not become much better than VCSELs, even if there is a change (not certain) in form from two to one to zero dimensional (and, if so, to problems in uniformity and reproducibility). If the technologies of the high-brightness transparent-substrate light emitting diode (LED) and the VCSEL converge much more, it is likely that the VCSEL-LED will become an addressable array (a display), a projection television, or a low- or high-power lamp, perhaps eventually on a large "diameter" Si platform. The study of the semiconductor laser, the first practical QW device, is not complete, nor is its development, which is certain to continue.

HDS/NA-6: an analog simulcast high definition television system

A high-definition system for North America (HDS/NA) embracing the simulcast mode of transmission for amplitude-modulated terrestrial and cable environments is described. The AM RF packaging techniques and the pertinent concerns for future tailoring of the system format for taboo channel utilization for broadcast-compatible terrestrial HDTV delivery in 6 MHz are highlighted. Without the constraint of direct NTSC compatibility with this system, carriers may be suppressed and standard NTSC sync headroom may be eliminated. Due to time expansion of all video components, there is a built-in advantage in multipath/echo performance, particularly beneficial for the cable short-echo scenario. The system is naturally expandable to permit an increase in resolution in the presence of additional channel bandwidth. This simulcast format is linked to a linear analog subband subsampling scheme used as a cornerstone for all HDS/NA analog transmission systems, including satellite (FSS and DBS) and augmentation terrestrial and cable formats. The generic HDS/NA subsampling scheme and the packaging of the components for a 6-MHz AM environment are described.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

The Barnhart Dictionary of Etymology (review)

1 84Reviews Robert K. Barnhart. The Barnhart Dictionary of Etymology. New York: H. W. Wilson, 1988. xxvii + 1284 pp. $59.00. The Middle English Dictionary is beginning to compare in scope with the OED, drawing on more than three million citations and stressing a continuing reading program. Any dictionary that uses these data is bound to be a better work. As Robert Barnhart planned his book as a truly new work, which might supersede Klein and Onions's Oxford dictionary, and as the MED was systematically and comprehensively used from the first, one's expectations are raised. When one learns that Clarence Barnhart and Kemp Malone were the inspiration for this five-year long project, and that Clarence's lexicographer son Robert was the editor, one can almost be assured of another accomplishment by the Barnhart family. Etymological dictionaries have enjoyed a long history. One of the earliest Western ones was Menage's Dictionnaire étymologique ou Origines de la langue françoise. There have been four major English ones in the twentieth century. Skeat's 1910 one is the most famous and, though dated and omissive, was reprinted in 1963. Partridge's went into a new American edition in 1977. The works that hold the present stage are Onions's book and Klein's, which was reprinted in 1 986. Both are scholarly, but are more than two decades old. Not only do they lack the newer words, but they have sometimes been superseded because the MED draws on many sources that were unavailable to the OED editors. Yet Onions is still an outstanding work, since it is based on the OED, however dated by the MED and Robert Burchfield's four-volume Supplement to the OED; a new edition is planned. As it is easier for one to write a new book than to revise an earlier edition, Robert Barnhart had a built-in advantage. We will briefly describe his preliminary and back matter, words, dates, and style, with comparisons chiefly to Onions and Klein. The rest of the review will be devoted to other major points and implications raised by his book. Reviews185 The prefatory and introductory matter are of the following length: Onions, 6 pages; Partridge and Barnhart, 8; Klein, 10; and Skeat, 26. Partridge and Onions have no bibliography. Klein has a 2-page one; Skeat, a 12-page one. Barnhart's totals 10 pages, of which 8 are a glossary of literary works cited in the entries. Also, unlike all competitors, Barnhart has a 5-page history of English by Einar Haugen, a leading scholar on borrowing , and it must be remembered that much of the information in an English etymological work must deal with borrowing . Barnhart includes Ralph L. Ward's 4-page essay on ProtoGermanic and Indo-European. While Onions and Klein do not have such an essay, Skeat's 10-page list of Indogermanic roots in some ways compensates for Ward's compact statement. Skeat incorporates those roots into the individual entries, as does Barnhart, who has no separate list of them. Additionally, Skeat has other valuable lists in an Appendix, which though sometimes wrong or omissive today, organize the data in revealing ways. He lists prefixes and suffixes (732-37), homonyms (737-48), doublets (748-51), Indogermanic roots (751-61), and "native" items and borrowings according to source (761-76). The list indicates intermediary sources, as for gypsum, which came from Arabic through Greek and then Latin, though he does not specify the intermediate forms. Barnhart provides this information in the entry for gypsum, as does Skeat, but Skeat's list cites two other ultimately Arabic borrowings that had this identical history. Thereby we know that gypsum was not unique and wonder whether other items may have followed this course. Though Skeat has no "Glossary of Language Names and Linguistic Terms" (Barnhart's is sixteen pages), overall his preliminary and back matter may still be the best in concept and in some details. Our second consideration is the words themselves. Barnhart includes thousands of recent items not included in any other etymological dictionary—ayatollah, FORTRAN, Mace, Telex, etc.—though the high-frequency AIDS and glasnost are missing. Special emphasis is placed...

Transfer Matrix Approach to Layered Systems

The stress and displacement distribution in a finite layered medium, statically loaded at the surface, is found by means of transfer matrices. Each layer is of infinite extent in the horizontal direction, of constant depth, and is considered to be linearly elastic, homogeneous and isotropic. The method developed has the built-in advantage of enforcing interface continuity conditions automatically. Its flexibility is shown by applying the technique to layered composites, in which case it predicts local as well as global behavior with equal ease.