2,528 research outputs found
Grid Graphs, Gorenstein Polytopes, and Domino Stackings
No full textWe examine domino tilings of rectangular boards, which are in natural bijection with perfect matchings of grid graphs. This leads to the study of their associated perfect matching polytopes, and we present some of their properties, in particular, when these polytopes are Gorenstein. We also introduce the notion of domino stackings and present some results and several open questions. Our techniques use results from graph theory, polyhedral geometry, and enumerative combinatorics.National Science Foundation (U.S.) (NSF (DMS-0810105)Deutsche Forschungsgemeinschaft (DFG Emmy Noether fellowship HA 4383/1
Representations of rational Cherednik algebras of G(m,r,n) in positive characteristic
No full textWe study lowest-weight irreducible representations of rational Cherednik algebras attached to the complex reflection groups G(m,r,n) in characteristic p. Our approach is mostly from the perspective of commutative algebra. By studying the kernel of the contravariant bilinear form on Verma modules, we obtain formulas for a Hilbert series of irreducible representations in a number of cases, and present conjectures in other cases. We observe that the form of the Hilbert series of irreducible representations and the generators of the kernel tend to be determined by the value of n modulo p and are related to special classes of subspace arrangements. Perhaps the most novel (conjectural) discovery from the commutative algebra perspective is that the generators of the kernel can be given the structure of a "matrix regular sequence'' in some instances, which we prove in some small cases.American Society for Engineering Education. National Defense Science and Engineering Graduate FellowshipUniversity of California, Berkeley (Miller Research Fellowship
A Finite Calculus Approach to Ehrhart Polynomials
No full textA rational polytope is the convex hull of a finite set of points in R[superscript d] with rational coordinates. Given a rational polytope P⊆R[superscript d], Ehrhart proved that, for t∈Z≥[subscript 0[, the function #(tP∩Z[superscript d]) agrees with a quasi-polynomial L[subscript P](t), called the Ehrhart quasi-polynomial. The Ehrhart quasi-polynomial can be regarded as a discrete version of the volume of a polytope. We use that analogy to derive a new proof of Ehrhart's theorem. This proof also allows us to quickly prove two other facts about Ehrhart quasi-polynomials: McMullen's theorem about the periodicity of the individual coefficients of the quasi-polynomial and the Ehrhart–Macdonald theorem on reciprocity
Free resolutions, combinatorics, and geometry
No full textThesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Mathematics, 2012.This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.Cataloged from student submitted PDF version of thesis.Includes bibliographical references (p. 71-72).Boij-Söderberg theory is the study of two cones: the first is the cone of graded Betti tables over a polynomial ring, and the second is the cone of cohomology tables of coherent sheaves over projective space. Each cone has a triangulation induced from a certain partial order. Our first result gives a module-theoretic interpretation of this poset structure. The study of the cone of cohomology tables over an arbitrary polarized projective variety is closely related to the existence of an Ulrich sheaf, and our second result shows that such sheaves exist on the class of Schubert degeneracy loci. Finally, we consider the problem of classifying the possible ranks of Betti numbers for modules over a regular local ring.by Steven V Sam.Ph.D
In Loving Memory Of Ola V. Alcorn
No full textFuneral program for Ola V. Alcorn, born November 18, 1930 and died March 21, 2002. The funeral was held March 26, 2002 at Lilly of the Vally Missionary Baptist Church, officiated by Pastor Steven R. Owens, Sr. The funeral arrangements were made through Sutton's Paradise Funeral Home and she was buried in Fort Sam Houston National Cemetery near San Antonio, Texas
Unified mathematical treatment of complex cascaded bipartite networks: The case of collections of journal papers
No full textIn this study, a mathematical treatment is proposed for analysis of entities and relations among entities in
complex networks consisting of cascaded bipartite networks. This treatment is applied to the case of
collections of journal papers. In this case, entities are distinguishable objects and concepts, such as papers,
references, paper authors, reference authors, paper journals, reference journals, institutions, terms, and term
definitions. Relations are associations between entity-types such as papers and the references they cite, or
paper authors and the papers they write. An entity-relationship model is introduced that explicitly shows
direct links between entity-types and possible useful indirect relations. From this a matrix formulation and
generalized matrix arithmetic are introduced that allow easy expression of relations between entities and
calculation of weights of indirect links and co-occurrence links. Occurrence matrices, equivalence
matrices, membership matrices and co-occurrence matrices are described. A dynamic model of growth
describes recursive relations in occurrence and co-occurrence matrices as papers are added to the paper
collection. Graph theoretic matrices are introduced to allow information flow studies of networks of papers
linked by their citations. Similarity calculations and similarity fusion are explained. Derivation of feature
vectors for pattern recognition techniques is presented. The relation of the proposed mathematical
treatment to seriation, clustering, multidimensional scaling, and visualization techniques is discussed. It is
shown that most existing bibliometric analysis techniques for dealing with collections of journal papers are
easily expressed in terms of the proposed mathematical treatment: co-citation analysis, bibliographic
coupling analysis, author co-citation analysis, journal co-citation analysis, Braam-Moed-vanRaan (BMV)
co-citation/co-word analysis, latent semantic analysis, hubs and authorities, and multidimensional scaling.
This report discusses an extensive software toolkit that was developed for this research for analyzing and
visualizing entities and links in a collection of journal papers. Additionally, an extensive case study is
presented, analyzing and visualizing 60 years of anthrax research through a collection of journal papers.
When dealing with complex networks that consist of cascaded bipartite networks, the treatment presented
here provides a general mathematical framework for all aspects of analysis of static network structure and
network dynamic growth. As such, it provides a basic paradigm for thinking about and modeling such
networks: computing direct and indirect links, expressing and analyzing statistical distributions of network
characteristics, describing network growth, deriving feature vectors, clustering, and visualizing network
structure and growth
Corolla size and temporal displacement of flowering times among sympatric diploid and tetraploid highbush blueberry (Vaccinium corymbosum)
No full textPolyploidy (whole-genome duplication) is common in vascular plants, but the modes of establishment and persistence, as well as the ecological consequences, of polyploidy remain vague. Highbush blueberry (Vaccinium corymbosum L.) is an ecologically and economically important understory shrub with an unclear species definition, coexisting in sympatric populations of diploid and tetraploid cytotypes. This study analyzes differences in bloom time between sympatric diploid and tetraploid V. corymbosum in natural populations, testing the potential for these cytotypes to interbreed and contributing to the formation and continuity of ploidy-level diversification within this species. Ploidal level was confirmed through DNA flow cytometry of sympatric plants from two populations in New Jersey, USA. Flower bloom date and corolla size were recorded over a three-year period. Diploid corollas were 32% smaller than tetraploid corollas, making them easily identifiable in the field. Ploidy accounted for 55-69% of the variation in bloom date, with diploids flowering about one week before tetraploids, and the remaining variation distributed among plants, among branches, and within branches. Notwithstanding these differences, there was modest overlap in flowering time between cytotypes, suggesting that cross-pollination is possible. This contributes evidence to the most current species definition of V. corymbosum as a single (mixed ploidy) species.Poster's Graduate Student Thesis Publication.Peer reviewed
The ‘Galilean Style in Science’ and the Inconsistency of Linguistic Theorising
No full textChomsky’s principle of epistemological tolerance says that in theoretical linguistics contradictions between the data and the hypotheses may be temporarily tolerated in order to protect the explanatory power of the theory. The paper raises the following problem: What kinds of contradictions may be tolerated between the data and the hypotheses in theoretical linguistics? First a model of paraconsistent logic is introduced which differentiates between week and strong contradiction. As a second step, a case study is carried out which exemplifies that the principle of epistemological tolerance may be interpreted as the tolerance of week contradiction. The third step of the argumentation focuses on another case study which exemplifies that the principle of epistemological tolerance must not be interpreted as the tolerance of strong contradiction. The reason for the latter insight is the unreliability and the uncertainty of introspective data. From this finding the author draws the conclusion that it is the integration of different data types that may lead to the improvement of current theoretical linguistics and that the integration of different data types requires a novel methodology which, for the time being, is not available
The Steven F. Lawson Papers: A Collection Guide
No full textSteven F. Lawson is professor emeritus of history at Rutgers University. He holds a B.A. in history from City College of New York (1966), and an M.A. and a Ph.D. in American history from Columbia University (1967, 1974). Lawson began his teaching career at the University of South Florida, St. Petersburg in 1972. He moved to the USF, Tampa campus in 1978, but continued to teach courses on the St. Pete Campus through the mid-1980s. He served as chair of the USF History Department from 1983 to 1986. From 1992 to 1998 he was head of the History Department at the University of North Carolina-Greensboro, and professor of history at Rutgers from 1999 to 2009. He has written extensively about civil rights, particularly about voting rights for African Americans in the post-World War II period, and is the author of eight books, thirty journal articles, book chapters, and essays. His books include Black Ballots: Voting Rights in the South, 1944-1969 (Columbia University Press, 1976), which won the Phi Alpha Theta Award for Best First Book in 1977; In Pursuit of Power: Southern Blacks and Electoral Politics, 1965-1982 (Columbia University Press, 1985), a CHOICE Outstanding Book for 1986; Running for Freedom: Black Politics in America since 1941 (Wiley-Blackwell, 2013), 4th edition; and (with Nancy A. Hewitt) Exploring American Histories: A Survey with Sources (Bedford-Macmillan, 2018), 3rd edition.
Lawson has been a consultant for the National Parks Service, the National Civil Rights Museum, and the award-winning documentary film series Eyes on the Prize. He served as managing editor and then associate editor of Tampa Bay History from 1979 to 1992 and as co-director of the North Carolina Politics Project at the University of North Carolina-Chapel Hill from 1995 to 1996. He has also been an expert witness in several court cases, including Warren v. Krivanek in 1985, Concerned Citizens of Hardee County Florida v. County Commissioners of Hardee County in 1989, U.S. v. Georgia/ Brooks v. Miller in 1996, and United States of America vs. The State of North Carolina; The North Carolina State Board of Elections; and Kim W. Strach in 2013
Perception of death by students of general nursing
No full textAutor: Steven Hastrdlo Instituce: Ústav nelékařských studií LF UK v Hradci Králové Název práce: Vnímání smrti u studentů oboru všeobecná sestra Vedoucí práce: doc. PhDr. Jana Kutnohorská, CSc. Počet stran: 129 Počet příloh: 8 Rok obhajoby: 2021 Klíčová slova: smrt, umírání, paliativní péče, eutanazie, vnímání smrti Bakalářská práce se zabývá vnímáním smrti u studentů oboru všeobecná sestra. Práce se skládá z dvou částí. První část se zabývá teoretickými poznatky týkající se smrti a umírání, komunikací s umírajícím, péčí o umírajícího i péčí o mrtvé tělo. Dále je zde zmíněna problematika eutanazie, asistované sebevraždy a dříve vysloveného přání. V praktické část jsou analyzovány výsledky kvantitativního výzkumu, týkajícího se vnímání smrti u studentů oboru všeobecná sestra. Výzkum byl uskutečněn formou anonymního dotazníku mezi studenty 1. a 3. ročníku oboru všeobecná sestra. Stanoveny byly 3 dílčí cíle, které byly splněny. Zajímavý je výstup, že respondenti se strachem ze smrti převažoval pouze v 1. ročníku, ve 3. ročníku tvořili menšinu. Výsledky výzkumného šetření je možno využít v pedagogické praxi, v paliativní péči a pro další výzkum.Name and surname of the author: Steven Hastrdlo Institution: Charles University Faculty of Medicine in Hradec Králové, Department of Non-medical Studies Title: Perception of death by General Nursing students Supervisor: doc. PhDr. Jana Kutnohorská, CSc. Number of pages: 129 Number of attachements: 8 Year of defense: 2021 Keywords: death, dying, palliative care, euthanasia, perception of death This thesis deals with perception of death by General Nursing students. The thesis consists of two parts. The first part deals with theoretical knowledge about death and dying, comunication with the dying, care of the dying and care of the dead body. There are also coverd issues of euthanasia, assisted suicide and living will. Prakctical part analyzes the outcome of a quantitative research, concerning the perception of death by General Nursing students. The research was carried out using a questionnaire survey within students in 1st and 3rd year of General Nursing studies. There were set three goals, all of wich were achieved. Interesting outcome was, that respondents with fear of death prevailed only in 1st year of the studies, in 3rd year they represented a minority. Outcome of the research can be used in pedagogy, paliative care and for further research.Department of Social MedicineÚstav sociálního lékařstvíLékařská fakulta v Hradci KrálovéFaculty of Medicine in Hradec Králov
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