Litmag 2015-16

Litmag is a student-run literary magazine published annually each spring through the English Department. Our purpose is to promote the creative work of students and staff and increase awareness of the ever-present literary talent on UMSL’s campus. We aim to produce a high quality journal that gives emerging writers and artists a venue to display their work and experience the world of professional publishing.https://irl.umsl.edu/litmag/1004/thumbnail.jp

The Agricultural Deities of Q’eqchi’ Mayas, Tzuultag’as: Agricultural Rituals as Historical Obligation and Avatar of the Cultural Reservoir in Rural Lanquín, Alta Verapaz, Guatemala

This study, based on fieldwork in rural Lanquín, Guatemala, discusses cultural continuity and the sense of historicity through agricultural rituals and worship of the agricultural deity Tzuultaq’as. The place, Lanquín, and the Q’eqchi’ Maya peasant farmers are situated within a two-fold tension and contradiction. Geographically remote in relation to the economic centers in Guatemala, and marginal in infrastructural development, while their cash crop harvests never fail to be effected by the fluctuations of the global market. From the eclectic stance merging both theories of cultural essentialism and constructivism, by juxtaposing the emblematic event of the anti-Monsanto Law movement in 2014 in Guatemala, and by the calendrical cycles of ritual events, routines, and ceremonials in rural Lanquín, the subsistence practices of milpa (corn field) cultivation emerge as a central theme for cultural survival and continuity. The aggregated clusters of ritual processions and the system of symbolism used manifest the Q’eqchi’ peasant thought and practice of sustainability and conservancy in their construction of a modern cultural identity that maintains congruency with the cultural essence of a nativist identity

Closed Terminologies and Temporal Reasoning in Description Logic for Concept and Plan Recognition

Description logics are knowledge representation formalisms in the tradition of frames and semantic networks, but with an emphasis on formal semantics. A terminology contains descriptions of concepts, such as UNIVERSITY, which are automatically classified ina taxonomy via subsumption inferences. Individuals such as COLUMBIA are described in terms of those concepts. This thesis enhances the scope and utility of description logics by exploiting new completeness assumptions during problem solving and by extending the expressiveness of descriptions. First, we introduce a predictive concept recognition methodology based on a new closed terminology assumption (CTA). The terminology is dynamically partitioned by modalities (necessary, optional, and impossible) with respect to individuals as they are specified. In our interactive configuration application, a user incrementally specifies an individual computer system and its components in collaboration with a configuration engine. Choices can be made in any order and at any level of abstraction. We distinguish between abstract and concrete concepts to formally define when an individual's description may be considered finished. We also exploit CTA, together with the terminology's subsumption-based organization, to efficiently track the types of systems and components consistent with current choices, infer additional constraints on current choices, and appropriately restrict future choices. Thus, we can help focus the efforts of both user and configuration engine. This work is implemented in the K-REP system. Second, we show that a new class of complex descriptions can be formed via constraint networks over standard descriptions. For example, we model plans as constraint networks whose nodes represent actions.Arcs represent qualitative and metric temporal constraints, plusco-reference constraints, between actions. By combining terminological reasoning with constraint satisfaction techniques, subsumption is extended to constraint networks, allowing automatic classification of a plan library. This work is implemented in the T-REX system, which integrates and builds upon an existing description logic system (K-REP or CLASSIC) and temporal reasoner (MATS). Finally, we combine the preceding, orthogonal results to conduct predictive recognition of constraint network concepts. As an example,this synthesis enables a new approach to deductive plan recognition,illustrated with travel plans. This work is also realized in T-REX

Self-complementary plane partitions by Proctor's minuscule method

A method of Proctor [European J. Combin. 5 (1984), no. 4, 331-350] realizes the set of arbitrary plane partitions in a box and the set of symmetric plane partitions as bases of linear representations of Lie groups. We extend this method by realizing transposition and complementation of plane partitions as natural linear transformations of the representations, thereby enumerating symmetric plane partitions, self-complementary plane partitions, and transpose-complement plane partitions in a new way

On Refined Enumerations of Totally Symmetric Self-Complementary Plane Partitions and Constant Term Identities

In this paper we give Pfaffian or determinant expressions, and constant term identities for the conjectures in the paper “Self-complementary totally symmetric plane partitions” (J. Combin. Theory Ser. A 42, 277–292) by Mills, Robbins and Rumsey. We also settle a weak version of Conjecture 6 in the paper, i.e., the number of shifted plane partitions invariant under a certain involution is equal to the number of alternating sign matrices invariant under the vertical flip

Monotone triangles and 312 pattern avoidance

International audienceWe demonstrate a natural bijection between a subclass of alternating sign matrices (ASMs) defined by a condition on the corresponding monotone triangle which we call the gapless condition and a subclass of totally symmetric self-complementary plane partitions defined by a similar condition on the corresponding fundamental domains or Magog triangles. We prove that, when restricted to permutations, this class of ASMs reduces to 312- avoiding permutations

Monotone triangles and 312 Pattern Avoidance

We demonstrate a natural bijection between a subclass of alternating sign matrices (ASMs) defined by a condition on the corresponding monotone triangle which we call the gapless condition and a subclass of totally symmetric self-complementary plane partitions defined by a similar condition on the corresponding fundamental domains or Magog triangles. We prove that, when restricted to permutations, this class of ASMs reduces to 312-avoiding permutations. This leads us to generalize pattern avoidance on permutations to a family of words associated to ASMs, which we call Gog words. We translate the gapless condition on monotone trangles into a pattern avoidance-like condition on Gog words associated. We estimate the number of gapless monotone triangles using a bijection with p-branchings

Alternierende Vorzeichenmatrizen und ebene Partitionen

Alternierende Vorzeichenmatrizen (ASMs) haben eine lange, immer noch aktuelle Tradition in der Kombinatorik und der Zusammenhang zu total symmetrischen, selbst-komplementären ebenen Partitionen (TSSCPPs), die von derselben Formel gezählt werden, ist immer noch ungeklärt. In der vorliegenden Arbeit betrachten wir ASMs und TSSCPPs in allgemeineren Kontexten, die vor allem durch Striker erforscht wurden. Zunächst beweisen wir einige Sätze über die Darstellung durch Ungleichungen, Facetten und Ecken des ASM-Polytops, das als die konvexe Hülle von n kreuz n ASMs definiert ist und beschreiben den Seitenverband mithilfe von Flussgittern. Danach widmen wir uns dem tetraedrischen Poset. Wir zeigen, dass die Ordnungsideale von Teilposets des tetraedrischen Posets mit bekannten kombinatorischen Objekten - darunter ASMs und TSSCPPs - in Bijektion stehen. Schließlich geben wir noch einen Einblick in pyramidale ebene Partitionen (PPPs). Wir betrachten zwei Klassen von PPPs und zählen Zeilen, Spalten sowie Hüllen und zeigen Bijektionen zu einem unerforschten Teilposet des tetraedrischen Posets sowie transponiert-komplementären, zyklisch symmetrischen ebenen Partitionen (TCSPP) und TSSCPPs.Alternating sign matrices (ASMs) have a long and recent tradition in combinatorics and they are counted by the same formula as totaly symmetric self-complementary plain partitions (TSSCPPs). Although the connection remains unclear and no explicit bijection is known. In this thesis we look at ASMs and TSSCPPs in larger contexts which are mainly based on the work of Striker. At first, we prove some theorems concerning the inequality description, facets and vertices of the ASM-Polytope which is defined as the convex hull of the n times n ASMs. We describe the face lattice by using flow grids. Then, we define the tetrahedral poset. We show that order ideals of subposets of the tetrahedral poset are in bijection with other combinatorial objects, among them ASMs and TSSCPPs. Finally we give an insight into pyramidal plane partitions (PPPs). We count rows, columns and hulls of two types of PPPs and show bijections to an unexplored subposet of the tetrahedral poset, transpose-complementary cyclically symmetric plane partitions (TCSPPs) and TSSCPPs