Gender Representation on Journal Editorial Boards in the Mathematical Sciences

We study gender representation on the editorial boards of 435 journals in the mathematical sciences. Women are known to comprise approximately 15% of tenure-stream faculty positions in doctoral-granting mathematical sciences departments in the United States. Compared to this pool, the likely source of journal editorships, we find that 8.9% of the 13067 editorships in our study are held by women. We describe group variations within the editorships by identifying specific journals, subfields, publishers, and countries that significantly exceed or fall short of this average. To enable our study, we develop a semi-automated method for inferring gender that has an estimated accuracy of 97.5%. Our findings provide the first measure of gender distribution on editorial boards in the mathematical sciences, offer insights that suggest future studies in the mathematical sciences, and introduce new methods that enable large-scale studies of gender distribution in other fields.Comment: 21 pages, 10 figure

A primer of swarm equilibria

We study equilibrium configurations of swarming biological organisms subject to exogenous and pairwise endogenous forces. Beginning with a discrete dynamical model, we derive a variational description of the corresponding continuum population density. Equilibrium solutions are extrema of an energy functional, and satisfy a Fredholm integral equation. We find conditions for the extrema to be local minimizers, global minimizers, and minimizers with respect to infinitesimal Lagrangian displacements of mass. In one spatial dimension, for a variety of exogenous forces, endogenous forces, and domain configurations, we find exact analytical expressions for the equilibria. These agree closely with numerical simulations of the underlying discrete model.The exact solutions provide a sampling of the wide variety of equilibrium configurations possible within our general swarm modeling framework. The equilibria typically are compactly supported and may contain $\delta$-concentrations or jump discontinuities at the edge of the support. We apply our methods to a model of locust swarms, which are observed in nature to consist of a concentrated population on the ground separated from an airborne group. Our model can reproduce this configuration; quasi-two-dimensionality of the model plays a critical role.Comment: 38 pages, submitted to SIAM J. Appl. Dyn. Sy

Instabilities and Patterns in Coupled Reaction-Diffusion Layers

We study instabilities and pattern formation in reaction-diffusion layers that are diffusively coupled. For two-layer systems of identical two-component reactions, we analyze the stability of homogeneous steady states by exploiting the block symmetric structure of the linear problem. There are eight possible primary bifurcation scenarios, including a Turing-Turing bifurcation that involves two disparate length scales whose ratio may be tuned via the inter-layer coupling. For systems of $n$-component layers and non-identical layers, the linear problem's block form allows approximate decomposition into lower-dimensional linear problems if the coupling is sufficiently weak. As an example, we apply these results to a two-layer Brusselator system. The competing length scales engineered within the linear problem are readily apparent in numerical simulations of the full system. Selecting a $\sqrt{2}$:1 length scale ratio produces an unusual steady square pattern.Comment: 13 pages, 5 figures, accepted for publication in Phys. Rev.

PENGARUH BAURAN PEMASARAN JASA TERHADAP KEPUTUSAN PEMBELIAN KONSUMEN PADA KEDAI KOPI ANJIS BANDUNG

ABSTRAK Kedai Kopi Anjis Bandung merupakan usaha kuliner yang tengah berkembang terletak Jl Bengawan No. 34 Bandung. Berdasarkan hasil penelitian diketahui bahwa terdapat permasalahan sehubungan dengan keputusan pembelian konsumen yang diduga disebabkan oleh bauran pemasaran jasa yang dilakukan oleh Kedai Kopi Anjis Bandung seperti produk, promosi dan people yang belum dilaksanakan secara optimal. Metode penelitian yang digunakan adalah metode deskriptif analisis, teknik pengumpulan data dengan observasi non partisipan, wawancara terstruktur dan penyebaran angket kepada 30 responden yang dipilih secara acak. Analisa data yag digunakan adalah koefesien korelasi rank spearman. Hasil penelitian menunjukkan bahwa kondisi bauran pemasaran jasa Kedai Kopi Anjis Bandung secara umum dapat dikatakan dalam kondisi optimal dilihat dari product, price, place, promotion, people dan physical evidance, namun masih terdapat permasalahan di prosesnya. Adapun untuk kondisi keputusan pembelian konsumen secara umum dapat dikatakan sudah optimal dilihat dari pengenalan kebutuhan, evaluasi alternatif, dan perilaku pasca pembelian. Namun masih terdapat permasalahan dalam hal keputusan pembelian dan pencarian informasi. Adapun besaran pengaruh yang ditemukan bauran pemasaran jasa terhadap keputusan pembelian konsumen Kedai Kopi Anjis Bandung sebesar 72,5 %. Sisanya yaitu 27,5 % dipengaruhi oleh faktor lain tidak terindentifikasi, seperti jumlah wisatawan daerah bandung, cuaca, dan periode akhir bulan. Saran-saran yang dapat peneliti kemukakan antara lain Kedai Kopi Anjis Bandung sebaiknya melaksanakan bauran pemasaran jasa yang belum sepenuhnya dilakukan oleh Kedai Kopi Anjis Bandung yaitu produk, people dan promosi. Kedai Kopi Anjis Bandung sebaiknya memperhatikan hal-hal tentang keputusn pembelian yang belum sepenuhnya dilakukan oleh Kedai Kopi Anjis Bandung mengenai Menejemen Kedai Kopi Anjis Bandung sebaiknya melakukan bauran pemasaran jasa yang belum sepenuhnya optimal dilakukan oleh Kedai Kopi Anjis Bandung yaitu dari segi produk, people dan promosi sehingga Kedai Kopi Anjis Bandung diharapkan teliti dalam memenuhi apa yang di inginkan oleh konsumen agar bisa meningkatkan penjualan pada Kedai Kopi Anjis Bandung. Kata Kunci : Bauran Pemasaran Jasa, keputusan pembelian konsume

A model for rolling swarms of locusts

We construct an individual-based kinematic model of rolling migratory locust swarms. The model incorporates social interactions, gravity, wind, and the effect of the impenetrable boundary formed by the ground. We study the model using numerical simulations and tools from statistical mechanics, namely the notion of H-stability. For a free-space swarm (no wind and gravity), as the number of locusts increases, it approaches a crystalline lattice of fixed density if it is H-stable, and in contrast becomes ever more dense if it is catastrophic. Numerical simulations suggest that whether or not a swarm rolls depends on the statistical mechanical properties of the corresponding free-space swarm. For a swarm that is H-stable in free space, gravity causes the group to land and form a crystalline lattice. Wind, in turn, smears the swarm out along the ground until all individuals are stationary. In contrast, for a swarm that is catastrophic in free space, gravity causes the group to land and form a bubble-like shape. In the presence of wind, the swarm migrates with a rolling motion similar to natural locust swarms. The rolling structure is similar to that observed by biologists, and includes a takeoff zone, a landing zone, and a stationary zone where grounded locusts can rest and feed.Comment: 18 pages, 11 figure