We analyze the structure of reduced expressions in the Coxeter groups An, Bn and Dn. Several special classes of elements are singled out for their connections with symmetric functions or the theory of P -partitions. Membership in these special classes is characterized in a variety of ways, including forbidden patterns, forbidden subwords, and by the form of canonically chosen reduced words.

We introduce and study a class of simplicial complexes, the orphan complexes, associated to simple graphs whose family of (open or closed) vertex-neighborhoods are anti-Sperner. Under suitable restrictions, we show that orphan complexes of such graphs are always shellable and provide a characterization of graphs in terms of induced forbidden subgraphs contained in this restricted subfamily.

In this paper we demonstrate that several theorems from [1] and [3] do not hold as they are stated. These are the theorems regarding forbidden subposet characterizations of certain classes of coverincomparability graphs. In this paper we correct a mistake in the main theorem of [1], reformulate the corresponding statements and present corrected proofs. We further characterize posets whose cover...

We are developing a symmetric gain optoelectronic mixer for chirped-AM laser detection and ranging systems (LADAR) operating in the “eye-safe” 1.55 m wavelength range. Signal processing of a chirped-AM LADAR system is simplified if the photodetector in the receiver is used as an optoelectronic mixer (OEM). Adding gain to the optoelectronic mixer allows the following transimpedance amplifier’s ...

The recent demonstration of an all-optical, stored program, digital computer by our group focused on high speed optoelectronic design. It was made possible by a new digital design method known as time-of-flight design. A rudimentary, but general purpose, proof of principle computer was built, which is all-optical in the sense that all signals connecting logic gates and all memory are optical in...

Development and design of optical communication and optoelectronic systems is now necessary for the engineers in electronics and microelectronics [1]. While such design is mainly based on the physical understanding of the optics and optoelectronic phenomena, it cannot be efficiently achieved without using the design and optimization tools. Computer Aided Design (CAD) tools are now widely used i...

We conducted a reliability comparison study to determine the intrarater and inter-rater reliability and the limits of agreement of the volume estimated by circumferential measurements using the frustum sign method and the disk model method, by water displacement volumetry, and by infrared optoelectronic volumetry in the assessment of upper limb lymphedema. Thirty women with lymphedema following...

The formation of semiconductor heterojunctions and their high-density integration are foundations of modern electronics and optoelectronics. To enable two-dimensional crystalline semiconductors as building blocks in next-generation electronics, developing methods to deterministically form lateral heterojunctions is crucial. Here we demonstrate an approach for the formation of lithographically p...

Creating high aspect ratio (AR) nanostructures by top-down fabrication without surface damage remains challenging for III-V semiconductors. Here, we demonstrate uniform, array-based InP nanostructures with lateral dimensions as small as sub-20 nm and AR > 35 using inverse metal-assisted chemical etching (I-MacEtch) in hydrogen peroxide (H2O2) and sulfuric acid (H2SO4), a purely solution-based y...

Organic materials are used in novel optoelectronic devices because of the ease and high compatibility of their fabrication processes. Here, we demonstrate a low-driving-voltage cathodic-controlled organic upconverter with a mapping application that converts near-infrared images to produce images of visible blood vessels. The proposed upconverter has a multilayer structure consisting of a photos...