The use of animated agents in e‐learning environments: an exploratory, interpretive case study

There is increasing interest in the use of animated agents in e‐learning environments. However, empirical investigations of their use in online education are limited. Our aim is to provide an empirically based framework for the development and evaluation of animated agents in e‐learning environments. Findings suggest a number of challenges, including the multiple dialogue models that animated agents will need to accommodate, the diverse range of roles that pedagogical animated agents can usefully support, the dichotomous relationship that emerges between these roles and that of the lecturer, and student perception of the degree of autonomy that can be afforded to animated agents

UPC++ v1.0 Specification, Revision 2020.3.0

UPC++ is a C++11 library providing classes and functions that support Partitioned Global Address Space (PGAS) programming. The key communication facilities in UPC++ are one-sided Remote Memory Access (RMA) and Remote Procedure Call (RPC). All communication operations are syntactically explicit and default to non-blocking; asynchrony is managed through the use of futures, promises and continuation callbacks, enabling the programmer to construct a graph of operations to execute asynchronously as high-latency dependencies are satisfied. A global pointer abstraction provides system-wide addressability of shared memory, including host and accelerator memories. The parallelism model is primarily process-based, but the interface is thread-safe and designed to allow efficient and expressive use in multi-threaded applications. The interface is designed for extreme scalability throughout, and deliberately avoids design features that could inhibit scalability

Array of sensors: A spatiotemporal-state-space model for target trajectory tracking

In this paper, with the objective of tracking the trajectory of multiple mobile targets, a novel spatiotemporal-state-space model is introduced for an array of sensors distributed in space. Under the wideband assumption, the proposed model incorporates the array geometry in conjunction with crucial target parameters namely (i) ranges, (ii) directions, (iii) velocities and (iv) associated Doppler effects. Computer simulation studies show some representative examples where the proposed model is utilised to track the locations of sources in space with a very high accuracy

On the probability of finding marked connected components using quantum walks

Finding a marked vertex in a graph can be a complicated task when using quantum walks. Recent results show that for two or more adjacent marked vertices search by quantum walk with Grover's coin may have no speed-up over classical exhaustive search. In this paper, we analyze the probability of finding a marked vertex for a set of connected components of marked vertices. We prove two upper bounds on the probability of finding a marked vertex and sketch further research directions.Comment: 13 pages. To appear at Lobachevskii Journal of Mathematic

A new species of the genus Gomphomastax Brunner von Wattenwyl (Orthoptera: Eumastacidae: Gomphomastacinae) from Indian Kashmir

A new species, Gomphomastax nigrovittata Usmani, from Kashmir is described and illustrated. In addition to conventional morphological characters, genitalic structures are also studied. A key to known species of Gomphomastax from Indian Kashmir is given

Iron-mediated Preparation of Vinylcyclopropanes. Scope, Mechanism, and Applications

The addition of stabilized carbon nucleophiles to tricarbonyl(1-methoxycarbonylpentadienyl)iron(1+) cation (1a) proceeds via attack at C2 on the face of the ligand opposite the Fe(CO)3 group to generate tricarbonyl(pentenediyl)iron complexes 2. Oxidation of complexes 2 affords vinylcyclopropanecarboxylates in good yield. In general, the relative stereochemistry about the cyclopropane ring reflects reductive elimination with retention of configuration. In cases where the C2 substituent is bulky (i.e., 2b) the major cyclopropane product 9b represents ring closure with inversion at C3. A mechanism involving π−σ−π rearrangement of the initially oxidized (pentenediyl)iron species is proposed to account for these results. Experiments which probe the stereochemistry of deuterium labeling in the vinyl group of the vinylcyclopropanecarboxylate products were carried out, and these results are consistent with the proposed mechanism. This methodology for the preparation of vinylcyclopropanecarboxylates was applied to the synthesis of 2-(2‘-carboxycyclopropyl)glycines (+)-22 and (−)-23 and the cyclopropane triester (−)-26

Comment on "Fermionic entanglement ambiguity in noninertial frames"

In this comment we show that the ambiguity of entropic quantities calculated in Physical Review A 83, 062323 (2011) for fermionic fields in the context of Unruh effect is not related to the properties of anticommuting fields, as claimed in Physical Review A 83, 062323 (2011), but rather to wrong mathematical manipulations with them and not taking into account a fundamental superselection rule of quantum field theory.Comment: To appear in Physical Review A. Some of the problems discussed in this comment can also be found in other previously published papers studying the Unruh effect for fermions (in the context of quantum information theory). An extended version of the comment can be found here http://arxiv.org/abs/1108.555