On the Combinatorics of Schubert Calculus

NS

Assessing effectiveness of Minecraft-based interventions to improve interpersonal skills of youth with Autism Spectrum Disorder

Teenagers with Autism Spectrum Disorder (ASD) experience bullying and social exclusion more than typically developing teens which can lead to feelings of depression and anxiety. These consequences are related to significant impairments in social reciprocity, a core feature of ASD. Face-to-face social skills training (SST) like the Program for the Education and Enrichment of Relational Skills) for Adolescents (PEERS) has been found to increase social skills for youth with ASD. Can these SSTs be brought online? Minecraft, a versatile online platform and a shared language among teenagers across the globe has been used therapeutically to increase social skills (i.e. social reciprocity, social problem solving, and social collaboration) while minimizing the negative sense of self heightened in face to face experiences. Using the pre-post tests for social skills and scales of depression, anxiety, and loneliness, this study aims to examine the effectiveness of adapting this program in the Minecraft-based environment with 30 teenagers with high functioning ASD (ages 13-18)

Electrochemical treatment of industrial sulfidic spent caustic streams for sulfide removal and caustic recovery

Alkaline spent caustic streams (SCS) produced in the petrochemical and chemical manufacturing industry, contain high concentrations of reactive sulfide (HS-) and caustic soda (NaOH). Common treatment methods entail high operational costs while not recovering the possible resources that SCS contain. Here we studied the electrochemical treatment of SCS from a chemical manufacturing industry in an electrolysis cell, aiming at anodic HS- removal and cathodic NaOH, devoid of sulfide, recovery. Using a synthetic SCS we first evaluated the HS- oxidation product distribution over time, as well as the HS- removal and the NaOH recovery, as a function of current density. In a second step, we investigated the operational aspects of such treatment for the industrial SCS, under 300 A m(-2) fixed current density. In an electrolysis cell receiving 205 +/- 60 g S L-1 d(-1) HS- over 20 days of continuous operation, HS- was removed with a 38.0 +/- 7.7 % removal and similar to 80 % coulombic efficiency, with a concomitant recovery of a similar to 12 wt.% NaOH solution. The low cell voltage obtained (1.75 +/- 0.12 V), resulted in low energy requirements of 3.7 +/- 0.6 kW h kg(-1) S and 6.3 +/- 0.4 kW h kg(-1) NaOH and suggests techno-economic viability of this process

Optimal multiple FSO transceiver configuration for using on High-altitude platforms

Free-space optical (FSO) communication requires light of sight (LoS) between the transmitter and the receiver. For long-distance communication, many research projects have been conducted towards using a network composed of high-altitude platforms (HAPs) flying at an elevation of 20 km to carry intermediate FSO transceivers that forward data between ground stations. The clear environment at high elevations prevents terrestrial obstacles from cutting the LoS between the transceivers. An FSO transceiver on a HAP can communicate with ground stations within a small area owing to its limited beam size. We suggest using multiple FSO transceivers on a HAP to extend its ground coverage. However, the use of too many FSO transceivers may quickly exhaust the onboard energy of the HAP. As a result, HAP must be lowered to recharge frequently. In this study, we first propose a configuration of multiple FSO transceivers to widen the ground coverage of a HAP. We then propose a set of closed-form expressions to calculate the extended coverage. Finally, to implement a HAP network using multiple FSO transceivers, we seek the optimal configuration of multiple FSO transceivers that minimizes the total cost of the HAP network, including amortization, energy, and maintenance costs. The simulation results show that the proposed multiple FSO transceiver configuration clearly increases the ground coverage of a HAP and significantly reduces the cost of the HAP network.Comment: Submitted to an IEEE journa

Beam Size Optimization for High-Altitude Platforms to Ground Links in FSO Communications

Free-space optical (FSO) communication has been used in practice mainly for short-distance transmission because it requires light of sight (LoS) between the transmitter and receiver. For long-distance communication, to avoid terrestrial obstacles, high-altitude platforms (HAPs) flying at stratosphere are used to carry intermediate FSO transceivers which relay data through several hops from the source to the destination stations. A HAP can communicate with a large ground area if its FSO transceiver projects a wide beam onto the ground. However, an excessively large beam makes the FSO transceiver consume a lot of energy. This study investigates the problem of finding individual optimal beam sizes for FSO transceivers on HAPs so that the total cost of the HAP network, including the amortization, energy, and maintenance costs, is minimized. An optimization algorithm was proposed and implemented. The simulation results show the network designed by the algorithm achieves a nearly optimal number of HAPs, leading to a low network cost