A Two Dimensional Vertically Integrated Moving Boundary Hydrodynamic Model in Curvilinear Coordinates.

A two dimensional, vertically averaged, hydrodynamic mathematical model on an adaptive boundary fitted grid is developed. This model addresses numerous drawbacks in the traditional finite difference models and incorporates such features as moving boundaries due to tidal incursion, and the ability to resolve irregular coastline geometries. A semi-implicit finite difference scheme is developed in order to overcome time step restrictions due to the gravity wave stability criterion. An eulerian-lagrangian formulation is used to solve the hydrodynamic equations on unsteady grid systems. The model is applied to study circulation features in Lake Pontchartrain (a medium sized physical system) and to the Bayou Chitigue channel pond system (a very small physical system), to demonstrate its ability to model systems of varying sizes and shapes

Extracting Features from Textual Data in Class Imbalance Problems

[EN] We address class imbalance problems. These are classification problems where the target variable is binary, and one class dominates over the other. A central objective in these problems is to identify features that yield models with high precision/recall values, the standard yardsticks for assessing such models. Our features are extracted from the textual data inherent in such problems. We use n-gram frequencies as features and introduce a discrepancy score that measures the efficacy of an n-gram in highlighting the minority class. The frequency counts of n-grams with the highest discrepancy scores are used as features to construct models with the desired metrics. According to the best practices followed by the services industry, many customer support tickets will get audited and tagged as contract-compliant whereas some will be tagged as over-delivered . Based on in-field data, we use a random forest classifier and perform a randomized grid search over the model hyperparameters. The model scoring is performed using an scoring function. Our objective is to minimize the follow-up costs by optimizing the recall score while maintaining a base-level precision score. The final optimized model achieves an acceptable recall score while staying above the target precision. We validate our feature selection method by comparing our model with one constructed using frequency counts of n-grams chosen randomly. We propose extensions of our feature extraction method to general classification (binary and multi-class) and regression problems. The discrepancy score is one measure of dissimilarity of distributions and other (more general) measures that we formulate could potentially yield more effective models.Aravamuthan, S.; Jogalekar, P.; Lee, J. (2022). Extracting Features from Textual Data in Class Imbalance Problems. Journal of Computer-Assisted Linguistic Research. 6:42-58. https://doi.org/10.4995/jclr.2022.182004258

ANA Webinars: Implementation of a conference-based virtual networking event

OBJECTIVE: To describe the design and implementation of a virtual network event at the American Neurological Association (ANA) annual meeting led by the Junior and Early Career Member (JECM) Committee. METHODS: We designed a one-hour virtual networking session featuring three 15-minute small group meetings preceded and followed by general remarks. Each small group session consisted of one senior mentor, a junior/early career faculty moderator, and three to four junior/early career mentees. All participants completed an exit survey to evaluate perceived benefit of this event. RESULTS: We recruited 103 mentees, 26 moderators, and 26 mentors for the event. Mentees were primarily at the resident training level or above (17% students). 56% of registered mentees, 100% of moderators and 96% of mentors attended the event for a total of 110 participants. Due to mentee attrition, each room contained 2-3 mentees. 90% of respondents felt the session met their goals very well or extremely well. Further, 99% felt this session was at least comparable to in-person networking at conferences and 60% felt this session was better than in-person networking. INTERPRETATION: Virtual networking sessions between junior and senior academic neurologists are feasible and are at least comparable to, if not better than, in-person conference networking. Future events should consider nuanced mechanisms of matching mentors and mentees, inclusion of ad hoc small groups to foster organic networking, and measures to safeguard against mentee attrition. Future studies should evaluate the long-term benefits of this event to determine if virtual networking should be utilized moving forward

Separable Hash Functions

We introduce a class of hash functions with the property that messages with the same hash are well separated in terms of their Hamming distance. We provide an example of such a function that uses cyclic codes and an elliptic curve group over a finite field. \smallskip A related problem is ensuring that the {\it consecutive distance} between messages with the same hash is as large as possible. We derive bounds on the c.d. separability factor of such hash functions

Development of a Social Robot as a Mediator for Intergenerational Gameplay & Development of a Canvas for the Conceptualisation of HRI Game Design

Intergenerational interaction between grandparents and grandchildren benefits both generations. The use of a social robot in mediating this interaction is a relatively unexplored area of research. Often Human-Robot Interaction (HRI) research uses the robot as a point of focus; this thesis puts the focus on the interaction between the generations, using a multi-stage study with a robot mediating the interaction in dyads of grandparents and grandchildren. The research questions guiding this thesis are: 1) How might a robot-mediated game be used to foster intergenerational gameplay? 2) What template can be created to conceptually describe HRI game systems? To answer the first question, the study design includes three stages: 1. Human mediator Stage (exploratory); 2. The Wizard-of-Oz (WoZ) Stage (where a researcher remotely controls the robot); 3. Fully/semi-autonomous Stage. A Tangram puzzle game was used to create an enjoyable, collaborative experience. Stage 1 of the study was conducted with four dyads of grandparents (52-74 years of age) and their grandchildren (7-9 years of age). The purpose of Stage 1 was to determine the following: 1. How do dyads of grandparent-grandchild perceive their collaboration in the Tangram game? 2. What role do the dyads envision for a social robot in the game? Results showed the dyads perceived high collaboration in the Tangram game, and saw the role of the robot as helping them by providing clues in the gameplay. The research team felt the game, in conjunction with the proposed setup, worked well for supporting collaboration and decided to use the same game with a similar setup for the next two stages. Although the design and development of the next stage were ready, the COVID-19 pandemic led to the suspension of in-person research. The second part of this thesis research focused on creating the Human-Robot Interaction Game Canvas (HRIGC), a novel way to conceptually model HRI game systems. A literature search of systematic ways to capture information, to assist in the design of the multi-stage study, yielded no appropriate tool, and prompted the creation of the HRIGC. The goal of the HRIGC is to help researchers think about, identify, and explore various aspects of designing an HRI game-based system. During the development process, the HRIGC was put through three case studies and two test runs: 1) Test run 1 with three researchers in HRI game design; 2) Test run 2 with four Human-Computer Interaction (HCI) researchers of different backgrounds. The case studies and test runs showed HRIGC to be a promising tool in articulating the key aspects of HRI game design in an intuitive manner. Formal validation of the canvas is necessary to confirm this tool

Cutaneous metastases from primary carcinoma larynx - A rare presentation

The incidence of secondary cutaneous deposits from squamous cell carcinoma larynx is very rare. We report a sixty nine year old male who was diagnosed with squamous cell carcinoma of larynx who was treated with radiotherapy and chemotherapy, presented with multiple grouped nodules over the neck  in a zosterifom pattern. Eventhough nodular, plaque-like, exuberant growth and sclerodermoid skin metastases have been described in laryngeal carcinoma, metastases to the skin in a grouped pattern is uncommon with only one case reported so far in the literture. The possible hypothesised cause of dermatomal metastatic distribution my be secondary to perineural lymphatic invasion and invasion of dorsal root gangliaby malignant cells.