pwc-archive/papers-with-abstracts huggingface dataset:
Obstacles to Redistribution Through Markets and One Solution
Authors: Roy Allen, John Rehbeck
Date: 2021-11-18 00:00:00

Dworczak et al. (2021) study when certain market structures are optimal in the presence of heterogeneous preferences. A key assumption is that the social planner knows the joint distribution of the value of the good and marginal value of money. This paper studies whether relevant features of this distribution are identified from choice data. We show that the features of the distribution needed to characterize optimal market structure cannot be identified when demand is known for all prices. While this is a negative result, we show that the distribution of good value and marginal utility of money is fully identified when there is an observed measure of quality that varies. Thus, while Dworczak et al. (2021) abstract from quality, we show how including quality is crucial for potential applications.
Comparative Study of Speech Analysis Methods to Predict Parkinson's Disease
Authors: Adedolapo Aishat Toye, Suryaprakash Kompalli
Date: 2021-11-15 00:00:00

One of the symptoms observed in the early stages of Parkinson's Disease (PD) is speech impairment. Speech disorders can be used to detect this disease before it degenerates. This work analyzes speech features and machine learning approaches to predict PD. Acoustic features such as shimmer and jitter variants, and Mel Frequency Cepstral Coefficients (MFCC) are extracted from speech signals. We use two datasets in this work: the MDVR-KCL and the Italian Parkinson's Voice and Speech database. To separate PD and non-PD speech signals, seven classification models were implemented: K-Nearest Neighbor, Decision Trees, Support Vector Machines, Naive Bayes, Logistic Regression, Gradient Boosting, Random Forests. Three feature sets were used for each of the models: (a) Acoustic features only, (b) All the acoustic features and MFCC, (c) Selected subset of features from acoustic features and MFCC. Using all the acoustic features and MFCC, together with SVM produced the highest performance with an accuracy of 98% and F1-Score of 99%. When compared with prior art, this shows a better performance. Our code and related documentation is available in a public domain repository.
Varifocal Multiview Images: Capturing and Visual Tasks
Authors: Kejun Wu, Qiong Liu, Guoan Li, Gangyi Jiang, You Yang
Date: 2021-11-19 00:00:00

Multiview images have flexible field of view (FoV) but inflexible depth of field (DoF). To overcome the limitation of multiview images on visual tasks, in this paper, we present varifocal multiview (VFMV) images with flexible DoF. VFMV images are captured by focusing a scene on distinct depths by varying focal planes, and each view only focused on one single plane.Therefore, VFMV images contain more information in focal dimension than multiview images, and can provide a rich representation for 3D scene by considering both FoV and DoF. The characteristics of VFMV images are useful for visual tasks to achieve high quality scene representation. Two experiments are conducted to validate the advantages of VFMV images in 4D light field feature detection and 3D reconstruction. Experiment results show that VFMV images can detect more light field features and achieve higher reconstruction quality due to informative focus cues. This work demonstrates that VFMV images have definite advantages over multiview images in visual tasks.
Optimization of Quantized Phase Shifts for Reconfigurable Smart Surfaces Assisted Communications
Authors: Maximiliano Rivera, Mohammad Chegini, Wael Jaafar, Safwan Alfattani, Halim Yanikomeroglu
Date: 2021-11-19 00:00:00
Tasks: Quantization

Reconfigurable Smart Surface (RSS) is assumed to be a key enabler for future wireless communication systems due to its ability to control the wireless propagation environment and, thus, enhance communications quality. Although optimal and continuous phase-shift configuration can be analytically obtained, practical RSS systems are prone to both channel estimation errors, discrete control, and curse of dimensionality. This leads to relaying on a finite number of phase-shift configurations that is expected to degrade the system's performances. In this paper, we tackle the problem of quantized RSS phase-shift configuration, aiming to maximize the data rate of an orthogonal frequency division multiplexing (OFDM) point-to-point RSS-assisted communication. Due to the complexity of optimally solving the formulated problem, we propose here a sub-optimal greedy algorithm to solve it. Simulation results illustrate the performance superiority of the proposed algorithm compared to baseline approaches. Finally, the impact of several parameters ,e.g., quantization resolution and RSS placement, is investigated.
Integrated Sensing and Communications for V2I Networks: Dynamic Predictive Beamforming for Extended Vehicle Targets
Authors: Zhen Du, Fan Liu, Weijie Yuan, Christos Masouros, Zenghui Zhang, Shuqiang Xia, Giuseppe Caire
Date: 2021-11-19 00:00:00
Tasks: Integrated sensing and communication, ISAC

We investigate sensing-assisted predictive beamforming schemes for vehicle-to-infrastructure (V2I) communication by exploiting the integrated sensing and communication (ISAC) functionalities at the roadside unit (RSU). The RSU deploys a massive multi-input-multi-output (mMIMO) array and operates at millimeter wave (mmWave) frequencies. The pencil-sharp mMIMO beams and fine range resolution achieved at mmWave, implicates that the point target assumption is impractical in such V2I networks, as the volume and shape of the vehicles become essential for beamforming. Simply pointing a beam to the vehicle may result in the communication receiver (CR) never lying in the beam, even when the vehicle's trajectory is accurately tracked. To tackle this problem, we consider the extended vehicle target with two novel beam tracking schemes. For the first scheme, the beamwidth is adjusted in real-time to cover the entire vehicle, followed by an extended Kalman filtering (EKF) algorithm to predict and track the position of CR according to the resolved high-resolution scatterers. An upgraded scheme is further proposed by splitting each transmission block into two stages. The first stage is exploited for ISAC transmission, where a wide beam is adopted for both communication and sensing. Based on the sensed results at the first stage, the second stage is dedicated to communication by adopting a pencil-sharp beam, yielding a significant improvement of the achievable rate. We further reveal the inherent tradeoff between the two stages in terms of their durations, and develop an optimal time allocation strategy that maximizes the average achievable rate. Finally, numerical results are provided to verify the superiorities of proposed schemes over the state-of-the-art methods.
Fast Spatio-temporal Compression of Dynamic 3D Meshes
Authors: Gerasimos Arvanitis, Aris S. Lalos, Konstantinos Moustakas
Date: 2021-11-19 00:00:00

3D representations of highly deformable 3D models, such as dynamic 3D meshes, have recently become very popular due to their wide applicability in various domains. This trend inevitably leads to a demand for storage and transmission of voluminous data sets, making the need for the design of a robust and reliable compression scheme a necessity. In this work, we present an approach for dynamic 3D mesh compression, that effectively exploits the spatio-temporal coherence of animated sequences, achieving low compression ratios without noticeably affecting the visual quality of the animation. We show that, on contrary to mainstream approaches that either exploit spatial (e.g., spectral coding) or temporal redundancies (e.g., PCA-based method), the proposed scheme, achieves increased efficiency, by projecting the differential coordinates sequence to the subspace of the covariance of the point trajectories. An extensive evaluation study, using different dynamic 3D models, highlights the benefits of the proposed approach in terms of both execution time and reconstruction quality, providing extremely low bit-per-vertex per-frame (bpvf) rates.
Beamforming using Digital Piezoelectric MEMS Microphone Array
Authors: Ricky Leman, Ben Travaglione, Melinda Hodkiewicz
Date: 2021-11-19 00:00:00

The recent explosion in low-cost, low-power wireless microcontrollers, coupled with low-power, robust MEMS sensors has opened up the opportunity to create new forms of low-cost Industrial Internet-of-Things (IIoT) devices for condition monitoring. Piezoelectric MEMS microphones constructed with a cantilever diaphragm are a potential solution against failure modes, such as water and dust ingress, that have challenged the use of capacitive MEMS microphones in industrial applications. In this paper, we couple a pair of piezoelectric MEMS microphones to a COTS microcontroller to create a stand-alone microphone array capable of discerning the direction of a noise source. The microphone array is designed to acquire sound data without aliasing at frequencies of 2000 Hz or below. Testing is conducted in an anechoic chamber. We compare the performance of this microphone array to a simple idealized theoretical model. The experimental results obtained in the anechoic chamber compare well with the theoretical model. The work stands as a proof-of-principle. By providing detailed information on how we coupled the sensors to a COTS microcontroller, and the open-source code used to process the data, we hope that others will be able to build upon this work by expanding on both the number and type of sensors used.
Golden rhythms as a theoretical framework for cross-frequency organization
Authors: Mark A. Kramer
Date: 2021-11-18 00:00:00

While brain rhythms appear fundamental to brain function, why brain rhythms consistently organize into the small set of discrete frequency bands observed remains unknown. Here we propose that rhythms separated by factors of the golden ratio ($\phi=(1+ \sqrt{5})/2$) optimally support segregation and cross-frequency integration of information transmission in the brain. Organized by the golden ratio, pairs of transient rhythms support multiplexing by reducing interference between separate communication channels, and triplets of transient rhythms support integration of signals to establish a hierarchy of cross-frequency interactions. We illustrate this framework in simulation and apply this framework to propose four hypotheses.
Inference of population-level disease transmissibility from household-structured symptom onset data
Authors: P. G. Ballard, A. J. Black, J. V. Ross
Date: 2021-11-19 00:00:00

First Few X (FFX) studies collect household-stratified data in the early stages of a pandemic, in order to infer severity and transmissibility of an emerging disease. We present a Bayesian method to approximately infer population-level transmissibility for the first time from such data; previous studies have only inferred household-level transmissibility. To do this we perform the inference at two levels, assuming one transmission rate parameter for within-household infection, and another transmission rate parameter for infection between different households. We use a simplifying assumption: that between-household infections always occur in naive households; while still performing full joint inference on the within-household infection parameters. In addition, a novel technique is used to remove systematic bias when the number of new infections per day is growing or decaying, as is common in real outbreaks, without the need for contemporaneous estimates of the serial interval. The method is validated on simulated data and is shown to perform well, even when the number of infected households is relatively small.
Adaptive ratchets and the evolution of molecular complexity
Authors: Tom Röschinger, Roberto Morán Tovar, Simone Pompei, Michael Lässig
Date: 2021-11-18 00:00:00

Biological systems have evolved to amazingly complex states, yet we do not understand in general how evolution operates to generate increasing genetic and functional complexity. Molecular recognition sites are short genome segments or peptides binding a cognate recognition target of sufficient sequence similarity. Such sites are simple, ubiquitous modules of sequence information, cellular function, and evolution. Here we show that recognition sites, if coupled to a time-dependent target, can rapidly evolve to complex states with larger code length and smaller coding density than sites recognising a static target. The underlying fitness model contains selection for recognition, which depends on the sequence similarity between site and target, and a uniform cost per unit of code length. Site sequences are shown to evolve in a specific adaptive ratchet, which produces selection of different strength for code extensions and compressions. Ratchet evolution increases the adaptive width of evolved sites, accelerating the adaptation to moving targets and facilitating refinement and innovation of recognition functions. We apply these results to the recognition of fast-evolving antigens by the human immune system. Our analysis shows how molecular complexity can evolve as a collateral to selection for function in a dynamic environment.
Pricing S&P 500 Index Options with Lévy Jumps
Authors: Bin Xie, Weiping Li, Nan Liang
Date: 2021-11-19 00:00:00

We analyze various jumps for Heston model, non-IID model and three L\'evy jump models for S&P 500 index options. The L\'evy jump for the S&P 500 index options is inevitable from empirical studies. We estimate parameters from in-sample pricing through SSE for the BS, SV, SVJ, non-IID and L\'evy (GH, NIG, CGMY) models by the method of Bakshi et al. (1997), and utilize them for out-of-sample pricing and compare these models. The sensitivities of the call option pricing for the L\'evy models with respect to parameters are presented. Empirically, we show that the NIG model, SV and SVJ models with estimated volatilities outperform other models for both in-sample and out-of-sample periods. Using the in-sample optimized parameters, we find that the NIG model has the least SSE and outperforms the rest models on one-day prediction.
Assessing the impact of the COVID-19 shock on a stochastic multi-population mortality model
Authors: Jens Robben, Katrien Antonio, Sander Devriendt
Date: 2021-11-19 00:00:00

We aim to assess the impact of a pandemic data point on the calibration of a stochastic multi-population mortality projection model and its resulting projections for future mortality rates. Throughout the paper we put focus on the Li & Lee mortality model, which has become a standard for projecting mortality in Belgium and the Netherlands. We calibrate this mortality model on annual deaths and exposures at the level of individual ages. This type of mortality data is typically collected, produced and reported with a significant delay of -- for some countries -- several years on a platform such as the Human Mortality Database. To enable a timely evaluation of the impact of a pandemic data point we have to rely on other data sources (e.g. the Short-Term Mortality Fluctuations Data series) that swiftly publish weekly mortality data collected in age buckets. To be compliant with the design and calibration strategy of the Li & Lee model, we have to transform the weekly mortality data collected in age buckets to yearly, age-specific observations. Therefore, our paper constructs a protocol to ungroup the deaths and exposures registered in age buckets to individual ages. To evaluate the impact of a pandemic shock, like COVID-19 in the year 2020, we weigh this data point in either the calibration or projection step. Obviously, the more weight we place on this data point, the more impact we observe on future estimated mortality rates and life expectancies. Our paper allows to quantify this impact and provides actuaries and actuarial associations with a framework to generate scenarios of future mortality under various assessments of the pandemic data point.
Multimodal Emotion Recognition with High-level Speech and Text Features
Authors: Mariana Rodrigues Makiuchi, Kuniaki Uto, Koichi Shinoda
Date: 2021-09-29 00:00:00
Tasks: Disentanglement, Emotion Recognition, Multimodal Emotion Recognition, Representation Learning, Vocal Bursts Intensity Prediction

Automatic emotion recognition is one of the central concerns of the Human-Computer Interaction field as it can bridge the gap between humans and machines. Current works train deep learning models on low-level data representations to solve the emotion recognition task. Since emotion datasets often have a limited amount of data, these approaches may suffer from overfitting, and they may learn based on superficial cues. To address these issues, we propose a novel cross-representation speech model, inspired by disentanglement representation learning, to perform emotion recognition on wav2vec 2.0 speech features. We also train a CNN-based model to recognize emotions from text features extracted with Transformer-based models. We further combine the speech-based and text-based results with a score fusion approach. Our method is evaluated on the IEMOCAP dataset in a 4-class classification problem, and it surpasses current works on speech-only, text-only, and multimodal emotion recognition.
Models and Tasks for Human-Centered Machine Translation
Authors: Marine Carpuat
Date: 2021-09-01 00:00:00
Proceeding: MMTLRL (RANLP) 2021 9
Tasks: Machine Translation, Sentence, Text Generation, Translation

In this talk, I will describe current research directions in my group that aim to make machine translation (MT) more human-centered. Instead of viewing MT solely as a task that aims to transduce a source sentence into a well-formed target language equivalent, we revisit all steps of the MT research and development lifecycle with the goal of designing MT systems that are able to help people communicate across language barriers. I will present methods to better characterize the parallel training data that powers MT systems, and how the degree of equivalence impacts translation quality. I will introduce models that enable flexible conditional language generation, and will discuss recent work on framing machine translation tasks and evaluation to center human factors.
Multiple Captions Embellished Multilingual Multi-Modal Neural Machine Translation
Authors: Salam Michael Singh, Loitongbam Sanayai Meetei, Thoudam Doren Singh, Sivaji Bandyopadhyay
Date: 2021-09-01 00:00:00
Proceeding: MMTLRL (RANLP) 2021 9
Tasks: Cross-Lingual Transfer, Diversity, Machine Translation, Translation, Word Translation

Neural machine translation based on bilingual text with limited training data suffers from lexical diversity, which lowers the rare word translation accuracy and reduces the generalizability of the translation system. In this work, we utilise the multiple captions from the Multi-30K dataset to increase the lexical diversity aided with the cross-lingual transfer of information among the languages in a multilingual setup. In this multilingual and multimodal setting, the inclusion of the visual features boosts the translation quality by a significant margin. Empirical study affirms that our proposed multimodal approach achieves substantial gain in terms of the automatic score and shows robustness in handling the rare word translation in the pretext of English to/from Hindi and Telugu translation tasks.
Malta National Language Technology Platform: A vision for enhancing Malta’s official languages using Machine Translation
Authors: Keith Cortis, Judie Attard, Donatienne Spiteri
Date: 2021-09-01 00:00:00
Proceeding: MMTLRL (RANLP) 2021 9
Tasks: Machine Translation, Translation

In this paper we introduce a vision towards establishing the Malta National Language Technology Platform; an ongoing effort that aims to provide a basis for enhancing Malta’s official languages, namely Maltese and English, using Machine Translation. This will contribute towards the current niche of Language Technology support for the Maltese low-resource language, across multiple computational linguistics fields, such as speech processing, machine translation, text analysis, and multi-modal resources. The end goals are to remove language barriers, increase accessibility, foster cross-border services, and most importantly to facilitate the preservation of the Maltese language.
Low Resource Multimodal Neural Machine Translation of English-Hindi in News Domain
Authors: Loitongbam Sanayai Meetei, Thoudam Doren Singh, Sivaji Bandyopadhyay
Date: 2021-09-01 00:00:00
Proceeding: MMTLRL (RANLP) 2021 9
Tasks: Machine Translation, Multimodal Machine Translation, NMT, Translation

Incorporating multiple input modalities in a machine translation (MT) system is gaining popularity among MT researchers. Unlike the publicly available dataset for Multimodal Machine Translation (MMT) tasks, where the captions are short image descriptions, the news captions provide a more detailed description of the contents of the images. As a result, numerous named entities relating to specific persons, locations, etc., are found. In this paper, we acquire two monolingual news datasets reported in English and Hindi paired with the images to generate a synthetic English-Hindi parallel corpus. The parallel corpus is used to train the English-Hindi Neural Machine Translation (NMT) and an English-Hindi MMT system by incorporating the image feature paired with the corresponding parallel corpus. We also conduct a systematic analysis to evaluate the English-Hindi MT systems with 1) more synthetic data and 2) by adding back-translated data. Our finding shows improvement in terms of BLEU scores for both the NMT (+8.05) and MMT (+11.03) systems.
Multimodal Simultaneous Machine Translation
Authors: Lucia Specia
Date: 2021-09-01 00:00:00
Proceeding: MMTLRL (RANLP) 2021 9
Tasks: Machine Translation, Translation

Simultaneous machine translation (SiMT) aims to translate a continuous input text stream into another language with the lowest latency and highest quality possible. Therefore, translation has to start with an incomplete source text, which is read progressively, creating the need for anticipation. In this talk I will present work where we seek to understand whether the addition of visual information can compensate for the missing source context. We analyse the impact of different multimodal approaches and visual features on state-of-the-art SiMT frameworks, including fixed and dynamic policy approaches using reinforcement learning. Our results show that visual context is helpful and that visually-grounded models based on explicit object region information perform the best. Our qualitative analysis illustrates cases where only the multimodal systems are able to translate correctly from English into gender-marked languages, as well as deal with differences in word order, such as adjective-noun placement between English and French.