Abstract

Many real-world systems can be modeled as dynamic graphs, where nodes and edges evolve over time, requiring specialized models to capture their evolving dynamics in risk-sensitive applications effectively. Graph neural networks (GNNs) for temporal graphs are one such category of specialized models. For the first time, our approach integrates a reject option strategy within the framework of GNNs for continuous-time dynamic graphs (CTDGs). This allows the model to strategically abstain from making predictions when the uncertainty is high and confidence is low, thus minimizing the risk of critical misclassification and enhancing the results and reliability. We propose a coverage-based abstention prediction model to implement the reject option that maximizes prediction within a specified coverage. It improves the prediction score for link prediction and node classification tasks. Temporal GNNs deal with extremely skewed datasets for the next state prediction or node classification task. In the case of class imbalance, our method can be further tuned to provide a higher weight to the minority class. Exhaustive experiments are presented on four datasets for dynamic link prediction and two datasets for dynamic node classification tasks. This demonstrates the effectiveness of our approach in improving the reliability and area under the curve (AUC)/average precision (AP) scores for predictions in dynamic graph scenarios. The results highlight our model's ability to efficiently handle the trade-offs between prediction confidence and coverage, making it a dependable solution for applications requiring high precision in dynamic and uncertain environments.

Abstract

Link prediction can help rectify inaccuracies in various graph algorithms, stemming from unaccounted-for or overlooked links within networks. However, many existing works use a baseline approach, which incurs unnecessary computational costs due to its high time complexity. Further, many studies focus on smaller graphs, which can lead to misleading conclusions. This submission introduces our parallel approach, called LHub, which predict links using neighborhood-based similarity measures on large graphs. LHub is a heuristic approach that disregards large hubs, based on the idea that high-degree nodes contribute little similarity among their neighbors. On a server equipped with dual 16-core Intel Xeon Gold 6226R processors, LHub is on average 1019x faster than not disregarding hubs, especially on web graphs and social networks, while maintaining similar prediction accuracy. Notably, LHub achieves a link prediction rate of 38.1M edges/s and improves performance at a rate of 1.6x for every doubling of threads.

Abstract

Efficient IO techniques are crucial in high-performance graph processing frameworks like Gunrock and Hornet, as fast graph loading can help minimize processing time and reduce system/cloud usage charges. This research study presents approaches for efficiently reading an Edgelist from a text file and converting it to a Compressed Sparse Row (CSR) representation. On a server with dual 16-core Intel Xeon Gold 6226R processors and Seagate Exos 10e2400 HDDs, our approach, which we term as GVEL, outperforms Hornet, Gunrock, and PIGO by significant margins in CSR reading, exhibiting an average speedup of 78x, 112x, and 1.8x, respectively. For Edgelist reading, GVEL is 2.6x faster than PIGO on average, and achieves an Edgelist read rate of 1.9 billion edges/s. For every doubling of threads, GVEL improves performance at an average rate of 1.9x and 1.7x for reading Edgelist and reading CSR respectively.

Abstract

Community detection is the problem of identifying natural divisions in networks. Efficient parallel algorithms for this purpose are crucial in various applications, particularly as datasets grow to substantial scales. This paper presents an optimized parallel implementation of the Label Propagation Algorithm (LPA), a high speed community detection method, for shared memory multicore systems. On a server equipped with dual 16-core Intel Xeon Gold 6226R processors, our LPA, which we term as GVE-LPA, outperforms FLPA, igraph LPA, and NetworKit LPA by 139x, 97000x, and 40x respectively - achieving a processing rate of 1.4B edges/s on a 3.8B edge graph. In addition, GVE-LPA scales at a rate of 1.7x every doubling of threads.

Abstract

Natural ventilation (NV) is vital for optimizing energy efficiency, particularly when outdoor conditions are favourable. In highly polluted regions like National Capital Regions of Delhi (Delhi-NCR), occupants often avoid NV during pollution episodes, relying instead on mechanical systems. This behaviour stems from the assumption that outdoor air is consistently unsuitable for ventilation, even when pollution levels are within acceptable limits. As a result, energy consumption increases, even during periods when outdoor air could support NV. This study integrates PM2.5 and PM10 data to develop a pollution-aware NV strategy for residential buildings. Behavioural insights gathered from detailed ethnographic interviews in Delhi-NCR highlight occupant tendencies to keep windows closed during pollution episodes, often based on perceived air quality rather than actual data. While previous studies have examined the effects of pollution on NV, few have directly linked measured air quality data with real occupant behaviour in residential settings. The proposed framework addresses these behavioural patterns. If outdoor PM2.5 and PM10 levels exceed standard thresholds, occupants are advised to close windows to maintain indoor air quality. Alternatively, when these levels fall below predefined thresholds, occupants are encouraged to open windows, highlighting the potential for energy savings. For the above-mentioned scenarios building energy simulation was employed to simulate NV strategies in a mixed mode building. This pollution-aware approach bridges the gap between occupant behaviour and actual environmental conditions, promoting energy-efficient ventilation practices in regions affected by air pollution. Our results demonstrate that aligning behavioural NV strategies with actual data addresses air quality concerns, contributing to energy-efficient and occupant-centric ventilation solutions.

Abstract

A significant task that municipalities or equivalent government organizations across the world perform is street addressing including naming of roads. Due to unstructured ways in which towns and cities grow, this process needs significant thought and effort which in reality results in major delays in terms of action taken on these issues. Meanwhile, the local populace which needs some naming convention for practical needs may take the initiative to arrive at reasonable names for the roads within their vicinity based on their local knowledge. This can result in significant sections of the road network without an official name or named after a landmark or a famous personality in many places across the world. The past 2-3 decades have seen an increasing digitisation of government activities. However, a lot of the street addressing and road naming systems and conventions were derived before the digitisation era, which in most cases means that computational parsability of the addresses or road names that would be important for digital processing would not be accounted for. There has been a significant increase in importance and usage of location-based geocoding services like what3words, Zippr and plus codes in recent times. However, these services provide alphanumeric code-based addressing which is not intuitive for human understanding, lacks directionality, does not account for existing address information nor the geometric relations of road topology. In this paper, we propose usage of (modified versions of) well known AI search algorithms for automated road numbering and evaluate them based on spatial proximity and connectivity on roadmaps of three different cities.

Abstract

Missing values in time-series is a frequently occurring problem in multi-sensor data analysis. The current state-of-the-art imputation networks don’t generalize well across the benchmarks. Further, some directly operate on space-time product graphs which may minimize the information loss but are prohibitively expensive. We propose Product Graph U-networks using Temporal pooling for Spa- tiotemporal imputation (P-GUTS). It uses pooled representations of the space-time sequence in the bottleneck part of the U-network and is memory efficient. Since datasets can have differing levels of redundancy, relying on a single view (pooled representation) of the data can be limiting. Therefore, P-GUTS uses multiple U-Nets with different pooling factors and aggregates the representations. We demonstrate the effectiveness of P-GUTS on multiple real-world imputation datasets and robustness across increasing missing rates. P-GUTS also gives encouraging results in spatiotemporal forecast- ing.

Abstract

The scarcity of high-quality annotated data presents a sig- nificant challenge in developing effective end-to-end speech- to-text translation (ST) systems, particularly for low-resource languages. This paper explores the hypothesis that weakly la- beled data can be used to build ST models for low-resource lan- guage pairs. We constructed speech-to-text translation datasets with the help of bitext mining using state-of-the-art sentence encoders. We mined the multilingual Shrutilipi corpus to build Shrutilipi-anuvaad, a dataset comprising ST data for lan- guage pairs Bengali-Hindi, Malayalam-Hindi, Odia-Hindi, and Telugu-Hindi. We created multiple versions of training data with varying degrees of quality and quantity to investigate the effect of quality versus quantity of weakly labeled data on ST model performance. Results demonstrate that ST systems can be built using weakly labeled data, with performance compa- rable to massive multi-modal multilingual baselines such as SONAR and SeamlessM4T.

Abstract

The National Institutional Ranking Framework (NIRF) provides a comprehensive evaluation of colleges across India based on various parameters such as teaching, learning, resources, research, and outreach. It integrates these parameters by giving a fixed priority to each of them. In today’s competitive academic landscape, choosing the right college is a crucial decision for students seeking higher education. This depends on several factors specific to each student such as their social background, location, economic status and rank in the qualifying examination, etc.This research introduces a novel approach to enhance the utility of NIRF data by creating user-specific rankings tailored to individual preferences. By incorporating user-defined criteria such as median salary, number of students placed, facilities for Physically Challenged Students (PCS), faculty strength, research funding, the proposed system generates personalized rankings that align with the unique needs and aspirations of each student.Our system utilizes a novel skyline-based approach and analyzes the NIRF data alongside user preferences to generate dynamic rankings that adapt to evolving student priorities. We show multiple use-cases to demonstrate the utility of our approach in real-world scenarios, and study the way colleges are ranked for different user preferences. Our study shows that the college rankings so obtained can be quite different from the standard NIRF ranking.

Abstract

Computer-Assisted Language Learning systems provide speech exaggerating at mispronounced word locations as a feedback to the L2 learners. Traditionally, expert speakers recordings (which limit the scalability) are considered for this task though there are advancements in text-to-speech (TTS) that can generate native like natural sounding speech. To address these, this work proposes two novel controllable strategies for scalable speech exaggeration. One strategy is direct speech exaggeration that incorporates the proposed label conditioned tokenization in GlowTTS. Another strategy is cascading the state-of-the-art TTS to a WORLD vocoder with proposed energy and duration modifications. A subset of Tatoeba corpus, that we annotated with prominent words, is used for experimentation. Automatic and manual assessment reveals that the exaggerated speech quality from both direct and cascaded strategy with duration modification is closer to the prominent words in the native speaker's speech.