South America
Writer adaptation for offline text recognition: An exploration of neural network-based methods
van der Werff, Tobias, Dhali, Maruf A., Schomaker, Lambert
Handwriting recognition has seen significant success with the use of deep learning. However, a persistent shortcoming of neural networks is that they are not well-equipped to deal with shifting data distributions. In the field of handwritten text recognition (HTR), this shows itself in poor recognition accuracy for writers that are not similar to those seen during training. An ideal HTR model should be adaptive to new writing styles in order to handle the vast amount of possible writing styles. In this paper, we explore how HTR models can be made writer adaptive by using only a handful of examples from a new writer (e.g., 16 examples) for adaptation. Two HTR architectures are used as base models, using a ResNet backbone along with either an LSTM or Transformer sequence decoder. Using these base models, two methods are considered to make them writer adaptive: 1) model-agnostic meta-learning (MAML), an algorithm commonly used for tasks such as few-shot classification, and 2) writer codes, an idea originating from automatic speech recognition. Results show that an HTR-specific version of MAML known as MetaHTR improves performance compared to the baseline with a 1.4 to 2.0 improvement in word error rate (WER). The improvement due to writer adaptation is between 0.2 and 0.7 WER, where a deeper model seems to lend itself better to adaptation using MetaHTR than a shallower model. However, applying MetaHTR to larger HTR models or sentence-level HTR may become prohibitive due to its high computational and memory requirements. Lastly, writer codes based on learned features or Hinge statistical features did not lead to improved recognition performance.
AnuraSet: A dataset for benchmarking Neotropical anuran calls identification in passive acoustic monitoring
Cañas, Juan Sebastián, Toro-Gómez, Maria Paula, Sugai, Larissa Sayuri Moreira, Restrepo, Hernán Darío Benítez, Rudas, Jorge, Bautista, Breyner Posso, Toledo, Luís Felipe, Dena, Simone, Domingos, Adão Henrique Rosa, de Souza, Franco Leandro, Neckel-Oliveira, Selvino, da Rosa, Anderson, Carvalho-Rocha, Vítor, Bernardy, José Vinícius, Sugai, José Luiz Massao Moreira, Santos, Carolina Emília dos, Bastos, Rogério Pereira, Llusia, Diego, Ulloa, Juan Sebastián
Global change is predicted to induce shifts in anuran acoustic behavior, which can be studied through passive acoustic monitoring (PAM). Understanding changes in calling behavior requires the identification of anuran species, which is challenging due to the particular characteristics of neotropical soundscapes. In this paper, we introduce a large-scale multi-species dataset of anuran amphibians calls recorded by PAM, that comprises 27 hours of expert annotations for 42 different species from two Brazilian biomes. We provide open access to the dataset, including the raw recordings, experimental setup code, and a benchmark with a baseline model of the fine-grained categorization problem. Additionally, we highlight the challenges of the dataset to encourage machine learning researchers to solve the problem of anuran call identification towards conservation policy.
Natural Language Instructions for Intuitive Human Interaction with Robotic Assistants in Field Construction Work
Park, Somin, Wang, Xi, Menassa, Carol C., Kamat, Vineet R., Chai, Joyce Y.
The introduction of robots is widely considered to have significant potential of alleviating the issues of worker shortage and stagnant productivity that afflict the construction industry. However, it is challenging to use fully automated robots in complex and unstructured construction sites. Human-Robot Collaboration (HRC) has shown promise of combining human workers' flexibility and robot assistants' physical abilities to jointly address the uncertainties inherent in construction work. When introducing HRC in construction, it is critical to recognize the importance of teamwork and supervision in field construction and establish a natural and intuitive communication system for the human workers and robotic assistants. Natural language-based interaction can enable intuitive and familiar communication with robots for human workers who are non-experts in robot programming. However, limited research has been conducted on this topic in construction. This paper proposes a framework to allow human workers to interact with construction robots based on natural language instructions. The proposed method consists of three stages: Natural Language Understanding (NLU), Information Mapping (IM), and Robot Control (RC). Natural language instructions are input to a language model to predict a tag for each word in the NLU module. The IM module uses the result of the NLU module and building component information to generate the final instructional output essential for a robot to acknowledge and perform the construction task. A case study for drywall installation is conducted to evaluate the proposed approach. The obtained results highlight the potential of using natural language-based interaction to replicate the communication that occurs between human workers within the context of human-robot teams.
RL4F: Generating Natural Language Feedback with Reinforcement Learning for Repairing Model Outputs
Akyürek, Afra Feyza, Akyürek, Ekin, Madaan, Aman, Kalyan, Ashwin, Clark, Peter, Wijaya, Derry, Tandon, Niket
Despite their unprecedented success, even the largest language models make mistakes. Similar to how humans learn and improve using feedback, previous work proposed providing language models with natural language feedback to guide them in repairing their outputs. Because human-generated critiques are expensive to obtain, researchers have devised learned critique generators in lieu of human critics while assuming one can train downstream models to utilize generated feedback. However, this approach does not apply to black-box or limited access models such as ChatGPT, as they cannot be fine-tuned. Moreover, in the era of large general-purpose language agents, fine-tuning is neither computationally nor spatially efficient as it results in multiple copies of the network. In this work, we introduce RL4F (Reinforcement Learning for Feedback), a multi-agent collaborative framework where the critique generator is trained to maximize end-task performance of GPT-3, a fixed model more than 200 times its size. RL4F produces critiques that help GPT-3 revise its outputs. We study three datasets for action planning, summarization and alphabetization and show relative improvements up to 10% in multiple text similarity metrics over other learned, retrieval-augmented or prompting-based critique generators.
Multiple Instance Learning via Iterative Self-Paced Supervised Contrastive Learning
Liu, Kangning, Zhu, Weicheng, Shen, Yiqiu, Liu, Sheng, Razavian, Narges, Geras, Krzysztof J., Fernandez-Granda, Carlos
Learning representations for individual instances when only bag-level labels are available is a fundamental challenge in multiple instance learning (MIL). Recent works have shown promising results using contrastive self-supervised learning (CSSL), which learns to push apart representations corresponding to two different randomly-selected instances. Unfortunately, in real-world applications such as medical image classification, there is often class imbalance, so randomly-selected instances mostly belong to the same majority class, which precludes CSSL from learning inter-class differences. To address this issue, we propose a novel framework, Iterative Self-paced Supervised Contrastive Learning for MIL Representations (ItS2CLR), which improves the learned representation by exploiting instance-level pseudo labels derived from the bag-level labels. The framework employs a novel self-paced sampling strategy to ensure the accuracy of pseudo labels. We evaluate ItS2CLR on three medical datasets, showing that it improves the quality of instance-level pseudo labels and representations, and outperforms existing MIL methods in terms of both bag and instance level accuracy. Code is available at https://github.com/Kangningthu/ItS2CLR
On the Need for a Language Describing Distribution Shifts: Illustrations on Tabular Datasets
Liu, Jiashuo, Wang, Tianyu, Cui, Peng, Namkoong, Hongseok
The performance of predictive models has been observed to degrade under distribution shifts in a wide range of applications, such as healthcare [8, 68, 56, 67], economics [28, 18], education [5], vision [55, 47, 64, 70], and language [46, 6]. Distribution shifts vary in type, typically defined as either a change in the marginal distribution of the covariates (X-shifts), or changes in the conditional relationship between the outcome and covariate (Y |X-shifts). Real-world scenarios comprise of both types of shifts. In computer vision [46, 37, 60, 30, 72], Y |X-shifts are less likely as Y is constructed from human labels given an input X. Due to the prevalence of X-shifts, the implicit goal of many researchers is to develop a single robust model that can generalize effectively across multiple domains, akin to humans. For tabular data, Y |X-shifts may arise because of missing variables and hidden confounders. For example, the prevalence of diseases among patients may be affected by covariates that are not recorded in medical datasets but vary among individuals, such as lifestyle factors (e.g., diet, exercise, smoking status) and socioeconomic status [31, 74, 67]. Under Y |X-shifts, there may be a fundamental trade-off between learning algorithms: to perform well on a target distribution, a model may have to necessarily perform worse on others. Algorithmically, typical methods for addressing Y |X-shifts include distributionally robust optimization (DRO) [11, 63, 21, 59, 20] and causal learning methods [54, 7, 62, 36].
CareFall: Automatic Fall Detection through Wearable Devices and AI Methods
Ruiz-Garcia, Juan Carlos, Tolosana, Ruben, Vera-Rodriguez, Ruben, Moro, Carlos
The aging population has led to a growing number of falls in our society, affecting global public health worldwide. This paper presents CareFall, an automatic Fall Detection System (FDS) based on wearable devices and Artificial Intelligence (AI) methods. CareFall considers the accelerometer and gyroscope time signals extracted from a smartwatch. Two different approaches are used for feature extraction and classification: i) threshold-based, and ii) machine learning-based. Experimental results on two public databases show that the machine learning-based approach, which combines accelerometer and gyroscope information, outperforms the threshold-based approach in terms of accuracy, sensitivity, and specificity. This research contributes to the design of smart and user-friendly solutions to mitigate the negative consequences of falls among older people.
A Mapping Study of Machine Learning Methods for Remaining Useful Life Estimation of Lead-Acid Batteries
Chevtchenko, Sérgio F, Rocha, Elisson da Silva, Cruz, Bruna, de Andrade, Ermeson Carneiro, de Araújo, Danilo Ricardo Barbosa
Energy storage solutions play an increasingly important role in modern infrastructure and lead-acid batteries are among the most commonly used in the rechargeable category. Due to normal degradation over time, correctly determining the battery's State of Health (SoH) and Remaining Useful Life (RUL) contributes to enhancing predictive maintenance, reliability, and longevity of battery systems. Besides improving the cost savings, correct estimation of the SoH can lead to reduced pollution though reuse of retired batteries. This paper presents a mapping study of the state-of-the-art in machine learning methods for estimating the SoH and RUL of lead-acid batteries. These two indicators are critical in the battery management systems of electric vehicles, renewable energy systems, and other applications that rely heavily on this battery technology. In this study, we analyzed the types of machine learning algorithms employed for estimating SoH and RUL, and evaluated their performance in terms of accuracy and inference time. Additionally, this mapping identifies and analyzes the most commonly used combinations of sensors in specific applications, such as vehicular batteries. The mapping concludes by highlighting potential gaps and opportunities for future research, which lays the foundation for further advancements in the field.
Stable Normative Explanations: From Argumentation to Deontic Logic
Di Florio, Cecilia, Governatori, Guido, Rotolo, Antonino, Sartor, Giovanni
This paper examines how a notion of stable explanation developed elsewhere in Defeasible Logic can be expressed in the context of formal argumentation. With this done, we discuss the deontic meaning of this reconstruction and show how to build from argumentation neighborhood structures for deontic logic where this notion of explanation can be characterised. Some direct complexity results are offered.
A Modal Logic for Explaining some Graph Neural Networks
Nunn, Pierre, Schwarzentruber, François
In this paper, we propose a modal logic in which counting modalities appear in linear inequalities. We show that each formula can be transformed into an equivalent graph neural network (GNN). We also show that each GNN can be transformed into a formula. We show that the satisfiability problem is decidable. We also discuss some variants that are in PSPACE.