245 research outputs found
Semantic spaces revisited: investigating the performance of auto-annotation and semantic retrieval using semantic spaces
Semantic spaces encode similarity relationships between objects as a function of position in a mathematical space. This paper discusses three different formulations for building semantic spaces which allow the automatic-annotation and semantic retrieval of images. The models discussed in this paper require that the image content be described in the form of a series of visual-terms, rather than as a continuous feature-vector. The paper also discusses how these term-based models compare to the latest state-of-the-art continuous feature models for auto-annotation and retrieval
Integration and coordination in a cognitive vision system
In this paper, we present a case study that exemplifies
general ideas of system integration and coordination.
The application field of assistant technology provides an
ideal test bed for complex computer vision systems including
real-time components, human-computer interaction, dynamic
3-d environments, and information retrieval aspects.
In our scenario the user is wearing an augmented reality device
that supports her/him in everyday tasks by presenting
information that is triggered by perceptual and contextual
cues. The system integrates a wide variety of visual functions
like localization, object tracking and recognition, action
recognition, interactive object learning, etc. We show
how different kinds of system behavior are realized using
the Active Memory Infrastructure that provides the technical
basis for distributed computation and a data- and eventdriven
integration approach
Modular Deep Learning
Transfer learning has recently become the dominant paradigm of machine
learning. Pre-trained models fine-tuned for downstream tasks achieve better
performance with fewer labelled examples. Nonetheless, it remains unclear how
to develop models that specialise towards multiple tasks without incurring
negative interference and that generalise systematically to non-identically
distributed tasks. Modular deep learning has emerged as a promising solution to
these challenges. In this framework, units of computation are often implemented
as autonomous parameter-efficient modules. Information is conditionally routed
to a subset of modules and subsequently aggregated. These properties enable
positive transfer and systematic generalisation by separating computation from
routing and updating modules locally. We offer a survey of modular
architectures, providing a unified view over several threads of research that
evolved independently in the scientific literature. Moreover, we explore
various additional purposes of modularity, including scaling language models,
causal inference, programme induction, and planning in reinforcement learning.
Finally, we report various concrete applications where modularity has been
successfully deployed such as cross-lingual and cross-modal knowledge transfer.
Related talks and projects to this survey, are available at
https://www.modulardeeplearning.com/
Active-Learning-as-a-Service: An Efficient MLOps System for Data-Centric AI
The success of today's AI applications requires not only model training
(Model-centric) but also data engineering (Data-centric). In data-centric AI,
active learning (AL) plays a vital role, but current AL tools can not perform
AL tasks efficiently. To this end, this paper presents an efficient MLOps
system for AL, named ALaaS (Active-Learning-as-a-Service). Specifically, ALaaS
adopts a server-client architecture to support an AL pipeline and implements
stage-level parallelism for high efficiency. Meanwhile, caching and batching
techniques are employed to further accelerate the AL process. In addition to
efficiency, ALaaS ensures accessibility with the help of the design philosophy
of configuration-as-a-service. It also abstracts an AL process to several
components and provides rich APIs for advanced users to extend the system to
new scenarios. Extensive experiments show that ALaaS outperforms all other
baselines in terms of latency and throughput. Further ablation studies
demonstrate the effectiveness of our design as well as ALaaS's ease to use. Our
code is available at \url{https://github.com/MLSysOps/alaas}.Comment: 8 pages, 7 figure
Classification of Explainable Artificial Intelligence Methods through Their Output Formats
Machine and deep learning have proven their utility to generate data-driven models with high accuracy and precision. However, their non-linear, complex structures are often difficult to interpret. Consequently, many scholars have developed a plethora of methods to explain their functioning and the logic of their inferences. This systematic review aimed to organise these methods into a hierarchical classification system that builds upon and extends existing taxonomies by adding a significant dimension—the output formats. The reviewed scientific papers were retrieved by conducting an initial search on Google Scholar with the keywords “explainable artificial intelligence”; “explainable machine learning”; and “interpretable machine learning”. A subsequent iterative search was carried out by checking the bibliography of these articles. The addition of the dimension of the explanation format makes the proposed classification system a practical tool for scholars, supporting them to select the most suitable type of explanation format for the problem at hand. Given the wide variety of challenges faced by researchers, the existing XAI methods provide several solutions to meet the requirements that differ considerably between the users, problems and application fields of artificial intelligence (AI). The task of identifying the most appropriate explanation can be daunting, thus the need for a classification system that helps with the selection of methods. This work concludes by critically identifying the limitations of the formats of explanations and by providing recommendations and possible future research directions on how to build a more generally applicable XAI method. Future work should be flexible enough to meet the many requirements posed by the widespread use of AI in several fields, and the new regulation
Speeding up Adaboost object detection with motion segmentation and Haar feature acceleration
A key challenge in a surveillance system is the object detection task. Object detection in general is a non-trivial problem. A sub-problem within the broader context of object detection which many researchers focus on is face detection. Numerous techniques have been proposed for face detection. One of the better performing algorithms is proposed by Viola et. al. This algorithm is based on Adaboost and uses Haar features to detect objects. The main reason for its popularity is very low false positive rates and the fact that the classifier network can be trained for any detection task. The use of Haar basis functions to represent key object features is the key to its success. The basis functions are organized as a network to form a strong classifier. To detect objects, this technique divides each input image into non-overlapping sub-windows and the strong classifier is applied to each sub-window to detect the presence of an object. The process is repeated at multiple scales of the input image to detect objects of various sizes. In this thesis we propose an object detection system that uses object segmentation as a preprocessing step. We use Mixture of Gaussians (MoG) proposed by Staffer et. al. for object segmentation. One key advantage with using segmentation to extract image regions of interest is that it reduces the number of search windows sent to detection task, thereby reducing the computational complexity and the execution time. Moreover, owing to the computational complexity of both the segmentation and detection algorithms we used in the system, we propose hardware architectures for accelerating key computationally intensive blocks. In this thesis we propose hardware architecture for MoG and also for a key compute intensive block within the adaboost algorithm corresponding to the Haar feature computation
Notions of explainability and evaluation approaches for explainable artificial intelligence
Explainable Artificial Intelligence (XAI) has experienced a significant growth over the last few years. This is due to the widespread application of machine learning, particularly deep learning, that has led to the development of highly accurate models that lack explainability and interpretability. A plethora of methods to tackle this problem have been proposed, developed and tested, coupled with several studies attempting to define the concept of explainability and its evaluation. This systematic review contributes to the body of knowledge by clustering all the scientific studies via a hierarchical system that classifies theories and notions related to the concept of explainability and the evaluation approaches for XAI methods. The structure of this hierarchy builds on top of an exhaustive analysis of existing taxonomies and peer-reviewed scientific material. Findings suggest that scholars have identified numerous notions and requirements that an explanation should meet in order to be easily understandable by end-users and to provide actionable information that can inform decision making. They have also suggested various approaches to assess to what degree machine-generated explanations meet these demands. Overall, these approaches can be clustered into human-centred evaluations and evaluations with more objective metrics. However, despite the vast body of knowledge developed around the concept of explainability, there is not a general consensus among scholars on how an explanation should be defined, and how its validity and reliability assessed. Eventually, this review concludes by critically discussing these gaps and limitations, and it defines future research directions with explainability as the starting component of any artificial intelligent system
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