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In the task of fashion compatibility prediction, the goal is to pick an item from a candidate list to complement a partial outfit in the most appealing manner. Existing fashion compatibility recommendation work comprehends clothing images in a single metric space and lacks detailed understanding of users’ preferences in different contexts. To address this problem, we propose a novel Metric-Aware Explainable Graph Network (MAEG). In MAEG, we leverage a Latent Semantic Extraction Network (LSEN) to obtain representations of items in the metric-aware latent semantic space. Then, we develop a graph filtering network and Pairwise Preference Attention (PPA) module to model the interactions between users’ preferences and contextual information. With MAEG, we can provide recommendation to users as well as explain how each item and factor contribute to the final prediction. Extensive experiments on two large-scale real-world datasets reveal that MAEG not only outperforms the state-of-the-art methods, but also provides interpretable insights by highlighting the role of semantic attributes and contextual relationships among items.

MCL Director, Professor Kuo, gave an invited speech at Kyoto University on December 19, 2019. The title of his speech was “From Feedforward-Designed Convolutional Neural Networks (FF-CNNs) to Successive Subspace Learning (SSL)”.  Professor Kuo’s visit to Kyoto University was hosted by Professor Tatsuya Kawahara. The lecture was also an event of IEEE SPS Kansai Chapter.

The abstract of his speech is given below. “Given a convolutional neural network (CNN) architecture, its network parameters are typically determined by backpropagation (BP). The underlying mechanism remains to be a black-box after a large amount of theoretical investigation. In this talk, I will first describe a new interpretable feedforward (FF) design with the LeNet-5 as an example. The FF-designed CNN is a data-centric approach that derives network parameters based on training data statistics layer by layer in a one-pass feedforward manner. To build the convolutional layers, we develop a new signal transform, called the Saab (Subspace approximation with adjusted bias) transform. The bias in filter weights is chosen to annihilate nonlinearity of the activation function. To build the fully-connected (FC) layers, we adopt a label-guided linear least squared regression (LSR) method. To generalize the FF design idea furthermore, we present the notion of “successive subspace learning (SSL)” and present a couple of concrete methods for image and point cloud classification. Experimental results are given to demonstrate the competitive performance of the SSL-based systems. Similarities and differences between SSL and deep learning (DL) are compared.”

MCL Director, Professor Kuo, was invited by Korean National IT Industry Promotion Agency (NIPA) to deliver a keynote speech at the Grand Cloud Conference, Seoul, Korea on Dec. 3, 2019. The title of Professor Kuo’s talk was “AI Cloud Strategy for Government and Industry”. Here is the abstract.

There have been many successful artificial intelligence (AI) stories in the last decade due to big data analytics and the resurgence of neural-network-based deep learning. For clarity, I would like to give my own definition about AI. That is, AI is not about competing with humans in terms of intelligence but an advanced form of “automation”, which leverages both data and domain knowledge to achieve domain-specific tasks more effectively. Then, I will discuss the AI deployment strategy. It is centered around “smart environments” such as smart homes, smart cities, etc. We can leverage sensors, Internet of Things (IoT) and 5G infrastructures to acquire a large amount of data for better decision making. After that, I will mention three R&D opportunities: 1) explainable AI, 2) integrated rule-based/data-driven methodology and 3) federated learning. For the first topic, AI is not necessarily dependent upon deep learning, which is a black box. We are working on an alternative approach, called Successive Subspace Learning (SSL), to solve the big data problem at USC. SSL is mathematically transparent and expandable depending on the training data sizes and classes. It has great potential. For the second topic, I want to emphasize that big data is helpful but not sufficient by itself alone. It is more powerful to have an integration of the “rule-based” and the “data-driven” approaches. The integration allows better generalizability and robustness. The third topic is concerned with data-driven model training without [...]

Dr. Sachin Chachada, a former MCL alumnus, and Professor C.-C. Jay Kuo received the 2019 Sadaoki Furui Paper Award at the open ceremony of the 2019 APSIPA ASC held in Lanzhou, China, on November 19 for their paper below:
Sachin Chachada and C.-C. Jay Kuo, “Environmental sound recognition: a survey,” Published online: 15 December 2014, e14, APSIPA Trans. on Signal and Information Processing.
The paper has been cited by 107 in Google Scholar, the number of downloads in 2019 (to end of Sept.) is 1523. The abstract of the paper is given below.
Although research in audio recognition has traditionally focused on speech and music signals, the problem of environmental sound recognition (ESR) has received more attention in recent years. Research on ESR has significantly increased in the past decade. Recent work has focused on the appraisal of non-stationary aspects of environmental sounds, and several new features predicated on non-stationary characteristics have been proposed. These features strive to maximize their information content pertaining to signal’s temporal and spectral characteristics. Furthermore, sequential learning methods have been used to capture the long-term variation of environmental sounds. In this survey, we will offer a qualitative and elucidatory survey on recent developments. It includes four parts: (i) basic environmental sound-processing schemes, (ii) stationary ESR techniques, (iii) non-stationary ESR techniques, and (iv) performance comparison of selected methods. Finally, concluding remarks and future research and development trends in the ESR field will be given.

Recently, Professor Kuo and his students at MCL proposed a new machine learning methodology called successive subspace learning (SSL). The methodology has been widely adopted in MCL to solve image processing and computer vision problems. In 3D domain, we have observed a great success in point cloud classification task. In the PointHop paper, we develop an explainable machine learning method for point cloud classification. The classification baseline is composed by four PointHop units, we construct the local-to-global attribute building process and use saab transform to control the dimension growth in each unit. We compare the test performance on ModelNet40 with the state-of-the-art methods, our method obtains comparable performance with the others while demands much less training time. For instance, PointNet costs about 5 hours to train, while ours only takes 20 minutes to train on the same dataset. The advantages of the methodology are very clear: interpretable and much less computation complexity.

The success in point cloud classification encourages us to go deeper in 3D domain. Therefore, we further look at the segmentation task which needs to assign label to each point in the point cloud. Referring to the common image segmentation network, we use the point cloud classification baseline as an encoder and add a decoder to complete segmentation. After building local neighboring regions and extracting local attributes from neighboring points in the encoder, the features are interpolated back to finest scale layer by layer with skip connections between same scales in the decoder. Also, saab transform is adopted between layers as feedfoward convolution to control the rapid growth of the feature dimension.

Our method also has the advantage of task-agnostic ability. Specifically, by learning the parameters in a one-pass manner, our [...]