Knowledge Distillation (KD) is considered as an efficient way to replace the parameter averaging in federated learning, aiming to handle the clients with heterogeneous model architectures. Relying on the prepared distillation datasets across clients and the server, KD may encounter impractical difficulties in real-world implementations. Existing works explore the data-free KD in federated learning, which generates the distillation datasets on-site. However, the distillation datasets with global data distribution generated by these state-of-the-art schemes cannot be adapted to local non-IID data. In this article, we propose a new Personalized Data-Free Knowledge Distillation, namely PDKD, for federated learning under heterogeneous models and data. PDKD solves the problem of model drift caused by the inconsistent distribution of distillation datasets and the local data by generating personalized distillation datasets for each client while protecting client data privacy. In addition, we design a distillation dataset update scheme that maximizes the difference between teacher and client outputs on distillation datasets to accomplish deeper knowledge transfer. Furthermore, in order to accomplish the co-evolution of the teacher model and the clients’ model, PDKD incorporates a mutual distillation scheme. Numerous experiments show that PDKD significantly outperforms several state-of-the-art algorithms, with an 18% improvement in prediction accuracy and has a much lower communication cost than the compared algorithms.

Gradient smoothing is an efficient approach to reducing noise in gradient-based model explanation methods. SmoothGrad adds Gaussian noise to mitigate much of this noise. However, the crucial hyperparameter in this method, the variance $\sigma$ of the Gaussian noise, is often set manually or determined using a heuristic approach. This results in the smoothed gradients containing extra noise introduced by the smoothing process. In this paper, we aim to analyze the noise and its connection to the out-of-range sampling in the smoothing process of SmoothGrad. Based on this insight, we propose AdaptGrad, an adaptive gradient smoothing method that controls out-of-range sampling to minimize noise. Comprehensive experiments, both qualitative and quantitative, demonstrate that AdaptGrad could effectively reduce almost all the noise in vanilla gradients compared to baseline methods. AdaptGrad is simple and universal, making it a practical solution to enhance gradient-based interpretability methods to achieve clearer visualization.

To assess the vulnerability of deep neural networks in the physical world, many studies have introduced adversarial examples and applied them to computer vision tasks such as object detection in recent years. Compared to patch-based adversarial attacks, camouflage-based attacks have received more and more attention due to their ability to attack detectors from multiple viewpoints. However, existing adversarial examples often rely on glass-box models and exhibit limited transferability to closed-box models, which remains a significant challenge. To address this issue, we propose the highly transferable camouflage attack, a novel physical adversarial attack framework designed to generate robust and efficient adversarial camouflage that can mislead object detectors in diverse scenarios. Specifically, we introduce a distraction method to distribute the features of the attention map between models, and propose enhanced transfer strategies to improve adversarial transferability through augmenting the input data and the attacked models. Extensive experiments demonstrate that our highly transferable camouflage attack can effectively mislead object detectors in both digital and physical worlds, enhancing the transferability of adversarial camouflage on multiple mainstream detectors.

Due to the collaborative machine learning nature of Federated Learning (FL), it enables the training of machine learning models on large-scale distributed datasets in edge computing environments. Nevertheless, the application of FL in edge computing still faces three crucial challenges: resource constraint, privacy leakage, and Byzantine failures. Unfortunately, current approaches lack the ability to effectively balance these three challenges. In this paper, we propose FedEdge, a cost-efficient and secure FL for edge computing. FedEdge contains two main mechanisms: adaptive compression perturbation and dynamic update filtering. The adaptive compression perturbation mechanism reduces the communication overhead, provides different levels of privacy protection for edge nodes, and prevents Byzantine attacks. The dynamic update filtering mechanism is used to further filter Byzantine attacks and limit the impact of adaptive compression perturbation on the global model performance. The experimental results on the MNIST, CIFAR-10, CIFAR-100, and CelebA datasets demonstrate the effectiveness of FedEdge against free-riders, label-flipping, and sign-flipping attacks. Theoretical analysis also demonstrate that FedEdge can still converge even when the majority of edge nodes are malicious.

Time series anomaly detection is one kind of critical time series analytical tasks, which is widely applied to various real-world applications. Recently, the diffusion models have shown promising performance on time series imputation for anomaly detection. And the high computing requirements of the diffusion models naturally extend their computation paradigm from the centralized computing to the cloud computing, and then further to JointCloud computing which allows the diffusion models to be deployed across multiple clouds. However, the JointCloud computing paradigm faces the challenge of task offloading over multiple nodes across multiple clouds. Unfortunately, most of existing task offloading methods overlook the dynamic nature of network conditions among clouds. To address this issue, we propose a time series anomaly detection approach named AdaDiffAD by adaptively segmenting diffusion models in JointCloud environment with dynamic network conditions. Specifically, we design a task offloading strategy by segmenting the denoising process of the diffusion model onto both the edge clouds and central clouds, and utilizing the edge cloud results directly for anomaly detection when the network condition is not ideal. By conducting comprehensive experiments on seven datasets, the experimental results demonstrate that our proposed AdaDiffAD always achieves lower time consumption while maintaining competitive anomaly detection performance compared to the state-of-the art without adaptive task offloading strategy.

Anomaly detection in multivariate time series has emerged as a critical challenge in the time series research community with significant application potentials in various scenarios, ranging from fault diagnosis to system state estimation in Industrial Control Systems (ICSs). Meanwhile, the demand for high availability and extensibility of ICSs necessitates their deployment in the JointCloud environment. Therefore, the performance of the multivariate time series anomaly detection model is expected to be enhanced in the JointCloud environment when encountering dynamic network conditions among multiple clouds. Impressed by the effectiveness of diffusion models in anomaly detection, we have chosen diffusion models for empowering our anomaly detection model. Specifically, we propose Progressively Distilled Diffusion Anomaly Detection model (ProDiffAD) in the JointCloud environment to seek for the balance between effectiveness and efficiency. Moreover, our proposed model is capable of being adaptive with the dynamic network conditions in the JointCloud environment by modeling the intercloud network conditions. To validate the effectiveness and efficiency of our model, comprehensive experiments are conducted on two real and five synthetic datasets. The experimental results demonstrate that our proposed model achieves more accurate and faster multivariate time series anomaly detection in the JointCloud environment under dynamic network conditions compared to state-of-the-art models.

Deepfake threatens the authenticity of the information in artificial intelligence Internet of Things (IoT) systems. Recently, several deepfake detection methods have been proposed in academia and industry for securing the authenticity of visual information in the face of artificial intelligence advances. Frame-level detection methods, a widely employed security method against deepfake, have a small model size and offer real-time responsiveness, despite basing their classification decision only on the information contained within the frame they are evaluating. We propose a new lightweight frame-level detection technique based on Bayesian inference weighting (BIW) to improve the robustness of existing frame-level detection models. Our proposed BIW technique employs the Naive Bayesian algorithm to estimate the reliability of any candidate model’s detection results. Comprehensive experiments were conducted on the attacked data sets by four designed video interference approaches and edge computing platform, showing that BIW enhances the robustness of all the baselines and improves their detection accuracy with a real-time response.

Limited data usually cause deep neural networks to hold poor performance after training, and many generative models are proposed to synthesize data to improve the performance of models. However, existing models ignore capturing the small defect details (e.g., features and locations), resulting in that most models cannot augment the Defect Location Sensitive Data (DLS data) in which the ratio of object size to the image size is small (e.g., 20%) and the locations of the defects are only on the object. In this paper, we propose a new augmentation model, named Defect Location Sensitive data augmentation GAN (DLS-GAN), to address DLS data augmentation problem. First, we modify the vanilla generator with two Encoder-Decoder models, and view the limited masked-images masked by labeling the defect-free pixels while remaining the defect pixels in defect images and many defect-free images as the input of the two models. The extracted feature map from the first Encoder-Decoder model provides the defect features and location information; the second one extracts the features of defect-free images, and integrates the two different features with a designed Defect Feature Transfer Module to synthesize images with desired defects. Second, we employ two discriminators to estimate the scores of both distribution matching degree and defect similarity between real data and generated ones. With the two modifications, we design a new loss function, and then prove that it makes our model get converged. Last, we conduct extensive experiments to demonstrate the significant performance improvement and generalizability of DLS-GAN on different types of DLS datasets. The experimental results show that our DLS-GAN outperforms the SOTA generative models in terms of synthesizing high quality images with desired defects.Note to Practitioners—Automated defect image detectors play an important role in the field of automated manufacturing. Training a detector with superior detection performance usually requires a large number of samples. However, it is difficult to collect many defect samples in practice. Although existing generative methods can synthesize realistic-like images, they cannot generate the Defect Location Sensitive Data (DLS Data) which refer to the samples that the defects appear at the specific locations in product objects, resulting in the synthesized images invalid. This paper proposes a new defect image generation model called DLS-GAN to address this problem, and validates its performance in different real-world industrial datasets ranging from DLS Data to Non-DLS Data. Such generated images can be adopted as useful resources for improving the detection performance of automated detector.

Popular ride-hailing products, such as DiDi, Uber and Lyft, provide people with transportation convenience. Pricing, order dispatching and vehicle repositioning are three tasks with tight correlation and complex interactions in ride-hailing platforms, significantly impacting each other’s decisions and demand distribution or supply distribution. However, no past work considered combining the three tasks to improve platform efficiency. In this paper, we exploit to optimize pricing, dispatching and repositioning strategies simultaneously. Such a new multi-stage decision-making problem is quite challenging because it involves complex coordination and lacks a unified problem model. To address this problem, we propose a novelJoint optimization framework ofPricing,Dispatching andRepositioning (JPDR) integrating contextual bandit and multi-agent deep reinforcement learning. JPDR consists of two components, including a Soft Actor-Critic (SAC)-based centralized policy for dispatching and repositioning and a pricing strategy learned by a multi-armed contextual bandit algorithm based on the feedback from the former. The two components learn in a mutually guided way to achieve joint optimization because their updates are highly interdependent. Based on real-world data, we implement a realistic environment simulator. Extensive experiments conducted on it show our method outperforms state-of-the-art baselines in terms of both gross merchandise volume and success rate.

Due to the contradiction between limited bandwidth and huge transmission parameters, federated Learning (FL) has been an ongoing challenge to reduce the model parameters that need to be transmitted to server in clients for fast transmission. Existing works that attempt to reduce the amount of transmitted parameters have limitations: 1) the reduced number of parameters is not significant; 2) the performance of the global model is limited. In this paper, we propose a novel method called Fed-KGF that significantly reduces the amount of model parameters while improving the global model performance. Our goal is to reduce those transmitted parameters by reducing the number of convolution kernels. Specifically, we construct an incomplete model with a few representative convolution kernels, and propose Kernel Generation Function (KGF) to generate other convolution kernels to render the incomplete model to be a complete one. We discard those generated kernels after training local models, and solely transmit those representative kernels during training, thereby significantly reducing the transmitted parameters. Furthermore, there is a client-drift in the traditional FL because of the averaging method, which hurts the global model performance. We innovatively select one or few modules from all client models in a permutation way, and only aggregate the uploaded modules rather than averaging all modules to reduce client-drift, thus improving the global model performance and further reducing the transmitted parameters. Experimental results on both non-Independent and Identically Distributed (non-IID) and IID scenarios for image classification and object detection tasks demonstrate that our Fed-KGF outperforms SOTA FL models.

Color-tone represents the prominent color of an image, and training generative adversarial nets (GAN) to change color-tones of generated images is desirable in many applications. Advances such as HistoGAN can manipulate color-tones of generated images with a target image. Yet, there are challenges. Kullback-Leibler (KL) divergence adopted by HistoGAN might bring the color-tone mismatching, because it is possible to provide infinite score to a generator. Moreover, only relying on distribution estimation also produces images with lower fidelity in HistoGAN. To address these issues, we propose a new approach, named dynamic weights GAN (DW-GAN). We use two discriminators to estimate the distribution matching degree and details' similarity, with Laplacian operator and Hinge loss. Laplacian operator can help capture more image details, while Hinge loss is deduced from mean difference (MD) that could avoid the case of infinite score. To synthesize desired images, we combine the loss of the two discriminators with generator loss and set the weights of the two estimated scores to be dynamic through the previous discriminators' outputs, given that the training signal of a generator is from a discriminator. Besides, we innovatively integrate the dynamic weights into other GAN variants (e.g., HistoGAN and StyleGAN) to show the improved performance. Finally, we conduct extensive experiments on one industrial Fabric and seven public datasets to demonstrate the significant performance of DW-GAN in producing higher fidelity images and achieving the lowest Frechet inception distance (FID) scores over SOTA baselines.

How to satisfy safety constraints almost surely (or with probability one) is becoming an emerging research issue for safe reinforcement learning (RL) algorithms in safety-critical domains. For instance, self-driving cars are expected to ensure that the driving strategy they adopt will never do harm to pedestrians and themselves. However, existing safe RL algorithms suffer from either risky and unstable constraint satisfaction or slow convergence. To tackle these two issues, we propose Conservatively Constrained Policy Optimization (CCPO) using state augmentation. CCPO designs a simple yet effective penalized reward function by introducing safety states and adaptive penalty factors under Safety Augmented MDP framework. Specifically, a novel Safety Promotion Function (SPF) is proposed to make the agent being more concentrated on constraint satisfaction with faster convergence by reshaping a more conservative constrained optimization objective. Moreover, we theoretically prove the convergence of CCPO. To validate both the effectiveness and efficiency of CCPO, comprehensive experiments are conducted in both single-constraint and more challenging multi-constraint environments. The experimental results demonstrate that the safe RL algorithms augmented by CCPO satisfy the predefined safety constraints almost surely and gain almost equivalent cumulative reward with faster convergence.

Enset (Ensete ventricosum (Welw.) Cheesman) is an indigenous Ethiopian crop that sustains the livelihood of more than 20 million people. Enset is used as a crop for human food security, animal feed, and a source of fiber for farmers. Since the past few decades, the production of enset has been severely curbed by bacterial wilt disease. The early detection and prevention of this disease are crucial for enhancing production. Deep learning in plant disease management is becoming an effective way to improve agro-productivity. However, standard convolutional neural network (CNN) models require a large number of parameters and higher computational costs. Efficient CNN models allow users to benefit without having to submit their data to a server for analysis, which is especially useful in parts of the world where internet access is fragile or even inaccessible. In this paper, we proposed a MobileNetV3-Small model which we jointly trained newly added classifier layers with selected final layers of the base model. The proposed model achieved 99.93% of accuracy rate on a test set. The model is trained using a dataset that includes 99 popular enset clones we collected from five different locations in Ethiopia with varying altitudes, climates, and weather conditions.

Multi-agent surrounding is a collaborative task that uses multiple agents to surround a stationary or moving target. Multi-agent surrounding has a wide range of applications, such as area monitoring of unmanned ships, environmental monitoring, and exploration of unknown environments. Existing work pay attention to the case of one-to-one surrounding of targets by agents, but there is a lack of consideration for the case where agents are not one-to-one with the target. In this paper, we propose the concept of virtual target, which is used as a mediator to realize the generic multi-agent surrounding a target. The main idea is to surround the actual target with the virtual target, while the agents surround the virtual target, where the generation of the virtual target is based on any given surrounding graph and random sampling, and the performance of the surrounding is ensured by the virtual target control algorithm and the agent controlling algorithm. The Lyapunov stability analysis and simulation results show that the proposed approach can make the virtual target fit the actual target effectively, and the agents can surround the actual target with the shape of the virtual target effectively.

Imbalanced data cause deep neural networks to output biased results, and it becomes more serious when facing extremely imbalanced data regarding the outliers with tiny size (the ratio of the outlier size to the image size is around 0.05%). Many data argumentation models are proposed to supplement imbalanced data to alleviate biased results. However, the existing augmentation models cannot synthesize tiny outliers, which make the generated data unavailable. In this article, we propose a new augmentation model named extremely imbalanced data augmentation generative adversarial nets (EID-GANs) to address the extremely imbalanced data augmentation problem. First, we design a new penalty function by subtracting the outliers from the cropped region of generated instance to guide the generator to learn the features of outliers. After this, we combine the output value of the penalty function with the generator loss to jointly update the generator’s parameters with backpropagation. Second, we propose a new evaluation approach that adopts two outlier detectors withk-fold cross-validation to assess the availability of generated instances. We conduct extensive experiments to demonstrate the significant performance improvement of EID-GAN on two extremely imbalanced datasets, which are the industrial Piston and the Fabric datasets, and one general imbalanced dataset, i.e., the public DAGM dataset. The experimental results show that our EID-GAN outperforms the state-of-the-art (SOTA) augmentation models on different imbalanced datasets.

The generative adversarial network (GAN) is usually built from the centralized, independent identically distributed (i.i.d.) training data to generate realistic-like instances. In real-world applications, however, the data may be distributed over multiple clients and hard to be gathered due to bandwidth, departmental coordination, or storage concerns. Although existing works, such as federated learning GAN (FL-GAN), adopt different distributed strategies to train GAN models, there are still limitations when data are distributed in a non-i.i.d. manner. These studies suffer from convergence difficulty, producing generated data with low quality. Fortunately, we found that these challenges are often due to the use of a federated averaging strategy to aggregate local GAN models' updates. In this article, we propose an alternative approach to tackling this problem, which learns a globally shared GAN model by aggregating locally trained generators' updates with maximum mean discrepancy (MMD). In this way, we term our approach improved FL-GAN (IFL-GAN). The MMD score helps each local GAN hold different weights, making the global GAN in IFL-GAN getting converged more rapidly than federated averaging. Extensive experiments on MNIST, CIFAR10, and SVHN datasets demonstrate the significant improvement of our IFL-GAN in both achieving the highest inception score and producing high-quality instances.

In the field of data mining, Time Series Classification (TSC) has attracted lots of interest from researchers due to its wide range of applications. Recently, deep learning models have shown promising performance on TSC by automatically extracting discriminative features from original time series. However, deep learning models are very time-consuming for training and lack interpretability. In the contrast, shapelets-based algorithms are easy to be implemented with interpretability preserved. In this paper, we proposed a salience-guided shapelets selection approach named Points2Shapelets, which inherits the advantages of both deep learning-based models and shapelets-based algorithms for TSC. Specifically, an interpretable and transparent shapelets selection approach is designed by leveraging the salience analysis of the pre-trained model. By conducting comprehensive experiments on 20 public UCR time series datasets, the experimental results demonstrate that our proposed approach Points2Shapelets achieves competitive performance shown by deep learning-based models. Meanwhile, explanations about how the salience analysis guides the decision-making of TSC models are offered in a visually understandable manner.

Reinforcement learning has been applied to various decision-making tasks and has achieved high profile successes. More and more studies have proposed to use reinforcement learning (RL) for traffic signal control to improve transportation efficiency. However, these methods suffer from a major exploration problem, and their performance is particularly poor. And even fail to quickly converge during the initial stage when interacting with the environment. To overcome this problem, we propose an RL model for traffic signal control based on demonstration data, which provides prior expert knowledge before RL model training. The demonstrations are collected from the classic method self-organizing traffic light (SOTL). It not only serves as expert knowledge but also explores and improves the entire decision-making system. Specifically, we use small demonstration data sets to pre-train the Ape-X Deep Q-learning Network (DQ N) for traffic signal control. When training a RL model from scratch, we often need a lot of data and time to learn a better initialization. Our approach is dedicated to making the RL algorithm converge quickly and accelerating the pace of learning. Extensive experiments on three urban datasets confirm that our method performs better with faster convergence and least travel time than the current RL-based methods by an average of 23.9%, 23.8%, 11.6%

Temporal knowledge graph (TKG) has received great attention in recent years. However, the TKG is not always complete due to the missing of important facts, which has seriously hindered its wide application. Inferring missing facts in TKG is a critical and challenging task due to its highly dynamic nature. Most of the existing methods mainly focus on modeling the structural features and temporal dependencies of TKG to solve the temporal knowledge graph completion problem (TKGC). However, those methods only operate at a single timescale without considering the latent time variability of TKG and thus limit the performance of TKGC solutions. Therefore, we propose a novel method named MtGCN (Multi-timescale history modeling framework based on Graph Convolutional Networks) for completing TKG by self-adaptively modeling the multi-timescale history of the incomplete TKG. Firstly, MtGCN uses a structural encoder with a graph convolutional network to mine the latent semantic information and structural features of the TKG. Secondly, MtGCN uses GRU-based temporal encoder to learn the historical information at various timescales of the TKG. Finally, it generates effective entity and relation representations to infer the missing facts for the originally incomplete TKG. By conducting comprehensive experiments on 5 public datasets, the experimental results show that our proposed method MtGCN significantly outperforms the baselines by achieving the highest MRR and HITS@1,3,10.

In recent years, radio frequency identification (RFID) based information query is widely used in many ap-plications. In order to meet various application requirements, different kinds of RFID protocols are proposed, such as ID collection, category estimation, and missing tag identification. We find that the structure and function used in these RFID protocols are quite similar. For example, empty slot skipping and collision slot reconciling are used in many protocols. An improvement in one protocol may also be applied in another protocol, or a combination of two compatible protocols can fulfill a new application requirement. However, currently there is no approach to measure the compatibility of two RFID protocols. In this study, we theoretically proposed the concept of RFID protocol compatibility and designed an approach to measure it. Analytic hierarchy process approach is revised for this purpose. The important features of an RFID protocol are identified, and then determine their weights according to their importance. The similarity of two protocols are computed by the weighted similarity of lowest level features. We validate this approach by using eight typical RFID protocols, and show useful information for the protocol design. For example, the results show the compatibility between CLS and SFMTI reaches 89.5 %, while the compatibility between CLS and TKQ is only 20.71 %, this conforms the characteristics of these protocols.

Federated learning, as a typical distributed learning paradigm, shows great potential in Industrial Internet of Things, Smart Home, Smart City, etc. It enables collaborative learning without data leaving local users. Despite the huge benefits, it still faces the risk of privacy breaches and a single point of failure for aggregation server. Adversaries can use intermediate models to infer user privacy, or even return incorrect global model by manipulating the aggregation server. To address these issues, several federated learning solutions focusing on privacy-preserving and security have been proposed. However, theses solutions still faces challenges in resource-limited scenarios. In this paper, we propose G-VCFL, a grouped verifiable chained privacy-preserving federated learning scheme. Specifically, we first use the grouped chain learning mechanism to guarantee the privacy of users, and then propose a verifiable secure aggregation protocol to guarantee the verifiability of the global model. G-VCFL does not require any complex cryptographic primitives and does not introduce noise, but enables verifiable privacy-preserving federated learning by utilizing lightweight pseudorandom generators. We conduct extensive experiments on real-world datasets by comparing G-VCFL with other state-of-the-art approaches. The experimental results and functional evaluation indicate that G-VCFL is efficient in the six experimental cases and satisfies all the intended design goals.

Probing techniques are widely used to identify faulty nodes in networks. Existing probe-based solutions for SDN fault localizationcan focus on two ways: per-rule and per-path. Both promote some certain switches to reporters by installing on them report rules. To avoid hindering other test packets, such report rules must vary between tests or be deleted before a next test, thus incurring excessive consumption on either TCAM resources of switches or bandwidth reserved for control messages. In this paper we present Voyager, a hybrid fault localization solution for SDN that fully combines the advantages of per-rule and per-path tests. Voyager significantly reduces the number of report rules and allows them to reside and function in switches persistently. With only one well-designed report rule for each switch installed, Voyager pinpoints faulty switches easily and tightly by sending test packets straight. Tests in Voyager are parallelizable and report rules are non-invasive. The performance evaluation on realistic datasets shows that Voyager is 24.0% to 92.3% faster than existing solutions.

Missing values appearing in multivariate time series often prevent further and in-depth analysis in real-world applications. To handle those missing values, advanced multivariate time series imputation methods are expected to (1) consider bi-directional temporal correlations, (2) model cross-variable correlations, and (3) approximate original data's distribution. However, most of existing approaches are not able to meet all the three above-mentioned requirements. Drawing on advances in machine learning, we propose BRNN-GAN, a generative adversarial network with bi-directional RNN cells. The BRNN cell is designed to model bi-directional temporal and cross-variable correlations, and the GAN architecture is employed to learn original data's distribution. By conducting comprehensive experiments on two public datasets, the experimental results show that our proposed BRNN-GAN outperforms all the baselines in terms of achieving the lowest Mean Absolute Error (MAE).

Time series classification (TSC) is widely used in various real-world applications such as human activity recognition, smart city governance, etc. Unfortunately, due to different reasons, only part of time series could be collected which may obviously degrade the performance of time series classifiers. To alleviate this problem, time series augmentation aims to generate synthetic time series by learning useful features from collected time series. As the popular generative model, generative adversarial networks (GAN) is regarded as a promising model for time series augmentation. However, applying GAN to the time series data suffers from a challenge in which the generated instances hold low quality but the model has gotten saturation. In this paper, for time series augmentation, we proposed TSA-GAN which is a robust GAN model with a self-adaptive recovering strategy to solve this problem. On 85 datasets of the UCR 2015 archive, our proposed TSA-GAN helps time series classifiers achieve performance improvements ranging from 8.3% to 12.5%, which is far better than the baseline.

Due to the dynamic characteristics of news and user preferences, personalized recommendation is a challenging problem. Traditional recommendation methods simply focus on current reward, which just recommend items to maximize the number of current clicks. And this may reduce users' interest in similar items. Although the news recommendation framework based on deep reinforcement learning preciously proposed (i.e, DRL, based on deep Q-learning) has the advantages of focusing on future total rewards and dynamic interactive recommendation, it has two issues. First, its exploration method is slow to converge, which may bring new users a bad experience. Second, it is hard to train on off-line data set because the reward is difficult to be determined. In order to address the aforementioned issues, we propose a framework named DEN-DQL for news recommendation based on deep Q-learning with double exploration networks. Also, we develop a new method to calculate rewards and use an off-line data set to simulate the online news clicking environment to train DEN-DQL. Then, the well trained DEN-DQL is tested in the online environment of the same data set, which demonstrates at least 10% improvement of the proposed DEN-DQL.

In recent years, Convolutional Neural Networks (CNN s) have been widely applied in various applications due to its powerful learning capability. However, its lack of explainability hinders its further usage in tasks requiring high reliability. Therefore, interpretability technique is the key to the application and deployment of CNN models. As a typical interpretability technique for CNN, Class Activation Map (CAM) utilizing the gradient based weights and activation map is widely applied to traditional CNN models for offering visual interpretability. However, the activation map adopted by CAM cannot loyally quantify the relevance between input samples and activation values. Hence, in this paper, we propose a new interpretability approach called Salience-CAM employing salience scores to accurately measure the relevance between input samples and activation values. To evaluate the effectiveness of Salience-CAM, comprehensive experiments are conducted on 6 selected time series datasets. By leveraging an evaluation algorithm proposed in this paper, the experimental results show that our proposed Salience-CAM outperforms the baseline by discovering more discriminative features.

As a typical task of time series mining, Time Series Classification (TSC) has attracted lots of attention from both researchers and domain experts due to its broad applications. To get rid of costly hand-crafting feature engineering process, deep learning techniques are applied for automatic feature extraction, which shows competitive or even better performance compared with state-of-the-art TSC solutions. However, on time series datasets presenting complex patterns, neither 1-Nearest-Neighbour classifier nor deep learning models are capable of achieving satisfactory classification accuracy which motivates us to explore new time series representations to help classifiers further improve the classification accuracy. In this paper, by building the binary distribution tree, an approach to time series classification based on deep learning models using new representations is proposed. By conducting comprehensive experiments over 6 most challenging time series datasets and comparing experimental results of the same classifier using the proposed representation or not, the potential of the proposed approach to enhancing time series classification accuracy is validated with a bunch of helpful findings.

With the advance of RFID technology and pervasive computing, a growing number of RFID devices are deployed in the surrounding environment and form large-scale RFID systems. Many applications run on top of such a system, and perform diverse and possibly conflicting data collection tasks. Existing works about RFID data collection either focus on deducing events of interest from primitive data, or scheduling the activation of readers to mitigate various of interference. The former ones assume that the primitive data have been collected already, and the later ones assume that all the readers belong to a single application whose objective is to read all the tags once. It lacks an effective way to specify the constraints in the process of data collection for multiple applications, and coordinate the readers to meet such requirements. In this paper, we proposed a specification language and a reader coordination algorithm to solve this problem. Our language can be used to specify complex constraints in data collection tasks, based on attribute selection, set relations, and temporal relations. And then a permission based data collection approach is developed for the readers to meet these constraints in a distributed way. Extensive simulation results show that the proposed approach outperforms existing approaches in terms of the execution time.

Interprocessor communication is an important factor in determining the performance scalability of parallel systems. The communication requirements of a parallel application can be quantified to understand its communication pattern and communication pattern similarities among applications can be determined. This is essential for the efficient mapping of applications on parallel systems and leads to better interprocessor communication implementation among others. This paper proposes a methodology to compare the communication pattern of distributed-memory programs. Communication correlation coefficient quantifies the degree of similarity between two applications based on the communication metrics selected to characterize the applications. To capture the network topology requirements, we extract the communication graph of each applications and quantities this similarity. We apply this methodology to four applications in the NAS parallel benchmark suite and evaluate the communication patterns by studying the effects of varying problem size and the number of logical processes (LPs).

Current trends in HPC (high performance computing) suggest that clusters will soon consist with hundreds, if not thousands, processors and the size of current scientific problems becomes much larger than before. Many researchers have predicted that the communication among these processors has dominated the execution time of the scientific parallel applications. Users will need well understanding on communication patterns among scientific parallel applications and their similarities so that users benefit not only from cost saving on constructing the running environment for these applications but also from obtaining better performance. In this paper, we address the communication pattern matching, and focus on point-to-point communication, which is primarily utilized (over 90% all MPI (message passing interface) calls) in most MPI codes and has much more impact on the communication performance than collective communication does. In this work, our contribution is that we propose a new approach MPACP (matching of parallel application communication patterns) to automate the analysis of the similarity between two parallel applications and provide a reliable report which will help users or developers understand the similarity among communication patterns of parallel applications. Furthermore, experimental results demonstrate the effective performance of our scheme in terms of the automatic matching of parallel application communication patterns.