OpenRaiser/Intern-Atlas huggingface dataset:
Chameleons on Cloudlets: Elastic Edge Computing Through Microservice Variants
Venue: arXiv cs.DC 2021
Year: 2021

Common deployment models for Edge Computing are based on (composable) microservices that are offloaded to cloudlets. Runtime adaptations-in response to varying load, QoS fulfillment, mobility, etc.-are typically based on coarse-grained and costly management operations such as resource re-allocation or migration. The services themselves, however, remain non-adaptive, worsening the already limited elasticity of Edge Computing compared to Cloud Computing. Edge computing applications often have stringent requirements on the execution time but are flexible regarding the quality of a computation. The potential benefits of exploiting this trade-off remain untapped. This paper introduces the concept of adaptable microservices that provide alternative variants of specific functionalities. We define so-called service variants that differ w.r.t. the internal functioning of the service, manifested in different algorithms, parameters, and auxiliary data they use. Such variants allow fine-grained trade-offs between the QoS (e.g., a maximum tolerable execution time) and the quality of the computation. We integrate adaptable microservices into an Edge Computing framework, show the practical impact of service variants, and present a strategy for switching variants at runtime.
High Fidelity Fingerprint Generation: Quality, Uniqueness, and Privacy
Venue: arXiv cs.CV 2021
Year: 2021

In this work, we utilize progressive growth-based Generative Adversarial Networks (GANs) to develop the Clarkson Fingerprint Generator (CFG). We demonstrate that the CFG is capable of generating realistic, high fidelity, $512\times512$ pixels, full, plain impression fingerprints. Our results suggest that the fingerprints generated by the CFG are unique, diverse, and resemble the training dataset in terms of minutiae configuration and quality, while not revealing the underlying identities of the training data. We make the pre-trained CFG model and the synthetically generated dataset publicly available at https://github.com/keivanB/Clarkson_Finger_Gen
Survey on Energy-Efficient Techniques for Wireless Sensor Networks
Venue: arXiv cs.NI 2021
Year: 2021

The concept of energy-efficient computing is not new but recently the focus of the industries related to technology has been shifted towards energy utilization techniques with minimum energy loss. Computer Networks also needed to be energy efficient. Energy Consumption is also an important challenge in the Wireless Sensor network. Energy efficiency can be achieved with the help of clustering algorithms, energy-efficient routing methods, improved data aggregation schemes, and energy-efficient MAC protocols for WSN.
Sheaves as a Framework for Understanding and Interpreting Model Fit
Venue: arXiv cs.LG 2021
Year: 2021

As data grows in size and complexity, finding frameworks which aid in interpretation and analysis has become critical. This is particularly true when data comes from complex systems where extensive structure is available, but must be drawn from peripheral sources. In this paper we argue that in such situations, sheaves can provide a natural framework to analyze how well a statistical model fits at the local level (that is, on subsets of related datapoints) vs the global level (on all the data). The sheaf-based approach that we propose is suitably general enough to be useful in a range of applications, from analyzing sensor networks to understanding the feature space of a deep learning model.
Low-Memory Implementations of Ridge Solutions for Broad Learning System with Incremental Learning
Venue: arXiv cs.LG 2021
Year: 2021

The existing low-memory BLS implementation proposed recently avoids the need for storing and inverting large matrices, to achieve efficient usage of memories. However, the existing low-memory BLS implementation sacrifices the testing accuracy as a price for efficient usage of memories, since it can no longer obtain the generalized inverse or ridge solution for the output weights during incremental learning, and it cannot work under the very small ridge parameter that is utilized in the original BLS. Accordingly, it is required to develop the low-memory BLS implementations, which can work under very small ridge parameters and compute the generalized inverse or ridge solution for the output weights in the process of incremental learning. In this paper, firstly we propose the low-memory implementations for the recently proposed recursive and square-root BLS algorithms on added inputs and the recently proposed squareroot BLS algorithm on added nodes, by simply processing a batch of inputs or nodes in each recursion. Since the recursive BLS implementation includes the recursive updates of the inverse matrix that may introduce numerical instabilities after a large number of iterations, and needs the extra computational load to decompose the inverse matrix into the Cholesky factor when cooperating with the proposed low-memory implementation of the square-root BLS algorithm on added nodes, we only improve the low-memory implementations of the square-root BLS algorithms on added inputs and nodes, to propose the full lowmemory implementation of the square-root BLS algorithm. All the proposed low-memory BLS implementations compute the ridge solution for the output weights in the process of incremental learning, and most of them can work under very small ridge parameters.
SCSGuard: Deep Scam Detection for Ethereum Smart Contracts
Venue: arXiv cs.CR 2021
Year: 2021

Smart contract is the building block of blockchain systems that enables automated peer-to-peer transactions and decentralized services. With the increasing popularity of smart contracts, blockchain systems, in particular Ethereum, have been the "paradise" of versatile fraud activities in which Ponzi, Honeypot and Phishing are the prominent ones. Formal verification and symbolic analysis have been employed to combat these destructive scams by analyzing the codes and function calls, yet the vulnerability of each \emph{individual} scam should be predefined discreetly. In this work, we present SCSGuard, a novel deep learning scam detection framework that harnesses the automatically extractable bytecodes of smart contracts as their new features. We design a GRU network with attention mechanism to learn from the \emph{N-gram bytecode} patterns, and determines whether a smart contract is fraudulent or not. Our framework is advantageous over the baseline algorithms in three aspects. Firstly, SCSGuard provides a unified solution to different scam genres, thus relieving the need of code analysis skills. Secondly, the inference of SCSGuard is faster than the code analysis by several order of magnitudes. Thirdly, experimental results manifest that SCSGuard achieves high accuracy (0.92$\sim$0.94), precision (0.94$\sim$0.96\%) and recall (0.97$\sim$0.98) for both Ponzi and Honeypot scams under similar settings, and is potentially useful to detect new Phishing smart contracts.
ReduNet: A White-box Deep Network from the Principle of Maximizing Rate Reduction
Venue: arXiv cs.LG 2021
Year: 2021

This work attempts to provide a plausible theoretical framework that aims to interpret modern deep (convolutional) networks from the principles of data compression and discriminative representation. We argue that for high-dimensional multi-class data, the optimal linear discriminative representation maximizes the coding rate difference between the whole dataset and the average of all the subsets. We show that the basic iterative gradient ascent scheme for optimizing the rate reduction objective naturally leads to a multi-layer deep network, named ReduNet, which shares common characteristics of modern deep networks. The deep layered architectures, linear and nonlinear operators, and even parameters of the network are all explicitly constructed layer-by-layer via forward propagation, although they are amenable to fine-tuning via back propagation. All components of so-obtained "white-box" network have precise optimization, statistical, and geometric interpretation. Moreover, all linear operators of the so-derived network naturally become multi-channel convolutions when we enforce classification to be rigorously shift-invariant. The derivation in the invariant setting suggests a trade-off between sparsity and invariance, and also indicates that such a deep convolution network is significantly more efficient to construct and learn in the spectral domain. Our preliminary simulations and experiments clearly verify the effectiveness of both the rate reduction objective and the associated ReduNet. All code and data are available at \url{https://github.com/Ma-Lab-Berkeley}.
HyFed: A Hybrid Federated Framework for Privacy-preserving Machine Learning
Venue: arXiv cs.LG 2021
Year: 2021

Federated learning (FL) enables multiple clients to jointly train a global model under the coordination of a central server. Although FL is a privacy-aware paradigm, where raw data sharing is not required, recent studies have shown that FL might leak the private data of a client through the model parameters shared with the server or the other clients. In this paper, we present the HyFed framework, which enhances the privacy of FL while preserving the utility of the global model. HyFed provides developers with a generic API to develop federated, privacy-preserving algorithms. HyFed supports both simulation and federated operation modes and its source code is publicly available at https://github.com/tum-aimed/hyfed.
Deterministic Size Discovery and Topology Recognition in Radio Networks with Short Labels
Venue: arXiv cs.DS 2021
Year: 2021

We consider the fundamental problems of size discovery and topology recognition in radio networks modeled by simple undirected connected graphs. Size discovery calls for all nodes to output the number of nodes in the graph, called its size, and in the task of topology recognition each node has to learn the topology of the graph and its position in it. In radio networks, nodes communicate in synchronous rounds and start in the same round. In each round a node can either transmit the same message to all its neighbors, or stay silent and listen. At the receiving end, a node $v$ hears a message from a neighbor $w$ in a given round, if $v$ listens in this round, and if $w$ is its only neighbor that transmits in this round. If more than one neighbor of a node $v$ transmits in a given round, there is a collision at $v$. We do not assume collision detection: in case of a collision, node $v$ does not hear anything. The time of a deterministic algorithm for each of the above problems is the worst-case number of rounds it takes to solve it. Our goal is to construct short labeling schemes for size discovery and topology recognition in arbitrary radio networks, and to design efficient deterministic algorithms using these schemes. For size discovery, we construct a labeling scheme of length $O(\log\logΔ)$ and we design an algorithm for this problem using this scheme and working in time $O(\log^2 n)$, where $n$ is the size of the graph. We also show that time complexity $O(\log^2 n)$ is optimal for the problem of size discovery, whenever the labeling scheme is of optimal length. For topology recognition, we construct a labeling scheme of length $O(\logΔ)$, and we design an algorithm for this problem using this scheme working in time $O\left(DΔ+\min(Δ^2,n)\right)$. We also show that the length of our labeling scheme is asymptotically optimal.
Support Optimality and Adaptive Cuckoo Filters
Venue: arXiv cs.DS 2021
Year: 2021

Filters (such as Bloom Filters) are data structures that speed up network routing and measurement operations by storing a compressed representation of a set. Filters are space efficient, but can make bounded one-sided errors: with tunable probability epsilon, they may report that a query element is stored in the filter when it is not. This is called a false positive. Recent research has focused on designing methods for dynamically adapting filters to false positives, reducing the number of false positives when some elements are queried repeatedly. Ideally, an adaptive filter would incur a false positive with bounded probability epsilon for each new query element, and would incur o(epsilon) total false positives over all repeated queries to that element. We call such a filter support optimal. In this paper we design a new Adaptive Cuckoo Filter and show that it is support optimal (up to additive logarithmic terms) over any n queries when storing a set of size n. Our filter is simple: fixing previous false positives requires a simple cuckoo operation, and the filter does not need to store any additional metadata. This data structure is the first practical data structure that is support optimal, and the first filter that does not require additional space to fix false positives. We complement these bounds with experiments showing that our data structure is effective at fixing false positives on network traces, outperforming previous Adaptive Cuckoo Filters. Finally, we investigate adversarial adaptivity, a stronger notion of adaptivity in which an adaptive adversary repeatedly queries the filter, using the result of previous queries to drive the false positive rate as high as possible. We prove a lower bound showing that a broad family of filters, including all known Adaptive Cuckoo Filters, can be forced by such an adversary to incur a large number of false positives.
Searching Collaborative Agents for Multi-plane Localization in 3D Ultrasound
Venue: arXiv cs.CV 2021
Year: 2021

3D ultrasound (US) has become prevalent due to its rich spatial and diagnostic information not contained in 2D US. Moreover, 3D US can contain multiple standard planes (SPs) in one shot. Thus, automatically localizing SPs in 3D US has the potential to improve user-independence and scanning-efficiency. However, manual SP localization in 3D US is challenging because of the low image quality, huge search space and large anatomical variability. In this work, we propose a novel multi-agent reinforcement learning (MARL) framework to simultaneously localize multiple SPs in 3D US. Our contribution is four-fold. First, our proposed method is general and it can accurately localize multiple SPs in different challenging US datasets. Second, we equip the MARL system with a recurrent neural network (RNN) based collaborative module, which can strengthen the communication among agents and learn the spatial relationship among planes effectively. Third, we explore to adopt the neural architecture search (NAS) to automatically design the network architecture of both the agents and the collaborative module. Last, we believe we are the first to realize automatic SP localization in pelvic US volumes, and note that our approach can handle both normal and abnormal uterus cases. Extensively validated on two challenging datasets of the uterus and fetal brain, our proposed method achieves the average localization accuracy of 7.03 degrees/1.59mm and 9.75 degrees/1.19mm. Experimental results show that our light-weight MARL model has higher accuracy than state-of-the-art methods.
Revisiting Knowledge Distillation for Object Detection
Venue: arXiv cs.CV 2021
Year: 2021

The existing solutions for object detection distillation rely on the availability of both a teacher model and ground-truth labels. We propose a new perspective to relax this constraint. In our framework, a student is first trained with pseudo labels generated by the teacher, and then fine-tuned using labeled data, if any available. Extensive experiments demonstrate improvements over existing object detection distillation algorithms. In addition, decoupling the teacher and ground-truth distillation in this framework provides interesting properties such: as 1) using unlabeled data to further improve the student's performance, 2) combining multiple teacher models of different architectures, even with different object categories, and 3) reducing the need for labeled data (with only 20% of COCO labels, this method achieves the same performance as the model trained on the entire set of labels). Furthermore, a by-product of this approach is the potential usage for domain adaptation. We verify these properties through extensive experiments.
A Robust and Generalized Framework for Adversarial Graph Embedding
Venue: arXiv cs.LG 2021
Year: 2021

Graph embedding is essential for graph mining tasks. With the prevalence of graph data in real-world applications, many methods have been proposed in recent years to learn high-quality graph embedding vectors various types of graphs. However, most existing methods usually randomly select the negative samples from the original graph to enhance the training data without considering the noise. In addition, most of these methods only focus on the explicit graph structures and cannot fully capture complex semantics of edges such as various relationships or asymmetry. In order to address these issues, we propose a robust and generalized framework for adversarial graph embedding based on generative adversarial networks. Inspired by generative adversarial network, we propose a robust and generalized framework for adversarial graph embedding, named AGE. AGE generates the fake neighbor nodes as the enhanced negative samples from the implicit distribution, and enables the discriminator and generator to jointly learn each node's robust and generalized representation. Based on this framework, we propose three models to handle three types of graph data and derive the corresponding optimization algorithms, i.e., UG-AGE and DG-AGE for undirected and directed homogeneous graphs, respectively, and HIN-AGE for heterogeneous information networks. Extensive experiments show that our methods consistently and significantly outperform existing state-of-the-art methods across multiple graph mining tasks, including link prediction, node classification, and graph reconstruction.
Video-based Person Re-identification without Bells and Whistles
Venue: arXiv cs.CV 2021
Year: 2021

Video-based person re-identification (Re-ID) aims at matching the video tracklets with cropped video frames for identifying the pedestrians under different cameras. However, there exists severe spatial and temporal misalignment for those cropped tracklets due to the imperfect detection and tracking results generated with obsolete methods. To address this issue, we present a simple re-Detect and Link (DL) module which can effectively reduce those unexpected noise through applying the deep learning-based detection and tracking on the cropped tracklets. Furthermore, we introduce an improved model called Coarse-to-Fine Axial-Attention Network (CF-AAN). Based on the typical Non-local Network, we replace the non-local module with three 1-D position-sensitive axial attentions, in addition to our proposed coarse-to-fine structure. With the developed CF-AAN, compared to the original non-local operation, we can not only significantly reduce the computation cost but also obtain the state-of-the-art performance (91.3% in rank-1 and 86.5% in mAP) on the large-scale MARS dataset. Meanwhile, by simply adopting our DL module for data alignment, to our surprise, several baseline models can achieve better or comparable results with the current state-of-the-arts. Besides, we discover the errors not only for the identity labels of tracklets but also for the evaluation protocol for the test data of MARS. We hope that our work can help the community for the further development of invariant representation without the hassle of the spatial and temporal alignment and dataset noise. The code, corrected labels, evaluation protocol, and the aligned data will be available at https://github.com/jackie840129/CF-AAN.
Automated Knee X-ray Report Generation
Venue: arXiv cs.CV 2021
Year: 2021

Gathering manually annotated images for the purpose of training a predictive model is far more challenging in the medical domain than for natural images as it requires the expertise of qualified radiologists. We therefore propose to take advantage of past radiological exams (specifically, knee X-ray examinations) and formulate a framework capable of learning the correspondence between the images and reports, and hence be capable of generating diagnostic reports for a given X-ray examination consisting of an arbitrary number of image views. We demonstrate how aggregating the image features of individual exams and using them as conditional inputs when training a language generation model results in auto-generated exam reports that correlate well with radiologist-generated reports.
The Efficacy of a Virtual Reality-Based Mindfulness Intervention
Venue: arXiv cs.HC 2021
Year: 2021

Mindfulness can be defined as increased awareness of and sustained attentiveness to the present moment. Recently, there has been a growing interest in the applications of mindfulness for empirical research in wellbeing and the use of virtual reality (VR) environments and 3D interfaces as a conduit for mindfulness training. Accordingly, the current experiment investigated whether a brief VR-based mindfulness intervention could induce a greater level of state mindfulness, when compared to an audio-based intervention and control group. Results indicated two mindfulness interventions, VR-based and audio-based, induced a greater state of mindfulness, compared to the control group. Participants in the VR-based mindfulness intervention group reported a greater state of mindfulness than those in the guided audio group, indicating the immersive mindfulness intervention was more robust. Collectively, these results provide empirical support for the efficaciousness of a brief VR-based mindfulness intervention in inducing a robust state of mindfulness in laboratory settings.
Distancing interfaces -- improvisational media architectures for place-based discourse under lockdown
Venue: arXiv cs.HC 2021
Year: 2021

The paper presents the case study of BERLIN_LOKAL_ZEIT, a collaborative archive and exhibition project aiming to document and reflect individual experiences of the COVID-19 lockdowns in Berlin, Germany. What began as an observational effort in spring 2020became a year-long archive, exhibition, and broadcasting platform that generated various hyper-local interfaces. The paper articulates an improvisational approach to media architecture in the form of self-reflection by the project initiators. Necessitated by the limitations imposed by the lockdowns on cultural production and public discourse, the paper presents an alternative conceptual approach to media architecture that is not based on a fully-specified technological infrastructure for discourse and interaction but instead on improvisational practices that manifest themselves in different technical interfaces. This improvisational approach is not merely a mode of production, but raises questions of about the discourse of media architecture and its underlying assumptions of methodological rigor. In traditional HCI, systems and artifacts are often presented as stable and fully specified, while their users are considered interchangeable. In contrast, we consider urban media interfaces as improvisation-driven infrastructures (or improstructures) in which the actors and their relationships are stable, while the technologies they create are provisional and in flux. As a consequence, the defining property of media architecture is no longer the structural integration of media into architecture but the embodiment of mediated communication in objects and performances at concrete places. In an environment where many physical spaces are longer accessible and human contact among strangers diminished, the project explores the restorative function and capacities of media architecture for shared reflection and discourse in physical public space.