Kaishun Wu

Shenzhen University · computer science and software engineering

Transformer architectures are popularized in both vision and natural language processing tasks, and they have achieved new performance benchmarks because of their long-term dependencies modeling, efficient parallel processing, and increased model capacity. While transformers offer powerful capabilities, their demanding computational requirements cl...

Continuous monitoring of nocturnal blood pressure is crucial for hypertension management and cardiovascular risk assessment. However, current clinical methods are invasive and discomforting, posing challenges. These traditional techniques often disrupt sleep, impacting patient compliance and measurement accuracy. Here we introduce a non-contact sys...

With the rise of mobile devices, bel canto practitioners increasingly utilize smart devices as auxiliary tools for improving their singing skills. However, they frequently encounter timbre abnormalities during practice, which, if left unaddressed, can potentially harm their vocal organs. Existing singing assessment systems primarily focus on pitch...

Acoustic-based human gesture recognition (HGR) applications have drawn increasing academic attention in order to overcome the shortcomings of conventional interaction methods on tiny devices. Existing techniques following a learning-based routine requires collecting massive application-specific training data. What is worse, the cross-domain problem...

This paper proposes a novel design on the wireless powered communication network (WPCN) in dynamic environments under the assistance of multiple unmanned aerial vehicles (UAVs). Unlike the existing studies, where the low-power wireless nodes (WNs) often conform to the coherent harvest-then-transmit protocol, under our newly proposed double-threshol...

Dynamic ridesharing has gained significant attention in recent years. However, existing ridesharing studies often focus on optimizing order dispatching and vehicle repositioning separately, leading to short-sighted decisions and underutilization of the ridesharing potential. In this paper, we propose a novel joint optimization framework called JODR...

With the increasing pervasiveness of smart earphones, it is appealing to propose more unobtrusive and convenient wearable authentication methods. Researchers have designed earphone-based authentication systems which utilize high-frequency audio signals to scan ear canal structure.Nevertheless, they possess shortcomings of low unobtrusiveness and ro...

Recent research studies have made significant progress in acoustic-based gesture recognition. However, existing methods lack the capability to expand to customized gestures and adapt to different practical environments. We propose a highly scalable gesture recognition system called EchoGest which integrates a well-designed feature-wise transformati...

Wireless sensing and communication evolved separately in the past. However, Integrated Sensing and Communication (ISAC) unlocks a new era of mobile network capabilities, with WiFi emerging as a prime candidate. By leveraging existing WiFi infrastructure and frequencies, ISAC enables powerful services like accurate localization and human activity re...

The next generation wireless networks demand full coverage from the sky to the deep ocean, in which the water-air cross-boundary communication is a critical component in a coordinated uncrewed vehicular network that connects both uncrewed aerial vehicles (UAVs) and autonomous underwater vehicles (AUVs). In such a network, optical wireless communica...

Federated learning (FL) offers distributed machine learning on edge devices. However, the FL model raises privacy concerns. Various techniques, such as homomorphic encryption (HE), differential privacy, and multiparty cooperation, are used to address the privacy issues of the FL model. Among them, HE ensures greater security and privacy since end-t...

Maritime data transmission with unmanned aerial vehicles (UAVs) in maritime Internet of Things (MIoT) systems has received increasing attention due to its flexibility and low cost. To further improve the efficiency of maritime data transmission between the UAVs and the maritime buoys, optical communication is considered as a promising technique bec...

Depression is a multifactorial disease with unknown etiology affecting globally. It’s the second most significant reason for infirmity in 2020, affecting about 50 million people worldwide, with 80% living in developing nations. Recently, a surge in depression research has been witnessed, resulting in a multitude of emerging techniques developed for...

Incorrect brushing methods normally lead to poor oral hygiene, and result in severe oral diseases and complications. While effective brushing can address this issue, individuals often struggle with incorrect brushing, like aggressive brushing, insufficient brushing, and missing brushing. To break this stalemate, in this paper, we proposed LiT, a to...

Acoustic-based human gesture recognition (HGR) offers diverse applications due to the ubiquity of sensors and touch-free interaction. However, existing machine learning approaches require substantial training data, making the process time-consuming, costly, and labor-intensive. Recent studies have explored cross-modal methods to reduce the need for...

Map matching aims to align GPS trajectories to their actual travel routes on a road network, which is an essential pre-processing task for most of trajectory-based applications. Many map matching approaches utilize Hidden Markov Model (HMM) as their backbones. Typically, HMM treats GPS samples of a trajectory as observations and nearby road segment...

The next-generation of wireless network 6G is envisioned to enable seamless global connectivity for Internet of everything (IoE) on the Earth. To this end, to implement high-speed wireless communication from the deep ocean to the sea surface leveraging multiple autonomous underwater vehicles (AUVs) with underwater wireless optical communication (UW...

The use of speakers in electronic devices has become widespread, but the security risks associated with micro-speakers, such as earphones, are often overlooked. Many assume that soundproof barriers can prevent sound leakage and protect privacy. This paper presents the prototype MagEar, an eavesdropping system that exploits magnetic side-channel sig...

Transforming physical surfaces into virtual interfaces can extend the interaction capability of many exciting metaverse applications in the future. Recent advances in vibration-based tap sensing show promise for this vision using passive vibration signals. However, current approaches based on Time-Difference-of-Arrival (TDoA) triangulation suffer t...

Underwater wireless optical communication (UWOC) has received widespread attention recently due to its distinct advantages in terms of high bandwidth, low power consumption, low delay and confidentiality. However, unlike underwater acoustic communication systems, it suffers from constraints, such as limited communication range and misalignment in o...

Cyber-attacks are becoming more common against Internet users due to the increasing dependency on online communication in their daily lives. X.509 Public-Key Infrastructure (PKIX) is the most widely adopted and used system to secure online communications and digital identities. However, different attack vectors exist against the PKIX system, which...

Unmanned aerial vehicles (UAVs) are a promising technology used to provide on-demand wireless energy transfer (WET) and sustain various low-power ground devices (GDs) for the Internet of Everything (IoE) in sixth generation (6G) wireless networks. However, an individual UAV has limited battery energy, which may confine the required wide-range mobil...

Achieving low-power wide coverage and good spectral efficiency is one of the main objectives of next-generation wireless communication. Non-Orthogonal Multiple Access (NOMA)-assisted Ambient Backscatter Communication (AmBC) has proven to be capable of offering great spectral efficiency at low power. In contrast, Intelligent Reflecting Surface (IRS)...

Human activity recognition (HAR) has become a research hotspot because of its wide range of application prospects. It has higher requirements for real-time and power-efficient processing. However, a large amount of data transfer between sensors and servers, and computation-intensive recognition models hinder the implementation of real-time HAR syst...

Clustering a big distributed dataset of hundred gigabytes or more is a challenging task in distributed computing. A popular method to tackle this problem is to use a random sample of the big dataset to compute an approximate result as an estimation of the true result computed from the entire dataset. In this paper, instead of using a single random...

Fall detection and recognition play a crucial role in enabling timely medical interventions for people who are at risk of falls, especially among vulnerable populations like older adults and those with mobility limitations. In this paper, a cost-effective integrated sensing and communication system, namely FallDR, is presented for fall detection an...

Backscatter Communication (BackCom) has opened up various novel joint sensing and communication applications in the Internet of things (IoT) domain. In particular, the IoT devices in water bodies have seen a recent paradigm shift toward more sustainability with the advent of Acoustic Backscatter Communication (A-BackCom). However, despite the low-p...

Clustering a big dataset without knowing the number of clusters presents a big challenge to many existing clustering algorithms. In this paper, we propose a Random Sample Partition-based Centers Ensemble (RSPCE) algorithm to identify the number of clusters in a big dataset. In this algorithm, a set of disjoint random samples is selected from the bi...

The increasingly remote workforce resulting from the global coronavirus pandemic has caused unprecedented cybersecurity concerns to organizations. Considerable evidence has shown that one-pass authentication fails to meet security needs when the workforce work from home. The recent advent of continuous authentication (CA) has shown the potential to...

In this chapter, we will introduce the cross-technology coexistence problem, and also the motivation of frequency-domain design to combat this problem and improve the network performance. We will then design and implement SledZig to boost cross-technology coexistence for ZigBee devices through both enabling more transmission opportunities and avoid...

In this chapter, we finally summarize this book and put forward several future research directions.KeywordsCross-technology interference managementCross-technology communication

The coexistence of heterogeneous devices in wireless networks brings a new topic on cross-technology communication (CTC) to improve the coexistence efficiency and boost collaboration among these devices. In this chapter, we will propose symbol-level energy modulation (SLEM) to achieve WiFi to ZigBee CTC transmission in commercial wireless devices....

In this chapter, we will present the motivation of signal identification for cross-technology coexistence, then elaborate our system design which contains two methods for signal identification. We will finally give performance evaluation for the two methods based on signals collected from hardware testbed.KeywordsSignal identificationFFTCNN

In this chapter, we will introduce the problem of cross-technology interference problem, and also the motivation of time-domain protocol design to combat this problem. We will then design E-CCA to improve the network performance with quantitative theoretical analysis, and finally evaluate its performance through simulations.KeywordsCross-technology...

Although voice authentication is generally secure, voiceprint-based authentication methods have the drawback of being affected by environmental noise, long passphrases, and large registered samples. Therefore, we present a breakthrough idea for smartphone user authentication by analyzing articulation and integrating the physiology and behavior of t...

Deep learning models have been widely studied and have achieved expert-level performance in medical imaging tasks such as diagnosis. Recent research also considers integrating data from various sources, for instance, chest X-rays (CXR) radiographs and electronic medical records (EMR), to further improve the performance. However, most existing metho...

Radar-based human activity recognition is attracting a wide range of interest from both industry and academia because of its through-wall ability, privacy-preserving capability, and device-free detection. Currently, most radar-based systems consider signal analysis and feature extraction in the frequency domain or the temporal domain independently...

Biochemical information sensing has always been one of the challenges in ubiquitous sensing research for mobile computing. Microorganisms will cause undetectable deterioration in drink production, such as wine and beverage, and microbial contamination is highly susceptible during storage like some liquors can be bottled for sometimes over ten years...

Generative adversarial networks as a powerful technique is also used in domain adaptation (DA) problem. Existing adversarial DA methods mainly conduct domain-wise alignment to alleviate marginal distribution shift between the two domains, while it may damage latent discriminative structure hidden in data feature space and cause negative transfer ac...

Numerous studies have extensively examined the living conditions of older adults who live alone, highlighting falls as the most significant threat to their well-being. Recognizing the critical importance of fall detection for older adults, researchers have conducted numerous investigations over the past decade to develop fall detection systems util...

With the rapid growth of Internet of Things, the number of heterogeneous wireless devices working in the same frequency band increases dramatically, leading to severe cross-technology interference. To enable coexistence, researchers have proposed a large number of mechanisms to manage interference. However, existing mechanisms have severe modificat...

Strengthening muscles can reduce body fat, increase lean muscle mass, maintain independence while aging, manage chronic conditions, and improve balance, reducing the risk of falling. The most critical factor inducing effectiveness in strength training is neuromuscular connection by adopting attentional focus during training. However, this is troubl...

Leveraging emerging edge computing and 5G networks, researchers proposed to offload the 3D rendering of interactive multimedia applications (e.g., virtual reality and cloud gaming) onto edge servers. For high resource utilization, multiple rendering tasks run in the same GPU server and compete against each other for the computation resource. Each t...

Limited by size, shape, and other factors, it is rather inconvenient to interact with new smart devices by traditional methods. Acoustic-based methods following a machine learning approach have been put forward to resolve this problem in previous works. But they possess limitations of heavy training overhead, low performance for unseen users, and i...

Handwritten signatures are widely used for identity authorization. However, verifying handwritten signatures is cumbersome in practice due to the dependency on extra drawing tools such as a digitizer, and because the false acceptance of a forged signature can cause damage to property. Therefore, exploring a way to balance the security and user expe...

Contactless authentication is crucial to keep social distance and prevent bacterial infection. However, existing authentication approaches, such as fingerprinting and face recognition, leverage sensors to verify static biometric features. They either increase the probability of indirect infection or inconvenience the users wearing masks. To tackle...

Wireless Sensing (WS) provides a low-cost means of monitoring humans and objects for the next generation of IoT. However, the deployment of WS for various applications is limited by; the heterogeneous nature of underlying technology in IoT devices, limited battery, and computational power of sensing devices. Backscatter Communication (BackCom) enab...

Computers are widely used for business and entertainment purposes throughout our modern lives. Computer kits provide a variety of services such as text processing, programming, shopping, and gaming. Computers have greatly enhanced the quality of our lives; however, we discover an often-overlooked fact that engaging in computer-related activities ma...

Reaching surrounding target objects is difficult for blind and low-vision (BLV) users, affecting their daily life. Based on interviews and exchanges, we propose an unobtrusive wearable system called LiSee to provide BLV users with all-day assistance. Following a user-centered design method, we carefully designed the LiSee prototype, which integrate...

Learning a foreign language pronunciation is the most challenging task for non-native speakers. Improving pronunciation based on feedback on pronunciation error scores is also not easy for learners. Our goal is to develop an alternative approach to pronunciation training that can point out articulation errors at the phoneme level to users through a...

The inevitable aging trend of the world’s population brings a lot of challenges to the health care for the elderly. For example, it is difficult to guarantee timely rescue for single-resided elders who fall at home. Under this circumstance, a reliable automatic fall detection machine is in great need for emergent rescue. However, the state-of-the-a...

Vehicular social networking is expected to become a reality soon, where secure and privacy-preserving identity management is a prerequisite. Various organizations and studies have recommended using Vehicular Public-key Infrastructure (VPKI) to securely and privately manage vehicles' identities. However, the existing VPKI schemes still do not deal w...

This paper presents a breakthrough framework for smartphone user authentication by analyzing the physiology and behavior of articulation, namely the vocal tract, tongue position, and lip movement, to expose individual uniqueness during uttering. The main idea is to leverage a smartphone's speaker and microphone to transmit and receive speech and ul...

Goal-oriented dialog policy learning algorithms aim to learn a dialog policy for selecting language actions based on the current dialog state. Deep reinforcement learning methods have been used for dialog policy learning. This work is motivated by the observation that, although dialog is a domain with rich contextual knowledge, reinforcement learni...

Federated learning (FL) is a new dawn of artificial intelligence (AI), in which machine learning models are constructed in a distributed manner while communicating only model parameters between a centralized aggregator and client internet-of-medical-things (IoMT) nodes. The performance of such a learning technique can be seriously hampered by the a...

Non-orthogonal multiple access (NOMA) has emerged as a promising technology for 5G networks and beyond. In order to fully reap the benefits of NOMA, it is essential to characterize its performance under different channel fading. In this paper, we carry out a performance analysis of the downlink NOMA-based dual-hop mixed powerline/wireless communica...

UAV-based mobile relay communication systems have an important position in future wireless networks, such as Beyond 5G and 6G, which provide ubiquitous network services. Along this line, UAV-based single-hop relay systems have numerous applications in emergency situations, such as data ferry and assisting post-disaster areas. Although there have be...

In an autonomous underwater vehicles– (AUVs–) based optical-acoustic hybrid network, it is critical to achieve ultra high-speed reliable communications, in order to reap the benefits of the complementary systems and perform high-bandwidth and low-latency operations. However, as the mobile AUVs operate in harsh oceanic environments, it is essential...

Click-through rate (CTR) prediction is a crucial task in recommender systems, which aims to model users’ dynamic preferences from their historical behaviors. To achieve this goal, most of the previous models adopt sequential neural networks (e.g., GRU) to encode the historical interactions into item representations for recommendations. Though these...

The next-generation of wireless network 6G is envisioned to achieve seamless global full coverage, and provide ultra-high-speed and extreme low delay network to connect the Internet of Everything (IoE) on the Earth. To this end, as the space-air-ground-underwater integrated network is a solid foundation of 6G, it is critical to develop reliable and...

Energy efficiency is an important criterion to judge the quality of mobile apps, but one third of our arbitrarily sampled apps suffer from energy issues that can quickly drain battery power. To understand these issues, we conduct an empirical study on 36 well-maintained apps such as Chrome and Firefox, whose issue tracking systems are publicly acce...

Underwater wireless optical communication (UWOC) has received widespread attention recently due to its advantages in terms of high bandwidth, low power consumption and low delay. However, unlike underwater acoustic communication systems, the underwater wireless optical communication system is limited by its short communication range. In order to en...

p>In this work, a non-orthogonal multiple access NOMA) relying on a two-way relaying (TWR) approach is investigated to promote more efficient use of the available spectrum. Specifically, a NOMA-enabled half-duplex decode-and-forward relay node is used to simultaneously exchange data between two cellular users and a base station (BS), while assuming...

Unmanned Aerial Vehicles (UAVs) are one of the effective means to provide emergency communication services in post-disaster areas. In this paper, we consider data dissemination in post-disaster areas, where all IoT nodes may not have data needs all the time. The energy consumption in data dissemination is one of the key metrics to pay attention to...

In this work, a non-orthogonal multiple access NOMA) relying on a two-way relaying (TWR) approach is investigated to promote more efficient use of the available spectrum. Specifically, a NOMA-enabled half-duplex decode-and-forward relay node is use