Dagang Li

Macau University of Science and Technology | MUST

With the benefits of compact size and cost effectiveness, the solid-state LiDAR (SSL) has emerged as the preferred choice for the mass-produced vehicles with advanced driver assistance systems (ADAS). To ensure precise and dependable mapping for ADAS, it is essential to accurately fuse LiDAR and inertial measurements through precise extrinsic calib...

Network slicing is an advanced technology that significantly enhances network flexibility and efficiency. Recently, reinforcement learning (RL) has been applied to solve resource management challenges in 6G networks. However, RL-based network slicing solutions have not been widely adopted. One of the primary reasons for this is the slow convergence...

In the field of autonomous driving, the perception of the environment plays a crucial role, serving as a fundamental component. Accurate and precise environmental detection is vital in providing detailed information about obstacles for the control module of autonomous vehicles. MEMS LiDAR, as a prevalent sensor for acquiring obstacle positions, off...

To improve the robustness and effectiveness for detecting free parking spaces, we propose a LiDAR-based parking sensing system, which contains multi-modules, i.e., perception, free space parking lots’ construction, parking space tracking and obstacle detection. Comprehensive experiments demonstrate that our LiDAR-based parking sensing system can no...

Dust devil is an important part of the Martian climate system, which can help us better understand scientific questions of the climate, surface-atmosphere interactions, aeolian processes, and regolith on Mars. Therefore, automatic detection of dust devils from Mars Orbiter images is becoming increasingly important for the scientific study and the p...

The intelligent edge has accelerated the Internet of Things (IoT) revolution towards next-generation operational efficiency and massive connectivity. Supporting fast response, agility, and adaptive industrial IoT (IIoT) services, on the other hand, remains a challenge. In this paper, we investigate the dynamic service function chain (SFC) orchestra...

Efficiency of Battery Energy Storage Systems (BESSs) is increasingly critical as renewable energy generation becomes more prevalent on the grid. Therefore, it is necessary to study the energy efficiency of Lithium-ion Batteries (LIBs), which are typically used in BESSs. The purpose of this study is to propose the State of Efficiency (SOE) as a meas...

The parallel processing of the service function chain (SFC) is expected to provide better low-delay service delivery, because it breaks through the bottleneck of traditional serial processing mode in which service delay increases linearly with the SFC length. However, the provision of parallelized SFC (PSFC) is much more difficult due to the unique...

We study the graph representation learning problem that has emerged with the advent of numerous graph analysis tasks in the recent past. The task of representation learning from graphs of heterogeneous object attributes and complex topological structures is important yet challenging in practice. We propose an Attribute-interactive Neighborhood-aggr...

Knowledge graphs (KGs) store real-world information in the form of graphs consisting of relationships between entities and have been widely used in the Semantic Web community since it is readable by machines. However, most KGs are known to be very incomplete. The issues of structure sparseness and noise paths in large-scale KGs create a substantial...

With the rapid development of deep learning, more researchers have attempted to apply nonlinear learning methods such as recurrent neural networks (RNNs) and attention mechanisms to capture the complex patterns hidden in stock market trends. Most existing approaches to this task employ an attention mechanism that primarily relies on the information...

Stock index prediction aims to predict the future price of stock indexes, which plays a key role in seeking the maximum profit from stock investment. However, It has been proven to be a very difficult task because of its innate complexity, dynamics, and uncertainty. With the rapid development of deep learning, more researchers have attempted to app...

Stock performance prediction plays an important role in determining the appropriate timing of buying or selling a stock in the development of a trading system. However, precise stock price prediction is challenging because of the complexity of the internal structure of the stock price system and the diversity of external factors. Although research...

This paper focuses on the use of embedding with global semantic relations to improve the cross modal retrieval. Our method smoothly bridges the heterogeneity gap by graph embedding and then obtains discriminative representation by supervised learning. First, we construct a semantic correlation graph based on the intra-modal similarity and the seman...

Software switches are being deployed in SDN to enable a wide spectrum of non-traditional applications. The popular Open vSwitch uses a variant of Tuple Space Search (TSS) for packet classifications. Although it has good performance on rule updates, it is less efficient than decision trees on lookups. In this paper, we propose a two-stage framework...

Graph partitioning plays a very fundamental and important role in a distributed graph computing (DGC) framework, because it determines the communication cost and workload balance among computing nodes. Existing solutions are mainly heuristic-based but unfortunately cannot achieve partitioning quality, load balance, and speed at the same time. In th...

With the growing scale of big data, probabilistic structures receive increasing popularity for efficient approximate storage and query processing. For example, Bloom filters (BF) can achieve satisfactory performance for approximate membership existence query at the expense of false positives. However, a standard Bloom filter can only handle univari...

The Basic Counting problem [1] is one of the most fundamental and critical streaming problems of sliding window queries over data streams. Given a stream of 0's and 1's, the purpose of this problem is to estimate the number of 1's in the last N elements (or time units) seen from the stream. Its solution can be used as building blocks to solve numer...

High-performance packet classification algorithms have been widely studied during the past decade. Bit-Vector-based algorithms proposed for FPGA can achieve very high throughput by decomposing rules delicately. However, the relatively large memory resources consumption severely hinders applications of the algorithms extensively. It is noteworthy th...

Ternary Content Addressable Memory (TCAM) is widely used for designing high-throughput forwarding engines on most of today's high-end routers. Despite its capability for line-speed queries, it is very power hungry and space inefficient. By making use of a pre-classifier to activate TCAM blocks selectively, MEET-IP, a recently proposed TCAM based IP...

Multi-field packet classification is not only an indispensable and challenging functionality of existing network devices, but it also appears as flow tables lying at the heart of the forwarding plane of software defined networking age. Despite almost two decades of research, algorithmic solutions still fall short of meeting the line-speed of high-p...

In this letter we propose Meta-key, a data-sharing mechanism that enables users share their encrypted data under a blockchain-based decentralized storage architecture. All the data-encryption keys are encrypted by the owner’s public key and put onto the blockchain for safe and secure storage and easy key-management. Encrypted data are stored in ded...

Virtual Machine (VM) live migration is a crucial practice commonly applied in data centers, which can help users and enterprises manage network services more flexibly and economically. In general, large enterprises always require uninterrupted network service in VM migration, but the VM’s own behavior and limited link resources often result in incr...

Under some applications, identity-authentication must be involved into block-chain systems. However, the introduction of traditional PKI mechanism in block-chain systems is not proper for 3 reasons: (1) a centralized certification authority (CA) represents a single point of failure in the network; (2) the numbers and locations of nodes vary in time...

Sketch is a probabilistic data structure designed for the estimation of item frequencies in a multiset, which is extensively used in data stream processing. The key metrics of sketches for data streams are accuracy, speed, and memory usage. There are various sketches in the literature, but most of them cannot achieve high accuracy, high speed and u...

Most of today’s intelligent video surveillance systems are based on Linux core and rely on the kernel’s socket mechanism for data transportation. In this paper, we propose APRO, a novel framework with optimized zero-copy capability customized for video surveillance networks. Without the help of special hardware support such as RNIC or NetFPGA, the...

Repairing locality is an appreciated feature for distributed storage, in which a damaged or lost data share can be repaired by accessing a subset of other shares much smaller than is required for decoding the complete data. However for Secret Sharing (SS) schemes, it has been proven theoretically that local repairing can not be achieved with perfec...

Hash table is used in many areas of networking such as route lookup, packet classification, per-flow state management and network monitoring for its constant access time latency at moderate loads. However, collisions may become frequent at high loads in traditional hash tables, which may lead the access time complexity to be linear and intolerable...

While receiving a certain packet with unknown destination, a router either simply drops it or sends queries around as a remedy. Dropping it sacrifices transmission stability, but sending queries may cause too much overload. Such situation can be seen more frequently in Information-Centric Networking (ICN) since it has a larger namespace for routing...

Due to the explosive growth of multimedia content (especially videos) over the Internet, content-centric networking (CCN) is proposed to remit the problems of modern bandwidth-intensive Internet usage patterns. Additionally, the current streaming media coding is designed for video service for IP networks. However, there are few researches who conce...

Content-Centric Networking (CCN) is a new networking paradigm to resolve the data traffic explosive problem of the Internet caused by a rapid increase in file sharing and video streaming traffic. Instead of seeking a single best path in the IP network, CCN is able to employ multipath to deliver packets. The conventionally adopted CCN forwarding str...

As distributed storage clusters have been used more and more widely in recent years, data replication management has become a hot research topic. In storage clusters, internal network bandwidth is usually a scarce resource. Misplaced replicas may take up too much network bandwidth and greatly deteriorate the overall performance of the cluster. Base...

Recent studies on switching fabrics mainly focus on the switching schedule algorithms, which aim at improving the throughput (a key performance metric). However, the delay (another key performance metric) of switching fabrics cannot be well guaranteed. A good switching fabric should be endowed with the properties of high throughput, delay guarantee...

Identity centric networks (IdCN), in which packets are destined to user identities, is one of the future network architectures under discussion. Since user mobility is already widely observed in the current Internet and seen as one of the main features of the future Internet, seamless mobility needs to be kept in mind for whatever routing mechanism...

Cost computation, cost aggregation, disparity optimization, and disparity refinement are the four main steps for stereo matching. While the first three steps have been widely investigated, few efforts have been taken on disparity refinement. In this paper, we propose a color image-guided disparity refinement method to further remove the boundary-in...

As distributed storage clusters have been used more and more widely in recent years, data replication management, which is the key to data availability, has become a hot research topic. In storage clusters, internal network bandwidth is usually a scarce resource. Misplaced replicas may take up too much network bandwidth and greatly deteriorate the...

Flat Routing (FR) is a routing technique that routes packet according to a globally unique flat identity. Compared with traditional IP based routing, flat routing decouples host with its location, which provides built-in mobility support and eases network management. Besides, flat routing is also considered as a building block for next generation n...

The next generation of mobile communication systems will be an integration of complementary wired and wireless network technologies. A mobile user equipped with multiple interfaces that support different technologies should be able to switch between them when needed without losing its connection to the system. This is called a vertical handover. A...

As an efficient data structure for membership testing, the Bloom filter has found wide applications in modern day data networks, including high-speed packet routing for IPbased networks as well as future data-centric networks. In packet routing, Bloom filters are mainly used to pre-process incoming routing queries so as to minimize unnecessary look...

Joining objects from different web sources and returning top-k combinations is a research topic with much attention. Such techniques could be used in location based scenarios, which for one example, help plan a wonderful night by finding a good combination of hotel, restaurant and theater. Challenge to such techniques is that in a good combination,...

In a content centric network, packet forwarding is performed over data names instead of IP addresses. Since data names are order-of-magnitude larger in number and complexity, CAM-based or Trie-based techniques are not applicable any more. and new forwarding schemes are proposed to solve the problem. These schemes use hashing to store the large rout...

TCP is not designed to be used in a wireless mobile environment. It lacks the capability to handle issues caused by handover, especially those between heterogeneous networks. In this paper a mobility enhancement is proposed for TCP to handle these mobility issues. This enhancement does not change the behaviour of TCP in all normal situations and is...

In a heterogeneous mobile networking environment, when a mobile user needs to perform a handover and switch to a new network, besides all the mobility management procedures to keep its connections alive and divert its on-going flows to the new location, the transmission rate of these flows should also be correctly adapted to match the conditions of...

Over the past decade and more, several accurate but complex traffic models have been developed by just as many researchers. Among the most accurate models are those based on mathematical principles that are able to model the multifractal nature of network traffic. Unfortunately these models are hardly even usable by network engineers because they l...

In this paper, we present a performance comparison of three different MAC layer protocols that can be used in access BPL for power grid monitoring and control. Since the traditional power supply monitoring network is gradually being replaced by a new way of distributed generation. The advanced possibilities of decentralized intelligent control, mul...

A large number of research articles are devoted to queuing theory and queuing systems. Most of these articles employ a continuous representation of network traffic, in the form of timestamps or interarrival times. In this, there is a contradiction with more recent traffic models capable of capturing the multi-fractal nature of network traffic e.g....

TCP-friendly rate control (TFRC) is a congestion control mechanism that can compete fairly with TCP while maintaining a much smoother transmission rate. The smoothness is achieved at the cost of responsiveness, which makes it slow to settle down when handed-over to a different network. In this paper we will study how to improve the TFRC performance...

In this paper we propose a vertical handover mechanism for TCP to deal with the delay and bandwidth change during the handover. The proposed mechanism relies on the interaction between the sender and the receiver during the handover and requires no a prior information of the new path. The adaptation is triggered by a handover notification at the re...

TCP-friendly rate control(TFRC) is an equation-based congestion control mechanism that competes fairly with TCP but has a much lower throughput variation, which makes it a better choice for streaming over the Internet. It is known that in a mobile network environment, after a handover TFRC can overshoot or under utilize the new link if the conditio...

Change detection schemes are used in numerous applications, ranging from industrial quality control over component failure in telecommunications networks to edge detection in images. Next to general schemes solving the theoretical problem, several application-specific solutions were developed. In this paper, we look at the problem from a network en...

A large number of research articles are dedicated to queuing theory and queuing systems. Most of these articles employ a continuous representation of network traffic, in the form of timestamps or interarrival times. In this, there is a contradiction with more recent traffic models capable of capturing the multi-fractal nature of network traffic e.g...

The random early detection (RED) is a widely used active queue management (AQM) algorithm for congestion avoidance. It monitors the average queue length to detect incipient congestion and notifies the connections of congestion to adjust their sending rate. During a handover, all the active connections of the mobile node will be diverted to the new...

Performance testing on a network that is loaded by realistic background traffic, is an important issue in the design of network applications. To obtain this background traffic, a packet stream can be captured on a real network. For testing the application under varying network loads, straightforward techniques can be applied to alter the originally...

The size effect in electroplated copper wires has been widely studied recently. However, there is no consensus on the role of various scattering mechanisms. Therefore, an in-depth analysis to reveal the origin of the size effect is needed. In this article, we study the resistivity of fine copper wires whose feature sizes shrink in two dimensions. I...

In this paper we present a research testbed being developed at K.U.Leuven, Belgium, aiming at providing a flexible and convenient testing infrastructure for researchers working on mobility issues over IP networks. The testbed is built on general-purpose PCs, which makes it suitable for most laboratories. Its user-level modularity makes it easy for...

Recent researches on TCP performance show that spurious timeouts due to an unexpected delay increase can considerably degrade TCP performance. When experiencing spurious timeouts, common TCP implementations misjudge the long delay as an indication of packet loss and prematurely resort to loss recovery. To diminish the consequent penalty, the TCP Ei...

While designing network applications, one has to ch eck their performance on a network that is loaded by realisti c background traffic. For this purpose, a packet stream can be captured o n a network to obtain real background traffic. When the application has t o be tested under various network loads, one can use straightforward techniques to alter...