Qingtian Zeng - Academia.edu (original) (raw)

Papers by Qingtian Zeng

The European Physical Journal D, 2019

Abstract A nonlinear absorption spectrum is proposed for measuring microwave electric fields with... more Abstract A nonlinear absorption spectrum is proposed for measuring microwave electric fields with tunable sensitivity using electromagnetically induced transparency (EIT) in Rydberg atoms. Interacting dark resonances could enhance the nonlinear absorption, which shows a linear relationship with the microwave field (MW) strength. Compared with the linear case, the nonlinear measurement of MW field improves spectrum resolution by about one order of magnitude, the nonlinearity increases the EIT peak values by about two orders of magnitude, moreover the probe sensitivity could be improved by ten times from simulation. It is found that increasing the ratio of two coupling fields can improve probe sensitivity. The maximum probe sensitivity is predicted and explained. The above results can be well understood with the aid of the dressed-state theory. Graphical abstract

Journal of the Optical Society of America B, 2019

We propose a method of measuring the van der Waals interaction in an ensemble of cold Rydberg ato... more We propose a method of measuring the van der Waals interaction in an ensemble of cold Rydberg atoms via electromagnetically induced transparency (EIT). By using the method of mean-field approximation, we examine the influence of the van der Waals interaction on the EIT spectrum. It is interesting to find that the van der Waals interaction strength is proportional to frequency shift of the transmission spectrum. This can be used to probe the van der Waals interaction strength. In addition, we discuss the evolution of the van der Waals interaction by adopting the model of the cubic lattice. It is found that the total atoms blockade appears in dense gases under the condition of the strong coupling. Also, we discuss the boundary condition of the total blockade and explain the evolution of the van der Waals interaction.

2014 IEEE 13th International Conference on Trust, Security and Privacy in Computing and Communications, 2014

In cloud computing, hypervisor is the all-powerful software running in the highest privilege laye... more In cloud computing, hypervisor is the all-powerful software running in the highest privilege layer, thus attackers who compromise a hypervisor may jeopardize the whole cloud, especially cause memory corruption of any sensitive workloads within the cloud. In this paper, we propose a novel architecture and approach to provide memory protection from an untrusted hypervisor on current x86 platforms. Unlike previous approaches such as nested virtualization, we do not place another higher privilege TCB below the hypervisor. Instead, our approach introduces a properly isolated tiny TCB running in the same privilege level and the same address space with the hypervisor, and uses this TCB to intercept and validate hypervisor's privilege actions for memory protection. In this way, we can enforce further memory security policies only relying on the TCB even if the hypervisor is fully compromised.

Journal of Systems Engineering and Electronics, 2006

The concept of organization decision support system (ODSS) is defined according to practical appl... more The concept of organization decision support system (ODSS) is defined according to practical applications and novel understanding. And a framework for ODSS is designed. The framework has three components: infrastructure, decision-making process and decision execution process. Infrastructure is responsible to transfer data and information. Decision-making process is the ODSS's soul to support decision-making. Decision execution process is to evaluate and execute decision results derived from decision-making process. The framework presents a kind of logic architecture. An example is given to verify and analyze the framework. The analysis shows that the framework has practical values, and has also reference values for understanding ODSS and for theoretical studies.

International Journal of Applied Earth Observation and Geoinformation, 2013

The Three Gorges occupy 193 km of the middle reaches of the Yangtze River between Fengjie in Chon... more The Three Gorges occupy 193 km of the middle reaches of the Yangtze River between Fengjie in Chongqing and Yichang in Hubei Province, China. Due to steep valley-side slopes and long-term river incision, landslides are a major hazard in the Three Gorges region. In this study, we employ the SBAS InSAR technique to process Envisat SAR images collected between 2003 and 2010. Our time series results enable identification of two distinct landslides with deformation rates of up to 10-15 mm/yr in Badong County, and field evidence is used to verify the positions of these failures. With both descending and ascending observations, two-dimensional velocity fields in north and up directions are recovered to better understand the landslide movements. Obvious correlation between seasonal landslide movements and water level changes is observed, which not only provides strong support of our InSAR time series results, but also indicates the impacts of water level changes to landslide activities.

Journal of Solid State Electrochemistry, 2009

The oxygen transport in the nickel-zirconia composite was investigated using the oxygen permeatio... more The oxygen transport in the nickel-zirconia composite was investigated using the oxygen permeation method. A disk-shaped sample made of nickel (40 vol%) and yttria-stabilized zirconia (YSZ) was used to construct a permeation cell. By exposing one side of the sample to a CO2 gas stream and the other side to a CO stream at elevated temperatures, oxide ions were extracted from

2022 7th International Conference on Image, Vision and Computing (ICIVC)

2018 IEEE International Conference on Signal Processing, Communications and Computing (ICSPCC)

Belief propagation (BP) algorithm of polar codes suffers from very high computational complexity ... more Belief propagation (BP) algorithm of polar codes suffers from very high computational complexity when the iteration number becomes larger. In this paper, an early stopping criterion is proposed to avoid unnecessary iterations efficiently. The proposed only needs to detect whether the proportion of unchanged soft-output messages in a detection space exceeds a threshold. The proposed iteration can achieve a desired trade-off between complexity and decoding performance. Simulation results have shown that when the maximum iteration number is 40, the flooding BP (FO-BP) decoder with the proposed criterion can reduce 82.17% of iterations at 3.5dB compared with the FO-BP decoder without early stopping criterion. The proposed criterion costs Nl32 additions and Nl32 comparisons, where N indicates the code length, which effectively reduces the computational complexity.

Frontiers in Environmental Science

The immune ability of the elderly is not strong, and the functions of the body are in a stage of ... more The immune ability of the elderly is not strong, and the functions of the body are in a stage of degeneration, the ability to clear PM2.5 is reduced, and the cardiopulmonary system is easily affected. Accurate prediction of PM2.5 can provide guidance for the travel of the elderly, thereby reducing the harm of PM2.5 to the elderly. In PM2.5 prediction, existing works usually used shallow graph neural network (GNN) and temporal extraction module to model spatial and temporal dependencies, respectively, and do not uniformly model temporal and spatial dependencies. In addition, shallow GNN cannot capture long-range spatial correlations. External characteristics such as air humidity are also not considered. We propose a spatial-temporal graph ordinary differential equation network (STGODE-M) to tackle these problems. We capture spatial-temporal dynamics through tensor-based ordinary differential equation, so we can build deeper networks and exploit spatial-temporal features simultaneousl...

Entropy

The Belief Propagation (BP) algorithm has the advantages of high-speed decoding and low latency. ... more The Belief Propagation (BP) algorithm has the advantages of high-speed decoding and low latency. To improve the block error rate (BLER) performance of the BP-based algorithm, the BP flipping algorithm was proposed. However, the BP flipping algorithm attempts numerous useless flippings for improving the BLER performance. To reduce the number of decoding attempts needed without any loss of BLER performance, in this paper a metric is presented to evaluate the likelihood that the bits would correct the BP flipping decoding. Based on this, a BP-Step-Flipping (BPSF) algorithm is proposed which only traces the unreliable bits in the flip set (FS) to flip and skips over the reliable ones. In addition, a threshold β is applied when the magnitude of the log–likelihood ratio (LLR) is small, and an enhanced BPSF (EBPSF) algorithm is presented to lower the BLER. With the same FS, the proposed algorithm can reduce the average number of iterations efficiently. Numerical results show the average nu...

Sensors

Network slicing (NS) is an emerging technology in recent years, which enables network operators t... more Network slicing (NS) is an emerging technology in recent years, which enables network operators to slice network resources (e.g., bandwidth, power, spectrum, etc.) in different types of slices, so that it can adapt to different application scenarios of 5 g network: enhanced mobile broadband (eMBB), massive machine-type communications (mMTC) and ultra-reliable and low-latency communications (URLLC). In order to allocate these sliced network resources more effectively to users with different needs, it is important that manage the allocation of network resources. Actually, in the practical network resource allocation problem, the resources of the base station (BS) are limited and the demand of each user for mobile services is different. To better deal with the resource allocation problem, more effective methods and algorithms have emerged in recent years, such as the bidding method, deep learning (DL) algorithm, ant colony algorithm (AG), and wolf colony algorithm (WPA). This paper pro...

Mobile Information Systems

An aspect-based sentiment classification task is a fine-grained sentiment analysis task, which is... more An aspect-based sentiment classification task is a fine-grained sentiment analysis task, which is aimed at identifying the sentiment polarity of a given aspect in subjective sentences. In recent years, some researchers have applied pretrained BERT models to this task. However, existing research only uses the BERT output layer and ignores the syntactic features in the middle layers, leading to deviations in the prediction results. In order to solve above problems, we propose a new model BERT-SFE. Firstly, we explicitly utilize the middle layers of BERT to capture the underlying syntactic features. Secondly, we construct a syntactic feature extraction unit based on Star-Transformer, which uses an auxiliary vector and the star network structure to capture both local and global syntactic information in a sentence. Finally, we merge the syntactic features with the semantic features from the BERT output layer in the feature fusion layer, obtaining a more accurate sentiment representation ...

IEEE Communications Letters

In order to reduce the decoding latency, a new early stopping criterion is proposed for belief pr... more In order to reduce the decoding latency, a new early stopping criterion is proposed for belief propagation (BP) decoding. A kind of special processing elements (PEs) of BP decoder called frozen and information PE (FIPE) is selected to predict whether decoding is successful or not. Statistics indicate that FIPE can be considered reliable when the frozen bit is decoded successfully. The proposed criterion is based on the fact that the number of reliable FIPE increase along with iterations and the variation trend is approximate to the ratio of correct information bits. In the term of hardware complexity, the proposed method has a linear correlation with the number of FIPE. This criterion consumes only ‘xor’ and ‘or’ gates to check stopping condition. Simulation results show that the proposed criterion achieves lower latency than Worst Information Bits (WIB) and Frozen Bit Error Rate (FBER) without BLER degradation compared with fixed and G-matrix. Compared with WIB, FBER, Best Frozen Bits (BFB) criterion, the proposed criterion has the lowest hardware complexity.

2019 2nd International Conference on Safety Produce Informatization (IICSPI), 2019

With the in-depth application of information technology in colleges and universities, a wealth of... more With the in-depth application of information technology in colleges and universities, a wealth of campus networks user data has been accumulated. These data come from different information systems and have significant multi-sources. The fusion, analysis and mining of these data is an important basis for user portraits. In this paper, we firstly integrates students' multi-source data based on data level and feature level, and then constructs user portrait model by model stacking. The user portraits of age, grade, gender and profession dimensions are carried out on real multi-source datasets. The experimental results show that the fusion of multi-source data has better experimental results, and the data level fusion effect is better than the feature level fusion.

Knowledge Science, Engineering and Management, 2018

Considerable amounts of business process event logs can be collected by modern information system... more Considerable amounts of business process event logs can be collected by modern information systems. Process discovery aims to uncover a process model from an event log. Many process discovery approaches have been proposed, however, most of them have difficulties in handling large-scale event logs. Motivated by PageRank, in this paper we propose LogRank, a graph-based ranking model, for event log sampling. Using LogRank, a large-scale event log can be sampled to a smaller size that can be efficiently handled by existing discovery approaches. Moreover, we introduce an approach to measure the quality of a sample log with respect to the original one from a discovery perspective. The proposed sampling approach has been implemented in the open-source process mining toolkit ProM. The experimental analyses with both synthetic and real-life event logs demonstrate that the proposed sampling approach provides an effective solution to improve process discovery efficiency as well as ensuring high quality of the discovered model.

ACM Transactions on Asian and Low-Resource Language Information Processing, 2021

Domain terminologies are a basic resource for various natural language processing tasks. To autom... more Domain terminologies are a basic resource for various natural language processing tasks. To automatically discover terminologies for a domain of interest, most traditional approaches mostly rely on a domain-specific corpus given in advance; thus, the performance of traditional approaches can only be guaranteed when collecting a high-quality domain-specific corpus, which requires extensive human involvement and domain expertise. In this article, we propose a novel approach that is capable of automatically mining domain terminologies using search engine's query log—a type of domain-independent corpus of higher availability, coverage, and timeliness than a manually collected domain-specific corpus. In particular, we represent query log as a heterogeneous network and formulate the task of mining domain terminology as transductive learning on the heterogeneous network. In the proposed approach, the manifold structure of domain-specificity inherent in query log is captured by using a ...

Lecture Notes in Electrical Engineering, 2020

This paper proposes a clustering routing protocol in wireless sensor networks, which combines non... more This paper proposes a clustering routing protocol in wireless sensor networks, which combines non-uniform clustering and inter-cluster multi-hop routing denoted by Adaptive Unequal Clustering Routing Protocol (AUCR). In this protocol, the energy of the candidate cluster head is self-enhanced, and the surrounding node density and the average energy of the nodes within the cluster radius are used to calculate the time of the cluster head. After clustering, each cluster head reaches the sink node by forwarding control information, and the sink node generates the routing table through the artificial bee colony algorithm to complete the data transmission. The cluster head dynamically adjusts its cluster size parameter through the data transmission process and the information exchange between the surrounding cluster heads, and adjusts the cluster size of the common nodes in the cluster by broadcasting. Simulation results show that adaptive intelligent clustering protocol can quickly adapt to network conditions, and can reduce node energy consumption, enhance network balance, and extend network life cycle.

Entropy, 2021

Polar code has been adopted as the control channel coding scheme for the fifth generation (5G), a... more Polar code has been adopted as the control channel coding scheme for the fifth generation (5G), and the performance of short polar codes is receiving intensive attention. The successive cancellation flipping (SC flipping) algorithm suffers a significant performance loss in short block lengths. To address this issue, we propose a double long short-term memory (DLSTM) neural network to locate the first error bit. To enhance the prediction accuracy of the DLSTM network, all frozen bits are clipped in the output layer. Then, Gaussian approximation is applied to measure the channel reliability and rank the flipping set to choose the least reliable position for multi-bit flipping. To be robust under different codewords, padding and masking strategies aid the network architecture to be compatible with multiple block lengths. Numerical results indicate that the error-correction performance of the proposed algorithm is competitive with that of the CA-SCL algorithm. It has better performance ...