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Research Progress in Adsorption/absorption-based Atmospheric Water Harvesting
Li Qing-hui, Pan Xiao-chun, Zuo Xiao-bo, Wang Dai-yao, Zhao Zhi-wei, Liang Jia-liang
Journal of Guangdong University of Technology. 2024, 41 (02): 1-10.
DOI: 10.12052/gdutxb.230090
The technology of adsorption/absorption atmospheric water harvesting is characterized by ease of operation, low energy consumption, and represents an effective measure to mitigate the scarcity of fresh water resources. A systematic review of recent research progress in this field is presented and an introduction is provided to the basic principles and main material categories of adsorption/absorption air water extraction technology, as well as a summary of the material placement structure, equipment operation mode, and application field of adsorption/absorption equipment. Adsorption/absorption materials include traditional porous structural materials, hygroscopic salts, and new organic air water intake materials. Currently, significant advancements have been made in enhancing the adsorption performance of materials, broadening their application scope, and reducing the energy consumption required for water absorption and release. Nevertheless, there are still challenges related to poor mechanical properties and incapability to be shaped into profiles for adsorption/absorption materials that necessitate further comprehensive investigation. The adsorption/absorption equipment can be utilized for air-water intake applications through various structural configurations, including flat placement, central axis placement, fold placement, etc. This equipment is capable of operating in either a daily cycle or multiple cycle mode. Apart from directly collecting liquid water, the adsorption/absorption atmospheric water harvesting equipment can also serve as an innovative solution for cultivating ecological farms, thereby offering potential strategies to mitigate regional freshwater resource scarcity and food shortages.
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Microbially Induced Calcium Carbonate Precipitation Technique Progress and Review of Engineering Applications
Liang Shi-hua, Xie Yun-peng, Deng You-shu
Journal of Guangdong University of Technology. 2024, 41 (02): 11-22.
DOI: 10.12052/gdutxb.230187
Soil cementation and solidification, based on microbially induced calcium carbonate precipitation (MICP) technology, has emerged as research hotspots in geotechnical engineering and geological engineering since the 21st century. In this research, the reinforcement mechanism of MICP technology and the research status of the engineering application and the reinforcement effect and application practice are systematically described and reviewed. The results show that the strength of the site after MICP solidification shows an obvious non-uniformity, and the distribution of calcium carbonate content decreases with depth. In desert environment, the calcium carbonate coating induced by in-situ extraction of bacteria demonstrates superior strength and stability to the traditional Bacillus pasteurelli. The application of new MICP technology, such as microbial cement and microbial brick, shows promising prospects in terms of strength and durability, and new vitality into the realization of China’s double carbon goal. Addressing the factors affecting the precipitation characteristics of calcium carbonate by MICP technology, the uniformity of calcium carbonate distribution at field scale is enhanced, the durability of calcium carbonate skeleton under seasonal changes ensured, and curing efficiency under different environments improved, which should all be prioritized in future research.
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A General Analysis Method of Beam on Elastic Foundation for Pile-braced Deep Foundation Pit
Shi Hong-yan, Tu Bin-hong, Yang De-sen
Journal of Guangdong University of Technology. 2024, 41 (02): 37-43.
DOI: 10.12052/gdutxb.230088
The deformation and force of pile-braced (-anchored) deep foundation pit is commonly determined by method of beam on elastic foundation (MBEF) during its construction process of excavation and support setting case. The existing MBEF uses the following steps for analysis: Firstly, the entire pile is divided into several segments at the braces, and then the continuous conditions of displacement and force balance conditions at the junction of the segments are used to derive the corresponding equations of the undetermined parameters, and then the deformation and force of the supporting system (foundation pit) are analyzed by using the determined parameters. Due to the different number of supports and segments corresponding to different cases, the method must rederive their respective parameter equations according to different cases, which result in complicated calculation process, difficult to form general calculation method and program. In view of the above problems, a recursive formula is established for the undetermined parameters between two adjacent segments by summarizing the support and pile segment into three basic connection forms (namely, the support is connected to the top of the pile, between the two adjacent pile segments and the bottom of the pit) , then deriving the general parametric equations applicable to strutted or anchored retaining structures, arbitrary number of supports and excavation or support setting case. The study results in this research verify the rationality and feasibility of the proposed method.
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Android Malware Application Detection Method Based on Heterogeneous Information Network
Yin Dan-li, Ling Jie
Journal of Guangdong University of Technology. 2024, 41 (02): 56-64.
DOI: 10.12052/gdutxb.230021
To address the problems of camouflage and real-time detection of the traditional Android malware detection methods, a new Android malware detection method based on heterogeneous information networks is proposed. By modeling the Android entities and relationships nodes and edges, respectively, in a heterogeneous information network, two network representation learning models are designed, including the meta-structure attention network representation learning and the incremental learning models. First, the meta-structure attention network representation learning model is used for intra-sample node embedding, and the embedded nodes and labels are input to a deep neural network for training. Then, the incremental learning model is used for learning the extra-sample node embeddings. The top-k algorithm is used to aggregate neighboring nodes within the heterogeneous information network, and the embedded node to be detected is input to the trained deep neural network for detection. Experimental results show that the F 1 value of the proposed method is 97.5%, the accuracy rate is 96.7%, and the average detection time is 3.7 ms, which are better than the existing methods, demonstrating the effectiveness of the proposed method for dealing with Android malware camouflage and for real-time Android malware detection.
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Super-resolution Reconstruction of Images Based on Blueprint Separable Residual Distillation Network
Xiong Rong-sheng, Wang Bang-hai, Yang Xia-ning
Journal of Guangdong University of Technology. 2024, 41 (02): 65-72.
DOI: 10.12052/gdutxb.230022
The performance of single image super-resolution reconstruction based on standard convolution is limited by the redundancy of the stacked network layers, making it difficult to implement the algorithm on the ground. Moreover, the single residual structure of the feature extraction layer cannot efficiently utilize the feature information obtained from convolution. To address these, this paper proposes a residual distillation reuse module based on the existing residual distillation-based structure to reduce the high-frequency information of the image lost in the residual distillation process. In addition, the base residual block is replaced by a blueprint separable convolution to decouple the spatial correlation of the feature map, such that the weight of highly correlated features can be reduced. As a result, the efficiency of convolution can be improved and the number of parameters can be reduced. We conduct comparative experiments on standard datasets such as Set5 to evaluate the proposed algorithm. The experimental results show that the peak signal-to-noise ratio (PSNR) and structural similarity (SSIM) of the proposed algorithm can be improved by approximately 0.06~0.25 dB and 0.004~0.012, respectively, over the lightweightresidual distillation image super-resolution networks.
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Local Orthogonal Feature Fusion for Few-Shot Image Classification
Tu Ze-liang, Cheng Liang-lun, Huang Guo-Heng
Journal of Guangdong University of Technology. 2024, 41 (02): 73-83.
DOI: 10.12052/gdutxb.230015
How to extract important features by existing metric-based few-shot image classification models is a difficulty. A few-shot image classification method based on local orthogonal feature fusion is proposed. First, the feature extraction network is used to simultaneously extract shallow features with rich local details and deep features with strong semantics. Then, a channel attention module and a multi-scale feature adaptive fusion module are used to perform feature enhancement on the channel and scale dimensions of the shallow features, respectively, in order to generate the feature with more salient local features and more scale information. Finally, according to local orthogonal feature extraction and attention fusion, the obtained multi-scale local features and initial deep semantic features are extracted and fused by a local orthogonal feature fusion module. In this way, we can make full use of the local and global feature information of the image. And a feature representation is generated, which can be more representative of the target category. The experimental results on the three public datasets of miniImageNet, tieredImageNet and CUB-200-2011 show that the proposed method can achieve better classification results. The accuracy rate of the proposed method on the 5way-5shot task reaches 81.69%, 85.36% and 89.78% respectively. Compared with the baseline model, the classification accuracy increased by 5.23%, 3.19% and 5.99% respectively.
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Temporal Alignment Style Control in Text-to-Speech Synthesis Algorithm
Guo Ao, Xu Bo-yan, Cai Rui-chu, Hao Zhi-feng
Journal of Guangdong University of Technology. 2024, 41 (02): 84-92.
DOI: 10.12052/gdutxb.230025
The goal of speech synthesis style control is to convert natural language into corresponding expressive audio output. The speech synthesis style control algorithm based on Transformer can improve synthesis speed while maintain its quality. But there still exist some shortcomings. Firstly, there is a problem of missing style in synthesized audio, when there is a large disparity between the length of the style reference audio and text. Secondly, the decoding process based on vanilla attention is prone to problems of repeating, omission and skipping. To address the above problems, a temporal alignment style control speech synthesis algorithm TATTS is proposed, which can effectively utilize temporal information in the encoding and decoding processes, respectively. In the encoding process, TATTS proposes a temporal alignment cross-attention module to jointly train style audio and text representations, which can solve the alignment problem of unequal-length audio and texts. In the decoding process, TATTS considers the monotonicity of audio timing. And a stepwise monotonic multi-head attention mechanism in the Transformer decoder is proposed to solve the problem of misreading in synthesized audio. The experimental results show that, compared with the baseline model, TATTS has increased the naturalness index of audio results on the LJSpeech and VCTK datasets by 3.8% and 4.8%, respectively, and the style similarity index on the VCTK dataset has increased by 10%. Experimental results demonstrate the effectiveness of the synthetic algorithm, and the ability to style control and transfer.
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SR-Det:Towards Robust Detection of Slender and Rotated Objects in Industrial Scene
He Sen-bai, Cheng Liang-lun, Huang Guo-heng, Wu Zhi-chao, Ye Song-hang
Journal of Guangdong University of Technology. 2024, 41 (02): 93-100.
DOI: 10.12052/gdutxb.230027
Though object detection has been widely used in the industrial scene, it still faces the detection problems of crack defects with slender and rotated characteristics. On the one hand, traditional horizontal anchor methods are usually hard to precisely locate the object. On the other hand, CNNs (Convolutional Neural Networks) perform poorly in terms of feature extraction from rotated objects. In addition, normal loss functions are insensitive to slender objects. To address these, this paper proposes a Slender and Rotated Detector (SR-Det) for robust slender and rotated object detection. Specifically, the Rotated Region Calibration (RRC) is designed, which takes horizontal proposals with different scales and aspect ratios as inputs and outputs the corresponding rotation proposals. Then, the Rotated Angle Proposal Align (RAP-Align) is presented to guarantee the quality of extracted feature information. Finally, the Rotated intersection over union(R-IoU) based on Intersection Over Union (IoU) strategy is proposed for guiding the model to maximize the area between predicted box and Ground Truth box. The experiments on metal cans and curtain walls datasets have shown that the method proposed achieves state-of-the-art performance, demonstrating the effectiveness of the proposed algorithm.
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Multiple-kernel One-class Multiple-instance Learning Algorithm
Gu Hui-min, Xiao Yan-shan, Liu Bo
Journal of Guangdong University of Technology. 2024, 41 (02): 101-107.
DOI: 10.12052/gdutxb.230001
By introducing multiple-kernel into one-class multiple-instance learning, this paper proposes a novel multiple-kernel one-class multiple-instance learning based on support vector data description, which aims to solve the problem of multiple-kernel learning of multiple-instance data with a relatively complex distribution structure in practical applications. This algorithm maps multiple-instance data into the feature space through different multiple-kernel functions, and constructs a spherical classifier by using support vector data description algorithm. To iteratively optimize the proposed algorithm adopts an iterative optimization framework, we first initialize the instances in positive bags as positive, and optimize the objective function to build up the classifier. Then, the labels of the positive instances in each bag are updated according to the classifier obtained in the previous step. The experimental results on the Corel, VOC 2007 and Messidor datasets show that the proposed algorithm achieves significantly better classification performance than state-of-the-art methods, demonstrating its feasibility and effectiveness.
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Safe Diagnosis of Pattern Failure of Decentralized Stochastic Discrete Event Systems
Huang Ze-hui, Liu Fu-chun
Journal of Guangdong University of Technology. 2024, 41 (02): 108-115.
DOI: 10.12052/gdutxb.220174
Most existing studies of decentralized stochastic discrete-event systems (SDESs) usually focused on faults caused by a single event, while in many practical applications, faults were usually resulted from the successive occurrence of a series of events. To address the problem of detecting such faults, in this paper, a pattern safe diagnosis method is proposed for decentralized SDESs. First, the notion of pattern safe codiagnosability of decentralized stochastic systems is formalized. Then, by constructing a pattern safe codiagnoser, a sufficient and necessary condition of pattern safe codiagnosability is presented based on the pattern safe codiagnoser for decentralized SDESs. As a result, the pattern safe diagnosis for decentralized SDESs can be performed.
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An Optimized Transceiver Design for Wireless Powered Over-the-air Computation Systems
Hong Ze-bin, Wang Feng
Journal of Guangdong University of Technology. 2024, 41 (02): 116-121.
DOI: 10.12052/gdutxb.220181
A wireless powered over-the-air computation (AirComp) system is studied, where one separately-located energy transmitter (ET) is deployed to charge multiple low-power sensors simultaneously via energy beamforming, and these sensors rely on the harvested energy for sequential data sensing and functional computation along with the access point (AP) . A harvest-then-sense-and-transmit protocol is considered. Under this system setup, an energy-efficient AirComp design is pursued to minimize the transmit energy of the ET, subject to the sensor energy harvesting constraints and the computational mean squared error (MSE) constraints. The energy beamforming vectors of the ET, the receive beamforming vectors of the AP, and the transmit coefficients at the sensors are jointly optimized. Due to the complicated variable coupling, the resultant energy minimization problem is non-convex. As such, an alternating optimization method is presented to obtain a near-optimal design solution in an iteration manner. Numerical results are provided to show the fast convergence performance and the merit of the proposed design solution.
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Nash Differential Game for Discrete-time Markov Jump System with Partially Unknown Transition Probabilities
Zhang Cheng-ke, Xu Meng, Yang Lu
Journal of Guangdong University of Technology. 2024, 41 (02): 129-138.
DOI: 10.12052/gdutxb.230010
It is noted that transition probability matrix elements cannot be fully known. How to study Nash differential game for discrete-time Markov jump system (MJS) under the condition of unknown transition probability is one of the problems to be solved. This problem can provide theoretical support for the application of Nash differential game theory in Markov jump systems with partial unknown transition probability to management problems. Based on it, the case of one-player game, which is called the ε -suboptimal control problem, is firstly studied. By using the free-connection weighting matrix and “complete square” method, the sufficient conditions for the existence of the ε -suboptimal cntrol strategy are obtained, and an explicit expression of the upper bound of the cost function is given. Then, the conditions for the existence of ε -suboptimal Nash equilibrium strategy are equivalent to solving the optimization problem, which satisfied the bilinear matrix inequalities (BMIs) and matrix inequalities. The heuristic algorithm is used to solve the optimization problem to obtain the ε -suboptimal Nash equilibrium strategies. Finally, the numerical examples are provided to demonstrate the validity of the main conclusions.
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