The aim of topology-transparent scheduling algorithms for multi-hop wireless networks is to find a schedule for the nodes that does not need re-computation when the network topology changes. It caters to highly dynami...
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ISBN:
(纸本)9781467393393
The aim of topology-transparent scheduling algorithms for multi-hop wireless networks is to find a schedule for the nodes that does not need re-computation when the network topology changes. It caters to highly dynamic scenarios where topology changes occur faster than the speed at which schedule updates can be orchestrated. These algorithms normally take as input only global network parameters like the maximum number of nodes and the maximum degree of a node in the network, rather than the detailed topology of the network. In this paper, we study two classical topology-transparent scheduling algorithms: the algorithm due to Chlamtac and Farag6 and the optimal algorithm due to Ju and Li. We provide qualitative comparison of the algorithms followed by numerical simulations to study their throughput characteristics which are also compared with those of multi-hop slotted-ALOHA and TDMA.
A key challenge in wireless ad hoc networks is to achieve maximum lifetime for battery-powered mobile devices with dynamic energy efficient algorithms. Recent study in battery technology reveals that the behavior of b...
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A key challenge in wireless ad hoc networks is to achieve maximum lifetime for battery-powered mobile devices with dynamic energy efficient algorithms. Recent study in battery technology reveals that the behavior of battery discharging is more complex than we used to think. Battery powered devices might waste a huge amount of energy if we do not carefully schedule and budget their discharging. In this paper, we introduce a novel energy model for batteries and study the effect of battery behavior on routing in wireless ad hoc networks. Based on this model, we also propose a battery-aware routing protocol. The paper consists of two parts. In Part I of the paper, we propose an on-line computable discrete time analytical model to mathematically model battery discharging behavior. The model has low computational complexity and does not require large look-up tables. It is suitable for on-line battery capacity computation in ad hoc network routing. We use the data collected from actual nickel-cadmium battery to evaluate the performance of our model and the results show that it can accurately capture the behavior of battery discharging. In Part II of the paper [1], a battery-aware routing protocol (BAR) is proposed based on the new battery model. By dynamically choosing the nodes with well recovered batteries as routers, and leaving the "fatigue" nodes for recovery, the BAR protocol can effectively recover the node's battery capacity and achieve higher energy efficiency. Our simulation results show that the BAR protocol can increase network lifetime and total data throughput by up to 28% and 24%, respectively, compared with previous routing protocols. As far as we know, this is the first work considering battery-awareness with an accurate on-line computable battery model in ad hoc network routing. We believe our battery model can be used to explore other energy efficient schemes for wireless networks as well.
In this paper, we utilize 4D tensor structure to explore efficient structure information for 3D facial expression recognition. As a powerful tool to analyze multidimensional nonnegative tensor data, nonnegative tensor...
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In this paper, we utilize 4D tensor structure to explore efficient structure information for 3D facial expression recognition. As a powerful tool to analyze multidimensional nonnegative tensor data, nonnegative tensor factorization(NTF) aims to obtain a partly localized representation of highdimensional tensors. However, the NTF algorithms often suffer from both high computational complexity and memory requirements for high-order tensor data. To overcome these disadvantages, we present a low-rank approximation method to decrease the computation complexity. Meanwhile, we extract local geometric and discriminant information to improve facial recognition. Therefore, we propose fast nonnegative tensor factorization based on graph-preserving(FNTFGP) algorithm for 3D facial expression recognition(FER). It is a trial to explore and apply the proposed method into 3D FER. Experiments are conducted on the BU-3DFE database. The result of experiments shows the validity and efficiency of the proposed approaches. The proposed algorithm opens a promising direction for the higher performance of 3D facial expression recognition.
Over the last decade, application of wavelet transform (WT) has been realised for extracting features during epileptic seizure detection. Although noteworthy developments have been made in WT algorithms, most of the s...
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One problem of dried rubber sheet from natural rubber latex is non-rubber protein contamination and dark color of its films after aging. This study aimed to prepare the dried rubber films with pale-color and low prote...
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One problem of dried rubber sheet from natural rubber latex is non-rubber protein contamination and dark color of its films after aging. This study aimed to prepare the dried rubber films with pale-color and low protein contamination. Some additives and leaching process were chosen to prove this problem. Protein contamination was measured by Kjeldahl method. Color change of CIE L*a*b* scale technique was determined by color spectrophotometer, and E color difference algorithms were calculated for pale-color evaluation. The mechanical properties of thin film were measured by texture analyzer. It was found that both Texapon-N70(70% sodium lauryl ether sulfate) surfactant and 1% Uniphen P-23 preservative were the effective additives to stabilize latex. After appropriate incubation time, these mixtures were leached and centrifuged to remove the soluble serum, and then reprocessed as needed. Increase cycles of re-centrifuged processing could increase the efficacy of deproteinization and color-reducing. However, this reprocess caused the loss of rubber mass from latex, and increased the production cost. Increase amounts of Texapon-N70 also increased the efficacy of deproteinization and color-reducing. The combination with potassium hydroxide(KOH) could enhance the efficacy of deproteinization and color-reducing that could reduce the amount of Texapon-N70 used, but their tensile strength and elongation values slightly decreased. The appropriate condition for this study was 0.5% Texapon-N70, 0.5% KOH, 1% Uniphen P-23, 60 minutes incubation time, and 1 cycle leaching with water that could reduce protein contamination for 91.05% and color change for E=482.22. This condition could be reproducible and scaled-up in pilot scale.
In recent years, modern diagnostic medical technology has developed rapidly, and computer tomography (CT) has become an important tool due to its fast detection speed and low cost. It is frequently used to assist in d...
In recent years, modern diagnostic medical technology has developed rapidly, and computer tomography (CT) has become an important tool due to its fast detection speed and low cost. It is frequently used to assist in diagnosing complex conditions such as fractures and tumors. However, low-dose CT can lead to a decrease in image quality. For de-noising low-dose CT images, the enhanced performance not only relies on local features but also depends on the overall global characteristics due to the specific nature of medical images, where the shape and location of lesions vary for each patient. Nowadays, deep learning methods have gradually replaced traditional methods as the main-stream direction in low-dose CT image denoising, owing to their powerful feature representation capabilities. However, most algorithms still suffer from issues such as unclear local details, blurred line contours, and high computational complexity. In this paper, we propose a medical image denoising method based on gabor filtering neural network, combining the advantages of traditional filters with the unique strengths of deep learning. First, since gabor filtering is particularly effective for medical image processing, we use gabor filter obtained through variational inference instead of traditional convolutions, which enhances performance while reducing computational complexity. Second, we incorporate the use of Transformers in feature extraction to address the limitations of upsampling and downsampling operations, which cannot effectively model long-term context interactions and maintain the overall texture features of the images. Finally, we validate our method on the 2016 AAPM-Mayo Clinic Low-Dose CT Grand Challenge dataset and a fluorescence microscopy denoising dataset. The results show that our approach outperforms existing denoising methods in terms of PSNR, SSIM, and RMSE metrics, demonstrating its superiority.
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