To address the problem that the existing short-term power load forecasting methods have difficulty in effectively modeling non-linear structures and lack cross-scale and cross-variable interaction capabilities, a short-term power load forecasting model based on Dynamic Convolution Decomposition and Multi-Scale Graph (DCDMSG) was proposed. First,to cope with the complex non-linear structure, a dynamic convolution decomposition method was adopted to decompose the trend and seasonal items in the load sequence. Second, the trend item was forecasted using a linear layer directly, and for the seasonal item, a multi-scale sequence was constructed for deep modeling using an adaptive multi-scale sequence construction method. Third, to model the complex dependencies within and outside the multi-scale sequence, a multi-scale fusion graph was used to capture dependencies within sequences at different scales, a multi-variable correlation graph was utilized to model correlations between variables, and a multi-scale mix-hop propagation was employed to aggregate features in the graph. Finally, the seasonal items were forecasted, and the obtained forecast results were weighted and fused with the trend items' forecast results to obtain the final forecast values. Experimental results show that, on the Australian dataset, the Mean Absolute Error (MAE) and Root Mean Square Error (RMSE) of DCDMSG reached 0.379 MW and 0.529 MW, respectively, which were reduced by 7.11%-21.37% and 9.88%-26.32% compared with all comparison models. On the Cele dataset, DCDMSG achieved an MAE of 0.437 MW and an RMSE of 0.708 MW, representing decreases of 5.61%-24.66% and 5.22%-24.12% over all comparison models. In the short-term power load forecasting task, DCDMSG effectively improves the forecast accuracy through seasonal-trend decomposition as well as cross-scale and cross-variable modeling.
Aspect-Based Sentiment Analysis (ABSA) is a fine-grained sentiment analysis task aiming to analyze sentiment polarity of specific aspect words in a given text. Existing ABSA methods use Graph Convolutional Network (GCN) to process syntactic and semantic information, but they treat all syntactic dependencies of aspect words equally, ignoring the impact of distant unrelated words on target aspect words, resulting in inappropriate weight allocation of target aspect words and viewpoint words, and insufficient extraction of semantic information. Aiming at these issues, an ABSA model integrating syntax and sentiment knowledge was proposed. Firstly, a reachability matrix was constructed according to syntactic information. Based on this, a syntactic enhancement graph was constructed by weighting the central position through the aspect words. Secondly, a semantic enhancement graph was constructed by external emotional knowledge and aspect enhancement, and graph convolution was used to fully model the syntactic enhancement graph and semantic enhancement graph, respectively, so as to form different feature channels. Thirdly, biaffine attention was used to integrate syntactic and semantic information effectively. Finally, average-pooling and concatenation operations were used to obtain the final feature vectors corresponding to the aspect words. Experimental results indicate that compared with the deep dependency aware graph convolutional network model — DA-GCN-BERT (deep Dependency Aware GCN+BERT(Bidirectional Encoder Representations from Transformers)), the proposed model achieves the accuracy improvements of 1.71, 1.41, 1.27, 0.17, and 0.43 percentage points on five publicly available datasets, respectively. It can be seen that the proposed model has strong applicability in the ABSA field.
Sentiment classification in psychological counseling scenes aims to obtain the sentiment polarity of the inquirer’s utterance, which can provide support for establishing psychological counseling Artificial Intelligence (AI) assistants. Existing methods obtain the sentiment polarity of text through contextual information, failing to consider the sentiment transmission between the current sentence and the forward neighbor sentences in the dialogue record. To address the issue, a model for sentiment classification of psychological counseling text was proposed based on Attention Over Attention (AOA) mechanism. Historical sentiment words were assigned weights by temporal sequence, which improved the accuracy of sentiment classification for psychological counseling text. In a dialogue, historical sentiment word sequences of both sides were extracted by constructed sentiment lexicon of mental health. Subsequently, the current sentence and two sequences of historical sentiment words were input into the Bidirectional Long Short-Term Memory (BiLSTM) network to get corresponding feature vectors. The Ebbinghaus forgetting curve was used to allocate internal weights to the sequences of historical sentiment words. Both inertia features and interaction features were captured by AOA mechanism. Then, the above two features along with the text features were input into the classification layer, calculating the probability of sentiment polarity. Experimental results on public dataset Emotional First Aid Dataset show that the proposed model improves F1 value by 1.55% compared with Capsule network and Directional Graph Convolutional Network (Caps-DGCN) model. Hence the proposed model can effectively improve the sentiment classification effect of psychological counseling text.
As one of the basic tasks of natural language processing, new word identification provides theoretical support for the establishment of Chinese dictionary and analysis of word sentiment tendency. However, the current new word identification methods do not consider the homophonic neologism identification, resulting in low precision of homophonic neologism identification. To solve this problem, a Chinese homophonic neologism discovery method based on Pinyin similarity was proposed, and the precision of homophonic neologism identification was improved by introducing the phonetic comparison of new and old words in this method. Firstly, the text was preprocessed, the Average Mutual Information (AMI) was calculated to determine the degree of internal cohesion of candidate words, and the improved branch entropy was used to determine the boundaries of candidate new words. Then, the retained words were transformed into Chinese Pinyin with similar pronunciations and compared to the Chinese Pinyin of the old words in the Chinese dictionary, and the most similar results of comparisons would be retained. Finally, if a comparison result exceeded the threshold, the new word in the result was taken as the homophonic neologism, and its corresponding word was taken as the original word. Experimental results on self built Weibo datasets show that compared with BNshCNs (Blended Numeric and symbolic homophony Chinese Neologisms) and DSSCNN (similarity computing model based on Dependency Syntax and Semantics), the proposed method has the precision, recall and F1 score improved by 0.51 and 5.27 percentage points, 2.91 and 6.31 percentage points, 1.75 and 5.81 percentage points respectively, indicating that the proposed method has better Chinese homophonic neologism identification effect.
For the actual background of the shortage of self-owned vehicles of the transporters in the early stage of emergency, the combinatorial optimization problem of hybrid vehicle paths with transportation mode of joint distribution of self-owned vehicles and vehicles rented by third-party was studied. Firstly, with the different interests between demand points and transporters considered, a multi-objective hybrid vehicle routing optimization model with soft time windows was established with the goal of maximizing system satisfaction and minimizing system delivery time and total cost. Secondly, the shortcomings of NSGA-Ⅱ algorithm in solving this kind of problems such as poor convergence and uneven distribution of Pareto frontiers were considered, the heuristic strategy and pheromone positive feedback mechanism of ant colony algorithm were used to generate offspring population, non-dominated sorting strategy model was used to guide the multi-objective optimization process, and the variable neighborhood descent search was introduced to expand the search space. A multi-objective non-dominated sorting ant colony algorithm was proposed to break through the bottleneck of the original algorithm. The example shows that the proposed model can provide reference for decision makers to choose reasonable paths according to different optimization objectives in different situations, and the proposed algorithm shows better performance in solving different scale problems and different distribution type problems.
Since the cost of mobile crowdsensing in full coverage of area is excessively high, a Compressive Sensing-based mobile crowdsensing Task Distribution (CS-TD) mechanism was proposed. Firstly, an overall cost model of perceived task was proposed. In this model, the number of nodes participating in a perceived task, the number of nodes perceived and data uploaded were comprehensively considered. Then based on cost model, the daily movement trajectory of sensory node was analyzed, by combining with the compressed sensing data acquisition technology, a compressed sensing sampling method based on perceived node trajectory was proposed. Secondly, the optimal node set was selected by the Region Covers Least Nodes (RCLN) algorithm, the tasks were assigned to the nodes, and then the compressed sensing technology was used to recover node data. Finally, the trustworthiness of perceived node was evaluated in iteration of multiple perceived tasks to ensure the optimality of task plan. The CS-TD distribution model was tested several times. Compared with the existing CrowdTasker algorithm, the average cost of CS-TD algorithm is reduced by more than 30%. CS-TD model can effectively reduce consumption of sensing node and reduce overall perceived cost in full coverage sensing task.
The current method of image classification which uses the Speed Up Robust Feature (SURF) is low in efficiency and accuracy. To overcome these shortages, this paper proposed an approach for image classification which uses the statistical features of the SURF set. This approach took all dimensions and scale information of the SURF as independent random variables, and split the data with the sign of Laplace response. Firstly, the SURF vector set of the image was got. Then the feature vector was constructed with the first absolute order central moments and weighted first absolute order central moments of each dimision. Finally, the Support Vector Machine (SVM) accomplished the image classification process with this vector. The experimental results show that the precision of this approach is better than that of the methods of SURF histogram and 3-channel-Gabor texture features by increases of 17.6% and 5.4% respectively. By combining this approach with the HSV histogram, a high-level feature fusion method was got, and good classification performance was obtained. Compared with the fused method of the SURF histogram and HSV histogram, the fused method of 3-channel-Gabor texture features and HSV histogram, and the multiple-instance-learning method based on the model of Bag of Visual Word (BoVW), the fused method of this approach and HSV histogram has better precision with the increases of 5.2%, 6.8% and 3.2% respectively.