Analysis and Forecast of Railway Freight Volume based on Prophet-Deep AR Model

The research on railway freight volume forecast is of great significance to the allocation of railway freight transport resources, the formulation of transport plans and the organization of railway freight transport. This study, by fully mining the railway freight ticket data information, put forward the precise forecast model of railway freight volume under different types of freight. Firstly, the railway freight ticket data are cleaned, regulated and integrated, and the time series of the daily number of railway freight trains are constructed, get the trend, periodicity and holiday data of railway traffic data, and set the parameters of Chinese holidays and rest days according to the demand characteristics of different categories. Secondly, the forecasting result of the Prophet is taken as a cooperative parameter. DeepAR is used to forecast, and a combined model of the Prophet-DeepAR is constructed. Finally, the combined model was validated with Shanghai Railway Bureau data from January 1, 2015 to December 31, 2018 for the food and tobacco category, and with Prophet-DeepAR, LSTM, Wavelet, BILSTM, and Prophet-LSTM, prophet-wavelet and Prophet-Bilstm are used to compare the prediction results. The results show that the Prophet-DeepAR model can extract the multi-dimensional periodicity of freight traffic and mine the trend information of freight traffic, and get the prediction result with high precision. It has better accuracy than other models

A Study of Adjacent Intersection Correlation Based on Temporal Graph Attention Network

Traffic state classification and relevance calculation at intersections are both difficult problems in traffic control. In this paper, we propose an intersection relevance model based on a temporal graph attention network, which can solve the above two problems at the same time. First, the intersection features and interaction time of the intersections are regarded as input quantities together with the initial labels of the traffic data. Then, they are inputted into the temporal graph attention (TGAT) model to obtain the classification accuracy of the target intersections in four states—free, stable, slow moving, and congested—and the obtained neighbouring intersection weights are used as the correlation between the intersections. Finally, it is validated by VISSIM simulation experiments. In terms of classification accuracy, the TGAT model has a higher classification accuracy than the three traditional classification models and can cope well with the uneven distribution of the number of samples. The information gain algorithm from the information entropy theory was used to derive the average delay as the most influential factor on intersection status. The correlation from the TGAT model positively correlates with traffic flow, making it interpretable. Using this correlation to control the division of subareas improves the road network’s operational efficiency more than the traditional correlation model does. This demonstrates the effectiveness of the TGAT model’s correlation

Assembling Model and Algorithm of Railway Passengers Distribution

Computer simulation technology is applied to acquire and process passenger flow distribution and assembling. It also provides reference for layout of station facilities and complication of station operation and management plan. On the basis of the investigations on Beijing South Station and analysis of the rule of arrival passenger in the waiting room, the distribution density function is proposed and the passengers\u27 arrival simulation model is developed. Then, the paper presents the passenger regularity arrival algorithm for simulating the arrival waiting process of passengers. The passenger flow simulation system is designed and the assembling calculation method is presented with simulation. According to the time and space distribution characteristics of passenger flow at Beijing South Station, the simulation experiment is conducted to observe the passenger flow dynamic distribution based on the train schedules. The rationality and effectiveness of the proposed model is thus verified

A Repair Method for Missing Traffic Data Based on FCM, Optimized by the Twice Grid Optimization and Sparrow Search Algorithms

Complete traffic sensor data is a significant prerequisite for analyzing the changing rules of traffic flow and formulating traffic control strategies. Nevertheless, the missing traffic data are common in practice. In this study, an improved Fuzzy C-Means algorithm is proposed to repair missing traffic data, and three different repair modes are established according to the correlation of time, space, and attribute value of traffic flow. First, a Twice Grid Optimization (TGO) algorithm is proposed to provide a reliable initial clustering center for the FCM algorithm. Then the Sparrow Search Algorithm (SSA) is used to optimize the fuzzy weighting index m and classification number k of the FCM algorithm. Finally, an experimental test of the traffic sensor data in Shunyi District, Beijing, is employed to verify the effectiveness of the TGO-SSA-FCM. Experimental results showed that the improved algorithm had a better performance than some traditional algorithms, and different data repair modes should be selected under different miss rate conditions

The complete mitochondrial genome of Semblis atrata (Trichoptera: Phryganeidae)

Semblis atrata is one of three Semblis species distributed in clean brooks and streams in northern Eurasia. Genomic DNA of an S. atrata sample was extracted and sequenced for assembly and annotation of its complete mitogenome. The complete mitochondrial genome of S. atrata was 14,909 bp in length and consisted of 13 protein-coding genes, 2 rRNA genes, and 22 tRNA genes. The S. atrata COX1 gene features a CGA start codon, and COX1, COX2, ND1, and ND5 exhibit incomplete stop codons that are presumed to be completed by the addition of 3’ A residues to the mRNA. The nucleotide composition was highly AT biased, accounting for 77.71% of the whole mitogenome. Phylogenetic analysis placed Semblis as sister to Eubasilissa. The complete mitochondrial genome will be helpful for further studies on the population genetics of this species and phylogenetic analyses of Trichoptera

Spatial distribution pattern of channel steepness index as evidence for differential rock uplift along the eastern Altun Shan on the northern Tibetan Plateau

The eastern Altun Shan is a crucial part of the Altun orogenic belt within the Tibetan Plateau. Study of the uplift rate and the related features in this area provides important clues for understanding the uplift mechanism of the Tibetan Plateau as a whole. As an important geomorphic element in landscape development, the fluvial system can record the relationship between tectonic activity and climatic change. In recent years, studies of the Channel Steepness Index Ksn, have been conducted by many researchers, using the geomorphological model of equilibrium channel longitudinal profiles, combining bedrock uplift and river incision and thus making it possible to extract rock uplift history from river profiles. This research show that regional rock uplift rate is a major factor in affecting the Ksn index. Regional tectonic activity and intensity, therefore, can be evaluated from variation in the Ksn index, which can provide a sensitive measure of uplift rate. In this paper, the Digital Elevation Map ‘ASTER GDEM’, with a spatial resolution of 30 m, was utilized as basic data, and combined with ArcGIS and MATLAB software to extract the Ksn index from the equilibrium channel longitudinal profiles model. Meanwhile, we employed statistical methods to analyze the Ksn index. Our results suggest that averaged Ksn indices, obtained from the subrange A，B，C，D, and E of the eastern Altun Shan (from west to east), are 70.93, 139.03, 108.85, 134.44 and 165.39, respectively. Further analysis implies that the variation in this index can be correlated with the distribution pattern of uplift rates within different regions. Its value increases gradually from west to east, reflecting regional uplift rate. Along the western section of the eastern Altun Shan, the uplift rate is slower and characterized by strike-slip movements, while its eastern part has uplifted faster and is controlled by thrust fault systems. Moreover, in contrast with the southern Altun Shan, the uplift rate of the northern part is high. These variations in uplift rate seem to be linked with “the imbricated thrusting transformation-limited extrusion model” of the Tibetan Plateau. Our results can be correlated with previous work on the active characteristics along the eastern Altyn Tagh Fault (ATF)

Fluvial entrenchment and integration of the Sanmen Gorge, the Lower Yellow River

Strategic studies of gravel deposits, in particular using heavy-mineral analyses, have thrown light on the important unresolved question as to the timing of the initiation of the Yellow River drainage through the Sanmen Gorge, which linked the headwaters of that system in the Fenwei Basin and further upstream with the North China Plain and the Pacific Ocean in the east. Survey of the Sanmen Gorge reach revealed previously unrecognized gravel levels: a higher fifth terrace (T5) and a gravel that formed on a high-level planation surface that is preserved on the flanks of the gorge, below the Xiaoshan upland. This high-level gravel differs markedly from the Yellow River terraces, with a lack of material from the upstream catchment, and would appear to represent a small fluvial catchment that developed in the area during the formation of the planation surface, before the Sanmen Gorge was excavated. Comparison was also made with basin-fill gravels from the endorheic fluvio-lacustrine system that existed immediately upstream of the gorge, and was captured by the Yellow River when the latter was cut, and with the modern bedload gravel of the Yellow River in this reach. The former contains significant quantities of unstable hornblende, which implies more local derivation for the endorheic system, whereas the modern bedload resembles the terrace gravels in showing compositional maturity and long-distance transport from upstream within the catchment. The work reinforces a minimum age of 1.2 Ma for the formation of the Sanmen Gorge