Real - time download prediction based on the k - nearest neighbor method

Author(s):  
Akshata Patil ◽  
Sanchita Jha
2019 ◽  
Vol 13 (1) ◽  
pp. 141-150
Author(s):  
Jinhwan Jang

Background: Real-time Travel Time (TT) information has become an essential component of daily life in modern society. With reliable TT information, road users can increase their productivity by choosing less congested routes or adjusting their trip schedules. Drivers normally prefer departure time-based TT, but most agencies in Korea still provide arrival time-based TT with probe data from Dedicated Short-Range Communications (DSRC) scanners due to a lack of robust prediction techniques. Recently, interest has focused on the conventional k-nearest neighbor (k-NN) method that uses the Euclidean distance for real-time TT prediction. However, conventional k-NN still shows some deficiencies under certain conditions. Methods: This article identifies the cases where conventional k-NN has shortcomings and proposes an improved k-NN method that employs a correlation coefficient as a measure of distance and applies a regression equation to compensate for the difference between current and historical TT. Results: The superiority of the suggested method over conventional k-NN was verified using DSRC probe data gathered on a signalized suburban arterial in Korea, resulting in a decrease in TT prediction error of 3.7 percent points on average. Performance during transition periods where TTs are falling immediately after rising exhibited statistically significant differences by paired t-tests at a significance level of 0.05, yielding p-values of 0.03 and 0.003 for two-day data. Conclusion: The method presented in this study can enhance the accuracy of real-time TT information and consequently improve the productivity of road users.


2013 ◽  
Vol 45 (4-5) ◽  
pp. 589-602 ◽  
Author(s):  
Mahmood Akbari ◽  
Abbas Afshar

Regardless of extensive researches on hydrologic forecasting models, the issue of updating the outputs from forecasting models has remained a main challenge. Most of the existing output updating methods are mainly based on the presence of persistence in the errors. This paper presents an alternative approach to updating the outputs from forecasting models in order to produce more accurate forecast results. The approach uses the concept of the similarity in errors for error prediction. The K nearest neighbor (KNN) algorithm is employed as a similarity-based error prediction model and improvements are made by new data, and two other forms of the KNN are developed in this study. The KNN models are applied for the error prediction of flow forecasting models in two catchments and the updated flows are compared to those of persistence-based methods such as autoregressive (AR) and artificial neural network (ANN) models. The results show that the similarity-based error prediction models can be recognized as an efficient alternative for real-time inflow forecasting, especially where the persistence in the error series of flow forecasting model is relatively low.


Water ◽  
2020 ◽  
Vol 12 (2) ◽  
pp. 440 ◽  
Author(s):  
Moyang Liu ◽  
Yingchun Huang ◽  
Zhijia Li ◽  
Bingxing Tong ◽  
Zhentao Liu ◽  
...  

Flow forecasting is an essential topic for flood prevention and mitigation. This study utilizes a data-driven approach, the Long Short-Term Memory neural network (LSTM), to simulate rainfall–runoff relationships for catchments with different climate conditions. The LSTM method presented was tested in three catchments with distinct climate zones in China. The recurrent neural network (RNN) was adopted for comparison to verify the superiority of the LSTM model in terms of time series prediction problems. The results of LSTM were also compared with a widely used process-based model, the Xinanjiang model (XAJ), as a benchmark to test the applicability of this novel method. The results suggest that LSTM could provide comparable quality predictions as the XAJ model and can be considered an efficient hydrology modeling approach. A real-time forecasting approach coupled with the k-nearest neighbor (KNN) algorithm as an updating method was proposed in this study to generalize the plausibility of the LSTM method for flood forecasting in a decision support system. We compared the simulation results of the LSTM and the LSTM-KNN model, which demonstrated the effectiveness of the LSTM-KNN model in the study areas and underscored the potential of the proposed model for real-time flood forecasting.


2018 ◽  
Vol 8 (8) ◽  
pp. 1346 ◽  
Author(s):  
Ping Zhou ◽  
Gongbo Zhou ◽  
Zhencai Zhu ◽  
Chaoquan Tang ◽  
Zhenzhi He ◽  
...  

With the arrival of the big data era, it has become possible to apply deep learning to the health monitoring of mine production. In this paper, a convolutional neural network (CNN)-based method is proposed to monitor the health condition of the balancing tail ropes (BTRs) of the hoisting system, in which the feature of the BTR image is adaptively extracted using a CNN. This method can automatically detect various BTR faults in real-time, including disproportional spacing, twisted rope, broken strand and broken rope faults. Firstly, a CNN structure is proposed, and regularization technology is adopted to prevent overfitting. Then, a method of image dataset description and establishment that can cover the entire feature space of overhanging BTRs is put forward. Finally, the CNN and two traditional data mining algorithms, namely, k-nearest neighbor (KNN) and an artificial neural network with back propagation (ANN-BP), are adopted to train and test the established dataset, and the influence of hyperparameters on the network diagnostic accuracy is investigated experimentally. The experimental results showed that the CNN could effectively avoid complex steps such as manual feature extraction, that the learning rate and batch-size strongly affected the accuracy and training efficiency, and that the fault diagnosis accuracy of CNN was 100%, which was higher than that of KNN and ANN-BP. Therefore, the proposed CNN with high accuracy, real-time functioning and generalization performance is suitable for application in the health monitoring of hoisting system BTRs.


2021 ◽  
Vol 7 (1) ◽  
pp. 12
Author(s):  
Laurensius Adi Kurniawan ◽  
I Putu Agung Bayupati ◽  
Kadek Suar Wibawa ◽  
I Made Sukarsa ◽  
I Kadek Gunawan

Peningkatan jumlah dan variasi jenis kendaraan terus berkembang seiring dengan meningkatnya permintaan pasar. Permasalahan baru timbul akibat meningkatnya jumlah dan variasi jenis kendaraan seperti meningkatnya pelanggaran lalu lintas dan kriminalitas. Dengan kondisi ini, pengawasan pelanggar lalu lintas dan kriminalitas secara manual oleh pihak berwajib akan lebih sulit dilakukan terutama di daerah perkotaan. Sistem pengenalan jenis dan warna kendaraan atau Vehicle Color, Make and Model Recognition (VCMMR) adalah komponen penting dalam pengembangan sistem pengawasan keamanan di era otomatisasi. Dengan memanfaatkan CCTV, sistem ini dapat diaplikasikan pada sistem gerbang otomatis, pengawasan kendaraan otomatis, pemantauan lalu lintas, dll. Sistem VCMMR yang dapat bekerja secara real-time dapat meningkatkan keamanan dengan menghasilkan data kendaraan lengkap berupa warna, merek dan model kendaraan selain menggunakan pengenalan plat nomor kendaraan. Penelitian ini menggunakan metode k-Nearest Neighbor untuk mengklasifikasikan warna kendaraan dan framework YOLACT dengan arsitektur ResNet-50 yang telah dilatih untuk mengenali merek dan model kendaraan. Dataset dalam penelitian ini terdiri dari 10 jenis kendaraan dengan 40 citra data latih tiap kelas dan 10 warna dengan 25 citra data latih tiap kelas. Pengujian dilakukan menggunakan enam model YOLACT dengan epoch berbeda dan tiga variasi frame sampling untuk mengurangi waktu komputasi. Hasil pengujian pada video data uji empat kendaraan menunjukkan bahwa frame sampling 250 milidetik menghasilkan performa terbaik dengan waktu komputasi rata-rata 16,08 detik. Model YOLACT dengan epoch yang lebih besar mampu mengenali kendaraan yang berada jauh dari kamera (objek kecil) dengan lebih baik, akurasi yang diperoleh yaitu 91,67% pada epoch 517.


Author(s):  
Md Nasim Khan ◽  
Mohamed M. Ahmed

Snowfall negatively affects pavement and visibility conditions, making it one of the major causes of motor vehicle crashes in winter weather. Therefore, providing drivers with real-time roadway weather information during adverse weather is crucial for safe driving. Although road weather stations can provide weather information, these stations are expensive and often do not represent real-time trajectory-level weather information. The main motivation of this study was to develop an affordable in-vehicle snow detection system which can provide trajectory-level weather information in real time. The system utilized SHRP2 Naturalistic Driving Study video data and was based on machine learning techniques. To train the snow detection models, two texture-based image features including gray level co-occurrence matrix (GLCM) and local binary pattern (LBP), and three classification algorithms: support vector machine (SVM), k-nearest neighbor (K-NN), and random forest (RF) were used. The analysis was done on an image dataset consisting of three weather conditions: clear, light snow, and heavy snow. While the highest overall prediction accuracy of the models based on the GLCM features was found to be around 86%, the models considering the LBP based features provided a much higher prediction accuracy of 96%. The snow detection system proposed in this study is cost effective, does not require a lot of technical support, and only needs a single video camera. With the advances in smartphone cameras, simple mobile apps with proper data connectivity can effectively be used to detect roadway weather conditions in real time with reasonable accuracy.


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