Comparative Study of Spatial Prediction Models for Estimating PM$$_{2.5}$$ Concentration Level in Urban Areas

Author(s):  
Irvin Rosendo Vargas-Campos ◽  
Edwin Villanueva
2018 ◽  
Vol 8 (1) ◽  
pp. 16 ◽  
Author(s):  
Irina Matijosaitiene ◽  
Peng Zhao ◽  
Sylvain Jaume ◽  
Joseph Gilkey Jr

Predicting the exact urban places where crime is most likely to occur is one of the greatest interests for Police Departments. Therefore, the goal of the research presented in this paper is to identify specific urban areas where a crime could happen in Manhattan, NY for every hour of a day. The outputs from this research are the following: (i) predicted land uses that generates the top three most committed crimes in Manhattan, by using machine learning (random forest and logistic regression), (ii) identifying the exact hours when most of the assaults are committed, together with hot spots during these hours, by applying time series and hot spot analysis, (iii) built hourly prediction models for assaults based on the land use, by deploying logistic regression. Assault, as a physical attack on someone, according to criminal law, is identified as the third most committed crime in Manhattan. Land use (residential, commercial, recreational, mixed use etc.) is assigned to every area or lot in Manhattan, determining the actual use or activities within each particular lot. While plotting assaults on the map for every hour, this investigation has identified that the hot spots where assaults occur were ‘moving’ and not confined to specific lots within Manhattan. This raises a number of questions: Why are hot spots of assaults not static in an urban environment? What makes them ‘move’—is it a particular urban pattern? Is the ‘movement’ of hot spots related to human activities during the day and night? Answering these questions helps to build the initial frame for assault prediction within every hour of a day. Knowing a specific land use vulnerability to assault during each exact hour can assist the police departments to allocate forces during those hours in risky areas. For the analysis, the study is using two datasets: a crime dataset with geographical locations of crime, date and time, and a geographic dataset about land uses with land use codes for every lot, each obtained from open databases. The study joins two datasets based on the spatial location and classifies data into 24 classes, based on the time range when the assault occurred. Machine learning methods reveal the effect of land uses on larceny, harassment and assault, the three most committed crimes in Manhattan. Finally, logistic regression provides hourly prediction models and unveils the type of land use where assaults could occur during each hour for both day and night.


2021 ◽  
Vol 12 (6) ◽  
pp. 1-19
Author(s):  
Yifan He ◽  
Zhao Li ◽  
Lei Fu ◽  
Anhui Wang ◽  
Peng Zhang ◽  
...  

In the emerging business of food delivery, rider traffic accidents raise financial cost and social traffic burden. Although there has been much effort on traffic accident forecasting using temporal-spatial prediction models, none of the existing work studies the problem of detecting the takeaway rider accidents based on food delivery trajectory data. In this article, we aim to detect whether a takeaway rider meets an accident on a certain time period based on trajectories of food delivery and riders’ contextual information. The food delivery data has a heterogeneous information structure and carries contextual information such as weather and delivery history, and trajectory data are collected as a spatial-temporal sequence. In this article, we propose a TakeAway Rider Accident detection fusion network TARA-Net to jointly model these heterogeneous and spatial-temporal sequence data. We utilize the residual network to extract basic contextual information features and take advantage of a transformer encoder to capture trajectory features. These embedding features are concatenated into a pyramidal feed-forward neural network. We jointly train the above three components to combine the benefits of spatial-temporal trajectory data and sparse basic contextual data for early detecting traffic accidents. Furthermore, although traffic accidents rarely happen in food delivery, we propose a sampling mechanism to alleviate the imbalance of samples when training the model. We evaluate the model on a transportation mode classification dataset Geolife and a real-world Ele.me dataset with over 3 million riders. The experimental results show that the proposed model is superior to the state-of-the-art.


2014 ◽  
Vol 39 (4) ◽  
pp. 28-41
Author(s):  
Mehmet Emin Şalgamcıoğlu ◽  
Alper Ünlü

This study compared the gentrification processes in Cihangir and Tarlabasi. The dynamics of the gentrification process in Cihangir is compared with the vastly different gentrification process in Tarlabasi. Interpretations of gentrification are also included in this paper. The study analyzed the dynamics of the gentrification process in Cihangir, Istanbul (Turkey) to determine the extent of change during the process. Characterization of the Cihangir neighborhood, which distinguishes Cihangir from other gentrified urban areas, is another aspect of this study. The transformation of Cihangir is currently underway; it involves the revolution and renovation of land and buildings, which is known as gentrification. The gentrification process in Cihangir is affected by socio-economic and socio-cultural transformations. This paper examines gentrification in the Cihangir neighborhood, which has occurred spontaneously and supports the perpetuation of social diversity, which occurs in many urban areas. Although Istanbul’s Tarlabasi region exhibits geophysical characteristics that resemble the geophysical characteristics of Cihangir, Tarlabasi is affected by a completely different gentrification process, which is known as planned gentrification. In the context of this study, scholars question whether gentrification is “erasing the social geography of urban land and unique architectural pattern,” or if gentrification represents “the upgrading and renaissance of the urban land.” (Smith, 1996)


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