scholarly journals Upgrading Spatiotemporal Demographic Data by the Integration of Detailed Population Attributes

2021 ◽  
Vol 3 ◽  
pp. 1-8
Author(s):  
Toshihiro Osaragi ◽  
Ryo Kudo

Abstract. In this study, a method was constructed for adding value to spatiotemporal data by integrating demographic information obtained from Mobile Spatial Statistics (MSS), Person-trip (PT) data, and the national census. We first constructed a model that provided spatiotemporal distribution of occupants in urban areas that vary according to clock time, location, and building use classification. The time, location, and building use classification were employed as keys to integrate demographic information. Weekday and weekend data for the central wards of Tokyo were employed to create estimates of the number of occupants with their detailed attributes. Using numerical examples, we demonstrated that the proposed model can provide demographic spatiotemporal distributions with far higher value than before; in which the buildings people occupy, their reasons for being there, their sex and age bracket, and their residential locations, can all be identified.

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Kaili Yang ◽  
Liyan Xu ◽  
Qi Fan ◽  
Yuwei Gu ◽  
Bo Zhang ◽  
...  

AbstractChina is a populous country but lacks epidemiological data on keratoconus (KC). The present study aimed to investigate the clinical data, demographic data, and visual function (VF) data of KC patients in Central China. A total of 524 KC eyes in 307 KC patients (217 bilateral and 90 unilateral) from Henan Eye Hospital were included in the current study. Demographic and VF data were assessed with questionnaires administered by well-trained staff during face-to-face interviews. Visual acuity value was examined by a qualified optometrist, and the clinical data were measured by professional clinicians. The distributions of sex, residence and education level of KC patients were compared by Chi-square tests, and the ratios of people wearing glasses and rigid gas permeable (RGP) lenses were compared by McNemar tests. General linear models/Chi-squared tests were used to compare the clinical and demographic data according to KC severity. Spearman’s correlation analysis was used to test the associations between the data and KC severity. The mean age at diagnosis was 20.98 ± 6.06 years, and males had a higher ratio of KC than females (P < 0.001). Patients in rural areas had a higher rate of KC than those in urban areas (P = 0.039), and the proportion of KC patients with a higher education level (above high school) was high (P < 0.001). A total of 68.40% of the patients reported eye rubbing and 3.52% had a positive family history. The percentage of people wearing glasses was higher than that of patients wearing RGP lenses (P < 0.001). The total VF score of KC patients was 69.35 ± 15.25. The thinnest corneal thickness (TCT) and stiffness parameter at the first applanation (SP-A1) values were inversely correlated with KC severity (P < 0.05). The mean, steep, and max keratometry (Km, Ks and Kmax) values, the RGP lens use and keratoplasty were positively correlated with KC severity (all P < 0.05). The total VF score of the eye with better VA decreased as the severity increased (r = − 0.21, P = 0.002). The present study comprehensively describes various associated features of KC patients from a tertiary hospital in Central China, providing a reference for understanding the characteristics of KC patients in China.


Author(s):  
Xuan Li ◽  
Bingkui Chen ◽  
Yawen Wang ◽  
Guohua Sun ◽  
Teik C. Lim

In this paper, the planar double-enveloping method is presented for the generation of tooth profiles of the internal gear pair for various applications, such as gerotors and gear reducers. The main characteristic of this method is the existence of double contact between one tooth pair such that the sealing property, the load capacity and the transmission precision can be significantly improved as compared to the conventional configuration by the single-enveloping theory. Firstly, the generation principle of the planar double-enveloping method is introduced. Based on the coordinate transformation and the envelope theory, the general mathematical model of the double-enveloping internal gear pair is presented. By using this model, users can directly design different geometrical shape profiles to obtain a double-enveloping internal gear pair with better meshing characteristics. Secondly, to validate the effectiveness of the proposed model, specific mathematical formulations of three double-enveloping internal gear pairs which apply circular, parabolic and elliptical curves as the generating curves are given. The equations of tooth profiles and meshing are derived and the composition of tooth profiles is analyzed. Finally, numerical examples are provided for an illustration.


Author(s):  
Alessandro Cammarata ◽  
Rosario Sinatra

This paper presents kinematic and dynamic analyses of a two-degree-of-freedom pointing parallel mechanism. The mechanism consists of a moving platform, connected to a fixed platform by two legs of type PUS (prismatic-universal-spherical). At first a simplified kinematic model of the pointing mechanism is introduced. Based on this proposed model, the dynamics equations of the system using the Natural Orthogonal Complement method are developed. Numerical examples of the inverse dynamics results are presented by numerical simulation.


2017 ◽  
Vol 119 (7) ◽  
pp. 1-40 ◽  
Author(s):  
Kori J. Stroub ◽  
Meredith P. Richards

Background While postwar suburban migration established suburbs as relatively affluent, homogeneous white enclaves distinct from the urban core, recent waves of suburbanization and exurbanization have been spurred largely by rapid growth in the nonwhite population. While these increases in suburban racial/ethnic diversity represent a significant evolution of the traditional “chocolate city, vanilla suburbs” dichotomy, scholars have expressed concern that they are worsening racial/ethnic segregation among suburban public school students. Objective In this study, we document shifts in the racial imbalance of suburban schools in terms of several racial/ethnic and geographic dimensions (i.e., multiracial, black–white; between and within suburban districts, among localities). In addition, we extend the urban/suburban dichotomy to provide initial evidence on changes in racial balance in metropolitan exurbs. Finally, we use inferential models to directly examine the impact of changes in racial/ethnic diversity on shifts in racial imbalance. Research Design Using demographic data from the National Center of Education Statistics Common Core of Data on 209 U.S. metropolitan areas, we provide a descriptive analysis of changes in segregation within and between urban, suburban, and exurban localities from 2002 to 2012. We measure segregation using Theil's entropy index, which quantifies racial balance across geographic units. We assess the relationship between demographic change and change in segregation via a series of longitudinal fixed-effects models. Results Longitudinal analyses indicate that increases in racial/ethnic diversity are positively related to change in racial imbalance. However, observed increases in diversity were generally insufficient to produce meaningful increases in segregation. As a result, suburbs and exurbs, like urban areas, experienced little change in segregation, although trends were generally in a negative direction and more localities experienced meaningful declines in segregation than meaningful increases. Findings are less encouraging for suburbs and exurbs than for urban areas and underscore the intractability of black-white racial imbalance and the emerging spatial imbalance of Asians and whites. We also document an important shift in the geographic distribution of segregation, with suburbs now accounting for a plurality of metropolitan segregation. Conclusions Contrary to previous researchers, we do not find evidence that suburban and exurban schools are resegregating, although we fail to document meaningful progress towards racial equity. Moreover, while suburbs are not necessarily resegregating, we find that segregation is suburbanizing, and now accounts for the largest share of segregation of any locality. We conclude with a discussion of recommendations for policy and research.


Mathematics ◽  
2021 ◽  
Vol 9 (18) ◽  
pp. 2208
Author(s):  
Ekaterina Morozova ◽  
Vladimir Panov

This paper deals with the extreme value analysis for the triangular arrays which appear when some parameters of the mixture model vary as the number of observations grows. When the mixing parameter is small, it is natural to associate one of the components with “an impurity” (in the case of regularly varying distribution, “heavy-tailed impurity”), which “pollutes” another component. We show that the set of possible limit distributions is much more diverse than in the classical Fisher–Tippett–Gnedenko theorem, and provide the numerical examples showing the efficiency of the proposed model for studying the maximal values of the stock returns.


2022 ◽  
Vol 17 (1) ◽  
pp. 165-198
Author(s):  
Kamil Matuszelański ◽  
Katarzyna Kopczewska

This study is a comprehensive and modern approach to predict customer churn in the example of an e-commerce retail store operating in Brazil. Our approach consists of three stages in which we combine and use three different datasets: numerical data on orders, textual after-purchase reviews and socio-geo-demographic data from the census. At the pre-processing stage, we find topics from text reviews using Latent Dirichlet Allocation, Dirichlet Multinomial Mixture and Gibbs sampling. In the spatial analysis, we apply DBSCAN to get rural/urban locations and analyse neighbourhoods of customers located with zip codes. At the modelling stage, we apply machine learning extreme gradient boosting and logistic regression. The quality of models is verified with area-under-curve and lift metrics. Explainable artificial intelligence represented with a permutation-based variable importance and a partial dependence profile help to discover the determinants of churn. We show that customers’ propensity to churn depends on: (i) payment value for the first order, number of items bought and shipping cost; (ii) categories of the products bought; (iii) demographic environment of the customer; and (iv) customer location. At the same time, customers’ propensity to churn is not influenced by: (i) population density in the customer’s area and division into rural and urban areas; (ii) quantitative review of the first purchase; and (iii) qualitative review summarised as a topic.


2018 ◽  
Vol 6 (3) ◽  
pp. 429-435 ◽  
Author(s):  
Jungmok Ma

Abstract Proper modeling of the usage phase in Life Cycle Assessment (LCA) is not only critical due to its high impact among life cycle phases but also challenging due to high variations and uncertainty. Furthermore, when multiple products can be utilized, the optimal product usage should be considered together. The robust optimal usage modeling is proposed in this paper as the framework of usage modeling for LCA with consideration of the uncertainty and optimal usage. The proposed method seeks to optimal product usage in order to minimize the environmental impact of the usage phase under uncertainty. Numerical examples demonstrate the application of the robust optimal usage modeling and the difference from the previous approaches. Highlights The robust optimal usage modeling is proposed for the usage modeling of LCA. The proposed model seeks to sustainable product usage under uncertainty. Numerical examples demonstrate the difference from the previous approaches.


2019 ◽  
Vol 5 (1) ◽  
Author(s):  
Krista J Patriquin ◽  
Cylita Guy ◽  
Joshua Hinds ◽  
John M Ratcliffe

Abstract Understanding how wildlife respond to ever-encroaching urbanization is of great concern. Bats are the second-most speciose mammalian order and while many appear to be urban adapted, we currently have a limited understanding of their demography and habitat use within urban environments. Using a combination of captures to obtain demographic data, radio-telemetry to examine foraging and roosting behaviour, and data on diet and prey availability, we examined how big brown bats (Eptesicus fuscus), a synurbic species, use an urban green space (High Park) in Canada’s largest city centre, Toronto. We found that adult males outnumbered adult females more than two to one and that males were found throughout the park, while females were concentrated in an area with greater access to water, but lower prey availability. We also found that bats of both sexes were in poorer body condition than reported for other non-urban areas, including a site within southern Ontario. Our data suggest that High Park may not provide adequate resources for reproductive females as they were never found roosting in the park and beetles, their preferred prey, were limited. Although previous studies suggest urban green spaces may offer refuge to bats, most have not considered sex-specific responses to urbanization as they have largely been based on acoustic surveys. Our study therefore highlights the importance of considering demographic differences in response to urbanization to better inform urban management plans and green space development.


2020 ◽  
Vol 12 (3) ◽  
pp. 1077
Author(s):  
Keyju Lee ◽  
Junjae Chae ◽  
Bomi Song ◽  
Donghyun Choi

In Southeast Asian cities, it is common for logistic companies to operate a heterogeneous fleet of delivery vehicles with motorcycles being the preferred vehicle to handle the final phase of delivery. In such scenarios, heterogeneous fleet vehicle routing problem (HFVRP) is generally applied to plan an optimal delivery. However, in many downtown cores of large and rapidly developing Southeast Asian cities, HFVRP is neither viable nor reliable because of road usage restrictions. The purpose of this article is to develop and test a different approach that accurately takes these restrictions into account and provides viable and more sustainable results. Restrictions in this paper refer to situations of urban areas in Vietnam where (i) certain vehicle types are prohibited in specified areas or where narrow alleyways limit the utilization of vehicles that exceed the road capacity and (ii) certain roads are exclusive to certain vehicle types. In networks, limited access and exclusive lanes are represented as links, or arcs, exclusive to one or another. Taking these limitations into consideration, we have developed a unique model, which we have termed Vehicle Routing Problem with Exclusive Links (VRP-EL). The model was validated and tested for its performance on scenarios with varying ratios of exclusive links. Scenarios up to 500 customers were tested on a meta-heuristic algorithm, simulated annealing. VRP-EL produces realistic outcomes. Limiting certain links to be selected according to vehicle types increases overall travel distance. However, this increase outweighs the cost of re-planning and rerouting had they not been constrained initially. The reduction in traveling distance leads to fossil fuel reduction for the overall system. The estimation of reduced carbon emissions through applying the proposed model is presented. Considering the severe traffic congestion and carbon emissions caused by motorcycles in Vietnam, the proposed model leads to a sustainable road environment.


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