Hasil untuk "Geography"

G. Valentine

P. Mires

Yasmine Bedoui, Zein Kallas, Adrià Menéndez i Molist et al.

Pricing is an essential element that significantly impacts the supply chain mechanisms. The primary objective of this study is to explore the transmission of producer-to-consumer prices in the Spanish fresh tomato industry. Employing the Threshold Vector Autoregressive model, and subsequently utilizing the Generalized Impulse Response Function, we investigated the nonlinear price adjustments that occur in response to positive and negative shocks affecting both tomato prices of consumers and producers. The findings show a clear pattern of distinct reactions between segments in response to shocks. Specifically, the speed and intensity of consumer price responses to producer price shocks appear to surpass those observed when producer prices respond to consumer price shocks. Furthermore, it is evident from the current research that the behavior of producers has evolved from earlier studies that utilized outdated information, suggesting a more competitive approach. The research identifies a new trend in producer behavior within the supply chain. By analyzing tomato price fluctuations, it advances current knowledge and provides essential market insights to support informed decision-making.

Verónica Puente, Pablo Martín Botta, Paula Mariela Desimone et al.

En Paicuqui (Antofagasta de la Sierra, Provincia de Catamarca) afloran pigmentos de origen mineral de diversas tonalidades que fueron utilizados entre hace 700 a 500 años AP. Presentamos el trabajo experimental realizado con el propósito de evaluar el comportamiento de esas materias primas, sus colores y composiciones al ser utilizados como pintura pre-cocción en cerámica. Desarrollamos distintas pruebas que involucraron la molienda de los pigmentos, la preparación de pinturas, su aplicación sobre briquetas de arcilla y la cocción bajo condiciones diferenciales de temperatura, atmósferas y tipos de hornos. Analizamos: 1) la incidencia de distintos vehículos para la conformación de las pinturas y el uso e impacto de aglutinantes vegetales para su adherencia sobre superficies de arcilla; 2) la afectación de los tratamientos de superficie bruñido y alisado en la intensidad de los colores percibidos y en la aplicación de las pinturas; 3) el impacto de la temperatura máxima y de las atmósferas de cocción sobre los colores y la composición de los pigmentos, combinando análisis por difracción de rayos X y micro-espectroscopía Raman. Discutimos los resultados alcanzados aportando al conocimiento de las prácticas alfareras desarrolladas en momentos previos a la colonia en el Noroeste argentino y proponemos nuevas líneas de experimentación.

Guangwen Song, Jiajun Liang, Linlin Wu et al.

In recent years, there has been a sharp increase in the number of online fraud cases. However, research on crime geography has paid little attention to online crimes, especially to the influencing factors behind their spatial distributions. Online fraud is closely related to people’s daily internet use. The existing literature has explored the impact of internet use on online crimes based on small samples of individual interviews. There is a lack of large-scale studies from a community perspective. This study applies the routine activity theory to online activities to test the relationship between online fraud alert data and the usage durations of different types of mobile phone users’ applications (apps) for communities in ZG City. It builds negative binomial regression models for analyzing the impact of the usage of different types of apps on the spatial distribution of online fraud. The results reveal that the online fraud crime rate and the online time spent on a financial management app share the most similar spatial distribution. While financial management, online education, transportation, and search engine app usages have a significant positive association with online fraud, the use of a financial management app has the greatest impact. Additionally, time spent on social media, online shopping and entertainment, and mobile reading apps have a significant negative association with online fraud. As not all online activities lead to cybercrime, crime prevention efforts should target specific types of apps, such as financial management, online education, transportation, and search engines.

Françoise Okah Efogo, Paul Awoa Awoa

This article focuses on the challenges that uncertainty poses to countries in global and regional value chains. In this perspective, it focuses specifically on African countries and enriches the results with a comparative approach. Indeed, using a gravity model for 49 African countries and all their trading partners from 1990 to 2019, the paper proposes a comparative analysis of the effects of uncertainty on global trade in value chains and on trade in value chains within Africa. The robustness of the results shows that domestic uncertainty can drive the expansion of intra-African trade in value chains, while uncertainty in the partner country hinders the flourishing of trade relationships within a value chain.

Olivier Chovaux

L’histoire du football est autant écrite dans les grands stades des métropoles que dans ceux plus petits des villes moyennes ou des villages. Le bassin minier du nord de la France en offre un exemple tout à fait éclairant avec le stade de l’Étoile Sportive de Bully-les-Mines. Cette enceinte témoigne du dynamisme du football du Nord de la France dès la veille de la Grande Guerre et des aménagements et des œuvres sociales des Compagnies des Mines. Lieu autant de contrôle social que de réalisation de soi-même, le stade dont la tribune est achevée en 1927 est omnisport tout en devenant le terrain de l’ES Bully qui brille en Coupe de France. Aux heures de l’occupation allemande, le stade devient l’un des lieux de distraction en des temps difficiles. Il est aujourd’hui le théâtre du football amateur du dimanche.

Yuhao Wang, Kailai Wang, Songhua Hu et al.

The rapid evolution of the transportation cybersecurity ecosystem, encompassing cybersecurity, automotive, and transportation and logistics sectors, will lead to the formation of distinct spatial clusters and visitor flow patterns across the US. This study examines the spatiotemporal dynamics of visitor flows, analyzing how socioeconomic factors shape industry clustering and workforce distribution within these evolving sectors. To model and predict visitor flow patterns, we develop a BiTransGCN framework, integrating an attention-based Transformer architecture with a Graph Convolutional Network backbone. By integrating AI-enabled forecasting techniques with spatial analysis, this study improves our ability to track, interpret, and anticipate changes in industry clustering and mobility trends, thereby supporting strategic planning for a secure and resilient transportation network. It offers a data-driven foundation for economic planning, workforce development, and targeted investments in the transportation cybersecurity ecosystem.

Alistair Pattison

This paper provides a novel summary measure of ideological polarization in the American public based on the joint distribution of survey responses. Intuitively, polarization is maximized when views are concentrated at opposing extremes with little mass in between and when opinions are highly correlated across many issues. Using this measure, I show that public polarization has been increasing for the past three decades and that these changes are mostly due to increases in general disagreement, not dimensional collapse. Furthermore, these increases are not explained by the diverging opinions of Democrats and Republicans, nor divergence of opinions across gender, geography, education, or any other demographic divide.

Udayasoorian Kaaviya Priya, Ramalingam Senthil

Residential greening is a critical strategy for mitigating the negative impacts of urbanization on the environment, biodiversity, and human well-being. Proper plant species selection is essential for the success of residential greening projects, as it influences the ecological, aesthetic, and health outcomes. This review provides a comprehensive framework for selecting plant species for residential greening, considering environmental suitability, aesthetic values, maintenance requirements, and potential health effects. The plant’s adaptability to local climatic conditions, soil type, and water availability are key considerations. Aesthetic factors like plant form, texture, color, and seasonal interest should be balanced with maintenance needs, including pruning, fertilization, and pest control. Potential health concerns, like allergenic pollen or toxic properties, must also be evaluated while deploying residential greeneries. The guide emphasizes the importance of selecting native or well-adapted non-invasive species to support local biodiversity and minimize ecological disruption. Employing a systematic approach to plant selection for urban vegetation and residential greening initiatives can enhance the environmental, social, and health benefits. Plant species invasiveness is a critical global concern, with substantial ecological, economic, and social impacts that demand careful consideration in species selection and management. This method maximizes these advantages and promotes long-term sustainability and resilience against the challenges posed by climate change. This present review supports the UN’s Sustainable Development Goal 11: Sustainable Cities and Society.

Arne Tobian, Dieter Gerten, Ingo Fetzer et al.

The planetary boundaries framework defines a safe operating space for humanity. To date, these boundaries have mostly been investigated separately, and it is unclear whether breaching one boundary can lead to the transgression of another. By employing a dynamic global vegetation model, we systematically simulate the strength and direction of the effects of different transgression levels of the climate change boundary (using climate output from ten phase 6 of the Coupled Model Intercomparison Project models for CO _2 levels ranging from 350 ppm to 1000 ppm). We focus on climate change-induced shifts of Earth’s major forest biomes, the control variable for the land-system change boundary, both by the end of this century and, to account for the long-term legacy effect, by the end of the millennium. Our simulations show that while staying within the 350 ppm climate change boundary co-stabilizes the land-system change boundary, breaching it (>450 ppm) leads to critical transgression of the latter, with greater severity the higher the ppm level rises and the more time passes. Specifically, this involves a poleward treeline shift, boreal forest dieback (nearly completely within its current area under extreme climate scenarios), competitive expansion of temperate forest into today’s boreal zone, and a slight tropical forest extension. These interacting changes also affect other planetary boundaries (freshwater change and biosphere integrity) and provide feedback to the climate change boundary itself. Our quantitative process-based study highlights the need for interactions to be studied for a systemic operationalization of the planetary boundaries framework.

Hiroto Akaike

The \textit{slope} of a fibered $3$-folds $f:X \to B$ is a relative numerical invariant defined by $λ(f) := K_{f}^{3}/\mathrm{deg}(f_{\ast}ω_{f})$, where $K_{f}$ is the relative canonical divisor and $ω_{f}$ is the relative dualizing sheaf. Establishing slope inequalities is a fundamental problem in the geography of fibered spaces. In this paper, we introduce a new invariant called the \textit{minimal covering degree} as a gonality-type invariant and study a lower bound of the slope increasing with the covering gonality and the minimal covering degree of the general fiber of $f$.

David Roodman

Hjort and Poulsen (2019) frames the staggered arrival of submarine Internet cables on the shores of Africa circa 2010 as a difference-in-differences natural experiment. The paper finds positive impacts of broadband on individual- and firm-level employment -- with a bias toward skilled employment -- and on nighttime light emissions. These results largely are not robust to alternative geocoding of survey locations, to correcting for a satellite changeover at end-2009, and to revisiting a definition of the treated zone that has no clear technological basis, is narrower than the spatial resolution of nearly all the data sources, and is empirically suboptimal as a representation of the geography of broadband.

M. V. Tamm, M. Oiva, K. D. Mukhina et al.

Cultural data typically contains a variety of biases. In particular, geographical locations are unequally portrayed in media, creating a distorted representation of the world. Identifying and measuring such biases is crucial to understand both the data and the socio-cultural processes that have produced them. Here we suggest to measure geographical biases in a large historical news media corpus by studying the representation of cities. Leveraging ideas of quantitative urban science, we develop a mixed quantitative-qualitative procedure, which allows us to get robust quantitative estimates of the biases. These biases can be further qualitatively interpreted resulting in a hermeneutic feedback loop. We apply this procedure to a corpus of the Soviet newsreel series 'Novosti Dnya' (News of the Day) and show that city representation grows super-linearly with city size, and is further biased by city specialization and geographical location. This allows to systematically identify geographical regions which are explicitly or sneakily emphasized by Soviet propaganda and quantify their importance.

Guo-yuan Huang

It has been claimed that the coherent scattering of relic neutrinos with the Earth will result in a neutrino-antineutrino asymmetry of $\mathcal{O}(10^{-4})$ on the Earth surface, which is five orders of magnitude larger than the naive model expectation. In this work we show that this overdensity was overestimated for the perfectly round Earth by solving the exact solution with partial waves. The maximal asymmetry after summing over all the angular modes is only around $10^{-8}$ above the ground. To achieve the proposed asymmetry of $\mathcal{O}(10^{-4})$, a special geography may be needed as the experimental site.

Edward Armstrong, Miikka Tallavaara, Peter O. Hopcroft et al.

Abstract The Sahara region has experienced periodic wet periods over the Quaternary and beyond. These North African Humid Periods (NAHPs) are astronomically paced by precession which controls the intensity of the African monsoon system. However, most climate models cannot reconcile the magnitude of these events and so the driving mechanisms remain poorly constrained. Here, we utilise a recently developed version of the HadCM3B coupled climate model that simulates 20 NAHPs over the past 800 kyr which have good agreement with NAHPs identified in proxy data. Our results show that precession determines NAHP pacing, but we identify that their amplitude is strongly linked to eccentricity via its control over ice sheet extent. During glacial periods, enhanced ice-albedo driven cooling suppresses NAHP amplitude at precession minima, when humid conditions would otherwise be expected. This highlights the importance of both precession and eccentricity, and the role of high latitude processes in determining the timing and amplitude of the NAHPs. This may have implications for the out of Africa dispersal of plants and animals throughout the Quaternary.

Can Rong, Jingtao Ding, Yong Li

Origin-destination (OD) flow modeling is an extensively researched subject across multiple disciplines, such as the investigation of travel demand in transportation and spatial interaction modeling in geography. However, researchers from different fields tend to employ their own unique research paradigms and lack interdisciplinary communication, preventing the cross-fertilization of knowledge and the development of novel solutions to challenges. This article presents a systematic interdisciplinary survey that comprehensively and holistically scrutinizes OD flows from utilizing fundamental theory to studying the mechanism of population mobility and solving practical problems with engineering techniques, such as computational models. Specifically, regional economics, urban geography, and sociophysics are adept at employing theoretical research methods to explore the underlying mechanisms of OD flows. They have developed three influential theoretical models: the gravity model, the intervening opportunities model, and the radiation model. These models specifically focus on examining the fundamental influences of distance, opportunities, and population on OD flows, respectively. In the meantime, fields such as transportation, urban planning, and computer science primarily focus on addressing four practical problems: OD prediction, OD construction, OD estimation, and OD forecasting. Advanced computational models, such as deep learning models, have gradually been introduced to address these problems more effectively. Finally, based on the existing research, this survey summarizes current challenges and outlines future directions for this topic. Through this survey, we aim to break down the barriers between disciplines in OD flow-related research, fostering interdisciplinary perspectives and modes of thinking.

Ye Hong, Emanuel Stüdeli, Martin Raubal

Detecting travel modes from global navigation satellite system (GNSS) trajectories is essential for understanding individual travel behavior and a prerequisite for achieving sustainable transport systems. While studies have acknowledged the benefits of incorporating geospatial context information into travel mode detection models, few have summarized context modeling approaches and analyzed the significance of these context features, hindering the development of an efficient model. Here, we identify context representations from related work and propose an analytical pipeline to assess the contribution of geospatial context information for travel mode detection based on a random forest model and the SHapley Additive exPlanation (SHAP) method. Through experiments on a large-scale GNSS tracking dataset, we report that features describing relationships with infrastructure networks, such as the distance to the railway or road network, significantly contribute to the model's prediction. Moreover, features related to the geospatial point entities help identify public transport travel, but most land-use and land-cover features barely contribute to the task. We finally reveal that geospatial contexts have distinct contributions in identifying different travel modes, providing insights into selecting appropriate context information and modeling approaches. The results from this study enhance our understanding of the relationship between movement and geospatial context and guide the implementation of effective and efficient transport mode detection models.

Omprokash Das, Christopher Hacon, José Ignacio Yáñez

In this article we define generalized pairs $(X, B+\boldsymbolβ)$ where $X$ is an analytic variety and $\boldsymbolβ$ is a b-(1,1) current. We then prove that almost all standard results of the MMP hold in this generality for compact Kähler varieties of dim $X\leq 3$. More specifically, we prove the cone theorem, existence of flips, existence of log terminal models, log canonical models and Mori fiber spaces, the geography of log canonical and log terminal models, etc.

Luz Niyereth Vásquez Acevedo, Dora Inés Arroyave Giraldo

La pandemia ocasionada por el Covid-19 representó para la escuela cambios importantes en la forma de plantear y conducir su propuesta pedagógica, lo cual hizo necesaria la reflexión sobre los aprendizajes para la vida y la construcción de nuevas ciudadanías. La metodología es resultado de un análisis, interpretación y síntesis documental de textos producidos durante la pandemia y que aportan a la comprensión de los retos que se generan en la postpandemia. Se plantea la escuela como escenario que trasciende la transmisión del conocimiento hacia una ciudadanía que aprende para la vida, en el contexto.  Se resalta la importancia de reconocer los procesos sociales gestados alrededor de la escuela como una oportunidad para fortalecer las relaciones con la comunidad y desde allí, configurar una propuesta educativa que mejore las condiciones del contexto en el que realiza su acción pedagógica.   Finalmente, se enfatiza en la importancia del acto educativo en el emprendimiento de una transformación ciudadana orientada en los principios de equidad y justicia social, como aporte a la construcción de ciudadanías críticas, democráticas y participativas, corresponsables con las comunidades y abiertos a la alteridad.