Against a global backdrop of industrialization and urbanization, precise measurement of multifactor flows and systematic identification of barriers and drivers are critical for optimizing resource allocation in smart regional development. This study develops an integrated geospatial analytic framework that incorporates mobile signaling data and POI data to quantify the intensity, barriers, and driving mechanisms of urban–rural factor flows in Huzhou City at the township scale. Key findings reveal the following. (1) Urban–rural factor flows exhibit significant spatial polarization, with less than 20% of connections accounting for the majority of flow intensity. The structure shows clear core–periphery differentiation, further shaped by inner heterogeneity and metropolitan spillovers. (2) Barriers demonstrate complex and uneven spatial distributions, with 45.37% of the integrated flow intervals experiencing impediments. Critically, some nodes act as both facilitators and obstacles, depending on the flow type and direction, revealing a metamodern tension between promotion and impairment. (3) Economic vitality plays a crucial role in driving urban–rural factor flow, with different factors having complex, often synergistic or nonlinear effects on both single and integrated flows. The study advances the theoretical understanding of heterogeneous spatial structures in urban–rural systems and provides a replicable analytical framework for diagnosing factor flows in small and medium-sized cities. These insights form a critical basis for designing targeted and adaptive regional governance strategies.
Cultural tourism increasingly occupies a central role in the economic offerings of tourist destinations. Indeed, many stakeholders in the sector leverage the enhancement of the destination’s image as a strategy to promote their services, with particular emphasis on culinary heritage. This approach stands out for its ability to meet the growing demand for authentic and enriching experiences, where immersion in local traditions becomes a key factor in attracting visitors. However, this image-building dynamic extends beyond just gastronomic establishments; it involves all participants in the tourism industry, from private operators to public authorities, working in synergy to enhance the destination's competitiveness. While this trend has become a recurring theme in the tourism industry, it remains a critical challenge for professionals, who must navigate an increasingly competitive international landscape.The aim of this article is to explore the role of gastronomic heritage in enhancing the image of tourist destinations, using the city of Marrakech as a case study. The methodology adopted consists of qualitative interviews conducted with twelve senior executives from both the public and private sectors, aimed at assessing the impact of culinary arts on the city's image. The results reveal that the richness and authenticity of culinary offerings, alongside immersive gastronomic experiences, play a vital role in shaping Marrakech's image as a unique and culturally rich tourist destination. Furthermore, the promotion of this heritage contributes not only to the city’s tourist appeal but also to the local economy, preserving traditional know-how while fostering sustainable growth.
This paper focuses on the challenge of interactively modeling street networks. In this work, we extend the simple fractal model, which is particularly useful for describing small cities or individual districts, by constructing random cities based on a tiling structure over which hyperfractals are distributed. This approach enables the connection of multiple hyperfractal districts, providing a more comprehensive urban representation. Furthermore, we demonstrate how this decomposition can be used to segment a city into distinct districts through fractal analysis. Finally, we present tools for the numerical generation of random cities following this model.
This study examines the relationships among economic growth, idiosyncratic risk, Foreign Direct Investment (FDI), inflation, and Sustainable Development Goals (SDGs) within the Association of Southeast Asian Nations (ASEAN). The research integrates Structural Equation Modeling (SEM) and Generalized Autoregressive Conditional Heteroskedasticity (GARCH) modeling to analyze both structural relationships and volatility dynamics in macroeconomic variables. Economic data from ASEAN member countries were analyzed using SEM with AMOS (Analysis of Moment Structures) to identify direct and indirect relationships among variables, while GARCH modeling using EViews was applied to evaluate time-varying volatility in economic growth. The empirical results indicate a significant positive relationship between idiosyncratic risk and economic growth, suggesting that higher levels of firm- or asset-specific risk may reflect entrepreneurial activity, innovation, and investment in higher-return opportunities that contribute to economic expansion. The analysis also shows that progress toward the Sustainable Development Goals exhibits a relationship with economic performance, although the statistical significance varies across models. Furthermore, the GARCH results confirm the presence of volatility clustering, indicating that past fluctuations in economic growth significantly influence current volatility. These findings highlight the importance of effective risk management and balanced policy strategies that encourage innovation while maintaining economic stability. For ASEAN policymakers, strengthening risk management frameworks, supporting entrepreneurship, and aligning development strategies with sustainability objectives can enhance economic resilience and promote long-term sustainable growth.
Desde hace varias décadas las investigaciones acerca de las percepciones de los residentes sobre los impactos del turismo han sido un tema relevante. Sin embargo, existen segmentos en la población que son vulnerables a los impactos del turismo y que se han considerado poco para su estudio, uno de ellos son los niños residentes de los destinos turísticos, quienes deberían ser tomados en cuenta para lograr los Objetivos de Desarrollo Sustentable de la Agenda 2030, en ese sentido, el objetivo de este trabajo fue identificar información más precisa sobre el estado de conocimiento en el tema. Metodológicamente se realizó una revisión sistemática en dos importantes bases de datos Scopus y Google Scholar y se aplicó el método PRISMA con el fin de sintetizar los resultados encontrados en dicha búsqueda; para complementar la búsqueda, posteriormente se realizó una revisión de literatura tradicional. Los resultados revelan un vacío en la literatura al encontrarse solo 19 artículos que dan a conocer las percepciones de los niños, de su propia voz. Se concluye que se debe realizar más estudios considerando a los niños residentes ya que ellos en un futuro serán la fuerza laboral y estarán al frente de la planificación del espacio turístico.
Recreation leadership. Administration of recreation services, The city as an economic factor. City promotion
Naser Rajabi, Vahid Reza Mirabi, Khosro Moradi Shahdadi
AbstractThe purpose of the current research is to provide a model of ecotourism and sustainable tourism development with an emphasis on foreign exchange and economic development of Qeshm Island. The research method is applicable in terms of purpose, and mixed (qualitative-quantitative) in terms of its implementation. The statistical population in the qualitative section includes 19 experts, including managers and experts in the field of tourism, hoteliers, travel agencies, tours and ecotours; by means of the snowball sampling method, and in the quantitative section, it includes 244 employees of the Cultural Heritage Organization, handicrafts and tourism of Qeshm Free Zone. Data collection in the qualitative part was done using semi-structured interviews of the members of the statistical community, and data collection in the quantitative part was done through a questionnaire. In the data analysis of the qualitative part, the coding process in the MAXQDA 2018 software was used, and in the quantitative part, SPSS 16 and AMOS software were used; and the data was analyzed using the factor analysis method. The results in the qualitative section showed that 207 interview codes, 68 subcategories, and 14 categories were extracted. Causal factors include cultural and social factors, the potential of Qeshm Island for tourism and economic and political factors, background features including geographical location, capacity and potential facilities of Qeshm and geosites, intervening conditions including lack of strategy and proper planning and infrastructural problems as well as strategies and interactions include goal-setting and strategy determination to achieve the goal, education and culture building, and providing suitable infrastructure for tourism. The results of quantitative analysis show the significance of measurement models and structural equations at the confidence level of 95%.Extended Abstract IntroductionEcotourism generally refers to tourism activities that are environmentally accountable and whose purpose is to protect the environment, improve people's knowledge about the environment, and local economic development. (Buckley, 2009) Ecotourism is usually related to natural areas and wild environments, and protects natural resources and wild species, and promotes the local economy (De Grosbois & Fennell, 2021). Ecotourism has become an integral part of tourism to increase awareness about environmental protection and reduce the negative effects of tourism while using sustainable natural and cultural tourism attractions (Darda & Bhuiyan, 2022). Sustainable development is a new concept that was formed after the industrial revolution and the problems created in connection with the industrialization of cities and the technological development of cities and the economic, cultural, political and social connection and special attention to ecological considerations (Masrouri Jannett & Falahat, 2016). Sustainable tourism is a sustainable method in the tourism industry and looks at all the effects of tourism, either positive or negative, with the aim of maximizing positive effects and minimizing negative effects (Mohammed, 2022). Ecotourism is a sustainable alternative to degraded livelihoods around protected areas in developing countries, and its contribution to poverty reduction is evident in terms of employment and income generation. As a result, studies of ecotourism partnerships evaluating have traditionally focused on the accumulation and distribution of economic benefits (Agyeman et al, 2019). Based on the said material, the researcher is trying to answer the question: How are ecotourism and sustainable tourism development with an emphasis on foreign exchange and economic development of Qeshm Island?Theoretical frameworkTourism and ecotourismTourism is an economic and social activity that includes the travel and stay of people in places and areas outside of their residence. This activity includes observing tourist attractions, culture and entertainment in different destinations. Tourism can help the economic and cultural development of different regions and play an important role in creating jobs and increasing local income (Camilleri, 2018). Ecotourism is considered as a branch of tourism that focuses on environmental protection, sustainable development and promotion of local economy. Ecotourism pays attention to natural areas and pristine environments and tries to preserve them. This type of tourism emphasizes social and environmental responsibility and emphasizes the direct relationship with local communities and the protection of natural resources (Fennell, 2014).Sustainable DevelopmentDevelopment and sustainability is one of the relatively new concepts in the world development literature, and was first used in the United Nations Summit under the title of Human Environment in Stockholm in 1372. Sustainability is an effort to achieve the best results in human and natural environment programs that are carried out for the present and unlimitedly for the future. Sustainability is a local, sensible, cooperative, and balanced process; performed in a balanced ecological environment, without export its problems to the surrounding areas or leave them on the shoulders of future generations (Asadiyan, 2023).Currency exchange production and economic developmentCurrency production means less import and more export of goods and services. Economic development means increasing production, employment, welfare and economic growth. These two concepts are directly related to each other (Cypher, 2014).Ruzbeh et al, (2023) investigated the presentation of the green governance model with a sustainable development approach in the health system (the case study of hospitals in Kerman city). The research findings showed that the causal factors include: balanced and integrated management, service provision, and financial resources; background factors Include: legal environment, political environment, cultural and social environment, and technology; intervention factors include: government policies; management of change strategies include: green governance affairs, contractual affairs, and partnership affairs; consequences include: creating alignment between policy goals and structure and culture in the health sector, promotion of administrative and environmental health, dynamism and adapting to changes and developments in the health system.Nikfar (2023) investigated the evaluation and analysis of the role of ecotourism in urban development (case study: Zone 1 of Tehran). The results of the research showed that Tehran region 1 has the capabilities and potential of many natural attractions to attract ecotourism, and economic, institutional, social and cultural factors are considered to be the most important obstacles and challenges for the development of ecotourism in Tehran region 1, and ecotourism in Tehran region 1 can also play an effective role in the goals of urban development of Tehran city.Research methodologyThe research method is applicable in terms of purpose, and mixed (qualitative-quantitative) in terms of its implementation. The statistical population in the qualitative section includes 19 experts, including managers and experts in the field of tourism, hoteliers, travel agencies, tours and ecotours; by means of the snowball sampling method, and in the quantitative section, it includes 244 employees of the Cultural Heritage Organization, handicrafts and tourism of Qeshm Free Zone. Data collection in the qualitative part was done using semi-structured interviews of the members of the statistical community, and data collection in the quantitative part was done through a questionnaire.Research findingsIn the data analysis of the qualitative part, the coding process in the MAXQDA 2018 software was used, and in the quantitative part, SPSS 16 and AMOS software were used; and the data was analyzed using the factor analysis method. The results in the qualitative section showed that 207 interview codes, 68 subcategories, and 14 categories were extracted. Causal factors include cultural and social factors, the potential of Qeshm Island for tourism and economic and political factors, background features including geographical location, capacity and potential facilities of Qeshm and geosites, intervening conditions including lack of strategy and proper planning and infrastructural problems as well as strategies and interactions include goal-setting and strategy determination to achieve the goal, education and culture building, and providing suitable infrastructure for tourism. The results of quantitative analysis show the significance of measurement models and structural equations at the confidence level of 95%.ConclusionThe current research was conducted with the aim of providing a model of ecotourism and sustainable tourism development with an emphasis on foreign exchange and economic development of Qeshm Island. The results of this research are in agreement with the results of Ruzbeh et al, (2023), Nikfar (2023), Mobasheri et al, (2023), Ghasemlu et al, (2022), Salman et al, (2022), Darda & Bhuiyan (2022), Hashemi Asl (2020), and Agyeman et al, (2019). Nikfar (2023) showed that the city of Tehran has many capabilities and potentials of natural attractions to attract ecotourism, and economic, institutional, social and cultural factors are considered to be the most important obstacles and challenges for the development of ecotourism in the 1st region of Tehran, and ecotourism in Tehran region 1 can also play an effective role in the goals of urban development of Tehran city.According to the results of this research, it is suggested that the development of sustainable tourism in Qeshm Island requires extensive and coordinated measures. Among the important actions, we can point out the examples of the experiences of successful countries and cities, protecting tourist places by establishing laws, promoting ecotourism and encouraging ecotourism activities. Also, the development of suitable infrastructure for tourism, the use of renewable energy sources, and the support of local communities and economies are also of great importance. These measures, if implemented correctly, can help develop sustainable tourism and preserve the environment and local culture in Qeshm Island.
Enhanced efforts in the transportation sector should be implemented to mitigate the adverse effects of CO2 emissions resulting from zoning-based planning paradigms. The innovative concept of the 15-minute city, with a focus on proximity-based planning, holds promise in minimizing unnecessary travel and advancing the progress toward achieving carbon neutrality. However, an important research question that remains insufficiently explored is: to what extent is a 15-minute city concept within reach for US cities? This paper establishes a comprehensive framework to evaluate the 15-minute city concept using SafeGraph Point of Interest (POI) check-in data in the 12 most populous US cities. The results reveal that residents are more likely to rely on cars due to the fact that most of their essential activities are located beyond convenient walking, cycling, and public transit distances. However, there is significant potential for the implementation of the 15-minute city concept, as most residents' current activities can be accommodated within a 15-minute radius by the aforementioned low-emission modes of transportation. Our findings can offer policymakers insight into how far US cities are away from the 15-minute city and the potential CO2 emission reduction they can expect if the concept is successfully implemented.
Cruz García Lirios, Gilberto Bermúdez-Ruíz, Margarita Juárez-Nájera
The pandemic caused by SARS CoV-2 and the COVID-19 disease have linked tourism with local entrepreneurship. It is a phenomenon in which political actors, economic and social agents converge in order to reactivate the local economy. In this vein, the objective of this work was to validate an entrepreneurship scale, considering four dimensions: trust. opportunity, optimization and innovation. An exploratory, cross-sectional and psychometric work was carried out with a sample of 100 coffee growers from central Mexico. Four factors were established that explained 32% of the variance, suggesting the contrast in another sample. In relation to the state of the art, the scope of the study is discussed.
Recreation leadership. Administration of recreation services, The city as an economic factor. City promotion
Karim Zohrevandian, Iman Ghafari, Mohammad Zohrevandian
Introduction: To stay in a competitive market, organizations need to focus on customers as the key elements of the market. In this regard, one of the techniques that help organizations is customer relationship management, which strengthens the relationship of the organization with customers and makes them loyal to it. Of course, in order to gain loyal customers, communication with the customer is not enough, but the quality of this relationship is also very important. In other words, a strong relationship with customers is the most important key to the success of any business. Many customer behaviors towards service providers are influenced by the type of relationship between customers and service providers. On the other hand, marketing science seeks to know the customer and how his or her behavioral responses affect marketing actions. Therefore, the purpose of this study is to investigate the effect of relationship quality on Customer’s Economic Behaviors in Arak's Sport Clubs. Methodology: The present study is a descriptive-correlational research that has been done using structural equations. The statistical population of the study included the customers of health and fitness clubs in Arak. The statistical sample was selected by a stratified and geographical method. The selected classes were from the north, south, east, west and center of the city. As many as 300 people were considered as a sample. After the research questionnaires were distributed, 266 of them were carefully extracted and analyzed. The data were collected by a 19-item questionnaire with four variables including relationship quality (Palmatier, 2007; Roberts et al., 2003), the desire to pay more (Bigne et al., 2008), the desire for re-attendance (Lim, 2006) and customer share (Palmatier, 2007). The validity was tested by an expert panel (N = 15). The reliability was done by Cronbach's alpha. The data analyses were done using SPSS16 (for preparation of data and descriptive statistics)and the Smart PLS3 Software (to test the research model). Results and Discussion: The descriptive results of the research variables showed that the relationship quality average was 5.31, the average of the desire for re-attendance was 4.98, and the average of the desire to pay more was 4.96, which was higher than the average value of 4. Also, the customer share average was 66.5%. In the inferential part, the fit of the model was examined as the fit of the measurement model and the fit of the structural model. In the measurement model section, the composite reliability (CR) and Cronbach's alpha were greater than 0.7. The total factor loading of the questions was more than 0.4, and their significance coefficients (t coefficients) were higher than 2.58, which indicates the appropriateness of the measurement model. The AVE (average variance extracted) was greater than 0.5 in all the variables, the CR was greater than 0.7, and the CR > AVE condition was met. As a result, it can be said that the convergent validity is acceptable in the measurement model. The results of the divergent validity also showed that the variables in the model of the present study have more interaction with their questions than with other variables. In other words, the divergent validity of the model was adequate. With respect to the fitness of the structural model, the indicators showed that the structural model has a good fit. Also, the path coefficients of the research variables showed that the relationship quality has a positive and significant effect on the desire to pay more (the path coefficient was 0.653). Therefore, if the quality of the customer relationship improves, the customer will be willing to pay more to buy from the club, and, if similar services are offered by competitors at a lower price, he or she will not be willing to leave the club and join a competitor. Also, the quality of the relationship has a positive and significant effect on the desire for re-attendance (with a path coefficient of 0.519). In other words, the customer who finds the quality of relationship with the club desirable will continue to cooperate and buy more from the club. Finally, the relationship quality has a positive and significant effect on customer share (with a path coefficient of 0.495). In other words, a customer who is satisfied with his or her relationship with the club will take a greater share of sporting activities at the club. All this leads to more purchases and higher payments to the club, which brings a profit for the club. Of course, it should be noted that the effect of relationship quality on the tendency to pay more is stronger than the other two variables and has the least effect on customer share. Conclusion: All the efforts of organizations in general and sports clubs in particular are to gain ability to retain their current customers and attract new customers. Customers do not just use the club services; they seek to have a relationship with the club beyond a customer. Research has shown that customer behavior after purchase is affected by the type of service provided and the relationship quality that the organization has established with customers. So, according to the research results, sports clubs should establish a relationship with quality, trust, commitment and customer satisfaction, so that customers, in addition to continuing to attend clubs, will have no problem to pay more for more services and get a greater share of the sports services they need from their current club. If customers perceive this relationship, they will buy more from the club at a higher cost, to the extent that this relationship leads to loyalty and promotion for the club by customers. Finally, it is suggested that clubs influence post-purchase behaviors by designing beautiful spaces in the club environment, consulting with customers, improving the quality of services, establishing communication inside and outside the club, holding festivals with customers and creating emotional relationships with customers.
This paper presents a model for COVID19 in Mexico City. The data analyzed were considered from the appearance of the first case in Mexico until July 2021. In this first approximation the states considered were Susceptible, Infected, Hospitalized, Intensive Care Unit, Intubated, and Dead. As a consequence of the lack of coronavirus testing, the number of infected and dead people is underestimated, although the results obtained give a good approximation to the evolution of the pandemic in Mexico City. The model is based on a discrete-time Markov chain considering data provided by the Mexican government, the main objective is to estimate the transient probabilities from one state to another for the Mexico City case.
Sponge city construction is a new concept of urban stormwater management, which can effectively relieve urban flooding, reduce non-point source pollution, and promote the usage of rainwater resources, often including the application of Low Impact Development (LID) techniques. Although 30 cities in China have been chosen to implement sponge city construction, there is a lack of a quantitative evaluation method to evaluate the environmental, economic, and social benefits of LID practices. This paper develops a comprehensive evaluation system to quantify the benefits of different combinations of LID units using the Storm Water Management Model (SWMM) and the Analytical Hierarchy Process (AHP) method. The performance of five LID design scenarios with different locations and sizes of the bio-retention facility, the grassed swale, the sunken green space, the permeable pavement, and the storage tank were analyzed for a sports center project in Guangxi, China. Results indicated that the green scenario that contains 34.5% of bio-retention facilities and 46.0% of sunken green spaces had the best comprehensive performance regarding meeting the requirements of 75% annual total runoff reduction and the attainment of good operation performance, rainwater utilization, landscape promotion, and ecological service functions, mainly because they are micro-scale and decentralized facilities that can manage stormwater at the source through the natural process. The optimal scenario was adopted to construct the project, and the proposed evaluation system can also be applied to optimal selection and performance effect evaluation of LID practices in other sponge city projects.
Both within the United States and worldwide, the city of Detroit has become synonymous with economic decline, depopulation, and crime. Is Detroit's situation unique, or can similar neighborhoods be found elsewhere? This study examines Census block group data, as well as local crime statistics for 2014, for a set of five Midwestern cities. Roughly three percent of Chicago's and Milwaukee's block groups--all of which are in majority nonwhite areas--exceed Detroit's median values for certain crimes, vacancies, and a poverty measure. This figure rises to 11 percent for St. Louis, while Minneapolis has only a single "Detroit-like" block group. Detroit's selected areas are more likely to be similar to the entire city itself, both spatially and statistically, while these types of neighborhoods for highly concentrated "pockets" of poverty elsewhere. Development programs that are targeted in one city, therefore, must take these differences into account and should be targeted to appropriate neighborhoods.
Joan Borràs, Gerard Macià, Francesc Albuera
et al.
This paper presents a digital development designed specifically for family tourism with the creation of applications named Costa Daurada Trip&Kids and Terres de l’Ebre Trip&Kids. Its objectives are: 1) to facilitate, through an intelligent system, family tourism experiences to certain tourist attractions, especially beaches, cultural heritage and wine culture, and 2) to improve the experience of families during the visit to the attractions and increase their loyalty degree. These applications use intelligent systems to suggest to families the experiences that best suit their needs (such as children's age, interests, means of transport, etc.), considering the affluences, booking availability, parking options, opening hours or weather forecast, among others, in real time, of the attractions and their surroundings. The applications use gamification tools to enable the collection of user data, as well as to encourage visits to other areas with less popularity and help alleviate overcrowding in most frequented ones. Finally, indicators for tourism destination managers are generated through monitoring the behaviour of users with the applications.
Recreation leadership. Administration of recreation services, The city as an economic factor. City promotion
Drones and other small unmanned aerial vehicles are starting to get permission to fly within city limits. While video cameras are easily available in most cities, their purpose is to guard the streets at ground level. Guarding the aerial space of a city with video cameras is a problem that so far has been largely ignored. In this paper, we present bounds on the number of cameras needed to guard the city's aerial space (roofs, walls, and ground) using cameras with 180-degree range of vision (the region in front of the guard), which is common for most commercial cameras. We assume all buildings are vertical and have a rectangular base. Each camera is placed at a top corner of a building. We considered the following two versions: (i) buildings have an axis-aligned ground base and, (ii) buildings have an arbitrary orientation. We give necessary and sufficient results for (i), necessary results for (ii), and conjecture sufficiency results for (ii). Specifically, for (i) we prove a sufficiency bound of 2k + k/4 +4 on the number of vertex guards, while for (ii) we show that 3k + 1 vertex guards are sometimes necessary, where k is the total number of buildings in the city.
Catherine Angelini, Adam S. Williams, Mathew Kress
et al.
We present an early study designed to analyze how city planning and the health of senior citizens can benefit from the use of augmented reality (AR) using Microsoft's HoloLens. We also explore whether AR and VR can be used to help city planners receive real-time feedback from citizens, such as the elderly, on virtual plans, allowing for informed decisions to be made before any construction begins.
Abstract Background: The development of health theory has deepened the function of city parks. It is urgent to explore the action mechanism and practical experience of city parks from a health promotion perspective. Methods: This paper adopts the dynamic tracking method, which has been widely used in the study of city park health problems. Between 2009 and 2010, the author participated in the redesigning project of WLCP. From 2014 to 2018, the author participated in the health management project of WLCP. Additionally, in order to complete the study more accurately, the author conducted three interviews between April and May 2020. After transcribing, condensing, and categorizing talking content, we summarized the theme structure and results. Results: First, the transformation of the health benefits of city parks depends on the use of residents, and the supportive design is the intermediary mechanism for stimulating park use. Second, residents' demand for health is no longer limited to physical and psychological, but includes a higher level of spiritual satisfaction and a comfortable environment. Third, the supporting design of city parks should include a health management system, and a standardized and normalized management system can alleviate health damage. Conclusions: The theoretical framework, action mechanism and practical experience of city parks from the perspective of health promotion proposed may be applicable to other cities at home and abroad.
Urban scaling laws relate socio-economic, behavioral, and physical variables to the population size of cities and allow for a new paradigm of city planning, and an understanding of urban resilience and economies. Independently of culture and climate, almost all cities exhibit two fundamental scaling exponents, one sub-linear and one super-linear that are related. Here we show that based on fundamental fractal geometric relations of cities we derive both exponents and their relation. Sub-linear scaling arises as the ratio of the fractal dimensions of the road network and the distribution of the population in 3D. Super-linear scaling emerges from human interactions that are constrained by the city geometry. We demonstrate the validity of the framework with data on 4750 European cities. We make several testable predictions, including the relation of average height of cities with population size, and that at a critical population size, growth changes from horizontal densification to three-dimensional growth.
We know that maximal efficiency in physical systems is attained by reversible processes. It is then interesting to see how irreversibility affects efficiency in other systems, e.g., in a city. In this study, we focus on a cyclic process of movements (home to workplace and back to home) in a city to investigate the above question. To this end, we present a minimal model of the movements, along with plausible definitions for the efficiency and irreversibility of the process; more precisely, we take the inverse of the total travel time per number of trips for efficiency and the relative entropy of the forward and backward flow distributions for the process irreversibility. We perform numerical simulations of the model for reasonable choices of the population distribution, the mobility law, and the movement strategy. The results show that the efficiency of movements is indeed negatively correlated with the above measure of irreversibility. The structure of the network and the impact of the flows on the travel times are the main factors here that affect the time intervals of arriving to destinations and returning to origins, which are usually larger than the time interval of the departures. This in turn gives rise to diverging of the backward flows from the forward ones and results to entropy (disorder or uncertainty) production in the system. The findings of this study might be helpful in characterizing more accurately the city efficiency and in better understanding of the main working principles of these complex systems.