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Amid growing academic discourse on teenagers' political rights, this paper argues that the inclusion of teenagers in the decision-making process at the municipal level has positive effects. Based on qualitative and quantitative research on three municipalities in Greece and Sweden, this paper concludes that a level of awareness of the critical issue of climate change leads to a greater propensity for action from municipal councils aimed at restoring the environment. The findings demonstrate that including teenagers in the decision-making process at the local and regional level could lead to a greater focus on forward-thinking policies, particularly in areas concerning young people, such as environmental preservation efforts and democratic rights. [ABSTRACT FROM AUTHOR]

Recent technological developments in aviation, such as vertical take-off and landing and electric engines, are bringing the development of integrated urban air transport systems closer and are generally helping to promote the concept of Urban Air Mobility (UAM). UAM makes it possible to provide integrated air transport services for people and goods in urban areas, reducing travel time initially and leading to cost reductions in the future. The development of UAM will allow urban airspace to be used for short and medium range operations, potentially connecting larger urban areas or neighbouring cities. However, the operation of UAM requires, on the one hand, the development of appropriate urban infrastructure to provide full and vertical support for aircraft, such as vertical landing and take-off areas, specially designed intermediate areas for embarkation and disembarkation of passengers and cargo, as well as areas with operational technical bases for loading, parking and maintenance of aircraft. All this is the concept of the VertiPorts/Voloports/Vertistops. However, the development of a VertiPorts/Voloports/ Vertistops in the dense and complex modern urban environment can be challenging, as on the one hand specific rules for aviation safety have to be followed, and on the other hand their integration into the urban environment requires compliance with the rules of urban planning, land use and protection of private property.This paper presents the challenges that researchers have to face in order to integrate Voloports into an already formed and dense urban environment, such as that of the city Athens, the metropolitan centre and capital of Greece, in respect to various constitutional, institutional and spatial restrictions. [ABSTRACT FROM AUTHOR]

This paper addresses the challenges of calibrating low-cost electrochemical sensor systems for air quality monitoring. The proliferation of pollutants in the atmosphere necessitates efficient monitoring systems, and low-cost sensors offer a promising solution. However, issues such as drift, cross-sensitivity, and inter-unit consistency have raised concerns about their accuracy and reliability. The study explores the following three calibration methods for converting sensor signals to concentration measurements: utilizing manufacturer-provided equations, incorporating machine learning (ML) algorithms, and directly applying ML to voltage signals. Experiments were performed in three urban sites in Greece. High-end instrumentation provided the reference concentrations for training and evaluation of the model. The results reveal that utilizing voltage signals instead of the manufacturer's calibration equations diminishes variability among identical sensors. Moreover, the latter approach enhances calibration efficiency for CO, NO, NO2, and O3 sensors while incorporating voltage signals from all sensors in the ML algorithm, taking advantage of cross-sensitivity to improve calibration performance. The Random Forest ML algorithm is a promising solution for calibrating similar devices for use in urban areas. [ABSTRACT FROM AUTHOR]

The prefecture of Piraeus in Greece is dotted with prior industrial sites that are currently abandoned. This paper addresses the ability of these sites to contribute to sustainable infrastructure and urban development through regeneration, by understanding the history of Piraeus, the environmental and social opportunities that may come from revitalization, and the communities' needs within their municipalities. Additionally, the paper analyzes the European Union's prior policies that have outlined the sustainable development of cities, and the role that the regeneration of brownfields in Greece may play in achieving these policy directives. To do this, the paper addresses the historical emergence of urban sustainability efforts and the funding mechanisms in place today that may be applicable to the case of Piraeus. Additionally, this research takes into account citizens' perspectives on desired future land uses at currently abandoned land in the municipality of Piraeus through public surveys. The paper aims to contextualize future opportunities for the local environments and communities in Piraeus that may come from sustainable regeneration of brownfield sites. [ABSTRACT FROM AUTHOR]

In recent years, researchers and policymakers have emphasised the importance of understanding the complex relationships between Water, Energy, Food and Ecosystems (WEFE). The primary reason for capturing these complexities is to understand how decisions made in the water, food and energy sectors can affect one another. Crucially, biodiversity and ecosystem services (E) play a mediating role in these relationships by making material and non-material contributions to all other sectors (W, E, F). The Nexus approach has been widely used for capturing these interdependencies and identifying opportunities for increasing efficiency, reducing trade-offs and building synergies for sustainable resource use across the WEFE nodes. One challenge in using this framework is the need to harmonise the technical and managerial dimensions of the WEFE interlinkages with the perceptions and priorities of local populations directly involved in the use and management of resources. This paper presents a methodological framework that seeks to integrate the perspectives of experts, practitioners and local stakeholders on the WEFE Nexus through the combined application of the Delphi and Focus Group methods. In this paper, the municipality of Apokoronas in Crete, Greece has served as the case in point. The combined framework allowed us to explore the Nexus understanding at the local level and was instrumental in the identification of initiatives for more integrated resource management. The triangulation of results captured the differences in priorities between practitioners and the local community at large, but also, more specifically, it pointed to discrepancies within groups and across WEFE sectors. The outcomes of this paper demonstrate that awareness and learning play a central role in Nexus actions to overcome conflicts and perceived inequalities, and to internalise solutions. The inclusion of the ecosystems node in the traditional WEF Nexus encouraged participants to contemplate the pivotal role of ecosystems in supporting the rest of the WEF sectors. [ABSTRACT FROM AUTHOR]

Social structure is based on the availability of the Water-Energy-Food Nexus. To cover these needs of society, several solutions of different scales of infrastructures coexist. The construction of infrastructure is capital-intensive; therefore, investment risk is always a consideration. In this paper, we try to evaluate the investment risk by interest rates (IR). We show that IR is a key indicator, which includes multiple parameters of prosperity expressing the political and economic status quo of the society. The selection of a particular scale influences the required capital and is thus one of the most critical decisions. Water supply infrastructure is one of the foundations of society, and the selection of the optimal scale of such infrastructure is often a great challenge in civil engineering. As a case study, we analyse three different scales of water supply infrastructures for the area of West Mani (Greece), i.e., dam, water ponds, and seawater desalination. We evaluate each case by the capital intensity by performing stochastic simulations of interest rates and identify the optimal solution as the one with the smallest median unit cost, in this case, the water ponds. In order to assess the impact of the development level of a country on the resulting unit cost stochastic properties we apply the optimal solution to various countries with different development levels and IR. We show that IR in the least developed countries, being generally higher and more variable, increases the unit cost, including its variability, which ultimately indicates higher investment risk. [ABSTRACT FROM AUTHOR]

A western discourse of public space, originating in ancient Greece and Rome, has been widely used in architectural and urban research in China and is constantly contested in this geographical and cultural context. The contestation often stems from the cultural differences in understanding and operating the collective realms in Chinese and western cities, which is manifested through the distinctive features of their public spaces. This essay frames an alternative perspective on public space in the Chinese context by exploring the cultural, social, and spatial constructions of collective realms in the Chinese city. Starting from the conceptual origin of the 'public' in Chinese philosophy, this paper elaborates on three culturally grounded ideas related to collective patterns of space creation and practice – the relational circle, the realm of strangers, and the marketplace – and examines how these ideas are articulated by architectural and urban archetypes and in urban developments in Chinese cities. [ABSTRACT FROM AUTHOR]

The loss of free and green spaces and their associated advantages for the urban population is a major threat for urban sustainability. The idea of planting roofs in order for them to act as natural filters within the urban tissue has been increasingly recognized as a technology that has the potential to diminish drastically the environmental problems of urban centers. In many countries, special laws are introduced which provide citizens with incentives or even involve an obligation to build green roofs. The objective of the research presented herein is to investigate and record the impact of the use of green roofs for the development of urban policies which aim at improving the quality of urban environment, using a combination of Geographical Information Systems (GIS) technology and specialized software. The developed methodological framework is applied to a real-world case study of a medium - sized Greek city. The use of a comprehensive GIS environment not only contributes to improving the quality of research but also offers the possibility of continuous updated information and monitoring of the factors that influence the development of green roof policies. [ABSTRACT FROM AUTHOR]

Land use patterns and transport system are considered to be the two basic components of the urban development process, and as such they have been in the core of spatial planning policies for the last 4 decades. Land use transport interaction models are computer tools that could help us understand land use changes and organization of human activities in relation to existing or planned transport infrastructure. In this context this paper examines the perspectives of applying a land use transport interaction model for the city of Thessaloniki. Obtaining, preparing and validating socioeconomic data is a crucial part of the modeling process, therefore an extensive search of the required data was performed. The quest for appropriate and suitable data concluded with a detailed recording of emerged problems. In response to the inability of finding suitable data to perform the first step of the modeling process i.e. calibration, the paper concludes with some thoughts related to data availability, organization and standardization issues. Last but not least, the paper stresses out the significance of data availability for utilization of land use transport models, so as not to remain purely academic products but tools with practical value in planning. [ABSTRACT FROM AUTHOR]

Context: A lot of parents whose children are overweight or even obese are in no position to accurately acknowledge the real weight of their children. Parents' perception of their children's weight plays a significant role in the prevention and treatment of childhood obesity. Aims: This paper describes parents' opinions on the real weight status of their children and the sufficiency of quality nutrients in their diet. Settings and Design: The research methodology used in the particular study was based on survey research in preschool settings in West Greece. Methods and Material: The research methodology used in the particular study was based on survey research. Data were collected through questionnaires answered by parents of children attending preschool settings aged between two and five. One hundred and seventy-eight children and their parents participated. All parents had been informed of the aim of the study beforehand and gave their consent on condition that they could withdraw at any stage they wished. Statistical Analysis Used: Data were analyzed using SPSS (Statistical Package for the Social Sciences). Results: Comparing the Body Mass Index of children with the parents' opinion of their children's weight, we noticed 85,71% and 78,13% of the parents whose children were obese and overweight respectively, regarded their weight as normal. The majority of the overweight and obese children's parents were of the opinion that their children's diet was proper and healthy. Conclusions: Most parents whose children were obese or overweight underestimated the real weight of their children and considered their nutrition healthy. [ABSTRACT FROM AUTHOR]

To delineate new directions of urban development in a context of demographic shrinkage in Southern Europe, the present study illustrates a comparative analysis of the demographic balance in metropolitan Athens, Greece (1956–2021). The analysis delineates short-term and long-term dynamics of the natural population balance, considering the impact of the Great Recession and COVID-19 pandemic, and assuming a contemporary increase in gross mortality rates and a marked fertility reduction associated with birth postponement. To address such objectives, we have compared the natural growth of population (the ratio of the total number of births to deaths) at ten year intervals (1956, 1960, 1970, 1980, 1990, 2000, 2009, 2019, 2020, 2021) in 115 municipalities of metropolitan Athens, controlling for the local context. The empirical results of descriptive statistics, spatial analysis, correlation statistics, non-parametric inference, and exploratory multivariate techniques outline the indirect impact of COVID-19 on population dynamics, being in some ways additive to the already observed effects of the Great Recession, reinforcing demographic shrinkage in specific local contexts. The COVID-19 pandemic and the Great Crisis likely accelerated the typical outcomes (population aging and low fertility) of the second demographic transition in Greece. These dynamics are associated with more volatile (and possibly reduced) immigration flows and with enhanced emigration, fueling urban shrinkage and a progressive economic decline of metropolitan regions, as our evidence suggests for Athens. Additional research should ascertain the aggregate, indirect role of pandemics in population dynamics as a proxy of urban and regional decline in European regions exposed to long-term aging. [ABSTRACT FROM AUTHOR]

Transportation projects often require large initial investments and are expected to generate benefits extending far into the future. Thus, there is a need to compare benefits and costs that occur at different periods over time. Since money has a time value, the same amount of money at different time periods does not have the same value. Therefore, it is important to convert costs and benefits into equivalent values when conducting a Cost-Benefit Analysis (CBA). A special category of transportation projects is that of Intelligent Transport Systems (ITS). ITS comprise innovative solutions for travel demand and traffic management, and it is expected to play a key role in future sustainable urban development plans. Compared to other transportation projects, ITS have a lower initial investment. In this paper a framework based on a CBA is presented, assessing costs and benefits of three ITS projects implemented in Thessaloniki, Greece. The paper refers to future developments of ITS in the city of Thessaloniki. The examined systems have already been developed as demonstration systems in various regions throughout Europe. The benefits of the systems have been transferred and scaled up, so as to be in line with the specific characteristics of the Greek environment. [ABSTRACT FROM AUTHOR]

Prior to the economic crisis, forecasts indicated a continuous increase of traffic in European cities, highlighting the need of a policy to alleviate the external impacts of transport. The crisis, however, generated pressures on all sectors of activity, with transport being an indicative example. The reduction of income and employment, the increased vehicle maintenance and renewal costs and the transport related taxation seem to affect the transport system and its external impacts. Thus, taking for granted that Europe will eventually achieve "sustainable recovery" from the crisis, the current period presents an opportunity for promoting sustainable mobility policies and interventions in the most affected by the crisis European cities. Towards this goal, it is essential to capitalise on contemporary techniques for the monitoring of changes in transport external costs. The purpose of the paper is the development of a methodology for the estimation of external costs due to congestion, air pollution, climate change and accidents, based on road traffic data. The methodology is applied along road arteries in Thessaloniki for the period "before and after" the emergence of the crisis. As a result, an overall decrease in external costs is observed, creating an unforeseen "surplus" for the society during the crisis. [ABSTRACT FROM AUTHOR]

It has been proved that urban development patterns affect in various ways cities' environmental quality. To this purpose, one of the factors that have been examined is the role of urban green spaces, in balancing the effects of human activities in dense urban landscapes. One of the major external costs of dense urban environment is smog and greenhouse gas emissions that are heavily related to existing mobility patterns. High levels of concentration of such emissions along with high urban density are considered to be the main reason for cities' environmental degradation. In this context this paper presents the results of a study investigating how urban green spaces can improve air quality, in major transportation axis within the city of Thessaloniki. In order to do so, urban density along the axis, green space per capita, green space spatial distribution, mobility patterns and transport emissions volumes are being considered. Comparison of these indices among the transportation axis under study indicates that there is a positive relation between building density, urban density and volume of emissions observed, while a dispersed rather than a concentrated pattern of green spaces could better help improve cities' environmental quality. [ABSTRACT FROM AUTHOR]

This research underlines the importance of mobility management tools and small-scale targeted interventions of public space upgrades in order to encourage conscious sustainable mobility behaviour. The paper reviews tools and tactics of soft transport policy measures, as well as of small-scale and low-cost public space design approaches and strategies in the USA and Europe to assess their characteristics and results. It will then focus on Thessaloniki (Greece) presenting 1) the main findings of a trip survey concerning the impact of the economic crisis on mobility behaviour and 2) the shift to low-cost street scale urban design projects which have emerged during the crisis. The paper states that quality public space and urban transport constitute conditions necessary to attain long-term change in mobility behaviour. While the importance of hard transport policy measures should not be underestimated, the strategy for achieving sustainable urban mobility and public space design adapted to the economic crisis-specific conditions is discussed. [ABSTRACT FROM AUTHOR]

Air pollution is one of the most important problems in big cities, resulting in adverse health effects. The aim of the present study was to characterize the personal exposure to indoor and outdoor pollution in the Greater Athens Area in Greece by taking measurements during a journey from suburban to mixed industrial–urban areas, encompassing walking, waiting, bus travel, and metro travel at various depths. For this reason, low-cost (LC) sensors were used, and the inhaled dose of particulate matter with an aerodynamic diameter of less than or equal to 2.5 μm (PM2.5) in different age groups of passengers was calculated. Specific bus routes and the Athens metro network were monitored throughout different hours of the day. Then, the average particulate matter (PM2.5) exposure for a metro passenger was calculated and evaluated. By considering the ventilation rate of a passenger, an estimation of the total PM2.5 inhaled dose for males and females as well as for different age groups was made. The results showed that the highest PM2.5 concentrations were observed inside the wagons with significant increases during rush hours or after rush hours. Furthermore, there should be a concern regarding older individuals using the subway network in Athens during rush hours and in general for sensitive groups (people with asthma, respiratory and cardiovascular problems, etc.). [ABSTRACT FROM AUTHOR]

In an epoch characterized by the swift pace of digitalization and urbanization, the essence of community well-being hinges on the efficacy of urban management. As cities burgeon and transform, the need for astute strategies to navigate the complexities of urban life becomes increasingly paramount. This study employs time series analysis to scrutinize citizen interactions with the coordinate-based problem mapping platform in the Municipality of Patras in Greece. The research explores the temporal dynamics of reported urban issues, with a specific focus on identifying recurring patterns through the lens of seasonality. The analysis, employing the seasonal decomposition technique, dissects time series data to expose trends in reported issues and areas of the city that might be obscured in raw big data. It accentuates a distinct seasonal pattern, with concentrations peaking during the summer months. The study extends its approach to forecasting, providing insights into the anticipated evolution of urban issues over time. Projections for the coming years show a consistent upward trend in both overall city issues and those reported in specific areas, with distinct seasonal variations. This comprehensive exploration of time series analysis and seasonality provides valuable insights for city stakeholders, enabling informed decision-making and predictions regarding future urban challenges. [ABSTRACT FROM AUTHOR]

Recent treatment of accommodation and arrival infrastructures for asylum seekers and refugees has fuelled international research on refugee reception policies in urban environments and on the consequences of related initiatives of the European Union and international organizations such as the UNHCR. Using Athens as a case study, this article provides empirical evidence to revive the theoretical treatment of the importance of arrival and accommodation infrastructures in urban areas in transition. We collected and compiled data from four sources: the 2011 population census, the 2018 ESTIA accommodation program and the UNHCR Site Management Support (SMS) Reports of Temporary Accommodation Sites and Reception and Identification Centres (RICs), and a primary survey of services for asylum seekers and refugees. After the geocoding of data, we calculate indices for key dimensions of the segregation of accommodated asylum seekers and foreign nationals. We discuss the findings, seeking to highlight how the location and the composition of accommodation infrastructures has been influenced by a wider process of urban change and adaptations to global forces, leading not only to the transformation of inner-city zones but also suburban and peri-urban areas. [ABSTRACT FROM AUTHOR]

This paper investigates the relative efficiency and productivity change of municipalities (regions of Thessaly and Central Greece), during the period 2012-2016. This period is rather special, because Greece had to meet the commitments imposed by the very tight fiscal consolidation program and, secondly, a major structural reform had preceded in Greek Local Government. It implements Data Envelopment Analysis (DEA) with output orientation and Malmquist analysis. Additionally, it estimates the effects of the environmental factors on the efficiency using Regression Analysis. The findings suggest that municipalities could produce on average the same quantity of inputs with 23.7% or 10.40% more quantity of outputs and on average refrain 14.90% from the optimal scale. The total factor productivity change has risen by an annual average of 0.6% relatively to the base year 2012. Moreover, the evaluation of municipalities on the basis of efficiency and productivity criteria and the identification of municipalities constituting benchmarks, contribute to policy formulation and regionbased approaches. [ABSTRACT FROM AUTHOR]

In this work the problem of change detection in high-resolution (HR) satellite images is addressed. The active learning (AL) algorithm Bayesian active learning disagreement (BALD) is applied on WorldView images of urban and suburban areas in the island of Crete, Greece. Comparisons with results from random sampling (RS) on AL are carried out. Several cases of selecting different amounts of images in the training set of a convolutional neural network (CNN) are experimented. The results show that the validation accuracy of classification as changed or unchanged of the BALD algorithm is superior to that of the RS algorithm. Indeed, the BALD algorithm achieves zero test error against the test errors 34.6% and 38.5% of the RS algorithm. Actually, as the amount of training images increases, the accuracy also increases. Interesting experiments could be executed in the future utilizing estimators from robust statistics inside the AL acquisition function framework. Up to now in the literature no other work has appeared to present deep AL on WorldView images for change detection. [ABSTRACT FROM AUTHOR]

The aim of this article is to investigate two external flexible forms of employment—the leasing of workers through Temporary Work Agencies (TWAs) and the contracted workers employed through Business Service Providers (contractors). Undoubtedly, these two forms of employment are complex and often give rise to confusion. First, this article reviews the characteristics of these types of workers and the operation of these businesses. Second, it presents the results of a mixed method of empirical research (quantitative and qualitative) regarding contracted workers. Our sample was 365 contracted workers from the cities of Athens, Thessaloniki and Patras, Greece. In particular, quantitative research is conducted using a methodology called RDS (Respondent Driven Sampling) that is innovative in the field of labour economics and labour relations. Some significant findings of our qualitative research are used to improve, extend, and interpret the quantitative results. Our research proves that contracted workers, who are employed at the premises of the banks, are leased workers, and the contracting undertakings usually operate unlawfully as TWAs. Our research proves that Banks in Greece are using "pseudo-contracting" to circumvent the European Directive 2008/104/EC and the Greek Laws 4052/2012 and 4254/2014, both of which provide institutional protection to workers leased through TWAs. In more detail, the relevant European Directive and the Greek Law 4052/2012 provide salary equality and equal labour rights for the leased workers in Greece and the EU, when they share the same qualifications as the permanent employees of the user undertakings. The employers' aim in adopting this policy is mainly to pay lower salaries to contracted workers, who in practice have the characteristics of leased workers. [ABSTRACT FROM AUTHOR]

Urban areas adjacent to wildlands are very dangerous zones for residents and their properties during a wildfire event. We attempted to connect wildfire simulations with field inventories and surveys to create a framework that can be used to enhance the fire resistance of residential structures located in the wildland-urban interface (WUI). Legal restrictions and the lack of economic incentives for WUI residents greatly limit the potential to appropriately intervene to enhance their property's fire resistance. By studying in situ the resilience of building materials and combining them with exposure metrics produced from wildfire simulations, we created an index that helps to assess fire risk at the property level. The proposed index can support property owners to optimally manage the vegetation near or inside their property. State agencies can use our proposed index to estimate with a consistent methodology which properties are more exposed and with higher risk from fire damage so that specific fuel and vegetation management practices on and around them can be suggested or enforced. [ABSTRACT FROM AUTHOR]

The aim of this study is to assess the resilience of coastal urban areas and their exposure to sea-level rise and coastal flooding, using the proposed Coastal Resilience Index (CResI). The CResI is an innovative combination of diverse characteristics. It includes 19 parameters and is implemented using GIS techniques. The parameters included in the CResI are classified into six category factors (geomorphology, flooding, wave exposition, land use, socioeconomic, and infrastructure/functional). The Analytic Hierarchy Process is used to assign weights and rank the parameters. The framework is tested in the southwest waterfront of the Athens Metropolitan Area in Greece. The study identified that around 25% of the coastal area could be at risk of coastal flooding in the upcoming years, including areas in both the metropolitan and suburban environments. As a result, the need for adaptation measures cannot be overlooked. [ABSTRACT FROM AUTHOR]

Sfakia is a mountainous municipality located in the southwestern area of the island of Crete, including the southern part of the Lefka Ori Mountain, with an elevation ranging from sea level to over 2400 m. The mountainous massif mainly consists of carbonate rocks and intense karstic phenomena can be observed. The part of the area exceeding over the elevation of 600 m is characterized by high amounts of precipitation (1500 mm). Despite this high precipitation, the water availability in the area is low. This work aims to identify the factors that affect the water-resources availability in this area. In addition, issues related to proper water management are presented and discussed that will allow areas with similar characteristics to adapt to climate change. Our study identified the complex geological setting of the area that redirects water away of the hydrological basin (karsts) and the geomorphology that favors precipitation loss through runoff as the most important factors for the low availability of water resources. This paper attempts to create a base of discussion for similar cases worldwide by providing a framework of approaching scientifically analogous problems. [ABSTRACT FROM AUTHOR]

This paper explores the role of mathematical models in archaeology and history. Variants of a particular model - an entropy-maximizing spatial interaction model which also functions as a location model - are presented through two case studies. The first is an example from Archaeology which throws light on settlement sizes in the 9th and 8th century BC Greece; the second is from History and explores the evolution of the United States' urban system from 1790-1870 with particular reference to the impact of railways. The approach is essentially interdisciplinary and uses concepts from Geography, Economics, Physics and Ecology. [ABSTRACT FROM AUTHOR]

The role of urban green areas in the microclimatic conditions of cities, during summer, is investigated in this paper through monitoring campaigns carried out at the National garden, at the city centre of Athens. Two types of investigations were carried out: i) a microscopic one that investigated the thermal conditions inside the Garden and the immediate surrounding urban area and ii) a macroscopic one that compared the temperature profile of the Garden with that of the greater city centre area. It was concluded that in microscopic level, the temperature profile inside the National Garden and the immediate surrounding urban area did not showed a clear evidence of the influence of the Garden and it was dependent on the characteristics of each location. In a macroscopic scale, the Garden was found cooler than the other monitored urban locations and temperature differences were mainly greater during the night, especially in streets with high building height to street width (H/W) ratio and low traffic, while in streets with high anthropogenic heat during the day, the biggest temperature differences were recorded during the day. [ABSTRACT FROM AUTHOR]

This paper argues that spatial contingencies, defined by the relationship between where historical actors are in the narrative and what they say, are crucial for understanding the political and ideological effects of Thucydides' "History." A comprehensive approach to these contingencies is linked to two related premises. First, that the city of Athens is the principal spatial referent in the "History" and, second, that Athens refers both to a set of "real" topographical features and to a transcendent and trans historical ideal that exceeds those features. The dynamic between these two is mediated by Athens' inevitable defeat and by the related conflict between the "History" as the presentation of facts about the past, on the one hand, and as the source of future predictions, on the other. Framing this analysis are the distinctive characteristics ascribed to the Athenians as a collective and to the positions of Thucydides and Alcibiades as Athenians in exile. [ABSTRACT FROM AUTHOR]

Since 2021, the prefectural authorities of the Attica Region in Greece have been operating a rewarding recycling program for the collection of clean recyclable waste in collaboration with the "Specialist Integrated Association of the Prefecture of Attica" (EDSNA, in Greek) and private contractors, called "THE GREEN CITY". This program mobilizes almost 30 mobile green points (MGPs) daily, which are self-propelled trucks that collect clean recyclable materials from citizens and businesses across the Attica Region. After one year of operation, this program has shown promising results, having more than 100,000 registered citizens and having already collected over 500 tons of clean recyclable municipal solid wastes in more than 60 municipalities of Attica. However, these promising results are accompanied by some significant financial and environmental costs. This study presents two different practical improvement scenarios for THE GREEN CITY recycling program's current situation that ensure (a) the shortening of the annual kilometers and time on the remote routes of all programs, (b) the annual fuel-cost decrease for the MGPs and (c) the annual reduction of their CO2 emissions into the atmosphere. Afterwards, we compare these two scenarios and conclude that the "first improvement scenario with main depot decentralization" is more realistic, feasible and has a bigger total sum of positive impacts than the second one. Therefore, this study strongly suggests the implementation of the "first improvement scenario with main depot decentralization" and opens the road to future improvement scenarios for various waste-management systems or recycling programs. [ABSTRACT FROM AUTHOR]

Image registration is among the most popular and important problems of remote sensing. In this paper we propose a fully unsupervised, deep learning based multistep deformable registration scheme for aligning pairs of satellite imagery. The presented method is based on the expression power of deep fully convolutional networks, regressing directly the spatial gradients of the deformation and employing a 2D transformer layer to efficiently warp one image to the other, in an end-to-end fashion. The displacements are calculated with an iterative way, utilizing different time steps to refine and regress them. Our formulation can be integrated into any kind of fully convolutional architecture, providing at the same time fast inference performances. The developed methodology has been evaluated in two different datasets depicting urban and periurban areas; i.e., the very high-resolution dataset of the East Prefecture of Attica, Greece, as well as the high resolution ISPRS Ikonos dataset. Quantitative and qualitative results demonstrated the high potentials of our method. [ABSTRACT FROM AUTHOR]

Historic school buildings, erected during the end of the 19th–beginning of the 20th century, represent a specific constructional type that should be encountered as part of the common European built heritage. They present various similarities, especially in the regions of S. Europe, even though they were mainly built with local materials following the traditional constructional principles of each area. Due to their constant function as educational units, there is an increased interest on their structural and energy integration, without, however, following the principles of restoration of historic structures. To this extent, the acknowledgement of the tangible and intangible values they encompass is crucial, as well as their enlistment in order to be treated as heritage assets. In this study, an effort has been made to testify the characteristics (historic, architectural, constructional) of the historic school buildings located in the Municipality of Agia, region of Thessaly, central Greece. A case study was selected, concerning the old elementary school of Megalovrysso, where a detailed investigation was implemented, including onsite inspection, architectural overview, determination of constructional materials and types, investigation of the preservation state, as well as structural analysis through the three-dimensional finite element model. All research data were comparatively evaluated in order to determine the principles governing the construction of the studied school buildings and establish the significance of this unrecognized part of European built heritage that should be further assessed. [ABSTRACT FROM AUTHOR]

In the past few years, the continuous expansion of urban development has created mixed forested, agricultural, and urban areas. These areas are called the wildland–urban interface (WUI), and they are characterized by increased human activities and land-use conversion, and they usually contribute to a high risk of wildfire occurrence. In the case of the peri-urban areas of Thessaloniki city, an effort was made to map, classify, and describe this wildland–urban interface, using Sentinel-2 satellite images of the area and very large scale orthophotos (VLSO) for the human settlements. Object-based image analysis (OBIA) was applied to classify landcover, combined with analysis of field data. The results showed that the WUI area in the city of Thessaloniki appears to the north and east of the city and covers an area of 2203.98 ha. The main characteristics affected by the ecological conditions of this area are the building (or human infrastructure) density, type, and the structure of forest vegetation. Human population pressure was found to be greatly differentiated between WUI areas belonging to different municipalities, the most affected was the municipality of Thessaloniki. A set of fire prevention silvicultural treatments are suggested for mitigating the fire danger in the area, accompanied by appropriate human awareness actions and the involvement of the local society. These measures include the reduction in crown bulk density and increase in crown base height through pruning (at least to 1/3 of total tree height), and low thinning, aiming to ensure that tree crowns of mature Pinus brutia trees are not in contact with one another. Both in the young P. brutia forest and the evergreen vegetation areas, thinning, pruning, and vegetation clearing is recommended adjusted according to each ecosystem. [ABSTRACT FROM AUTHOR]

Abstract: The latest developments in the field of energy supply, along with the major issue of the environment protection, set new priorities and yardsticks concerning the energy policies implemented worldwide. The development and implementation of effective energy conservation policies has been a target of the European Union ever since the days when it was still called European Economic Community. In this framework, and despite the successes already monitored, the need for further energy conservation in the building sector is a both an aim and a tool. Emphasis is being placed on the residential building stock and the improvement of its energy performance. Greece has been one of the last countries to adopt the Directive on the Energy Performance of Buildings. A thorough research regarding the nature of the Greek residential building stock helps in highlighting the problems associated with this delay, but also the perspectives for catching up with the other EU member states and achieving the aims set for the coming years. This paper aims at providing detailed information on the residential urban building stock, as determined in a field study in typical big and smaller Greek cities. [Copyright &y& Elsevier]

Abstract: In urban areas where there has been continuous occupation of the land for centuries, there are likely to be large areas of filled ground. Fills may have arisen inadvertently from the rubble of demolished buildings and the slow accumulation of refuse. Old urban fills of this type may contain soil, rubble, refuse and even whole parts of past constructions. Despite the fact that areas covered with such deposits are generally prone to severe problems, especially under conditions of dynamic loading, still their influence, as a foundation material on the seismic behaviour of modern buildings is practically unpredictable. Thessaloniki is an old historical city of Macedonia, Greece with no less than 2300 years of continuous urban evolution. A thick and heterogeneous layer of artificial deposits covers the biggest part of the historical centre of the city, as is the case for many old historical cities. The presence of this extensive formation influences the urban development, as it constitutes the foundation of the majority of the buildings of the historical centre, and its investigation is essential for most of the major constructions proposed. The complexity and heterogeneity of Thessaloniki''s fill makes the assessment of its engineering behaviour a rather complicated task. This is due to the big range of values of accumulated geotechnical data but also to the fact that these data have been produced by unrelated methods and applied tests. The aim of this paper is to assess the engineering performance of Thessaloniki''s fill based on its behaviour as foundation material to a major seismic event. This is carried out by the evaluation of the influence of engineering geological parameters to the damage distribution of the 1978 earthquake, based on the official database which recorded the condition of all the buildings of the historical centre. The statistical elaboration of the damage distribution was carried out following a classification scheme for the fill, based on the fill''s classes produced by this scheme, the fill''s thickness and the combination of both. The results are given in terms of damage ratios i.e. the ratios of the number of buildings in each damage status per total number of buildings inspected. The correlation of the engineering response with the thickness of the fill showed that there is a significant increase of the percentage of damaged buildings with increasing thickness. However, further analysis of these results showed that the above increase does not apply to all classes equally, which actually suggests that different parts of the fill behave differently in respect to the fill thickness. These results clearly show that a classification scheme and the determination of the boundary conditions should be used as a combined tool from an engineering geological point of view, in order to form a basis for the better understanding of the engineering behaviour of such deposits, the interpretation of geotechnical data and the design of more sophisticated investigations. [Copyright &y& Elsevier]

The ancient Persian empires are denoted as despotic, practicing arbitrary rule while Greece, Persia's archrival during the sixth to fourth century BC, exercised rule of law. This paper uses a contract theory framework to analyze some of the geographical and environmental underpinnings of the existence of rule of law in the city-states of ancient Greece and its absence in Persia. I discuss the role of geographical conditions of land (open plains versus mountains), population pressure, proximity to the sea and form of trade (overland versus overseas) as factors conducive to rule of law in the city-states of ancient Greece and to despotism in ancient Persia. Specifically, the role of trade via land in Persia prior to the fifth century BC is compared to the role of sea trade (alongside with piracy) in ancient Greece. I argue that in ancient Persia monarchs could tax or expropriate much of the gains from overland trade, preventing the accumulation of an independent form of wealth by merchants. In Greece, sea trade alongside the practice of piracy led to gains from trade that could not be easily expropriated by the monarchs and acted as a balancing force vis-a-vis the power of the monarchs, creating a basis for rule of law in the Greek city-states. [ABSTRACT FROM AUTHOR]

Abstract: In this paper, the OSPM model is employed for the calculation of the PM10 concentration levels in the historical centre of the city of Thessaloniki (Greece). Although measurements of the background concentration are available at a suburban station, and a few measurements of PM10 concentrations do exist at particular areas inside the historical city centre, further assumptions had to be made (e.g., for the traffic load) in order to implement OSPM. To validate this approach, NO x and NO2 measurements were employed in addition to data for PM10. The good agreement observed allowed the prediction of PM10 concentrations in all streets in the historical city centre. The very high PM10 concentration levels obtained in almost all streets are indicative of the city''s situation today. Finally, developments in vehicle''s technology are invoked to model possible future scenarios. [Copyright &y& Elsevier]

Abstract Urban geomorphology examines the conditions that lead to flooding problems in urban regions. Glyfada and Voula are located on the southwestern coast of Attica. Several times in the past catastrophic flooding events have taken place in these areas. This paper concerns the geologic and geomorphologic features, human intervention and its impact, along with their interaction. The locations with the highest vulnerability to flooding were registered. GIS processing served to present the results of this investigation. The relief of the region, the geologic and geomorphologic conditions, the stream flow features, the drying up of wetlands and lagoons, the elimination of vegetation cover, the urbanization of streams and the deficient draining networks, are the main causes of flooding generation in the study area. Some major suggestions dealing effectively with the problem are given. [ABSTRACT FROM AUTHOR]

In this study the accuracy of ALOS Global Digital Surface Model (AW3D30) with a point spacing of approx. 30-meter mesh was examined, taking as a case study several areas of Greece with complex geomorphologic characteristics. DSMs from ALOS stereo pairs were created using classical photogrammetric techniques. These DSMs were compared with the ALOS AW3D30 and a DEM created from digitized contours. Visual and statistical comparison of the DSMs has been performed.Check Points of known elevation selected from the National Trigonometric Network have been used to estimate the accuracy of the DSMs and the results are presented herein. It has been proved that the freely available AW3D30 DSM presents two or three times lower Root Mean Square Error (RMSE) than the respective DSMs from ALOS PRISM images. In areas with low relief such as Antiparos Island in the Cyclades complex, the ALOS AW3D30 RMSE is only 2.69 m, while in Areas with high relief such as the Chania Prefecture in Western Crete the respective error rises up to 14m. In urban area such as Athens, the capital of Greece, the respective error ranges around 12m due to the complex urban environment (high buildings, narrow urban roads, moving vehicles etc.). [ABSTRACT FROM AUTHOR]

Constant urban population growth and intensive urbanization lead to increased pressure on urban areas leading to uncomfortable living conditions. The quality of urban living conditions often depends on the thermal comfort of the open urban spaces, which are used on the daily basis. That is the reason why the attention towards outdoor thermal comfort (OTC) is increasing in the last decade among the researchers from different fields of expertise. In this article, the review of the outdoor thermal comfort research in urban areas of 11 countries of Central and Southeast Europe in the last decade (2010-2019). The main aim of the review is to give a comprehensive, systematic and complete insight in the current situation in the OTC research interest. The results of the review show increased but uneven interest in outdoor thermal comfort by the end of the research period in countries of the Central and Southeast Europe. In total, 120 articles on the topic of outdoor thermal comfort were identified in the research area. The most significant contribution to the urban outdoor thermal comfort research comes from Hungary, Serbia and Greece. Furthermore, five research objectives were identified: methodology improvement and development, climate sensitive and comfortable urban design and planning, citizens/pedestrian comfort and health assessment and improvement, tourism and health sector support and literature review. [ABSTRACT FROM AUTHOR]

Urban regions are the driving forces of Europe's economic development, they are centres of creativity and innovation and also, they are the factor of the achievement of "Europe 2020" strategy. During 2014 - 2020 programming period, urban dimension was at the centre of Cohesion Policy. New European Union's (E.U.) policy seeks to cultivate complete urban policies that enhance Sustainable Urban Development (S.U.D.) in order to enhance cities' ability of adjustment and ensure investments. According to Partnership Agreement (P.A.) 2014 - 2020, S.U.D. is a new tool for territorial development which aims to provide a way out of the social, economic and environmental problems of the degraded urban regions and an alternative answer to the consequences of crisis. S.U.D. may be implemented either through Integrated Territorial Investments (I.T.I.) or through local development after initiative of local communities. I.T.I.s are the tool for planning and implementation of complete territorial strategies and they may be financed from European Social Fund (E.S.F.), European Regional Development Fund (E.R.D.F.) and Cohesion Fund. The competent bodies that take over the preparation and implementation of I.T.I. are the managing authorities, urban authorities, intermediate bodies, and the Strategic Planning and Evaluation Special Service. This Study analyses the current situation of Piraeus municipality and I.T.I.s' strategy for S.U.D. that will be implemented in the municipality. Piraeus municipality is the greatest industrial centre in Greece and it has the largest port in Europe. However local authorities so far have not managed to highlight and exploit the comparative advantages available to the municipality. I.T.I.s aim to enhance entrepreneurship and social cohesion, improve financial situation and protect the already burdened environment. The statistical survey was based on the construction of a questionnaire addressed to 116 employees of the municipality of Piraeus. The correlation between the S.U.D. of Piraeus municipality and the socio-demographic factors was investigated through multi-factorial linear regression models, checking for possible confusing factors. [ABSTRACT FROM AUTHOR]

Mitigation plans to counteract overheating in urban areas need to be based on a thorough knowledge of the state of the thermal environment, most importantly on the presence of areas which consistently demonstrate higher or lower urban land surface temperatures (hereinafter referred to as "hot spots" or "cold spots", respectively). The main objective of this research study is to develop a methodological approach for the recognition of thermal "hot spots" and "cold spots" in urban areas during summer; this is accomplished with (a) the combined use of high and medium spatial resolution satellite data (Landsat 8 and Terra-MODIS, respectively); (b) the downscaling of the Terra-MODIS satellite data so as to acquire spatial resolution similar to the Landsat one and at the same time take advantage of the high revisit time as compared to the respective one of Landsat (16 days); and (c) the application of a statistical clustering technique to recognize "hot spots" and "cold spots". The methodological approach was applied as a case study for the urban area of Athens, Greece for a summer period. Results demonstrated the capacity of the methodological approach to recognize "hot spots" and "cold spots", revealed a strong relationship between land use and "hot spots" and "cold spots", and showed that the average land surface temperature (LST) difference between the "hot spots" and "cold spots" can reach 9.1 °K. [ABSTRACT FROM AUTHOR]

The Ozone Fine Structure Model (OFIS) model allows an adequate description of urban photochemistry at a very low computational effort. Thus, it may be used for statistical analyses of urban scale ozone levels, including the assessment of control strategies and exposure estimates. Recent model extensions allow taking properly into account emission inhomogeneities in the surroundings of the considered city and local circulation systems. The performance of both the standard and the extended OFIS model versions is illustrated by its application to Stuttgart and Athens. The results reveal that the model extensions allow for more versatility in inhomogeneous situations. [ABSTRACT FROM AUTHOR]

We analyse the earthquakes catalogues for Italy, South California, and Greece across the COVID-19 lockdown period for each country. The results for Italy and Greece show that, even if the reduction of the signal to noise ratio has improved the earthquake detection capability, the completeness magnitude remains substantially unchanged, making the improved detection capability ineffective from the statistical point of view. A slight reduction (0.2) of the completeness magnitude is observed for South California, likely related to the relatively higher number of seismic stations located close to urban areas. Our findings suggest that—given the present configuration of the seismic network considered here—only an important decrease in the station spacing can produce a significant decrease of the completeness magnitude. [ABSTRACT FROM AUTHOR]

Fluvial floods are one of the primary natural hazards to our society, and the associated flood risk should always be evaluated for present and future conditions. The European Union's (EU) Floods Directive highlights the importance of flood mapping as a key stage for detecting vulnerable areas, assessing floods' impacts, and identifying damages and compensation plans. The implementation of the EU Flood Directive in Greece is challenging because of its geophysical and climatic variability and diverse hydrologic and hydraulic conditions. This study addressed this challenge by modeling of design rainfall at the sub-watershed level and subsequent estimation of flood design hydrographs using the Natural Resources Conservation Service (NRCS) Unit Hydrograph Procedure. The HEC-RAS 2D model was used for flood routing, estimation of flood attributes (i.e., water depths and flow velocities), and mapping of inundated areas. The modeling approach was applied at two complex and ungauged representative basins: The Lake Pamvotida basin located in the Epirus Region of the wet Western Greece, and the Pinios River basin located in the Thessaly Region of the drier Central Greece, a basin with a complex dendritic hydrographic system, expanding to more than 1188 river-km. The proposed modeling approach aimed at better estimation and mapping of flood inundation areas including relative uncertainties and providing guidance to professionals and academics. [ABSTRACT FROM AUTHOR]