City Of Xanthi Research Articles

Semantic Communities from Graph-Inspired Visual Representations of Cityscapes

The swift development of autonomous vehicles raises the necessity of semantically mapping the environment by producing distinguishable representations to recognise similar areas. To this end, in this article, we present an efficient technique to cut up a robot’s trajectory into semantically consistent communities based on graph-inspired descriptors. This allows an agent to localise itself in future tasks under different environmental circumstances in an urban area. The proposed semantic grouping technique utilizes the Leiden Community Detection Algorithm (LeCDA), which is a novel and efficient method of low computational complexity and exploits semantic and topometric information from the observed scenes. The presented experimentation was carried out on a novel dataset from the city of Xanthi, Greece (dubbed as Gryphonurban urban dataset), which was recorded by RGB-D, IMU and GNSS sensors mounted on a moving vehicle. Our results exhibit the formulation of a semantic map with visually coherent communities and the realisation of an effective localisation mechanism for autonomous vehicles in urban environments.

Urban Heat Island and Thermal Comfort Assessment in a Medium-Sized Mediterranean City

One of the greatest issues nowadays is that of the urban heat island effect on the thermal conditions inside cities. The air temperature inside the city core is warmer than that in suburbs, thus deteriorating the quality of life for citizens and making outdoor spaces uncomfortable in terms of thermal comfort. This phenomenon is usually assessed in large scale cities worldwide and less often in medium-sized towns. The current study aimed to investigate the urban heat island effect and, therefore, to assess the outdoor thermal comfort conditions in a medium-sized city. More specifically, the methodology of the current study includes: (i) the combination of different monitoring techniques to quantify the urban heat island effect in a medium-sized Mediterranean city. Both in situ measurements and remote sensing techniques were applied to assess the urban heat island effect in terms of both the canopy layer (CUHI) and the surface (SUHI); (ii) the identification of the parameters that affect thermal comfort and the identification of the most appropriate bioclimatic indices that determine outdoor thermal comfort in the city of interest. Both questionnaire survey and in situ measurements took place on a sidewalk in the city of Xanthi, Northern Greece, during the summer. The CUHI effect was obvious, especially in the morning and afternoon. Downscaled MODIS satellite images also showed that the intensity of SUHI was higher in the morning and afternoon. Apart from air temperature, important differences in the values of most microclimatic parameters were recorded between the meteorological station placed inside the urban area and those gathered from a nearby meteorological station. The narrow roads, the thermal properties of construction materials, and the absence of greenery characterized the area of interest and may be the key factors creating these differences in climate. Concerning the thermal comfort assessment, the most significant parameters were the air temperature and solar radiation, although, both empirical and direct indices were found to describe the comfort values well. According to the results, downscaling techniques are also important for the SUHI effect to be investigating in detail in medium-sized urban environments.

Experimental Investigation of Thermal Bridges and Heat Transfer through Window Frame Elements at Achieving Energy Saving

Windows are responsible for significant amounts of energy loss through typical building envelopes. There have been multiple studies on heat loss through the glazing unit and frame system. This study presents an experimental investigation of a window unit and focuses specifically on the conductance between the structural elements and the frame system of a conventional house in the city of Xanthi, northern Greece. It is obvious that even a perfect window system cannot reduce heat transfer between the base of the frame and the upper surface of the floor. The experimental and simulation procedure of this project includes the installation of an insulating layer in front of the window unit for a variety of frames (solid wood, aluminum, PVC, etc.) at different distances. The main objective of this paper is to determine how effective an insulating barrier can be in respect to different types of frame, glazing, and weather conditions for the control of heat loss. Through the application of this technique, in combination with an appropriate insulating frame and window unit, designers can control the temperature inside the room at close proximity to the windows, in order to contribute to energy saving, aiming towards a building with zero energy demand.

Hybrid Fuzzy Multi-Criteria Analysis for Selecting Discrete Preferable Groundwater Recharge Sites

This study proposes a hybrid fuzzy multi-criteria methodology for the selection of the most preferable site for applying managed aquifer recharge (MAR) systems by utilizing floodwaters. The use of MAR can increase water resources for later water utilization in case of drought. In this multi-criteria problem, seven recharge sites are under consideration, based on nine criteria, aiming to make a final list of their relative ranking. A fuzzy analytic hierarchy process (FAHP) based on the logarithmic fuzzy preference programming (LFFP) method is used to determine the weights of criteria. LFFP is an optimization-based method that produces a priority vector from a fuzzy pairwise comparison matrix. Furthermore, fuzzy inference systems (FIS) based on the Mamdani approach are used to estimate the rating of each alternative with respect to the criterion examined, and then the final evaluation of the alternatives is obtained. A FIS is a fuzzy if–then rule-based system where the experts’ qualitative knowledge is translated into numerical reasoning for each individual criterion. The proposed methodology is applied in the aquifer system of the agricultural plain located to the southeast of the city of Xanthi in the Prefecture of Xanthi, NE Greece.

Enabling Optimal Energy Management with Minimal IoT Requirements: A Legacy A/C Case Study

The existing literature on energy saving focuses on large-scale buildings, wherein the energy-saving potential is substantially larger than smaller-scale buildings. However, the research intensity is significantly less for small-scale deployments and their capacities to regulate energy use individually, directly and without depreciating users’ comfort and needs. The current research effort focused on energy saving and user satisfaction, concerning a low-cost—yet technically sophisticated—methodology for controlling conventional residential HVAC units through cheap yet reliable actuation and sensing and auxiliary IoT equipment. The basic ingredients of the proposed experimental methodology involve a conventional A/C unit, an Arduino microcontroller, typical wireless IoT sensors and actuators, a configured graphical environment and a sophisticated, model-free, optimization-and-control algorithm (PCAO) that portrays the ground basis for achieving improved performance results in comparison with conventional methods. The main goal of this study was to produce a system that would adequately and expeditiously achieve energy savings by utilizing minimal hardware/equipment (affordability). The system was designed to be easily expandable in terms of new units or thermal equipment (expandability) and also to be autonomous, requiring zero user interventions at the experimental site (automation). The real-life measurements were collected over two different seasonal periods of the year (winter, summer) and concerned a conventional apartment in the city of Xanthi, Northern Greece, where summers and winters exhibit quite diverse climate characteristics. The final results revealed the increased efficiency of PCAO’s optimization in comparison with a conventional rule-based control strategy (RBC), as concerns energy savings and user satisfaction.

Door-to-door recyclables collection programmes: Willingness to participate and influential factors with a case study in the city of Xanthi (Greece).

The implementation of a recyclable waste management system is a serious challenge for a society that aims to contribute to sustainability. The first operational step of such system is waste collection. In a number of European countries, the solid waste collection system has changed from the conventional kerbside system to a door-to-door collection. However, this type of waste collection system has not yet been introduced in Greece and its public acceptance prior to potential full implementation needs to be considered. This study aims to investigate the willingness of the residents of a Greek city (Xanthi, Thrace) to change from the existing kerbside collection system and initiate and participate in a door-to-door recyclable waste collection system instead. A questionnaire was designed and distributed randomly to 150 residents of Xanthi and a statistical analysis was then performed to assess the influence of a number of explanatory variables on recycling behaviour and the willingness to participate in a door-to-door collection system. The findings of this study indicate that most of the respondents (72.7%) were willing to participate in a future door-to-door recyclables collection programme in Xanthi. The factors that influenced the respondents' attitude with regard to such a programme were associated with level of education, their beliefs about the effectiveness of the current recycling system and also their attitudes towards recycling issues in general. Age and religion significantly affected recycling frequency. The survey and statistics presented in this article can be used as a model to assess the behaviour of citizens towards recyclable waste management systems worldwide.

Exploring the Effects of University Campus Decentralization to Students’ Mode Choice

Mobility patterns and travel behavior aspects of students traveling to universities, are gaining attention, as the completion of such every day trips are rather complicated. University students form a social group, essentially autonomous in terms of mode choice decision making. Understanding the mode choice decision process, may reveal the most appropriate interventions for achieving sustainable transport goals. The current study aims to examine various aspects of university students’ travel bahaviour such as travel distance, travel time, comfort and safety in the city of Xanthi, Greece. Moving a step forward, the paper provides a better understanding of students’ travel patterns in two different environments due to the University relocation from an urban environment to a more isolated one. For this purpose, a questionnaire survey is conducted where students describe their travel habits before and after the relocation. In addition, students are given a choice set comprised of eight different factors hypothesized to internalize the effect of the relocation on mode choice for the trips to and from the University and they are asked to prioritize them ranking them from the most significant one to the least important. For the analysis two Multinomial Logit models are developed. The results verify initial considerations; distance and time are the most important factors for both cases while the use of public transport instead of walking increases the importance of economy and safety.

Simulation of strong ground motion on near-fault rock outcrop for engineering purposes: the case of the city of Xanthi (northern Greece)

We combine probabilistic and deterministic approaches in an attempt to tackle a challenging topic in engineering seismology, that of the prediction of strong ground motion in urban areas located close to active faults, with sparse modern seismicity. The case we study is the city of Xanthi in northern Greece and we generate bedrock synthetic time series to be used as input motions into site-specific site effect analysis. We re-assess the seismic hazard using the probabilistic method and then perform hazard deaggregation in order to define realistic earthquake scenarios, which we examine in a deterministic way. The scenarios examined are: (a) a reference earthquake of M6.7, return period 100 years and at ~30 km distance from the city and (b) a reference earthquake of M5.8, return period 475 years and at ~3 km distance from the city of Xanthi. To compute synthetic time series for the distant source, we apply the stochastic method for finite faults. For the near-fault earthquake scenario we adopt a hybrid deterministic-stochastic approach that includes the semi-analytical method implemented in the COMPSYN code for the low frequency (~ 3 Hz). The results of the probabilistic and the deterministic approaches converge to a satisfactory degree.

Evidence of complex site effects and soil non-linearity numerically estimated by 2D vs 1D seismic response analyses in the city of Xanthi

This study discusses the effects of local site conditions on earthquake ground motion for city of Xanthi, North-Eastern Greece, focusing on the influence of complex site effects and soil non-linearity. Although city of Xanthi is characterized as a low seismicity area, documented strong earthquake events of past centuries indicate the necessity of an appropriate estimation of ground surface motion of the region. Therefore, a typical 2D cross-section along the city following an E-W direction is constructed, based on the synthesis of available geological, geotechnical and geophysical data of the broader area. 1D and 2D numerical models are generated utilizing the Finite Difference Method and site response is investigated for different seismic scenarios. Wave amplification is captured as a result of 1D resonance phenomena integrated with potential 2D complex wave effects, due to lateral propagation of the locally generated at the discontinuities surface waves. The additional, relatively to 1D, 2D amplification or de-amplification of ground shaking, in terms of its amplitude and its spectral content is quantified. The impact of soil deposits non-linearity on amplification level, as well as, on generated 2D wave fields is considered by implementing both equivalent-linear and non-linear approaches. The results reveal that, across the city, spatial variation of ground surface motion is obvious, attributed primarily to the variation of subsurface soil profiles. 2D wave effects have been generated signifying that, at particular site locations, ground motion is additionally amplified or de-amplified with respect to 1D response. However, 2D versus 1D differentiation has been calculated of ±20% in terms of PGA and spectral accelerations up to 1.0s, in the majority of the examined sites, implying that site response even though, influenced by 2D resonance phenomena, could be sufficiently captured by an 1D approach. Moreover, it is shown that if soil non-linearity is properly accounted for, it may play an important role on the estimated ground response, since non-linear approach seems to produce lower amplification levels with regard to 1D and 2D equivalent-linear approaches. As a general trend across the investigated site, for the entity of the various scenarios, the numerically calculated response spectra exceed EC8 seismic code provisions.

Investigation of Consumer Behavior

Evidence shows that sustainability not only helps a business case getting stronger, but also embraces a sustainability agenda which can stimulate innovation, pushing companies to rethink their operations, products and business models. In addition, during the past few years the demand for organic wine has increased and many Greek businesses have entered the market, advertising the superiority of organic wine. The main objective of this study is to portray the need for an implementation of new technologies in the distribution and supply of organic wine in the city of Xanthi. Furthermore, the investigation of consumers' attitude will constitute the basis for further development of business strategies regarding sustainability and innovation in the agri-food chain. From the quantitative and qualitative data, the statistical analysis will provide findings on consumer behavior, attitudes, new trends, and factors that affect the choice of organic wine. Finally, the current paper is indicative of the general consumer stance towards organic-products.

Surface temperatures of public buildings, built in 1880, 1970 and 2002, in Northern Greece

The purpose of this paper is to investigate the surface temperatures of the shelter of three public buildings in the city of Xanthi, in northern Greece. The buildings were built in different time periods and consequently they have different technical characteristics. Respectively, we survey the three following buildings that have been built in 1880 (Municipality Hall of Xanthi), in 1970 (Municipality Amphitheatre) and in 2002 (Bank offices building). Data have been gathered by the use of thermal camera and the survey has been conducted from January up to July. The data gathered regard measurements of the surface temperature of the exterior walls of the shelters, both inside and outside. The study aims at the evaluation of the thermal behavior of the shelter of buildings, which built in different time and under different regulations. The gathered data of the surface temperatures compare the different thermal behavior of the shelter. The analysis of the results and diagrams show that the thick masonry of the traditional Municipality Hall offers an insulation that is adequate. The building of 1970, which was constructed with the previous buildings regulation, has thermal losses due to inadequate insulation. The new building of 2002 has low thermal losses. The energy saving in the buildings and the implementation of environmental and bioclimatic design solutions are contemporary subjects of analysis and research. The main aim of energy efficiency buildings is to reduce the energy consumption and to ensure comfort thermal conditions in the buildings. A major number of the buildings of the Greek urban centers have been built at previous decades without specific constructive techniques for energy losses reduction of the building's shell. Nowadays, the new version of the contemporary technical regulations focuses upon the improvement of the energy efficiency of older buildings (change of frames, improve the insulation) and to design new buildings of low energy consumption.

Design, Operation and Economic Analysis of Autonomous Hybrid PV-Diesel Power Systems Including Battery Storage

Design, Operation and Economic Analysis of Autonomous Hybrid PV-Diesel Power Systems Including Battery Storage This paper presents a systematic techno-economic analysis of autonomous PV-Diesel energy system with battery storage. This hybrid type power system was developed and installed on the roof of the Electrical Engineering Laboratory building in the city of Xanthi, Greece, where a weather station is also installed providing necessary meteorological data since 2002. Such system can be generally used to supply electrical loads of isolated remote areas. The actual design of such a system is based on: a pre-defined load pattern to be supplied; the pertinent weather data; the relevant market prices; and the applicable recent economic rates (eg June 2009 for the Greek case). The system is operated on a predictive manner using a Programmable Logic Controller (PLC) which controls the main system parameters for safe and continuous power supply to meet reliably the desired load demand. Three distinct systems of this type and of equal capacity, which combine energy sources and battery storage have been proposed and assessed technically and economically.

Energy management in buildings: A systems approach

AbstractSystems approach is used to enhance the energy performance of an existing building by holistically examining it as a ‘‘sociotechnical’’ system. A student dormitory in the city of Xanthi, Greece, is used as a case study to identify the most appropriate interventions according to the principles of sustainability. In this context, a framework is developed that could be extensively used for energy management of existing buildings as well as of new ones. The ‘‘system methodology’’ of this framework breaks through the limited scope of engineering analysis and emerges as the only available tool to implement the principles of sustainability. © 2008 Wiley Periodicals, Inc.

On 3D reconstruction of the old city of Xanthi. A minimum budget approach to virtual touring based on photogrammetry

Abstract The old city of Xanthi (Thrace–Greece) is one of the biggest traditional settlements in Greece which has the specialty to exhibit mixed traditional Greek, European and Oriental architectural features. This paper presents a 3D reconstruction of a small part of the settlement. It deals with the idea of using open source systems in 3D graphics in order to produce realistic virtual walkthroughs for culture heritage promotion with a minimum budget and low cost infrastructure.

Characterization of Rain and Roof Drainage Water Quality in Xanthi, Greece

Thirteen field campaigns were undertaken in the period from December 2,2002 until September 1,2004 to collect water samples in order to characterize the quality of rainfall and roof drainage in the city of Xanthi, a typical provincial city in Greece. In each campaign, water samples were collected from 10 representative sites in the city (in total 130 samples), representing areas of distinct land use and human activities (i.e., traffic volume, residence density and industrial activity). The water samples were analyzed according to drinking water criteria for total coliform (not detected), temperature (range: 0.9-20 degrees C), pH (range: 3.6-11.4), alkalinity (range: 0-21.5 mg CaCO(3)/L), nitrate (range: 0-2456 microg/L), ammonium (range: 0-2628 microg/L), sulfate (range: 0-0.5 mg/L), calcium (range: 259.1-3064 microeq/L), magnesium (range: 0.8-488.8 microeq/L), potassium (range: 0.0-110.6 microeq/L) and dissolved heavy metals (Fe, range: 0.01-0.18 mg/L; Mn, range: 0.01-0.09 mg/L; Zn, range: 0.01-0.54 mg/L; Cu, Cr and Ni, not detected). Pollutant concentrations were generally higher in roof drainage than in rainwater, but both were lower than drinking water standards. Dissolved heavy metal concentrations were generally higher in the areas of intensive human activities, such as roads with high traffic volume and densely populated residential areas. The satisfactory quality of rainwater, which results from this analysis, makes its use as grey water possible.

Manos Hadjidakis: The Story of an Anarchic Youth and a "Magnus Eroticus"

Manos HadjidakisThe Story of an Anarchic Youth and a "Magnus Eroticus" Yiannis Miralis The name of Manos Hadjidakis is probably unknown to contemporary musicians and music educators. After all, the Greek composer achieved his international fame back in 1961 when he won an Oscar for his soundtrack of the movie, "Never on Sunday." Numerous other awards followed from England, France, Germany, and of course, Greece. After his six years in New York City (1966-1972), the composer returned to Greece where he produced a wealth of diverse musical work and had a profound impact on every aspect of Greek cultural life. Through his radio lectures, the notes on the covers of his records, and his articles in a variety of magazines and newspapers, he expressed his often radical ideas without any fear, but with honesty and passion. His commentaries covered a wide variety of topics such as music, poetry, and the arts, politics and nationalism in art, music education, tradition and change, and the overall cultural problems and dilemmas of his time. The magnitude of his musical and artistic work is yet to be fully discovered and appreciated. In this paper, I will provide a biography of Manos Hadjidakis with a closer [End Page 43] examination and description of his multifaceted work. Through this attempt, a better understanding of who Hadjidakis was and the impact that he had on the musical and cultural life of modern-day Greece will emerge. I decided to use numerous direct quotes from Hadjidakis' books and interviews not only because he eloquently expresses his thoughts and ideas, but also because through these quotes one can get a clear sense of his humor, intellect, and personality. This paper may also serve as food for thought for music educators in and outside of Greece. I say this because much of his work and thought remains unknown to the general public, as well as to music performers and educators. Unfortunately, to some extent this is true even in his own home country of Greece. Even though Hadjidakis was not a music educator in the specific sense of the term, many of the things that he fought for and achieved in his life had an identifiable educational component in them. For example, before each of the performances of the Orchestra of Colors that he founded and conducted, Hadjidakis always gave elaborate lectures on the composers and on the works to be performed at the amphitheatre of the Medical School of the University of Athens. Overall, if we use the Oxford English Dictionary's definition of "education" as "culture or development of powers, formation of character, as contrasted with the imparting of mere knowledge or skill,"1 Hadjidakis can be regarded as a true educator and many of his ideas have a direct implication for music education and education in general. This is what I will examine in the second part of this paper, focusing especially on his ideas on Eros and the importance of song. Hadjidakis' Childhood Hadjidakis was born on October 23, 1925 in the city of Xanthi in northern Greece. The city was thriving due to the local cultivation and sale of tobacco. His father was a tobacco merchant and his family was initially well off and able to pay for his piano lessons. After the death of his father in 1931, when Hadjidakis was only six years old, the family moved to Athens where he attended high school at nighttime, while working various jobs during the day. During World War II Hadjidakis became involved in a number of political organizations and simultaneously took lessons in diction in order to realize his dream of becoming an actor. However, because he had difficulty pronouncing the letter "r," he had to turn his attention and creativity away from acting and in a different direction. Additionally he received some formal training in classical music, but according to his own words, [m]y relationships with formal music studies were extremely similar to my relationships with dentists; I always approached them and always left them before the end of the treatment. When I was eighteen years old I gave up [End Page 44] music and I surrendered myself to poetry. When...

03/01875 Evaluation of the 200 MWe Tonghae CFB boiler performance with cyclone modification: Lee, J-M. et al. Energy, 2003, 28, (6), 575–589

This paper reports the technical feasibility and economic viability of a hybrid solar/wind grid connected system for electrical and thermal energy production, covering the energy demand of a typical residence in the city of Xanthi (Greece). The technical characteristics of the solar and wind energy subsystems are given. The energy output provided by the hybrid energy system was estimated using a simulation program, which is based on the Monte Carlo method, for reading the solar radiation and wind potential data. The auxiliary energy supply is based on the output of a combined-cycle natural gas power plant, recently constructed in the Thrace region. The economic analysis of the proposed hybrid solar/wind system is performed using the life cycle savings (LCS) method and the payback period (PBP) of the initial capital cost is determined.

Technoeconomic assessment of a hybrid solar/wind installation for electrical energy saving

This paper reports the technical feasibility and economic viability of a hybrid solar/wind grid connected system for electrical and thermal energy production, covering the energy demand of a typical residence in the city of Xanthi (Greece). The technical characteristics of the solar and wind energy subsystems are given. The energy output provided by the hybrid energy system was estimated using a simulation program, which is based on the Monte Carlo method, for reading the solar radiation and wind potential data. The auxiliary energy supply is based on the output of a combined-cycle natural gas power plant, recently constructed in the Thrace region. The economic analysis of the proposed hybrid solar/wind system is performed using the life cycle savings (LCS) method and the payback period (PBP) of the initial capital cost is determined.