Light pollution is a type of pollution that climaxes in cities and occurs increasingly away from them, due to the increase of artificial lighting and inappropriate lighting design (selection of luminaires, aiming, illuminance/luminance levels, and spectral characteristics). Increasingly, light pollution also affects the countryside due to local lighting but also distant lighting propagating from urban areas. This has a significant impact on ecosystems and astronomical observing sites. This work analyzes the main facts about light pollution (causes, impact, and solutions) and studies the methods, parameters, and special requirements for planning of light pollution protected areas. This dark sky park planning methodology is implemented as a case study in mount Parnon which has been selected due to its significance as a Natura 2000 protected area and because it is Greece’s most popular astronomical observing site. Mount Parnon is located close to two major cities as well as significant highways, however the site itself remains dark due to its sparse population. Planning a dark sky park involves a complete study of facts regarding the specific site. Existing lighting installations are surveyed in detail by recording types of luminaires and lamps and recording their positions in a map. Lighting illuminance levels are measured by photometers and spectra are analyzed using a spectrometer. Sky brightness levels measurements are performed using specialized photometers and light pollution origins are traced using wide-field photography. Finally, a proposal is made for a dark sky park scheme suited to the specific case of the site.

Distributed smart camera systems are becoming increasingly important in a wide range of applications. As they are often deployed in public space and/or our personal environment, they increasingly access and manipulate sensitive or private information. Their architectures need to address security and privacy issues appropriately, considering them from the inception of the overall system structure. In this paper, we present security and privacy issues of distributed smart camera systems. We describe security requirements, possible attacks, and common risks, analyzing issues at the node and at the network level and presenting available solutions. Although security issues of distributed smart cameras are analogous to networked embedded systems and sensor networks, emphasis is given to special requirements of smart camera networks, including privacy and continuous real-time operation.

This work presents the concept and methodology as well as the architecture and physical implementation of an integrated node for smart-city applications. The presented integrated node lies on active RFID technology whereas the use case illustrated, with results from a small-scale verification of the presented node, refers to common-type waste-bins. The sensing units deployed for the use case are ultrasonic sensors that provide ranging information which is translated to fill-level estimations; however the use of a versatile active RFID tag within the node is able to afford multiple sensors for a variety of smart-city applications. The most important benefits of the presented node are power minimization, utilization of low-cost components and accurate fill-level estimation with a tiny data-load fingerprint, regarding the specific use case on waste-bins, whereas the node has to be deployed on public means of transportation or similar standard route vehicles within an urban or suburban context.

This paper presents a multifunctional circuit realizing the functions of oscillation, mixing, amplification, and frequency multiplication at 5 GHz. A theoretical and experimental description of the circuit is given. The proposed circuit, which combines both the injection-locking and mixing processes, uses only one port where both the RF/intermediate frequency signal and the injection signal (IS) are applied. The IS, which is used to stabilize the oscillation, is at a subharmonic of the oscillation frequency (omega_osc/4) having a power level as low as -50 dBm. Calculations of the phase noise and measurements of the mixing properties are reported which indicate a noise improvement, and a high up-conversion gain. The implementation of the circuit exhibits an up-conversion gain of 14 dB, a phase noise of -110 dBc/Hz at 100-kHz offset, a dB of -15 dBm, a third-order intercept point of -2 dBm, and a power consumption of 35 mW. Calculated and measured results are in good agreement for all cases, emphasizing the relevance of the proposed circuit.

Dynacargo, a research project under implementation, aims to change supply chain management, as the hauled goods are at the center of attention instead of vehicles, as in traditional management approaches. At the same time Dynacargo manages both delivery and collection cycles. Dynacargo aims at developing a near real-time monitoring system that monitors and transmits waste bins' fill level, which is used to dynamically manage the waste collection process by introducing distance minimization, relying on efficient routing algorithms. This paper deals with research issues that have emerged along with developments regarding specific architectural modules. In general, Dynacargo places a set of durable, low cost sensors and RFID tags on waste bins. These tags store the fill-level estimated by the sensors, which is passed through diverse communication channels and ends to a central cargo information management system. Along with this real time data harvesting, data mining techniques are utilized on historical data collected prior to Dynagargo implementation, in order to predict future waste bins fill rates. Mobile and web applications are developed in order to harvest relevant data from citizens.

This work presents the architecture, modelling, simulation, and physical implementation of a versatile, scalable system for use in common-type waste-bins that can perform and transmit accurate fill-level estimates while consuming minimal power and consisting of low-cost embedded components. The sensing units are based on ultrasonic sensors that provide ranging information which is translated to fill-level estimations based on extensive simulations in MATLAB and physical experiments. At the heart of the proposed implementation lies RFID technology with active RFID tags retrieving information and controlling the sensors and RFID readers receiving and interpreting information. Statistical processing of the simulation in combination with physical experiments and field tests verified that the system works accurately and efficiently with a tiny data-load fingerprint.