ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    Publication Date: 2016-07-23
    Description: With the growing demand of Intelligent Transportation Systems (ITS) for safer and more efficient transportation, research on and development of such vehicular communication systems have increased considerably in the last years. The use of wireless networks in vehicular environments has grown exponentially. However, it is highly important to analyze radio propagation prior to the deployment of a wireless sensor network in such complex scenarios. In this work, the radio wave characterization for ISM 2.4 GHz and 5 GHz Wireless Sensor Networks (WSNs) deployed taking advantage of the existence of traffic light infrastructure has been assessed. By means of an in-house developed 3D ray launching algorithm, the impact of topology as well as urban morphology of the environment has been analyzed, emulating the realistic operation in the framework of the scenario. The complexity of the scenario, which is an intersection city area with traffic lights, vehicles, people, buildings, vegetation and urban environment, makes necessary the channel characterization with accurate models before the deployment of wireless networks. A measurement campaign has been conducted emulating the interaction of the system, in the vicinity of pedestrians as well as nearby vehicles. A real time interactive application has been developed and tested in order to visualize and monitor traffic as well as pedestrian user location and behavior. Results show that the use of deterministic tools in WSN deployment can aid in providing optimal layouts in terms of coverage, capacity and energy efficiency of the network.
    Electronic ISSN: 1424-8220
    Topics: Chemistry and Pharmacology , Electrical Engineering, Measurement and Control Technology
    Published by MDPI Publishing
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 2
    Publication Date: 2016-06-04
    Description: The aim of the study was deepening the knowledge of livestock innovations knowledge on small-scale farms in developing countries. First, we developed a methodology focused on identifying potential appropriate livestock innovations for smallholders and grouped them in innovation areas, defined as a set of well-organized practices with a business purpose. Finally, a process management program (PMP) was evaluated according to the livestock innovation level and viability of the small-scale farms. Logistic regression was used to evaluate the impact of PMP on the economic viability of the farm. Information from 1650 small-scale livestock farms in Mexico was collected and the innovations were grouped in five innovation areas: A1. Management, A2. Feeding, A3. Genetic, A4. Reproduction and A5. Animal Health. The resulting innovation level in the system was low at 45.7% and heterogeneous among areas. This study shows the usefulness of the methodology described and confirms that implementing a PMP allows improving the viability an additional 21%, due to a better integration of processes, resulting in more efficient management.
    Electronic ISSN: 1999-5903
    Topics: Computer Science
    Published by MDPI Publishing
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 3
    Publication Date: 2016-05-12
    Description: The deployment of the nodes in a Wireless Sensor and Actuator Network (WSAN) is typically restricted by the sensing and acting coverage. This implies that the locations of the nodes may be, and usually are, not optimal from the point of view of the radio communication. Additionally, when the transmission power is tuned for those locations, there are other unpredictable factors that can cause connectivity failures, like interferences, signal fading due to passing objects and, of course, radio irregularities. A control-based self-adaptive system is a typical solution to improve the energy consumption while keeping good connectivity. In this paper, we explore how the communication range for each node evolves along the iterations of an energy saving self-adaptive transmission power controller when using different parameter sets in an outdoor scenario, providing a WSAN that automatically adapts to surrounding changes keeping good connectivity. The results obtained in this paper show how the parameters with the best performance keep a k-connected network, where k is in the range of the desired node degree plus or minus a specified tolerance value.
    Electronic ISSN: 1424-8220
    Topics: Chemistry and Pharmacology , Electrical Engineering, Measurement and Control Technology
    Published by MDPI Publishing
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 4
    Publication Date: 2016-05-28
    Description: Most distributed-generation facilities are performed on pre-built distribution grids. The design conditions of these existing grids may limit the ability of new users to get a connection due to technical and/or cost constraints. This work proposes a simple solution, adjusted to the relevant regulations and embodied in a radial distribution grid of Spanish low voltage, to improve the interconnection of distributed generation, usually grid connected photovoltaic systems. The proposed solution, based on increasing the section of the neutral line, achieves a capacity of increasing the length of the supply grid by more than 20%.
    Electronic ISSN: 1996-1073
    Topics: Energy, Environment Protection, Nuclear Power Engineering
    Published by MDPI Publishing
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 5
    Publication Date: 2015-01-30
    Description: Street lighting has a big impact on the energy consumption of Spanish municipalities. To decrease this consumption, the Spanish government has developed two different regulations to improve energy savings and efficiency, and consequently, reduce greenhouse-effect gas emissions. However, after these efforts, they have not obtained the expected results. To improve the effectiveness of these regulations and therefore to optimize energy consumption, a study has been done to analyze the different devices which influence energy consumption with the intention of better understanding their behavior and performance. The devices analyzed were lamps, ballasts, street lamp globes, control systems and dimmable lighting systems. To improve their performance, they have been analyzed from three points of view: changes in technology, use patterns and standards. Thanks to this study, some aspects have been found that could be taken into account if we really wanted to use energy efficiently.
    Electronic ISSN: 1996-1073
    Topics: Energy, Environment Protection, Nuclear Power Engineering
    Published by MDPI Publishing
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 6
    Publication Date: 2015-10-28
    Description: Most experimental fields of science and engineering require the use of data acquisition systems (DAQ), devices in charge of sampling and converting electrical signals into digital data and, typically, performing all of the required signal preconditioning. Since commercial DAQ systems are normally focused on specific types of sensors and actuators, systems engineers may need to employ mutually-incompatible hardware from different manufacturers in applications demanding heterogeneous inputs and outputs, such as small-signal analog inputs, differential quadrature rotatory encoders or variable current outputs. A common undesirable side effect of heterogeneous DAQ hardware is the lack of an accurate synchronization between samples captured by each device. To solve such a problem with low-cost hardware, we present a novel modular DAQ architecture comprising a base board and a set of interchangeable modules. Our main design goal is the ability to sample all sources at predictable, fixed sampling frequencies, with a reduced synchronization mismatch (〈1 µs) between heterogeneous signal sources. We present experiments in the field of mechanical engineering, illustrating vibration spectrum analyses from piezoelectric accelerometers and, as a novelty in these kinds of experiments, the spectrum of quadrature encoder signals. Part of the design and software will be publicly released online.
    Electronic ISSN: 1424-8220
    Topics: Chemistry and Pharmacology , Electrical Engineering, Measurement and Control Technology
    Published by MDPI Publishing
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 7
    Publication Date: 2014-01-22
    Description: The objective of this paper is to describe a developed model and its corresponding application, known as System to Evaluate the Water Consumption at Home (SEWAT). The aim is to create a new model to evaluate the efficiency of water consumption. Thanks to the input of the water bills by users, the model allows them to check if water consumption is efficient, in order to give them an opportunity to evaluate their water usage. To succeed in it, several researches were tracked in order to establish consumer trends and to identify the most efficient value for this magnitude. Furthermore, a survey was conducted to obtain updated values to validate information from previous studies. However, the main aim of this model is to use the resources efficiently, so it has to be useful accordingly. Therefore, after the evaluation, the application has a section with recommendations for the users to reduce their water consumption through a range of different indications. This section is divided into four: bathroom, kitchen, new appliance and reusing water. Each section shows the expected benefits if the users follow the recommended options. The main result is a unique application in Spain, which includes a system of evaluation, comparison and a section of recommendations for the users. Eventually, the model will have a promising outcome, because it surely will change the awareness of citizens about this subject.
    Electronic ISSN: 2073-4441
    Topics: Energy, Environment Protection, Nuclear Power Engineering
    Published by MDPI Publishing
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 8
    Publication Date: 2014-10-25
    Description: Energy consumption rose about 28% over the 2001 to 2011 period in the Spanish residential sector. In this environment, domestic hot water (DHW) represents the second highest energy demand. There are several methodologies to estimate DHW consumption, but each methodology uses different inputs and some of them are based on obsolete data. DHW energy consumption estimation is a key tool to plan modifications that could enhance this consumption and we decided to update the methodologies. We studied DHW consumption with data from 10 apartments in the same building during 18 months. As a result of the study, we updated one chosen methodology, adapting it to the current situation. One of the challenges to improve efficiency of DHW use is that most of people are not aware of how it is consumed in their homes. To help this information to reach consumers, we developed a website to allow users to estimate the final electrical energy needed for DHW. The site uses three estimation methodologies and chooses the best fit based on information given by the users. Finally, the application provides users with recommendations and tips to reduce their DHW consumption while still maintaining the desired comfort level.
    Electronic ISSN: 1996-1073
    Topics: Energy, Environment Protection, Nuclear Power Engineering
    Published by MDPI Publishing
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 9
    Publication Date: 2014-12-02
    Description: Wireless Sensor Networks (WSNs) are generally used to collect information from the environment. The gathered data are delivered mainly to sinks or gateways that become the endpoints where applications can retrieve and process such data. However, applications would also expect from a WSN an event-driven operational model, so that they can be notified whenever occur some specific environmental changes instead of continuously analyzing the data provided periodically. In either operational model, WSNs represent a collection of interconnected objects, as outlined by the Internet of Things. Additionally, in order to fulfill the Internet of Things principles, Wireless Sensor Networks must have a virtual representation that allows indirect access to their resources, a model that should also include the virtualization of event sources in a WSN. Thus, in this paper a model for a virtual representation of event sources in a WSN is proposed. They are modeled as internet resources that are accessible by any internet application, following an Internet of Things approach. The model has been tested in a real implementation where a WSN has been deployed in an open neighborhood environment. Different event sources have been identified in the proposed scenario, and they have been represented following the proposed model.
    Electronic ISSN: 1424-8220
    Topics: Chemistry and Pharmacology , Electrical Engineering, Measurement and Control Technology
    Published by MDPI Publishing
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 10
    Publication Date: 2018-08-11
    Description: Sustainability, Vol. 10, Pages 2851: An Analysis of the Factors behind the Citizen’s Attitude of Rejection towards Tourism in a Context of Overtourism and Economic Dependence on This Activity Sustainability doi: 10.3390/su10082851 Authors: José María Martín Martín Jose Manuel Guaita Martínez José Antonio Salinas Fernández New tourism trends, such as vacation rentals websites and low-cost tourism, have generated a new environment of interactions between tourism and the citizens. To this, we must add the fortuitous increase in demand in some touristic destinations. This has derived in situations of rejection in traditionally tourism-dependent environments. In this study, which is focused on the city of Barcelona, we use work-field data to analyze the elements that lie behind the popular aversion to tourism. Assuming a non-forced analysis that takes the Social Exchange Theory as a framework, we have determined that the negative economic effects derived from the increase in the number of accommodations destined for vacation rentals and in the demand lie behind this rejection. The main impacts that are perceived directly from these factors are: the increase in residential rentals prices and a shift from a traditional market to one oriented to the tourist with higher prices. It has also been determined that the most vulnerable population groups are those who manifest a stronger rejection, tenants of apartments in city centers, and citizens with a low/medium income, who perceive rises in the prices and a change in the market focus to a larger extent.
    Electronic ISSN: 2071-1050
    Topics: Energy, Environment Protection, Nuclear Power Engineering
    Published by MDPI Publishing
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...