Search results for "POWER"

A Self-Powered Long-range Wireless IoT Device based on LoRaWAN

2020

In this article, we propose a self-powered long-range wireless Internet-of-Things (IoT) device based on Long Range Wide Area Network (LoRaWAN) with various sensing capabilities. The nodes are designed based on ambient energy harvesting in such a way that these are self-sustainable throughout the components’ lifespan. Also, these nodes can be deployed on a large scale and are maintenance-free. In addition, these nodes can be deployed in remote places where the accessibility is limited, and maintenance is difficult. The wireless sensor nodes can be deployed both in indoor and outdoor environments with sufficient light levels for the solar panel, such as indoor lights in the indoor environment…

Development of a High Granularity Photovoltaic Model That Considers Complex Nonuniform Shadow Conditions and Different Cell Temperatures

2012

In this paper is the development of a high granularity photovoltaic model that considers complex nonuniform shadow conditions and different cell temperatures. The model integrates the nonuniform shading characteristics such as different areas for each cell, different direct and indirect solar irradiations for each cell, and different temperatures. The area of the shadow on the PV module is found using image processing. The bond graph formalism facilitates the representation of the energy exchange between the different parts of the PV module. This complexity justifies the effort to develop a high-granularity tool. The proposed model is validated through experimental tests under shading condi…

Experimental Characterization of Mobile Fading Channels Aiming the Design of Non-Wearable Fall Detection Radio Systems at 5.9 GHz

2016

One of the major concerns for the independent living of elderlies is a fall incident. To decrease human interaction errors and user privacy concerns of existing fall detection systems, a new generation of fall detection systems is emerging. The new trend is to design non-wearable devices that can monitor the physical activities of the home user using radio waves reflected off the body. This paper reports an in-home radio measurement campaign at 5.9 GHz, which has been conducted to study the impacts of different physical activities of the user, including fall incidents, on the channel transfer function (CTF) and the power delay profile (PDP) of indoor mobile radio channels. The home is equip…

A wireless battery charger architecture for consumer electronics

2012

In this paper, an innovative design of a wireless battery charger for portable electronic devices is proposed. The wireless power transfer is implemented through the magnetic coupling between a power transmitter, which is connected to the grid, and a power receiver, which is integrated inside the load device. An innovative receiver architecture which heavily improves the power conversion efficiency is presented. The proposed solution is standard compliant and suitable for IC implementation. A comparison between a conventional and the proposed receiver architectures is carried out by SPICE simulations. As shown by simulation results, a power efficiency increase by 40% is provided by the prop…

Path Dependence of Power Relations, Path-Breaking Change and Technological Adaptation

2011

We study the path dependence of technological systems and power relations inside companies. While the existing literature suggests power relations and technology to be path dependent and influenced by each other, interactions across these evolutionary processes remain poorly understood. We studied the history of four retail firms over 40 years, applying event structure analysis to explicate key dynamics. Companies exhibited two episodes of converging path dependency, where power relations further increased technological inertia. In each case, power initially concentrated outside the central headquarters. Path-breaking change led all firms to centralize power and implement networked IT syste…

Economic Diversification and Empowerment of Local Human Resources: Could Singapore Be a Model for the GCC Countries?

2018

This chapter analyses the similarities and differences between the GCC and Singapore with regard to economic diversification strategies. The key for a successful and, thus, sustainable diversification process for the GCC is to reduce the high dependence of the economic revenues away from the hydrocarbon sector. However, an ongoing concern is the continuing need of high foreign workforce that collides with the demands for greater employment opportunities for national citizens. The challenges of those nationalisation strategies will be examined at the example of the Sultanate of Oman.

A simple operation strategy of battery storage systems under dynamic electricity pricing: An Italian case study for a medium-scale public facility

2014

In the electricity market, wholesale energy prices depend on the balance between energy production and load demand. In the last few years, electricity market has become more and more flexible as many utilities have started to replace the fixed retail prices schemes with prices changing during the day. Dynamic pricing, also known as Real-Time Pricing (RTP), reflects the trend of the wholesale market and allows to reduce the volatility of the wholesale prices, also contributing to a reduction of demand peaks. Electricity customers take advantage of dynamic pricing by shifting their consumption according to the real-time prices or by using Battery Energy Storage Systems (BESS) to shift electri…

Impact of non-programmable renewable sources in Day-Ahead Market in Sicily. Reasons to make more flexible and smarter the national transmission grid.

2014

This article describes technical and market aspects that characterize the Sicilian electrical system, the non-programmable renewable sources impacts on the energy markets (Day-Ahead Market and ancillary services market) and on Sicilian system operation, to evaluate the grid integration of renewable energy sources in a future Sicilian smart grid.

DYNAMIC MODELING TOOLS FOR SOLAR POWERED DESALINATION PROCESSES DURING TRANSIENT OPERATIONS

2007

Maids and housekeepers at luxury hotels: life stories in hotels of Buenos Aires, Argentina

2021

The tourism industry evinces a high turnover of staff which needs further hard training and organisation. Broadly speaking, the service quality seems to be directly proportional to excessive working hours, which are accompanied by less-paid wages and hard working conditions. This paper interrogates furtherly on the (real) motivations of maid and housekeepers who are professionally educated to serve high purchasing power tourists. The research focuses on the needs, socio-economic background of maid and housekeepers as well as the pro and cons of their daily tasks. Based on the life story and story-telling and as the main method of study, we conduct exploratory research -sampled by 8 in-depth…