Study of GeSn (0.524 eV) Single-Junction Thermophotovoltaic Cells Based on Device Transport Model

Based on the transport equation of the semiconductor device model for 0.524 eV GeSn alloy and the experimental parameters of the material, thermal-electricity conversion performance governed by GeSn diode has been systematically studied in its normal and inverted structure. For the normal p+/n (n+/p) structure, it is demonstrated here that an optimal base doping N d(a) = 3 (7)×1018 cm-3 is observed, and the superior p+/n structure can reach the higher performance. To reduce material consumption, an economical active layer can be comprised of 100-300 nm emitter and 3-6 μm base to attain comparable performance as that for the optimal configuration. The results can offer many useful guidelines for the fabrication of economical GeSn thermophotovoltaic devices.

Automating IoT Data Ingestion Enabling Visual Representation

The Internet of things has produced several heterogeneous devices and data models for sensors/actuators, physical and virtual. Corresponding data must be aggregated and their models have to be put in relationships with the general knowledge to make them immediately usable by visual analytics tools, APIs, and other devices. In this paper, models and tools for data ingestion and regularization are presented to simplify and enable the automated visual representation of corresponding data. The addressed problems are related to the (i) regularization of the high heterogeneity of data that are available in the IoT devices (physical or virtual) and KPIs (key performance indicators), thus allowing such data in elements of hypercubes to be reported, and (ii) the possibility of providing final users with an index on views and data structures that can be directly exploited by graphical widgets of visual analytics tools, according to different operators. The solution analyzes the loaded data to extract and generate the IoT device model, as well as to create the instances of the device and generate eventual time series. The whole process allows data for visual analytics and dashboarding to be prepared in a few clicks. The proposed IoT device model is compliant with FIWARE NGSI and is supported by a formal definition of data characterization in terms of value type, value unit, and data type. The resulting data model has been enforced into the Snap4City dashboard wizard and tool, which is a GDPR-compliant multitenant architecture. The solution has been developed and validated by considering six different pilots in Europe for collecting big data to monitor and reason people flows and tourism with the aim of improving quality of service; it has been developed in the context of the HERIT-DATA Interreg project and on top of Snap4City infrastructure and tools. The model turned out to be capable of meeting all the requirements of HERIT-DATA, while some of the visual representation tools still need to be updated and furtherly developed to add a few features.

A High-Gain CNTFET-Based LNA Developed Using a Compact Design-Oriented Device Model

Recently, carbon nanotube field-effect transistors (CNTFETs) have attracted wide attention as promising candidates for components in the next generation of electronic devices. In particular CNTFET-based RF devices and circuits show superior performance to those built with silicon FETs since they are able to obtain higher power-gain and cut-off frequency at lower power dissipation. The aim of this paper is to present a compact, design-oriented model of CNTFETs that is able to ease the development of a complete amplifier. As a case study, the detailed design of a high-gain CNTFET-based broadband inductorless LNA is presented.

Object Tracking Devices using Android Application

Millions of smart devices are mushrooming in this digital environment to meet the difficulties posed by innovations and technological advancements in ubiquitous computing. All of these smart gadgets are exposed to everyday objects that are linked to the Internet. Web of Things is a term that defines how various objects are connected to the Internet and communicate with one another using web standards. The emergence of omnipresent systems makes human beings' jobs easier. People were able to live lavish existence in the most comfortable environment because of these inventions. Finally, everyone began to keep their valuables in accordance with their activities inside the house or at work, and they began to hide them under misplaced or lost belongings. Every house has a history of searching for keys, wallets, pen drives, and hand purses, which may be a time-consuming task, especially during times of high demand. A device model is presented to reduce this effort and save time by allowing lost objects to be tracked and traced out. The suggested work serves as a foundational notion for describing how to track items in a practical manner. This is a basic device model that describes how to track an object using an Android mobile device and a Wi-Fi connection with the Blynk app and GPS controllers.

Adaptive filter and pulse-shaping for interference cancellation of differential quadrature phase-shift keying modulation

Differential quadrature phase-shift keying (DQPSK) modulation methods and variations are commonly used in wireless communication, including high-speed optical fiber, Bluetooth, and satellite communication. DQPSK cannot be isolated from possible interference with its present application. The interference cancellation process has been observed and analyzed using a device model built in this study. The core components of the supporting block for this device model have raised cosine filters for pulse shaping and adaptive filters. The presence of these core components has resulted in a dramatic improvement in device efficiency, according to robust Simulink data. The best bit error rate (BER) of 5.7e-03 provides evidence of this.

A Novel Software Architecture Solution with a Focus on Long-Term IoT Device Security Support

This paper presents a solution for upgrading a previous device model to an Industry 4.0 smart device, with the goal of maintaining high compatibility. A novel IoT architecture is presented that satisfies the characteristics of a smart device. We analysed existing IoT architectures and proposed a new architecture to achieve long-term security and usability. To ensure long-term security, we eliminated the possibility of device configuration outside the immediate vicinity of the device with a dedicated protocol. The security concepts of the existing architectures were also analysed and further modified. To improve compatibility with previous device models, we propose a new method to collect data from sensors by introducing a multithreaded microcontroller. We propose additional software components to ensure factory programming, maintenance, and cloud Big Data analysis. Based on our experiments, we adapted the algorithm to increase the accuracy of the temperature and flow sensors by using a temperature calibration device and known flow cycles. Measurement results are presented to confirm the successful upgrade. We designed a hardware architecture to ensure compatibility with previous and future device models. Issues with previous sensors encountered during the upgrade were discussed and resolved. A novel software architecture based on security for long-term IoT devices is proposed.

The Evaluation of the Lighting at the Entrance of Very Long Tunnels

Background: One of the major topics related to the very long tunnels is dark hole effect. This is a common phenomenon caused by the sunlight reflected from the surroundings of the tunnel to the eyes of drivers and the lack of sufficient light at the tunnels' entrance, which decreases the contrast of barriers inside the tunnel and also makes it difficult to see potential obstacles at the entrance. The result is an increased risk of traffic accidents in these tunnels. Therefore, the aim of this research is to subjectively assessment the safe rate of lighting in one of the very long tunnels located in the province of Ilam. Methods: To subject evaluation the safe rate of lighting at the tunnel entrances, two parameters of the average luminance of tunnel entrance and equivalent luminance are required. In this study, Luminancemeter device model S3 was used to measure the average luminance of tunnel entrance. Then, to calculate the equivalent luminance, a YASHICA108 camera with a 35 mm lens was photographed at a distance between the tunnel entrance and a safe stopping point, and then the Holliday polar diagram was used to calculate equivalent luminance (accordance with the standard CIE88-2004). Results: In this study, the average luminance at tunnel's entrance was equal to 17 , the luminance was equal to 127.5 Using the ADRENAL equation, the quality of lightening at the tunnel entrance was less than 1. Conclusion: Comparison of the results obtained from the healthy and safety rate of lighting levels at the tunnel's entrance with the De Boer mental scale indicated that a dark hole effect occurs at the entrance of the tunnel under investigation and the light sources installed at the entrance of this tunnel did not have the sufficient ability to inhibit the dark hole effect.