Miracle-dz/UniFAR-FTUs huggingface dataset:
Millimeter-Wave Low-Profile Continuous Transverse Stub Arrays With Novel Linear Source Generators

This paper presents a new type of continuous transverse stub (CTS) antenna array with a novel linear source generator (LSG). The conventional multilayer parallel-plate waveguide (PPW) feed and pillbox structure are eliminated and replaced with a more compact partially corporate feed network. This helps to achieve a lower profile (or reduction of antenna layers) and high performance of broadband and high efficiency. For validation, two prototypes are demonstrated—one based on hollow waveguides operating at 34–41 GHz (Array-I) and the other based on substrate integrated waveguides operating at 24.5–29.5 GHz (Array-II). Both arrays contain eight radiation slots, fed from a single-layer PPW junction. The required quasi-transverse electromagnetic wave excitations are achieved by using the novel LSG of a jagged cavity structure. The detailed design methodology and analyses are provided in this paper. Measurements show that antenna efficiencies of over 83% and 82% with the peak gains of better than 27.6 and 20.6 dBi are achieved for Array-I and Array-II, respectively. These low-profile CTS designs are well suited for current and emerging millimeter-wave applications such as 5G and point-to-point communications.
A 1-MHz-Bandwidth Gm-C-Based Quadrature Bandpass Sigma-Delta Modulator Achieving −153.7-dBFS/Hz NSD With Background Calibration

This paper presents a fifth-order continuous-time Gm-C-based quadrature bandpass sigma-delta (<inline-formula> <tex-math notation="LaTeX">$\Delta \Sigma$ </tex-math></inline-formula>) modulator for Internet-of-Things applications. In the presented <inline-formula> <tex-math notation="LaTeX">$\Delta \Sigma $ </tex-math></inline-formula> modulator, a reconfigurable full-scale input amplitude assists the <inline-formula> <tex-math notation="LaTeX">$\Delta \Sigma $ </tex-math></inline-formula> modulator, achieving a wide dynamic range (DR) and a low-noise floor. A following system-level supply voltage and temperature background tracking technique stabilizes the frequency response of the Gm-C-based quadrature bandpass <inline-formula> <tex-math notation="LaTeX">$\Delta \Sigma $ </tex-math></inline-formula> modulator. Furthermore, the 1.5-bit feedback current DAC employs a PN-based semi-self-swapping logic to relax the matching requirement. The prototype <inline-formula> <tex-math notation="LaTeX">$\Delta \Sigma $ </tex-math></inline-formula> modulator was fabricated in a 180-nm CMOS process with an active area of 0.28 mm<sup>2</sup>. The <inline-formula> <tex-math notation="LaTeX">$\Delta \Sigma $ </tex-math></inline-formula> modulator achieves a total DR of 93.7 dB with the reconfigurable full-scale input amplitude, resulting in a noise spectral density of −153.7 dBFS/Hz with a bandwidth of 1 MHz. The presented <inline-formula> <tex-math notation="LaTeX">$\Delta \Sigma $ </tex-math></inline-formula> modulator consumes 2.0 mW with a power supply of 1.8 V and a sampling frequency of 32 MHz.
Robotic Arm Based Automatic Ultrasound Scanning for Three-Dimensional Imaging

This paper presents a human skin inspired automatic robotic ultrasound (US) system for three-dimensional (3-D) imaging. A depth camera was adopted to capture the point cloud of the skin surface. According to the 3-D contour of the skin surface, the scan range and scan path for the US probe could be automatically determined. Then, we used a normal-vector-based method to determine the pose of the robotic arm corresponding to each scan point in the scan path. In addition, two force sensors could feedback the contact force between the scanned tissue and the emission plane of the probe for fine-tuning the pose of the robotic arm. After the scanning, the system could realize 3-D US reconstruction. Experimental results validate the feasibility of the proposed system. It is expected that the proposed system will be useful in clinical practices.
Towards Characterizing Domain Experts as a User Group

Visualization is an inherently interdisciplinary research area: visualization researchers are always visualizing other people’s data. While recent trends in the field has turned toward a more inclusive audience, particularly within the topic of “visualization for the masses”, the traditional user group for our tools have been the domain expert: people who are experts in a specific professional domain where they want to apply visualization and analytics, but who often lack high literacy, training, and motivation in visualization and visual analytics. Such domain experts want to opportunistically reap the benefits of visualization, but have no patience for long training, poor interaction or visual design, or complex displays. While domain experts are a familiar user group, surprisingly little effort has been devoted towards characterizing them for both design and evaluation purposes. To help the visualization community better understand this specific group, in this paper, we describe the characteristics of domain experts, discuss existing examples designed for them, and propose possible guidelines to facilitate the design process. We believe this discussion will help visualization researchers better understand this group and uncover more research opportunities.
A Framework for Developing VPP Conceptual Models: From Multiple Dimensions and Stakeholders, Towards a Unified Perspective

Virtual Power Plants (VPP) are one of the most important concepts today for offering flexible control and management of distributed generation and load resources for supporting grid operation. By virtue of aggregating flexible negative and positive generation resources, or 'flex', into a single portfolio and offering it to entities who are customers of 'flex', the VPP needs to offer different value propositions to different customers. For utilities, cities, residential communities, industry parks, or clusters of small & medium enterprises, a VPP not only offers grid stability, new revenue sources, and a more sustainable and greener future, it also raises the question: How can different entities come together to foster the VPP concept and realize a common value creation network. This paper proposes a structured and methodical framework for evaluating the frame conditions, designing multiple VPP conceptual models for different value chain segments, and finally, creating integrated VPP conceptual models that can be used as starting points for detailed financial and operational planning.
A New Methodology Of Auto-Adaptive PN Code Acquisition For Spread Spectrum Communications Environment

In this paper, we propose a robust and novel approach for auto-adaptive pseudo noise PN code serial acquisition based on Order Statistic Constant False Alarm Rate (OS-CFAR) for mobile communication systems over multipath environment. The new approach is called Automatic Selection Order Statistic (ASOS)-CFAR. It uses all available information based on the ML estimation to identify automatically the ranked cell from ranked data cells that indicates the discrimination between homogeneous and non-homogeneous environments, in order to use it to compute the adaptive threshold. Monte- Carlo simulations in a multipath environment indicate that the proposed approach has a high ability to sense the mobile communications environments, thus getting to produce a correct detection decision, without requiring any prior knowledge regarding the number of multipath signals.
Personality and Preference Modeling for Adaptive Storytelling

In almost all forms of storytelling, the background and the current state of mind of the audience members predispose them to experience a given story from a unique personal perspective. However, traditional story writers usually construct their narratives based on an average understanding of the preferences of their audience, which does not guarantee satisfying narrative experiences for its individual members. When a narrative is aimed at providing pleasurable entertainment, having some information about the preferences of the current user for the narrative’s content is vital to create satisfying experiences. This paper explores personality modeling and proposes a novel approach to generate individualized interactive narratives based on the preferences of users, which are modeled in terms of the Big Five factors. The paper presents the proposed method and evaluates its precision and real-time performance.
Improving the Third Quadrant Operation of Superjunction MOSFETs by Using the Cascode Configuration

In this paper, the third quadrant behavior of a high-voltage superjunction <sc>mosfet</sc> (SJ-FET) in cascode configuration (CC) with a low-voltage silicon <sc>mosfet</sc> is deeply studied by means of an analytical model and experimental data. The third quadrant dynamic behavior of the SJ-CCs is compared to the standalone counterparts by evaluating their reverse recovery time (t<sub>RR</sub>), reverse recovery peak current (I<sub>RRM</sub>), and reverse recovery charge (Q<sub>RR</sub>). An analytical model and experimental results show that the SJ-CC avoids or mitigates the activation of the SJ-FET body diode during the third quadrant operation. As a consequence, the SJ-CC strongly improves the widely used figure-of-merit R<sub>ON</sub>·Q<sub>RR</sub>, which considers the <sc>on</sc>-state resistance of the transistors (R<sub>ON</sub>). In addition, the results obtained using an SJ-CC are similar or better than those achieved by SJ-FETs with enhanced reverse recovery (i.e., irradiated SJ-FETs). This paper also includes a comparison with commercial wide bandgap switches, concluding that the R<sub>ON</sub>·Q<sub>RR</sub> value provided by the SJ-CC is around eight times higher than that provided by a commercial GaN cascode.
A Parallel-Output CLTCL Multi-Resonant Soft-Switching DC-DC Converter

In this paper, a novel CLTCL multi-resonant soft-switching DC-DC converter is proposed. It employs the dual transformers architecture, whose secondary sides are connected in parallel. The resonant tank contains multiple resonant components of capacitors and inductors. Through the appropriate parameter design, the converter can transmit the 1st and the 3rd harmonic active power simultaneously. Consequently, the utilization rate of the resonant current and high efficient conversion are both guaranteed. Widely adjustable DC voltage gain range is also achieved within a narrow frequency range. Besides, all the power switches obtain the turn-on zero-voltage-switching (ZVS), while the diodes attain the turn-on and turn-off zero-current-switching (ZCS) or quasi ZCS (Q-ZCS). To verify the feasibility of the converter, a 500W prototype is built and tested. The proposed converter is able to maintain relatively high efficiency (around 95%) among a wide load range. The highest efficiency reaches 95.4% at 300W.
A Dual-Band Shared-Aperture Antenna With Large Frequency Ratio, High Aperture Reuse Efficiency, and High Channel Isolation

The operating frequency of future communication systems will cover unlicensed millimeter-wave bands as well as existing microwave bands. Large frequency ratio antennas that can be applied to both frequency bands simultaneously and maintain the high isolation between the two channels are difficult to design. This paper presents a new design of dual-band shared-aperture antenna based on the concept of structure reuse. The antenna consists of a patch antenna working at 3.5 GHz and a $12 \times 12$ substrate integrated waveguide (SIW) slot array antenna working at 60 GHz. The frequency ratio of this shared-aperture antenna is 17. In this design, the overall structure of the SIW slot array antenna is employed as the radiator of the patch antenna. With this new scheme, the high aperture reuse efficiency can be achieved. Meanwhile, the millimeter-wave antenna based on the SIW technology has the high-pass nature to reject the lower frequency signal. A compact microstrip resonant cell that acts as a low-pass filter is connected in series on the feedline of the microwave antenna to suppress the upper frequency signal. Thus, the channel isolation between the patch and the SIW slot array antennas can be more than 130 dB at 3.5 GHz and 65 dB at 60 GHz.
An Adaptable Interface Circuit With Multistage Energy Extraction for Low-Power Piezoelectric Energy Harvesting MEMS

This paper presents a self-powered interface circuit to extract energy from ambient vibrations for powering up microelectronic devices. The circuit interfaces a piezoelectric energy harvesting micro electro-mechanical systems (MEMS) device to scavenge acoustic energy. Synchronous electric charge extraction (SECE) technique is deployed through the implementation of a novel multistage energy extraction (MSEE) circuit in 180 nm HV CMOS technology to harvest and store energy. The circuit is optimized to operate with minimum power losses when input power is limited, and adapts well to operating conditions with higher input power. The highly accurate peak detector was validated for a wide piezoelectric frequency range from 20 Hz to 4 kHz. A charging efficiency of about 84% has been achieved for 4.75 V open-circuit piezoelectric voltage excited at 390 Hz input vibration under nominal input power range of 30–80 μW. Power optimizations enable the circuit to maintain a conversion efficiency of 47% at input power level as low as 3.12 μW. MSEE provides up to 15% efficiency improvement compared to traditional SECE, and maintains power efficiency as high as possible for a wide input power range.
Jamming Simulation of Synthetic Aperture Radar Imaging

Study on the jamming techniques against synthetic aperture radar is one of the important topics in the field of electronic warfare. This paper introduces the jamming principle of synthetic aperture radar imaging, including barrage jamming and deceptive jamming, and proposes an adjustable triangular wave pre-aggravate frequency modulation jamming method for barrage jamming. A basic deceptive algorithm which can generate false targets at specific locations is simulated. Simulation results show that this algorithm can effectively protect the region.
Comparative Assessment of Non-Isolated DC-DC Converters Combined with Passive Ripple Cancelling Circuit

Extreme frequency utilizations instinctively evolve current ripples in switching power converters, whichever may induce a crucial impression on the output power. Aforementioned ripple current conceives filtering complications, control concerns, output voltage disorder as well as more obstacles. In this study a dynamic passive ripple cancelling circuit (PRCC) is observed, which is used to erase current ripples of the converters. BOOST, CUK, SEPIC and a modified version of SEPIC converters are adopted to explore the efficacy of this ripple eliminating technique. It is detected that by integrating PRCC into the conventional converters, appearing peak to peak input current ripple is declined and ripple eliminating proportion is beyond 97% for all the studied circumstances. The survey is performed depending on steady state evaluation and simulation. MATLAB/SIMULINK mechanism is used to achieve simulated outcomes. However, comparative assessment is executed to determine foremost performing DC-DC converter incorporated with PRCC.
Web Services in the Internet of Things and Smart Cities: A Case Study on Classification Techniques

Consumer electronics (CE) are considered an indispensable and inseparable part of the Internet of Things (IoT). The four-layer architecture of the IoT includes CE devices as its core layer. Furthermore, the IoT provides all necessary infrastructures for realization of the smart city concept. Various services offered in a smart city are implemented with the help of web service technology, and there are multiple web services offering identical functionality. Selecting the most appropriate web service to obtain the desired functionality is a fundamental problem in smart city development. In this article, a tripplanning case study is discussed to highlight the role of web services in a smart city, and six learning models for web service classification are described.
Performance Comparison of Multicast Protocols in Mobile Social Networks

Connecting mobile computing devices, such as smartphones and tablets, anytime and anywhere has been the target of mobile networks in recent decades. Nowadays, this concept is extended to connecting selected people, which requires knowing the social profile of the device users, and therefore created the Mobile Social Network (MSN). Multicast routing in MSNs is concerned with finding and selecting people to deliver a message. Traditional multicast routing protocols do not consider the users’ profile. Recently, some social multicast protocols have emerged. These protocols consider the social behavior and relationships of the users to decide which nodes can act as relays and which ones can be considered destinations.The aim of this paper is to experimentally compare and analyze the performance of three known protocols in MSNs. The performance measures used are: delivery ratio, relay count, overhead ratio, hop count and dropped packets. The experiments are run with different network sizes, variable buffer capacities and packets Time-To-Live (TTL). The paper is concluded with a summarized analysis of the compared protocols.
Design of Green Indoor IoT Networking Through Optical Wireless Communication Using Passive Optical Reflectors

This paper presents the proof of concept for energy-saving passive communication for the networking of smart indoor Internet of Things (IoT). The Optical Wireless Communication (OWC) enables the smart devices to communicate through flicker-free infrared (IR) spectrum without neglecting the human safety measures. With low power, high data rate communications on orders of 10 Gbps are achieved from the smart devices without having the power-consuming active sources in the user devices. The replacement of active sources with the passive optical reflectors can make the technology greener. Henceforth, it enables the high-capacity and low-cost passive communication in indoor IoT. Additionally, the different linewidth sources are analyzed to find out the optimum source for the low power communication. The analysis shows that the sources with the linewidth of 10 MHz, 10 GHz and 1 PHz maintained the quality of transmission at the low power levels of −50 dBm and −60 dBm. The best result achieved with this design is that the 1 PHz linewidth sources offer the errorless communication having the Quality factor of 48 at the power of −60 dBm. The other advantages of having the wider sources are also analyzed and discussed.
Impedance-Based Modelling Method for Length-Scalable Long Transmission Cable for Stability Analysis of Grid-Connected Inverter

This paper presents an impedance-based modelling method for length-scalable long transmission cable (LTC), which is able to assess influence of LTC on stability of grid-connected inverter (GCI). Electrical parameters of power cable in per-unit-length (p.u.l.) are first extracted from the measured terminal short-circuited and open-circuited admittances. Then, the terminal admittance of power cable in different length can be derived on the basis of the obtained p.u. l. parameters. Finally, a decoupled two-port circuit model is established for the LTC using the derived terminal admittance. Simulation results are given to validate effectiveness of the proposed impedance-based modelling method for LTC. The proposed impedance-based modelling method is able to avoid repetitive terminal impedance measurement. Also, the proposed model is able to support impedance-based stability criterion for GCI with length-scalable LTC.
A Variational Approach to Minimum-Jerk Trajectories for Psychological Safety in Collaborative Assembly Stations

Collaborative robotics is one of the main drivers of the fourth industrial revolution, where robots and humans cooperate in a shared workspace. Such robots are distinguished from the traditional robots by several features that, if tuned correctly, ensure safe physical interaction. However, interaction with robots also represents a potential source of psychological stress. Indeed, it has been proven that working and sharing the workspace with robots can psychologically stress the operator. This drawback—in addition to the reduced speed operation imposed by safety standards—represents a constraint difficult to bear for small and medium-sized enterprises. In this letter, we propose a novel trajectory-planning methodology for collaborative robots able to ensure both psychological and physical safety. We rely on the available literature and the calculus of variations to identify a family of psychologically acceptable minimum-jerk trajectories. From the identified family, we compute the fastest trajectory that limits the physical danger represented by the robot. A numerical implementation of the method is discussed, and experimental results prove the effectiveness of the idea.
A Learning-Based Positive Feedback Approach in Salient Object Detection

Motivated by human visual system, a HELM-based positive feedback approach is proposed which intensifies salient objects and promotes the saturation of human perception on a fixation area. Randomly-weighted deep neural networks are applied online to our method and lead to stable performance. Our algorithm is data-driven totally and does not need any prior knowledge compared to the existing approaches. Experimental results based on the standard image datasets show that our approach is an effective one to enhance the performance compared to the existing algorithms.
A Low Power Receiver Front-End Design With Tunable Notch Filter for TX Leakage and Blocker Suppression

An active transmitter self-leakage suppressor for frequency-division duplex transceivers is presented. A wideband active notch filter is implemented at the mixer IF ports to suppress out the transmitter leakage. Since the active notch filter is operating at IF frequencies, its noise, power, and area consumption penalty for the overall transceiver is negligible, and it does not require any complicated amplitude and phase calibration circuitry that is necessary for the cancelers which operate at RF frequencies. Due to the transfer function seen by the active notch-filter, its noise and distortion contribution is shaped and reduced further. The proposed design is implemented in a 65 nm standard CMOS process for an LTE receiver and provides minimum of 5 dB attenuation at duplex distance for E-UTRA band 20. For the same frequency band, it enhances the IIP2 and IIP3 of the receiver with a minimum of 12 and 6 dB, respectively. The active filter consumes only 1.1 mA/channel from a 2.5 V supply and occupies 0.078 mm2/channel. Its noise contribution is within the NF measurement error, thus negligible. The design is intended and tested for transmitter self-interference and wideband ACS blockers.
All-Metal Endfire Antenna With High Gain and Stable Radiation Pattern for the Platform-Embedded Application

This paper presents a novel high-gain endfire slot antenna array fed by air-substrate microstrip line. It has a simple and compact structure consisting of a copper strip and two copper sheets. Designed based on the slot antenna array, the antenna could be embedded into a large metallic platform. The surface wave above the antenna radiates the energy to free space. Fed by the air-substrate microstrip line, the antenna works on the TEM mode. Therefore, the antenna obtains a suitable phase constant to realize stable endfire radiation pattern and could be designed by a long structure to realize high endfire gain. Because all of the antennas are designed by metal, it has the characteristics of high strength, easy fabrication, and low cost. With the radiating aperture of 3.5 wavelength, the antenna achieves a measured endfire gain of 11.81 dBi. The measured 1 and 3 dB gain bandwidths reach 4.5% and 8.4%, respectively. Good matching and stable endfire radiation pattern are obtained over the entire operating band from 3.75 to 4.15 GHz.