Miracle-dz/UniFAR-FTUs huggingface dataset:
High-Performance Nonequilibrium InSb PIN Infrared Photodetectors

The cooling requirement is still a great burden of sensitive infrared (IR) detectors. To overcome this challenge, a detailed investigation of InSb P-intrinsic-N diodes was conducted. Its dark current was comprehensively studied for the design and optimization of high-performance nonequilibrium IR detectors. The doping concentration, exclusion junction, and layer geometry were engineered to lower the Auger suppression trigger current density <inline-formula> <tex-math notation="LaTeX">${J}_{\text {onset}}$ </tex-math></inline-formula>, leading to a low dark saturation current <inline-formula> <tex-math notation="LaTeX">${J}_{\text {sat}}$ </tex-math></inline-formula>. The result indicated that the Auger suppression can be triggered at <inline-formula> <tex-math notation="LaTeX">${J}_{\text {onset}}={15}$ </tex-math></inline-formula> A/cm<sup>2</sup> and <inline-formula> <tex-math notation="LaTeX">${V}_{\text {onset}} = {0.8}$ </tex-math></inline-formula> V, while <inline-formula> <tex-math notation="LaTeX">${J}_{\text {sat}}$ </tex-math></inline-formula> can be kept as low as 10 A/cm<sup>2</sup>. The nature of Auger suppression has been studied by calculating the carrier concentration profile in the diode with different bias voltages. It is proven that the exclusion diode has the most significant effect on the Auger suppression. The specific detectivity of optimized nonequilibrium InSb detectors at different temperatures has been compared favorably with the results reported by other groups. Such a nonequilibrium InSb IR detector has a high potential in room temperature and above application.
Technology Roadmap for Time-Division Multiplexed Passive Optical Networks (TDM PONs)

Commercial passive optical networks (PONs) up to 10 Gb/s have traditionally leveraged mature components from transport and metro transport systems. Starting soon with 25G PON, the data center ecosystem will be leveraged. A strategy to accommodate the higher speed of 25 Gb/s at low incremental cost to 10G PON is presented—essentially to adhere to a simple architecture and to avoid the need for expensive optical amplification. The 25G PON wavelength plan and co-existence scenarios with existing PONs are described. The ability of time-division multiplexed (TDM) PONs to address the 5G backhaul, midhaul, and fronthaul transport use case is evaluated. The technology roadmap to a future 50G TDM PON is discussed. Analysis of the major challenge, meeting PON loss budgets at 50 Gb/s with higher launch power, is presented, including the cost dependence of transmitter power. This is followed by a short review of research in the field of coherent detection in PON systems, which will be important for 100G PON.
A Compact Transformer-Combined Polar/Quadrature Reconfigurable Digital Power Amplifier in 28-nm Logic LP CMOS

This paper presents a transformer-combined dual-mode reconfigurable digital Class-D power amplifier (PA) that supports polar and quadrature transmitters (TXs). Transformer-based load modulation is employed to enhance the efficiency in both modes. The PA is implemented in 28-nm logic LP CMOS and occupies only 0.56 mm<sup>2</sup> active area. The polar mode achieves 28.8-dBm peak power with the PAE of 30.8% at peak power and 22.4% at 6-dB backoff. The quadrature mode obtains 26.3-dBm peak power and 22.9% peak PAE. For 20-MHz 64 Quadrature Amplitude Modulation (QAM) WLAN signals, the PA achieves 23.35-dBm <inline-formula> <tex-math notation="LaTeX">$P_{\mathrm {avg}}$ </tex-math></inline-formula>, 23.2% PAE, −25.4-dB error vector magnitude (EVM) in polar mode and 18.50-dBm <inline-formula> <tex-math notation="LaTeX">$P_{\mathrm {avg}}$ </tex-math></inline-formula>, 12.3% PAE, −25.2-dB EVM in quadrature mode.
Non-Smooth Bifurcation Analysis of Multi-Structure Multi-Operating-Mode Power Electronics Systems for Applications With Renewable Energy Sources

The stand-alone hybrid renewable power generation systems for local applications have gained popularity in recent years. However, due to the intermittent nature of the renewable resources, the hybrid renewable power generation systems are often designed to operate with multi-structure and multi-operating-mode. As a result, a non-smooth bifurcation may occur as the system switches its operating mode. This brief aims to study this kind of bifurcation. A formulation for multi-structure and multi-operating-mode system is described and a systematic procedure for analyzing the non-smooth bifurcation is given. A stand-alone photovoltaic-battery hybrid power system is taken as an example for illustrating the possible non-smooth bifurcation, which is further identified and analyzed with a discrete-time mapping model. Moreover, extensive circuit simulations and experiments verify the theoretical analysis.
Effect of SOI LDMOS Epitaxial Layer Thickness on Breakdown Voltage

Power semiconductors are commonly used in LED bulbs and computer transformers, and are also widely used in industrial equipment, automotive electronic ignition systems, mobile phone battery charging and communication equipment. Power semiconductors are also often used as protective switches as the first goalkeeper for electrical appliances. This paper mainly studies the effect of the epitaxial layer thickness on electric characteristics and finds the suitable epitaxial layer thickness to achieve breakdown voltage more than 700 V to ensure the safety of device usage. The power semiconductors simulated in this study achieve the static breakdown voltage of 805 V for the device based on the epitaxial layer (~15 µm) on SOI substrate. The device based on the epitaxial layer (~3 µm) on SOI substrate achieves the static breakdown voltage of 751 V, and reaches the dynamic breakdown voltage of 704 V under 5 V gate voltages.
Electrocardiogram of a Silver Nanowire Based Dry Electrode: Quantitative Comparison With the Standard Ag/AgCl Gel Electrode

Novel dry electrodes have promoted the development of wearable electrocardiogram (ECG) that is collected in daily life to monitor the ambulatory activity of heart status. To evaluate the performance of a dry electrode, it is necessary to compare it with the commercial disposable silver/silver chloride (Ag/AgCl) gel electrode. In this paper, a silver nanowire (AgNW)-based dry electrode was fabricated for noninvasive and wearable ECG sensing. Signals from the AgNW electrode and the Ag/AgCl electrode were simultaneously collected in two conditions: sitting and walking. Signal quality was evaluated in terms of ECG morphology, R-peak to R-peak interval, and heart rate variability analysis. Quantitative comparisons showed that the AgNW electrode could collect acceptable ECG waveforms as the Ag/AgCl electrode in both the sitting and walking conditions. However, the baseline drift and waveform distortions existed in the AgNW electrode, likely due to electrode motion. If the skin-electrode contact is improved, the dry electrode can be a promising substitute for the Ag/AgCl electrode.
Features and Window Size Selection for Quadcopter Control Using Functional Near-Infrared Spectroscopy

In this paper, different feature combinations and time window sizes for the online/real-time control of a quadcopter using functional near-infrared spectroscopy (fNIRS) is investigated. fNIRS signals are acquired from the prefrontal cortex during the mental arithmetic and puzzle solving tasks. Six most frequently used features of oxy-hemoglobin ($\Delta$ HbO) including mean, peak, minimum, slope, skewness, and kurtosis are calculated in five different window sizes (i.e., 0~2, 0~4, 0~6, 0~8, and 0~10s). All possible 2- and 3-dimensional combinations of features are then formed and classify using linear discriminant analysis. The generated command is used to move quadcopter in a fixed path. The results showed that all combinations of 2- and 3-features containing mean, peak, and minimum values of fNIRS signals yielded significantly higher ($p \lt 0.05$) classification accuracies. Mean, max, and minimum values in 0~2 s give 78% averaged classification accuracy that helps to generate a reliable brain command in a reduced time window for the online control of a quadcopter.
A Unified Approach to the Statistical Convergence Analysis of Frequency-Domain Adaptive Filters

The frequency-domain adaptive filter (FDAF) algorithms are used in many applications due to their computational efficiency and good convergence performance. Many efforts have been made to analyze the convergence behavior of FDAF in the past. However, the previous analyses are based on coarse approximations of overlap-save procedures or small step-size assumptions and hence came to inaccurate predictions of the transient and steady-state performance. Moreover, the rigorous step-size bound in the mean-square sense has not been provided so far. To address these problems, we carry out an extensive analysis of the convergence behaviors for a family of FDAFs based on the overlap-save structure. Using a unified update equation of four FDAFs, the state recursions of the mean weight-error vector and the weight-error covariance matrix are worked out rigorously in the frequency domain, which are then used to investigate the mean-square deviation (MSD) and mean-square error (MSE) during the transient phase. In addition, we obtain the analytical results on the steady-state MSD and MSE, and the bound on the step size for both the mean and mean-square stabilities. Specifically, the analysis presented here does not restrict the regression data to being Gaussian or white. Computer simulations in a system identification scenario confirmed that the proposed theoretical results are much more accurate than the previous approaches.
HOW TO EXPLOIT MOBILITY TO MITIGATE PILOT CONTAMINATION?

To tackle the uplink pilot contamination problem in massive multiple-input multiple-output (MIMO) systems, current researches only relied on the angle of arrival at the base station. However, this information is insufficient when the users share the same scattering environment. In this paper, we propose a novel strategy by exploiting the user mobility. Due to limited scatterers around the users, we first investigate the channel sparsity and derive the corresponding angle-Doppler frequency domain channel power spectrum (AD-CPS). We then propose a method to mitigate the pilot contamination through aligning the AD-CPSs. Compared with the existing works, we further demonstrate the effectiveness of the proposed scheme in supporting more orthogonal pilots when the interfering users exhibit different moving patterns. Simulations verify the superior performance and show that the proposed scheme can serve as an additional decontamination mechanism for the UL pilots in massive MIMO systems.
Sparse Representation Based Approach to Prediction for Economic Time Series

This paper addresses the problem of economic time series forecasting, and a new prediction method is proposed. The method fully capitalizes on the two key technologies, sparse representation, and fuzzy set theory, to handle the stock time series forecasting problems. First, sparse representation is applied to smooth the time series. Then, the fuzzy technology is used to convert time series into fuzzy series. Based on the number of the occurrence of fuzzy sets, the weights are calculated. Finally, the future value of the time series can be forecasted using the weights and inverse transformation of sparse representation. The experimental results show that the proposed method produces more accurate forecasted results.
Finding, Counting, and Highlighting all Triangles in Large Graphs

Graphs are extensively used structure in computer network and various computing applications. Internet, social networks, bioinformatics and many other complicated structures are modeled as graphs. Counting the number of triangles in a graph is an indispensable problem with various applications of modern computing system. Now a day, triangle counting problem of graph is used widely in network analysis. Due to the very large size of networks like the internet and other social networks, the efficiency of algorithms for triangle counting and listing is very important. Counting triangles within graphs with millions and billions of edges requires efficient algorithms which run faster, use a small amount of space and provide accurate estimates of the number of triangles. Here we propose an algorithm that meets all the above criteria. Our algorithm is an enhancement of the existing best algorithms and tries to find and count triangles and to highlight (by JUNG tool) the triangles in huge networks.
Design and Analysis of a DC -DC Buck Boost Converter to Achieve High Efficiency and Low Voltage Gain by using Buck Boost Topology into Buck Topology

This paper proposed a DC-DC buck boost converter which mainly presents the downbeat lower output voltage than the input voltage. It consists of same elements similar to a conventional DC-DC buck converter such as MOSFET switch, paired inductors and switched capacitor. A PSIM simulation has been conducted to compare and contrast the efficiency of the proposed DC-DC buck boost converter and conventional DC-DC buck converter. The result shows the efficiency of the proposed DC-DC buck boost converter is higher than the conventional DC-DC buck converter in terms of both switching frequency and load variation.
In-depth Analysis of Characteristics for an Edge Disordered Sub-10 nm Armchair Graphene Nanoribbon Field Effect Transistor

Graphene nanoribbon is a probable alternative in observing transistor behavior due to its semiconducting properties. One of the fruitful investigations in transistor research is I-V characteristics by using proper bias voltage, in presence of capacitance. In this paper, we will observe the I-V characteristics of Armchair Graphene Nanoribbon (AGNR) by considering the quantum as well as the classical capacitance for two different sizes of AGNR which are 5.04nm and 10.20nm. These two cases will eventually help us concluding a valuable decision in sub-10 nm range based device analysis.
Robust Wide Area Power System Stabilizers Design in Multimachine System based on Backtracking Search Optimization

In this paper the design of a robust wide-area power system stabilizers (WAPSS) taking into account the effect of the time delay using Backtracking Search optimization is presented. In The wide area control design the remote signal is used as input for the power system stabilizer since it has better observability compared to the local signal. However the introduced time delay due to communication links can degrade the performance of the WAPSS in some cases. The proposed BSA simultaneously search for the optimal WAPSS parameters that relocate the weakly damped modes and maximize the time delay for multiple operating conditions to guarantee the robustness. The effectiveness of the WAPSS is tested on the two-area four machine power system. The nonlinear simulation and eigenvalue analysis have revealed the effectiveness of the proposed controller in damping the inter-area oscillations even with a time delay in the remote signals.
Evaluation of MultiZigLoc: Indoor ZigBee Localization System Using Inter-Channel Characteristics

Sensor localization is one of the big problems when building large scale indoor sensor networks. We are developing ZigLoc, a sensor localization system using Wi-Fi (IEEE802.11) APs (access points) as references [1], [2]. ZigLoc measures RSS (received signal strength) of Wi-Fi AP signals to localize ZigBee (IEEE802.15.4) sensor nodes. However, ZigLoc exhibits low accuracy because of inaccurate RSS measured on a single narrow-band ZigBee channel. In this paper, we present a highly accurate sensor localization system MultiZigLoc, which is an extended system of ZigLoc. Our key idea is to employ RSS measured in multiple ZigBee channels in fingerprinting localization. The RSS in multiple channels is dependent on the measured location because ZigBee uses narrow-band channels. Narrow-band ZigBee communication is highly affected by frequency selective fading, whose influence is dependent on channels and locations of both Wi-Fi APs and a sensor. We utilize fingerprints that separately handles RSS in multiple ZigBee channels to employ channel specific features. We conducted initial evaluations using RSS measured in a practical environment. The evaluations reveal that MultiZigLoc improved the localization accuracy by more than 10 points.
FRACTALS AND NONLINEARITY OF OCEAN WAVES

Abstract. From observations using secondary field data and dimension calculations, ocean waves exhibit fractals. Fractals are also hypothesized to have a direct relation with the degree of the waves nonlinearity. We took secondary data of 40 time series of wave record taken from Grays Harbor Wave Refraction Experiment, Washington in 1999. The data are divided into two groups, one group being data taken from the water depth of 25 meters and second group being data taken from water depth of 12 meters. The selection of data is in such a way that the second group is the waves traveling from the first group. We use rescaled range analysis to calculate the fractal dimension of the waves and Goda nonlinearity parameter as a measure of the waves nonlinearity. From the results, we confirm that fractals are a function of waves nonlinearity. Abstrak. Dari data sekunder dan perhitungan dimensi, gelombang laut mempunyai karakteristik fraktal. Bentuk fractal dari gelombang laut diasumsikan mempunyai hubungan langsung dengan ketidaklinearan dari gelombang laut. Untuk pembuktian asumsi ini diambil data pengamatan 40 data seri waktu yang diambil dari eksperimen refraksi di Grays Harbor, Washington tahun 1999. Data ini dibagi menjadi 2 grup, grup pertama adalah data yang diambil di perairan dengan kedalaman 25 meter dan grup kedua diambil dari data yang diambil di perairan dengan kedalaman 12 meter. Pengambilan data di grup kedua adalah sedemikan rupa sehingga data ini adalah berasal dari gelombang yang berjalan dari data grup pertama. Setelah dilakukan perhitungan dimensi kurva dengan menggunakan Analisa Rescaled Range dan mengambil parameter Goda sebagai ukuran ketidaklinearan gelombang laut, didapati bahwa bentuk fraktal gelombang laut berhubungan langsung dengan ketidaklinearan gelombang.
Model and Experiments of Small-Size Vertical Devices With Field Plate

A small-size vertical device with field plate is designed and experimentally realized in this paper. The modulation effect of the field plate causes an enhanced bulk electric field (ENBULF) and improves the breakdown voltage <inline-formula> <tex-math notation="LaTeX">${V}_{\textsf {B}}$ </tex-math></inline-formula>. A 2-D electric field model is developed to give the ENBULF condition corresponding to the maximum <inline-formula> <tex-math notation="LaTeX">${V}_{\textsf {B}}$ </tex-math></inline-formula> and the optimal specific ON-resistance <inline-formula> <tex-math notation="LaTeX">${R}_{ \mathrm{ON},\textsf {sp}}$ </tex-math></inline-formula>. Based on the model, the minimum figure of merit (FOM) (gate charge <inline-formula> <tex-math notation="LaTeX">${Q}_{\textsf {g}}\times \mathrm{\scriptstyle ON}$ </tex-math></inline-formula>-resistance <inline-formula> <tex-math notation="LaTeX">${R}_{ \mathrm{ON}}$ </tex-math></inline-formula>) is discussed for a typical ENBULF device, i.e., the shield-gate vertical double diffused metal–oxide–semiconductor (SG-VDMOS). The calculated results are in good agreement with the simulations. Furthermore, a 35-V SG-VDMOS is analytically designed and experimentally implemented, which obtains a <inline-formula> <tex-math notation="LaTeX">${R}_{ \mathrm{ON},\textsf {sp}}$ </tex-math></inline-formula> of 4.4 <inline-formula> <tex-math notation="LaTeX">$\text{m}\Omega \cdot \textsf {mm}^{2}$ </tex-math></inline-formula> and a gate to drain charge <inline-formula> <tex-math notation="LaTeX">${Q}_{\textsf {gd}}$ </tex-math></inline-formula> of 11.3 nC, respectively. The experiment realizes the minimal FOM and a <inline-formula> <tex-math notation="LaTeX">${R}_{ \mathrm{ON},\textsf {sp}}$ </tex-math></inline-formula> reduced by 28.6% when compared with the conventional “silicon limit. ”
Performance Enhancement in Long-Haul Optical Fiber Communication Using OBP

In this paper investigation were performed to enhance usable bandwidth for coherent optical fiber transmission system. Transmission reach and BER (bit error rate) is improved by use of back propagation technique in both the domains, digital that is based on digital signal processors and in optical domain, based on highly non-linear (HNLF) optical fiber. Using quadrature amplitude modulation (QAM) system for the length of 900 km, experimental investigation were performed for compensation of nonlinearities to evaluate the performance of fiber communication and it is found that significant improvements about 25% can be achieved with the increase in optical SNR. The same BER is maintained at 780 km which was there without OBP at 610 km. Digital back propagation and optical back propagation techniques are compared and it is found that complexity is reduced by implementation of optical back propagation, but restrictions are there on transmission parameters change, which can be resolved by the use of adaptive optical compensation module system.
Hard X-ray/soft gamma-ray Characteristics of the Persistent Emission from Magnetars

In this paper the current status of high-energy research on the hard X-ray characteristics of the persistent emission from magnetars is reviewed. Focus is put on recent intriguing results for 1RXS J1708-40, from phase resolved spectral analysis over a 2 decades wide energy band (~3-300 keV) combining contemporaneous RXTE, XMM and INTEGRAL data. For 1E 1841-045 and SGR 1806-10 we also present updated results. The perspective for future MAXI observations for this source class is also addressed.
An Adaptive Access Control Model Based on Trust and Risk for Medical Big Data

Although big data technology is widely used in the medical field, there is a risk of privacy leakage in the process of medical data share. In terms of this problem, firstly, this paper divides user access behavior into two stages: selecting work objects and selecting what kind of which information to visit; then uses information entropy to measure the confusion degree when users select objects in the process of access; and uses entropy as the input of BP neural network to quantify the risk of access behavior. The risk is fed back to the trust center, which calculates the value of user trust according to the principle that the value of user trust is negatively correlated with the risk. If the user trust value does not meet the requirements of the assigned role, the role will not be assigned. At the same time, if the risk quota is exhausted, the access will be blocked. In this way, access control of medical data is realized.