Miracle-dz/UniFAR-FTUs huggingface dataset:
Efficient Pattern Recognition in Time Series Data

In recent years, Time Series analysis has become one of the most important part of the research area. Classification of time series based on pattern is mainly used in medical and robotics domain. Very large amount of data is generated, which can be stored as time series data. As the size of time series is very large, traditional algorithms are not efficient to recognize and classify patterns extracted from it. To recognize and classify patterns from time series efficiently a new method is proposed in this paper, in which clusters are computed of time series based upon similarity of pattern in them. NN classifier used to classify time series, which uses previously computed cluster center. This method reduces the computations which directly affect the performance of the classification algorithm. The proposed system classifies various time series datasets and is outperforming the previously used tradition methods. For large scale time series, proposed method is implemented on Hadoop framework to achieve high scalability.
Unsupervised Ego-Motion and Dense Depth Estimation with Monocular Video

In recent years, Deep Learning based method for 3-Dimension (3D) geometry perception tasks, like dense depth recovery, optical flow estimation and ego-motion estimation, is attracting significant attention. Inspired by recent advances in unsupervised strategies to learning from video datasets, we present a reasonable combination of constrains and a finer architecture, used for unsupervised ego-motion and depth estimation. Specifically, we introduce our effective neural networks Depth-Net (for monocular depth estimation) and Pose-Net (for ego-motion estimation), which are trained with monocular images. Depth-Net is proposed by us, improving the accuracy of estimation with as few parameters as possible. Finally, extensive experiments are implement on the KITTI driving dataset, proving our method outperforms some state-of-the-art results in unsupervised even supervised method.
The Economic Growth Efficiency of the Beijing-Tianjin-Hebei Urban Agglomeration

At present, China has formed three world-class city agglomerations, they are the Yangtze River Delta, Pearl River Delta and Beijing-Tianjin-Hebei agglomeration. The integrated development of Beijing-Tianjin-Hebei urban agglomeration has received more and more social attentions. Compared with other urban agglomerations, a characteristic of the Beijing-Tianjin-Hebei urban agglomeration shows that the difference of economic development is extremely large. Total factor productivity refers to the part of output increase which can’t be explained by input factors. From domestic and foreign literatures, total factor productivity can be used to measure the quality of economic growth. Based on malmquist index, the change of total factor productivity growth can be decomposed into the change of technological progress, scale effect change and pure technical efficiency change. Therefore, in order to understand the regional difference of economic growth quality, the article makes an empirical study based on the data of 10 cities in Beijing-Tianjin-Hebei urban agglomeration, the time span is from 2000 to 2017. The result shows that there exists a serious regional imbalance of the total factor productivity in the Beijing-Tianjin-Hebei urban agglomeration. In addition, the empirical results also suggest that the difference of total factor productivity mainly comes from the difference of technological progress. At last, according to the empirical results, in order to promote the regional economic integration, this paper puts forward a series of suggestions, such as developing comparative industries, promoting traffic integration, breaking the barriers of elements and so on.
Impact of Different Organic Semiconductor Materials on Performance of Dual Gate OTFT

Organic electronics is predicted as future candidate for organic industries. This paper presents the effect of different material on the performance of dual-gate organic thin film transistor (DG-OTFT) using Atlas TCAD simulator. In this paper Copper (II) phthalocyanine (CuPC), Diketopyrrolopyrole-naphthalene (PDPP-TNT) are considered as p-type organic semiconductor, whereas, F16CuPC and Buckminsterfullerene (C60) as n-type semiconductor for device performance analysis. The analysis is done by varying the material used for the organic semiconducting layer, keeping all the other structural parameters fixed. The devices were analyzed based on their ION/IoFF ratio, maximum drain current ID, threshold voltage VT1, sub-threshold voltage VT2and their trans-conductance GM. The paper compares the results obtained from the analysis to determine the most suitable organic semiconductor (OSC) for dual gate OTFTs.
Indoor Experiment of SAR Interferometry with 79 GHz MIMO Sensor

Synthetic Aperture Radar (SAR) has proven to be useful in surveying, and particularly change detection. When used with interferometric techniques, SAR can detect phase-correlated target movement up to a small fraction of carrier wavelength. Studies have shown a huge advantages in urban area surveying using this technique on satellite-borne SAR sensors over conventional surveying [1]. Some on-going research has also shown possible application of Interferometric Ground-based SAR (GBSAR) sensors that works on a linear rail and around X-band to Ku-band [2]. With the recent advancement in autonomous driving, 77–81 GHz MIMO sensors has been developed for vehicles [3]. While these sensors are not originally intended for SAR, it has been shown a decent SAR image can be formed using these sensor with interferometric measurements. This paper reveals the preliminary result of interferometric SAR imaging using these 77–81 GHz MIMO sensors in a confined indoor environment with corner reflectors.
Circular Formation Algorithms for Multiple Nonholonomic Mobile Robots: An Optimization-Based Approach

This paper revisits the circular formation control problem proposed in [G. S. Seyboth, J. Wu, J. Qin, C. Yu, and F. Allgower, “Collective circular motion of unicycle type vehicles with nonidentical constant velocities,” IEEE Transactions on Control of Network Systems, vol. 1, no. 2, pp. 167–176, Jun. 2014. ] for multiple nonholonomic mobile robots with nonidentical constant forward speeds. Specifically, we study two types of circular formations: First, a circular motion with synchronized/balanced phase configuration; and second, a concentric circular formation with both circular orbits control and phase synchronization/balancing. Existing works on the above problems utilize a fixed-gain control input, which increases the workload of the engineers for selecting favorable algorithm parameters. To reduce this workload, we study the above problems from a new perspective by utilizing optimization methods, based on which two variable-gain control algorithms are proposed such that much greater flexibility on the selection of algorithm parameters is acquired. The global convergence properties of the proposed algorithms are analyzed under some mild assumptions. Both simulations and field experiments are presented to validate the effectiveness of the proposed formation algorithms.
Terahertz-Wave Communication System Using a Traveling-Wave Tube Amplifier

We propose a THz communication system using the combination of high-gain antennas and an amplifier chain. A Cassegrain antenna used as a high-gain antenna enhances a link gain with an antenna gain of 40 dBi or more. Finally, an effective isotropic radiated power is achieved more than 40 dBm. The proof-of-concept demonstration is performed for the realization of THz point-to-point communication systems with moderate spectral efficiency.
Novel Code Filter-Bank Multicarrier Scheme with Low Complexity for OQAM Symbol Transmission and Reception

Filter bank multicarrier with offset quadrature amplitude modulation (FBMC-OQAM) system has low out-of-band emission but needs complex receiver for broadband channel. To address this problem, we propose a new cyclic prefix (CP)-based code FBMC-OQAM system (CC-FBMC-OQAM) with low complexity in this paper. CC-FBMC-OQAM system can be realized within the framework of the standard OFDM system, and perfect recovery (PR) condition is derived in the ideal channel. In order to reduce compute complexity, a low complexity transform of the Fast Walsh-Hadamard and Fourier transform (FWFT) is adopted and it uses a fast orthonormal unitary transform to calculate both the discrete Fourier transform (DFT) and the Walsh-Hadamard transform (WHT). Theoretical analysis and simulation results show that, compared to the C-FBMC-OQAM system and orthogonal frequency division multiplexing (OFDM) system, the computational complexity of proposed CC-FBMC-OQAM system is reduced substantially with almost same bit error rate (BER) performance in doubly-flat channel. Moreover, the BER performance of proposed CC-FBMC-OQAM system slightly outperform conventional C-FBMC-OQAM system in doubly-selective channel.
Secure Neighbor Discovery Using Symmetric Link Management in Tactical Sensor Networks

Tactical Wireless sensor networks (WSNs) provide a low-signature communications system that can be used for a wide variety of military applications. However, these networks are vulnerable to intrusion and must balance security with performance and longevity. The neighbor discovery process in a WSN is vital for nodes to maintain network connectivity, but it introduces security vulnerabilities. In addition, existing protocols for securing the neighbor discovery process use public key encryption (PKE), which is computationally expensive for low-powered, resource-constrained IEEE 802.15. 4 enabled sensor devices. Therefore, a lightweight algorithm to secure the neighbor discovery process is necessary to prevent unauthorized nodes from accessing network data and resources. We develop a key management algorithm that modifies the commonly used Neighbor Discovery Protocol (NDP) and Secure Neighbor Discovery (SEND) protocol. We replace PKE in NPD and SEND with a symmetric encryption algorithm, AES, to allow for energy efficiency. In addition, we implement the Diffie-Hellman key exchange algorithm for symmetric key management. We simulate our algorithm in MATLAB to demonstrate its effectiveness in securing the neighbor discovery protocol while providing energy and message efficiency and key security.
Discovering Transportation Mode of Tourists Using Low-Sampling-Rate Trajectory of Cellular Data

Transportation mode detection plays an important role in transport planning and disclosing the contextual information of an individual or a group. Most existing approaches for inferring the transportation mode rely on GPS data collected from the mobile phone users, which can get more precise detection rate but in a lower scale. In this paper, we propose a framework based on data from cellular network, i.e., call detail records (CDRs), to determine the motorized transportation mode of tourists. In order to reduce the uncertainty of the low-sampling-rate trajectories getting from CDRs of tourists, an algorithm called spatial and temporal dynamic time warping (ST- DTW) is presented to conduct route matching between tourists trajectories and various routes of different transportation modes. Additionally, for a tour group, a trajectory aggregation method is used to merge the trajectories in one group so as to improve the accuracy detection. Finally, a number of interesting insights about travel behaviors of tourists in Hainan Province are given.
MEMS Surface Coating Condition Monitoring via Nonlinear Tapping of Resoswitches

A MEMS resoswitch-enabled surface coating condition-monitoring device is demonstrated as a proof of concept that successfully detects the existence of molecule coated on the structure surface. In particular, a CMOS-MEMS clamped-clamped beam (CC-beam) resoswitch exhibits a distinguishable change in the tapping bandwidth of the frequency response against different surface conditions while operating in the nonlinear cold switching mode. By salinizing the surface with (1H, 1H, 2H, 2H)-per-fluorodecyltrichlorosilane (CF3 (CF2)7(CH2)2SiCl3, FDTS), the resoswitch presents a tapping bandwidth extended from 17.37 kHz to 29.75 kHz due to lowered adhesion forces. The resoswitch-based surface condition could be employed to enable in situ monitoring of, for example, the anti-stiction coating often used in MEMS motion sensors.
Feature Extraction of Hyperspectral Images With Semi-supervised Sparse Graph Learning

We propose a semisupervised sparse graph learning (SSGL) method for feature extraction of hyperspectral remote sensing imagery in this paper. The proposed SSGL method aims to build a semisupervised sparse graph that can maximize the class discrimination and preserve the local neighborhood information by combining labeled and unlabeled samples. In our semisupervised sparse graph, we connect labeled samples according to their label information and sparse representation, connect unlabeled samples by sparse representation which set unlabeled training samples set as dictionary. Moreover, by setting sparse connections between labeled sample and unlabeled samples, the label information can be well propagated from labeled samples to unlabeled samples. In this way, the similarity of data points can be well modelled in the spectral feature space, and the data distribution characteristics can be better expressed. Experimental results on real hyperspectral images (HSIs) demonstrate the advantages of our method compared to some related feature extraction methods.
Significance of Pass Transistor Logic in Organic Electronic Circuits

In the field of renewable energy harnessing Organic electronics has opened enormous possibilities as it is more environment friendly in comparison to silicon. Moreover organic electronics provides numerous advantages like flexibility of the substrate, low cost raw material, low cost fabrication, simple fabrication steps and flexible device. These advantages open a whole new world of low cost electronics display devices and much more. But the larger size of organic transistor and moderate mobility of organic materials serves as challenge for us. But a probable solution to these problems can be found in pass transistor logic (PTL) design. Since the overall size of the circuit also depends on the number of transistors in the circuit and not merely on the size of individual circuit. Therefore by drastically reducing the transistor count in the circuit we can minimize the size of the circuit. In addition to it the propagation delay and interconnect length is also optimised by using PTL architecture along with power dissipation.
Machine Learning Based DDos Detection Through NetFlow Analysis

Distributed Denial of Service (DDos) has been a lasting severe threat to Internet, which is evolving both in technique and traffic volume recently. Many traditional detection methods fail due to their limitations in real-time, complexity or universality. Therefore, it is necessary to explore how to timely detect different kinds of DDOS by utilizing simple traffic sampling data such as NetFlow in high speed networks up to Tbps bandwidth. In this paper, we put forward a scheme to identify DDos traffic with NetFlow feature selection and machine learning. Firstly, we extract adaptive flow-based features and pattern-based features from sampling NetFlow data in real-time. Then we build a detector by RandomForest and evaluate it by using a research lab network trace which contains benign traffic and simulated DDos traffic of different kinds by popular DDos tools. Experiment results show that our method achieves an average accuracy of more than 99% and a false-positive less than 0.5%. Besides, our method is valid for DDos means such as stealthy DDos attack so it is more universal that typical traditional methods. Finally, we apply our detector on the real-world NetFlow logs provided by a large ISP, and measure the characteristics of DDos in several dimensions. This also proves that our detector is applicable for real-world network.
Analysis. Modelling and Design of Resonant Dual Active Bridge Isolated Bidirectional dc/dc Converter for Minimizing Cold Start Effect of Fuel Cell Vehicle

Effect of air and sound pollution has been increases since last few decades due to internal combustion engines and there is a lesser impact of electrical apparatus in automobile sector. Moreover, conventional energy sources are faster exhaustion sources and have been severe impact over ozone layer. The usage of electrical components is increases exponentially in electric vehicles over last decade due to advances in power electronics. In this article, performance comparison of bi-directional dc/dc converters over switching loss reduction, efficiency, ripple analysis, cost and size. Those dc/dc converters are Generic Duel Active Bridge (GDAB-IBDC) and Resonant Dual Active Bridge (RDAB-IBDC) isolated bidirectional dc/dc converters. The GDAB-IBDC converter is simple and its controller is not complex compare to resonant dc/dc converter. The simulation is carried out over PSCAD software with 10 ohm constant resistive load. The resonant dc/dc converter has excellent features compare to generic dc/dc converter like higher switching frequency, less switching losses, higher efficiency, more possibility of soft switching of both bridges and lesser circulating current.
A Static Analysis Model for Implicit Information Leakage in Android Application

The privacy information leakage can be divided into explicit and implicit information leakage. The detection of IIF (implicit information flow) is an important task in Android Security research. The IIF mechanisms are significantly different from traditional information leakage, because implicit information leakage adopted program structural changes in the way information is leaked. We find the correlation between basic blocks, control structures and expressions of the three different levels objects, proposal SRFM (Structure-Related Flow Model) to describe the relationship between the implicit flow and the control structure. A prototype system TSDroid (Structure-Related Flow Droid) is developed. The experiment shows that TSDroid can detect the implicit information leakage with more efficiency and higher precision than other traditional methods.
A Reference Buffer with High-Efficiency for High-Speed and High-Precision Switched-Capacitor ADCs

A fully integrated reference buffer with high-efficiency for high-speed and high-precision Switched-capacitor ADCs is presented. To reduce hardware and power comsumption, the slow feedback loop and reference generation circuit are combined. And an improved stacked source follower is used to provide low output impedence with low power. The efficient reference buffer is applied to a 12-bit 1Gsps pipeline ADC with amplification phase less than 350ps. The power dissipation of the proposed reference buffer is 56.25mW with 2.5V supply voltage.
Hybrid GEO and IGSO Satellite Constellation Design with Ground Supporting Constraint for Space Information Networks

In space information networks, satellites are generally in high speed orbit motion. In order to obtain better spacial and temporal coverage performance, satellites should cooperate with each other as a constellation. Previous works on constellations mainly focus on global seamless coverage using fewer satellites. However, like most countries, it is hard for China to build ground stations in overseas, and the geostationary Earth orbit position resource is scarce. In this paper, we investigate the constellation design problem with restricted ground supporting. We first proposes a “backbone network + enhanced network” hybrid constellation design approach. Then a hybrid “4GEO+SIGSO” constellation is designed using the proposed approach, and the coverage performance of this constellation is analyzed in detail. Simulation results show the proposed approach can realize global seamless coverage only using a small number of satellites. Furthermore, the proposed hybrid constellation meets the coverage demand only relies on ground stations inside China.
Compacted 8 MIMO Antenna Design for Wi-Fi AP

This paper presents a Wi-Fi dual-band MIMO antenna design, covering 2.4 GHz-2.5 GHz and 4.9 GHz-6 GHz, suitable for the global Wi-Fi band. In order to reach the area of 140 × 120 mm2, place 8 pieces of antennas and reach sufficient isolation degree, and close to omni-directional pattern, make AP can have enough radiation pattern quantity to meet the requirement of MIMO communication. The low inductive performance of the loop antenna effectively reduces the antenna resonant frequency shift subject to the surrounding matter, can produce good isolation effect, and to achieve adequate bandwidth requirements. The dipole antenna structure is simple and the bandwidth is easily achieved by placing the same direction to enhance the low-band antenna gain. The overall structure of the antenna compact, size 140 × 120 × 1.6 mm3, can be used as the AP embedded antenna. The use of two dipole antennas covers the low-frequency band in the IEEE 802.11 specification and enhances the low-band antenna gain by placing the same direction. The six-loop antenna covers the high-frequency band in the specification. The low-inductance performance of the loop antenna is matched with the vertical orientation of each other, making the overall size more compact and the high-band isolation at least 20 dB. The measured ECC less than 0.2 have been noticed over the two frequency bands.
Towards Optimization of Open Ended Contact Probes for Breast Cancer Diagnosis

Development of new modalities for breast cancer detection have been a research interest due to the drawbacks of existing diagnostic technologies such as imaging with ionizing waves. In particular, microwave imaging has been investigated in the literature as a new modality for breast cancer detection. Microwave imaging is a promising technique due to the high dielectric contrast between benign and malignant lesions. With this motivation, the dielectric properties of the benign and malignant breast tissues were measured and such measurements have been performed with the open ended contact probes. The open ended contact probe technique widely used in laboratory environment to characterize the dielectric properties of materials with high permittivity and conductivity due to the advantages such as broad band measurement capabilities and limited sample size requirements. The utilization of the open ended contact probe technique as a breast cancer diagnostic technology have been previously envisioned in the literature. One such application is integration of these probes to biopsy guides to diagnose whether the breast lesions are benign or malignant. However, due to the poor measurement accuracy and repeatability the utilization of the technique as a diagnostic technology was not realized. The drawbacks of the technology mostly stem from the mathematical approaches and the deviations from the initial calibration conditions. In this work, to increase the accuracy of the open ended contact probe measurement technique, the probe structure is redesigned by removing the microwave connections and integrating the probe with the RF cable. Probe simulations are performed with Computer Simulation Technology (CST). The probe is tested with both known materials and more complex environments such as methanol and phantom experiments. Oil-in-gelatine dispersion phantom materials are composed and measured with the designed probe. Probes with small aperture diameters were also evaluated to investigate the potential practical utilization of such probes. Dielectric properties are calculated with in-house dielectric property retrieval algorithm. A good agreement is obtained with the reference data.