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Test case prioritization (TCP) has been widely studied in regression testing, which aims to optimize the execution order of test cases so as to detect more faults earlier. TCP has been divided into white-box test case prioritization (WTCP) and black-box test case prioritization (BTCP) . WTCP can achieve better prioritization effectiveness by utilizing source code information, but is not applicable in many practical scenarios (where source code is unavailable, e.g., outsourced testing). BTCP has the benefit of not relying on source code information, but tends to be less effective than WTCP. That is, both WTCP and BTCP suffer from limitations in the practical use. To improve the practicability of TCP, we aim to explore better BTCP, significantly bridging the effectiveness gap between BTCP and WTCP. In this work, instead of statically analyzing test cases themselves in existing BTCP techniques, we conduct the first study to explore whether this goal can be achieved via log analysis. Specifically, we propose to mine test logs produced during test execution to more sufficiently reflect test behaviors, and design a new BTCP framework (called LogTCP), including log pre-processing, log representation, and test case prioritization components. Based on the LogTCP framework, we instantiate seven log-based BTCP techniques by combining different log representation strategies with different prioritization strategies. We conduct an empirical study to explore the effectiveness of LogTCP. Based on 10 diverse open-source Java projects from GitHub, we compared LogTCP with three representative BTCP techniques and four representative WTCP techniques. Our results show that all of our LogTCP techniques largely perform better than all the BTCP techniques in average fault detection, to the extent that they become competitive to the WTCP techniques. That demonstrates the great potential of logs in practical TCP.

The series electro-hydraulic hybrid powertrain can improve the power characteristics of battery rail vehicles (BRVs) while also extending battery life and increasing vehicle mileage. A novel electric motor start-up method using the hydraulic pump/motor to reversely drive the permanent magnet synchronous motor (PMSM) to restart at a speed is proposed based on the energy reverse transfer characteristics between the electric motor and hydraulic pump/motor. PID controls the reverse driving process of the hydraulic motor. The zero vector voltage (ZVV) method is used to determine the initial speed and rotor position of the motor restart at a speed. The electric motor speed control adopts the speed sensorless space vector pulse width modulation (SVPWM) control based on the back-electromotive force (EMF) integration method. The simulation models are carried out in MATLAB/Simulink and AMESim and built a special test platform. The results show that the method for controlling electric motor restart is feasible and effective. The start-up current of the electric motor is related to its initial speed. The closer the initial speed is to its target speed, the smaller its start-up current is, the faster the electric motor reaches the stable target speed.

A band-limited magnitude-selective affine (MSA) function-based model is proposed for digital predistortion (DPD) of broadband power amplifiers (PAs) in 5G millimeter-wave frequency band. The new model is derived from the band-limited canonical piecewise linear function-based model by employing MSA functions, which can obviously reduce the number of multiplication operations and the model complexity. Experimental results show that the proposed model gives better normalized mean square error and DPD performance in comparison with some existing models when a broadband PA is excited by a 5G new radio (NR) signal of 400-MHz bandwidth at 28-GHz band.

An antipodal linearly tapered slot filtenna (ALTSFA) with diverse split-ring resonators (SRRs) is proposed. The ALTSFA is actually an antipodal linearly tapered slot antenna (ALTSA) fed by a substrate integrated waveguide (SIW) whose cut-off characteristic is utilized to obtain a lower-band suppression. A broad-coupled complementary SRR (BC-CSRR) and 11 SRRs on the ALTSA are used to achieve an upper-band suppression. Hence, filtering function with wide stopbands is achieved without enlarging its size and deteriorating the radiation performance. A prototype of the proposed ALTSFA was fabricated and measured, and a bandwidth ranging from 23.5 to 27.5 GHz, a maximum gain of 10 dBi, and a maximum out-of-band suppression of 20.55 dB are observed, validating its good performance. The proposed ALTSFA can be a promising candidate for compact 5G/B5G millimeter-wave communication system.

In this letter, a three-dimensional ground coplanar waveguide (3D-GCPW) structure is proposed as a broadband planar transition between the conventional GCPW and substrate integrated coaxial line (SICL). The proposed 3D-GCPW contains a 3-D central conductor constructed by two copper layers which are connected together by metallized blind vias and two side ground planes. Its characteristic impedance is mainly determined by the width of the 3-D central conductor and the gap to the side ground plane; thus, the requirement for machining accuracy of metallized blind vias in 3D-GCPW can be reduced during the machining process. A back-to-back structure of the 3D-GCPW transition is fabricated by a multilayer printed circuit board (PCB) process and measured to validate the good performance. The experimental results show that the proposed 3D-GCPW transition exhibits a reflection coefficient less than −10 dB and an acceptable insertion loss within dc to 42 GHz, making it promising for high-performance multiple-channel transceiver or massive integrated applications.

A high-gain dual-band resonant cavity antenna (RCA) for the fifth-generation (5G) millimeter-wave (MMW) communications is presented in this letter. The proposed antenna provides the high gain and large gain-bandwidth product over the 28 GHz band and the 38 GHz band. The heights of the second- and third-order resonant in the RCA are optimized for dual-band operation. Improvements on the gain and the bandwidth are achieved in both bands when stepped rings are added. The gain is further increased with a circular patch on a partially reflective surface, which is made by a substrate of high permittivity. Finally, a prototype is designed, simulated, and verified through measurement. Good performance is achieved: in the 26.5–28 GHz band, the bandwidth is 5.5% and the peak gain is 20.3 dBi; in the 37.5–39.4 GHz band, the bandwidth is 4.9% and the peak gain is 20.4 dBi. The proposed antenna has the features of low cost and easy fabrication as well.

In this article, novel millimeter-wave (mmWave) filtennas (filtering antennas) are proposed to realize compact size and low insertion loss for 5G applications. It is achieved by employing eighth-mode substrate-integrated waveguide (EMSIW) cavities fully shielded by metallized vias and cover as resonators, which are named as fully shielded EMSIW (FSD-EMSIW) cavities. Interdigital coupling between cavities is introduced in order to obtain higher coupling strength for wideband operation. The proposed single-polarized antenna consists of a feeding stripline, two FSD-EMSIW cavities, and two stacked square patches, generating the four-order filtering antenna response. Furthermore, this design has been extended to realize a dual-polarized filtenna by employing double sets of feeding network. For demonstration, single-/dual-polarized filtenna prototypes were fabricated and measured, the measured results show that the 5G mmWave band (24.25–29.5 GHz) can be covered with average gains of 4.5 dBi. Good bandpass filtering response is also observed. Finally, to validate the proposed idea in array applications, a 16-element filtenna array is designed and measured with good performance.

In this paper, to address the problem of automatic positioning and grasping of bolster spring with complex geometric features and cluttered background, a novel image-based visual servoing (IBVS) control method based on the corner points features of YOLOv3 object detection bounding box is proposed and applied to the robotic grasping system of bolster spring. The YOLOv3 object detection model is used to detect and position the bolster spring and then based on the corner points features of the bolster spring bounding box, the IBVS controller is designed to drive the end effector of the robot to the desired pose. This method adopts the approach-align-grasp control strategy to achieve the grasping of the bolster spring, which is very robust to the calibration parameter errors of the camera and the robot model. With the help of Robotics and Machine Vision Toolboxes in Matlab, IBVS simulation analysis based on feature points is carried out. The results show that it is reasonable to use the corner points of the object detection bounding box as image features under the initial pose where the image plane is parallel to the object plane. The positioning and grasping experiments are conducted on the robotic grasping platform of bolster spring. The results show that this method is effective for automatic positioning and grasping of bolster spring with complex geometric features and cluttered background, and it has strong robustness to the change of illumination.

In recent years, human motion recognition, as an important application of the intelligent perception of the Internet of Things, has received extensive attention. Many applications benefit from motion recognition, such as motion monitoring, elderly fall detection, and somatosensory games. Several existing RF-based motion recognition systems are susceptible to multipath effects in complex environments, resulting in lower recognition accuracy and difficulty in extending to other scenarios. To address this challenge, we propose RF-Motion, a device-free commercial off-the-shelf (COTS) RFID-based human motion recognition system that can detect human motion in complex multipath environments such as indoor environments. And when the environment changes, RF-Motion still has high recognition accuracy, even without retraining. In addition, we use data slicing to solve the problem of discontinuity in the time domain of RFID communication and then use the synthetic aperture (SAR) algorithm to obtain the fingerprint feature matrix corresponding to each motion. Finally, the dynamic time warping (DTW) algorithm is used to match the prior motion fingerprint database to complete the motion recognition. Experiments show that RF-Motion can achieve up to 90% accuracy for human motion recognition in an indoor environment, and when the environment changes, it can still reach a minimum accuracy of 87%.

This letter reports a strategy of full-digital arrays with nonreciprocal transmitting (Tx) and receiving (Rx) beam patterns, for the first time, for 5G/6G wireless communications. The proposed full-digital array contains a smaller number of Rx channels than that of the Tx channels. The unequal number of Tx and Rx channels makes the transmitting and receiving patterns asymmetrical, which would not only release the burden of data processing but also reduce the hardware cost and power consumption of the entire system. Importantly, as compared with conventional large-scale beamforming arrays, the proposed strategy will not deteriorate the range of coverage at an instantaneous time. A 64-element full-digital beamforming array prototype was designed, fabricated, and characterized for a proof-of-concept demonstration.

A novel wideband magnetoelectric (ME) dipole antenna with dual circular polarization and unidirectional radiation is proposed in this letter. The proposed antenna is based on two perpendicular sub-ME dipoles realized by four V-shaped patches and four V-section columns, and each of them is composed of an electric dipole and a magnetic dipole in parallel. Fed by two simple Γ-shaped feeds, 90° phase difference between the electric dipole and the magnetic dipole in each of the sub-ME dipoles is achieved, hence the dual-circularly polarized radiation is generated. Wide impedance bandwidth is obtained in virtue of the two kinds of dipoles being excited simultaneously. The 3 dB axial-ratio (AR) bandwidth is enlarged by optimizing the V-section columns and a circular cavity. Besides, the port isolation is apparently enhanced by adding slits on the patches and elaborating different spacings between each feed and its two-sided columns. Measured results show that the proposed antenna has many appealing properties, such as a unidirectional radiation pattern, an impedance bandwidth (reflection coefficients ≤–10 dB and port isolation ≥ 10 dB) of 51.1% and a 3 dB AR bandwidth of 41.9%.

In recent years, many test case prioritization (TCP) techniques have been proposed to speed up the process of fault detection. However, little work has taken the efficiency problem of these techniques into account. In this paper, we target the Greedy Additional (GA) algorithm, which has been widely recognized to be effective but less efficient, and try to improve its efficiency while preserving effectiveness. In our Accelerated GA (AGA) algorithm, we use some extra data structures to reduce redundant data accesses in the GA algorithm and thus the time complexity is reduced from $\mathcal{O}(m^2n)$ to $\mathcal{O}(kmn)$ when $n > m$, where $m$ is the number of test cases, $n$ is the number of program elements, and $k$ is the iteration number. Moreover, we observe the impact of iteration numbers on prioritization efficiency on our dataset and propose to use a specific iteration number in the AGA algorithm to further improve the efficiency. We conducted experiments on 55 open-source subjects. In particular, we implemented each TCP algorithm with two kinds of widely-used input formats, adjacency matrix and adjacency list. Since a TCP algorithm with adjacency matrix is less efficient than the algorithm with adjacency list, the result analysis is mainly conducted based on TCP algorithms with adjacency list. The results show that AGA achieves 5.95X speedup ratio over GA on average, while it achieves the same average effectiveness as GA in terms of Average Percentage of Fault Detected (APFD). Moreover, we conducted an industrial case study on 22 subjects, collected from Baidu, and find that the average speedup ratio of AGA over GA is 44.27X, which indicates the practical usage of AGA in real-world scenarios., IEEE Transactions on Software Engineering, 2021

The identification of innovative gene biomarkers with clinical efficacy is warranted for the treatment of acute myocardial infarction (AMI). The current study sought to screen potential target genes in AMI via bioinformatic analysis and analyze their effects on cardiomyocyte apoptosis. The differentially expressed long non-coding RNAs (lncRNAs) of AMI were screened, and the downstream microRNAs (miRNAs) and mRNAs of lncRNA antisense for X-inactive-specific transcript (lncRNA TSIX) were predicted accordingly. The diagnostic relationship between the 12 differentially expressed lncRNAs and AMI was analyzed by receiver operating characteristic (ROC). Next, the expressions of 12 lncRNAs, including miR-34a-5p and retinol binding protein 2 (RBP2) were all detected. The targeting relationships of miR-34a-5p with lncRNA TSIX and RBP2 were verified. AMI model was established and treated with Ad-TSIX and/or agomiR-34a-5p to evaluate the cardiac function and cardiomyocyte apoptosis of AMI mice. LncRNA TSIX was identified as the most differentially expressed lncRNA in AMI. Our findings revealed that LncRNA TSIX could function as an AMI diagnostic marker. LncRNA TSIX could target miR-34a-5p and miR-34a-5p could target RBP2. Upregulation of lncRNA TSIX could ameliorate cardiac injury inflicted by AMI and mitigate cardiomyocyte apoptosis. Upregulation of miR-34a-5p reversed the effect of lncRNA TSIX overexpression to ameliorate cardiomyocyte apoptosis in AMI mice. Overall, the overexpression of lncRNA TSIX inhibits cardiomyocyte apoptosis by competing with RBP2 to bind to miR-34a-5p and promoting RBP2.

A 2-D simplified memory polynomial (2D-SMP) model is proposed for concurrent dual-band power amplifiers (PAs) in this letter. The derivation of the proposed model is similar to that of the 2-D modified memory polynomial (2D-MMP) model. The 2D-SMP model consists of an in-band part and a cross-band modulation part without the envelope factors, which exist in the 2D-MMP model. Theoretical analysis shows that it has moderate complexity but higher modeling accuracy than the 2D-MMP model. The simple least square algorithm can be used to extract the model coefficients, and the additional binary search algorithm for the best envelope factor is not needed. The experimental results show that the 2D-SMP model can achieve higher model accuracy and better digital predistortion (DPD) performance than the 2D-MMP model when a dual-band PA is excited by a combined dual-band long-term evolution signal.

In this paper, a simple fast electromagnetic (EM) optimization method for substrate integrated waveguide (SIW) filters is presented. The feature parameter deviations are estimated by direct response approximation based on the feature parameter model with few times quasi-Newton method. The parameter extraction process is more concise than the parameter identification techniques based on the rational polynomial model and can be used for lossless networks as well as lossy networks. The dimension correction is based on the Jacobian matrix which relates the physical dimensions and the feature parameters. An analytical general mapping model for SIW filters is extracted and applied to generate and update the Jacobian matrix for the first time. The extracted model can be directly used for SIW filter design without repeated extraction. This helps to minimize the number of EM simulations and avoid extra work for model extraction. Using general mapping model can overcome the robustness issue introduced by Broyden update methods. The number of EM simulations required to meet the specifications can be significantly reduced. The effectivity and robustness of the proposed method is validated by two design examples: a 10-order SIW Chebyshev filter and a 5-order SIW cross-coupled filter. The proposed method exhibits low complexity, good stability, good convergence speed and the ability to avoid being trapped in local minimum.

A wideband substrate integrated waveguide (SIW) cavity-backed Ring slot antenna is proposed in this paper. The ring slot mode and the TE210 mode of the SIW cavity are excited by dual slots fed by a TE20 Mode SIW transmission line. A 1×4 array is designed and fabricated. The proposed antenna has a measured impedance bandwidth of 25.89%(from 23.2 GHz to 30.1 GHz). The measured realized gain is above 9 dBi in the whole band. The proposed antenna is suitable for 5G millimeter-wave applications.

In this talk, a brief review on the newly proposed concept of asymmetric millimeter wave (mmWave) massive multi-input and multi-output (MIMO) system for beyond 5G(B5G) and 6G mobile communications is presented, including the system architecture, requirements for integrated circuits (ICs) design etc., and some research advances.

A fast electromagnetic optimization method for hairpin filters using model-based deviation estimation is presented in this paper. An analytical mapping model between the feature parameters and the physical dimensions of the hairpin filters is established. The design dimension errors are converted from the feature parameter deviations by using the Jacobian matrix of the general model. A five order hairpin filter is demonstrated, which converges after six iterations.

With the increasing adoption of Deep Learning (DL) models in various applications, testing DL models is vitally important. However, testing DL models is costly and expensive, e.g., manual labelling is widely-recognized to be costly. To reduce testing cost, we propose to select only a subset of testing data, which is small but representative enough for a quick estimation of the performance of DL models. Our approach, DeepReduce, adopts a two-phase strategy. At first, our approach selects testing data for the purpose of satisfying testing adequacy. Then, it selects more testing data to approximate the distribution between the whole testing data and the selected data by leveraging relative entropy minimization. We evaluate DeepReduce on four widely-used datasets (with 15 models in total). We find that DeepReduce reduces the whole testing data to 7.5% on average and can reliably estimate the performance of DL models.

This paper presents a low-profile shared-aperture antenna for 3.5/28 GHz applications. The antenna utilizes a 3.5 GHz patch with a double-layer structure to integrate a 28 GHz 4⨯2 substrate integrated waveguide (SIW) slot array antenna. The array consists of four 2-element subarrays and is excited by four ports below the patch to realize beam steering. For feeding the subarray, this paper introduces a SIW vertical interconnection structure which loads the patch with shorting vias. By adjusting the loading position and the patch dimension, the influence brought by those vias can be minimized. Therefore both antennas can share the same aperture with low mutual interference. The antenna prototype is fabricated and achieves a gain of 6.3 and 11.6 dBi at 3.5 and 28 GHz, respectively. Besides, the radiation beam at 28 GHz of the prototype is steerable within +/-30° on the E-plane.

This paper presents a large-frequency-ratio shared-aperture antenna with enhanced suppression of cross-polarization. Based on the previously reported topology, the antenna integrates a 3.5 GHz dipole antenna with a 28 GHz 4-element array. The array employs a double-layer dipole element fed by a stripline to counteract the cross-polarization components. Combined with the separate feeding network of the substrate integrated coaxial line, the array can generate a steerable millimeter-wave beam. The experimental results indicate that the antenna has good performances in both frequency bands, including a cross-polarization lower than −24.5 dB.

In this paper, the development of a millimeter-wave hybrid beamforming (HBF) transceiver system for 5G millimeter-wave multiple-input-multiple-output (MIMO) communication is presented. The developed transceiver system is operated at 28-GHz band in the time division duplex (TDD) mode, with 500-MHz signal bandwidth. To implement high beamforming accuracy, a phased-array-based HBF transceiver with high-precision phase shifting network (PSN) at intermediate-frequency (IF)-paths is proposed. The designed PSN has 8-bit phase resolution within 360° range and 0.13-dB amplitude variation. With the use of such low-cost 8-bit PSN, this HBF transceiver system achieves 0.6° beam resolution and a good RF transceiver performance. In addition, under the over-the-air MIMO communication test with two data streams, the error vector magnitude (EVM) of the received signals at two user equipment (UE) is 2.58% and 2.34%. The high-data rate millimeter-wave communication and MIMO performance of this HBF are verified.

A planar circularly polarized substrate integrated waveguide (SIW) stacked patch antenna array consisting of four sequential-rotation (SR) subarrays is presented for $Ka$ -band applications. Antenna element is realized based on a pair of stacked cavities by the combination of a driven patch layer and a parasitic patch layer, which are formed by a shorted square patch and multiple identical stacked square patches, respectively. Each subarray consisting of two pairs of elements, excited by a coplanar waveguide (CPW) network with four metallic vias, is well matched to a novel SIW SR feeding network. A narrow transverse coupling slot, a semiopening resonant cavity, two pairs of inductive vias, and an inductive window are introduced in the SIW-based feeding network to implement functions of phase shifter, impedance matching, and power divider in the two layers. By employing the proposed SR feeding network, the CPW network, and the four subarrays, the excellent performance of the array is realized. To verify the design, a prototype is fabricated and measured, which demonstrates a −10 dB impedance bandwidth of 29.6%, a 3 dB axial ratio bandwidth of 25.4%, and a peak gain of 20.32 dBic.

A 64-channel massive multiple-input multiple-output (MIMO) transceiver with a fully digital beamforming (DBF) architecture for fifth-generation millimeter-wave communications is presented in this paper. The DBF-based massive MIMO transceiver is operated at 28-GHz band with a 500-MHz signal bandwidth and the time division duplex mode. The antenna elements are arranged as a 2-D array, which has 16 columns (horizontal direction) and 4 rows (vertical direction) for a better beamforming resolution in the horizontal plane. To achieve half-wavelength element spacing in the horizontal direction, a new sectorial transceiver array design with a bent substrate-integrated waveguide is proposed. The measured results show that an excellent RF performance is achieved. The system performance is tested with the over-the-air technique to verify the feasibility of the proposed DBF-based massive MIMO transceiver for high data rate millimeter-wave communications. Using the beam-tracking technique and two streams of QAM-64 signals, the proposed millimeter-wave MIMO transceiver can achieve a steady 5.3-Gb/s throughput for a single user in fast mobile environments. In the multiple-user MIMO scenario, by delivering 20 noncoherent data streams to eight four-channel user terminals, it achieves a downlink peak data rate of 50.73 Gb/s with the spectral efficiency of 101.5 b/s/Hz.

A low-profile circularly polarised (CP) antenna with conical-beam radiation pattern is presented. The proposed antenna consists of a monopolar patch antenna fed by a probe in the centre and a ring-shaped array formed by eight modified parasitic patch elements. Two resonant modes of the monopolar patch which connects to a ground plane by a set of conductive shorting vias are utilised to achieve wide impedance bandwidth. A CP conical-beam radiation pattern is formed by loading the designed array. Loop current and slot resonant mode are employed to discuss the operating principle. A parametric study is carried out for the detailed design concept illustration. To verify the design, a prototype has been fabricated and measured, which shows a low profile of 0.059 λ 0 , a maximum gain of 7.45 dBic, a 10-dB impedance bandwidth of 23.1%, a 3-dB axial ratio bandwidth of 9.6% and a good conical-beam radiation pattern.

A low-profile substrate-integrated waveguide (SIW) cavity-based antenna with conical-beam circularly polarized (CP) radiation is presented. Conical-beam CP radiation is obtained by the combination of a radial current source and a loop current source, which are produced by a shorted monopole patch and an annular array, respectively. The proposed annular array configuration is designed by combining multiple identical customized parasitic patch elements arranged around the monopole. Phase compensatory lines and shorted annular ring slots are introduced in the array to tune phase difference of two current sources and to generate in-phase currents on the elements, respectively. All antenna elements are simultaneously excited within a center-fed SIW cavity. In order to fully picture the operating mechanism, we analyze the wide impedance and axial-ratio (AR) bandwidths based on an equivalent circuit model and an electromagnetic theory. Then, parametric studies are carried out for a detailed design illustration. To verify the design, a prototype has been fabricated and measured, which shows a stable conical-beam radiation and good performance including: a low profile of $0.062\lambda _{0}$ , a 10 dB impedance bandwidth of 20.4%, a 3 dB AR bandwidth of 17%, a maximum gain of 8.25 dBic, and an advantage of large ground compatibility.