nils-herrmann/clean_scirepeval huggingface dataset:
Investigation of Transmission Losses in a Dielectric Slab Waveguide at Terahertz Frequencies

In this paper, a theoretical analysis of transmission losses for the TE, TM modes of a dielectric slab waveguide at terahertz frequencies is performed. Equations are presented for the field components, dispersion characteristics, core power confinement factor and attenuation constant as a function of the operating frequencies, waveguide dimensions and material constants. The calculation curves covering frequencies and dimensions for the given material constants in the THz region are presented. The investigation results show that, the loss of the slab waveguide increases at a rate proportional to approximately f, which is much slower than that of rectangular metallic waveguide and the microstrip line at a rate proportional to approximately f3/2. By selecting proper dimensions and dielectric materials, the dielectric slab waveguide can be used to guide THz wave efficiently with high power confinement. These properties may have some potential applications in the THz regime.
Experimental investigation into probability of detection for fatigue cracks in sonic IR imaging

Probability of detection (POD) for defects under given test conditions is an important statistical technique for the detection reliability assessment. In this study, we investigate a set of 45 steel specimens with fatigue cracks in different lengths. Experimental results show that the increase of the crack length will enhance the crack heating response, and the logarithmic relationship between the response signal and the crack length has a better linearity compared to others. Based on experimental data and the statistic characteristics, the linear regression analysis is introduced to estimate the POD function. The study provides a quantitative evaluation for the crack detection reliability in sonic infrared imaging.
Progress of UHF/VHF plasma antenna research

Plasma antenna has characteristics such as low RCS, reconfigurable, etc. But compared with common metal antenna, it has larger size and weight and need extra exciting RF power. In plasma antenna research, the most serious problem is the antenna gain which is difficult to compare with common metal antennas. This article introduces the plasma antenna progress of the Chinese Academy of Science, which has begun this theme since 2004. In our research, we have got good antenna gain and pattern parameters that are very close to metal antennas.
Registration Using Robust Kernel Principal Component for Object-Based Change Detection

Postclassification comparison provides a feasible approach to detect the changes of remote sensing images which have strongly inhomogeneous scenes. For pre- and postevent scenarios, registration is a challenging task because variform classifications may result in a dearth of homologous points to be used as tie points. In this letter, we show how the variform objects can be precisely registered using their robust kernel principal components (RKPCs). The contribution can be divided into two parts. First, a robust kernel principal component analysis (RKPCA) method is proposed to capture the common pattern of the variform objects. Second, a registration approach based on the implicit RKPCs is derived. We demonstrate the power of the proposed approach using two real cases: one for lake monitoring in the Jiayu region, and the other for damage mapping of earthquake-induced barrier lake at Tangjiashan. The results show that the method is effective in capturing structural pattern and generalizes well for registration.
Simplify the method of decision tree: an example for surface modeling

Classification is an important problem in data mining. Given a database of records, each with a class label, a classifier generates a concise and meaningful description for each class that can be used to classify subsequent records. A number of popular classifiers construct decision trees to generate class models. In this paper, the idea of algorithm for building a decision tree is introduced by comparing the algorithm of information gain or entropy. According to the theory of rough sets, the method of constructing decision tree is discussed. The produced process of decision tree is given as an example of surface modeling. Compared with ID3 algorithm, the complexity of decision tree is decreased, the construction of decision tree is optimized the better rule of data mining could be built.
An Aggregation Approach to Short-Term Traffic Flow Prediction

In this paper, an aggregation approach is proposed for traffic flow prediction that is based on the moving average (MA), exponential smoothing (ES), autoregressive MA (ARIMA), and neural network (NN) models. The aggregation approach assembles information from relevant time series. The source time series is the traffic flow volume that is collected 24 h/day over several years. The three relevant time series are a weekly similarity time series, a daily similarity time series, and an hourly time series, which can be directly generated from the source time series. The MA, ES, and ARIMA models are selected to give predictions of the three relevant time series. The predictions that result from the different models are used as the basis of the NN in the aggregation stage. The output of the trained NN serves as the final prediction. To assess the performance of the different models, the naive, ARIMA, nonparametric regression, NN, and data aggregation (DA) models are applied to the prediction of a real vehicle traffic flow, from which data have been collected at a data-collection point that is located on National Highway 107, Guangzhou, Guangdong, China. The outcome suggests that the DA model obtains a more accurate forecast than any individual model alone. The aggregation strategy can offer substantial benefits in terms of improving operational forecasting.
System dynamics modeling and prototype investigation of a new SMA-electric motor hybrid linear actuator

This paper presented a new hybrid linear actuator which has significant potential to achieve both large force and large displacement based on SMA wires and DC motors. There were one screw and two locking nuts used to accumulate the small displacements of SMA wire actuators. And the SMA wires were connected in parallel to enhance the force output. A system dynamic model of this hybrid actuator was made on the present study, which was composed by the constitutive model of the SMAs, the electrical and heat transfer behavior of SMA wires, and dynamics of the linear actuation system. Our study explored the accuracy of the model and illustrated the properties of the hybrid linear actuator prototype. Preliminary tests revealed that this kind of hybrid actuator prototype could output a driving force of at least 50N and a single step displacement of 3.34mm in one step cycle. The multi-steps operation frequency under ambient atmosphere was about 0.05Hz. Both numerical simulation and experimental investigation showed that this hybrid linear actuator could achieve large force and large displacement with high stepping accuracy like a step motor.
A Normalization Method of Delimiting the Electromagnetic Hazard Region of a Wireless Power Transfer System

To avoid the electromagnetic hazard (EMH) that exists in wireless power transfer (WPT) systems and ensure human safety, this paper proposes a normalization method of delimiting the EMH region (EMHR) of WPT systems. The analytic expression of electromagnetic field intensity near a WPT system is deduced and verified. It is determined that the electromagnetic field generated by an electrified coil is related to the coil radius, turns, current and resonance frequency. Based on the study of the electromagnetic field intensity of a reference coil, normalization factors are introduced to evaluate the corresponding value of other coils immediately. According to the international safety guideline, the normalization method of delimiting the EMHR is proposed. First, the EMHR of the reference coil is obtained and simplified as a cylinder. Second, according to the relation of the electromagnetic field between the reference coil and other electrified coils, the EMHR of other electrified coils can be deduced based on normalization factors. Finally, the EMHR of the WPT systems is synthesized by EMHR of the primary and secondary coils. The normalization method is verified with finite element analysis software. It is convenient to delimit the EMHR of the WPT system by using the normalization method.
Detection of nuclei clusters from cervical cancer microscopic imagery using C4.5

cervical cancer is the second most common cancer among women. At the same time, cervical cancer could be largely preventable and curable with regular Pap tests. This test can find nuclei changes in the cervix. Accurate nuclei detection is extremely critical as it is the previous step of analysing nuclei changes and diagnosis afterwards. In recent years, automatic nuclei segmentation has increased dramatically. Although such algorithms could be utilised in the situation for sparse nuclei since they are intuitively detected, the segmentation for the complicated nuclei clusters is still challenging task. This paper presents a new methodology for the detection of cervical nuclei clusters. We first detect all the nuclei from the cervical microscopic image by an ellipse fitting algorithm. All the ellipses are then classified into single ones and cluster ones by C4.5 decision tree with selected features. We evaluated the performance of this method by the classification accuracy, sensitivity, and cluster predictive value. The result shown that the promising classification accuracy (97.8%) is obtained using C4.5 with 9 relative features.
Research on the Inactivation Effect of Low-Temperature Plasma on Candida Albicans

A dielectric barrier discharge was used to generate low-temperature plasma to treat Candida albicans. When the gap spacing was 3 mm, the killing log value (KLV) of the plasma on Candida albicans within 20 s of exposure was more than five, and for 4 and 5 mm gap spacing, the KLV within 25 s was more than five. With the extension of exposure time, the decrease in velocity of the number of living Candida albicans was fastest for the gap spacing of 3 mm, and then for 4 and 5 mm spacing. With 60 s of electric field treatment, as the applied voltage increases, the survival number of Candida albicans has no significant difference from that of the control sample. As for the inactivation mechanism of plasma on Candida albicans on the molecular microbiology side, transmission electron microscopic examination and the results of protein, nucleic acid and K+ detection in the extracellular environment showed that the plasma destroyed the outer structure of Candida albicans. Cytoplasm was also released, which caused Candida albicans to be dead. On the plasma physics side, the role of the electric field during Candida albicans inactivation by plasma is considered negligible. Therefore, charged particles and reactive species in plasma might play a dominant role in the process of destroying the outer structure of Candida albicans.
Modified AUSMPW+ scheme and its application

Presented is an investigation into Advection Upstream Splitting Method (AUSM) family schemes. A newly improved version of the AUSM scheme, called AUSMPW+, was developed to increase the accuracy and computational efficiency of AUSM scheme in capturing oblique shock without compromising robustness. With a new definition of the numerical speed of sound at a cell interface, the ability of capturing an oblique shock is remarkably enhanced. Pressure wiggles near wall and shock overshoots across a strong shock are cured by introducing weighting function f based on pressure. In present research, f function was slightly modified to increase the computational efficiency. Extensive numerical test validate that AUSMPW+ scheme with modified function f provide accurate solution of not only transonic but also supersonic flow. The test cases include: (1) SOD shock tube; (2) RAE 2822 airfoil transonic flow; (3) supersonic missile with highly separated flow; (4) AGARD CT5 unsteady test.
Parallelization and performance optimization of calculation in three-dimensional underwater acoustic propagation on modern many-core processor

Sound wave is the only medium that can propagate effectively over long distances in the ocean. Underwater acoustic data plays an important role in the study of computational ocean acoustics. But the computation in three-dimensional underwater acoustic propagation is time-consuming, which is difficult to meet the real-time demand. In this paper, we put forward parallelization and performance optimization which is combined with the architecture of a new generation of processors from the Intel Xeon Phi family and the computing characteristics of the application to decrease the time of a parabolic equation solver in computational ocean acoustics. The results showed that the speed of computation can be greatly improved by the strategy mentioned in this paper. The method used in this paper is not only general for other similar computing model in computational ocean acoustics but also a guideline of performance enhancement for scientific and engineering application running on modern many-core computing platform.
3D Pose Estimation of Front Vehicle Towards a Better Driver Assistance System

Driver assistance system enhances traffic safety and efficiency. Accurate 3D pose of front vehicle can help driver to make right decisions on road. We propose a novel real-time system to estimate 3D pose of the front vehicle. This system consists of two parallel threads: vehicle rear tracking and mapping. Vehicle rear is firstly identified in the video captured by an on-board camera, after license plate localization and foreground extraction. 3D pose estimation technique is then employed with respect to extracted vehicle rear. Most 3D pose estimation techniques need prior models or a stereo initialization with user cooperation. It is extremely difficult to obtain prior models due to various appearances of vehicle rears. Moreover, it is unsafe to ask for driver's cooperation when vehicle is running. In our system, two initial key frames for stereo algorithm are automatically extracted by vehicle rear detection and tracking. Map points are defined as a collection of point features extracted from vehicle rear with their 3D information. These map points are inferences that relating 2D features detected in following vehicle rears with 3D world. Relative 3D Pose between current vehicle rear and on-board camera is then estimated through mapping that matches map points with current point features. We demonstrate the abilities of our system by augmented reality, which needs accurate and real-time 3D pose estimation.
Monitoring the dynamics of forest area in Anshan based on TM images

Forest area as an important parameter of the forest resources, to obtain forest area timely access is very significant for the monitoring forest resources. Remote sensing technology, because of its characteristics of multi-temporal and large-scale, is widely used on the quick access to the forest information [1-2]. The study area in this paper is Anshan, and we will select the highest accuracy classification from supervised classification, unsupervised classification and object-oriented classification to extract the forest area of Anshan in 1995, 2000 and 2006. The results showed that: the forest area of Anshan in three periods (1995, 2000 and 2006) is: 4588km2, 4668km2 and 4698km2.
Partial H-plane bandpass filters based on substrate integrated folded waveguide (SIFW)

In this paper, two types of partial H-plane bandpass filter are proposed, which are implemented by substrate integrated folded waveguide (SIFW). These filters have advantages of compact, easy for integration, low cost, and mass-producible properties. The presented partial H-plane bandpass filter with H-plane septa has the similar frequency responses as those of traditional E-plane waveguide filter. Another partial H-plane bandpass filter is implemented by inserting H-plane slots in H-plane metal vane. Two filters are designed using the proposed two types of partial H-plane filters. The vertical metal walls of SIFW are realized by closely spaced metallic vias. The tapered line is used as transition between SIFW and microstrip. The two designed partial H-plane filters exhibits excellent performances by simulation.
Comparison analysis on supervised learning based solutions for sports video categorization

Due to the wide viewer-ship and high commercial potentials, recently, sports video analysis attracts extensive research efforts. One of the main tasks in sports video analysis is to identify sports genres i.e. sports video categorization. Most of the existing work focus on mapping content-based features to sports genres by using supervised learning methods. Moreover, video data sets seeks efficient data reduction methods due to the large size and noisy data. It lacks comparison analysis on the implementation and performance of these methods. In this paper, the research is carried out by using four dominant machine learning algorithms, namely Decision Tree, Support Vector Machine, K Nearest Neighbor and Naive Bayesian, and comparing their performance on a high dimensional feature set which selected by some feature selection tools such as Correlation-based Feature Selection (CFS), Principal Components Analysis (PCA) and Relief. Experimental results shows that Support Vector Machine (SVM) and k-NN are not sensitive to reduction of training sets. Moreover, three different feature reduction methods perform very differently with respect to four different tools.
Speaker segmentation using deep speaker vectors for fast speaker change scenarios

A novel speaker segmentation approach based on deep neural network is proposed and investigated. This approach uses deep speaker vectors (d-vectors) to represent speaker characteristics and to find speaker change points. The d-vector is a kind of frame-level speaker discriminative feature, whose discriminative training process corresponds to the goal of discriminating a speaker change point from a single speaker speech segment in a short time window. Following the traditional metric-based segmentation, each analysis window contains two sub-windows and is shifting along the audio stream to detect speaker change points, where the speaker characteristics are represented by the means of deep speaker vectors for all frames in each window. Experimental investigations conducted in fast speaker change scenarios show that the proposed method can detect speaker change points more quickly and more effectively than the commonly used segmentation methods.
An Improved Co-Rotational Algorithm for Nonlinear Aeroelasticity Solution

Computational structural dynamics (CSD) and Computational fluid dynamics (CFD) referring to aeroelasticity are highly nonlinear problems in time domain. Euler equation is solved by finite volume method with dual-time technology to obtain nonlinear unsteady aerodynamic load; the finite element co-rotational theory is applied to model geometric nonlinear structure, and an approximate energy conservation algorithm is developed to achieve nonlinear dynamic response; combined with interface technique, which involves conservation volume transformation and second order time loosely coupled algorithm, an improved CFD/CSD coupled system is designed to solver nonlinear aeroelasticity, Then, the developed algorithm is performed on aeroelastic response of NACA 0012 airfoil, the results illustrate that the improved algorithm has superior accuracy and efficiency compared with conventional method.
An Event-Driven Sports Video Adaptation for the MPEG-21 DIA Framework

We present an event-driven video adaptation system in this paper. Events are detected by audio/video analysis and annotated by the description schemes (DSs) provided by MPEG-7 multimedia description schemes (MDSs). And then, adaptation take account of users' preference of events and network characteristic to adapt video by event selection and frame dropping as following three steps: 1) the event information is parsed from MPEG-7 annotation XML file together with bitstream to generate generic bitstream syntax description (gBSD), 2) users' preference, network characteristic and adaptation QoS (AQoS) are considered for making adaptation decision, 3) adaptation engine automatically parses adaptation decisions and gBSD to achieve adaptation. Different from most existing adaptation work, the system adapts video by interesting events according to users' preference. To achieve a generic adaptation solution, the system is developed following MPEG-7 and MPEG-21 standards. gBSD based adaptation avoids complex video computation. 30 students from various departments test the system with satisfaction. Although, the system is tested on basketball video adaptation so far, it is easy to extend to other video domains
An improved SIR filter designed using LTCC technology

An improved quarter wavelength (lambda/4 ) SIR (stepped impendence resonator) in LTCC (low temperature co-fired ceramic) is proposed. The improved SIR in LTCC can have much smaller resonant length at desired frequency and have much higher 1th spurious resonant frequency comparing to the traditional ones. Filters that are constructed by the improved SIRs can have small size and high spurious pass band. A three order bandpass filter with the improved SIR is designed in LTCC. The filter is simulated in HFSS. Simulation results show that the filter has a very good filter performance while it only covers a very small area and has a wide stop band.
Ultrathin metasurface based on phase discontinuity with maximal cross-polarization efficiency

An ultrathin flat metasurface experimentally realizing bi-functional microwave manipulation has been demonstrated to be able to approach the theoretical limit of cross-polarization (cross-pol) conversion efficiency of the transmission. With the excitation of a localized waveguide mode, an abrupt helicity-dependent phase change is introduced to the transmission and can be engineered by assembling the spatial orientation of each Pancharatnam-Berry phase element. By realizing a constant phase gradient, an anomalous refraction is unanimously demonstrated under circular polarized incident wave. Besides, due to the helicity-dependent phase modification, we also demonstrate an ultra-thin metalens with bi-functionality. By controlling the handedness of the incident wave, converging and diverging functions are interchangeable with the same flat lens. The proposed metalens has only one single layer as thin as 0.001λ, which massively reduces the thickness of the microwave lens along the wave propagation direction. With the great improvements in efficiency and thickness reduction, our design provides a promising approach to miniaturize, planarize and integrate multiple microwave components.
LTCC Vertical Interconnection Modeling by Multi-dimensional Cauchy Approximation

Multidimensional Cauchy approximation is adapted in modeling process to characterize the RF performance of the low temperature co-fired ceramic (LTCC) interconnection structure. The Cauchy approximation function forms a surrogate to express the input and output mapping relation. The parameters of the multi-dimensional Cauchy rational polynomial can be confirmed by solving the convex program problem. A grounded coplanar wave guide (GCPW) vertical interconnection structure model is developed by this method, and the result shows the developed model perform a better predictive performance.