nils-herrmann/clean_scirepeval huggingface dataset:
Recognition of contact interface defect in metal plate based on pulsed phase thermography

Defect recognition is an important aspect to improve the efficiency of testing, reduce the manual workloads and the subjectivity of people's judgments in Ultrasonic infrared thermography (UIRT). Aiming at the problem of low efficiency and poor ability on the contact interface defect recognition, the pulsed phase thermography (PPT) is studied in this paper. In the pulsed phase method (PPM), on the one hand, the temperature signals are transformed from time domain into frequency domain. On the other hand, the phase information, for example the phase image sequence, is obtained to judge different type of defect heating generation according to the thermal diffusion ability of different materials. Research results show that the surface defect and deep-seated defect can be judged from the phase image sequence, and the different thermal diffusions can be used to distinguish the crack from paint spots. This research aims to improve the veracity and validity of defect recognition for UIRT, and lay a theory foundation for the subsequent research.
220GHz band-pass filter based on circular resonance cavities with low loss

In this letter, characteristics of the circular resonant cavity are investigated. A waveguide band-pass filter based on four circular resonant cavities is designed through theories of filters with Chebyshev response and fabricated using sophisticated machining. The effect on the loss within pass-band from the gap in the assembling process is analyzed. The measured results is in good agreement with the simulated ones, in which the center frequency is at 219GHz, the 3dB bandwidth is about 9.75GHz and the minimum loss within pass-band is
Graphene resonant channel transistor

Two kinds of doubly clamped beam graphene resonant channel transistors (RCTs) with local gate configurations, fabricated by direct exfoliation and transfer are presented in this paper. The RCTs are actuated and detected directly by using a vector network analyzer. And the measurement results show that the exfoliation RCT and transfer RCT have resonant frequencies of ~34MHz at 77K and ~88MHz at 300K, respectively. The operation principle of radio frequency (RF) RCT is detailed in this paper. And a compact electrical equivalent circuit model has been given out based on the analysis of electromechanical model of doubly clamped beam and field effect transistor theory. The results show that excellent agreements have been achieved between the experimental results and the simulation results. With the proposed compact model, the RCTs can be useful for developing high sensitivity sensor, or in the perspective of high quality RF filters by using graphene nano-electromechanical systems(NEMS).
Crop yield variation trend and distribution pattern in recent ten years

In recent ten years, a perception exists that the agricultural management and crop cultivars have been improved obviously. But the crop yield variation trend due to above reason remain unknown yet. To evaluate the main food crop (maize, soybean and rice) yield trend from 2007 to 2016, the MODIS product (MCD12Q2) was used to extract the mature date of different crops. A two-band variant of the enhanced vegetation index at mature date was applied to establish empirical yield estimation model, coupling with statistical crop yield data. The validation show the estimated yield had accuracy of 90.9%, 91.7% and 83.3%, respectively. The average maize and soybean yield in study area presented increasing trend, but rice yield presented declining. However, maize yield in 22 cities and soybean yield in 19 cities show decreasing trend actually. Through statistical analysis, the crop yield distribution pattern was proved to be almost fixed. Most cities occupies approximate position on the ranking of relevant crop yield. It was demonstrated that some cities, for example Chifeng city, was suitable to develop specific agriculture economy. This paper can be used to give suggestion for agriculture planning and management.
A 3/5 GHz reconfigurable CMOS low-noise amplifier integrated with a four-terminal phase-change RF switch

This paper presents the first reported in-situ reconfiguration of a narrowband CMOS low noise amplifier (LNA) over two widely separated frequency bands using a GeTe phase-change (PC) switch. Previous work has demonstrated the attractiveness of CMOS-PC integration to realize high-performance reconfigurable RF front-end circuits [1-2]. Four-terminal PC switches with small form factor have been recently shown to possess close-to-ideal properties of an RF switch: a high OFF/ON resistance ratio and extremely high figure-of-merit for RF switches (FCO = 1/(2πRONCOFF)) [3-4]. In this work, we present a robust realization of a reconfigurable 3/5 GHz LNA designed and fabricated in a 0.13 μm CMOS process and flip-chip integrated with a four-terminal PC switch fabricated using an in-house process.
Predicting the adaptability of sudden oak death in China using spatial information technology

Sudden oak death which is caused by the pathogen phytophthora ramorum has killed thousands of oak trees in Europe and North America in recent decades and also threaten the forests in China. In this study, we choose 4 climate predictor variables to predict the adaptability of sudden oak death in China. First we assign the importance of each variable by using analytic hierarchy process(AHP), and then we build the membership function of each variable by using fuzzy mathematics method. With the climate data of 752 weather stations in China, we interpolate them in GIS to generate the variable layers and compute the final adaptability of sudden oak death by averaging the adaptability in each month of the pathogen's general reproductive season. The result shows that sudden oak death can be suitable for a wide range in China, most of where are southeastern regions.
Research on urban heat island effect during Beijing urbanization process by remote sensing and its impact on environmental health

The urban heat island (UHI) effect is becoming an influential factor on the city's environment along with the rapid development of urbanization process. This paper uses Landsat-5 TM RS image of the year 1988, 2007 and 2010 based on NDVITEM model and land temperature retrieval method to obtain Beijing land surface temperature distribution map through digital image processing and land surface temperature (LST) retrieval calculating using thermal infrared (TIR) remotely sensed satellite observation. The analysis showcases that urban heat island effect in Beijing has been dramatically intensified since 1988. Especially in recent years, the urban heat island effect has become increasingly apparent and seriously affected human's health in the way of changing temperature, barometric pressure, humidity, wind as well as air.
A novel self-interference cancellation scheme for full duplex with differential spatial modulation

In this paper, a novel self-interference (SI) cancellation scheme operated in the digital domain is proposed for the full duplex (FD) system configured with two antennas. The basic idea of our scheme is to transfer the strong SI to the inter-symbol interference (ISI), which is easier to cope with, through a combination of the signals received in successive time slots based on the assumptions that the SI channel is reciprocal and the previous transmitted data can be stored. However, this transfer may result in an un-removable error floor when the transmit antenna remains the same during the time slots in the SI cancellation. To solve this problem, we propose to apply differential spatial modulation, which forces two antennas to take turns to transmit signals in every two consecutive time slots. To further compensate for the loss of spatial degrees of freedom owing to the transfer, we propose to involve more time slots in the SI cancellation and allow the transmit antenna to be selected randomly by spatial modulation starting from the third time slot. Simulations on the bit error rate (BER) are conducted, whose results show that the performance of the proposed scheme is improved as more time slots are involved in the SI cancellation, and the proposed scheme with four time slots outperforms the conventional FD system with 3 dB interference-to-noise ratio (INR) for QPSK modulation.
Tighter Performance Bounds on Image Registration

Image registration is a fundamental and important task in image processing. It essentially estimates a transformation that aligns two images. Cramer Rao lower bound has recently been used to establish the performance limit of image registration algorithms. However, it is known to be a weak lower bound for some problems. In this paper, we analyze the mean square error performance of transformation estimation in image registration problems. We focus on rigid body transformations, and derive a set of tighter alternatives, namely the Bhattacharya bound and the Ziv-Zakai bound. Experimental results demonstrate the validity of our performance bounds
Discussion on the influences of townsend ionization coefficient α and secondary electron emission coefficient γ on the characteristics of DBD

Dielectric barrier discharge (DBD) has drawn great attentions in recent years, and the discharge physic is one of the research focuses. In this paper, both Townsend ionization coefficient α and secondary electron emission coefficient γ (SEEC) in DBD are discussed. The value and partial derivative of α in pure helium are compared with that of argon theoretically, which is related to the breakdown voltage and discharge channel radius. The changes of discharge channel radius under different electrical field is obtained, and the high nonlinear relationship between α and electrical field (∂(α)/∂(E)) is believed to be the main reason for discharge contraction. Therefore, we mix a little NH3 in argon to make the α different from that of pure argon and work in the region where the ∂(α/∂(E) is relatively low. In this way, the uniform discharge, similar with He-DBD, can be obtained in the Ar/NH3 DBD.The SEEC y of dielectric is another important parameter in gas discharge. Different types of Townsend discharge is achieved, the value range of y in various dielectrics is estimated based on y(eαd-1) ≈1. The y in He-DBD and N2-DBD is studied and compared to clarify the gas species' effects on y as well. The electron trap feature of dielectric surface and gas species energy are used to explain the changes of y. Moreover, the cathode falling thickness of different dielectric surface is measured according to the luminous structure when DBD is in glow-like discharge region, which may be affected by γ.
Research on Materialized Views Technology in Data Warehouse

With the needs of decision-support information of enterprise and the fast development of computer technologies data warehouse technology come out. The data warehouse is a repository of information collected from multiple, possibly heterogeneous, autonomous, distributed databases. The information stored at the data warehouse is in form of views referred to as materialized views. The design of data warehouse is one of the core research problems in studying and evolution of data warehouse. One of the most important decisions in design of data warehouse is the data warehouse selection. Selecting views to materialize impacts on the efficiency as well as the total cost of establishing and running a data warehouse. So, we develop algorithms to select a set of views to materialize in data warehouse in order to minimize the total view maintenance cost under the constraint of a given query response time. We call it query cost view selection problem (QC_VSP). In this paper, First, we propose query cost view selection problem model. Second, we give three algorithms for QC_VSP; we give view_node_matrix in order to solve it. Third, experiment simulation is adopted. The results show that our algorithm works better in practical cases. We implemented our algorithms and a performance study of the algorithms shows that the proposed algorithm delivers an optimal solution. Finally, we discuss the observed behavior of the algorithms. We also identify some important issues for future investigations.
Integrated optimization of aerodynamic shape with trajectory for aircaft in conceptual design

This paper illustrates aircraft aerodynamic shape design problem by take into account the disciplines of aerodynamics and trajectory. It can be formulated as a multidisciplinary design optimization (MDO) problem. An air-air cruise missile design was considered for studies. Throughout optimization process, aerodynamic analysis and design was performed via Missile Datcom software, all of the flight performance data could obtain by running a three-degree-of-freedom trajectory simulation, iSIGHT software was used to organize aerodynamic with trajectory modules and execute optimization, and the optimal solution could capture using genetic algorithm. Design of Experiment (DOE) method was used to analysis design variables to reduce time of computation. The optimal shape and trajectory parameters of air-air cruise missile could acquire through optimization process. Simulation results demonstrate that the missile performance can be effectively improved based on the application of MDO method.
A new millimeter-wave waveguide-based four-way power dividing/combining network

A novel Ka-band (29-37 GHz) four-way power dividing/combining network, based on Y-Structure waveguide has been proposed. To widen the bandwidth of the dividing/combining network, a stepped-impedance transformer at both E-plane and H-plane is used. One vertical resistive card and two horizontal resistive cards are inserted to improve isolation. The EM simulation shows that, nearly 25% effective bandwidth (ranging from 29 to 37 GHz) is achieved, the return loss is better than -17 dB over the range 29.5-35.5 GHz, and the isolation and output port reflection are better than -11 dB over the whole range. This structure has properties of not only a wide bandwidth, good isolation, low insertion loss and high power capacity, but also a small size, perfect output amplitude and phase balance, and efficient thermal sinking performance, and has potential for millimeter-wave broadband high power combination applications.
Comparison of adaptation methods for GMM-SVM based speech emotion recognition

The required length of the utterance is one of the key factors affecting the performance of automatic emotion recognition. To gain the accuracy rate of emotion distinction, adaptation algorithms that can be manipulated on short utterances are highly essential. Regarding this, this paper compares two classical model adaptation methods, maximum a posteriori (MAP) and maximum likelihood linear regression (MLLR), in GMM-SVM based emotion recognition, and tries to find which method can perform better on different length of the enrollment of the utterances. Experiment results show that MLLR adaptation performs better for very short enrollment utterances (with the length shorter than 2s) while MAP adaptation is more effective for longer utterances.
Optimal decision making for Cooperative Localization of MAUVs

Cooperative Localization(CL) is a crucial cycle in navigation with Multiple Autonomous Underwater Vehicles(MAUVs). Due to the terrible underwater environment, measuring and communicating each other are still difficult challenges for AUVs until now, which both are also essential for CL to improve the position performance. Based on the two principles below: 1)minimizing the consumption of CL without loss of performance; 2)simplifying the communication topology, meanwhile, satisfying the communication requirements, we propose Optimal Decision Making(ODM) for MAUVs under multiple optional measurements and communication topologies. Then, considering two common cooperative manners: homogeneous MAUVs, heterogeneous MAUVs, ODM is presented in detail to examine two tradeoffs, not only between performance and consumption, but also between group performance and single accuracy. Finally, simulation results are provided to illustrate the superiority and practicality of the proposed decision strategy.
Using autonomous agents to make recommendation in a modeling market

Recommender systems provide the user with the items that they might wish to purchase. Most current recommendation systems are too dependent on the users. The users are often required to rate different items and even give comments on the products they purchased. Worst of all, when the user's preferences are changed, the whole recommender systems are usually not adaptive to the new condition. In this paper, an intelligent recommender system architecture is proposed. In this architecture, an autonomous agent is used to track the user's Web browsing behaviours and attempt to anticipate the user's current interests to build up the user profile in a dynamic way. On the other hand, an explicit item model has been applied to each item and item-to-item correlations have been used to assist the agent to give better recommendations.
Ziv–Zakai Bounds on Image Registration

Image registration is a fundamental and important task in image processing. The goal essentially is to estimate the transformation that aligns two images. We focus on the general rigid body transformation case. In this paper, we derive the Ziv-Zakai bounds (ZZB) on image registration by assuming an uncertainty model for the rotation and translation errors, and propose to use the ZZB as a benchmark to evaluate the registration ability of an image pair. We also compare the performance of several image registration algorithms with the derived bounds when applied to several datasets.
Recognition Algorithm for Prostate Calculus Based on Transition Region and PCA-SVM

Recognition of prostate calculus is an important step to determine the source of pathological organ, and is of great importance for further diagnosis of prostate cancer. In this paper, due to some tissues are similar to calculus, and prostate calculus usually adheres to other tissues, a recognition algorithm for prostate calculus based on transition region and PCA-SVM is proposed. Firstly, local entropy, Otsu method and morphology are used to extract transition region. Then suspicious calculus regions are segmented from each independent transition region. Finally, taking domain knowledge and texture features of each suspicious calculus into account, a PCA-SVM model is implemented for the automatic prostate calculus recognition. Our experiment result shows that the proposed algorithm for prostate calculus segmentation and recognition has a satisfactory robustness and accuracy.
Research on Automatic Speaker Recognition Based on Speech Clustering

A novel approach of extracting speaker features based on speech clustering technology which employs both speaker's personality and speech cues is proposed in this work for speaker recognition. Specifically, the speech clustering-based approach is first applied before speaker feature extraction and multi-feature which is extracted respectively from the distinct clusters based on speech clustering is combined as a speaker multi-feature. Those two information cues including speaker's personality and speech are then effectively integrated using the multi-feature for achieving more robust results. The experiments show that using the template matching method the recognition rate with the multi-feature achieve 95.83%, which is 6.48% increase than the recognition accuracy with the long-term average feature. Moreover the average of false acceptance with the multi-feature decreased than the other ordinary features
Detuned Magnetic Dipoles Induced Transparency in Microstrip Line for Sensing

Detuned magnetic dipoles analog electromagnetically induced transparency (EIT) effect in a microstrip transmission line is theoretically and experimentally investigated. Only a single unit cell consisting of two detuned split ring resonators (SRRs) placed on the microstrip line is sufficient for inducing the classical EIT-like effect, which is verified by numerical simulation and experimental measurement. The excited principle and resonance nature of the EIT-like effect in the microstrip line are well elucidated by theory and simulation. It was found that the significant suppression of induced currents in SRR resonators played a key role and resulted in the classical EIT-like effect. The influences of the coupling between SRRs and the detuning of sizes for SRRs on the resonant frequency, the peak magnitude, and the line width of the transparency window are numerically and experimentally analyzed. In addition, it is numerically and experimentally demonstrated that the EIT-like structure based on microstrip line couplings can be employed as a sensor based on refractive index variations and yields a sensitivity of 14.2 mm/RIU and a figure of merit (FOM) of 6.17, which allows our design to offer an excellent potential for high resolution of sensing situations.
Optimization of Forming Process Parameters for Transmission Belt Based on Response Surface Method

The elastic component transmission belt was taken as research object, and forming process parameters was optimized based on response surface method and DYNAFORM. The method of central composite design was used to select process parameters of numerical simulation, the response value of forming height for transmission belt was obtained by numerical simulation, and the second-order response surface model was established to reflect the relationship between process parameters and forming height by the least square method. Process parameters of die clearance, bending angle and stamping speed are taken as design variables, forming height was taken as optimization objective, and Design Expert v8.0.5 was applied to optimize the second-order response surface model. The best combination of process parameters is acquired that bending angle is 150°, die clearance is 1.02t, stamping speed is 3004 mm⋅s-1 and the response value of forming height is 5.69 mm. Progressive die is used to verify response value, the experimental value is 5.61 mm, and the relative error between experimental value and response value is 1.43%. The relative error proves the accuracy of the response surface method applied in the optimization of forming process parameters of transmission belt.
An Electrothermal Model for Empirical Large- Signal Modeling of AlGaN/GaN HEMTs Including Self-Heating and Ambient Temperature Effects

Accurate modeling of electrothermal effects of GaN electronic devices is critical for reliability design and assessment. In this paper, an electrothermal model for large signal equivalent circuit modeling of AlGaN/GaN HEMTs including self-heating and ambient temperature effects is presented. To accurately describe the effect of ambient temperature, two separate electrothermal networks (Idiss, Rdiss, and Cdiss for self-heating, and Iamb, Ramb, and Camb for ambient temperature effect) are used to describe drain-source current slump due to self-heating and ambient temperature effects, respectively. A temperature-dependent thermal resistance and thermal capacitance model is proposed and implemented in the electrothermal network. The extraction of the thermal parameters is fulfilled by using numerical finite-element method. Single tone on wafer load-pull measurements at two operating frequencies (3 and 14 GHz) are carried out for verification purposes. The results show that good agreements on fundamental output power, the second and third harmonics output power, and power added efficiency have been achieved between simulations and measurements over a wide range of -55 °C to 175 °C.