nils-herrmann/clean_scirepeval huggingface dataset:
Convolutional neural networks for posed and spontaneous expression recognition

Differentiating posed expressions from spontaneous ones is a more challenging task than conventional facial expression recognition. There are many methods proposed to differentiate posed and spontaneous expressions based on pixel level information. However, these methods still have some limitations : (1) Most of the studies use the difference between onset (the early stages of an expression) and apex (the most intense stages of an expression) pixel-level raw images as inputs, which may not only contain noisy information, but also lose some useful information. (2) A lot of previous work uses hand-crafted features designed by rules, which suffers from inadequate capability of abstraction and representation. Considering that the high-level image representations usually have less noisy information, we propose a special layer named “comparison layer” for convolutional neural network (CNN) to measure the difference between onset and apex images of high-level representations (instead of pixel-level difference). We add the comparison layer to a group of CNNs, and combine the learned representations from those CNNs to form inputs of a classifier for differentiating posed and spontaneous expressions. Experiments on USTC-NVIE database (so far the largest database for this task) show that our method significantly outperforms the state-of-the-art methods (91.73% to 97.98%).
A mathematical guideline for designing an AC-DC LLC converter with PFC

Although LLC topology has been applied to AC-DC power supplies as a Power Factor Correction (PFC) converter in the literature, there is no publications present intuitive equations that simplify LLC designing in order to meet the PFC gain requirements. In this paper, a mathematical design guideline is derived for LLC PFC converter applications, proving that by carefully designing the resonant tank gain at parallel resonant frequency at the peak AC voltage higher than 1, its gain will meet the PFC requirement for other AC voltages and result in a successful single-stage PFC design with power factor over 0.99. The guideline is extended to offline wide input and output voltage LLC PFC applications. A 240-Watt prototype of a single-stage LLC LED driver with PFC has been built to verify the feasibility of the proposed design guideline.
Adaptive NN Tracking Control of Uncertain Nonlinear Discrete-Time Systems With Nonaffine Dead-Zone Input

In the paper, an adaptive tracking control design is studied for a class of nonlinear discrete-time systems with dead-zone input. The considered systems are of the nonaffine pure-feedback form and the dead-zone input appears nonlinearly in the systems. The contributions of the paper are that: 1) it is for the first time to investigate the control problem for this class of discrete-time systems with dead-zone; 2) there are major difficulties for stabilizing such systems and in order to overcome the difficulties, the systems are transformed into an n-step-ahead predictor but nonaffine function is still existent; and 3) an adaptive compensative term is constructed to compensate for the parameters of the dead-zone. The neural networks are used to approximate the unknown functions in the transformed systems. Based on the Lyapunov theory, it is proven that all the signals in the closed-loop system are semi-globally uniformly ultimately bounded and the tracking error converges to a small neighborhood of zero. Two simulation examples are provided to verify the effectiveness of the control approach in the paper.
A Process Modeling-Based Approach for Web Service Management

Quality of individual services is substantial to guarantee high performance and availability of overall composite service oriented systems. This requires the process of diagnosing service quality degradation and responding to it in a timely and non-stopping manner. This paper presents a modeling-based approach to coordinate the process of Web service management, configuring parameters or invoking other tasks. This approach uses executable process models to represent diagnosis logic and orchestrate the replacement. The process models can interact with the system and accept administrators' instruction at the process level. As a result, a service can be automatically replaced by the best available strategy without any downtime of the overall system. Our approach is implemented on an architecture of Enterprise Service Bus (ESB) that allows intercepting services and redirecting messages with little performance penalty. The experiment demonstrates the efficiency of this approach using a loan-brokering Web service on ESB.
Common Capacitor Multiphase LLC Converter With Passive Current Sharing Ability

In high-power applications, parallel operation is required to improve both efficiency and reliability. In an LLC converter, it is difficult to achieve parallel operation due to the gain sensitivity to component tolerance. This paper proposes a new structure of a common resonant capacitor for a multiphase LLC converter, which can achieve very good current-sharing performance with no additional components or control. To evaluate the current-sharing performance, a new first harmonic approximation (FHA) model is built in this paper to analyze the LLC converter with coupled resonant tanks. Both FHA analysis and powersim (PSIM) simulation results demonstrate the load-sharing improvement of the proposed common capacitor LLC resonant converter over the conventional two-phase LLC converter. The current-sharing performance from the FHA analysis and the PSIM simulation are compared, and the error of the FHA analysis is evaluated and explained. A 600 W two-phase LLC converter prototype based on the proposed method is also built to verify the feasibility. Excellent current-sharing performance (6% resonant current sharing error at a wide load range) has been achieved.
A Design Method for PI-like Fuzzy Logic Controllers for DC–DC Converter

This paper proposes a novel design procedure of proportional and integral (Pl)-like fuzzy logic controller (FLC) for DC-DC converters that integrates linear control techniques with fuzzy logic. The design procedure allows the small signal model of the converter and linear control design techniques to be used in the initial stages of FLC design. This simplifies the small signal design and the stability assessment of the FLC. By exploiting the fuzzy logic structure of the controller, heuristic knowledge is incorporated in the design, which results in a nonlinear controller with improved performance over linear PI controllers.
Development of an energy harvesting backpack and performance evaluation

A biomechanical energy harvesting backpack that generates electrical energy during human walking is presented. This device differs from previous designs because it integrates motion from both lower limbs into a single mechanical drive train. The energy harvesting backpack produced an average of 15 W of electricity during walking at a speed of 1.2m/s. It was found that approximately one quarter of the total mechanical work harvested was from the negative work performed during walking. This technology could potentially be used to power portable biomedical devices.
A Practical Solution for the Current and Voltage Fluctuation in Power Systems

This paper presents an innovative formulation and implementation for the steepest descent method to minimize the current and voltage fluctuation in power systems. The steepest decent is selected because of its mathematical simplicity. Its main disadvantage is circumvented by proposing a technique that selects proper initial values in order to guarantee its convergence. This technique depends on the Yule-Walker equation. The suggested technique for disturbance extraction is utilized to operate a power conditioner in order to mitigate the current fluctuation, and its performance is compared with the output of the vector control that is commonly used for the mitigation of the current and voltage fluctuation. The presented ideas are conveyed and approved through simulation results using Malab/Simulink. Moreover, some experimental results are provided to affirm the practicality of the presented concepts.
A common inductor multi-phase LLC resonant converter

In this paper, a new common inductor current sharing method is proposed for multi-phase LLC resonant converter for high power application. Automatic current sharing is achieved by using a common resonant inductor for all the LLC resonant stages, by connecting the resonant inductors in each phase in parallel. The proposed method can automatically share the load current without any additional circuit and control strategy. The current share performance of the proposed common inductor current share method is analyzed under Fundamental Harmonic Analysis (FHA) assumption. A 600W two-phase LLC converter prototype based on the proposed method is built to verify the feasibility. Excellent current sharing performance (less than 0.5% current sharing error at full load) has been achieved.
An LLC Converter Family With Auxiliary Switch for Hold-Up Mode Operation

This paper proposed a new half-bridge (HB) LLC resonant converter family with pulse-width modulated (PWM) auxiliary switch (sLLC converter) for hold-up mode operation. The proposed sLLC converters could operate with synchronous rectifier, which is suitable for low-output voltage applications. In the proposed converters, an auxiliary switch is added at the primary side to provide charging path for the series resonant inductor. For nominal 400-V input, sLLC achieves same performance as conventional LLC converter, and all the good features such as soft switching are naturally retained. For slight input voltage fluctuation, frequency modulation is used to regulate the output voltage. When the input voltage reduces further, HB switches will operate at constant minimum frequency, and the auxiliary switch will operate in the PWM mode to energize the resonant inductor with the bus voltage directly during hold-up period. Thus, the converter achieves higher voltage gain, and the output voltage can be maintained at desired level. To verify the effectiveness of the proposed sLLC converter, operational principle and equivalent circuits will be carefully explained and analyzed in this paper. A 300-W prototype is built for 250–400-V input 12-V output application.
Digital charge balance controller with low gate count to improve the transient response of buck converters

A linear/non-linear digital controller is presented which allows a Buck converter to recover from a load transient event with near-optimal voltage deviation and recovery time. It is demonstrated that near-optimal transient performance can be obtained without information pertaining to the Buck converter's output inductor. The proposed controller can also be extended to applications which require load-line regulation. Unlike previous digital time-optimal controllers, the proposed controller does not require digital multiplier or divider blocks nor does it require two-dimensional look-up tables. Thus, the controller can be implemented with a significantly low gate count allowing for the use of low-cost FPGAs or CPLDs. Furthermore, the proposed controller provides an excellent transient response as it is capable of reacting asynchronously to a load transient event.
A method of structure optimization for high-speed and heavy-load robot based on dynamic characteristic analysis

In this paper, a method of structure optimization for high-speed and heavy-load robot based on dynamic characteristic analysis is presented. Firstly, the flexible coupling dynamics model of the robot is established and modal analysis is carried out. Then the concept of relative sensitivity is presented, by which the optimization variables are determined. According to the operating characteristics of the robot, such as palletizing cycles per hour, terminal repeat positioning accuracy and rated load, the optimization indicators can be proposed, which are the lowest natural frequency, the maximum acceleration and static stiffness, speed integrated characteristics. Combined with work space constraint, a multi-objective optimization model is established, which is solved by NSGA-II genetic algorithm. Finally the optimized results are analyzed and compared, which can prove the validity of the method.
A CBIR framework: Dimension reduction by radial basis function

In classical content-based image retrieval (CBIR) system, using Euclidean metric, it usually can not achieve good results, because of the semantic gap. To solve the difficulty problem, present a relevance feedback(RF) paradigm which is naturally guided only on dimension reduction with radial basis function(RBF). While images are often represented by feature vectors, the distance is usually different from the distance induced by the space. The geodesic distances on manifold are employed to measure the similarities between images. According to man interactions(loops) in a RF driven query-by-example system, the inhere similarities between images can be exactly estimated. We design a algorithm framework, in order to approximate the optimal mapping function with a RBF neural network(NN). The semantic gap (SG) of a new visual image can be inferred by the RBF neural network. Experiment results show that our method is effective in improving the performance of visual retrieval.
A Schema-Guiding Evolutionary Algorithm for 0-1 Knapsack Problem

A Schema-Guiding Evolutionary Algorithm (SGEA) is proposed in this paper. The novel SGEA has many good features. It proposes the schema-modified operator to adjust the distribution of the population. What's more, it constructs an elite-schema space and proposes the cluster-center schema to guide the direction of individual's evolution. And by such two strategies, the diversity of the population and the local and global search power can be greatly improved. The experimental results show that the SGEA proposed in this paper has many better performances, compared with other methods such as simple genetic algorithm, greedy algorithm and so forth.
Absorption Enhancement for Black Phosphorus Active Layer Based on Plasmonic Nanocavity

In this letter, we propose a strategy to enhance absorption in the black phosphorus absorber based on a nanocavity structure. By introducing a porous silver layer, an enhanced broadband light absorption can be obtained in the spectral range of 520–820 nm. The optical characteristics of the black phosphorus absorptive layer are thoroughly analyzed by absorption spectra, electric intensity distribution, and power flow distribution. Numerical and analytical analysis revealed that the optical absorption of the black phosphorus layer with a porous silver layer can be enhanced by 50% and 396% at the resonant wavelength of 690 nm for p-polarized and s-polarized incidences, respectively, when compared to that without a silver layer. Furthermore, the short-circuit current density (<inline-formula><tex-math notation="LaTeX">$J_{{\rm{SC}}}$</tex-math></inline-formula>) was calculated for the proposed architecture. The peak value of <inline-formula><tex-math notation="LaTeX">$J_{{\rm{SC}}}$</tex-math> </inline-formula> was more than 18 mA/cm<sup>2</sup>. It is demonstrated that this super absorption structure could find important applications on plasmonic-assisted photovoltaic devices or other opto-electronic devices, which will promote the development of ultrathin on-chip energy harvesting and new thin-film active devices.
An improved design approach for high order switched-capacitor band-pass filters

This paper proposes an improved design approach for high order switched-capacitor (SC) band-pass filters. The de-normalized LC filter prototype is obtained directly using the proposed approach. The signal flow graph (SFG) of the LC prototype is obtained using active ladder synthesis method. A new node scaling method for simplifying the signal flow graph of the filters is proposed. With the node scaling, the dynamic range of the filter is increased, and the frequency response of the filter becomes more precise. A 10th order all poles switched-capacitor band-pass filter is designed using the proposed approach. The simulated results prove the advantages of the proposed node scaling method.
A Simplified Model for Resistive Switching of Oxide-Based Resistive Random Access Memory Devices

A physical-based simplified model is presented to quantify the resistive switching behavior of oxide-based resistive random access memory (RRAM). In this model, the analytical expressions of the RESET time of RRAM devices and the correlated resistance in high-resistance states are presented and experimentally verified. Based on the extracted physical-based model parameters from measured data, the resistive switching characteristics of oxide-based RRAM devices can be evaluated.
Adaptive Neural Network-Based Tracking Control for Full-State Constrained Wheeled Mobile Robotic System

In this paper, an adaptive neural network (NN)-based tracking control algorithm is proposed for the wheeled mobile robotic (WMR) system with full state constraints. It is the first time to design an adaptive NN-based control algorithm for the dynamic WMR system with full state constraints. The constraints come from the limitations of the wheels’ forward speed and steering angular velocity, which depends on the motors’ driving performance. By employing adaptive NNs and a barrier Lyapunov function with error variables, then, the unknown functions in the systems are estimated, and the constraints are not violated. Based on the assumptions and lemmas given in this paper and the references, while the design and the system parameters chose properly, our proposed scheme can guarantee the uniform ultimate boundedness for all signals in the WMR system, and the tracking error converge to a bounded compact set to zero. The numerical experiment of a WMR system is presented to illustrate the good performance of the proposed control algorithm.
Adaptive receiver for multirate CDMA systems on Kalman criterion

In frequency-selective fading channel, the main difficulty to use the adaptive receiver is that the adaptation should resume after the rate change. As a result, the performance will be degraded due to the transient. In the proposed receiver, the main structural is Rake receiver; there is an adaptive filter of multiple parallel structural in each channel. Then, the adaptation of the weight vector for each rate is possible during the period of different rates.
Application of FY-2C Data in Rainstorm Nowcasting

The stationary meteorology satellite data are useful for rainstorm forecasting, the cloud top temperature of FY-2C IR1 channel are used in this research. Based on the deviation analysis and projection correction, it is found that selected 5 x 5 pixels are enough for the accuracy of rainstorm forecasting. The exactly matches between the changes of time series of TBB and the evolution of convective clouds are available. When the unstable energy is gathered, the cloud system obviously turns to the pattern. The phase-space structure method extracts the transition information for the rainstorm forecasting. The research results show that this method is effective for forecasting of strong convection, it is not only to improve the use of satellite data efficiently, but could improve the capability of accurate forecasting of mid-latitude rainstorms in China.
A 30-MHz isolated push-pull VHF resonant converter

A new isolated push-pull very high frequency (VHF) resonant DC-DC converter is proposed. The primary side of the converter is a push-pull topology derived from the Class EF2 inverter. The secondary side is a class E based low dv/dt full-wave rectifier. A two-channel multi-stage resonant gate driver is applied to provide two complementary drive signals. The advantages of the converter are as follows: 1) the power isolation is achieved; 2) the MOSFETs and diodes are under soft-switching condition for high efficiency; 3) the voltage stress of the MOSFET is much reduced; 4) the parasitic inductance and capacitance can be absorbed. A 30~36 VDC input, 50-W/ 24-VDC output, 30-MHz prototype has been built to verify the functionality.
A Novel Two Phase Nonisolated Full Bridge With Shared Primary Switches

In this paper, a new full bridge topology called the two-phase nonisolated full bridge (NFB) is introduced. The proposed two-phase NFB can handle the same power as two parallel NFB converters, but with less MOSFETs, better efficiency, and lower cost. To demonstrate the advantages of the new topology, two prototypes are built on a 12-layer 2-oz PCB board, one with four inductors, the other with three inductors. Two prototypes achieve 82.3% and 82% efficiency at 1-MHz full load (1 V/80 A), respectively. This is compared to 81.8% efficiency of the two paralleled NFB converters. At light load (1 V/10 A), a 4% efficiency improvement is achieved. Experimental results demonstrate that compared with two paralleled NFB converters, the two-phase NFB converter is able to achieve better efficiency with a simplified power train circuit and reduced cost.
A Novel Operation Scheme for Oxide-Based Resistive-Switching Memory Devices to Achieve Controlled Switching Behaviors

A new operation scheme on oxide-based resistive-switching devices [resistive random access memory (RRAM)] is proposed to improve the controllability of switching processes in order to achieve an improved memory performance. The improved device-to-device and cycle-to-cycle uniformity, reduced RESET current, and adjustable RHRS/RLRS ratio are demonstrated in the HfOx-based RRAM devices by using the new operation scheme, indicating the validity of the new operation scheme. The physical mechanism accounting for the new operation scheme effect is discussed.
A New Duty Cycle Control Strategy for Power Factor Correction and FPGA Implementation

The bottleneck of digital control for power factor correction (PFC) implementations is mainly due to three aspects: high calculation requirements, high cost, and limited switching frequency compared with analog implementations. A new duty cycle control strategy for boost PFC implementations is proposed in this paper. The duty cycle is determined based on the input voltage, reference output voltage, inductor current, and reference current. The duty cycle determination algorithm includes two terms, the current term and the voltage term, which can be calculated in parallel and requires only one multiplication and three additions (subtractions) operations in digital implementation. A 400-kHz switching frequency boost PFC based on field programmable gate array implementation and its test results show that the proposed new duty cycle control strategy has great potential in the next generation of high switching frequency PFC implementations, due to its lower calculation requirement, lower cost, and better performance than the conventional PFC control methods
An efficient communication protocol for single- and multi-module isolated digital power supplies using a single pulse-transformer

In this paper, an 8B/10B-based protocol is developed to optimize communications for single- and multi-module isolated digital power supplies. The protocol allows multiplexed feedback communications which transmits the feedback data of multiple power stages using a single pulse-transformer, which saves substantial cost of high-speed isolators. The protocol consumes less bandwidth than existing protocols. Experimental results of a prototype demonstrate the feasibility of the proposed system.