nils-herrmann/clean_scirepeval huggingface dataset:
A Modified Approach on MMSE MIMO Interference Cancellation Detection of Free Space Optical Communication

In this paper, an novel MMSE MIMO detector is proposed with respect to MMSE MIMO channel estimation on free space optical communications(FSO). We will show how a two-step MMSE MIMO estimator can be used to facilitate packet detection as well as to provide superior bit error rate performance. This proposed detector takes channel estimation errors into account by the statistical characteristics of MMSE MIMO channel estimation. When compared with existing soft-output MMSE MIMO detector, simulation results show that the proposed novel detector can remarkably reduce the residual error floor due to the channel estimation errors, while achieving significant performance gain at the cost of negligible increase of complexity. We will show how this approach significantly improves packet detection and how the overall solution approaches the performance of the classical MMSE estimator. The simulation results shows that MMSE MIMO detector based on FSO can reduce the atmospheric scintillation turbulence effects on bit error rate of atmospheric. When the number of transmit antennas is fixed, the bit error rate will decrease with the increasing number of receiving antenna; when the number of transmit antennas is not fixed, as the number of tranmit antennas increases, the channel capacity will increase
Effects of Granulated Red Mud on Lead-Zinc Waste Soil Remediation and Leeks Growth

Effects of granulated red mud addition on the fractionation of Pb and Zn in soil and plants growth were studied by 2 batches of soil column incubation experiment(with and without leeks). Experimental results showed that all treatments with granulated red mud addition significantly decreased the concentrations of bio-available and Zn. Compared with the control, the treatment with5% granulated red mud addition significantly decreased the concentrations of bio-available Pb and Zn after 5, 10and 20 days incubation (26.47%, 40.36% and 40.03%decrease,22.63%,26.62% and 26.55% decrease, for Pb and Zn, respectively). In the combined remediation of Pb and Zn contaminated soil and the effects on growth of leeks, the optimal concentration of granulated red mud addition was 1%, thereby reducing the bio-available fraction of Pb and Zn by24.81 % and 15.9 % respectively during remediation time. The results highlighted the potential of granulated red mud amendments to reduce Pb and Zn bio-available in acid contaminated soil in south of China.
A lithography independent gate definition technology for fabricating sub-100 nm devices

In this paper, a lithography independent gate definition technology to fabricate sub-100 nm device is proposed and experimentally demonstrated. In the proposed technology, the device gate is formed by a spacer over a step next to the gate region. The gate height is thus determined by the step height and the channel is defined by the spacer width. Thus, the channel length is defined by the polysilicon layer thickness, which can be precisely controlled. Experimental results reveal that the resulting gate length is about 75-85% of the deposited film thickness. SEM photographs show that sub-50 nm lines can be formed using this method. Transistors fabricated using the new method have been characterized and excellent I-V characteristics are demonstrated.
A New Digital Control Algorithm for Dual-Transistor Forward Converter

In this paper, a new digital control algorithm is presented to improve the dynamic performance of the dual-transistor forward converter (DTFC) during a transient event. The algorithm uses a linear control scheme under the stable-state condition and the charge balance control scheme under the transient condition. Based on the principle of capacitor charge balance, the proposed algorithm predicts the switch over time to achieve optimal transient response for a DTFC, thus the minimal voltage derivation and recovery time are achieved when the load current has a step change. Compared with a conventional voltage mode controller, the proposed algorithm provides a much better dynamic performance. Furthermore, simulation and experiment results demonstrate the effectiveness of the algorithm.
Digital control and simulation of parallel current mode for Buck converter

Parallel current mode control algorithm for DC-DC converters is introduced in this paper. This control strategy is composed of two parallel terms: voltage term and current term which is calculated based on the input voltage, inductor current and output voltage. The new duty cycle algorithm requires only one multiplication, one division and three additions in digital implementation. The simulation results demonstrate that parallel current mode control has superior steady-state response over the conventional current mode control, and maintains a good dynamic response. A 400-kHz switching frequency Buck converter based on FPGA implementation shows that the new duty cycle control strategy is optimal for digital control.
Caputo fractional derivative estimation for a class of signals satisfying a linear differential equation

This paper aims at estimating the Caputo fractional derivatives for a class of signals satisfying a linear differential equation. For this purpose, an estimator for the initial conditions of the studied signal and an fractional order differentiator for the Riemann-Liouville fractional derivatives are needed. Firstly, an algebraic integral formula for the initial conditions is introduced using a generalized modulating functions method. Then, an estimator for the initial conditions is derived using a numerical integration method in discrete noisy case. Finally, a numerical example illustrates the accuracy and the robustness of the proposed method, where a recent fractional order differentiator for the Riemann-Liouville fractional derivatives is considered.
A new power factor correction (PFC) control method suitable for low cost DSP

One main barrier to implement digital control for power factor correction (PFC) is the limited switching frequency due to the limited processor speed. A new digital PFC control method is proposed to solve this problem. For convention digital methods, the duty cycle is calculated every switching period. The new digital PFC control method uses an optimization algorithm to generate all of the required duty cycles for one half line period at one time in advance, which is based on the input current and duty cycles in the previous half tine periods. Total Harmonic Distortion (THD), which is directly related to the power factor, is determined as the objective function. Gradient descent is used as the optimization algorithm to minimize the THD and improve the power factor. The proposed new digital PFC control strategy overcomes the problem of limited switching frequency due to limited DSP speed. Simulation results show that unity power factor is achieved using the proposed method.
A dynamic network anomaly detection method based on trend analysis

Detecting abnormal behavior during network evolution is an important and challenging data analysis task at present, it is named as dynamic network anomaly detection in this paper. The network abnormal behavior differs from that of normal behavior, the probability of occurrence stays relatively low but may cause serious damages once happened. This paper takes the topological structure of the network as the research object and identifies the network anomaly through the change of network structure. Based on Cox-stuart test, we put forward a new type of method to detect dynamic anomaly. This method refers to an alarm of monitoring the trend change of the network structure parameters. Finally, an experiment was carried out in the real dynamic network-Enron Email Network, which verified that the dynamic network anomaly detection method proposed in this paper can effectively detect the network anomaly behavior.
Adaptive Controller Design-Based ABLF for a Class of Nonlinear Time-Varying State Constraint Systems

In this paper, we address an adaptive control problem for a class of nonlinear strict-feedback systems with uncertain parameter. The full states of the systems are constrained in the bounded sets and the boundaries of sets are compelled in the asymmetric time-varying regions, i.e., the full state time-varying constraints are considered here. This is for the first time to control such a class of systems. To prevent that the constraints are overstepped, the time-varying asymmetric barrier Lyapunov functions (TABLFs) are employed in each step of the backsstepping design and we also establish a novel control TABLF scheme to ensure the asymptotic output tracking performance. The performances of the adaptive TABLF-based control are verified by a simulation example.
Computational study of external fixation devices surface heating in MRI RF environment

Heating effect by external fixation devices under MRI RF field was studied numerically for both 1.5-T and 3-T MRI systems. It is found that changing insertion depth and pin spacing could largely affect the surface heating level. In 1.5-T MRI, smaller insertion depth and larger pin spacing will produce larger temperature rise. However, for 3T system, the relation is not very clear when insertion depth became larger than 5cm or when pin spacing became larger than 20cm. Effect of connection bar material on external fixator is also studied and the heating mechanism of the device is analysed.
Design and simulation of a macro-micro dual-drive high acceleration precision XY-stage for IC bonding technology

A macro-micro dual-drive high acceleration precision XY-stage is presented in this paper. Combining macro with micro actuator, a system of large workspace and high acceleration with high resolution of motion is developed. Two linear voice coil motors (VCM) are used into the macro motion, and two PZT-driven micro stages of high frequency are mounted on each motor to compensate the position error. A novel elastic decoupling mechanism is used in the stage to avoid the moving gap. The high resolution linear encoder is integrated into the closed-loop feedback, which is used to measure the position of the output end of macro stage and micro stage. By using the mechanical dynamic simulation and FEA method, the decoupling mechanism and the micro mechanism are optimized, and the dynamic characteristics of the high acceleration stage are investigated, which is based on the rigid-flexible dynamic analysis of mechanical system. The simulation results show that this new configuration allows a workspace of 25/spl times/25mm/sup 2/ and an acceleration exceeding 100m/s/sup 2/ with a resolution of motion better than 10nm. The significantly improved performance of the XY-stage can meet the requirement of the rapid development of IC bonding technology.
Adaptive NN Control Using Integral Barrier Lyapunov Functionals for Uncertain Nonlinear Block-Triangular Constraint Systems

A neural network (NN) adaptive control design problem is addressed for a class of uncertain multi-input-multi-output (MIMO) nonlinear systems in block-triangular form. The considered systems contain uncertainty dynamics and their states are enforced to subject to bounded constraints as well as the couplings among various inputs and outputs are inserted in each subsystem. To stabilize this class of systems, a novel adaptive control strategy is constructively framed by using the backstepping design technique and NNs. The novel integral barrier Lyapunov functionals (BLFs) are employed to overcome the violation of the full state constraints. The proposed strategy can not only guarantee the boundedness of the closed-loop system and the outputs are driven to follow the reference signals, but also can ensure all the states to remain in the predefined compact sets. Moreover, the transformed constraints on the errors are used in the previous BLF, and accordingly it is required to determine clearly the bounds of the virtual controllers. Thus, it can relax the conservative limitations in the traditional BLF-based controls for the full state constraints. This conservatism can be solved in this paper and it is for the first time to control this class of MIMO systems with the full state constraints. The performance of the proposed control strategy can be verified through a simulation example.
A Novel LSB Matching Steganalysis Detection Algorithm Based on Characteristics of the Second Order Difference Markov

For the LSB matching steganography with high security, the author has calculated the second-order differential of the image pixels on horizontal and vertical directions, obtaining the differential matrix and taking it as sensitive feature extracting source. Then, by extracting the second-order Markov transformation matrix of the differential matrix as the features, this paper proposed a LSB matching steganalytic algorithm. Experimental results show that: compared with existing algorithm, the proposed algorithm can not only preserve the high detection accuracy, but also speedup the detection process in a large extent, which enhance the performance and practicability of the steganalytic algorithm.
Analysis and design of a 30 MHz resonant SEPIC converter

This paper presents the analysis and design of a resonant SEPIC converter operating at 30 MHz. With the conventional design method, tuning the amplitude and phase of the fundamental input voltage and current affect each other so that the design procedure is trial-and-error. An improved design method is proposed by re-dividing the resonant SEPIC topology and defining the new variables to realize the independent tuning of the amplitude and phase. The loss analysis is provided. A 15 V input, 14 W/28 V output, 30 MHz prototype has been built to verify the proposed design method. The prototype achieves the efficiency above 80% over a wide load. Furthermore, a novel structure of the PCB embedded inductors is used in a 25 W prototype to further improve the power density.
Base station location protection in wireless sensor networks: Attacks and defense

A base station (BS) is the controller and the data receiving center of a wireless sensor network. Hence, a reliable and secure BS is critical to the network. Once an attacker locates the BS, he can do a lot of damages to the network. In this paper, we study the BS location protection issue. First, we present a new attack on BS: the Parent-based Attack Scheme (PAS). The PAS can locate a BS within one radio (wireless transmission) range of sensors. Different from existing methods, the PAS determines the BS location based on parent-child relationship of sensor nodes. The PAS cannot be defended by existing BS protection schemes. To defend against the PAS, we design a new parent-free (PF) secure routing protocol for sensor networks. Our simulation results show that the PF protocol has small communication and computation costs, while ensuring the security of the BS.
DC-link capacitor voltage balancing technique for phase-shifted PWM-based seven-switch five-level ANPC inverter

The Five-Level Active-Neutral-Point-Clamped (5L-ANPC) inverters are receiving more attentions as one of preferred solutions for medium and high power applications because of the combination of the features of the conventional Flying-Capacitor (FC) type and Neutral-Point-Clamped (NPC) type inverters. This paper proposes a new DC-link capacitor voltages balancing technique for the Seven-Switch 5L-ANPC (7S-5L-ANPC) topology which is using Phase-Shifted PWM (PS-PWM) modulation method. Based on the power relationship between DC-link capacitors and FC, the proposed technique adjusts the duty cycles of redundant 1-level switching states to balance the DC voltage without changing the output performance. The proposed technique can be applied to any 5L-ANPC inverter topologies. A 1 kW single-phase 7S-5L-ANPC inverter experimental prototype is built to verify the effectiveness of the proposed DC-link capacitor voltages balancing technique.
A new digital capacitor charge balance control algorithm for Boost DC/DC Converter

In this paper, a new non-linear digital control algorithm is proposed for Boost DC-DC converters to achieve excellent dynamic performance which cannot be obtained by using conventional linear control method for its bandwidth limitations. Using the concept of capacitor charge balance, the proposed algorithm predicts an improved transient response for a Boost DC-DC converter during the large signal load-current step change. The equations used to calculate the improved transient time and the improved duty cycle series are presented. Simulation and experimental results show that the proposed method produces excellent transient performance, including the small output voltage overshoot/undershoot and the short recovery time, which is much superior over that of a conventional voltage mode controller.
An Improved Implicit Token Passing Algorithm for DAP-NAD in MIL-STD-188-220C

In this paper, we proposed an improved NAD (network access delay) algorithm for MIL-STD-188-220C that is named as DAP-NAD-CJ. In our new algorithm, the implicit token passing scheme was modified so that tokens can effectively jump over stations without message, and thus can find active stations as fast as possible. Firstly, we analyzed our algorithm mathematically in the case of single priority network. Then simulations were presented in a multi-priority network. Mathematical and simulation results showed that our DAP-NAD-CJ algorithm outperforms DAP-NAD and DAP-NAD-R algorithms
Analysis of market power of oligopolistic generators

A Nash-Cournot model, based on generating units' marginal cost function, is set up to study oligopolistic generators' market power and pricing strategy in the unilateral open electricity market. Factors that affect generators' market power are analyzed. We find that in unilateral open electricity markets, oligopolistic generators always tend to raise its bidding price by making full use of its market power, which raise the overall electricity price in the whole market. In order to reduce the generators' market power, the whole market total installation capacities must be increased and there must be no one generator whose capacity is too much relative to others. Further, measures must be taken to effectively monitor the operation of the market and to motivate the generators to undertake cost-cutting strategies through technical innovation. Reasonable competitive bidding system must also be set up to prevent collusion.
A novel Non-Isolated Two-Phase Full Bridge topology for VRM applications

In this paper a new full bridge topology called the two-phase non-isolated full bridge (NFB) is introduced. The proposed two-phase NFB can handle the same power as two parallel one-phase NFBs, 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% & 82% efficiency at 1 MHz full load (1V/80A) respectively. This is compared to 81.8% efficiency of the two paralleled one-phase NFBs. At light load (1V/10A), a 4% efficiency improvement is achieved. Experimental results demonstrate that compared with two paralleled one-phase NFBs the two-phase NFB is able to achieve better efficiency with a simplified power train circuit and reduced cost.
An Optimized Structure of 4H-SiC U-Shaped Trench Gate MOSFET

In this paper, an optimized structure of 4H-SiC U-shaped trench gate MOSFET (UMOSFET) with low resistance is proposed. The optimized structure adds an n-type region, wrapping the p+ shielding region incorporated at the bottom of the trench gate. The depletion region formed by the p+ shielding region reduces greatly for the high dopant concentration of the added region. This added region also conducts electrons downward and expands the electrons to the bottom of the p+ shielding region. We discussed the influence of dopant concentration and the width of the added region on the breakdown voltage (BV) and the ON-resistance in this paper. A reasonable size and an optimized concentration were chosen for the added region in our simulation. The channel inversion layer mobility was set to 50 cm2/Vs, and the specific ON-resistance and the BVwere 1.64 mΩ·cm2 (VGS = 15 V, VDS = 1 V, and no substrate resistance was included) and 891 V, respectively, using the numerical simulation.
A new feature detection method based on gray gradient sequence

Based on the discreteness of existing form and the continuity of energy distribution of digital image, this paper presents a new local feature detection method. The proposed method realizes the local feature detection of optical image, radar image and infrared image based on gray gradient sequence and 1-D Hilbert-huang transform method. Experimental results show that this method can describe and detect common local feature of single-sensor images and multi-sensor images efficiently for image registration application.
A New Resonant Gate Drive Circuit for Synchronous Buck Converter

This paper proposes a new resonant gate drive circuit for driving both the control metal oxide semiconductor field effect transistor (MOSFET) and synchronous MOSFET in a synchronous buck converter. The circuit can recover more than 70% of the conventional gate drive loss. More importantly, the driving circuit can also reduce the switching loss. It charges and discharges the gate of MOSFET at a constant current during switching interval. Other advantages of the proposed circuit include better noise immunity for dv/dt turn on, less sensitive to parasitic track inductance. The experimental prototype shows that the loss reduction is 10% of the output power for 12 V input, 1.5 V/15 A output with switching frequency of 1 MHz.
Channel Error Estimation Methods for Multichannel SAR Systems in Azimuth

With the combination of digital beamforming (DBF) processing, multichannel synthetic aperture radar (SAR) systems are promising in high-resolution wide-swath imaging. However, the mismatch among channels will degrade the performance of DBF. In this letter, two novel methods are proposed to estimate channel errors for multichannel SAR systems in azimuth. The first method is based on the fact that the space spanned by the signal eigenvectors is equal to that spanned by the practical steering vectors. In the second method, the channel errors are directly estimated by the antenna patterns without matrix decomposition and inversion processing. Both the theoretical analysis and experiments demonstrate the effectiveness and efficiency of these two methods.
Automatic wire bonder designed for MEMS packaging

This paper introduces zoom microscope into the microscope positioning system to settle the contradiction between microscopepsilas visual range and depth of field. In the whole bonding application, bond targetspsila identification and orientation are the most important aspects for full-automation. Multiple scale images go through various image processing programs, and finally different bond targets are identified and positioned This measure is called ldquoglobal-coarse and local-precise orientationrdquo, with which full-automation bonding is realized. A zoom microscope based micro-positioning system was used to capture the multiple magnification images. The requirement for real-time auto-focusing for zoom microscope is proposed based on the analysis of zoom microscope model.