nils-herrmann/clean_scirepeval huggingface dataset:
Design of the ITER 170 GHz gyrotron gun

The optimized design of the ITER 2 MW, 170 GHz, CW, coaxial cavity gyrotron gun is presented. Simulations show that a good beam quality can be attained (pitch-ratio spread /spl delta//spl alpha/ of /spl sim/1.9%, electron beam thickness in the cavity of /spl sim/0.45 mm) and confirm previous results that the lowest /spl delta//spl alpha/ values are achieved at an intermediate type of the electron flow. Adjusting the currents through the gun coils results in considerable variation of the beam pitch-ratio /spl alpha/. This can compensate the deviations of /spl alpha/ from its specified value of 1.3 for changes in magnetic field and axial alignment.
A study on routing performance of 802.11 based wireless mesh networks under serious attacks

In recent years, wireless mesh networks based on 802.11 technologies have been deployed in real environment with huge interesting applications. Beside their advantages, some critical technique challenges have been remained because they heritage some disadvantage characteristics of ad hoc networks. In which, routing issue is the most challenge due to its importance and complexity related with network performance. Since WMNs deployment in practical scenario such as community network, routing issues have to face with more challenges which are coming from security problems. This paper studies on routing protocol performance of 802.11 based wireless mesh network under serious attacks, the results point out that the routing protocol performance is different under the same attack conditions and heavily depend on where attackers located in the network.
Acoustic emission sensor using liquid-on-beam structure

This paper reports on a new approach for Acoustic Emission (AE) sensor, using the multi-layer structure of dimethylpolysiloxane (PDMS)-cover / polyparaxylylene (or Parylene)/ liquid/ beam/ air to conduct vibration propagating medium to the piezo-resistive sensing beam. As the liquid droplet is placed in the middle of the solid sensor cover and the beam, it flattens the Eigen-resonant effect of the beam on vibration sensing process. Therefore, the proposed sensor demonstrated an extra-wide range of measurable frequency of interest up to 10MHz. The pencil lead breaking test demonstrates the ability of this sensor in measuring AE signals on a wide frequency band.
An enhanced sliding-mode control for a pneumatic-actuated teleoperation system

This paper presents an enhanced sliding mode control for pneumatic master-slave teleoperation systems that are actuated by low-cost solenoid valves. A five-mode sliding control is incorporated into position-position, force-force, and force-position teleoperation architectures. While on/off valve pneumatic actuators have previously been modeled as having three discrete operating modes, an extension to five discrete control levels as proposed here helps to improve the actuator dynamic performance and reduce the switching activities of the valves. Stability and transparency analyses of the closed-loop teleoperation system are carried out. The proposed control design is experimentally tested on a single-degree-of-freedom pneumatic teleoperation system. Experimental results demonstrate high accuracies in terms of position and force tracking in the teleoperation system.
Authenticated Key Exchange, Signcryption and Deniable Signcryption Protocols Based on Two Hard Problems

Arazi was the first author to propose the integration of a key exchange protocol with a digital signature algorithm. Other authors have subsequently proposed methods to increase the level of security and achieve the necessary properties of authenticated key exchange protocols. However, these proposals exhibit several weaknesses and the majority of these protocols are based only on a single hard problem. In this paper, we propose a new secured key exchange protocol which is based on two hard problems. We then extend this to a signcryption protocol and a deniable signcryption protocol. These protocols represent the first steps in a new direction, but they are designed based on two hard problems. The security proofs for the new protocols confirm their novelty and security.
An Approach of Deriving Relative Sensitivity Profiles for Image Reconstruction in MRI

The determination of accurate coil sensitivity profiles is crucial for parallel MRI approaches such as SMASH, SENSE, and SPACE-RIP. In classical SENSE the profiles are determined using a so-called calibration scan through division of array and body coil images sampled with full field of view (FOV). However, as this relies on the availability of a body coil, there exist many situations where this is not possible. This research work outlines the method of calculating sensitivity maps of array coil elements relative to one particular reference array element using complex weighting coefficients, based on a few lines of central k-space data, similar to those used in the GRAPPA method. The approach provides relative sensitivities with a smooth boundary between objects and image background. When the relative sensitivities are used in a SENSE algorithm, referred to as relative SENSE (rSENSE), the reconstructed image corresponds to a fully sampled image taken by the reference array element. The images of other elements are then obtained by multiplying the reference image by their relative sensitivities. Results provided for the proposed approach of deriving relative sensitivity profiles for fast image reconstruction show that the technique provides images with fewer artifacts. The findings are established with reference to SFDD, SPDD, and GRAPPA.
An efficient camera-based surveillance for fall detection of elderly people

Falls and consequent injuries among the elderly population are major public health problems that often require medical attention. Every year, the world has more than 30% of people aged over 65 fall and most of them could not stand up without assistance promptly. The long laying makes the injury even more seriously. A system of monitoring the status of the elderly based on image processing technology can help mitigate this situation. This paper proposes an efficient camera-based fall detection system for senior people. We present our preliminary results in our effort to create an emergency alarming system for fall detection aiming at simple, real-time response and high performance. Images from the camera are processed by computer. Status of elderly persons are detected based on combination of two features: aspect ratio and fall angle. Remarkable accuracy rate of the system is as much as 92.5% .
Calibration against orientation drifts in a real-time Embedded inertial Measurement Unit

This paper presents the development and implementation of an Inertial Measurement Unit (IMU) where Micro-Electro-Mechanical System (MEMS) sensors are used to measure angular velocity and acceleration, a magnetic sensor (magnetometer) is used to calibrate against orientation drifts, a Global Positioning System (GPS) signal receiver is integrated and an extended Kalman filter algorithm is applied for real time signal processing to estimate the attitude of an object in space. The MATLAB/Simulink Embedded tool and C30/MPLAB Compiler are used to design, compile, and download directly into the target. An update rate of 100Hz with real time floating point processing can be achieved for the extended Kalman algorithm using a Microchip 16 bit dsPIC33f256 microcontroller.
A star pattern recognition algorithm for satellite attitude determination

To determine the satellite attitude in space, various attitude sensors are used. Among them, the most accurate sensor is the star tracker. In this paper, a novel star pattern recognition algorithm in the “lost in space” mode is presented. The proposed method improves the searching speed by arranging the large star catalogue using a search tree data structure. To further improve the processing speed, the star image is processed at the grid level instead of pixel level. The results from the study demonstrate that the proposed approach has significantly reduced the average run-time by 50% as compared to the conventional methods while still achieve slightly better star recognition accuracy at 95.07%.
Design and Experimental Verification of Hip Exoskeleton With Balance Capacities for Walking Assistance

Most current hip exoskeletons emphasize assistance for walking rather than stability. The goal of this paper is to develop a novel, high-power, self-balancing, and passively and software-controlled actively compliant hip exoskeleton that can assist with movement and maintain balance in both the sagittal and frontal planes. The developed hip exoskeleton includes powered hip abduction/adduction and hip flexion/extension joints. Each actuation unit employs a modular and compact series elastic actuator (SEA) with a high torque-to-weight ratio. It provides mechanical compliance at the interface between the exoskeleton and the wearer to ensure safety and a natural gait in the coupled wearer-exoskeleton system. A new balance controller based on the extrapolated center of mass concept is presented for maintaining walking stability. This controller reacts to perturbations in balance and produces a compliant guidance force through a combination of the passive elasticity of the SEA and active compliant control based on adaptive admittance control. The function of the hip exoskeleton is not to override human control, but rather to involve the wearer in movement control in order to avoid conflicts between wearer and exoskeleton. Our preliminary experiments on a healthy subject wearing the hip exoskeleton demonstrate the potential effectiveness of the proposed hip exoskeleton and controller for walking balance control.
Compressive and cooperative sensing in distributed mobile sensor networks

In this paper, we propose an algorithm to support distributed mobile sensors to collect data in sensing areas needing to be observed. The algorithm exploits random positions of mobile sensors to measure the area and applies compressive sensing (CS) to reconstruct all sensed data based on a certain number of CS measurements. At a time instant, the sensors add all readings within their sensing range and exchange their accumulative readings to their neighbors within a sensor communication range. Each CS measurement created at a time is a sum of all data measured by a group of connected sensors. We further analyze and formulate expression for power consumption for communications in the network. The measurement matrix, the number of mobile sensors, the sensing range and the communication range are analyzed and suggested for the networks to consume the least power.
An automatic decoupling control system for ship harbor maneuvers and its robustness evaluation

Presented and discussed in this paper are mathematical model used for expressing ship motions, application of decoupling control methodology to construct the controller and corresponding designing issues. Simulation results for a Very Large Crude Carrier (VLCC) in a typical harbor maneuver are given to verify the designing of the controller. Excellent effects of the controller are shown by very good simulation results of ship motions during several 180/spl deg/ turning maneuvers under various strong wind conditions. Robustness of the controller against parameter uncertainty, strong environment disturbances such as strong wind and currents is also studied and presented in this paper.
Denoising of MR spectroscopic imaging data with spatial-spectral regularization

Low signal-to-noise ratio has been a significant limitation for clinical applications of magnetic resonance spectroscopic imaging (MRSI). This paper investigates a new scheme for denoising MRSI data, incorporating both an anatomically-adapted spatial-smoothness constraint and an autoregressive spectral constraint within the penalized maximum-likelihood framework. Both theoretical analysis and simulation results are provided to characterize the denoising performance of this approach.
A new type of PWM rectifier with function of harmonic suppression and reactive power compensation

Aiming at solving the problem of harmonic suppression and reactive power compensation, the traditional method is to use reactive power compensation and active power filter. This paper has promoted a new type of Pulse Width Modulation (PWM) rectifier that has the function of harmonic suppression and reactive power compensation which also describes the control method in detail. The paper attempts to bring up instantaneous reactive power ip-iq theory and reactive detection algorithm on the basis of the PWM rectifier. At the same time, it proposes voltage-current dual closed-loop control system using fuzzy PI hybrid control to regulate the DC bus voltage. Thus, not only does the PWM rectifier have the function of rectifying effect, but also achieve the harmonic suppression and reactive power compensation in the power grid. At last analyze the energy flow process and uses the PSIM software simulation to verify functional effects. The simulation results show that PWM rectifier improves the output current waveform and doesn't need additional compensation device.
COFALE: An Authoring System for Supporting Cognitive Flexibility

Constructivism is a learning theory that states that people learn best when they actively construct their own knowledge. A significant number of ICT-based constructivist learning systems have been proposed in recent years. A critical problem related to the design and use of this kind of systems has been the lack of a practical means to facilitate the instructional design process. Our research aims to help designing truly constructivist learning environments. Our approach is based on a set of operational criteria for certain aspects of constructivism: We use these criteria as a useful pedagogical framework to provide tools and guidelines facilitating the instructional design process. One facet often mentioned as being strongly relevant to constructivism is cognitive flexibility. This paper presents COFALE, a new domain-independent e- Learning platform that could be used to build learning environments supporting cognitive flexibility, and an example of its use: the design of a course on recursion.
A hybrid solid state induction modulator for klystrons

A solid state induction modulator was designed and operated for the Next Linear Collider accelerator project at SLAC ( to drive 8 X-band klystron. With the redirection of the NLC physics program, the remaining hardware from the DFM (Design for Manufacturability) modulator was combined with existing pulse transformers to fabricate two Hybrid Solid State Induction Modulators, one to drive two XK5 klystrons at 420kV 400A 1.5 μS and a second modulator to drive a single 5045 klystron to 360kV 430 A 3.5 μS. These modulators use the induction section to drive a conventional pulse transformer. Both these modulator are smaller and operate at a lower voltage than the thyratron driven PFN equivalent. These modulator have been fabricated, tested, and are in operation. The design, implementation, and results will be describe in the paper.
An Efficient Method for Filtering Image-Based Spam

Spam e-mail with advertisement text embedded in images presents a great challenge to anti-spam filters. In this paper, we describe a fast method to detect image-based spam e- mail. Using simple edge-based features, the method computes a vector of similarity scores between an image and a set of templates. This similarity vector is then used with support vector machines to separate spam images from other common categories of images. Our method does not require computationally expensive OCR or even text extraction from images. Empirical results show that the method is fast and has good classification accuracy.
Crystallization Process and Magnetic Properties of Amorphous  ${\rm NiFe}_{2}{\rm O}_{4}$  Nanoparticles

We investigate the crystallization process of NiFe2O4 nanoparticles prepared by microwave heating technique, which were then characterized using X-ray diffraction, high-resolution transmission electron microscopy, the differential scanning calorimetry, Raman scattering, Fourier transformed infrared spectra (FTIR), and magnetic measurements. The results showed that crystallization of the amorphous NiFe2O4 nanoparticles occurred at around 300 °C. The best crystallization quality would be obtained by annealing the sample at 500 °C. After crystallization, the sample shows ferromagnetic behavior with a saturation magnetization of about 30 emu/g. The FTIR and Raman measurements also provided further information about the crystallization process and the phase transformation of the NiFe2O4 nanoparticles.
Adaptive energy-saving strategy for activity recognition on mobile phone

Most existing mobile devices nowadays are powered by a limited energy resource. With the tendency using machine learning on mobile devices for activity recognition (AR), recent achievements still remain restrictions including low accuracy and lacking of evidences about power consumption of feature extraction and classification. Moreover, keeping constantly a high sampling frequency was the most power consuming factor. In this paper, we contribute a novel method for extracting features in time domain and frequency domain. These features are then classified by Support Vector Machine (SVM). Prototypes of the proposed methods are then implemented on a cell phone to measure power consumptions. To reduce the energy overhead of continuous activity recognizing, we propose an adaptive energy-saving strategy by selecting an appropriate combination of flexible frequency and classification feature for each individual. The self-construct data and SCUTT-NAA dataset are used in our experiment. We achieved an overall 28 percent of energy saving in activity recognition on mobile phone.
A Four-Component Decomposition Model for PolSAR Data Using Asymmetric Scattering Component

This paper describes a polarimetric information extraction method using PolSAR data. The proposed method is based on the covariance matrix and intended to be applicable to the general nonreflection symmetric scattering case that the copolar and cross-polar correlations are not close to zero. Asymmetric scattering term, which can entirely represent the asymmetric information of PolSAR data, is proposed to describe the nonreflection symmetric scattering caused by complicated shape targets or man-made structures in urban areas. Using this asymmetric scattering term, together with surface, double-bounce, and volume scattering terms, the new four-component scattering power decomposition method is then proposed, which can fully utilize all the parameters contained in the PolSAR data. It is found that asymmetric scattering is predominant in urban areas and close to zero in natural distributed areas. Although designed for nonreflection symmetric scattering case, the decomposition method can also deal with the reflection symmetry case, since it automatically becomes Freeman three-component decomposition method in natural areas. The E-SAR L-band full-polarized data acquired over Oberpfaffenhofen area in Germany and the CONVAIR-SAR C-band data acquired over Ottawa area in Canada are applied to validate the proposed decomposition method. The results of the experiments show that the proposed method has better performance than the four-component decomposition model in distinguishing different types of terrains.
Angular difference measure between tomographic projections taken at unknown directions in 2D

This paper introduces a new measure for estimating the angular difference between two tomographic projections belonging to a set of projections taken at unknown directions. The measure is potential for many applications such as projection refinement or projection classification, which are important in the process of tomographic reconstruction. Our measure relies on the construction of a neighborhood graph for projection moments, the calculus of the angular difference for neighboring projections and the computation of geodesics on this graph. The accuracy and the robustness of our measure is shown on a test database including 50 2D gray-level images at different resolutions and with different levels of noise.
Design and performance of wideband, low-noise, millimeter-wave amplifiers for microwave anisotropy probe radiometers

Differential pseudo-correlation radiometers covering 20-25 GHz, 28-37 GHz, 35-46 GHz, 53-69 GHz and 82-106 GHz are used in the Microwave Anisotropy Probe (MAP) mission to be launched in late 2000. This paper describes the design, performance and manufacturing of 140 InP HFET amplifiers suitable for cryogenic cooling which exhibit low noise performance and complex gain match over the given radiometer bandwidths (typical noise temperature of 90 K, or 1.2 dB noise figure, for W-band amplifier at 80 K ambient).
Design and implementation of a 62–77 GHz low noise amplifier in 90 nm CMOS

A 62 to 77 GHz broadband low noise amplifier (LNA) using a low-cost 90 nm standard CMOS technology is designed and implemented. From the measured results, the proposed LNA has a peak gain of 10dB at 70 GHz, a 3dB bandwidth is 15 GHz from 62 to 77 GHz, an output reflection coefficient (S22) is better than -4dB, an input reflection coefficient (S11) is lower than -10dB and the power consumption of the LNA is 17.6 mW. In addition, the simulated noise figure (NF) is 7.6 dB at 70 GHz and lower than 8.5 dB entire bandwidth.
An efficient decomposition of human-written summary sentence

The task of human written decomposition is based on the pair of original documents and its summary to define these components in a summary sentence come from somewhere in the document. This task aims to satisfy three requirements as follows: 1) Whether it is constructed from cutting and pasting? 2) Which components in the sentence come from the original document? 3) Where in the document do the components come from? The result of a decomposition program is considered as training data and data evaluation for reduction and combination steps in cut and paste summarization system. We propose a method to enhance the accuracy of decomposition task through checking position and semantic measure for each word within a summary sentence. The model we used in the paper is extended from the hidden Markov model described by Hongyan Jing and K.R. MacKeown, (1999). Experiment results in the DUC data shows that the proposed method is efficient.
An X-band high-efficiency ion-implanted MMIC power amplifier

A state-of-the-art X-band high-efficiency monolithic power amplifier has been demonstrated. An average output power of 3.6 W at an average 41% power-added efficiency over a 40% bandwidth from 7.0 to 10.5 GHz has been achieved. An excellent average power density of 500 mW/mm and peak power density of 550 mW/mm have been measured across this bandwidth.<<ETX>>
A comprehensive analysis study about harmonic resonances in megawatt grid-connected wind farms

This paper presents a comprehensive analysis technique about harmonic resonance issues in megawatt grid-connected wind farms where the doubly fed induction generator (DFIG) is used. Wherein, firstly, the background theories of the series resonance, parallel resonance and their impacts on the electric system are described. Moreover, a suitable equivalent circuit of typical grid-connected DFIG wind farms for analyzing impedance in the frequency domain is proposed. Then, mathematical formulas are introduced detail to determine exactly orders and amplifications of the voltage and current distortions on both the medium-voltage (MV) bus and low-voltage (LV) bus. Lastly, results obtained from the proposed equivalent circuit and impedance analysis technique are compared to other results achieved with the detailed wind farm simulated in MATLAB/SimPowerSystems. As well, many different operation cases of the illustrative grid-connected DFIG wind farm, including parametric variations, are also examined to evaluate the accuracy and effectiveness of the proposed analysis technique..