nils-herrmann/clean_scirepeval huggingface dataset:
Biometric authentication via keystroke sound

Unlike conventional “one shot” biometric authentication schemes, continuous authentication has a number of advantages, such as longer time for sensing, ability to rectify authentication decisions, and persistent verification of a user's identity, which are critical in applications demanding enhanced security. However; traditional modalities such as face, fingerprint and keystroke dynamics, have various drawbacks in continuous authentication scenarios. In light of this, this paper proposes a novel nonintrusive and privacy-aware biometric modality that utilizes keystroke sound. Given the keystroke sound recorded by a low-cost microphone, our system extracts discriminative features and performs matching between a gallery and a probe sound stream. Motivated by the concept of digraphs used in modeling keystroke dynamics, we learn a virtual alphabet from keystroke sound segments, from which the digraph latency within pairs of virtual letters as well as other statistical features are used to generate match scores. The resultant multiple scores are indicative of the similarities between two sound streams, and are fused to make a final authentication decision. We collect a first-of-its-kind keystroke sound database of 45 subjects typing on a keyboard. Experiments on static text-based authentication, demonstrate the potential as well as limitations of this biometric modality.
An improved fog-degraded image enhancement algorithm

In fog weather, Images captured by outdoor surveillance system degrade significantly and suffer from poor contrast. This paper presents an improved algorithm for enhancing fog-degraded image contrast in which a moving mask is used. By assuming the pixels in a mask having same scene depth, the algorithm applies the modified partially overlapped sub-block histogram equalization to implement contrast enhancement in every mask. It involves two steps: first, sky region is segmented in order to restrain over-enhancement in the flat region and reduce noise; then, remove the sky pixels in masks and modify the histogram information in mask, thus the modified partially overlapped histogram equalization transformation function for enhancement can be gotten. This paper also proposes a novel fuzzy edge detection algorithm to evaluate above contrast enhancement effect. Experiments on many fog-degraded images demonstrate that the proposed improved algorithm is simple and effective in contrast enhancement of fog-degraded images.
Vector-Based Low-Delay Forwarding Protocol for Underwater Wireless Sensor Networks

underwater wireless sensor networks are new arising research hotspot. The paper first analyses the related vector-based forwarding protocols for underwater wireless sensor networks, and puts forward a novel data forwarding strategy for the candidate nodes, to reduce the delay in the forwarding nodes and improve the successful rate, so as to satisfy the requirements in the low delay environment. The experimental results show the obvious improvement in low delay and successful rate.
Consistency analysis of DFIG wind generation models in PSS/E and PSASP

With rapid increase of wind power installed capacity, the operation mode of power system has changed greatly, it is necessary to include modeling and simulation based on wind turbines and farms. Numerical simulation plays a unique role in power system operation and control, and its accuracy turns out to be the focus of electric industry. PSASP and PSS/E, as two main sorts of simulation analysis software at home and abroad respectively, both enable wind turbines electromechanical transient simulation. In this paper, Detailed comparisons are made between Doubly-fed induction generator (DFIG) in PSS/E and PSASP. Finally, simulative results of power system including the models are compared and analyzed.
Characteristic analysis and application of the microstrip line on L-SIAD

In this paper, a simple CAD formula is derived by synthetic asymptote for the microstrip line on localized substrate integrated artificial dielectric (L-SIAD). This formula is then applied for the design of several components, such as, an impedance transformer, a dual-band power divider, an ultra-wideband (UWB) band-pass filter, and a wide stop-band low-pass filter on L-SIAD structure. The simulation and measurement results show good agreements.
Research on insulation characteristics of multi-break in series extra high voltage vacuum circuit breaker

Multi-break in series is the measurement applied in the design of the extra high voltage vacuum circuit breakers (EHV VCBs). Because of the existence of the coupling and transient variation of the multi-physical fields, the multi-break in series is the uniformed large space-time field system covering the multiple physical parameters. And the insulation performance for each break in the series system change a lot than one break case, and the investigations on the unknown factors are necessary. Based on the application of the EHV VCB applied in the system, the dynamic insulation coordination property covers the dynamic insulation of each break and the design of the multi-break in series. In this paper, the 3D electric field of the triple-break vacuum interrupter (VI) in series is numerically simulated using finite element method (FEM). And the location of the maximum electric field strength and the field distribution along the surface of the movable and fixed contact are calculated and figured out. By the comparative analyses with different insulation structures in series, the variations of the electric field strength are obtained and illustrated. Moreover, by introducing the shielding covers and parallel capacitors, the design of each 72.5 VI unit is accomplished and the insulation property of the 220kV triple-break in series EHV VCB is analyzed.
Magnetic field analysis of hybrid AMF-TMF contact for VI

The contact structure of the interrupter for the DC vacuum circuit breaker (VCB) is proposed in this paper. Based on the different structure, magnetic properties of the transverse magnetic field (TMF) and axial magnetic field (AMF) contacts, a hybrid AMF-TMF cup shape contact is presented. The steady magnetic field and the residual magnetic field has been analyzed using the finite element method (FEM). From the simulation results, it can be seen that: for the cognition of steady magnetic field, the middle region TMF of the hybrid AMF-TMF cup shape contact is enhanced, and the AMF in the central region is increased significantly. The RMF value for the novel hybrid cup is much smaller than that of the traditional cup, which is more favorable for the metal vapor diffusion and effective dissipation of the arc energy.
We Know Who You Are: Discovering Similar Groups Across Multiple Social Networks

People use various online social networks for different purposes. The user information on each social network is usually partial. Thus, matching the users across these multiple online social networks is of great significance for providing new services as well as new insights on user behaviors. Recent research shows that group structure widely exists on social networks, in which members work together with certain purpose and are more influential than individuals on online social networks. Previous works provide outstanding solutions for mapping individuals, but few ones pay attention to the study of groups across multiple social networks. To address the research gap, we first aim to propose an effective method to detect similar group across multiple social networks. The method mainly has three steps, including detecting group structure based on random walks, extracting similarity features, and inferring group similarity using probabilistic graphical model. We evaluate our algorithm on five different types of online social networks. Experimental results show that our method achieves 0.693, 0.779, 0.729 in precision, recall, and ${F}1$ -measure, which significantly surpass the state-of-the-art by 31.4%–44.3%, 17.3%–26.3%, and 25.9%–31.6%, respectively. The outstanding performance of our method demonstrates that our proposal can reach the requirement of detecting similar groups across social networks. In particular, the result of this paper paves the way for the recommendation system, link prediction and information diffusion across sites.
A data mining based algorithm for traffic network flow forecasting

Recent development in ITS (Intelligent Transportation Systems) methods and technologies has moved traffic operating systems from passive to pro-active control and management, where real-time and accurate traffic flow information is critical to actual implementation. So far many algorithms have been proposed for traffic network flow forecasting, but problems in accuracy and timeliness still remain to be the major obstacle for their successful applications. For example, presumed human travel habit and vehicle turning probabilities at intersections have greatly limited the use of dynamic assignment algorithm. In order to improve the forecasting and real-time responsiveness, a new algorithm based on data mining which can do association rules mining and association analysis is proposed here for predicting traffic network flow. Simulation results using Corsim 5.0 have demonstrated effectiveness of the new algorithm in both accuracy and timeliness.
VIIRS ocean color products: A progress update

In this paper, we provide overview of the progress on the evaluations of the Visible Infrared Imaging Radiometer Suite (VIIRS) ocean color products with long-term time series and more in situ data for matchup analysis. Specifically, VIIRS ocean color products include normalized water-leaving radiance spectra nLw(λ) at VIIRS five spectral bands, chlorophyll-a concentration (Chl-a), water diffuse attenuation coefficients at the wavelength of 490 nm, Kd(490), and at the domain of photosynthetically available radiation (PAR), Kd(PAR). VIIRS ocean color products derived from the NOAA Multi-Sensor Level-1 to Level-2 (MSL12) ocean color data processing system are evaluated and compared routinely with in situ data from the Marine Optical Buoy (MOBY) and several AERONET-OC sites. In order to meet requirements from all users, we propose to routinely produce two ocean color data streams, i.e., the near-real-time (NRT) data and delayed science quality data. The NRT ocean color data stream has the advantage of quick data turn around with data latency -12-24 hours, while the science quality data stream has high consistence (with the mission-long data reprocessing) and accuracy of ocean color products. In addition, we have significantly improved on-orbit sensor calibration by combining the lunar calibration into the current solar calibration method. Our results show that VIIRS is now providing high-quality global ocean color products in support of the scientific research and operational applications.
Design on permanent magnet actuator and simulation of dynamic characteristic for vacuum circuit breaker

A novel Permanent Magnet Actuator (PMA) is put forward in this paper. The 3D magnetic distributions of PMA in different conditions have been computed, adopting ANSOFT9.0 software. In order to determine the size of each part of PMA, the variations of each parameter haw been simulated in dynamic course of breaking and closing. Based on the simulation results, the prototype is manufactured and assembled. The feasibility of the proposed PMA and the simulation veracity of the dynamic characteristic of breaking and closing hare been proved by the tested data of the prototype.
Demonstration of narrow-band acoustooptic tunable filters on dispersion-enhanced single-mode fibers

The physical parameters affecting the bandwidth of acoustooptic tunable filter on single-mode (SM) fiber are investigated. Compared to standard step-index SM fiber, we found that the bandwidth-length product can be reduced by a factor of 1.3 and 4 for nonzero-dispersion-shifted and dispersion-compensating fibers (DCFs), respectively. Record narrow bandwidth of 0.4 nm is measured for a 28-cm-long DCF (D of - 100 ps/nm/km at 1550 nm). The measured results are in good agreement with calculated values.
Analysis on Available Capability of Accommodating Wind Power in Shandong Power Grid

Status of wind power's development and accommodation is introduced in Shandong power grid. Available capability of accommodating wind power in spring of 2013 is analyzed under the condition of load, power interchange, generation and power grid prediction. Based on wind power prediction, actual wind power accommodation capability is carried out through wind power restriction caused by constraint of power transfer and peak-load regulation. Finally, the corresponding countermeasures are proposed in aspects of technology, management and planning according to the actual condition of Shandong power grid.
Continuous-wave terahertz digital holography of 3THz quantum cascade laser

Continuous-wave terahertz digital holography system has been established using 3THz quantum cascade laser. Holograms with no object located in the object beam path are recorded sequentially in air and vacuum conditions. Comparison between the two holograms illustrates that hologram retrieved in vacuum exhibits high quality and contrast. Besides, characteristic parameters of the laser beam focused and collimated in the system are interpreted in detail as well.
Wavelength and power dependence of injected C-band laser on pump conversion efficiency of L-band EDFA

The effect of wavelength and power of an injected C-band laser on the pump conversion efficiency of a L-band erbium-doped fiber amplifier was studied via numerical simulation and experiment. In the studied C-band wavelength range of 1530-1560 nm, for higher injected power with longer wavelength, the backward output amplified spontaneous emission power is compressed more; but the residual laser power is greater due to the smaller emission coefficient at longer wavelength. Thus there is a best choice for injection wavelength and power. With an injection of -2 dBm at 1550 nm, 4.3 and 2.5 dB of gain enhancement for -12 and -2.6 dBm input at 1586 nm were achieved, respectively.
Boosted deformable model for human body alignment

This paper studies image alignment, the problem of learning a shape and appearance model from labeled data and efficiently fitting the model to a non-rigid object with large variations. Given a set of images with manually labeled landmarks, our model representation consists of a shape component represented by a point distribution model and an appearance component represented by a collection of local features, trained discriminatively as a two-class classifier using boosting. Images with ground truth landmarks are the positive training samples while those with perturbed landmarks are considered as negatives. Enabled by piece-wise affine warping, corresponding local feature positions across all training samples form a hypothesis space for boosting. Image alignment is performed by maximizing the boosted classifier score, which is our distance measure, through iteratively mapping the feature positions to the image, and computing the gradient direction of the score with respect to the shape parameter. We apply this approach to human body alignment from surveillance-type images. We conduct experiments on the MIT pedestrian database where the body size is approximately 110 times 46 pixels, and demonstrate our real-time alignment capability.
Glitch-Free Multi-Modulus Frequency Divider for Quantization Noise suppression in fractional-N PLLs

A novel frequency divider for Quantization Noise (QN) suppression in fractional-N phase-locked loops (PLLs) is presented in this paper. The proposed Multi-Modulus Frequency Divider (MMFD) utilizes a novel glitch-free divide-by-0.5/1/1.5/2 cell to reduce the frequency division step to 0.5 and the quantization noise induced by ΔΣ modulation is thus suppressed by additional 6dB. The circuit is designed and simulated in a 0.18µm CMOS process. The maximum input frequency is up to 3.8GHz across all variations of Process, supply Voltage and Temperature (PVT) and the current consumption is about 8mA from a 1.8V supply. Compared with other frequency dividers used for QN suppression, the proposed MMFD achieves 6dB QN suppression while consuming less power and operating at higher input frequency.
The design of push-broom scanning satellite antenna

This article presents the scanning mechanism of push-broom satellite antenna working at 140 GHz. Such kind of antenna can be applied into many areas, such as imaging, ocean surveillance and astronomical observation. The feeds are placed at the rotary focus with a spacing of 1.72 cm between two adjacent feeds, and the center distance from the feed to the reflector surface is 14.48 cm. Meanwhile, the reflector surface is created by the rotation of a parabola with four boundaries, which is obtained by MATLAB program. Commercial software GRASP based on Physical Optics (PO) is employed to assess the performance of antenna. The simulation results of the far-field are obtained by the superposition field of each feed, which are plotted in the same output coordinate system.
Closed-loop control of MBE growth for AlAs/GaAs distributed Bragg reflectors using in-situ pyrometric interferometry monitoring

Reproducible control of layer thickness and composition is crucial to the performance and ease of manufacturing of many optoelectronic devices including vertical cavity surface emitting lasers (VCSELs). To achieve this objective, it is highly desirable to develop a continuous in situ monitoring and control scheme during the epitaxial growth. Such a system will not only improve the run-to-run growth reproducibility, but also relax the stringent precision requirement for growth rates calibration. Pyrometric interferometry (PI) has previously been used for in situ monitoring and control of GaAs/AlAs/lnGaAs VCSELs growth during molecular beam epitaxy (MBE) with considerable success. Compared with reflectometry and ellipsometry, PI can readily be installed in most existing MBE systems with minimum retrofitting, and the detected signal is relatively insensitive to optical alignment and substrate wobbling during rotation. The schematic of the model-reference control system is shown. To control layer switching, both the simulated and the reference PI data are modeled as amplitude and phase-modulated (AM and PM) signals. A least-square fitting algorithm is employed to track (demodulate) the "phase (/spl theta/)" (measured in radian) of the signal, which is used as criteria for layer switching. The results show that a highly reproducible PI signal can be obtained without a precise knowledge of the growth rate. We conclude by discussing (i) possible approaches for incorporating real-time adaptive control techniques, (ii) the extension of the current control scheme to multiple wavelength monitoring, and (iii) the implication of these studies on the prospect of realizing an intelligent MBE growth system.
Investigation of Frequency-Selective Surfaces for a THz Gyromultiplier Output System

The recent development of some high-power THz vacuum electronic devices calls for the application of space filters such as frequency-selective surfaces (FSSs) and polarization dividers. This paper presents the comparative study of two types of FSSs for a THz gyromultiplier output system, one with high-pass characteristic while the other one with low-pass functionality. Both FSSs are designed, fabricated, and experimentally tested between 200 and 1600 GHz to verify their capability of separating the dual-frequency output from the gyromultiplier. The high-power operation capability of the FSSs is also characterized by taking both the corona discharge and volumetric breakdown into consideration at the frequencies of interest. Based on the comparative study of the performance, the fabrication challenge and the high-power capability between the two FSSs, a generalized conclusion is given regarding the choice of the FSSs for high-power THz application.
Ultra-broad-band AOTF based on cladding etched single-mode fiber

The etching effect on the bandwidth of acoustooptic coupling between core and cladding modes in a single-mode (SM) fiber was investigated experimentally and theoretically. It was found that when the fiber diameter is etched down to a critical value, extremely broadband acoustooptic tunable filter (AOTF) could be achieved. We demonstrated an ultra-broadband acoustooptic filter with -3-dB bandwidth of 362 nm and dynamic range of >14 dB, which is the broadest bandwidth of AOTF on SMF up to now. The results point to potential realization of a new class of high efficient, fast, all-fiber variable optical attenuator.
A Direct Image Contrast Enhancement Algorithm in the Wavelet Domain for Screening Mammograms

In breast cancer diagnosis, the radiologists mainly use their eyes to discern cancer when they screen the mammograms. However, in many cases, cancer is not easily detected by the eyes because of the bad imaging conditions. In order to improve the correct diagnosis rate of cancer, image-enhancement technology is often used to enhance the image and aid the radiologists. In this paper, we develop a new image-enhancement technology in the wavelet domain for radiologists to screen mammograms. The new image-enhancement algorithm has several advantages. First, the proposed image-enhancement technology modifies a multiscale measure which matches the human vision system and thus the enhanced images have better visual quality; second, the image enhancement is accomplished in the wavelet domain and thus it can save time if the image is compressed by wavelet transform based methods; third, the end users can adjust the enhancement by manipulating a single parameter. Experiments were performed on mammograms and the results are progressive.
Fusion of radar and AIS data

The AIS system that will be brought into effect can improve shipping security for its more accurate information of target position and target identification. On applying AIS making use of the fusion of radar and AIS data should be attached important to. A method of fusion of radar and AIS data is proposed in this paper. The membership degree, on which the adaptive correlation-detecting function is constructed, is calculated by fuzzy C-mean clustering algorithm. It has been shown by simulations that reliable associations of track-to-track could be achieved.
Learning-based ballistic breech face impression image matching

Ballistic images of a cartridge case or bullet carry distinct “fingerprints” of the firearm, which is the foundation of widely used forensic examination in criminal investigations. In recent years, prior work has explored the effectiveness of correlation-based approaches in matching ballistic imagery. However, most of these studies focused on highly controlled situations and used relatively simple image processing techniques, without leveraging supervised learning schemes. Toward improving the matching accuracy, especially on operational data, we propose a learning-based approach to compute the similarity between two ballistic images with breech face impressions. Specifically, after a global alignment between the reference and probe images, we unroll them into the polar coordinate for robust feature extraction and global registration. A gentleBoost-based learning scheme selects an optimal set of local cells, each constituting a weak classifier using the cross-correlation function. Experimental results and comparison with state-of-the-art methods on the NIST database and a new operational database, OFL, obtained from Michigan State Forensics Laboratory demonstrate the viability of our approach.