nils-herrmann/clean_scirepeval huggingface dataset:
Design of a reconfigurable dual-band mixer for IMT-A and UWB systems

This paper presents the design and analysis of a reconfigurable dual-band down-conversion mixer for IMT-Advanced (3.4~3.6 GHz) and UWB (4.2~4.8 GHz) applications. The proposed mixer is based on folded double-balanced Gilbert cell which is well-known for its low voltage, simplicity and well-balanced performances. The mixer adopts capacitive cross-coupling technique for input matching and performance improvement. Switched capacitors and resistors are added to shift the working bands. Designed in SMIC 0.13-µm process, the simulation results show flat conversion gains of 9.65 to 9.75 dB and 9.75 to 9.90 dB, single-sideband noise figures of 12.2 dB and 12.8 dB for IMT-Advanced and UWB applications, respectively. The input third-order intercept points are about 7.3 dBm for both of the frequency bands. The mixer core dissipates 4.8 mW under 1.2 V supply, and the total area of the layout is 0.76×0.65 mm2.
Differential detection acquisition in multiple-access time-hopping ultra-wideband communications

Differential detection acquisition (DDA) is a novel rapid acquisition approach proposed in Zhang et al. (2003) for the time-hopping (TH) sequence in ultra-wideband (UWB) wireless communications. This paper extends the approach to the multiple-access TH UWB system. Acquiring a TH sequence in the multiuser case is described. The acquisition probability and mean acquisition time are analyzed mathematically in detail. The computer simulation results are also given.
Biological Effects of Nanohydroxyapatite Materials and Its Toxicity

Biological effects of the nanohydroxyapatites materials and its toxicity have been studied using ultraviolet absorption spectrum, infrared spectrum of absorption and MTT method. The nanohydroxyapatites are prepared and made by using Sol-gel method, in which the parameters of process and reaction are controlled as: PH> 9, Ca / P = 1.67, sintering temperature of 11000C and sintering time 2 hours. Studied results show that nanohydroxyapatites can adsorb the amino acid molecules, the more stronger of acidity of amino acids, the more larger of ability of the absorption. Meanwhile we find that the nanohydroxyapatites and complex of nanoHAP+ nanoCrO2 can all restrain the proliferation of cells, but their toxicitis are all first degree or ninor, but the restrained effect of the latter is smaller than that of the former, although they can decrease the relative proliferation rate of cells . This is a new and interesting result.
Attribute Grid Computer based on Qualitative Mapping and its application in pattern Recognition

A new kind of Computer, called Attribute Grid Computer based on Qualitative Mapping is presented in this paper, It is shown that a series of intelligent methods, such as Production System, Artificial Neural Network, and Support Vector Machine can be fused in the framework of qualitative criterion transformation of qualitative mapping and can be implemented by attribute grid computer. And some examples of application in pattern recognition are given too.
Color Uniformity Enhancement for WLEDs Using Inverted Dispensing Method

The inverted dispensing (ID) method is proposed to fabricate remote phosphor layers (RPLs) with cone-like shapes for white light-emitting diodes (WLEDs) to improve their color uniformity. We introduce surface evolver packages and optical simulations to study the effect of the surface tension on the optical performance of these WLEDs during the ID process. The results show that a decreasing surface tension contributes to a sharpened geometry of the RPL. This sharpened surface geometry is responsible for the optimization of the color uniformity by deflecting blue light towards central angles. The proposed ID method is simple and efficient. The color uniformity performance can be tuned by selecting silicone with a proper surface tension without affecting the total correlated color temperature and sacrificing the WLED’s optical power.
A modified two-fluid model of turbid density current based on effective drag coefficient

The two phase numerical models applied for resolving turbid density current have developed recently, while the inter phase forces of the usual two-fluid model only include the viscous drag. Based on the analysis of the motion and forces of a small single particle (dp=0.01mm∼0.09mm) in the uniform flow field obtained from the dynamic equation, it was found that the proportion of the Basset force was 7.3%∼25.6%. Therefore it was necessary to include the Basset force in the usual two-fluid model when it was applied to simulate the turbid density current containing fine sediment. Here, the effective drag including the Basset force and the viscous drag was proposed, and the formulas of the effective drag coefficient CT was obtained which contained Reynolds number and Archimedes number. Then, the modified two-fluid model was applied to simulate the turbid density current in a glass tank. It showed that the maximum head thickness got from the modified model were more close to the experiment.
Nonnegative Matrix Factorization With Regularizations

Matrix factorization techniques have been frequently applied in many fields. Among them, nonnegative matrix factorization (NMF) has received considerable attention for it aims to find a parts-based, linear representations of nonnegative data. Recently, many researchers propose various manifold learning algorithms to enhance learning performance by considering the local manifold smoothness assumption. However, NMF does not consider the geometrical structure of data and the local manifold smoothness does not directly ensure the representations of the data point with different labels being dissimilar. In order to find a better representation of data, we propose a novel matrix decomposition method, called nonnegative matrix factorization with Regularizations (RNMF), which incorporates three appropriate regularizations: nonnegative matrix factorization, the local manifold smoothness and a rank constraint. The representations of data learned by RNMF tend to be discriminative and sparse. By learning a Mahalanobis distance space based on labeled data, RNMF can also be extended to a semi-supervised algorithm (semi-RNMF) which has an amazing improvement on clustering performance. Our empirical study shows encouraging results of the proposed algorithm in comparison to the state-of-the-art algorithms on real-world problems.
Improved transmit diversity block coded OFDM systems for highly dispersive channels

In 2000, King proposed two g/sub 2/-based transmit diversity block coded OFDM (TDBC-OFDM) systems, i.e., space-time block coded (STBC-OFDM) and space-frequency block coded OFDM (SFBC-OFDM). However, he employed the least square (LS) detector, which was designed under the assumption that the channel is static over the duration of a space-time/frequency codeword. Thereupon, STBC-OFDM/SFBC-OFDM suffers from highly time-frequency selectivity of the channel. Recently, Antony recommended three novel detectors for space-time block coding (STBC) to combat the rapid channel variation. In our work, these detectors are applied to improve the original g/sub 2/-based TDBC-OFDM systems. Also, the performances of the improved g/sub 2/-based TDBC-OFDM systems are evaluated by computer simulation. Simulation results have revealed that significant performance improvement can be achieved even when the systems are operated in highly dispersive channels.
Research on a novel method for improving inverter output waveforms

A novel method which can improve medium frequency inverter power supply output waveforms using Delta inverter compensate technology is put forward in this paper. Taking parallel compensation as an example, the theoretical analysis of Delta inverter's compensation principle is given. The novel method can improve inverter output waveform distortion which is caused by voltage source inverter's inherent factors like dead time. The simulation model is established based on MATLAB/Simulink, and the system is simulated. In this paper, the experimental equipment of medium frequency inverter compensating system using DSP is designed, and the main inverter and Delta compensating inverter control system is realized. The experimental results prove that Delta inverter as a compensation device can effectively improve the quality of main inverter output waveform, reduce greatly the output sinusoidal voltage waveform distortion and decrease the harmonics content.
Model of performance evaluation to electronic resources of University Library Consortia based on rough set

Electronic resource of university library is important academic resource. To realize the advantages of electronic resources and achieve a regional sharing of electronic resources, University Library Consortia has been established. A reasonable evaluation to performance of electronic resources is essential for promoting the utilization of university library electronic resources. Based on the method of rough set, a system of performance evaluation to electronic resource is set up, and performance of electronic resources is evaluated.
Exploring Weakly Labeled Images for Video Object Segmentation With Submodular Proposal Selection

Video object segmentation (VOS) is important for various computer vision problems, and handling it with minimal human supervision is highly desired for the large-scale applications. To bring down the supervision, existing approaches largely follow a data mining perspective by assuming the availability of multiple videos sharing the same object categories. It, however, would be problematic for the tasks that consume a single video. To address this problem, this paper proposes a novel approach that explores weakly labeled images to solve video object segmentation. Given a video labeled with a target category, images labeled with the same category are collected, from which noisy object exemplars are automatically discovered. After that the proposed approach extracts a set of region proposals on various frames and efficiently matches them with massive noisy exemplars in terms of appearance and spatial context. We then jointly select the best proposals across the video by solving a novel submodular problem that combines region voting and global region matching. Finally, the localization results are leveraged as strong supervision to guide pixel-level segmentation. Extensive experiments are conducted on two challenging public databases: Youtube-Objects and DAVIS. The results suggest that the proposed approach improves over previous weakly supervised/unsupervised approaches significantly, showing a performance even comparable with the several approaches supervised by the costly manual segmentations.
Retrieving High-Resolution Surface Soil Moisture by Downscaling AMSR-E Brightness Temperature Using MODIS LST and NDVI Data

A method to retrieve soil moisture at high spatial resolution is presented in this paper. The method is based on soil moisture retrieval with passive brightness temperature. The method of retrieving land surface temperature with passive microwave is combined with the relationship between the microwave polarization difference index (MPDI) and normalized difference of vegetation index (NDVI) to obtain high-resolution microwave brightness temperature and soil moisture. Advanced Microwave Scanning Radiometer-Earth Observing System (AMSR-E) 18.7-GHz brightness temperature at 25-km resolution is downscaled to 1-km using high-resolution MODIS visible/infrared (VIS/IR) data. High-resolution soil moisture is retrieved with the downscaled microwave brightness temperature using a single-channel algorithm (SCA) and the Qp model to deal with the influence of roughness. The method is applied to an area in northwest of China. The downscaled high-resolution soil moisture is tested with ground data collected at three sites within the Maqu monitoring network from July 1, 2008 to June 30, 2009. The trend of the time series of the downscaled soil moisture is similar to the ground measurements during this period with root mean-square error (RMSE) less than 0.12. The results show that the method is more suitable to moderate to drier soil conditions with bare surface or covered by sparse vegetation.
A robot arm/hand teleoperation system with telepresence and shared control

This paper describes a master-slave teleoperation system which is developed to evaluate the effectiveness of teleopresence in telerobotics applications. The operator wears a dataglove augmented with an arm-grounded force feedback device to control the dexterous hand and utilizes a spaceball to control robot arm. Contact forces measured by the finger sensors can be feedback to the operator and visual telepresence systems collect the remote operation scenes and display to the operator by a stereo helmet. A primitive autonomous grasp system based on parallel joint torque/position control is developed. The experimental results show that this teleoperation system is intuitive and productive and the primitive autonomous grasp is feasible and efficient
Multiresolution object-of-interest detection for images with low depth of field

This paper describes a novel multiresolution image segmentation algorithm for separating sharply focused objects-of-interest from other foreground or background objects in low depth-of-field (DOF) images, such as sports, telephoto, macro, and microscopic images. The algorithm takes a multiscale context-dependent approach to segment images based on features extracted from wavelet coefficients in high-frequency bands. The algorithm is fully automatic in that all parameters are image-independent. Experiments with the algorithm on more than 100 low DOF images have shown results close to the human segmentation of these images. Besides high accuracy, the algorithm also provides high speed. A 768/spl times/512 pixel image can be segmented within two seconds on a Pentium Pro 300 MHz PC.
SAR raw data generation and image simulation of aircrafts on the runway

Because of complex scattering mechanism between the target and the runway, synthetic aperture radar (SAR) raw data generation and image simulation for the aircraft standing on the runway is a difficult thing. In this work, a new procedure is proposed to deal with this problem. Major scattered field from both the aircraft and the runway are calculated, meanwhile, multipath scattering and the shadowing between the aircraft and the runway are also considered explicitly. Simulating results demonstrate the validity and usefulness of the procedure.
Effect of Six Fungicides against Botrytis Cinerea on Protected Cultivation Tomato

Six fungicides are selected and used to control Botrytis Cinerea on tomato under protected cultivation. The fungicides include Fludioxonil, BoscaLid, Pyrimethanil (ISO, BSI), Diethofencarb, Carbendazim, Procymidone and Thiophanate-methyl. These Chemicals were sprayed three times and once a week before or in the beginning of disease development. The results show that all the six fungicides have different negative effect on the growing of Botrytis Cinerea. Two of them, 50% BoscaLid (750 g/hm2) and 50% Fludioxonil (750 g/hm2), have significantly inhibited more than 77% of disease development in leaves and fruits resulting in almost 4 times increase of yield compared with control. Other two Chemicals, 40% Pyrimethanil (1550 g/hm2) and 60% Diethofencarb-Carbendazim (1550 g/hm2) also reduced more than 49.35% of disease development in leaves and fruits resulting in 3 time increase of yield compared with control. The last two fungicides 50% Procymidone (1800 g/hm2) and 70% Thiophanate-methyl (2580 g/hm2) have less effect on Botrytis Cinerea.
Improved identification method of pulmonary elastance fuzzy model based on pre-adjustment of membership functions

In artificial respiration, setting of ventilation conditions is expected to fit each patient. Characteristics of people's respiratory systems are very different and those values are very difficult to be measured directly. The aim of our research is to establish a framework to modeling the respiratory system and to set appropriate ventilation conditions based on the characteristics estimation to fit individual patient. For this purpose, an iterative estimation method of fuzzy pulmonary elastance model has been proposed by authors in the previous works. In this paper, an improved identification method is addressed in which an optimal pre-adjustment procedure of membership functions of fuzzy variables is incorporated in the iterative estimation method. A numerical example based on real clinical data is shown to illustrate the improvement in proposed algorithm.
Integrating GIS with Cellular Automaton Model for Railway Transportation Safety System

The railway transportation safety system is a complex dynamic system with spatio-temporal characteristics. However, currently commercial Geographical Information System (GIS) lacks these capabilities for spatio-temporal analysis and modeling. Cellular automaton (CA) model can provides GIS with a bottom-to-top spatio-temporal modeling frame. The simplicity and flexibility make CA able to simulate a variety of behaviors of complex systems. In order to meet the needs of spatio-temporal simulation of the railway transportation safety system, we propose a new CA model -- a Safety System Model for Railway (SSM-R) -- to simulate the railway safety and put forward the integrated GIS and CA framework. Based on the integration method, a simulation experiment is carried out with ArcGIS Engine 9.1 and Dot Net. The results show that the model can interpret the evolutional law of the railway transportation safety system and GIS-CA integration can simulate realistic railway transportation safety system.
Homoepitaxial Growth and Device Characteristics of SiC on Off-Oriented Si-Face (0001) 4H-SiC

Homoepitaxial growth of unintentional doped, nitrogen (N) doped n-type, and boron (B) doped p-type 4H-SiC epilayers on off-oriented n-type and semi-insulating Si-face (0001) substrates was performed in a horizontal hot-wall chemical vapor deposition (HW-CVD) reactor with SiH 4 and C2H4 at temperature of 1500 degC and pressure of 40 Torr. The electrical and structural properties, and intentional in-situ doping in 4H-SiC epilayers were investigated by using room temperature Hall effect measurement, Raman scattering measurement, and secondary ion mass spectroscopy (SIMS). PiN and MESFET structural materials were obtained by growing B-doped and undoped 4H-SiC epitaxial layers on n-type substrates and N-doped and undoped on semi-insulating substrates, respectively. The I-V characteristics of high power PiN rectifiers, UV PiN detectors and MESFETs were presented
An efficient clustering algorithm

Clustering analysis plays an important role in scientific research and commercial application. K-means algorithm is a widely used partition method in clustering. As the dataset's scale increases rapidly, it is difficult to use K-means and deal with massive data. An improved K-means algorithm is presented. It can avoid getting into locally optimal solution in some degree, and reduce the probability of dividing one big cluster into two or more ones owing to the adoption of squared-error criterion. The experiments demonstrate that the improved K-means is more stable and more accurate.
Fuzzy Dynamic Petri Nets

Fuzzy dynamic Petri nets model is proposed to process systems with vague information. Different from the traditional fuzzy Petri net systems, we address the Petri nets in the concept of net framework, instead of just a logical prediction system. Formal definition of dynamic Petri nets and its relation matrix description are given. Then, based-on the relation matrix, fuzzy dynamic algorithm is proposed to study the dynamic process. The feasibility and validity of the proposed approach are illustrated through a diagnosis expert system.
Automatic Design of Color Filter Arrays in the Frequency Domain.

In digital color imaging, the raw image is typically obtained through a single sensor covered by a color filter array (CFA), which allows only one color component to be measured at each pixel. The procedure to reconstruct a full color image from the raw image is known as demosaicking. Since the CFA may cause irreversible visual artifacts, the CFA and the demosaicking algorithm are crucial to the quality of demosaicked images. Fortunately, the design of CFAs in the frequency domain provides a theoretical approach to handling this issue. However, almost all the existing design methods in the frequency domain involve considerable human effort. In this paper, we present a new method to automatically design CFAs in the frequency domain. Our method is based on the frequency structure representation of mosaicked images. We utilize a multi-objective optimization approach to propose frequency structure candidates, in which the overlap among the frequency components of images mosaicked with the CFA is minimized. Then, we optimize parameters for each candidate, which is formulated as a constrained optimization problem. We use the alternating direction method to solve it. Our parameter optimization method is applicable to arbitrary frequency structures, including those with conjugate replicas of chrominance components. Experiments on benchmark images confirm the advantage of the proposed method.
Quasi-constant envelope OQPSK through nonlinear radio and AWGN channel

A quasi-constant envelope OQPSK (QCEOQPSK) signal is formed using a linear OQPSK modulator to overcome the nonlinearity caused by fully saturated RF power amplifiers. The performance of the QCEOQPSK signal in a AWGN channel is studied for a variety of filters in the transmitter and matched linear filters followed by hard decision in the demodulator. It is shown that at -43 dB the mainlobe of the power spectral density of the QCEOQPSK is only 77% of the bandwidth corresponding to the mainlobe of the MSK power spectrum density. At a bit error rate of 10/sup -5/, the SNR degradation caused by fully saturated power amplifiers is 0.1 dB in the AWGN channel compared with the ideal BER of BPSK using linear power amplifier. This is 2.3 dB better than the bit error rate of QPSK using linear power amplifier in the broadband satellite communications systems. Employing rate 1/2 convolutional code with constraint length K = 6 and the Viterbi (1966) decoder, the SNR degradation is only 0.25 dB at BER = 10/sup -5/. Therefore, QCEOQPSK can be employed in broadband wireless or broadband satellite communication systems to achieve higher spectral efficiency, near optimal demodulation performance and significantly reduce terminal cost.