nils-herrmann/clean_scirepeval huggingface dataset:
Joint resistance measurement using current-comparator for superconducting wires in high magnetic field

To assess the joint resistance between superconducting multifilamentary wires in a magnetic field, a measurement system using a current comparator has been developed for measuring the current decay induced in a superconducting loop containing a joint. It can measure both joint resistance and joint current carrying capacity up to 3000 A in a maximum magnetic field of 6.6 T. The joint resistances between superconducting wires soldered by diffusion welding and cold-pressing welding methods have been measured. The joint performance in magnetic fields of up to 6 T has been recorded.
Notice of RetractionAssessment of Time-Dependent Elastance of Superficial Arterial Wall by an External Vibration Stimulation

The aim of the study was to propose an external vibration method for measuring the time-dependent elastance of the arterial wall, an arterial stiffness indicator. A minute sinusoidal displacement with a frequency range from 50 to 100 Hz was used to impose on a superficial radial artery. At maximum amplitude of the sinusoidal displacement, the ratio of the reactive force from the radial wall and the maximum amplitude was inversely proportional to squared angular frequency of the sinusoidal displacement. Furthermore, the wall elastance could be determined from the relationship between the ratio of (reactive force / displacement) and the squared angular frequency. In twenty healthy subjects, the amplitude of the radial wall elastance was found to be a function of time or arterial blood pressure either at the room temperature or just after 5-minute cold stress. In addition, maximum of the time varying wall elastance within a cardiac cycle was significantly greater merely after the cold stress than at the room temperature (5.82±2.24 × 105 versus 3.86±1.26 × 105 dyne/cm, (p<;0.001). Briefly, the proposed method can be applied to obtain the time varying wall elastance of a superficial artery, and a 5-minute cold stress not only elevates the amplitude of wall elastance but also augments its dynamic range in a heartbeat period.
Development of a 10 kA HTS DC Power Cable

The new energy revolution which will be dominated by renewable energy will need to develop a corresponding new power grid. Based on the characteristics of renewable energy resources, and the stability problem of AC network, it was proposed that the DC-based transmission grid should be developed in the future. The high Tc Superconducting (HTS) power cable will be a competitive candidate for large-capacity power transmission of renewable energy. In this paper, the progress of the development of a 360 m/10 kA HTS DC power cable is presented, and the prospects of HTS cable is discussed.
Health care platform based on acquisition of ECG for HRV analysis

In the measurement of physiological signals, the electro-cardiogram (ECG) is essential to most medical diagnoses related to the heart behavior, which is closely associated with human's health. In this study, we have developed a health care platform (HCP) which is able to solve the baseline drift problem, detect the heart-rate status, and record the ECG signals. The HCP provides a convenient handheld device to collect ECG signals in moving state from only two conductive electrodes. The device transmits the data to computers through wireless transmission and shows real-time user's status including spectrum analysis and Fourier transform. In this paper, the HRV analysis is divided into two parts, one is time-domain analysis in HCP and frequency-domain analysis in PC. The experimental results analyze the life-behavior patterns of tested subjects that may affect HRV parameters (HF, LF and HF/LF) so that one may achieve the task of disease prevention and health management.
Performance Observations on MAC Protocols of VANETs in Intelligent Transportation System

In the vehicle communication system based on ADHOC network, besides fairness, QoS, hidden and exposed terminal problems, the MAC protocol must fulfill the requirement of practical applications. In order to decrease the transmission collisions in VANETs, a reliable and efficient medium access control (MAC) protocol is needed. Firstly, this paper introduces the applications, the characteristics of VANETs, and the difficulties of MAC protocols in VANETs. Secondly, based on different reactive routing protocols, various MAC protocols (wireless LAN and Adhoc MAC) applied to VANETs are theoretically compared and analyzed for sub-urban, urban, and freeway situations. A qualitative comparison of VANETs MAC protocols were given. Finally, the goals and the design essentials of transmission control in VANET are proposed.
Investigation on Failure Mechanisms of GaN HEMT Caused by High-Power Microwave (HPM) Pulses

This study aims at studying thermal and stress breakdown of gallium nitride (GaN) high-electron-mobility transistors (HEMTs) with a high-power microwave (HPM) pulse injected. A thermal breakdown model, depending on its pulse width and duty cycle, is proposed at first, and an equation is derived for calculating power threshold when both geometrical and material parameters of transistor are known. A series of GaN HEMT-based power amplifiers is designed and measured by using one special HPM system for characterizing their power-to-failure values, and the calculated ones are then fitted for further determining failure temperature of GaN HEMT. Further, electrothermal simulation is performed for capturing temperature and stress distributions over the structure, where a few correlations are observed between the simulated and calculated results. Finally, the crack area in the field plate of GaN HEMT is also characterized experimentally.
Room-temperature TiOx oxide diode for 1D1R resistance-switching memory

Resistive-switching behaviors in transition metal oxides, such as NiO and TiO2, have attracted great attention recently due to the potential for the next-generation nonvolatile memory applications [1, 2]. However, read disturbance due to the cross-talk among neighboring cells is a serious issue for the implementation of large memory array as shown in Fig. 1 . Traditionally, a transistor can be added as a selection element in the memory cell, the so-called 1T1R (one transistor one resistor) cell, to prevent undesirable cross-talk, but at the expense of increasing cell size and high thermal-budget. Nevertheless, it is unfavorable in the high-density memory array where the unit cell size and the low-temperature three-dimensional stacking is of the concern. Recently, a compact 1D1R cell, which utilizes an oxide-based diode as the selection element to cut off the parasitic cross-talk, has been realized [4]. The ratifying pn junction formed by two different oxide layers, one n-type and one p-type, provides sufficient on-off ratio and current density, but the high turn-on voltage and high ideality factor are less than ideal. In this study, we demonstrate a high forward-current TiOx diode fabricated at room temperature by a very simple process. Finally, the switching behavior of the 1D1R cell will be discussed.
The effect of H2 treatment on heterojunction with intrinsic thin layer (HIT) solar cell perfromance using 40.68MHz VHF-PECVD system

In this report, we studied the fabrication of heterojunction with intrinsic thin layer (HIT) solar cell, which was deposited by using very high frequency chemical vapor deposition (VHF-PECVD), at a high deposition rate under a low process temperature. The HIT solar cell has a very thin emitter layer on the light-incident surface (about 10nm) and the contact region was passivated by hydrogen (H2) plasma treatment to improve solar cell performance. With the passivation, the carrier transport may be enhanced and the extraction of photo current may also be increased. These features can make the Si-bulk absorbs more photons and extract more photo-electric current .
Vehicle Parking Guidance for Wireless Charge Using GMR Sensors

Implementation of a multifunctional contactless bidirectional charging and discharging system with the aid of giant magnetoresistance (GMR) effect for car parking guidance is proposed. Traditional Hall effect sensors can detect magnetic flux changes. However, if the changes are not significant enough to induce detectable interference voltage, there will be error detection. To remedy, a GMR sensor may detect tiny changes in the magnetic field, which will produce a larger change in resistance; this resistance is less susceptible to external noise influence while generating a relatively stable signal level. As a novel application, our research task combines a GMR sensor, a flexible magnetic stripe constituted by GMRs, a microprocessor and a wireless inductive power/data transfer module to realize a positioning control system for the parking lot's microgrid. Real-world experiments are conducted to verify the proposed approach.
Spectral error correcting output codes for efficient multiclass recognition

The error correcting output codes (ECOC) is a general framework to extend any binary classifier to the multiclass case. Finding the optimal ECOC is known as a NP hard problem. In this paper, we present a spectral analysis approach for the design of ECOC. We construct a similarity graph of the classes and generate ECOC with a subset of thresholded eigenvectors of the graph Laplacian. Using the spectral analysis, the coding efficiency, classifier's diversity, Hamming distance among codewords, and binary classifiers' accuracy can be simultaneously considered. The resulting ECOC is efficient, thus only a small set of binary classifiers are to be evaluated when making a decision. In experiments with large multiclass problems, our method is between 3 and 12 times faster comparing to one-against-all, with comparable classification accuracy. Our method also shows a better performance than the most of leading methods, e.g., ClassMap, random dense ECOC, random sparse ECOC, and discriminant ECOC.
Research on the Conduction-Cooled YBCO Magnet for an MW Class Induction Heating System

High-efficiency high-temperature superconducting (HTS) induction heating equipment has been regarded as a promising application for thermal processing of metal material, in which an HTS magnet generates a high magnetic field to form the background field in the iron core and the rotating billet is heated by eddy current to process temperature. Efficiency analysis for the traditional induction heating and new structures for the HTS induction heating are studied in this paper. A new type of superconducting induction heating magnet structure is proposed. Through the parallel connection of multiple magnetic circuits, it can make more effective use of the high magnetic field produced by superconducting magnets. The applicable range and application criterion of the new structure are also given. Calculation models for induction heating system electromagnetic field and billet region temperature field analysis are established. The megawatt (MW) class conduction-cooled Yttrium Barium Copper Oxide (YBCO) magnet system is designed. The magnet consists of an iron core and HTS coils wound with the spliced YBCO-coated conductors. The magnet system is cooled by two AL325 GM refrigerators and the operating temperature is 20 ∼ 30 K. Furthermore, the prototype YBCO coils with the same thickness are fabricated and tested in the LN2. Test result of the prototype magnet is presented.
Turn-on capability of 22 kV SiC Emitter Turn-off (ETO) Thyristor

The turn-on characteristics for the SiC p-ETO are researched in this paper. By establishing the two-dimensional numerical model of the SiC p-ETO, the influence of the device parameters and external circuit conditions on the turn-on speed is discussed. The experiments agree with the simulated results well. The npn turn-on mode of ETO is captured in a high di/dt experiment, which proves the existence of the FBSOA for this time hence the possibility of its application in converters without di/dt snubber. According to the intrinsic temperature limitation of the SiC material, the simulation shows that the peak power density of the SiC p-ETO during turn-on could reach several tens of MW/cm2.
A formal representation of the structural semantics of Domain-Specific Modeling Language

Domain-Specific Modeling has been widely and successfully used in system design and modeling of specific areas. Due to informal definition of Domain-Specific Modeling Language (DSML) and Meta-Modeling Language (DSMML), the structural semantics of DSMLs and DSMMLs cannot be strictly described and the properties based on it also cannot be systematically analyzed and validated. In response, the paper proposes a formal description method of the structural semantics of DSML and DSMML. Firstly, a formal definition of domain and meta-domain based on algebra is presented, secondly, a mapping mechanism from domain and meta-domain to the corresponding first-order logic system is established, based on this, the method of formalization of structural semantics of DSML based on first-order logic is presented, finally, the formalization automatic mapping engine is designed and relevant test is performed to show the feasibility of our formal method.
A new flywheel energy storage system using hybrid superconducting magnetic bearings

The high temperature superconductor (HTS) YBaCuO coupled with permanent magnets has been applied to construct the superconducting magnetic bearings (SMB) which can be utilized in some engineering fields such as the flywheel energy storage system (FESS). However, there are many problems needed to be resolved, such as low stiffness and damping, the uncertainty of working displacement, flux creep and flux flow. In this paper, a new FESS using hybrid SMB system which consists of SMB, active magnetic bearings (AMB), and permanent magnetic bearings (PMB) is presented. In this design, the authors constructed an experimental device for the FESS with hybrid SMB. An axial PMB is joined to provide a levitation force so as to suspend a heavier flywheel; in addition, two AMB are added in radial degrees to improve the stiffness by two orders of magnitude from 10/sup 4/ N/m to 10/sup 6/ N/m and the damping of FESS.
A Class-D amplifier powered by embedded single-inductor bipolar-output power module with low common noise and dynamic voltage boosting technique

This paper proposes a high efficiency Class-D amplifier (CDA) with embedded single-inductor bipolar output (SIBO) power module. The characteristics of SIBO converter's bipolar outputs not only suppress equivalent common mode noise but also remove several large external bulky components in conventional boost supply CDA systems. Since bipolar outputs in the SIBO provide independent driving capability, CDA is capable of operating in both single-ended (SE) and bridge-tide load (BTL) configurations. Furthermore, the proposed dynamic voltage boosting (DVB) technique adjusts the SIBO output voltage level according to the CDA's output level with 5% power efficiency improvement. Peak total harmonic distortion plus noise (THD+N) performance is 0.012%. Peak power efficiency of SIBO and CDA are 89% and 93.2%, respectively.
3D Sub-query Expansion for Improving Sketch-Based Multi-view Image Retrieval

We propose a 3D sub-query expansion approach for boosting sketch-based multi-view image retrieval. The core idea of our method is to automatically convert two (guided) 2D sketches into an approximated 3D sketch model, and then generate multi-view sketches as expanded sub-queries to improve the retrieval performance. To learn the weights among synthesized views (sub-queries), we present a new multi-query feature to model the similarity between sub-queries and dataset images, and formulate it into a convex optimization problem. Our approach shows superior performance compared with the state-of-the-art approach on a public multi-view image dataset. Moreover, we also conduct sensitivity tests to analyze the parameters of our approach based on the gathered user sketches.
Design and analysis of Bayesian game in role based trust management

Role based trust management is capable of handling the dynamicity and uncertainty of security in multi-domain distributed environment. The interactions between trust domains and users can be modeled as Bayesian games in which both players have their own strategies and payoffs. This paper shows how Game Theory can be a tool to analyze the behaviors of every player in role based trust framework. We describe the types of players and design the details of games. Considering two types of users - cooperative and malicious, we analyze the strategy sets and payoffs of trust domains and each type of users. The equilibriums of the game show how a trust domain can select proper strategies to maximize its total profits.
Timely and Quantitative Damage Assessment of Oyster Racks Using UAV Images

Oyster racks identification relies on manual in situ assessment and often leads to a compensation dispute in aquacultural damage assessment. This study proposes an efficient classification method to identify oyster racks using unmanned aerial vehiclesw (UAVs) images. After image preprocessed by the morphology-based opening operation and mosaicing, the Canny edge detection algorithm, an edge line reparation algorithm, and the multiresolution segmentation techniques are applied to recognize the boundary of oyster racks and the number of oyster racks are further obtained. In this study, a case study was carried out in the District 23 of Dongshi fishing port on September 4, 2015 and October 5, 2015 to evaluate the influence of the Typhoon Dujuan. Based on the image identification, eight horizontal racks were destroyed by the storm surges and strong winds, but the raft-string racks were increased by 60, which were steered from neighbor districts. The damaged ratio of oyster racks was successfully identified and 38 racks were eligible for disaster relief. Comparing to the current manual in situ damage assessment process taking over one month, the proposed process provides a timely and quantitative assessment by efficiently identifying oyster racks on the UAV images within one week, which demonstrated that the proposed process is a promising way for the efficient damage assessment of oyster racks.
Electrothermal Effects on Performance of GaAs HBT Power Amplifier During Power Versus Time (PVT) Variation at GSM/DCS Bands

Power versus time (PVT) variation is one of the most important features for describing electrothermal performance of RF power amplifiers (PAs) for global system for mobile communication/digital cellular system bands. The PA sometimes produces high power at the first time slot and low power at the second time slot, which results in similar temperature variation caused by its self-heating effect. Therefore, both theoretical and experimental investigations are carried out for capturing electrothermal effects on the performance of GaAs-based heterojunction bipolar transistor (HBT) PAs. The temperature distribution over the PA die is obtained using our in-house developed finite-element method algorithm and a thermal infrared scanner, respectively. In particular, the PVT variation of the PA for a two time slot, as well as a four time slot (i.e., 75% of its operation time is in the “power on” state) case is studied in detail. Furthermore, an improved design for the GaAs HBT PA chip is performed, fabricated, and tested with its PVT variation suppressed effectively. This study should be very useful for the development of PAs for many wireless communications.
Autonomous vehicle parking using artificial intelligent approach

This paper devotes to the design and implementation of a hybrid artificial intelligent control scheme for a car-like vehicle through the performance optimization of the task of car parking. The genetic algorithm is used to determine the feasible parking locations. The Petri-net is used to replace the traditional system flow chart and most importantly, to plan alternative parking routes especially in a global space. A fuzzy controller is utilized to drive the car along the optimal parking route.
Reinforcement learning with continuous vector output

A new reinforcement learning algorithm with continuous vector output (CVRL) is proposed for a continuous process with multiple-input and multiple-output. CVRL is a generic hierarchically structured framework. The lower layer is composed with several groups of action units and continuous vector output can be produced based on action combination. The higher layer is a Q-learning unit defined on the space of combined action, its responsibility is the selection of properly combined actions. A detailed implementation of the CVRL is given, and the simulation on a mobile robot navigation problem demonstrates its effectiveness.
BRAM efficient multi-ported memory on FPGA

Multi-ported memory is broadly used in modern designs on FPGAs. However, the excessive demand on BRAMs to implement multi-ported memory on FPGA would block the usage of BRAMs for other parts of a design. This issue becomes a serious concern especially for designs that require huge internal storage capacity. This paper proposes a BRAM efficient scheme on increasing read ports and write ports. When compared with previous works, the proposed multi-ported memory can reduce up to 53% requirement on BRAMs with only minor frequency degradation.
Segment an image by looking into an image corpus

This paper investigates how to segment an image into semantic regions by harnessing an unlabeled image corpus. First, the image segmentation task is recast as a small-size patch grouping problem. Then, we discover two novel patch-pair priors, namely the first-order patch-pair density prior and the second-order patch-pair co-occurrence prior, founded on two statistical observations from the natural image corpus. The underlying rationalities are: 1) a patch-pair falling within the same object region generally has higher density than a patch-pair falling on different objects, and 2) two patch-pairs with high co-occurrence frequency are likely to bear similar semantic consistence confidences (SCCs), i.e. the confidence of the consisted two patches belonging to the same semantic concept. These two discriminative priors are further integrated into a unified objective function in order to augment the intrinsic patch-pair similarities, originally calculated using patch-level visual features, into the semantic consistence confidences. Nonnegative constraint is also imposed over the output variables and an efficient iterative procedure is provided to seek the optimal solution. The ultimate patch grouping is conducted by first building a similarity graph, which takes the atomic patches as vertices and the augmented patch-pair SCCs as edge weights, and then employing the popular Normalized Cut approach to group patches into semantic clusters. Extensive image segmentation experiments on two public databases clearly demonstrate the superiority of the proposed approach over various state-of-the-arts unsupervised image segmentation algorithms.
Fish-Tail Modeling for Fish Robot

Derivation of the mathematical model for a robot fish considering forward motion and yaw angle kinematics is presented. This model also includes details of the hydrodynamic force by considering the condition of fish swimming underwater. The nonlinear dynamical model in Carangi form locomotion type is derived by use of Lagrange's equation, which concerning about 4 links of fish robot equivalent model similar to the 4-link planar robot manipulator. Computer simulations conduct both in terms of open-loop response and animation motion of the fish robot swimming. These results indicate feasibility of the model for the robot with swimming speed 0.48 m/s and yaw swing angle ±12 degree. The model derived will be served as a basis for further investigation of control design for the complicated object.