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Selecting an appropriate object transfer point can effectively improve human comfort in the process of human-robot object transfer. In this article, a human-robot handover system based on human behavior patterns is proposed. First, the arm joint torque model and the medium joint angle model were combined to establish the human comfort model, and a binary cost function was constructed to predict the object transfer points for human-robot object transfer. Skeleton and RGB-D information were fused to construct a discriminant model of intention transfer for human-robot object transfer. Then the accuracy of intent recognition was verified through transfer intention recognition experiment. A human-to-human handover experiment was designed to obtain the actual object transfer points based on the OpenPose skeleton recognition, and the Bonferroni method was used to verify the difference between the predicted object transfer points and the actual transfer points, which proved that the predicted object transfer point was consistent with the actual transfer point. Finally, the experiments of robot-to-human handover and human-to-robot handover were carried out. The results of multipoint comparison surveys showed that the model can predict object transfer points that conform to human handover habits and bring more natural and smooth transfer experiences to human interactors. [ABSTRACT FROM AUTHOR]

The vertical stability (VS) coil is a set of circle-shaped multilayer in-vessel coil that is arranged in the vacuum vessel. For International Thermonuclear Experimental Reactor (ITER) prototypical VS coil, to avoid the interference with other in-vessel components some small bending arcs are designed. They are the R600 S-shaped bending arc with the angle of 9.2°, the R600 W-shaped bending arc with the angle of 20.3°, 38.1°, 20.3°, and the R215 S-shaped bending arc with the angle of 53.6°. The forming parameters of these arcs are studied in the article. Given the fact of conductor rebound after bending, the key issues of forming the arcs are to determine the suitable wheel mold radius and rotation angle. With regard to the determination of wheel mold radius, the forming deformation states of conductor under different wheel mold radius are simulated. Then the conductor displacement data after rebound are extracted to acquire the conductor inner and outer arcs fitting equations and the corresponding conductor radii are obtained simultaneously. If the calculated conductor central radius is different with the target value, the wheel mold radius will be adjusted and new simulation is employed. The reiteration work is terminated until the target radius is obtained. Subsequently, the wheel mold radius obtained in the data fitting process is referenced to fabricate the matching wheel mold. And the forming experiment is launched to verify the feasibility of conductor bending based on the above wheel mold radius. As to the determination of wheel mold rotation angle, the bending simulation and data fitting are carried out first. Then the process is repeated continuously until the target bending angle is obtained. Finally, the obtained wheel mold rotation angle is assigned as the preliminary bending angle in the forming experiment. If the forming results fail to satisfy the angle requirement, the preliminary bending angle is adjusted slightly and the forming experiment is performed again until the target bending angle is achieved. In addition, wrinkles are found during the forming process for the R215 S-shaped arc. To deal with the wrinkle issue a series of forming technology are attempted, while nearly all of them seem to be not feasible. Finally, bushing is installed at the outer surface of conductor jacket to reinforce its strength and resist the buckling impact from magnesium oxide (MgO). The forming experiments indicate bushing technology successfully eliminates the large wrinkles on the jacket. [ABSTRACT FROM AUTHOR]

The R&D of the central solenoid model coil (CSMC) is preparatory toward the final fabrication of the Chinese fusion engineering test reactor central solenoid coil. CSMC is being designed and partly fabricated in the Institute of Plasma Physics, Chinese Academy of Sciences (ASIPP). During the process, new manufacturing technologies are developed and some design optimization is proposed. Based on the latest design update, a mechanical analysis is launched to verify whether or not the local components can withstand the shock of the complex loads at the CSMC's steady operation stage. The local components here referred to are the current lead joint and joggle. The current lead joint is the key component to transfer the current into coil modules. The joggle is designed to achieve the smooth transition between the different layers during the conductor winding process. The representative current lead joint and joggle are chosen for the mechanical analysis. The electromagnetic analysis is carried out first to calculate the magnetic field and electromagnetic force density by using the software ANSYS. Then, a one-fifth structural analysis model is built to analyze the stress state of the local components under the combination loads. Finally, the local components are evaluated based on the analytical design. [ABSTRACT FROM AUTHOR]

The vertical stability coil will be used in China Fusion Engineering Test Reactor (CFETR) to improve its control capability on plasma. In view of the severe operation environment and high reliable requirement, it is a challenge for the coil to keep reliability during the whole lifetime, considering the prominent advantages of induction brazing, which is proposed for the coil joint connection. According to the electromagnetic-thermal coupling theory, the induction brazing simulation is carried out under different induction coil parameters. And a set of relatively reasonable induction coil parameter is obtained based on the average temperature and standard deviation of copper sample. In order to verify the brazing performance of the determined induction coil, the brazing experiment is launched with different joint structures and the brazing inspection is performed subsequently. Although it seems some joint design have the advantage of minimizing the damage on the outer magnesium oxide insulation layer, while they fail to satisfy the strength requirement. Based on the lessons, a new joint with thin external sleeve is designed and a series of performance tests are employed. It indicates that there is no large temperature gradient in the joint radial direction and the joint strength is prominently improved. [ABSTRACT FROM AUTHOR]

To bridge the data gap between Ice, Cloud, and land Elevation Satellite (ICESat) and the delayed forthcoming ICESat-2, the National Aeronautics and Space Administration has launched the Operation IceBridge (OI) campaign in 2009, which has provided variable data set to reveal snow and ice changes in the Arctic and Antarctic. In this letter, we employ the Airborne Topographic Mapper (ATM) data from OI to detect a five-year (between 2010 and 2015) elevation-change rate of Jakobshavn Isbrae (JI), the largest and fastest flowing outlet glacier in Greenland. Grid elevation of OI ATM is calculated and a method to calculate elevation-change rate using these grid data is implemented. The comparison of repeat grid elevation indicates that our method can generate unbiased elevation data. The uncertainty of grid elevation data using our method is approximately 1.0 m (standard deviation). The five-year average elevation rate of JI over regions with ice velocity ≥300 m/a between 2010 and 2015 was about −5.0 m/a (root mean square uncertainty: 0.7 m/a), with a maximum thinning rate of −18.2 m/a near the terminus of the main trunk. Compared with the previously reported elevation-change rates from earlier periods, JI has now reached a new high thinning record. [ABSTRACT FROM AUTHOR]

The central solenoid model coil of China Fusion Engineering Test Reactor consists of two modules: 1) the inner module made of Nb3Sn and 2) the outer module made of NbTi. This paper describes an optimization procedure for the electromagnetic design of the model coil by means of a Fortran code written for this purpose. The target of the optimization was the reduction of the length of the Nb3Sn cable-in-conduit conductor, needed to produce a peak magnetic field of 12 T. The optimization constraints are: 1) the maximum magnetic field on the NbTi module should be lower than 6 T and 2) the unit length of one Nb3Sn conductor should be shorter than 1 km. Based on the electromagnetic optimization, the engineering scheme of the model coil is determined. The feasibility of the engineering scheme is investigated using ANSYS finite element code. Accordingly, a mechanical analysis of the structure under the Lorentz force at 4.5 K is performed. The analysis results indicate that the present design is reasonable and fulfills the design requirements. [ABSTRACT FROM AUTHOR]

The Thematic Mapper onboard Landsat 4, 5, and Enhanced Thematic Mapper Plus (\textTM/ETM+) onboard Landsat 7 have frequency bands (green and SWIR) to effectively measure water body extents and their changes via the Modified Normalized Difference Water Index (MNDWI). Here, we developed a technique, called the thematic imagery-altimetry system (TIAS), to infer the vertical water changes from MNDWI horizontal water extent changes by integrating long-term \textTM/ETM+ imageries with available digital elevation models (DEMs). The result is a technique to quantify water level changes of natural or artificial water bodies over two decades. Several DEMs were used to compute intersects with \textTM/ETM+ water extent time series to evaluate the robustness of the technique. These DEMs include: the Advanced Spaceborne Thermal Emission and Reflection Radiometer Global Digital Elevation Map version 2 (ASTER-GDEM2, at 1 arcsec resolution), the Shuttle Radar Topography Mission version 2 (SRTM C-band at 1 arcsec), and the Global Multiresolution Terrain Elevation Data (GMTED2010 at 7.5 arcsec). We demonstrated our technique near Hoover Dam (HD) in Lake Mead to quantify its respective decadal water level changes. The dammed water had experienced extraordinary level variation in the past 20 years due to natural decline from intake or artificial impoundments. The discrepancy of the HD water level changes from an analysis of 32-year (1984–2015) time series, including 584 Landsat scenes, using the GMTED2010 DEM, has a RMSE reached 0.85 \pm 0.63\; \textm (91% of data) as compared with in situ stage record. [ABSTRACT FROM PUBLISHER]

A high-power photovoltaic (PV) system based on dual-stage topology of boost converter plus paralleled four-leg inverter is presented, which can perform as both grid-connected inverter and active power filter. The system not only can allow a wide range of input voltage from PV arrays, but also can compensate the nonlinear and unbalanced load current. This paper first presents the small-signal model of the presented inverter with LCL filter in d–q–o coordinate; then, the unified control strategy which combines PV power injection and distortional current compensation is demonstrated; finally, a method to control the zero-sequence circulating current between paralleled inverters is proposed. Simulations and experimental results are carried out on a 100-kVA prototype to validate the practicability of the whole system. [ABSTRACT FROM PUBLISHER]

To provide high-quality data for time-series change detection of lake water level, an automatic and robust algorithm for lake water footprint (LWF) identification is developed. Based on the Ice, Cloud, and Land Elevation Satellite GLA14 data file, six parameters were taken as features of an algorithm for LWF identification, and they are elevation difference between adjacent footprints, waveform width, number of peaks, reflectivity, kurtosis, and skewness of laser echoes. The sensitivity of each parameter was discussed, and elevation difference between adjacent footprints was proved to be most effective. The algorithm was described as a combination of these six parameters, and the thresholds of each parameter were set through statistics of LWF covering Peiku Co in Tibet, China, from 2003 to 2009. The performance of this classification algorithm was evaluated by the user's accuracy and producer's accuracy. Greater than 94% is achieved for all four tested lakes with 97% being the best result of producer's accuracy, and the user's accuracy ranges from 97.9% to 90% for these four lakes. [ABSTRACT FROM PUBLISHER]

The magnetocaloric and electrical properties in annealed Si-doped Ni48Mn39In13-xSix Heusler alloy ribbons with x=0–3 have been investigated. These ribbons crystallize in a partially ordered B2 phase structure. It was observed that both the martensitic structural transition TM and the Curie temperature TC of austenitic phase decrease with increasing Si contents. The small amount of Si in the In position modifies the peak value of positive magnetic entropy change \Delta SM for a magnetic field change H=50\ kOe, which vary from 20.2 J\cdot kg^-1\cdotK^-1 for x=0 to 23.1 J\cdot kg^-1\cdotK^-1 for x=1, and then decrease to 10.1 J\cdot kg^-1\cdotK^-1 for x=3. Meanwhile, the magnetoresistance associated with the martensitic transformation was found to be -45% for x=2 at T=192\ K for a magnetic field change of 50 kOe. [ABSTRACT FROM AUTHOR]