In situ Resource Utilization (ISRU) facilitates planetary exploration by drawing needed resources, such as water, from the local environment. However, the extreme nature of these environments require the development o...
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This paper presented a method of growing metallic nanowires by using electron beam technology under scanning electron microscopy (SEM). The metallic nanoparticles were dispersed evenly on Indium-Tin Oxide (ITO) by the...
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This paper presented a method of growing metallic nanowires by using electron beam technology under scanning electron microscopy (SEM). The metallic nanoparticles were dispersed evenly on Indium-Tin Oxide (ITO) by the spin coater. The ITO sample was experimentally prepared by the spin coating technique. The electron beam was focused on a metallic nano particle inside SEM, which were dispersed on the ITO. The growth of metallic nanowires was controlled by the movement of the electron beam. The method this paper presented can be employed for different kinds of metallic and can be used to fabricate metallic nanowires with different length.
This paper addresses the problem of driving an underwater vehicle to a desired position while optimizing the performance of a single-range based localization system. Indeed, the performance of single-range based local...
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This paper addresses the problem of driving an underwater vehicle to a desired position while optimizing the performance of a single-range based localization system. Indeed, the performance of single-range based localization techniques is strongly dependent on the vehicle's motion that needs to be sufficiently rich to yield a good measure of observability. We present a prioritized task oriented technique to combine a point-to-point guidance task with an observability optimization task. In particular, the minimum singular value of the Fisher Information Matrix is adopted as the observability metric. Task prioritization is achieved through a null-space-based projection technique that is also combined with a saturation management algorithm to cope with velocity command saturations. The stability of the resulting control law is analysed following a Lyapunov-based approach. Robustness against uncertainty in the initial position of the vehicle is also handled resorting to a procedure that maximises the minimum (worst-case) observability metric. Numerical simulations are reported confirming the effectiveness of the proposed strategy.
Gliomas are the most common primary brain malignancies, with different degrees of aggressiveness, variable prognosis and various heterogeneous histologic sub-regions, i.e., peritumoral edematous/invaded tissue, necrot...
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Motivation Here, we make available a second version of the BioTIME database, which compiles records of abundance estimates for species in sample events of ecological assemblages through time. The updated version expan...
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Motivation Here, we make available a second version of the BioTIME database, which compiles records of abundance estimates for species in sample events of ecological assemblages through time. The updated version expands version 1.0 of the database by doubling the number of studies and includes substantial additional curation to the taxonomic accuracy of the records, as well as the metadata. Moreover, we now provide an R package (BioTIMEr) to facilitate use of the database. Main Types of Variables Included The database is composed of one main data table containing the abundance records and 11 metadata tables. The data are organised in a hierarchy of scales where 11,989,233 records are nested in 1,603,067 sample events, from 553,253 sampling locations, which are nested in 708 studies. A study is defined as a sampling methodology applied to an assemblage for a minimum of 2 years. Spatial Location and Grain Sampling locations in BioTIME are distributed across the planet, including marine, terrestrial and freshwater realms. Spatial grain size and extent vary across studies depending on sampling methodology. We recommend gridding of sampling locations into areas of consistent size. Time Period and Grain The earliest time series in BioTIME start in 1874, and the most recent records are from 2023. Temporal grain and duration vary across studies. We recommend doing sample-level rarefaction to ensure consistent sampling effort through time before calculating any diversity metric. Major Taxa and Level of Measurement The database includes any eukaryotic taxa, with a combined total of 56,400 taxa. Software Format csv and. SQL.
Development of novel high added value cellulose products requires improved understanding of interaction forces, which includes also the adhesion force, between cellulose surfaces. However, the interaction forces betwe...
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ISBN:
(纸本)9781509029464
Development of novel high added value cellulose products requires improved understanding of interaction forces, which includes also the adhesion force, between cellulose surfaces. However, the interaction forces between cellulose surfaces have not been adequately studied. In this paper, cellulose-cellulose adhesion force is studied by using a customized dual-probe atomic force microscope (AFM) with a cellulose colloidal probe. Two different types of cellulose membranes (CM) with cellulose concentration of 1.5% and 2% are used as test samples, and about ten thousand tests are repeated on each CM sample type. Adhesion force histograms are provided and they show a large difference between the two types of CM. The average adhesion force on CM 1.5% is approximately 10 times higher than that on CM 2%. On CM 1.5%, the adhesion forces concentrate on the range from 450nN to 650nN, whereas on CM 2% the force distribute from 50 to 75nN. The difference in the adhesion force on these two types of CM can be attributed to their difference in surface roughness and surface energy.
The tutor-tutee hand-in-hand teaching may be the most effective approach for a tutee to acquire new motor skills. Repetitive nature of such procedures in a group setting usually results in a high labour cost and time ...
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ISBN:
(纸本)9781509037636
The tutor-tutee hand-in-hand teaching may be the most effective approach for a tutee to acquire new motor skills. Repetitive nature of such procedures in a group setting usually results in a high labour cost and time inefficiency. Potential solution can be utilizing robotic platforms playing the role of tutors for demonstrating and transferring the required skills. This requires an appropriate guidance scheme to integrate the tutor's motor functionalities into the robot's control architecture. For instance, for hand-in-hand supervision of the writing task, the tutor's corrections can be applied when necessary, while a very compliant motion can be achieved if no errors are detected. Inspired by this behavior, we develop a teaching interface using a dual-arm robotic platform. In our setup, one arm is connected to the tutees arm providing guidance through a variable stiffness control approach, and the other to the tutor to capture the motion and to feedback the tutees performance in a haptic manner. The reference stiffness for the tutors arm stiffness is estimated in real-time and replicated by the tutees robotic arm. Comparative experiments have been carried out on a dual-arm Baxter robot. The results imply that the human tutor is able to intuitively transfer writing skills to the tutee and also show superior learning performance over over some conventional teaching by demonstration techniques.
This paper proposes a passivity-based nonlinear disturbance observer (DOB) design for a powered upper-limb robot control. The proposed DOB allows for the nonlinearities of the robot dynamics, whereas the typical DOB d...
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ISBN:
(纸本)9781467380270
This paper proposes a passivity-based nonlinear disturbance observer (DOB) design for a powered upper-limb robot control. The proposed DOB allows for the nonlinearities of the robot dynamics, whereas the typical DOB designs cannot. Moreover, by virtue of the passivity property, human operator and environmental interactions can be embedded in the control loop. As a DOB, the proposed approach has a disturbance observation property that makes the actual robot behave like a nominal model selected by the user. Performance analysis proposes a gain tuning rule. In experimental validation, actual powered upper-limb robot is used to perform unknown payload carrying applications.
Robotic odor source localization is a promising tool with numerous applications in safety, search and rescue, and environmental science. In this paper, we present an algorithm for odor source localization using multip...
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作者:
Cui, JianleiZhang, JianweiHe, XiaoqiaoYang, XinjunMei, XuesongWang, WenjunJiang, GedongWang, KedianYang, LijunXie, Hui1. State Key Laboratory for Manufacturing Systems Engineering
Xi’an Jiaotong University Xi’an 710049 People’s Republic of China 2. State Key Laboratory of Digital Manufacturing Equipment and Technology Huazhong University of Science and Technology Wuhan 430074 People’s Republic of China 3. State Key Laboratory of Surface Physics and Department of Physics Fudan University Shanghai 200433 People’s Republic of China 4. State Key Laboratory of Robotics and Systems Harbin Institute of Technology Harbin 150001 People’s Republic of China 5. Department of Architecture and Civil Engineering City University of Hong Kong Tat Chee Avenue Kowloon Hong Kong 6. Center for Advanced Structural Materials City University of Hong Kong Shenzhen Research Institute Shenzhen 518057 People’s Republic of China
As for the interesting new building blocks, the Ag nanowires (AgNWs) and single-walled carbon nanotubes (SWNTs) as the interesting new building blocks are viewed as the promising candidates for the next-generation int...
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As for the interesting new building blocks, the Ag nanowires (AgNWs) and single-walled carbon nanotubes (SWNTs) as the interesting new building blocks are viewed as the promising candidates for the next-generation interconnects due to their most remarkable electrical, thermal, optical, mechanical, and other properties. The axial nanowelding of head-to-head style and side-to-side style is relatively simulated with the molecular dynamics method. As for the head-to-head structural style, SWNTs will move toward the AgNWs and contact with the head of AgNWs. And, the part of the Ag nanowire may be subsequently encapsulated in SWNT with the core-filling Ag atom chain as the final atomic contact configuration during nanowelding, which is related to the nanowelding temperature. When the SWNTs and AgNWs are arranged by the side-to-side contact style, the SWNTs will move along the SWNT surface and may eventually catch up with the AgNW being neck and neck. Aiming at the final axial atomic configurations and the contact behavior during nanowelding process, the related dominant mechanism is revealed in this paper.
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