Abstract: The present application presents novel systems and methods for tracking reinforcement member placement in an additively manufactured structure that are simple, accurate, non-labor-intensive, and cost-effective. The present application also presents a novel method of manufacturing a tower structure comprising: depositing, via an additive printing system, a first printed layer of a wall with a printhead assembly, the wall at least partially circumscribing a vertical axis of the tower structure; positioning a first reinforcement member on the first printed layer; depositing, via the additive printing system, a second printed layer of the wall with the printhead assembly on the first reinforcement member, the second printed layer configured to hold a second reinforcement member thereon; and determining, via an optical sensor of the additive printing system, a position for placing the second reinforcement member based on the first reinforcement member positioning.

Abstract: A flexural wave absorber includes an L-shaped cantilever beam lossy acoustic black hole disposed on a surface of a mechanical structure and an L-shaped cantilever beam lossless acoustic black hole disposed on the surface and spaced apart from the L-shaped cantilever beam lossy acoustic black hole a predefined distance. The L-shaped cantilever beam lossy acoustic black hole and the L-shaped cantilever beam lossless acoustic black hole, in combination, are configured to asymmetrically absorb a plurality of different frequencies of flexural waves within at least a 2000 Hz frequency band acting on the mechanical structure. The L-shaped cantilever beam lossy acoustic black hole and the L-shaped cantilever beam lossless acoustic black hole can both include a projecting beam with an outer surface or an inner surface having power law profile.

Abstract: A sound absorbing device includes a chamber with an opening and at least one fabric layer extending across the opening. The at least one fabric layer extending across the opening is at least two fabric layers stacked relative to and in direct contact with each other, at least two fabric layers stacked relative to and spaced apart from each other by a predefined distance, at least one elastic fabric layer configured to vibrate independently from the chamber, or a three dimensional fabric layer. The at least two fabric layers stacked relative to and in direct contact with each other and the at least two fabric layers stacked relative to and spaced apart from each other by a predefined distance are configured to move relative to each other, and the at least one elastic fabric layer is configured to vibrate independently from the chamber.

Abstract: A flexural wave absorber includes a metasurface with an inner portion, an outer portion, and a plurality of beam strips extending between the inner portion and the outer portion. The metasurface also includes a plurality of coupled resonators disposed on the plurality of beam strips. The plurality of coupled resonators can include a lossy resonator and a lossless resonator, two lossy resonators and a lossless resonator, or a lossy resonator and two lossless resonators. In addition, each of the plurality of beam strips can have multiple pairs of coupled resonators disposed thereon that work at or absorb different frequency ranges.

Abstract: A duct includes a duct body defining an inlet, an outlet, and a channel connecting the inlet and the outlet. The duct body also defines an upstream resonator. The upstream resonator includes an upstream annular cavity external to the channel and an annular perforated plate coplanar with the upstream annular cavity. The duct body further defines a downstream resonator. The downstream resonator includes a downstream annular cavity external to the channel and an annular neck coplanar with the downstream annular cavity.

Abstract: Embodiments for one-way sound absorbing systems are described herein. In one example, a sound absorbing system includes a waveguide having open ends for receiving an incoming acoustic wave and wall portions defining a first port and a second port. A first electroacoustic absorber is mounted to the first port and is electrically connected to a shunting circuit, while a second electroacoustic absorber is mounted to the second port and is electrically connected to an open circuit. The sound absorption of the system is directional dependent.

Abstract: A sound absorber can include a housing including a back wall, a perimeter wall, and an interior wall that form cells having cavities. The sound absorber can also include a panel disposed on the housing that substantially faces the back wall and encloses the cavities of the cells. The panel can define groups of holes for each cell such that one group of holes extend though the panel to the cavity of one cell and another group of holes extend through the panel to the cavity of another cell.

Abstract: Described is a system for transmitting a flexural wave acting on one structure to another structure. In one example, a system includes a first structure having a first property and a first end and a second structure having a second property and a second end connected to the first end of the first structure. The first property is different from the second property and may be related to the material and/or geometric properties of the first and second structures. A mechanical resonator is connected to the first structure at a distance from the first end of about a quarter-wavelength of the frequency of a flexural wave acting on the first structure. The mechanical resonator matches a first mechanical impedance of the first structure to a second mechanical impedance of the second structure to allow high transmission of the flexural wave acting on the first structure to the second structure.

Abstract: A wave control system includes a substrate with a plurality of beams spaced apart from each other, a plurality of sensors disposed on the plurality of beams, a plurality of actuators disposed on the plurality of beams, a processor, and a memory communicably coupled to the processor. The memory stores machine-readable instructions that, when executed by the processor, cause the processor to determine a frequency of a fundamental incident wave propagating within and/or incident on the plurality of beams based on a plurality of signals from the plurality of sensors, and control the plurality of actuators to generate at least one of a cancellation wave, a subharmonic wave, and a superharmonic wave, based on the frequency of the fundamental incident wave. In addition, a reflected fundamental wave, the sub harmonic wave, and/or the superharmonic wave can be steered to a desired direction or path along the substrate.

Abstract: Embodiments described herein relate to a bi-functional thermal cooling system. The bi-functional thermal cooling system includes a first body, a second body, and a third body. The second body has a first plurality of Weyl semimetal nanostructures. The second body is spaced apart from the first body. The third body has a second plurality of Weyl semimetal nanostructures. The third body is spaced apart from the second body. The second body and the third body are each configured to independently rotate with respect to the first body to change an optical property of the first plurality of Weyl semimetal nanostructures of the second body and an optical property of the second plurality of Weyl semimetal nanostructures of the third body.

Abstract: Embodiments described herein relate a tunable heat transfer system. The tunable heat transfer system includes a controller, a first body, and a second body. The first body is communicatively coupled to the controller. The second body is communicatively coupled to the controller and spaced apart from the first body. The second body has a plurality of semimetal layers and a dielectric portion positioned between each of the plurality of semimetal layers. Each of the dielectric portions has a thickness to define a gap between each the plurality of semimetal layers in an expanded state and permitting each of the plurality of semimetal layers to abut each other in a contracted state. The controller is configured to change a near-field radiative heat transfer between the first body and the second body by changing the thickness of each of the dielectric portions between the expanded state and the contracted state.

Abstract: A tunable metamaterial structure can have a flexible substrate that is elastically deformable. The tunable metamaterial structure can have a photo-responsive stiffness-modulating patch. The photo-responsive stiffness-modulating patch can be fixed to a surface of the flexible substrate. The photo-responsive stiffness-modulating patch can include a piezoelectric element and a photo-responsive element. The piezoelectric element and the photo-responsive element are electrically connected to one another.

Abstract: A device for superscattering a target acoustic wave may include a body having an outer surface, at least one resonator being defined within the body and extending to an opening defined within the outer surface and configured to cause the superscattering of the target acoustic wave impinging upon the body, and a motor connected to the body and configured to selectively rotate the body.

Abstract: A computer-implemented method for simulating a market index is provided. The method includes: receiving object data from a data source; receiving control data from an input operation applied to the analysis server; identifying one or more first values and one or more second values from the object data, and identifying a first parameter, a second parameter and a third parameter from the control data; inputting the first values, the second values, the first parameter, the second parameter and the third parameter into an executed analysis model; and obtaining an optimized weight vector corresponding to the component stocks from the analysis model, so as to simulate the market index by the weight vector and the prices of the component stocks, wherein the weight vector comprising weight percentages respectively corresponding to the component stocks, and the sum of the weight percentages is equal to one.

Abstract: A method and system of additively-manufacturing a structure having a reinforced access opening includes printing, via an additive printing device having at least one printer head, a portion of the structure adjacent to a support surface. The portion of the structure is printed of a cementitious material, and the printed portion of the structure defines an access opening for the structure. Moreover, the method includes providing a void of the cementitious material at a top boundary of the access opening, placing one or more reinforcement members in the void such that the one or more reinforcement members extend across the void, and continuing to print the printed portion of the structure around the void to build up the structure. Thus, the method also includes backfilling the void with a backfill material to incorporate the one or more reinforcement members within the void into the printed portion of the structure.

Abstract: A method for performing data recovering operation is provided. The method includes: identifying a plurality of first values and a plurality of first indexes of a plurality of first entries of an incomplete matrix in a received object data, and one or more second values and one or more second indexes of one or more second entries of the incomplete matrix; inputting the first values, the first indexes, a preset first parameter, a preset second parameter and a preset third parameter into an analysis model using Adaptive Rank-One Matrix Completion (AROMC) algorithm; and obtaining a recovered complete matrix corresponding to the incomplete matrix from the analysis model, so as to obtain optimized one or more second values of the second entries, wherein the optimized one or more second values are determined as original values of the second entries, such that the incomplete matrix is recovered to the recovered complete matrix.

Abstract: Systems and methods for determining the incident angle of an acoustic wave are presented herein. One embodiment receives an acoustic wave at N transducers, where N is a natural number greater than or equal to 2; solves a set of N coupled differential equations modeling a set of N virtual coupled acoustic resonators using N coupled analog circuits, wherein each of the N coupled analog circuits receives an output signal from a unique one of the N transducers and outputs a voltage signal; and analyzes the N voltage signals output by the N coupled analog circuits to produce an estimate of the incident angle of the acoustic wave.

Abstract: Systems and methods for virtually coupled resonators to determine an incidence angle of an acoustic wave are described herein. In one example, a system includes a processor and first and second transducers in communication with the processor. The first transducer produces a first signal in response to detecting an acoustic wave, while the second transducer produces a second signal in response to detecting the acoustic wave. The system may also include a memory in communication with the processor and having machine-readable instructions that cause the processor to modify the first signal and the second signal using a virtual resonator mapping function to generate a modified first signal and a modified second signal. The virtual resonator mapping function changes the first signal and the second signal to be representative of signals produced by transducers located within a hypothetical chamber of a hypothetical resonator.

Abstract: A system can improve the performance of an electroacoustic absorber. The system includes a loudspeaker and an absorber operatively positioned relative to the loudspeaker. The absorber can be configured to absorb sound waves. A control circuit can be operatively connected to the loudspeaker. The control circuit can be configured to tune the resonance of the loudspeaker and therefore cause one or more acoustic characteristics, such as acoustic impedance, of the loudspeaker to be adjusted.

Abstract: Described are systems for absorbing flexural waves acting on a structure. In one example, the system includes a first resonator connected to a structure at a first location and a second resonator connected to the structure at a second location. The distance between the first location and the second location is based on a frequency of a flexural wave acting upon the structure and an orientation of the first resonator and the second resonator with respect to each other.