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In previous studies, acoustical levitation in the far-field was limited to particles. Here, this paper proposes the “boundary hologram method,” a numerical design technique to generate a static and stable levitation field for macroscopic non-spherical rigid bodies larger than the sound wavelength λ. This paper employs boundary element formulation to approximate the acoustic radiation force and torque applied to a rigid body by discretizing the body surface, which is an explicit function of the transducer's phase and amplitude. Then, the drive of the phased array is numerically optimized to yield an appropriate field that stabilizes the body's position and rotation. In experiments, this paper demonstrates the levitation in air of an expanded polystyrene sphere with a diameter of 3.5 λ and a regular octahedron with diagonal length of 5.9 λ, both located 24 λ from the acoustic elements, by a 40 kHz (λ = 8.5 mm) ultrasonic phased array. This method expands the variety of objects that can be levitated in the far-field of an ultrasonic phased array.

In this paper, we report the latest results of our two-dimensional communication project. In the system we show here, the sensor node that touches the surface of a Two-Dimensional Signal Transmission sheet (2DST sheet) establishes the connection. The system allows free location of the sensor node, and proximity (non-contact) connection is realized stably. The structure of 2DST sheet is simple and realized with various materials at low cost. Since the sensor nodes communicate with electromagnetic waves confined in two-dimensional medium, they are free from the interference from the nodes apart from the sheet. Powering with microwave through the sheet is also possible. Keywords-sensor network; surface LAN; two-dimensional communication I. INTRODUCTIONPhysical connection of a large number of sensors is one of key issues in sensor networking in rooms, vehicles, and clothes. Radio connection is often the method that minimizes the cost of the sensor placement, and in some cases, the only way to distribute sensors over a large area of farmland and mountainous field. In those applications, the main research theme of sensor network is communication protocols to extremely save the energy consumptions under limited batteries.In communication within a room-size or smaller area, we can suppose preferable physical forms of connection other than wireless communication. Surface LAN realized by two-dimensional signal transmission (2DST [6][7][8][9]]) is a reasonable communication form that realizes high density placement of sensors enjoying wide band communication. In this paper, we report the latest results of our 2DST project. In the proposed system, the sensor node that touches the surface of a 2DST sheet establishes the connection. The system allows free location of the sensor node where proximity (non-contact) connection is realized stably.In communication of 2DST, the sensor nodes communicate using microwave which propagates in two-dimensional sheet. The first merit of 2DST is that the communication is free from the interference [1] from unexpected signals outside of the room. The sensors belonging to a 2DST sheet is also harmless to the sensors apart from the sheet. The second important merit

A Mid to Late Holocene sea‐level record based on combined geomorphological, geological and micropaleontological observations was obtained from well‐developed wave cut benches subaerially exposed along the Shimokita Peninsula, northern Japan. Results indicate that the benches were formed during mid to late Holocene sea‐level transgressions, reaching a maximum highstand level of 2 m above present at about 4,000 years ago. This timing corresponds to an abrupt, order of magnitude decrease in sedimentation rate as recorded in a core recovered from proximal Mutsu Bay. In addition, glacio‐hydro‐isostatic adjustment due to crustal deformation in response to postglacial sea‐level rise was modeled, and results are consistent with the reconstructed local 2 m highstand. Given that meltwater contributions from the major North American and European ice sheets had largely ceased by 7,000 years ago, these independent lines of evidence, taken together, indicate that melting of the Antarctic ice sheet ended by 4,000 years ago.

Figure 1: (a) A user can grasp and move a 3D object image. (b) The cross section of the finger is estimated. (c) The ultrasound focus moves around the cross section and generates a pressure distribution on the finger surface.

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