Abstract: An in-situ stress measurement device for ultra-deep non-vertical drilling adopts a technical route of single channel and bidirectional rolling of in-hole equipment, and its related functions are mainly realized by a bidirectional rolling device and a split-type axial-force-free circuit switching valve. The bidirectional rolling device can drive the in-hole equipment to move freely in a circumferential direction and back and forth, which changes sliding friction between the in-hole equipment and a hole wall into rolling friction during an in-situ stress measurement of non-vertical drilling. The split-type axial-force-free circuit switching valve provides a technical solution for a single-pipe test in the non-vertical drilling.

Abstract: A padlock comprises a bolt unit having a stopper, a brake unit being moveable up-and-down, and a drive unit for driving the movement of the brake unit. The drive unit includes a drive motor and a driving cap fixedly sleeved on a drive lever. The driving cap includes a lug boss. The brake unit includes a first spring fixedly connected to a tumbler. The spacing of the coils of the first spring matches the lug boss such that the lug boss can move inside or outside of a threaded gap thereof. After the padlock is locked or unlocked, even if the drive lever continues to rotate, the lug boss just moves out of the first spring and may not drive the first spring to move up or down. Thus, the tumbler stops moving up or down and will not generate a pressure on the internal structure of the padlock.

Abstract: Multiple antennas of a beamformer may simultaneously transmit wireless signals at different frequencies. The signals may comprise synchronized, identical wireless commands, each at a different carrier frequency. The transmitted signals may constructively and destructively interfere with each other at a receiver antenna, to form a beat signal. When the transmitted signals constructively interfere, the beat signal may cause a voltage in the receiver to exceed a threshold voltage. The threshold voltage may be a minimum voltage at which a device, which is operatively connected to the receiver antenna, is able to perform energy harvesting or wireless communication. The beamformer may operate under blind channel conditions, because the transmitted frequencies may be selected in such a way as to maximize peak power delivered under all possible channel conditions. The beamformer may deliver wireless power to a sensor or actuator that is located deep inside bodily tissue.

Abstract: A fingerprint padlock comprises a lock case, a lock rope, a locking unit, a lock detecting unit, and a fingerprint unit. The locking unit, a lock detecting unit, and a fingerprint unit are enclosed in the lock case. A lock hole is provided in the lock case. The lock rope comprises a fixed end that is fixed in the lock case and a movable end configured to be inserted into the lock hole. The locking unit is configured to lock and unlock the movable end, and the lock detecting unit is configured to detect whether the movable end is inserted into the lock hole. The fingerprint unit is configured to detect whether the fingerprint of a user is matched and send an unlocking instruction to the locking unit when the fingerprint of the user is matched. The fingerprint padlock is convenient to carry and use.

Abstract: Multiple antennas of a beamformer may simultaneously transmit wireless signals at different frequencies. The signals may comprise synchronized, identical wireless commands, each at a different carrier frequency. The transmitted signals may constructively and destructively interfere with each other at a receiver antenna, to form a beat signal. When the transmitted signals constructively interfere, the beat signal may cause a voltage in the receiver to exceed a threshold voltage. The threshold voltage may be a minimum voltage at which a device, which is operatively connected to the receiver antenna, is able to perform energy harvesting or wireless communication. The beamformer may operate under blind channel conditions, because the transmitted frequencies may be selected in such a way as to maximize peak power delivered under all possible channel conditions. The beamformer may deliver wireless power to a sensor or actuator that is located deep inside bodily tissue.

Abstract: A wideband, radio-frequency localization system may estimate the one-dimensional, two-dimensional or three-dimensional position and trajectory of a static or moving object. These estimates may have a high spatial accuracy and low latency. The localization may be determined based on phase or amplitude of a wideband signal in each frequency band in a set of multiple frequency bands. The localization may be based on a single shot of measurements across a wide band of radio frequencies, without frequency hopping. The measurements of the wideband signal may be taken over time and over space at multiple receivers. The localization may be based on measurements taken while a backscatter node remains in a first reflective state or in a second reflective state, rather than when the backscatter node is transitioning between reflective states. In some cases, the localization achieves sub-centimeter spatial resolution in each of three spatial dimensions.

Abstract: A wideband, radio-frequency localization system may estimate the one-dimensional, two-dimensional or three-dimensional position and trajectory of a static or moving object. These estimates may have a high spatial accuracy and low latency. The localization may be determined based on phase or amplitude of a wideband signal in each frequency band in a set of multiple frequency bands. The localization may be based on a single shot of measurements across a wide band of radio frequencies, without frequency hopping. The measurements of the wideband signal may be taken over time and over space at multiple receivers. The localization may be based on measurements taken while a backscatter node remains in a first reflective state or in a second reflective state, rather than when the backscatter node is transitioning between reflective states. In some cases, the localization achieves sub-centimeter spatial resolution in each of three spatial dimensions.

Abstract: Multiple antennas of a beamformer may simultaneously transmit wireless signals at different frequencies. The signals may comprise synchronized, identical wireless commands, each at a different carrier frequency. The transmitted signals may constructively and destructively interfere with each other at a receiver antenna, to form a beat signal. When the transmitted signals constructively interfere, the beat signal may cause a voltage in the receiver to exceed a threshold voltage. The threshold voltage may be a minimum voltage at which a device, which is operatively connected to the receiver antenna, is able to perform energy harvesting or wireless communication. The beamformer may operate under blind channel conditions, because the transmitted frequencies may be selected in such a way as to maximize peak power delivered under all possible channel conditions. The beamformer may deliver wireless power to a sensor or actuator that is located deep inside bodily tissue.

Abstract: A wideband, radio-frequency localization system may estimate the one-dimensional, two-dimensional or three-dimensional position and trajectory of a static or moving object. These estimates may have a high spatial accuracy and low latency. The localization may be determined based on phase or amplitude of a wideband signal in each frequency band in a set of multiple frequency bands. The localization may be based on a single shot of measurements across a wide band of radio frequencies, without frequency hopping. The measurements of the wideband signal may be taken over time and over space at multiple receivers. The localization may be based on measurements taken while a backscatter node remains in a first reflective state or in a second reflective state, rather than when the backscatter node is transitioning between reflective states. In some cases, the localization achieves sub-centimeter spatial resolution in each of three spatial dimensions.

Abstract: A token management server includes a memory and a data processor. The memory stores a token database and a subledger database. The processor is configured to save a token in the token database in a record in association with a ledger identifier and a subledger identifier. The processor receives from a point-of-sale station a token authorization request that includes the token and an authorization value, locates in the token database the record that includes the token, extracts the ledger identifier and the subledger identifier from the record, locates in the subledger database a subledger that is associated with the subledger identifier, and confirms that a balance value associated with the located subledger is at least equal to the authorization value. The processor then initiates a transfer from a pooling ledger that is associated with the ledger identifier of a transfer amount that is equal to the authorization value.

Abstract: A wideband, radio-frequency localization system may estimate the one-dimensional, two-dimensional or three-dimensional position and trajectory of a static or moving object. These estimates may have a high spatial accuracy and low latency. The localization may be determined based on phase or amplitude of a wideband signal in each frequency band in a set of multiple frequency bands. The localization may be based on a single shot of measurements across a wide band of radio frequencies, without frequency hopping. The measurements of the wideband signal may be taken over time and over space at multiple receivers. The localization may be based on measurements taken while a backscatter node remains in a first reflective state or in a second reflective state, rather than when the backscatter node is transitioning between reflective states. In some cases, the localization achieves sub-centimeter spatial resolution in each of three spatial dimensions.

Abstract: Multiple antennas of a beamformer may simultaneously transmit wireless signals at different frequencies. The signals may comprise synchronized, identical wireless commands, each at a different carrier frequency. The transmitted signals may constructively and destructively interfere with each other at a receiver antenna, to form a beat signal. When the transmitted signals constructively interfere, the beat signal may cause a voltage in the receiver to exceed a threshold voltage. The threshold voltage may be a minimum voltage at which a device, which is operatively connected to the receiver antenna, is able to perform energy harvesting or wireless communication. The beamformer may operate under blind channel conditions, because the transmitted frequencies may be selected in such a way as to maximize peak power delivered under all possible channel conditions. The beamformer may deliver wireless power to a sensor or actuator that is located deep inside bodily tissue.

Abstract: A padlock comprises a bolt unit having a stopper, a brake unit being moveable up-and-down, and a drive unit for driving the movement of the brake unit. The drive unit includes a drive motor and a driving cap fixedly sleeved on a drive lever. The driving cap includes a lug boss. The brake unit includes a first spring fixedly connected to a tumbler. The spacing of the coils of the first spring matches the lug boss such that the lug boss can move inside or outside of a threaded gap thereof. After the padlock is locked or unlocked, even if the drive lever continues to rotate, the lug boss just moves out of the first spring and may not drive the first spring to move up or down. Thus, the tumbler stops moving up or down and will not generate a pressure on the internal structure of the padlock.

Abstract: A fingerprint padlock comprises a lock case, a lock rope, a locking unit, a lock detecting unit, and a fingerprint unit. The locking unit, a lock detecting unit, and a fingerprint unit are enclosed in the lock case. A lock hole is provided in the lock case. The lock rope comprises a fixed end that is fixed in the lock case and a movable end configured to be inserted into the lock hole. The locking unit is configured to lock and unlock the movable end, and the lock detecting unit is configured to detect whether the movable end is inserted into the lock hole. The fingerprint unit is configured to detect whether the fingerprint of a user is matched and send an unlocking instruction to the locking unit when the fingerprint of the user is matched. The fingerprint padlock is convenient to carry and use.

Abstract: A wideband, radio-frequency localization system may estimate the one-dimensional, two-dimensional or three-dimensional position and trajectory of a static or moving object. These estimates may have a high spatial accuracy and low latency. The localization may be determined based on phase or amplitude of a wideband signal in each frequency band in a set of multiple frequency bands. The localization may be based on a single shot of measurements across a wide band of radio frequencies, without frequency hopping. The measurements of the wideband signal may be taken over time and over space at multiple receivers. The localization may be based on measurements taken while a backscatter node remains in a first reflective state or in a second reflective state, rather than when the backscatter node is transitioning between reflective states. In some cases, the localization achieves sub-centimeter spatial resolution in each of three spatial dimensions.