Abstract: A linear acceleration sensor and an operating method for the same are provided. The sensor elements installed in the linear acceleration sensor include an accelerometer and a gyroscope. The accelerometer is used to measure acceleration values along axes of the linear acceleration sensor over a period of time. The gyroscope is used to measure angular velocities of the sensor over the period of time. In the operating method, the measurement data from the accelerometer and the gyroscope are transformed to a reference frame through a mapping process. A filtering process is performed on the mapped data in order to separate a gravity value from the data. Therefore, the motion signals with respect to the linear acceleration sensor can be obtained.

Abstract: The disclosure is related to a method for avoiding misjudgment when detecting a human fall, and an apparatus thereof. When the apparatus worn on a person generates a collision signal, it determines if the apparatus was in a proper status in the past period of time before the collision according to the acceleration data. The apparatus was in the proper status if a specific axial direction of an accelerometer of the apparatus is substantially parallel with the direction of gravity, and the method goes on detecting the human fall; otherwise, the process is terminated. The acceleration data before and after the collision is compared with fall conditions set by a fall detection program. A fall event is determined if the acceleration data meets the fall conditions.

Abstract: A chained wireless communication system is provided. The system includes a main node and a plurality of communication nodes. The communication nodes are chained to form a chain network. The communication node can switch roles among a master connection unit, a slave connection unit and a signal scanning unit. The signal scanning unit can scan nearby terminal devices and generate scan packets. The scan packets are transmitted to neighboring communication nodes via the slave connection unit. The master connection unit of the neighboring communication node receives the scan packets. The scan packets are then delivered to the main node via this chain network. The main node retrieves a message delivered from the terminal device according to an identification message from the scan packets. The message delivered from the terminal device is used to locate the terminal device, notify an emergency event or serve as a sensing signal.

Abstract: A wearable device with movement indicator, a system and a method for movement indication are provided. The movement indication is implemented on the wearable device. The wearable device receives a movement instruction from a computing host. The movement instruction includes a direction signal that may be accompanied with further instructions such as strength and direction. The instructions are displayed through the movement indicator of the wearable device. A user who wears the wearable device moves in response to a moving instruction. A motion sensor of the wearable device senses a movement signal and obtains a moving direction. Other signals of strength and distance may also be obtained by the motion sensor. After that, the system can score the movement of the wearable device based on the original movement instruction.

Abstract: A wearable device with movement indicator, a system and a method for movement indication are provided. The movement indication is implemented on the wearable device. The wearable device receives a movement instruction from a computing host. The movement instruction includes a direction signal that may be accompanied with further instructions such as strength and direction. The instructions are displayed through the movement indicator of the wearable device. A user who wears the wearable device moves in response to a moving instruction. A motion sensor of the wearable device senses a movement signal and obtains a moving direction. Other signals of strength and distance may also be obtained by the motion sensor. After that, the system can score the movement of the wearable device based on the original movement instruction.

Abstract: The disclosure is related to a method and an apparatus for human fall detection with power-saving feature. In the method, a processor is set in a sleep state under a normal operating condition, and sensor data generated by a sensor unit of the apparatus worn on a person is stored in a buffer. A processor of the apparatus is woken up from a sleep state when the processor receives a collision signal, and the processor then retrieves the buffered sensor data and current sensor data. The sensor data is processed by a fall detection program. The apparatus will generate an alarm for a fall event if the sensor data meets the preset fall conditions; otherwise, the processor returns to the sleep state. The apparatus saves power by avoiding huge data calculation while staying in the sleep state until being woken up by the collision signal.

Abstract: The disclosure is related to a method for avoiding misjudgment when detecting a human fall, and an apparatus thereof. When the apparatus worn on a person generates a collision signal, it determines if the apparatus was in a proper status in the past period of time before the collision according to the acceleration data. The apparatus was in the proper status if a specific axial direction of an accelerometer of the apparatus is substantially parallel with the direction of gravity, and the method goes on detecting the human fall; otherwise, the process is terminated. The acceleration data before and after the collision is compared with fall conditions set by a fall detection program. A fall event is determined if the acceleration data meets the fall conditions.

Abstract: A jitter measurement circuit and a method for calibrating the jitter measurement circuit are disclosed. The jitter measurement circuit includes a synchronous dual-phase detector and a decision circuit. In a test mode, a probability distribution function (PDF) of the jitter of a clock signal output by a circuit under test is obtained. In a calibration mode, a random clock, which is externally generated or generated by a free-run oscillator in the circuit under test, is used to calibrate the synchronous dual-phase detector. The decision circuit performs logic operations, data latching and counting on a phase relationship detected by the synchronous dual-phase detector in order to obtain a counting value and a PDF relative to the jitter of the clock signal.

Abstract: A jitter measurement circuit and a method for calibrating the jitter measurement circuit are disclosed. The jitter measurement circuit includes a synchronous dual-phase detector and a decision circuit. In a test mode, a probability distribution function (PDF) of the jitter of a clock signal output by a circuit under test is obtained. In a calibration mode, a random clock, which is externally generated or generated by a free-run oscillator in the circuit under test, is used to calibrate the synchronous dual-phase detector. The decision circuit performs logic operations, data latching and counting on a phase relationship detected by the synchronous dual-phase detector in order to obtain a counting value and a PDF relative to the jitter of the clock signal.

Abstract: Disclosed is a sample and hold circuit for detecting a parameter of a data signal, which includes: a first switching module, wherein the sample and hold circuit samples the data signal according to the turning on or off of the first switching module; at least one capacitor, coupled to the first switching module; a second switching module, coupled to the capacitor; a controllable reference voltage source, for providing a first reference voltage to charge/discharge the capacitor via the second switching module according to a control signal; a first comparator, coupled to the capacitor, for comparing a voltage drop on the capacitor and the first reference voltage to generate a first comparing result; and a control circuit, coupled to the controllable reference voltage source and the first comparator, for generating the control signal according to the comparing results.

Abstract: Disclosed is a sample and hold circuit for detecting a parameter of a data signal, which includes: a first switching module, wherein the sample and hold circuit samples the data signal according to the turning on or off of the first switching module; at least one capacitor, coupled to the first switching module; a second switching module, coupled to the capacitor; a controllable reference voltage source, for providing a first reference voltage to charge/discharge the capacitor via the second switching module according to a control signal; a first comparator, coupled to the capacitor, for comparing a voltage drop on the capacitor and the first reference voltage to generate a first comparing result; and a control circuit, coupled to the controllable reference voltage source and the first comparator, for generating the control signal according to the comparing results.