Abstract: A method (50) of, a node device (100) and a computer program product arranged for alerting node devices in a network of operatively interconnected node devices by transmitting an alerting message comprising a geographic location address of an originator node device (21) transmitting the alerting message and a moving direction (12) of an object (11) receiving service from the originator node device (21). When a receiving node device (24, 25) determines, based on its geographic location address, the geographic location address of the originator node device (21) and the moving direction (12), that the object (11) is approaching the receiving node device (24, 25), it transmits the alerting message comprising the geographic location address of the originator node device (21) and the moving direction (12).

Abstract: A barcode reading method and a barcode reading device are provided. An image sensor is utilized to capture an image of a barcode via an optical lens, and then a triangulation method and an ideal lens imagining method are collocated to calculate the digital image so as to produce an optimum image distance. A distance between the image sensor and the optical lens is then adjusted in accordance with the optimum image distance, so that the barcode can be immediately and clearly imaged on the image sensor.

Abstract: A barcode reading method and a barcode reading device are provided. An image sensor is utilized to capture an image of a barcode via an optical lens, and then a triangulation method and an ideal lens imagining method are collocated to calculate the digital image so as to produce an optimum image distance. A distance between the image sensor and the optical lens is then adjusted in accordance with the optimum image distance, so that the barcode can be immediately and clearly imaged on the image sensor.

Abstract: A ballast device having active ballasting circuit and method thereof, which are used for controlling a HID lamp's power supply real-timely and steadily, comprising: a power supply unit in said ballast device for generating an outer working voltage, which has a DC-DC transformer to step down the output voltage; a micro control unit, which fetches the parameters of the ballast device other than itself or the HID lamp's various working status and generates a predefined load current by these parameters; a PWM control unit, which has a PID control module, the PID control module calculates said predefined load current and the HID lamp's practical load current, and makes said DC-DC transformer change it's output voltage by the calculate results. The present invention has a simple structure and can change the load current real-timely and steadily.

Abstract: A ballast device having active ballasting circuit and method thereof, which are used for controlling a HID lamp's power supply real-timely and steadily, comprising: a power supply unit in said ballast device for generating an outer working voltage, which has a DC-DC transformer to step down the output voltage; a micro control unit, which fetches the parameters of the ballast device other than itself or the HID lamp's various working status and generates a predefined load current by these parameters; a PWM control unit, which has a PID control module, the PID control module calculates said predefined load current and the HID lamp's practical load current, and makes said DC-DC transformer change it's output voltage by the calculate results. The present invention has a simple structure and can change the load current real-timely and steadily.