Abstract: A computing device provides a resonance algorithm to process digital signal data according to a principle of physical resonance. The resonance algorithm determines a division length n of digital signal data according to a frequency f1 of an audio signal to be detected and a sampling frequency f2, which is used for sampling the digital signal data by a coder. Furthermore, the resonance algorithm divides the digital signal data into a serial of data segments by the division length n, and obtains enhanced digital signal data by accumulating a number m of the data segments.

Abstract: In a method for detecting an event occurred in a monitoring area, the method defines a reference characteristic parameter for a specific event, and stores the reference characteristic parameter in a storage device of the computing device. The method further obtains a voice stream of the specific event from an IP camera through a wireless network in real time, and extracts a characteristic parameter from the voice stream using a predefined algorithm. The method compares the extracted characteristic parameter with the reference characteristic parameter, and determines that the specific event occurs in the monitoring area if the extracted characteristic parameter accords with the reference characteristic parameter.

Abstract: A computing device provides a resonance algorithm to process digital signal data according to a principle of physical resonance. The resonance algorithm determines a division length n of digital signal data according to a frequency f1 of an audio signal to be detected and a sampling frequency f2, which is used for sampling the digital signal data by a coder. Furthermore, the resonance algorithm divides the digital signal data into a serial of data segments by the division length n, and obtains enhanced digital signal data by accumulating a number m of the data segments.

Abstract: A data security protection method generates dynamic encryption keys and dynamic decryption keys for a host and a client during data transmission between the host and the client. The host stores a host initial key K0, and determines a host key Kn using a one-way hash function based on the host initial key K0. The client stores a client initial key K?0, and determines a client key K?n using the one-way hash function based on the client initial key K?0. Original data Rn is encrypted as encrypted data Xn using the host key Kn before being sent to the client. The client decrypts the encrypted data Xn using the client key K?n, to obtain the original data Rn.

Abstract: A water supply control method for a water tower connected to a server through a high water level sensor and a low water level sensor installed on the water tower. A solar panel is controlled to supply power to a motor of the water tower during off-peak hours and a current water level in the water tower has reached a lowest water level but has not reached a highest water level. An alternating current power supply is controlled to supply power to the motor during off-peak hours and the current water level in the water tower has not reached the lowest water level, or during peak hours and the current water level in the water tower has not reached the highest water level.

Abstract: A data security protection method generates dynamic encryption keys and dynamic decryption keys for a host and a client during data transmission between the host and the client. The host stores a host initial key K0, and determines a host key Kn using a one-way hash function based on the host initial key K0. The client stores a client initial key K?0, and determines a client key K?n using the one-way hash function based on the client initial key K?0. Original data Rn is encrypted as encrypted data Xn using the host key Kn before being sent to the client. The client decrypts the encrypted data Xn using the client key K?n, to obtain the original data Rn.

Abstract: An electronic device connects with one or more Internet Protocol (IP) cameras via a network. The electronic device receives a first real-time image of a monitored area captured by an IP camera at a first resolution, compares the first real-time image with an initial image of the monitored area, to determine if suspicious activity appears in the monitored area. If suspicious activity appears in the monitored area, the electronic device generates and sends a control command to the IP camera via the network, to automatically adjust the resolution of the IP camera from the first resolution to a second resolution.