Abstract: This specification provides a method and an apparatus for estimating a word segment frequency in differential privacy protection data, and an electronic device. According to the method, each piece of word segment information that is reported by a terminal device and that is subject to local differential privacy processing is obtained; N groups of word segment information are obtained through division, so each piece of word segment information of the same group corresponds to the same target quantity; each group of estimated data that is corresponding to each group of word segment information and that represents unbiased word segment frequency estimation is determined; and each layer of nodes of a prefix tree used to record a word segment frequency is generated layer by layer based on each group of estimated data.

Abstract: The present disclosure provides a method and system for monitoring an application. The method includes creating a simulated system service; establishing a connection with a function in a device driver that manages an Input/Output (I/O) channel of the device; intercepting data transmitted from the application to the function in the device driver that manages the I/O channel of the device; replacing, based on the intercepted data, a system service requested by the application with a corresponding simulated system service; and recording a request received by the simulated system service and forwarding the request to an analysis module for analysis.

Abstract: A method and system for cleaning up junk files on a mobile terminal are provided. The method comprises: scanning, by a mobile terminal client, a file system on a local mobile terminal to generate a list of file information; submitting, by the mobile terminal client, to a server side the list of file information; comparing, by the server side, the list of file information submitted by the client with an associated list of file information in a server side database and returning the comparison result; determining a request for cleaning up in the file system on the basis of the comparison result, and performing, by the mobile terminal client, an operation of cleaning up.

Abstract: The present disclosure provides a method and system for monitoring an application. The method comprises creating a simulated system service; establishing a connection with a function in a device driver that manages an Input/Output (I/O) channel of the device; intercepting data transmitted from the application to the function in the device driver that manages the I/O channel of the device; replacing, based on the intercepted data, a system service requested by the application with a corresponding simulated system service; and recording a request received by the simulated system service and forwarding the request to an analysis module for analysis. The present disclosure is advantageous in that the system request is intercepted during the Binder communication process of the system and the simulated system layer service is used for analyzing the behavior features of the application in the Android operating system.

Abstract: A method and system for scanning redundant files of a mobile terminal by using cloud computing are provided. The method comprises: scanning, by a client on the mobile terminal, a file system on a local mobile terminal to generate a list of file information; submitting, by the client on the mobile terminal, to a server side the list of file information; comparing, by the server side, the list of file information received by the server side with an associated list of file information in a server side database and returning the comparison result; comparing, by the client, the comparison result returned by the server side with the application list of the mobile terminal; performing, by the client, a cleanup operation based on the comparison result of the client.

Abstract: The present disclosure provides an information recommendation method and system based on message content. The method comprises the following steps: when a message is viewed at a user side, providing a guiding option to a user; if the user triggers the guiding option, then performing single-level classification or multi-level classification on the message to obtain category information; and a server returning information related to the category information to the user side.