Beijing University of Technology

Beijing Qihoo Technology Company Limited

Zhifeng Liu

Bo Zhang

Tong Yao

Mengmeng Liu

Qinglong Kong

Caixia Zhang

Aijun Jiang

Jing Li

Tao N Zhang

Yongsheng Zhao

Junmin Chen

Caixia Xu

Congbin Yang

Hongyan Chu

Shuxin Bi

The invention disclosed a friction coefficient measuring device under the condition of material periodic deformation. The measuring device is mainly composed of a torque sensor, a sleeve system, an upper sample, a lower sample, a flexible fixture, an air bearing, a clamping system, a tension-compression sensor, a support rod, and a support table. A working module of a friction-wear testing machine is connected with the torque sensor and then connected with the sleeve system to fix the upper sample. A rotating module of the friction-wear testing machine is used for connecting the flexible fixture to fix the lower sample. The tension-compression sensor can accurately measure the radial force between the upper sample and the lower sample. The torque sensor can measure the load torque values of the upper sample and lower sample during testing. According to the curve of the load torque value and radial load value change between the upper sample and lower sample, the friction coefficient between the flexible bearing and flexible gear is obtained.

Device for measuring friction coefficient under the condition of material periodic deformation

The present disclosure discloses a detecting device and method for acoustic emission on high-frequency motion rubbing pair surface. A linear reciprocating slide system with high efficiency and high conductivity is designed based on the method. Reciprocating linear slide system is the main structure of the detection device which is is composed of probe plate, tight clips, vacuum cover, slip wire and insulation box. The reciprocating slide solves the problem of data distortion caused by high frequency jitter when connecting ordinary data lines, and can realize stable and reliable connection between high frequency reciprocating rubbing experiment and acoustic emission detection equipment. The acoustic emission probe on the surface of rubbing pair connects with the preamplifier by linear reciprocating slide. Real-time monitoring of acoustic emission equipment is realized to obtain the state change of rubbing pair surface during high-frequency reciprocating rubbing, and further analyze the wear mechanism of different rubbing pair.

Detecting device and method for acoustic emission on high-frequency motion rubbing pair surface

Embodiments relate to devices and/or methods for measuring three-dimensional contact stiffness of spur gear based on rough surfaces. A hexagonal mesh is used for partitioning, and areas of each square meshes are identical with respect to tooth surfaces. The embodiments include calculating contact pressure distribution of smooth tooth surface based on a finite element method and extracting node pressure of contact area P; and calculating contact stiffness of gear surface. Measurement herein is more precise and avoid disadvantages generated by hertz theory and the free-sliding interface. Gear stiffness properties and calculation methods are influenced by roughness parameters during rough tooth surface contacting processes. The embodiments use a finite element 3D contact stiffness calculation model, which is more accurate than former 2D calculation model or calculation formula. Errors associated with fabrication and manufacture processes are considered to makes gear contact stiffness more accurate and to establish the foundation of gear dynamics.

Device and method for measuring three-dimensional contact stiffness of spur gear based on rough surface

The invention discloses a cloud security-based file processing method and apparatus. The method comprises: generating a signature identifier uniquely corresponding to an unknown program file downloaded locally according to signature related information of the unknown program file; sending a query request to a server end to query whether the unknown program file is a malicious program or not, wherein the query request carries the signature identifier of the unknown program file and a part or all of the file features of the unknown program file; and receiving a feedback message from the server end, and performing subsequent process on the unknown program file according to the feedback message, wherein the server end generates the feedback message according to the signature identifier and the file features. The invention solves the problem of breaking through the cloud killing by utilizing a Trojan in the prior art and at the same time can also reduce the time from discovering a malicious program to killing the malicious program, thereby accelerating the speed of fighting against a new malicious program, reducing the information storage amount of the server as well and in turn guaranteeing the security of a client program.

Cloud security-based file processing by generating feedback message based on signature information and file features

The invention discloses a scanning device, a cloud management device, a method and system for checking and killing a malicious program. Therein, a cloud management device for checking and killing a malicious program comprises: a second transmission interface; a first indicator configured to generate a first scanning content indication according to characteristics of a newborn malicious program and system environment information transmitted by a client device; a first matcher configured to obtain via the second transmission interface feature data of the unknown program file transmitted by the client device, and hereby perform matching in known records of feature data of malicious programs; and a second indicator configured to generate a second scanning content indication when the first matcher fails to match to a known record, the second scanning content indication comprising scanning a specified attribute of the unknown program file and/or a specified attribute of the contextual environment of the unknown program file, and transmit the same to the client device through the second transmission interface.

Scanning device, cloud management device, method and system for checking and killing malicious programs

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Beijing, China

Zhifeng Liu