Abstract: This disclosure relates to a digital comparator coupled to a pair of pull-up resistors and a pair of pull-down resistors whereby both pairs of resistors are coupled to an output terminal of a low dropout (LDO) regulator. In particular, the digital comparator comprises an edge detector module, a consecutive two-edge detector module and a consecutive three-edge detector module whereby the edge detector module is configured to receive two clock signals as inputs and after being processed by these three modules, to pull-up or pull-down the resistors at the output terminal of the LDO regulator based on the rising and falling edges of the received clock signals.

Abstract: The present disclosure discloses a visual monitoring system of crack propagation of an underwater structure based on an alternating current field, and an alternating current field crack visual monitoring and evaluation method.

Abstract: An apparatus and a method for measuring a microwave electric field at continuous frequencies based on an alternating current (AC) Stark effect of Rydberg atoms. A cesium vapor cell is used as an atomic sample cell. A cesium atom is excited to a Rydberg state by using detection light and coupling light that are emitted by two laser light sources, an electromagnetically induced transparency spectrum is generated. Further, a strong electric field is used as a local field EL, to cause AC Stark frequency shift and splitting of a Rydberg energy level. ES of to-be-detected signal electric field is applied. In this case, the Rydberg atom serves as a frequency converter, to directly read a beat frequency signal ?f of the local field and the signal field. From the beat signal, the strength of Es of signal filed can be directly read out.

Abstract: An apparatus and a method for measuring a microwave electric field at continuous frequencies based on an alternating current (AC) Stark effect of Rydberg atoms. A cesium vapor cell is used as an atomic sample cell. A cesium atom is excited to a Rydberg state by using detection light and coupling light that are emitted by two laser light sources, an electromagnetically induced transparency spectrum is generated. Further, a strong electric field is used as a local field EL, to cause AC Stark frequency shift and splitting of a Rydberg energy level. ES of to-be-detected signal electric field is applied. In this case, the Rydberg atom serves as a frequency converter, to directly read a beat frequency signal ?f of the local field and the signal field. From the beat signal, the strength of ES of signal filed can be directly read out.

Abstract: The vertical counterforce loading device includes a concrete support member, four transfer components, four connection components, a vertical force transmission component and a load test soil layer. The concrete support member is formed by pouring and concreting below the load test soil layer. The four transfer components are divided into two groups to be symmetrically and parallelly anchored in the concrete support member. The vertical force transmission component includes a load plate, a jack, a primary beam and a secondary beam arranged in sequence from bottom to top. The load plate is installed on the load test soil layer. Two secondary beams are connected crosswise to both ends of the primary beam, where end portions of the secondary beams are respectively connected to second ends of the connection components through reinforcement components. The device can improve work efficiency, reduce construction costs and improve safety.

Abstract: This disclosure relates to a digital comparator coupled to a pair of pull-up resistors and a pair of pull-down resistors whereby both pairs of resistors are coupled to an output terminal of a low dropout (LDO) regulator. In particular, the digital comparator comprises an edge detector module, a consecutive two-edge detector module and a consecutive three-edge detector module whereby the edge detector module is configured to receive two clock signals as inputs and after being processed by these three modules, to pull-up or pull-down the resistors at the output terminal of the LDO regulator based on the rising and falling edges of the received clock signals.

Abstract: The vertical counterforce loading device includes a concrete support member, four transfer components, four connection components, a vertical force transmission component and a load test soil layer. The concrete support member is formed by pouring and concreting below the load test soil layer. The four transfer components are divided into two groups to be symmetrically and parallelly anchored in the concrete support member. The vertical force transmission component includes a load plate, a jack, a primary beam and a secondary beam arranged in sequence from bottom to top. The load plate is installed on the load test soil layer. The number of the secondary beams is two, and the two secondary beams are connected crosswise to both ends of the primary beam. The end portions of the two secondary beams are respectively connected to second ends of the four connection components through reinforcement components.

Abstract: The present invention relates to a trusted measurement and control network authentication method based on double cryptographic values and chaotic encryption. The specific method comprises realizing identity authentication and key negotiation processes through double cryptographic values and chaotic public key ciphers and realizing secure transmission and verification of user identity credentials on the basis of building a trust chain through trusted computation for realizing a secure and trusted operating environment, thereby building a secure and trusted data transmission channel. The identity authentication method in the present invention comprises multiple links such as secure generation of user identity identifiers, read protection encapsulation, secure transmission and key negotiation. Each link adopts a unique and confidential cryptographic function for secure data generation, thereby ensuring the security of the authentication device access in an industrial measurement and control network.

Abstract: The present invention relates to a security processing unit of PLC and a bus arbitration method thereof, to provide PLC with an active defense means to build a PLC hardware and software security layer. On a hardware security layer, a part of hardware processing mechanism is added to support trusted measurement, encryption algorithms and signature algorithms, and a virtual isolation technology is used; and on a software security layer, transparent encryption and decryption, integrity verification, backup recovery and virtual isolation security mechanism are provided. The security processing aspect is improved to achieve the purpose of security and reliability. The present invention can correctly establish a trusted environment of PLC to ensure that PLC is guided by a strictly verified path. A new star type trusted structure is designed to reduce loss during information transmission and increase information transmission efficiency.

Abstract: The present invention relates to a network guard unit for an industrial embedded system and a guard method. The specific method is to form the network guard unit (NGU) through security technologies, such as integrated access control, identity authentication and communication data encryption, to provide active guard for a site control device. The NGU comprises an access control module, an identity authentication module, a data encryption module, a key negotiation module and a PCIE communication module, and supports the communication modes of dual network cards and PCIE bus. The present invention builds a secure and trusted operating environment for industrial control systems in combination with an active guard technical means in the field of information security on the basis of ensuring the correctness and the feasibility of security of various terminal devices in the industrial control systems.

Abstract: The present invention relates to a dynamic security method and system based on multi-fusion linkage response. In the method, a site control device conducts active response and passive response through identity authentication and key management to give an alarm for abnormal behaviors. The system comprises an access authentication active response module, an access control active response module, an access control passive response module, an abnormal pretending passive response module, a key vulnerability passive response module and an abnormal state passive response mechanism module. On the basis of ensuring validity and feasibility for the security of a terminal device, the present invention can build a secure and trusted industrial control system operating environment.

Abstract: The present invention discloses a method for trusted booting of PLC based on a measurement mechanism, comprising the following steps: a step of initializing self firmware verification; a step of reading and computing firmware information about a PLC; a step of checking and storing one by one; and a step of verifying at the operation start stage. In the method of the present invention, a chip with a trusted function is used as a core of hardware computation. The PLC extends a Flash bus for loading by hardware of the method of the present invention. The hardware of the method of the present invention recognizes necessary boot information, verifies the integrity of the boot loader necessary for the PLC system through the integrity check method and ensures that the booted PLC system is in a trusted state. On the basis of ensuring validity and feasibility for the safety of a terminal device, the present invention can build a safe and trusted industrial control system operating environment.

Abstract: The present invention relates to a working condition state modeling and model correcting method, comprising collecting data, and arranging the data in a chronological order to form a time sequence data set; preprocessing the time sequence data set; clustering the preprocessed time sequence data set, computing a central point data set of the duster, and generating a working condition data set and a working condition process data set; counting a working condition transition probability for the working condition process data set to form a working condition transition probability model data set; collecting the data, and detecting and processing the data; computing a working condition state transition mode phase by phase and processing.

Abstract: The present invention relates to a network guard unit for an industrial embedded system and a guard method. The specific method is to form the network guard unit (NGU) through security technologies, such as integrated access control, identity authentication and communication data encryption, to provide active guard for a site control device. The NGU comprises an access control module, an identity authentication module, a data encryption module, a key negotiation module and a PCIE communication module, and supports the communication modes of dual network cards and PCIE bus. The present invention builds a secure and trusted operating environment for industrial control systems in combination with an active guard technical means in the field of information security on the basis of ensuring the correctness and the feasibility of security of various terminal devices in the industrial control systems.

Abstract: A method for starting a trusted embedded platform based on TPM industrial control includes taking a Core Root of Trust Measurement (CRTM) as a source of a trust chain and executing CRTM after electrifying an embedded platform; conducting trust measurement of BIOS and starting BIOS after passing measurement; BIOS measuring Bootloader and extending a measured value into PCR corresponding to TPM; after passing the measurement, transferring a control execution right to Bootloader; and Bootloader measuring OS kernel start process, recording a measured value into PCR of TPM, and executing a start flow of OS after passing the measurement. The method performs measurement before start of each part of a start process, and measured values are also stored in the PCR corresponding to TPM. When the start process is tampered by an attacker, an integrity measurement mechanism terminates the execution of a program, thereby ensuring the security of the embedded platform.

Abstract: The present invention relates to a security processing unit of PLC and a bus arbitration method thereof, to provide PLC with an active defense means to build a PLC hardware and software security layer. On a hardware security layer, a part of hardware processing mechanism is added to support trusted measurement, encryption algorithms and signature algorithms, and a virtual isolation technology is used; and on a software security layer, transparent encryption and decryption, integrity verification, backup recovery and virtual isolation security mechanism are provided. The security processing aspect is improved to achieve the purpose of security and reliability. The present invention can correctly establish a trusted environment of PLC to ensure that PLC is guided by a strictly verified path. A new star type trusted structure is designed to reduce loss during information transmission and increase information transmission efficiency.

Abstract: The present invention discloses a method for controlling transmission security of an industrial communication flow based on an SDN architecture. The method comprises: designing a flow security control module in a management controller, performing in-depth parsing on industrial communication flow data, matching the parsing result with each preset industrial rule policy, and executing a control processing operation of the industrial rule policy, to implement transmission control of an industrial communication flow. The management controller comprises an industrial rule policy database used for storing all industrial rule policies set by a user. An SDN switch maintains a structure of a flow table, and an industrial communication flow is forwarded according to the flow table. The flow table comprises a security control identifier used for indicating whether security transmission of this communication flow needs to be controlled.

Abstract: A method and a device for processing a speech instruction are provided. With the method, a speech instruction is recognized so as to generate text information corresponding to the speech instruction. Semantic analysis is performed on the text information so as to obtain a semantic analysis result of the text information. Whether a corresponding operation is executable based on the semantic analysis result of the text information is determined. If it is determined that the corresponding operation is not executable based on the semantic analysis result of the text information, whether the text information belongs to instruction text data is determined. If yes, the text information is corrected so as to obtain corrected text information. Semantic analysis is performed on the corrected text information, and the corresponding operation is executed according to a semantic analysis result of the corrected text information.

Abstract: The present invention relates to a dynamic security method and system based on multi-fusion linkage response. In the method, a site control device conducts active response and passive response through identity authentication and key management to give an alarm for abnormal behaviors. The system comprises an access authentication active response module, an access control active response module, an access control passive response module, an abnormal pretending passive response module, a key vulnerability passive response module and an abnormal state passive response mechanism module. On the basis of ensuring validity and feasibility for the security of a terminal device, the present invention can build a secure and trusted industrial control system operating environment.

Abstract: Proposed is an anomaly detection method for communication behaviors in an industrial control system based on an OCSVM algorithm. According to the present invention, a normal behavior profile model and an abnormal behavior profile model, i.e. a dual-outline model, of communication behaviors in an industrial control system are established, parameter optimization is performed by means of a particle swarm optimization (PSO) algorithm, an optimal intrusion detection model is obtained, and abnormal Modbus TCP communication traffic is identified. According to the present invention, the false alarm rate is reduced by means of cooperative discrimination of the dual-outline detection model, the efficiency and reliability of anomaly detection are improved, and the method is more applicable to practical applications.