Abstract: Disclosed is a software PUF based on an RISC-V processor for IoT security. A 32-bit RISC-V processor is used to generate abnormal information results in an abnormal operating state under a low voltage, and the abnormal information results are used to represent the features of the 32-bit RISC-V processor; 5-bit binary data obtained by comparing the abnormal information results with normal information results has high randomness and uniqueness and it is extremely difficult to directly extract internal abnormal information result from a hardware circuit of the 32-bit RISC-V processor, so modeling attacks based on the 5-bit binary data calculated according to the abnormal information results of the 32-bit RISC-V processor are almost impossible; in addition, when the 32-bit RISC-V processor is in an abnormal operating state, the operating frequency of the 32-bit RISC-V processor is dynamically adjusted through a frequency compensation method.

Abstract: A strong and weak hybrid PUF circuit comprises N switch units and an arbiter. Each switch unit consists of two delay modules and two 2:1 multiplexers. The N switch units constitute two completely symmetrical delay paths. Each delay module consists of six stages of delay cells. During the operating process, a transmission signal selects a turn-on path of the corresponding 2:1 multiplexers according to activation signals; the switch units in the PUF circuit are in a valid state (if the delay modules are turned on) or in an invalid state (if the delay modules are not turned on) according to whether the delay modules are turned during the operating process; and the strong and weak hybrid PUF circuit can be flexibly configured to be of two different types (a strong PUF circuit and a weak PUF circuit) according to changes of the Hamming weight of input activation signals.

Abstract: The present disclosure discloses a monitoring device for internal deformation and fine particle loss of a railway subgrade, relating to the field of monitoring devices. The monitoring device includes an internal damage monitoring device arranged in a subgrade ballast layer. The internal damage monitoring device is connected to a resistance acquisition instrument through a wire. The resistance acquisition instrument is in wireless connection with a resistance signal receiver. The monitoring device for internal deformation and fine particle loss of a railway subgrade provided by the present disclosure can remotely realize real-time continuous monitoring of the deformation and fine particle loss inside the railway subgrade under a rail transit load, is economical and convenient, and has high practice value.

Abstract: An adaptive anti-aging sensor based on a cuckoo algorithm, comprising a control module, a reference voltage-controlled oscillator, two shaping circuits, a frequency difference circuit, a resolution adjustment circuit, a 16-bit counter, a parallel-to-serial circuit, an adaptive module, and a digital-to-analog converter. A lookup table is prestored in the adaptive module; when aging monitoring is performed on a voltage-controlled oscillator in an integrated circuit, the adaptive module uses the cuckoo algorithm to determines the optimal working voltage of the currently monitored voltage-controlled oscillator, and the control module accordingly changes the input voltage of the voltage-controlled oscillator of the integrated circuit.

Abstract: Disclosed is an ML attack resisting method for a strong PUF. Response signals generated by applying multiple sets of different challenge signals to a strong PUF are used as information to be encrypted, and are put in order to form a plaintext matrix. Then a matrix multiplication operation is performed on two plaintext matrixes to generate a ciphertext matrix. Next, elements in a transform matrix obtained by performing binary transformation on the ciphertext matrix are used as final responses, which are in one-to-one correspondence with original challenge signals and are used as final CRPs of the matrix-encrypted strong PUF.

Abstract: A reliable multi-information entropy PUF for Internet of Things security includes a control circuit, a data register, 128 glitch generation circuits, a 128-to-1 multiplexer, and a Schmidt glitch sampling module. The control circuit controls the data register to generate a square signal, the 128 glitch generation circuits to generate glitch signals to be output and the 128-to-1 multiplexer to select the glitch signals to be output. The Schmidt glitch sampling module samples the glitch signals to obtain PUF response outputs. Each glitch generation circuit generates a glitch signal by means of a fully symmetrical structure. The Schmidt glitch sampling module comprises a first PMOS transistor, a second PMOS transistor, a third PMOS transistor, a fourth PMOS transistor, a first NMOS transistor, a second NMOS transistor, a third NMOS transistor, a fourth NMOS transistor, a buffer module and a D flip-flop.

Abstract: The present invention discloses a bidirectional collapse-proof damper with a macroscopic NPR structure and a bridge structure having the same, comprising a sleeve and a sliding rod; by adding a structure of a reducing part and a limiting body, a sliding gap exists between both ends of the limiting body and both inner ends of the reducing part; the rod body is connected with the inner side wall of the sleeve through an elastic element; the limiting body and the rod body can realize bidirectional slip in the sleeve, which have multi-level seismic performance.

Abstract: The disclosure is a medical disease feature selection method based on an improved salp swarm algorithm. The improved salp swarm algorithm is used to optimize a feature selection problem, the accuracy of the mentioned method is estimated by means of a transfer function and classification by a K-nearest neighbor algorithm, and the salp swarm algorithm is improved by using a self-adapted control parameter and an elite grey wolf ruling policy, so that it helps the algorithm avoid premature convergence in the optimization process and jump out of local optimum, thereby achieving a target of the algorithm with the smallest selected feature quantity and the highest classification precision. The method has the advantages of high rate of convergence, higher classification precision and better robustness.

Abstract: The invention discloses a multi-threshold segmentation method for medical images based on an improved salp swarm algorithm. A two-dimensional histogram is established by means of a grayscale image of a medical image and a non-local mean image, then a salp swarm algorithm is used to determine thresholds selected by a Kapur entropy-based threshold method, and the salp swarm algorithm is improved and mutated by an individual-linked mutation strategy during the threshold selection process to avoid local optimization, so that the segmentation effect on the medical image is optimized; and the method has the advantages of good robustness and high accuracy.

Abstract: An experimental setup for measuring the vacuum degree and pore pressure at a point of soil mass in vacuum consolidated state, including a connecting tube, the connecting tube includes an upper water storage tube, a middle tube, the middle tube is loaded with an upper experimental soil mass, the lower tube is loaded with a lower experimental soil mass, a water storage chamber is connected to a pumping mechanism, an intermediate inner chamber is connected to a negative pressure vacuum gauge, the inlet conduit is connected to a negative pressure vacuum gauge. Additionally, the present invention provides a test operation method. The device measures the vacuum degree of upper part of experimental soil mass by observing the reading in the negative pressure vacuum gauge.

Abstract: A reaction of azacyclopropane derivative with elemental selenium and TMSCN to construct a selenium-containing heterocycle under metal-free and additive-free conditions is provided. The new strategy features no metal participation, no additive promotion, a wide substrate selection range and a good functional group compatibility, and provides an efficient and green approach to constructing a variety of selenium-containing heterocyclic compounds in a highly concise way.

Abstract: The present disclosure provides a leakage measurement error compensation method based on cloud-edge collaborative computing, implemented on a communication network formed by interconnection between a leakage current edge monitoring terminal and a power consumption management cloud platform, and including the following steps: monitoring, by the leakage current edge monitoring terminal, leakage current data, and sending the leakage current data to the power consumption management cloud platform; iteratively training, by the power consumption management cloud platform, a pseudo-leakage compensation model by using the received leakage current data, continuously updating pseudo-leakage model parameters, and feeding the pseudo-leakage model parameters back to the leakage current edge monitoring terminal; and processing, by the leakage current edge monitoring terminal, the leakage current data according to the pseudo-leakage compensation model parameters, so as to eliminate the influence of a pseudo-leakage phenomen

Abstract: The invention relates to a Novosphingobium sp. SJB007 and an application thereof in removal of phosphorus from wastewater, belonging to the technical field of environmental microorganisms. One aspect of the invention provides a Novosphingobium sp. SJB007 with an access number of CGMCC (China General Microbiological Culture Collection Center) No. 21177. Another aspect of the invention provides an application of the Novosphingobium sp. SJB007 in removal of phosphorus from wastewater. The efficient phosphorus-accumulating strain Novosphingobium sp. SJB007 provided by the invention has a high removal rate of more than 97% when the concentration of phosphorus in the wastewater is 10-30 mg/L under an appropriate condition.

Abstract: A method for assembling a dual-head pulling rod involves attaching pulling heads to two ends of a rod body through threaded connection using a system that includes a foundation, on which a rod dispensing device, an inclined guiding plate, a conveying flap, a head dispensing device, a head mounting unit, a clamping device, an assembling device and a V-shaped output channel are provided. The inclined guiding plate is inclined and uses its ramp to guide a rod body falling thereon. The conveying flap is swingable between an input position and an output position. The conveying flap at the input position receives the rod body coining from the inclined guiding plate and outputs the rod body to the clamping device.

Abstract: A strong and weak hybrid PUF circuit comprises N switch units and an arbiter. Each switch unit consists of two delay modules and two 2:1 multiplexers. The N switch units constitute two completely symmetrical delay paths. Each delay module consists of six stages of delay cells. During the operating process, a transmission signal selects a turn-on path of the corresponding 2:1 multiplexers according to activation signals; the switch units in the PUF circuit are in a valid state (if the delay modules are turned on) or in an invalid state (if the delay modules are not turned on) according to whether the delay modules are turned during the operating process; and the strong and weak hybrid PUF circuit can be flexibly configured to be of two different types (a strong PUF circuit and a weak PUF circuit) according to changes of the Hamming weight of input activation signals.

Abstract: A control flow attacks based on return address signatures comprises: using a return address as a push return address when a response is given to an interrupt service routine; generating an encrypted push return address by an XOR encryption circuit by means of an n-bit binary key generated by a pseudo random number generator; then, generating a push_address signature value by an MD algorithm signature circuit; when the response to the interrupt service routine is over, reading an n-bit binary address out of a stack to serve as a pop return address; generating an encrypted pop return address by the XOR encryption circuit; generating a pop address signature value by the MD algorithm signature circuit; comparing the push_address signature value with the pop address signature value; and determining whether or not a data processor is under a control flow attack according to a comparison result.

Abstract: The present invention provides an optimizing growth method for improving quality of MOCVD epitaxial thin films, including the following method: step 1, putting a substrate and a thin film A to a reaction chamber of an MOCVD equipment; and feeding a compound containing an element X as an X source under the condition that the reaction chamber is filled with H2; configuring a temperature, reaction chamber pressure and deposition time within a parameter range where the gaseous compound can decompose X atoms; pre-depositing an X atomic layer on a surface of the substrate or the thin film A; the X atomic layer is adsorbed on the substrate or thin film A at this time; and the X atomic layer can be reacted with other compounds to generate a thin film B component in the follow-up process, or can directly form a thin film B component with the thin film A.

Abstract: The present invention provides an online laser leveling detection method of a 3D printer. The method comprises: (1), arranging a bar-shaped triangular reflecting prism and a bar-shaped photoelectric receiver; (2), fixedly mounting a laser emitter and a plane mirror on the side face of a printer head; (3), with the aid of a detection laser beam, fine tuning the mounting azimuths of an X-axis guide rail, a Y-axis guide rail, and the printer head till the motion levelness of the printer head is adjusted to meet requirements of the design accuracy of the printer; (4), with the aid of the detection laser beam, fine tuning the mounting azimuth of a printing platform till the mounting levelness of the printing platform is adjusted to meet the requirements of the design accuracy of the printer; (5), starting the 3D printing program; (6), in the printing process, detecting in real time whether a nozzle of the printer head generates faults including material blockage, shortage, and breakage.

Abstract: A system synchronization method includes: connecting synchronization modules of a plurality of devices together through a synchronization bus. The synchronization modules include a signal generation module, a switch control module, a synchronization bus monitoring module, and a switch S1. A signal output terminal of the signal generation module is connected to a first terminal of the switch S1, and a timing overflow terminal of the signal generation module is connected to the switch control module configured to control the switch S1. The switch control module is connected to the synchronization bus monitoring module. A second terminal of the switch S1 is connected to the switch control module and the synchronization bus monitoring module. The system synchronization method has the advantages of simple structure, low cost, high reliability, and good practicability.

Abstract: A device for extracting polysaccharide from acaudina molpadioides is provided, which includes a mixing box, a blocking cover, a feed pipe group, a discharge pipe, a bottom plate, a side plate, a first motor, a first transmission shaft, two drive shafts, a first circular gear, two second circular gears, two rotary discs, two connecting frame groups, two semiarc rotary discs, a slide bar, a stop collar, a fixed link, a baffle, a first bushing group and a first sleeve spring group. A top side wall and a rear lower side of the mixing box are communicated with the feed pipe group and the discharge pipe, respectively. Front side and rear sides of the slide bar are longitudinally connected with multiple first engaging teeth. Both the two semiarc rotary discs are connected with multiple second engaging teeth. The fixed link is connected between the stop collar and the slide bar.