Multimode Mechanism Research Articles

A Generalized Information Security Model SOCMD for CMD Systems

As a new security defense theory, Cyberspace mimic defense (CMD) provides an architecture named Dynamic heterogeneous redundancy (DHR) to enhance the defense level of system security. Due to the new dynamic defense mechanism DHR introduced in CMD systems, traditional security modelling and analysis methods can hardly be used for them. In this paper, we propose a Security ontology-based modelling method for CMD systems (SOCMD), which uses ontology to represent DHR components and to define their inner relationships. SOCMD also connects information components including DHRs with security vulnerabilities, threats and attackers in cyberspace. Next, attacking rules, multi-mode arbitration mechanism and combination rules are designed with SOCMD for CMD systems and a new logical-checking method is proposed to make judgement about the security state of SOCMD. Finally, different use cases and performance tests are developed to demonstrate the application process for the model and to verify the validity of our method.

Blockchain-Based Safety Management System for the Grain Supply Chain

In recent years, various food-safety issues have aroused public concern regarding safety in the food supply chain. Since grains are closely linked to human life and health, it is necessary to effectively manage information in the grain supply chain. The grain supply chain is characterized by a long life cycle, complex links, various hazards, and heterogeneous information sources. Problems with traditional traceability systems include easy data tampering, difficult hazardous-material information management, the “information isolated island” problem, and low traceability efficiency in the whole supply chain. Blockchain is a distributed computing paradigm characterized by decentralization, network-wide recording, security, and reliability. As such, it can reduce administrative costs and improve the efficiency of information management. Based on literature research and a field investigation of wheat-processing enterprises in Shandong Province, We analyze the operation process of grain supply chain. This study, therefore, proposed a new system architecture in the entire grain supply chain based on blockchain technology and designed a multimode storage mechanism that combines chain storage. This prototype system was tested and verified using actual cases and application scenarios. Compared to traditional systems, the proposed system is characterized by data security and reliability, information interconnection and intercommunication, real-time sharing of hazardous-material information, and dynamic and credible whole-process tracing. As such, this system is highly significant and has reference value for guaranteeing food quality and safety-process traceability.

A Micro Piezoelectric Motor With Multiple Excitation Modes and Methods

To widen the performance of piezoelectric motors, this paper demonstrates a micro piezoelectric motor having multiple driving ways. The stator includes a hollow polygon bar and two groups of PZT plates. PZT plates are symmetrically bonded onto a brass base, and used to actuate the vibration modes of the stator. The symmetrical design enables the motor to operate in two types of vibration modes. The working modes are the second/third-order in-plane bending modes, and can be excited by different ways. Elliptical motion of stator surface points is generated by superposition of two bending modes with the same order. To investigate the feasibility of multi-mode and multi-motivation mechanisms, vibration behaviors of stator driving particles are simulated using ANSYS software. The structural parameters of the stator are strictly designed to harmonize the eigenfrequencies of the vibration modes. The calculated results reveal that the motor performance can be adjusted by selecting different operating modes and excitation ways. The motor performances under various excitation ways and driving modes are also investigated experimentally to validate the proposed design. The dimension of the fabricated prototype motor is 8.3 mm$\times 7.2$ mm$\times 15.0$ mm. The maximum torques are respectively 8.3 cN$\cdot \text{m}$ and 13.3 cN$\cdot \text{m}$ under single-phase and two-phase excitation voltages, when the motor operates in the second-order bending modes. The corresponding no-load speeds are respectively 40 rpm and 47 rpm. The maximum torque and speed under the third-order bending modes are much smaller than that under the second-order bending modes.

State of the Art of Multi-mode Mechanisms

State of the Art of Multi-mode Mechanisms

A New Mathematical Method to Study the Singularity of 3-RSR Multimode Mobile Parallel Mechanism

In the process of parallel mechanism design, it is difficult to avoid the singularity, especially in the mobile parallel mechanism. Therefore, a new mathematical method to study the singularity of multimode mobile parallel mechanism is proposed. In this paper, the singularity of 3-RSR parallel mechanism (PM) is analyzed by using reciprocal screw methods and linear geometry theory from two aspects of fixed mode and all-attitude multiple motion modes. Specifically, the complete Jacobian matrix of the PM is obtained by using the screw theory, and the reciprocal screw of each branch is expressed with algebraic method and geometric drawing method. Furthermore, the singularity of the PM can be obtained by analyzing the reciprocal screw correlation and using the spatial linear geometry theory. Finally, we analyze the singular configuration of the PM under various modes, which provide theoretical guidance for the gait planning of the multimode mobile PM and will be useful for the selection of mechanism drive and time-sharing control.

Ternary thiol-ene photopolymerization for facile preparation of ionic liquid-functionalized hybrid monolithic columns based on polyhedral oligomeric silsesquioxanes

A simple thiol-ene photopolymerization approach was developed for the rapid preparation of ionic liquid-functionalized hybrid monolithic column based on polyhedral oligomeric silsesquioxane (POSS). “One-pot” polymerization was realized in the UV-transparent fused-silica capillary by using octanethiol, 1-allyl-3-methylimidazolium hexafluorophosphate as functional monomers and methacryl-substituted POSS as a crosslinker. The thiol-vinyl-methacrylate ternary system uniquely exhibits a mixed step-chain growth polymerization regime that combining the thiol-ene reaction and free-radical reaction mechanisms, which provides a simple route to prepare novel POSS-based functionalized hybrid monoliths. The pore property, permeability, and electroosmotic flow (EOF) of the hybrid monoliths can be tailored by proper adjustment of the feeding composition and initiation condition. Morphologic and spectroscopic characterizations of monolithic columns clearly indicate that utilization of the photo-initiated approach in thiol-vinyl polymerization can generate a more homogeneous porous structure, smaller domain size and higher column efficiency (53,800–60,300 plates/m for alkylbenzenes) than the thermally-initiated one (32,800–49,300 plates/m). Significant improvements in mechanical stability, anti-swelling property and tailorability of hybrid polymer were achieved in a simple manner, owing to the photopolymerization of rigid nanoscale POSS units and imidazolium-based ionic liquids in ternary thiol-vinyl system for the first time. The resulting hybrid monolith possessed controllable EOFs at pH values from 2 to 10, and showed a multimode separation mechanism in capillary electrochromatography, including π-π interaction, ion exchange, electrophoretic migration, electrostatic and hydrophobic interaction. Satisfactory separation ability was achieved for the analysis of different types of small molecules.

A Novel Method for Constructing Multimode Deployable Polyhedron Mechanisms Using Symmetric Spatial Compositional Units

A novel construction method is proposed to construct multimode deployable polyhedron mechanisms (DPMs) using symmetric spatial RRR compositional units, a serial kinematic chain in which the axes of the first and the third revolute (R) joints are perpendicular to the axis of the second R joint. Single-loop deployable linkages are first constructed using RRR units and are then assembled into polyhedron mechanisms by connecting the single-loop linkages using RRR units. The proposed mechanisms are over-constrained and can be deployed. The prism mechanism constructed using two Bricard linkages and six RRR chains has one degree-of-freedom (DOF). When removing three of the RRR chains, the mechanism will have one additional 1-DOF motion mode. The DPMs based on 8R and 10R linkages also have multiple modes, and several mechanisms have variable-DOF. The DPMs can switch among different motion modes through transition positions. Prototypes are 3D-printed to verify the feasibility of the mechanisms.

Survey of connected automated vehicle perception mode: from autonomy to interaction

For enhancing the intelligence of urban traffic, connected automated vehicle (CAV) is recognised as the leading technology in the near future. With on-board sensors and communication devices, status of the vehicles can be obtained to better coordinate the traffic. However, the limited environmental perception range cannot lead to the best efficiency of the global urban traffic. In this study, a three-step evolution strategy of the CAV perception mode is proposed, from autonomous perception to interactive perception to networked perception. Key technologies in these three steps are studied. In autonomous perception, vehicle positioning and dynamic target tracking approaches are proposed. In interactive perception, a reliable multi-mode information exchange mechanism is studied. Finally, a new traffic big data storage and advanced analytics solution in networked perception is introduced. Related experiments about the above key issues are designed, implemented, and verified based on the hardware platform, open source dataset, and cloud platform, respectively. The results show that the positioning distance root mean square achieves 3.9 m, object tracking speed reaches 30fps, and communication average packet loss rate is 2%. As can be seen from testing and simulation results, our proposed approaches can meet technical requirements and support environment perception mode evolution of CAV.

Multi-mode responses, rivulet dynamics, flow structures and mechanism of rain-wind induced vibrations of a flexible cable

We successfully excite the multi-mode rain-wind induced vibrations (RWIVs) of a flexible stay cable in a wind tunnel by guiding water rivulets along the cable surface. The first, second and third mode RWIVs are excited respectively by increasing the incoming wind speed. The movement of upper rivulet during the first, second and third mode RWIVs are recorded with a high-speed camera. By employing a computer vision based recognition technique, the upper-rivulet dynamics of different modes of RWIVs are recognized and analyzed. The wake flow structures around the dry cable and the cable suffering from RWIVs are measured by using a particle image velocimetry (PIV) system. Experiment results show that the oscillation frequency of the upper rivulet is synchronized with the cable vibration frequency for the first, second and third mode RWIVs. Based on experiment results, bubble burst is proposed as a possible mechanism for the excitation of RWIVs.

Effective multi-mode routing mechanism with master-slave technique and reduction of packet droppings using 2-ACK scheme in MANETS

Effective multi-mode routing mechanism with master-slave technique and reduction of packet droppings using 2-ACK scheme in MANETS

Design of a Compliant Gripper With Multimode Jaws

This paper presents the design of a multimode compliant gripper, using the singularities of the four-bar mechanism with equilateral links. The mobility of the compliant gripper can be reconfigurable to grasp a variety of shapes or adapt to specific requirements. The compliant gripper is a compact and two-layer structure. Two linear actuators are required to enable the multiple operation modes, by the conversion of two pairs of slider-crank mechanisms. A multimode compliant four-bar mechanism is first presented and kinematically analyzed. The design and the kinetostatic modeling of the resulting compliant gripper are then performed. Finally, the analysis of the reconfigurable compliant gripper under different actuation schemes is carried out, including the comparison of the results obtained from analytical modeling, finite element analysis (FEA), and experimental testing.

Multi-axial damage and failure of medical grade carbon fibre reinforced PEEK laminates: Experimental testing and computational modelling.

Orthopaedic devices using unidirectional carbon fibre reinforced poly-ether-ether-ketone (PEEK) laminates potentially offer several benefits over metallic implants including: anisotropic material properties; radiolucency and strength to weight ratio. However, despite FDA clearance of PEEK-OPTIMA™ Ultra-Reinforced, no investigation of the mechanical properties or failure mechanisms of a medical grade unidirectional laminate material has been published to date, thus hindering the development of first-generation laminated orthopaedic devices. This study presents the first investigation of the mechanical behaviour and failure mechanisms of PEEK-OPTIMA™ Ultra-Reinforced. The following multi-axial suite of experimental tests are presented: 0° and 90° tension and compression, in-plane shear, mode I and mode II fracture toughness, compression of ±45° laminates and flexure of 0°, 90° and ±45° laminates. Three damage mechanisms are uncovered: (1) inter-laminar delamination, (2) intra-laminar cracking and (3) anisotropic plasticity. A computational damage and failure model that incorporates all three damage mechanisms is developed. The model accurately predicts the complex multi-mode failure mechanisms observed experimentally. The ability of a model to predict diverse damage mechanisms under multiple loading directions conditions is critical for the safe design of fibre reinforced laminated orthopaedic devices subjected to complex physiological loading conditions.

Motion Analysis and Optimization Design of Back Support Mechanism Based on Pose Adjustment

In order to realize stable and safe operation of multi-mode bed back support mechanism, various angle adjustment mechanisms are studied and analyzed. An angle adjustment mechanism using a guide mechanism is proposed. The function of back support is achieved by using an electric push rod. A model of the back support mechanism was built. Based on the analysis of the geometric relationship and mechanical model of the back support mechanism, the optimal solution of the fixed position of the electric actuator was solved by using MATLAB. Dynamic simulation, performed by SOLIDWORKS Motion, determine the optimal stroke of the electric actuator. Finite element analysis, performed by SOLIDWORKS Simulation, verify the feasibility of the back support mechanism. The simulation results show that using the back support mechanism of the guide rod mechanism reduces the load of the load beam, improves the safety of the back support mechanism, and stabilizes the back support process.

Reconfiguration Analysis of Multimode Single-Loop Spatial Mechanisms Using Dual Quaternions

Although kinematic analysis of conventional mechanisms is a well-documented fundamental issue in mechanisms and robotics, the emerging reconfigurable mechanisms and robots pose new challenges in kinematics. One of the challenges is the reconfiguration analysis of multimode mechanisms, which refers to finding all the motion modes and the transition configurations of the multimode mechanisms. Recent advances in mathematics, especially algebraic geometry and numerical algebraic geometry, make it possible to develop an efficient method for the reconfiguration analysis of reconfigurable mechanisms and robots. This paper first presents a method for formulating a set of kinematic loop equations for mechanisms using dual quaternions. Using this approach, a set of kinematic loop equations of spatial mechanisms is composed of six polynomial equations. Then the reconfiguration analysis of a novel multimode single-degree-of-freedom (1DOF) 7R spatial mechanism is dealt with by solving the set of loop equations using tools from algebraic geometry. It is found that the 7R multimode mechanism has three motion modes, including a planar 4R mode, an orthogonal Bricard 6R mode, and a plane symmetric 6R mode. Three (or one) R (revolute) joints of the 7R multimode mechanism lose their DOF in its 4R (or 6R) motion modes. Unlike the 7R multimode mechanisms in the literature, the 7R multimode mechanism presented in this paper does not have a 7R mode in which all the seven R joints can move simultaneously.

Oleanolic–bioenhancer coloaded chitosan modified nanocarriers attenuate breast cancer cells by multimode mechanism and preserve female fertility

Addressing multidrug resistant stage of breast cancer is an impediment for chemotherapy. Moreover, breast cancer chemotherapy has potential enduring confrontations i.e. related toxicity including effect on fertility of young female patients. The co-delivery of polyphenolic bio-enhancers with oleanolic acid in chitosan coated PLGA nanoparticles was designed for oral delivery with enhanced antitumor effect consecutively preserving the female fertility. The optimized oleanolic- bio-enhancer nano formulation CH-OA-B-PLGA with particle size was 342.2±3.7nm and zeta potential of 34.2±3.1mV was capable of lowering viability in MDAMB 231 cell line 16 times than OA. Further, mechanistic studies in MDAMB-231 cells revealed that CH-OA-PLGA induces apoptosis by mitochondrial membrane disruption; follows ROS mediated and caspase dependent apoptosis. The antitumor effect studied in 4-T1 induced Balb/c mice mammary tumor model displayed augmented antitumor potency by CH-OA-B-PLGA in comparison to OA. In the in vivo toxicity on Sprague–Dawley rat model, CH-OA-B-PLGA significantly displayed the safe profile and also preserves fertility in female rats.The experiment result suggests co-delivery of oleanolic acid with bio-enhancers as a breakthrough for developing safe chemotherapy for hormone independent breast cancer therapy countering the toxicity issues.

Importance of adaptive multimode lubrication mechanism in natural synovial joints

The superior tribological performance in natural synovial joints with low friction and minimal wear appears to be actualized by not single lubrication mode but the synergistic combination of various modes from the fluid film lubrication to boundary lubrication corresponding to the severity of rubbing conditions. We have conducted the biphasic finite element analysis and some experimental studies for articular cartilage to elucidate this ingenious lubrication mechanism from the viewpoint of the adaptive multimode lubrication mechanism. In this paper, the effectiveness of different lubrication modes such as biphasic, boundary, gel-film and hydration lubrication particularly at low speed conditions is discussed.

Simple antenna structure enabling the simultaneous excitation of two different polarisation and radiation modes

A simple antenna structure able to simultaneously generate two different polarisation and radiation modes is proposed. In addition to a good impedance matching all over multiple bands, antennas based on the proposed geometry can exhibit a linearly polarised omnidirectional radiation pattern at lower frequencies, allowing the communication in any azimuthal direction, and a circularly polarised directive diagram at higher frequencies that enables links for satellite-based applications. These characteristics together with a low-profile, a light weight and a robust and easy-to-realise structure make the antenna an effective candidate for integration into vehicles. The antenna multimode radiation mechanism is explained in detail. In order to demonstrate its effectiveness, the proposed structure is applied to the design of two different antennas for practical applications. The performances of these antennas are assessed by means of numerical simulations and validated through experimental measurements.

Superior lubricity in articular cartilage and artificial hydrogel cartilage

In healthy natural synovial joints, the extremely low friction and minimum wear are maintained by their superior load-carrying capacity and lubricating ability. This superior lubricating performance appears to be actualized not by single lubrication mode but by synergistic combination of multimode mechanisms such as fluid film, biphasic, hydration, gel film and/or boundary lubrication. On the contrary, in most artificial joints composed of ultra-high molecular weight polyethylene against metal or ceramic-mating material, boundary and/or mixed lubrication modes prevail and thus local direct contact brings down high friction and high-wear problems. To extend the durability of artificial joint, the reduction in friction and wear by improvement in lubrication mechanism is required as an effective design solution. In this paper, at the start, the mechanism of superior lubricity for articular cartilage is examined from the viewpoints of biphasic and boundary lubrication mechanism. Subsequently, the proposal of biomimetic artificial hydrogel cartilage is put forward to improve the lubricating modes in artificial joints. The tribological behaviours in two kinds of poly(vinyl alcohol) hydrogels are compared with that of natural cartilage. The importance in lubrication mechanism in artificial hydrogel cartilage is discussed.

Coupling interaction between a single emitter and the propagating surface plasmon polaritons in a graphene microribbon waveguide

The coupling interaction between an individual optical emitter and the propagating surface plasmon polaritons in a graphene microribbon (GMR) waveguide is investigated by numerical calculations, where the emitter is situated above the GMR or in the same plane of the GMR. The results reveal a multimode coupling mechanism for the strong interaction between the emitter and the propagating plasmonic waves in graphene. When the emitter is situated in the same plane of the GMR, the decay rate from the emitter to the surface plasmon polaritons increases more than 10 times compared with that in the case with the emitter above the GMR.

Related flavonoids cause cooperative inhibition of the sarcoplasmic reticulum Ca2+ ATPase by multimode mechanisms

Flavonoids are group of plant-derived hydroxylated polycyclic molecules found in fruit and vegetables. They are known to bio-accumulate within humans and are considered to have beneficial health effects, including cancer chemoprotection. One mechanism proposed to explain this is that they are able to induce apoptosis in cancer cells by inhibiting a variety of kinases and also the Ca²⁺ ATPase. An investigation was undertaken with respect to the mechanism of inhibition for three flavonoids: quercetin, galangin and 3,6 dihydroxyflavone (3,6-DHF). Each inhibited the Ca²⁺ ATPase with K(i) values of 8.7, 10.3 and 5.4 μM, respectively, showing cooperative inhibition with n ~ 2. Given their similar structures, the flavonoids showed several differences in their mechanisms of inhibition. All three flavonoids stabilized the ATPase in the E₁ conformation and reduced [³²P]-ATP binding. However, both galangin and 3,6-DHF increased the affinity of Ca²⁺ for the ATPase by decreasing the Ca²⁺-dissociation rate constant, whereas quercetin had little effect. Ca²⁺-induced changes in tryptophan fluorescence levels were reduced in the presence of 3,6-DHF and galangin (but not with quercetin), indicating that Ca²⁺-associated changes within the transmembrane helices are altered. Both galangin and quercetin reduced the rates of ATP-dependent phosphorylation and dephosphorylation, whereas 3,6-DHF did not. Modelling studies suggest that flavonoids could potentially bind to two sites: one directly where nucleotides bind within ATP binding site and the other at a site close by. We hypothesize that interactions of these two neighbouring sites may account for both the cooperative inhibition and the multimode mechanisms of action seen with related flavonoids.