106 results about "Microkernel" patented technology

A system and method for real-time or near real-time multilingual language transformation in telecommunications environments using distributed artificial intelligence (Al). The system includes at least one processor configured to instantiate a plurality of Al agents, each corresponding to a user in a communication session, and to manage their operation via an Al-agent runtime adapter comprising a microkernel agent manager and a virtual machine layer. A language model abstraction layer enables access to language models and Al algorithm libraries through publish-subscribe interfaces. The system supports contextual transformation of speech based on user profile data such as sentiment, emotional tone, and cultural background. Execution can occur on telecommunication-class switches, edge devices, or general-purpose computing hardware. Al agents operate asynchronously, access shared or private memory, and produce personalized, bidirectional linguistic output. The architecture supports secure, scalable deployment across heterogeneous devices and networks.

The invention relates to the technical field of artificial intelligence compilers, in particular to an AI compiler and compiling method based on a multi-level intermediate representation framework, and the compiler comprises a high-level semantic retention layer which converts models of different AI frameworks into Lalg-on-Tensor IR intermediate representations; the hardware perception optimization layer comprises a tensor packaging and propagation module which is used for performing block packaging, layout propagation and folding of redundant packaging / unpackaging operation on the input tensor; the dynamic partitioning module is used for automatically selecting the partitioning size based on the cache capacity and the core number of the target hardware; the microkernel fusion module is used for fusing matrix multiplication, bias addition and an activation function into a single composite operator; and the microkernel collaboration layer is in butt joint with the hardware acceleration library through the XSMM dialect to generate a target hardware code. The hardware perception optimization layer can perform optimization according to different hardware characteristics, so that codes generated by the compiler can better adapt to target hardware, and the hardware utilization rate is improved.

The invention discloses a method for communication between a user program and a virtual machine on a microkernel Hypervisor, the microkernel Hypervisor is provided with two shared memory areas, the shared memory area 1 is accessed by the user program and a root service Rootserver, the shared memory area 2 is accessed by the Rootserver and the virtual machine, the user program writes communication request data with the virtual machine into the shared memory area 1, and the user program writes communication request data with the virtual machine into the shared memory area 2. The method comprises the following steps that a VMM sub-thread is used as a shared memory area 1, a Rootserver is notified through inter-process communication, the Rootserver reads communication request data from the shared memory area 1, the communication request data is written into a shared memory area 2 after being analyzed by the VMM sub-thread, a system calls a syscale to transmit a communication request to a kernel, the kernel injects virtual interrupt into a virtual machine, and the virtual machine sends the communication request to the Rootserver. And an interrupt processing program of the virtual machine processes the communication request and writes a processing result into the shared memory area 2, then the processing result is returned to the Hypervisor through the Hypercall, and a Rootserver of the Hypervisor feeds back the processing result to a user program through the IPC. The method is designed for the microkernel Hypervisor environment, and the overall performance and efficiency of the embedded virtualization system are improved.

The invention relates to an electric power mobile application security protection method based on a swan gap microkernel, which comprises the following steps of: S1, establishing a hardware trust root, and storing a device root key and a certificate chain by utilizing a non-tampering storage area built in a chip; s2, establishing a complete trusted boot chain based on a hardware root of trust, and verifying the integrity and credibility of the next layer by each layer from Bootloader to a swan microkernel and then to an application program; s3, constructing a triple authentication system based on user identity, equipment identity and biological characteristics, and performing user authentication; s4, according to a user authentication result, realizing fine-grained authority control based on an RBAC model and ABAC, and ensuring that authority check can be executed during resource access every time by utilizing an IPC security mechanism of a swan micro kernel; and S5, creating an independent execution environment for each power application according to the process isolation capability of the swan microkernel, and ensuring that memories among the applications cannot be mutually accessed through virtual address space isolation. The reliability of power mobile application safety protection is effectively improved.

The invention belongs to the technical field of information security, and relates to an endogenous security OS construction method and device based on intelligent agent and control computing, and the method comprises the steps: constructing an underlying security base based on a hardware trusted root and a microkernel; based on the bottom-layer security base, defining and deploying a hierarchical multi-intelligent agent with a specific function; establishing a multi-agent communication and interaction protocol stack for the multi-intelligent agent; based on a multi-agent communication and interaction protocol stack, an intelligent collaborative scheduling algorithm oriented to multi-objective optimization is developed; an endogenous security mechanism integrating active defense and passive response; and carrying out full-life-cycle security situation assessment on the endogenous security operation system. Dynamic intrusion detection can be carried out, an intrusion detection system (IDS) based on machine learning is deployed, a normal behavior mode of an intelligent agent is learned, and abnormal tampering behaviors, DoS attacks, communication anomalies and the like are identified.

The invention discloses a mobile storage security access control system and method based on a microkernel architecture, and relates to the technical field of data storage security. The system comprises a host end and a mobile storage device end. And the host end is provided with a special device driver and is used for sending the generated authentication data and the storage access instruction to the mobile storage device end through the virtual storage front-end device created by the special device driver. And the mobile storage device end is deployed with an operating system based on a microkernel architecture, creates a virtual storage rear-end device corresponding to the virtual storage front-end device, and is used for performing host identity and capability verification on the authentication data received by the virtual storage rear-end device, and receiving and executing a storage access instruction from the host end after the verification is passed. Communication connection is established between the virtual storage front-end device and the virtual storage rear-end device through a USB bus. According to the system, active and fine-grained power control of access to the mobile storage equipment end is realized.

Embodiments of the present application provide a distributed scheduling method, apparatus and system for a deterministic task, for use in scheduling an on-cloud task. A cloud comprises a management node and computing nodes. The method comprises: on the basis of a configuration of a received task and resources of the computing nodes, the management node schedules the task to a computing node meeting the configuration, the configuration comprising resource demands meeting a deterministic constraint of the task, and the resource demands comprising a computing resource demand and a transmission resource demand; and on the computing node to which the task is scheduled, the management node schedules the task to a corresponding running capsule on the basis of the configuration, the resource of the running capsule meeting the configuration, and an elastic microkernel of each computing node being used for allocating a resource to the running capsule on the computing node. The technical solution of the embodiments of the present application achieves the scheduling of an on-cloud deterministic task, and supports the deterministic scheduling of the task in various scenarios, such as virtual machines, containers, processes and threads.

The invention relates to the technical field of industrial automatic control, and discloses an industrial configuration software cross-platform cooperative control method and system based on a swan gap, which realize flexible initialization and dynamic task distribution of a control terminal by fully utilizing distributed communication and microkernel characteristics of a swan gap system. Through structured analysis and task graph construction of a configuration control model, granularity recombination and task parallel execution of a control process are supported; a task terminal recommendation mapping table is further generated in combination with the execution requirement of the control task and the terminal capability label information, and the adaptation matching degree of the control task and the execution terminal is effectively improved; and meanwhile, a distributed cooperative channel is constructed, a communication binding channel between the master control terminal and the slave control terminal is established, and a guarantee is provided for rapid scheduling and execution of tasks. Compared with the prior art, the heterogeneous compatibility, the task scheduling efficiency and the protocol adaptation flexibility can be remarkably improved, and the method is suitable for high-complexity and multi-terminal collaborative industrial automation control scenes.

The invention discloses a whole-body collaborative voice control system and method for a humanoid robot, relates to the technical field of robots, and aims to solve the problems of semantic understanding superficial layer, action planning localization and safety control lagging in existing humanoid robot voice control. Through closed-loop cooperation of the multi-mode intention understanding module, the whole-body action planning module, the dynamic balance security arbiter and the microkernel security scheduler, a unified control architecture is constructed. According to the system, natural language instructions are deeply analyzed into whole-body motion constraints through a semantic-action mapping knowledge base, anthropomorphic collaborative motion trails are generated, pre-security verification is conducted through a boundary model based on Lyapunov stability, and finally hard real-time execution and full-cycle security guarding are achieved through a microkernel security scheduler. According to the method, direct conversion from natural language to safe, stable and anthropomorphic whole-body motion is realized, and the task execution capability and the interaction naturalness of the humanoid robot in a complex scene are remarkably improved.

The invention relates to a hot update control method and system for an industrial PLC (Programmable Logic Controller) of a microkernel operating system, belonging to the field of industrial controllers. A shadow instance is created by an isolated address space and is bound with a shadow I / O (Input / Output) mirror image and a shadow communication stack; capturing a containment point in the scanning period, wherein the containment point is located between input sampling completion and output submission; acquiring running state information from the current network instance, converting the running state information, and transmitting the converted running state information to the shadow instance; pre-operating the shadow instance in the isolation channel in an accelerated or constant-speed manner, and switching the I / O channel from the current network instance to a shadow I / O mirror image of the shadow instance at the next restraint point if the verification is passed; and continuing to run in parallel for a certain period, unloading the old instance if the continuous running is qualified, and executing rollback if an exception occurs. Depending on a microkernel operating system, shadow instances are drilled and switched under the controlled priority, the real-time performance and certainty are met, the time delay defect of periodic gap switching is overcome, and updating and switching are completed in a single scanning period or a plurality of scanning periods in an atomic mode.

The invention belongs to the field of network security, and relates to a method and a device for constructing a network security operating system, electronic equipment and a storage medium, and the method comprises the following steps: constructing an autonomously controllable improved microkernel infrastructure; based on the microkernel infrastructure, constructing a full-stack layered security control computing architecture base; constructing intelligent agent components, and deploying a multi-intelligent agent collaborative protection component system; integrating trusted computing and an integrity measurement verification system; performing dynamic adaptation and execution of multiple security policies; and a standardized safety evaluation and adaptive optimization closed loop is established. A trusted computing base is cut from a design source, so that the probability of occurrence of high-risk vulnerabilities is reduced; the real-time defense that the threat is changed and the strategy is changed is realized, and the blind area of the static strategy in resisting the unknown threat is made up; the malicious codes can be blocked before running, and the post passive situation that traditional security software only depends on a feature library for searching and killing is broken; and the contradiction between security capability solidification and threat dynamic evolution is fundamentally solved.

The invention relates to an operating system environment construction technology, and discloses an ARM (Advanced RISC Machines) processor-oriented micro-kernel operating system confidential computing environment construction method, which is characterized in that a hierarchical system architecture is constructed, a virtual machine monitor and a confidential domain management monitor are decoupled at an ARM exception level EL2, and the virtual machine monitor and the confidential domain management monitor run in mutually isolated address spaces. The RMM is used as an independent module for dynamic loading, a management mechanism of a confidential computing domain is specially used, and the Hypervisor is only responsible for strategy scheduling, so that the defect that the Hypervisor is bloated in function in a traditional scheme is overcome. According to the method, the RMM is loaded through the security startup process during startup, the confidential virtual machine is dynamically created during running, mirror image security verification, memory encryption and other mechanisms are integrated, and finally the security domain is destroyed after the application is finished. The method has the advantages that a flexible and safe confidential computing environment conforming to the minimum privilege principle is provided for the microkernel system, and the method is particularly suitable for embedded scenes with high safety requirements such as the Internet of Things and industrial control.

The invention discloses a matrix multiplication optimization method and system for a matrix acceleration unit, and the method comprises the steps: jointly constructing a microkernel generation frame through a matrix multiplication instruction set provided by the matrix acceleration unit by adopting a thread rearrangement and address mapping strategy and a multi-stage pipeline mechanism, and generating a candidate microkernel set; feature extraction is carried out on an input matrix, a search space formed by a dynamic block and a scheduling strategy is constructed according to the features of the input matrix, an optimal microkernel is dynamically selected, and the scheduling strategy is dynamically adjusted; and constructing a performance prediction model, performing modeling and pruning on the candidate microkernel set, and preferentially selecting an optimal scheduling strategy combination in a search space to realize optimization of matrix multiplication oriented to the matrix acceleration unit. According to the method, the automation degree and adaptability of matrix multiplication optimization are remarkably improved, and the method is a universal high-performance optimization scheme which can be applied to various matrix multiplication architectures and supports a dynamic input scene.

The invention discloses an EtherCAT master station synchronous control method and system based on a microkernel operating system, and belongs to the technical field of industrial automation field bus control. According to the system, a microkernel architecture is adopted, an EtherCAT protocol stack and a universal network protocol stack are deployed as two independent user mode processes, and data interaction is carried out through an inter-process communication and shared memory mechanism provided by a microkernel. According to the method, through a bidirectional dynamic clock compensation mechanism, static compensation in an initialization stage and dynamic compensation in an operation stage of a system are combined; a dynamic task scheduling strategy based on load awareness is adopted, and the task execution sequence is dynamically adjusted according to the CPU utilization rate and the task priority monitored in real time; a hardware redundancy design of double clock sources and double communication links is introduced, and a progressive synchronous recovery strategy is adopted during switching. According to the invention, nanosecond-level synchronization precision and microsecond-level fault switching can be realized, and the method is suitable for industrial control scenes with extremely high requirements on real-time performance and reliability.

The invention discloses an industrial edge application dynamic updating method based on a microkernel, and relates to the field of industrial automation. Designing an industrial edge application based on the microkernel; and constructing a function block as a thread, and dynamically updating the industrial edge application by reconfiguring a thread entry point address. The microkernel architecture is mainly used for designing an operating system, the most basic core functions (scheduling, inter-process communication and address space management) in the operating system are realized, and all other functions such as a file system and a device driver are operated in a user layer as independent services. All services run in different address spaces in the form of threads, different services can be strictly isolated by combining access control based on Capability, and other services and kernels cannot be affected by collapse of any service. The micro-kernel architecture also adopts a modular design, and any independent module can realize thread-level loading and updating, so that dynamic updating and expansion are facilitated.

The invention discloses a cluster computing resource allocation method. The method comprises the following steps: constructing a heterogeneous computing resource pool comprising an MT CPU, an FT CPU and an MTDSP cluster; an intelligent algorithm basic calculation library is deployed, hardware mapping of a deep learning algorithm is realized through an irregular matrix multiplication optimization module, and the irregular matrix multiplication optimization module comprises a microkernel automatic generation unit which dynamically generates an assembly instruction assembly line supporting three FMAC units according to matrix dimensions; the multi-core parallel strategy unit is used for providing M-dimensional and K-dimensional parallel calculation strategies and a dynamic scheduling mechanism; dynamically selecting a row block size parameter # imgabs0 # and a column block size parameter # imgabs1 # based on the matrix shape to carry out self-adaptive adjustment on the block size; physical resources are abstracted into containers or virtual machine instances through resource virtualization, and computing resources are dynamically allocated according to matrix dimension characteristics of the intelligent training module. According to the method, automatic resource deployment strategy generation and flexible computing resource scheduling are realized, and high-performance cluster computing resource allocation and deployment services are provided for users.

Provided in the embodiments of the present application are a chip resource elastic allocation method and apparatus based on an elastic microkernel. The method comprises: configuring a data structure of a partition scheduler of each adaptive partition and a budgeted CPU running time of each adaptive partition; on the basis of the data structure of each adaptive partition, scheduling a corresponding budgeted CPU running time for a task in each adaptive partition; and when the CPU running time actually used by any adaptive partition is less than the budgeted CPU running time thereof, allocating the remaining CPU running time of the adaptive partition to other adaptive partitions that have tasks waiting for scheduling. In the technical solution of the embodiments of the present application, chip resources are dynamically and elastically allocated by means of an elastic microkernel, and on the basis of demand changes of a computing task in each adaptive partition, computing resources are dynamically allocated and adjusted, thereby ensuring bursty CPU demands, and thus meeting computing power demands of different tasks.

The invention discloses a mine multi-robot adaptive cooperative control method based on a microkernel operating system, and belongs to the technical field of mine automation and robot cooperative control. The method is cooperatively realized by running a plurality of independent service processes on a microkernel operating system: a multi-modal perception fusion process dynamically adjusts the weight of a sensor according to environmental dust and illumination, and constructs a global semantic map; in the dynamic task allocation process, multi-agent deep reinforcement learning embedded with an attention mechanism is adopted, and task allocation is modeled as a partial observable Markov decision process for solving; the hybrid path planning process constructs a hierarchical cost model based on historical traffic data, and generates a path through a three-layer planning system; the dynamic conflict resolution process utilizes STCN to predict a trajectory, and realizes prospective conflict resolution in combination with a distributed negotiation auction mechanism; and the state synchronization process adopts a lightweight practical Byzantine fault-tolerant consensus to ensure that the states of the whole system are consistent. The real-time performance, the reliability and the intelligent level of the system are remarkably improved.

The embodiment of the invention provides a chip resource elastic allocation method and device based on an elastic microkernel. The method comprises the steps that a data structure of a partition scheduler of each self-adaptive partition and CPU running time estimated by each self-adaptive partition are configured; according to the data structure of each self-adaptive partition, scheduling the corresponding budget CPU running time for the task of each self-adaptive partition; and when the CPU running time actually used by any self-adaptive partition is lower than the estimated CPU running time, the remaining CPU running time of the self-adaptive partition is allocated to other self-adaptive partitions with tasks waiting for scheduling. According to the technical scheme, the chip resources are dynamically and elastically allocated through the elastic microkernel, the computing resources are dynamically allocated and adjusted according to the demand change of the computing task of each self-adaptive partition, the sudden CPU demand is guaranteed, and the demand of different tasks for computing power is met.

The embodiment of the invention discloses a dynamic configuration and hot update method and system for an ultramicro kernel operating system. The method comprises the following steps: if system state parameters exceed a preset parameter threshold value, acquiring target system state parameters exceeding the preset parameter threshold value, and adding timestamps to obtain a system state parameter data set; calculating a moving average value and a standard deviation, and determining an abnormal system state parameter according to the target system state parameter, the moving average value and the standard deviation; and determining the configuration parameter adjustment amount of the system module corresponding to the abnormal system state parameter, and adjusting the configuration parameter of the system module based on the configuration parameter adjustment amount. According to the scheme, dynamic updating of the configuration in the ultramicro kernel operating system is realized, the system performance is optimized, the resource utilization rate is improved, and optimization and upgrading are carried out under the condition of ensuring that the service is not interrupted.

Disclosed are a capability management method and apparatus (100), and a computer device, wherein same relate to permission management of a kernel object (O) in an operating system, for example, the permission management of a kernel object (O) in a micro-kernel architecture. Specifically, in the method, two types of information are stored in a capability node (CNode) of a capability owner: information (M2) for indicating the capability to perform granting and information (M1) for indicating the capability to be granted; a correlation between the capability of a grantor and the capability of a grantee is established by means of recording the two types of information; the copying of a capability is prevented during a capability granting process; and the deletion of a capability is prevented during the process of the grantor giving up the capability, thereby ensuring a deterministic latency while realizing capability recovery and granting. The method can be applied to a smart mobile phone system, an unmanned driving system, etc.

The application discloses a power industrial control safety protection system and method based on a microkernel active defense, wherein the system takes a microkernel isolation base as a minimum trusted computing base, allocates revocable communication endpoints and controlled mapping permissions to each protection domain, and provides base support for the isolation domain boundary and permission recovery in the active defense; in the method, the system is uniformly formatted by an input module to process field data and service requests and generate a request identifier, a request distribution service distributes the same request to an odd number of online executors for parallel processing, a single decision output available externally is generated, an executor scheduling service selects a candidate executor from a candidate protection domain pool and reconstructs an online user mode service cluster according to a feedback index by adopting a periodic rotation and event triggering strategy, and if the request distribution service, the consistency arbitration service or the executor scheduling service fails, a minimum bottom-up cleaning is performed by an active defense kernel state support module and a reestablishable state is entered.

The application provides a method and device for outputting debugging information of a microkernel operating system and a storage medium. In the technical solution of the application, a Console process in a user space of a microkernel operating system can receive first debugging information of a plurality of functional modules in the user space and / or a kernel space, the Console process determines second debugging information based on the first debugging information, and the Console process sends the second debugging information to a UART through a driving module of the UART to realize output of the debugging information. Based on the debugging information, a developer can more accurately master the running status of the microkernel operating system, and thus assist the developer in improving the performance of the microkernel operating system.

The application discloses a mine multi-robot adaptive cooperative control method based on a microkernel operating system and belongs to the technical field of mine automation and robot cooperative control. The method cooperatively realizes the following processes by running multiple independent service processes on the microkernel operating system: a multi-modal perception fusion process dynamically adjusts sensor weights according to environmental dust and light, and constructs a global semantic map; a dynamic task allocation process models task allocation as a partially observable Markov decision process for solution by using a multi-agent deep reinforcement learning embedded with an attention mechanism; a hybrid path planning process constructs a hierarchical cost model based on historical traffic data, and generates a path through a three-layer planning system; a dynamic conflict resolution process uses an STCN to predict a trajectory, and realizes forward-looking conflict resolution in combination with a distributed negotiation auction mechanism; and a state synchronization process uses a lightweight practical Byzantine fault tolerance consensus to ensure that the states of the whole system are consistent. The application significantly improves the real-time performance, reliability and intelligence level of the system.

The invention discloses a method, a system and a medium for expanding and accelerating communication between microkernel processes by using memory labels, and the method comprises the following steps: distributing memories for application programs and system services, and labeling the distributed memories; realizing an isolated memory domain and an execution domain based on the label; inter-process communication is carried out in a library operating system or kernel module form by utilizing memory mark extension characteristics; and cross-service interaction is realized through the fast channel. According to the invention, the delay of inter-process communication of the microkernel is obviously reduced, and meanwhile, effective isolation and security are ensured.

The application discloses an EtherCAT master station synchronization control method and system based on a microkernel operating system, and belongs to the technical field of industrial automation fieldbus control. The system adopts a microkernel architecture, deploys an EtherCAT protocol stack and a general network protocol stack as two independent user state processes, and carries out data interaction through an inter-process communication and shared memory mechanism provided by the microkernel. The method combines static compensation in the system initialization stage and dynamic compensation in the running stage through a bidirectional dynamic clock compensation mechanism, adopts a dynamic task scheduling strategy based on load sensing, dynamically adjusts the task execution order according to the real-time monitored CPU usage and task priority, introduces a hardware redundancy design of double clock sources and double communication links, and adopts a gradual synchronization recovery strategy during switching. The application can realize nanosecond-level synchronization accuracy and microsecond-level fault switching, and is suitable for industrial control scenes with extremely high real-time and reliability requirements.

Embodiments of the present disclosure relate to a device driver method and device based on a microkernel architecture, an electronic device and a storage medium. In at least one embodiment of the present disclosure, a master-slave thread architecture mode of a driver master thread and a device slave thread is adopted, at the time of starting an operating system, only the driver master thread is started, and the device slave thread is not started, so as to reduce the consumption of system resources by the device slave thread; and the driver master thread and the device slave thread provide device driver services through an RPC mode, specifically, after the driver master thread receives a first RPC message which is a device start request, the driver master thread starts the device slave thread of the device node, and then after the device slave thread determines that a second RPC message received is a device operation request, the device node is operated correspondingly, so as to solve the problem that in the current microkernel architecture, an application cannot directly call a device driver.

The invention provides a system service calling method which is applied to a kernel under a microkernel architecture. In the system service calling method, when a kernel obtains a request of calling a certain system service for the first time by a thread, the kernel establishes connection with an execution entity of the system service and calls the execution entity to process the request, and after the execution entity finishes processing of the request, the execution entity calls the execution entity to process the request. The kernel does not clean the connection with the execution entity, but updates the state of the execution entity to a hosted state, thereby retaining the correspondence between the thread and the execution entity. Thus, when the thread continues to call the system service next time, the kernel can quickly call the execution entity in the hosting state to process the request of the thread based on the reserved corresponding relation and the connection between the kernel and the execution entity, and therefore the efficiency of calling the system service by the thread is improved.

The present invention discloses a VCPU scheduling method based on a microkernel Hypervisor. Whenever a new scheduling time slice is entered, the clock processing function is called for VCPU scheduling. The clock processing function sequentially determines whether there are potential synchronization problems with the VCPU by monitoring whether the scheduled VCPU has been enabled, whether the current thread is in the kernel state, and whether there is a thread switch. If not, normal scheduling is performed. If there are potential synchronization problems, the value and change of the preempt_count of the preemptive counter are obtained to determine whether it is a synchronization problem VCPU. If so, an additional time slice is added to enable the currently scheduled VCPU to continue running to solve the synchronization problem. The present invention uses the microkernel Hypervisor to perform VCPU scheduling based on lock detection and cooperative fairness scheduling strategies, which can reduce the performance overhead caused by lock contention in the Hypervisor, thereby improving the synchronization performance. At the same time, there is no need to modify the source code of the guest operating system, ensuring the stability and portability of the system.

The invention provides an inter-process communication method and device for a microkernel operating system, and the method comprises the steps: registering a key instruction page and a stack page in an initialization stage of a service process; constructing a process prefetching set according to the registered key instruction page and stack page; and in an inter-process communication initiating stage, loading the target page table items in the process prefetching set to the user process fast table so as to perform inter-process communication. According to the invention, the efficiency of inter-process communication of the system can be improved, and communication delay is reduced.