43 results about "System building" patented technology

The invention belongs to the field of optical detection, and particularly relates to a synchronous calibration method for a geometric pose and an optical axis error of a reflective phase deflection system, which comprises the following steps of: taking a plane mirror pose as a reference, establishing redundant geometric constraints under a plurality of poses through mirror image reflection, and jointly solving geometric external parameters of the system; and meanwhile, a reverse ray tracing model and a normal integral model are synchronously constructed in a calibration stage, surface shape data are actually measured by combining an interferometer, a system optical axis error field is explicitly stripped, and decoupling separation of a system structure error and a surface shape error is realized. According to the method, the system building process is greatly simplified, the dependence of a high-precision mechanical auxiliary device is avoided, and the overall detection precision and the low-frequency error control capability of the reflective phase deflection system are effectively improved by synchronously modeling and compensating the optical axis error of the system in the calibration stage; and a technical basis with engineering adaptability is provided for high-precision free-form surface optical detection.

The invention provides a desktop-level hardware-in-the-loop test system building method, device and equipment, and relates to the technical field of hardware-in-the-loop simulation, and the method comprises the steps: configuring a vehicle network simulation and vehicle dynamics model in an upper computer with a CAN development environment and vehicle dynamics simulation software, a real-time data channel between the two is established through a full duplex transmission protocol; a driver instruction is generated through the driving control panel, and a vehicle state signal is generated through vehicle dynamics software; the wheel speed in the vehicle state signal is converted into a physical excitation signal, and a wheel cylinder pressure signal returned by the controller is collected; the pressure signal is fed back to the vehicle dynamics model to form a closed loop, a test scene is executed, and the desktop-level hardware-in-loop test of the brake controller is completed. By using vehicle dynamics simulation software, the test confidence coefficient is improved; data exchange is carried out by utilizing an FDX protocol of a CAN development environment, and complexity and potential risks of self-development of a communication interface are avoided.

The invention belongs to the technical field of smart home and energy transmission and distribution, and particularly relates to a 4Gamp-combined system. The invention discloses an Internet of Things intelligent transmission and distribution method based on LORA wireless technology, and the method comprises the following specific steps: a data collection and uploading stage: obtaining parameter information, uploading the data to a transmission and distribution central centralized control center through an LORA module, and uploading key data to a cloud platform through a 4G module; performing data processing and analysis, comparing the collected data with a preset target value, calculating parameters to be adjusted, and performing synchronous analysis and early warning; in the control execution stage, an adjusting instruction is sent to each branch control valve and a water mixing device through an LORA module, the cold and hot water mixing proportion is adjusted so as to control the water supply temperature, and the control valves adjust the water flow of each room according to requirements; remote monitoring and feedback optimization are carried out; and intelligent learning and optimization. Accurate distribution, intelligent control and remote management of household energy are achieved, the household energy utilization efficiency is improved, energy consumption is reduced, the living comfort is improved, and meanwhile the system construction and operation cost is reduced.

The invention discloses an industrial special system building method based on large model and agent collaborative optimization, which comprises two core steps of industrial large model generation and agent collaborative optimization. The method specifically comprises the following steps: S1, generation of an industry large model: completing construction of an industry adaptation model through a data set generation module, a model fine tuning module, a model format conversion and quantification module and a model reconstruction and loading module in sequence; and S11, the data set generation module adopts an open source general large model as an initial semantic generation engine, and the method constructs a full-link system covering automatic generation of a data set, efficient fine tuning of parameters, model format conversion and quantization, model reconstruction and rapid loading, and agent construction and collaborative optimization control. And rapid injection of industry knowledge and efficient migration of model capability are realized.

The utility model relates to the technical field of light equipment, and disclose a studio light system, including roof, still include: the limiting frame is fixedly installed on the roof, and the limiting frame is rotatably connected with the guide ring, and the roof is equipped with the drive part for controlling the rotation of guide ring, the utility model discloses the integrated design is adopted, and the panel soft light and spotlight are accurately installed on the roof, and successfully build up a set of efficient convenient light building framework, and this framework breaks the cumbersome mode of traditional light system building, realizes the quick assembly of light system, and, utilize drive part to make six panel soft light have the trend of simultaneously inwards contraction or outward expansion to the rotation adjustment of guide ring, thereby convenient operator adjusts the illumination brightness and range of light according to the environment, and this kind of flexible adjustment mode can accurately satisfy the light demand under different scenes, further enhance the display effect, bring more high -quality visual experience for audience.

This invention relates to the technical fields of data quality, data management, and data governance. Specifically, it relates to a method for simultaneously conducting data governance within a newly built business information system. This method establishes a general data management standard covering data specifications, database specifications, and process specifications; builds a supervisory standard that runs through the entire process of project requirements analysis, design, development, deployment, and operation and maintenance; and integrates these two types of standards into the technical requirements of the newly built business system project. Data governance is implemented step-by-step at each stage of the project, thus avoiding data quality problems from the source of business system construction. This avoids the additional costs and schedule risks of traditional post-event governance, ensures that the system data format is uniform, secure, and compliant, and can seamlessly integrate with the enterprise's existing data governance system, solving the problems of data silos, redundancy, and inconsistency in multi-system parallel scenarios.

The application discloses a system building method, a system building device, an operating system, equipment and a medium. The system building method comprises the following steps: obtaining a configuration file of an operating system to be built, and determining at least two function units to be implemented by the operating system to be built according to the configuration file; obtaining an OS element capability corresponding to each function unit in the at least two function units, and assembling all the obtained OS element capabilities to obtain the operating system to be built. According to the embodiment of the application, the operating system is decoupled from hardware, the operating system is built in the mode of assembling OS element capabilities, the operating system can be spliced, the existing OS element capabilities can be reused, the operating system can be built on demand, and therefore, the development of operating systems of various hardware devices can be completed conveniently, quickly and at low cost, and the development difficulty and cost of the operating system are greatly reduced.

The invention discloses a multi-frequency point calibration test method and system for 0-10 Hz ultralow frequency magnetic field immunity. The method comprises the steps of system building, single frequency point reference calibration, test execution and exception handling. When the system is built, the hardware modules are connected according to a specific mode; in the calibration stage, references are established for frequency points of 2Hz, 4Hz, 6Hz and 8Hz; during testing, precise field intensity control and data recording are realized through combination of coarse adjustment and fine adjustment; and verifying the probe position when abnormity occurs. The system comprises an arbitrary function generator, a power amplifier, a radiation ring and a gauss meter, and parameters of each module are adaptive to a frequency band of 0-10Hz. The field intensity larger than or equal to 1000 A / m can be stably generated, the testing precision is improved, the 0-10 Hz frequency band standard testing blank is filled, and the device is suitable for electronic equipment testing in the fields of industrial automation, new energy automobiles and the like.

The application discloses a high-precision coordinate boring machine tool wear intelligent prediction method, and relates to the technical field of cutting tools, which comprises the following steps: step one, equipment building: determining sensor arrangement and communication scheme, and completing data acquisition system building according to the same; step two, testing: performing milling processing experiment, collecting machine tool vibration signals, measuring tool flank wear width and workpiece surface roughness, and establishing a tool wear prediction model according to the same; and step three, using: inputting the collected machine tool vibration signals in the processing process into the model, so that the current tool wear degree can be judged according to the actual vibration signals, and whether the tool needs to be replaced in time can be judged. The application identifies the vibration signal characteristics of the high-precision coordinate boring machine, can effectively improve the prediction accuracy, judges whether the tool wear degree prediction value meets the requirements, and thus prompts the engineers to replace the tool, so that the processing requirements are met.

The application discloses a kind of intelligent electric meter acquisition terminal load optimization configuration method, comprising the following steps: S1, the basic data of target area intelligent electric meter acquisition system, operating data and the cost parameters of each type acquisition terminal are obtained;Based on the basic data and operating data, the relationship model of acquisition success rate and acquisition terminal load quantity is established;Based on the cost parameters, total cost model is established;S2, with the total cost of all acquisition terminals in the target area as objective function, with the load configuration scheme of each acquisition terminal as decision variable, with the overall average acquisition success rate of the target area not less than the preset target value as constraint condition, optimization problem is constructed;S3, the optimization problem is solved using mathematical optimization solver, and the optimal load configuration scheme of each acquisition terminal is generated.The present application realizes scientific balance and global optimal configuration between system construction operation cost and data acquisition reliability.

The application relates to a distributed emergency communication guarantee system and a building method, which are used for emergency communication guarantee between two communication towers, and comprise a plurality of chassis vehicles, each of which is provided with a plurality of tracked vehicles; the front end of the chassis vehicle is provided with a cab, and the rear end of the chassis vehicle is provided with a compartment; the chassis vehicle is provided with a lifting support rod, which can form a fiber support seat together with the chassis vehicle after being lifted; each tracked vehicle is provided with a telescopic lifting rod, which can form a fiber support seat together with the tracked vehicle after being lifted when the tracked vehicle drives out of the compartment; at least one of the chassis vehicles is provided with a drone; after a plurality of the fiber support seats are arranged between two communication towers, the drone is used for pulling out the fiber on a wire coil, so that the fiber is erected between the two communication towers.

The invention discloses an in-situ lifting and reverse construction development construction method for a cultural insurance building, and relates to the technical field of cultural insurance building construction. The in-situ underground space development of the cultural insurance building is realized through the key steps of internal demolition and reinforcement, temporary pile and engineering pile construction, lifting system building, reverse B0 plate construction, underground structure sequential construction and the like. Meanwhile, corresponding technical measures are provided for retaining the difficulties of wall body roof reinforcement, latticed column perpendicularity control, outer wall jacking and falling safety, reverse B0 plate construction and the like, the problems that translation is needed for underground development of a traditional cultural insurance building, and protection and development are difficult to consider are solved, the original appearance of the cultural insurance building can be reserved to the maximum extent, the construction space is saved, and the construction cost is reduced. The method is suitable for civil insurance building updating projects in old cities.

The invention belongs to the technical field of high-speed digital circuits, and provides a signal transmission circuit board adopting strip line layout, and the signal transmission circuit board comprises a strip line layout system which comprises a data coupling module which collects resin parameters and strip line structure parameters through a sensor, calculating the real-time flowing speed of the resin by utilizing a Poiseuille flowing formula, and constructing a coupling model to output real-time side thrust after integration and cleaning; the displacement analysis module is used for superposing the curing shrinkage stress to construct a displacement pre-judgment matrix, and judging whether deviation exists or not through the lateral displacement characteristic quantity; if deviation occurs, the system building module builds a three-dimensional real-time suppression system, cooperatively applies reverse constraining force, and adjusts pressure and temperature; and the coordinated regulation and control module identifies root causes by analyzing the constraint efficiency of each unit aiming at the condition that the regulation and control do not reach the expectation, and optimizes the unit regulation and control time sequence and parameter matching to realize the real-time regulation and control of the interlayer offset if the coordination is insufficient.

The invention discloses a distribution network energy storage and charging facility joint configuration method and device and electronic equipment, and belongs to the technical field of power systems. The method comprises the following steps: setting an index meeting the coordination requirement of the energy storage capacity of the distribution network and the capacity of a charging facility, and determining a target parameter required for calculating the index; acquiring historical measurement data sorted in a time sequence; determining an influence factor of the target parameter at the current moment on the target parameter at the next moment based on the historical measurement data; calculating a target parameter prediction value at the next moment, and calculating an index prediction value of the coordination demand of the energy storage capacity of the distribution network and the capacity of the charging facility at the next moment; and adjusting the target parameter data at the next moment based on the index prediction value. According to the invention, the problem that the traditional configuration method mainly plans the energy storage and charging facilities of the distribution network independently is solved, multiple factors are considered, collaborative optimization of the energy storage system and the charging facilities is realized, the resource utilization efficiency is improved, and the system construction and operation cost is reduced.

The invention discloses a transmission method of photovoltaic intelligent operation and maintenance data, which belongs to the technical field of data transmission, and comprises the following steps of: classifying operation and maintenance data groups according to the types and layout positions of sensors to form a data group set, and verifying by using waveform similarity to ensure the accuracy of data classification. On the basis, high-risk operation and maintenance data sets are identified, and the sampling frequency and the transmission priority are dynamically adjusted for different data set sets, so that under the condition that the bandwidth is limited, transmission of key data is preferentially guaranteed, the data transmission delay and the packet loss rate are reduced, and the real-time performance and the reliability of an operation and maintenance system are improved. According to the method, the correction sampling frequency of the data group set is calculated, and the sampling frequency and the transmission priority of the non-high-risk and high-risk data groups are dynamically adjusted based on the network condition, so that intelligent distribution of data transmission resources is realized. And meanwhile, the transmission guarantee of high-risk data is improved, the bandwidth pressure is effectively relieved, and the system construction cost is reduced.

The present application relates to a kind of based on resource constraint assembly process flow planning method, it solves the current mode to production information collection, analysis requirement high, inefficient, scheduling cycle is long, response is slow, and it does not have foresight, the problem of lag assembly process.It includes the following steps: step 1: resource statistics;Step 2: process carding;1) carding each process required resource;2) carding each process required time;3) carding the absolute time sequence between process, and draw flow chart according to shortest time logic;Step 3: station content design;Step 4: system building;Step 5: digital simulation;Step 6: data collection and feedback;Step 7: bottleneck resource reserve;Step 8: iteration update;Step 9: system scheduling.The present application reduces the waiting time caused by production resource limitation, makes the existing resource play to the maximum effect, can effectively improve production efficiency, realizes assembly process flow planning based on resource constraint.

The invention belongs to the technical field of unconventional oil and gas development, relates to a shale conductivity and mechanical damage coupling correlation testing method, and aims to solve the problem that dynamic correlation of shale conductivity and mechanical damage in a complex reservoir environment cannot be accurately captured in the prior art. According to the method, synchronous monitoring of shale conductivity and mechanical damage under the combined action of hydration, temperature, confining pressure and stress loading is realized through standardized rock sample preparation, hydration treatment, multi-field parameter collaborative setting, synchronous test system building and whole-process data acquisition and analysis. According to the method, the corresponding rule of shale electrical characteristics and damage evolution under different development working conditions can be determined, a reliable experimental method support is provided for parameter optimization and reservoir stability monitoring of technologies such as underground dry distillation and hydraulic fracturing, and the method is suitable for development technology research of various shale gas reservoirs.

The application discloses an assembled steel structure multi-layer three-dimensional edible mushroom planting system building, which comprises at least two layers of building structures arranged upwards from the ground, and the building structures are steel structure frame complexes. The building structures comprise steel structure columns and cross beams arranged at least at four corners of the building structures and extending from the ground to the top. Each of the building structures is provided with a standardized planting layer frame, a ventilation and lighting system, a water supply and drainage spraying system and an environment regulation system. The application is built in a full assembled mode, the construction speed is improved by more than 70%, and the application can be put into operation quickly. All steel components, wall plates, spraying modules and ventilation modules are standardized prefabricated in a factory, and only high-strength bolts / buckle connections are used on site, without a large amount of welding and a large amount of civil construction. The building can be completed in 1-7 days, the construction period is greatly shortened, material loss is reduced, and the application can be put into operation quickly.

The application discloses a hospital business scene-oriented low-code medical information system rapid construction method, relates to the field of system building, and comprises the following steps: converting diagnosis and treatment, management and other requirements into system recognizable function description and configuration list, and mapping to a medical special component library for attribute and logic configuration; using a process engine to visually arrange a business process, setting nodes and check rules; constructing a standardized medical data model, implementing data encryption and hierarchical management; realizing data intercommunication with an existing system through an interface adaptation layer, and establishing hierarchical permissions and an audit mechanism based on a post; adopting multi-dimensional testing to ensure compliance, completing deployment and online, and establishing monitoring and iteration mechanisms.The application has the advantages that through a medical special component library, standardized configuration and an adaptation mechanism, a medical information system that is compliant, safe and can intercommunicate with an existing system is rapidly constructed, and the medical information system has flexible iteration capability, thereby helping efficient landing of hospital informatization construction.

The invention relates to the technical field of electromechanical equipment installation, in particular to an intelligent bolt hole alignment method and system based on UWB and visual microcosmic perception, and the method comprises the five steps of system building and calibration, UWB macroscopic guiding in-place, visual system starting and target recognition, multi-source data fusion and deviation calculation, and precise fine adjustment and alignment. According to the method, centimeter-level rapid coarse positioning of equipment is realized through a UWB positioning system, millimeter-level accurate sensing is performed in combination with a visual system, six-dimensional microscopic deviation is calculated by fusing multi-source data, and accurate fine adjustment is guided by using AR equipment or an execution mechanism; the system supports automatic or manual operation, achieves the centering precision of + / -0.5 mm, archives the actual pose data to a BIM database, achieves the full-process digital, high-precision and traceable bolt hole intelligent alignment, and remarkably improves the installation efficiency and safety.

The invention provides a virtual scene construction quality training and assessment system building method based on a BIM technology. The method comprises the steps of knowledge base classification; classifying quality problems; building a branch engineering BIM scene learning model; the model is lightweight; binding a corresponding quality problem component and a corresponding problem viewport in the branch engineering BIM scene misedition model; the trainee carries out training and learning by clicking the branch project; building BIM scene models of various different stages and regions in the construction process; according to the quality problem classification, separately establishing wrong version models with quality problems in different BIM construction scenes; strongly quantifying the model; setting examination questions; configuring different assessment scores and setting a score assignment rule; creating examination paper; and the student clicks on the examination module to start the examination. According to the invention, a construction quality common fault problem learning library can be provided, and project field management personnel can be helped to learn and master reasons and prevention and control measures of project construction quality problems of all sub-parts at any time.

The application provides a multi-split air conditioning system optimization control and building sub-house energy efficiency evaluation method and system, comprising: obtaining a peak regulation instruction, receiving a peak regulation target based on a virtual power plant, and determining a current multi-split air conditioning system target power value; under the current multi-split air conditioning system target power value, a current air conditioning temperature set value boundary is calculated; for each room, the human body thermal comfort condition is considered to obtain an optimized set temperature of the room; the obtained optimized room temperature set value is taken as a room reference temperature control parameter, the actual temperature setting of the current room is performed, and the temperature of each room and the corresponding room reference temperature are compared, the energy efficiency of the current room is evaluated, the thermal load difference caused by the differences in room types, the number of people and the like of different indoor units is comprehensively considered, the energy consumption is saved as much as possible under the premise of meeting the building demand response, the room temperature is optimized and set, and the energy efficiency performance evaluation of the rooms in the multi-split air conditioning system building is performed.

The present application relates to the technical field of device simulation, in particular to a kind of mother pipe circulating fluidized bed unit thermal system pressure flow modeling method, specifically as follows: mold development, in steam flow network, each mold is written algorithm, to realize the calculation of pressure, temperature, flow in flow network;System building, relevant mold is connected according to the system diagram provided by power plant, use steam medium module, the superheater system of three fluidized bed boilers and the mother pipe connected, connect two steam turbines and steam extraction system after main steam mother pipe etc.The modeling method for solving the pressure flow of the mother pipe circulating fluidized bed unit thermal system can be used for full range full process 1:1 mother pipe circulating fluidized bed unit simulation training system, can reflect the characteristics of the whole mother pipe unit, can realize the whole process simulation of mother pipe circulating fluidized bed unit, accurately simulate the dynamic and static characteristics and trend under various operating conditions of unit.

The invention discloses a logic programming system management and control method, device and equipment, and relates to the field of industrial automation, and the method comprises the steps that a frequency converter downloads a logic programming system from an upper computer; wherein the logic programming system is a system built by an upper computer based on a target function block provided by a frequency converter; the target function block is a function block without a preset function code; and based on each target function block in the logic programming system, determining a target function code required to be used from the reserved function codes, and determining a function code parameter of the target function code so as to manage and control the logic programming system by using the target function code. According to the frequency converter, the function block without the preset function code is provided to build the logic programming system, so that the use of a user is more flexible, and diversified system building requirements are better met.

The application provides a dynamic allocation method of an Al-based intelligent three-dimensional parking storage system, relates to the technical field of dynamic allocation, and is characterized in that: a system is built for a storage area, data monitoring and analysis are performed according to system building information, dynamic allocation of parking spaces is executed according to data monitoring and analysis information, dynamic adjustment and optimization of the parking spaces are performed according to dynamic allocation execution data of the parking spaces, AI vehicle recognition is performed according to dynamic parking space allocation data, intelligent charging execution is performed according to AI vehicle recognition data, data synchronization recording is performed according to intelligent charging execution data, synchronization recording data is obtained, system operation and maintenance analysis is performed according to the synchronization recording data, system operation and maintenance analysis data is obtained, system upgrade analysis is performed according to the system operation and maintenance analysis data, dynamic allocation upgrade data is obtained, and the application realizes the standardization and intelligentization of parking storage management.

The invention discloses a high-precision guiding method for jointly calculating spatial poses based on multiple cameras, and relates to the field of machine vision and robot control. The method comprises the following steps: S1, building a system and fixedly installing a camera; s2, carrying out hand-eye calibration and internal reference calibration on the single camera in the step S1; s3, manufacturing a workpiece feature point template; step S4, multi-camera joint pose solving and BA optimization are carried out; and S5, robot guiding and grabbing are conducted. According to the method, the re-projection errors of a plurality of cameras are uniformly optimized, high-precision and stable estimation of the six-degree-of-freedom pose of the large-size workpiece is achieved, the cameras do not need to have a common view field, and the guide precision can be within 0.2 mm.

The utility model discloses a distribution line isolation compensation device, which is connected between a system bus and a protection line to realize isolation and compensation of the protection line when a single-phase earth fault occurs, and comprises a primary winding, a load winding and a compensation winding which are mutually coupled, the primary winding is respectively connected with each phase of a system bus; the load winding is respectively connected with each phase of the protection circuit and supplies power to power distribution equipment of the protection circuit; the compensation winding and the load winding are opposite in polarity, and neutral points are grounded. According to the utility model, isolation of a protection circuit and compensation of the protection circuit when a single-phase earth fault occurs can be realized, rapid arc extinguishing is realized, efficiency is improved, occurrence of electric shock danger of personnel is avoided, system construction and maintenance cost is greatly reduced, and the system is suitable for popularization and application. Various faults caused by mutual cooperation among a plurality of devices are avoided, and reliable guarantee is provided for stable operation of the system.

The invention discloses a design method of a virtual experiment platform for designing a hydraulic system based on AI guidance. The design method comprises the following steps: (1) designing an overall framework of the virtual experiment platform; (2) construction of an AI learning guiding database; (3) designing an experiment preparation module; (4) designing a load analysis module; (5) designing a hydraulic cylinder parameter calculation module; (6) designing a scheme design module; (7) designing a hydraulic element selection module; and (8) designing a simulation operation and system building module. According to the method, each step in the hydraulic system design steps can be completed according to the steps, and finally, the learning process and data of students are recorded by AI in combination with the whole experiment process, and a teaching quality report is generated to give experiment results; aI guiding learning automatically judges the correctness in the design calculation process, the comprehensiveness is high, the depth participation degree is high, and the system design process is complete.

The application belongs to the technical field of photo-thermal power generation, and provides a tower type photo-thermal pipeline support system arrangement structure and a photo-thermal system. The tower type photo-thermal pipeline support system arrangement structure comprises a first molten salt pump support arranged in a horizontal direction, used for supporting a first hot molten salt pump and a molten salt pipeline located between a first cold molten salt tank and a first hot molten salt tank; a first cold molten salt pump support is vertically arranged at one end of the first hot molten salt pump support, used for supporting a first cold molten salt pump and a molten salt pipeline located between the first cold molten salt tank and the first hot molten salt tank; a heat exchange support is vertically arranged at the other end of the first hot molten salt pump support; the heat exchange support is used for supporting a molten salt pipeline located between the first hot molten salt tank and a steam generation system building; and a heat collection support is arranged at the end of the first cold molten salt pump support and arranged in a vertical direction with the first hot molten salt pump support, used for supporting a molten salt pipeline located between the first cold molten salt tank and an absorption tower.

The invention discloses a special working medium turbine power generation experiment platform based on hydraulic braking and a testing method, and belongs to the technical field of turbine mechanical performance testing. The experiment table comprises a compressor, a special working medium gas storage tank, a pressure flow adjusting system, a turbine experiment section, a hydraulic power measuring device and an experiment table body. The pressure flow adjusting system accurately controls parameters of a special working medium entering a turbine through an electric adjusting valve and a flow meter; the turbine experiment section converts the energy of the high-pressure special working medium into mechanical energy; the hydraulic dynamometer measures the output power of the turbine through a brake disc, a hydraulic brake caliper and a dynamometer, and measures the rotating speed of the turbine through a speed meter. The test method comprises the steps of system establishment and calibration, initialization, gas source starting, working condition adjustment and test, and multi-working condition data acquisition and data analysis. The method has the advantages of being accurate in control, reliable in measurement, low in investment cost and the like, the turbine performance curve can be efficiently obtained, and experimental support is provided for turbine design and optimization.