Abstract: Disclosed is a discrete event simulation method using Matlap object-oriented programming (OOP). The method of simulating a discrete event comprising a plurality of models and a root coordinator, comprises: the root coordinator's managing time schedules of the models; the root coordinator's calling a model function based on the time schedules; and the models' transmitting external input events to each other when the model function is called, based on a coupling structure of the models, wherein when the plurality of models transmit the external input events to each other, the external input events are transmitted as an input parameter of the model function.

Abstract: ANN Loadflow Computation Method (LCM) is invented involving input vector composed of net nodal injected real power (P), reactive power (Q), and diagonal elements of conductance and susceptance matrices multiplied by squared initial guess node voltage magnitude (V) or sum of its squared real and imaginary components. Training, and testing and validating input data sets/vectors are generated by applying uniform and non-uniform scaling factors applied to base case loads P and Q at PQ-nodes, and resistance and reactance of network branches. These scale factors are increased until Loadflow Solution by a conventional LCM diverges due to V or angle (?) instability. V and ? values in the solution just before divergence are respective stability limits, and corresponding values in Loadflow Solution provide direct measure of respective stability margins. Suresh's diakoptics based feature selection technique is presented for calculating one node variable with one neuron in each of ANNs output layers.

Abstract: The present invention provides apparatus and methods to perform thermal management in a computing environment. In one embodiment, thermal attributes are associated with operations and/or processing components, and the operations are scheduled for processing by the components so that a thermal threshold is not exceeded. In another embodiment, hot and cool queues are provided for selected operations, and the processing components can select operations from the appropriate queue so that the thermal threshold is not exceeded.

Abstract: Systems and methods of emulating power system operations. The Emulation system may include a software model of an engine driven electrical power generator, Emulation code to enable various testing of one or more power system components, and using real-world values, where applicable, to enhance the Emulation and test operation of the power system. An example method may include receiving a desired operating configuration of a proposed power system. The method may also include simulating operating data of at least one component of the power system. The method may also include emulating operations of the proposed power system using at least some actual operating data and the simulated operating data. The method may also include outputting emulated operational data for the proposed power system into an actual control and monitoring system to emulate operations of the proposed power system.

Abstract: Among other things, one or more techniques and/or systems are provided for maintaining an electrical network model describing an electrical network. A fault detection, fault isolation, and load restoration (FDIR) component, a voltage/var control (VVC) component, and/or other components may be provided with access to the electrical network model so that the components may have access to relatively up-to-date and/or accurate information describing the electrical network when executing functionality for the electrical network. For example, the FDIR component and the VVC component may be synchronized based upon the electrical network model so that the FDIR component may have notice of network changes by the VCC component, and/or the VCC component have may have notice of network changes by the FDIR component.

Abstract: A power grid model system, method and computer program product which includes a switching state processor, a topological processor, an equipment update processor, and a historic power grid model for a power grid. The historic power grid model has an equipment layer and a topology layer. Responsive to a switch operated in a power grid, the switching state processor is notified of the operated switch, notifies the topological processor of the operated switch and notifies the power grid model for updating of the historic power grid model; and the topological processor determines the extent of the update of the power grid model, parses through details of the equipment layer and updates the topology layer in the power grid model.

Abstract: A computer aided design application modifies a CAD drawing having one or more electrical components by optimizing a plurality of circuits and associated panels, and assigning circuit and panel identifiers to each component for producing an engineering drawing. Further such identified components can be placed in home run groups, implementing shortest path calculations for various wire types and using neutral wires sharing options for producing an engineering drawing illustrating the home run grouping and identifiers, panel schedules and complete bills of materials.

Abstract: Systems and methods for model-based real-time solar power management. In an embodiment, real-time data is received from sensor(s) of an electrical system comprising a photo-voltaic power generator. Predicted data is generated based on a virtual model of the electrical system that replicates operation of the sensor(s). The virtual model is continuously and automatically synchronized with the electrical system based on a difference between the real-time data and the predicted data. Solar irradiance forecast data may also be received and used in conjunction with the virtual model to forecast a power output of the photo-voltaic power generator.

Abstract: A multi-dimensional energy control system is provided with an energy management software application that organizes the consumption of energy by a device as an n-dimensional energy space, where n is an integer greater than 2, and each axis in the energy space represents an energy consumption characteristic. The energy management application generates instructions for a device in response to calculating a compromise operating point in the energy space. A user interface (UI) connected to the energy management application has a display to receive a graphical representation of the energy space and compromise operating point, and an input to receive user commands for moving the represented compromise operating point in the represented energy space. The energy management application calculates the compromise operating point in the energy space to match the displayed compromise operating point.

Abstract: The present invention relates to a real time dynamic physics simulation device of flexible DC transmission system. The device includes simulated converter transformer, simulated AC field, simulated DC field, simulated converter reactor, simulated converter, and measurement and control cabinet chassis; the simulated AC field includes the vacuum switch I, the contactor I, resistors and the vacuum switch II connected orderly; the simulated DC field includes successively connected the vacuum switch contactor III and II; the simulated AC field is connected with said measurement and control cabinet chassis; Said converter transformer is set between said resistors and said vacuum switch II; Said simulated converter reactors and said simulated converter connected are set between the vacuum switch II and the vacuum switch III.

Abstract: Aspects of state estimation for cooperative electrical grids are disclosed. State estimation of a local electrical grid can be based on a local grid model and local electrical grid information. The local state estimation can reflect interactions and interconnections with other electrical grids by determining state estimation solution information based on the local grid model, local electrical grid information, and remote state estimator solution information associated with the other electrical grid. As such, a local state estimator can be configured to receive and employ remote state estimator solution information. This can be in addition to the more conventional technique or receiving a remote grid model and remote electrical grid information to estimate the conditions of the remote electrical grid. Further, state estimation solution information can be incremental to further reduce the amount of information to be transferred and the time needed to accomplish transmission of the information.

Abstract: The present invention provides a circuit simulation method of executing a high-precision circuit simulation. A voltage fluctuation analysis step at a gate level is executed (step S2). The voltage fluctuation analysis step at the gate level is executed on an entire chip TP. Next, a step of obtaining waveforms of power supply voltage and ground voltage (Vss) according to the voltage fluctuation analysis step is executed (step S4). Subsequently, a signal analysis step at a transistor level is performed (step S6). The signal analysis step at the transistor level is performed in an area narrower than the entire chip TP, for example, on one or more functional modules. After that, a step of obtaining a signal analysis result according to the signal analysis step is executed (step S8).

Abstract: A method of generating an ion implantation distribution by a computer is disclosed. The method includes calculating ion implantation distribution regions in a case of generating the ion implantation distribution with a large tilt angle and generating an analytical model of the ion implantation distribution in correspondence with each of the ion implantation distribution regions by using a Gauss distribution model, in which the ion implantation distribution regions have different influence on a channel region depending on a gate structure formed on the ion distribution regions.

Abstract: A power system data model conversion method, a power system data model conversion system and a power system data model conversion program which are to perform a fast power system analysis and used for a power system analysis capable of reducing inconsistency with another information system, wherein all instances used for the power system analysis are read out from a CIM database server which is commonly used on a power system information system, and a connected relation between instances is constructed while performing recursive retrieval. And, conversion processing of the data model is performed to integrate information necessary for the power system analysis and dispersed to extend over the plural classes of a CIM data model into one class.

Abstract: A method and apparatus for electrical power system stability optimization. An electrical power system comprising source elements and load elements is simulated to generate impedance data, wherein the impedance data identifies an impedance of the electrical power system. A stability profile of the electrical power system is characterized as a function of the impedance data, wherein the stability profile identifies the source elements and load elements to control power generation by the electrical power system to optimize stability of the electrical power system.

Abstract: In one embodiment, an IR drop analysis methodology may include characterizing standard cells without including power parasitic impedances, extracting the power parasitic impedances for the standard cells, and characterizing the standard cells with the power parasitic impedances. A set of timing parameters (such as minimum delays and maximum delays through the cells) may be generated from each characterization. The methodology may include comparing the timing parameters from each characterization, and identifying cells for which additional design effort should be expended to improve the power supply grid (e.g. to reduce the power parasitic impedances). For example, a margin may be budgeted for speed loss (delay increase) due to IR drop. If the difference in the timing parameters exceeds the margin, additional design effort may be warranted.

Abstract: One embodiment of the present invention provides a system for performing a real-time, in-the-field switching-sequence simulation for a power system that includes a plurality of switching devices. During operation, the system receives a request, from a user at a handheld device, to perform an operation on a switching device in the power system. In response to the request, the system identifies the switching device from the plurality of switching devices, obtains instant status information associated with the plurality of switching devices, and runs a simulation, at the hand-held device, based on the instant status information and the identified switch device. The system then determines whether the operation is allowed based on an outcome of the simulation.

Abstract: Disclosed are systems and methods for calculating load models and associated tunable parameters that may be used to describe the behavior of loads connected to an electric power distribution system. The load models may be utilized to predict variations in demand caused by changes in the supply voltage, and may be utilized in determining an optimized control strategy based on load dynamics. Any action which causes a disruption to the electric power distribution system may provide information regarding the composition or dynamics of connected loads. Such actions may be referred to as modeling events. Modeling events may occur with some frequency in electric power distribution systems, and accordingly, a number of data sets may be acquired under a variety of conditions and at a variety of times. Load models may include static load models, dynamic load models, or a combination of static and dynamic load models.

Abstract: A performance evaluation device includes: a control timing model unit for outputting a timing for inputting a control signal input/output between plural function blocks contained in a simulation model corresponding to a hardware; a control signal transfer period calculation unit for calculating a transfer period of the control signal between the plural function blocks in accordance with the timing for inputting the control signal; a data timing model unit for outputting a timing for inputting a data signal corresponding to the control signal, which is input/output between the plural function blocks; and a data signal transfer period calculation unit for calculating a transfer period of the data signal between the plural function blocks in accordance with the timing for inputting the data signal.

Abstract: A system for making real-time predictions about an arc flash event on an electrical system is disclosed. The system includes a data acquisition component, an analytics server and a client terminal. The data acquisition component is communicatively connected to a sensor configured to acquire real-time data output from the electrical system. The analytics server is communicatively connected to the data acquisition component and is comprised of a virtual system modeling engine, an analytics engine and an arc flash simulation engine. The arc flash simulation engine is configured to utilize the virtual system model to forecast an aspect of the arc flash event.

Abstract: The present invention provides novel techniques for controlling energy systems. In particular, parametric hybrid models may be used to parameterize inputs and outputs of groups of equipment of energy systems. Each parametric hybrid model may include an empirical model, a parameter model, and a dynamic model. Critical parameters for groups of equipment modeled by the parametric hybrid models, which are correlated with, but not the same as, input and output variables of the groups of equipment may be monitored during operation of the energy system. The critical parameters may be used to generate optimal trajectories for the energy system, which may be used to control the energy system.

Abstract: An analysis method for turbine-generator torsional vibrations affected by power transmission system, which is processed by a computer system with a simulation software, is proposed. This analysis method comprises: building structures of a first system model and a second system model to respectively simulate a first system and a second system; building detailed models of the first and second system model; and analyzing the detailed models of the first and second system model in frequency- and time-domain.

Abstract: An autonomous floor cleaning robot includes a transport drive and control system arranged for autonomous movement of the robot over a floor for performing cleaning operations. The robot chassis carries a first cleaning zone comprising cleaning elements arranged to suction loose particulates up from the cleaning surface and a second cleaning zone comprising cleaning elements arraigned to apply a cleaning fluid onto the surface and to thereafter collect the cleaning fluid up from the surface after it has been used to clean the surface. The robot chassis carries a supply of cleaning fluid and a waste container for storing waste materials collected up from the cleaning surface.

Abstract: Techniques for optimizing a distribution circuit (e.g., electric power grid) are described. Primary wiring of a distribution circuit may comprise a plurality of unique primary paths, from a source to an end (a transformer). Each primary path may include a plurality of primary segments, and each primary segment may be in one or more primary paths. A maximum voltage drop on any primary segment may be selected as a smallest of maximum allowed voltage drops across that segment in each of the primary paths. Because the voltage drop across each primary path must be less than a prescribed maximum, the sum of the voltage drops across each primary segment in that primary path is less than the prescribed maximum. The prescribed maximum may be adhered to if each primary segment is constructed of a conductor gauge chosen not to exceed the maximum voltage drop for that segment.

Abstract: A method is provided for determining the internal temperature of an electrochemical energy storage device, particularly for a motor vehicle. The internal temperature of a cell winding of the energy storage device is determined by calculation in a control device of the energy storage device by way of a thermal model for the energy storage device which is saved in the control device.

Abstract: A signal generator produces a victim signal having crosstalk emulation by filtering and combining a victim signal waveform record file and an aggressor signal waveform record file generated using parameters selected by a user. A signal channel or a cascaded signal channel is characterized using one or more S-parameter arrays. The S-parameter array or arrays represent a mixed-mode multiple-port device under test. Coefficients of a NEXT filter, a FEXT filter and a forward transmission filter are derived from selected S-parameters of the S-parameter array. The aggressor signal is filtered individually by the NEXT and FEXT filters. The victim signal is summed with the filtered aggressor signal from the NEXT filter with the resulting summed signal being filtered by the forward transmission filter. The filtered signal from the forward transmission filter is summed with the filtered aggressor signal from the FEXT filter to generate a victim signal having crosstalk emulation.

Abstract: A modeling system and modeling method based on a logical relation, including an operation task integrating module, a task interpreter, a graph layout correcting module, a graph wiring correcting module and a database model increment correcting module, wherein the database model increment correcting module includes a graph increment calculating unit and a model increment calculating unit. The system, through description of the logical relation and based on support of the automatic wiring technology, realizes the graph-model integrated generation of a new grid model of the power system which is based on the description of the logical relation; the grid model is completely defined and modified on “one net”, which is different from the original way that the power system model is established on countless net graphs, thereby helping the grid operation manager to accurately and rapidly establish and modify the grid model of the full system.

Abstract: A method for verifying power management of an integrated circuit design includes estimating a current load requirement of clocked modules in the circuit design based on the clock frequency and a predefined current load model. The voltage supplied to the circuit design is monitored. A first voltage regulator provides additional current drive to the circuit design when the supplied voltage drops below a threshold value of a full throttle run mode of the circuit design. A second voltage regulator is enabled to boost a response time of the first voltage regulator when the voltage drops below the threshold value.

Abstract: A System for predicting energy need of a plurality of electric-energy vehicles across a determined management area. A processor in the system aggregates, from each electric-energy vehicle within the management area, positional information and energy-need information of each electric vehicle. The processor is adapted to process the positional information and the energy-need information by way of a cognitive method, to determine predictions of the movement of the vehicle and endurance of the battery. The processor is further adapted to combine this determined information to generate a predicted energy distribution model over said management area, indicative of future energy needs for said electric-energy vehicles.

Abstract: A method for solving a two-stage non-linear stochastic formulation for the economic dispatch problem under renewable-generation uncertainty. Certain generation decisions are made only in the first stage and fixed for the subsequent (second) stage, where the actual renewable generation is realized. The uncertainty in renewable output is captured by a finite number of scenarios. Any resulting supply-demand mis-match must then be alleviated using high marginal-cost power sources that can be tapped in short time frames. The solution implements two outer approximation algorithms to solve this nonconvex optimization problem to optimality. Under certain conditions the sequence of optimal solutions obtained under both alternatives has a limit point that is a globally-optimal solution to the original two-stage nonconvex program. A further decomposition approach derived from the Alternating Direction Method of Multipliers algorithm is implemented.

Abstract: Certain embodiments herein are directed to systems and methods to predict failures in power systems equipment. In one embodiment, one or more life-span models associated with power systems equipment may be received. Examples of such life-span models may include a left-censoring model, a right-censoring model, and an interval-censoring model. An accuracy of the life-span models may be determined based at least in part on statistical analysis, such as a Weibull distribution analysis. A stability of the life-span models may also be determined, in certain embodiments herein.

Abstract: A method for performing battery cell control with aid of virtual battery mechanism is provided. The method is applied to a power supply device. The method includes the steps of: generating a virtual total output voltage level according to a total output voltage level of a set of battery cells connected in series within the power supply device, where the virtual total output voltage level simulates an output voltage level of connecting the set of battery cells and at least one virtual battery cell in series; and utilizing a battery cell control chip within the power supply device to control operations of the set of battery cells according to the virtual total output voltage level. An associated apparatus is further provided.

Abstract: A static heat transfer model is derived from a system of dynamic equations by integrating the dynamic equations over different time periods. That static heat transfer model links periodic (e.g., monthly) energy usage with cooling and heating degree hours, humidifying and dehumidifying hours. Its coefficients of measuring correlations correspond to the thermal parameters of buildings. Temporal data from a building may be used to estimate the overall heat transfer parameters. A clustering scheme may be developed to decompose all the buildings into different clusters based on one or more similarity criteria. The overall heat transfer parameters are separated into values for the wall, roof and window using multiple buildings' data in the same cluster or group.

Abstract: In at least some embodiments, a computer system includes a processor and a storage device coupled to the processor. The storage device stores a program that, when executed, causes the processor to simulate restoration of a power grid system and to generate a restoration plan for the power grid system based on the simulation.

Abstract: An energy facility control system transforms the manner in which energy facilities create, modify, share, and store information during all phases of their lifecycles, from licensing through construction and decommissioning. The energy facility control system provides energy operators and their suppliers with collaborative toolsets to help improve accuracy, reliability and efficiency during every stage of an energy facility's lifecycle.

Abstract: A system, a method and a computer program product for determining an amount of an electric power to be generated in an electric power system and determining a total cost for generating the amount of electric power while satisfying at least one contingency constraint and one or more customer request. The system creates an optimization problem for calculating amount of the electric power to be generated and a total cost for generating the calculated amount of the electric power while meeting the at least one contingency constraint. The system runs the optimization problem in real-time. The system outputs, from the optimization problem, an output specifying the calculated amount of the electric power and the total cost to generate the calculated amount of the electric power.

Abstract: A system for making real-time predictions about an arc flash event on an electrical system comprises a data acquisition component communicatively connected to a sensor configured to acquire real-time data output from the electrical system; an analytics server communicatively connected to the data acquisition component and comprising a virtual system modeling engine configured to generate predicted data output for the electrical system using a virtual system model of the electrical system, an analytics engine configured to monitor the real-time data output and the predicted data output of the electrical system, and an arc flash simulation engine configured to use the virtual system model updated based in the real-time data to forecast an aspect of the arc flash event.

Abstract: One embodiment of the present invention provides a system for performing a real-time, in-the-field switching-sequence simulation for a power system that includes a plurality of switching devices. During operation, the system receives, at a hand-held device, topology information associated with the power system, a set of user-definable rules, and a request to perform an operation on a switching device in the power system. In response to the request, the system identifies the switching device from the plurality of switching devices, obtains instant status information associated with the plurality of switching devices, and runs a simulation based on the topology information, the user-definable rules, the status information, and the identified switch device. The system determines whether the operation is allowed based on an outcome of the simulation.

Abstract: A voltage regulation optimization (VRO) system receives inputs from a DCS or other distribution network control/monitoring system. The VRO then calculates optimized control commands for various network devices including the controllable taps of voltage regulating transformers.

Abstract: An approach is provided in which a power design verification system retrieves a power intent data corresponding to a power design, which identifies the power design's power modes and power mode transition conditions. The power design verification system selects one of the power mode transition conditions, which identifies input signals that invoke a transition from a first power mode to a second power mode. In turn, the power design verification system generates simulation stimuli based upon the identified input signals and simulates the power design utilizing the generated simulation stimuli accordingly.

Abstract: A system for filtering and interpreting real-time sensory data from an electrical system is disclosed. The system includes a data acquisition component, a power analytics server and a client terminal. The data acquisition component acquires real-time data output from the electrical system. The power analytics server is comprised of a virtual system modeling engine, an analytics engine, and a decision engine. The virtual system modeling engine generates predicted data output for the electrical system. The analytics engine monitors real-time data output and predicted data output of the electrical system. The decision engine compares the real-time data output against the predicted data output to filter out and interpret indicia of electrical system health and performance. The client terminal is communicatively connected to the power analytics server and configured to display the filtered and interpreted indicia.

Abstract: A processor-implemented method for improving efficiency of a static core turn-off in a multi-core processor with variation, the method comprising: conducting via a simulation a turn-off analysis of the multi-core processor at the multi-core processor's design stage, wherein the turn-off analysis of the multi-core processor at the multi-core processor's design stage includes a first output corresponding to a first multi-core processor core to turn off; conducting a turn-off analysis of the multi-core processor at the multi-core processor's testing stage, wherein the turn-off analysis of the multi-core processor at the multi-core processor's testing stage includes a second output corresponding to a second multi-core processor core to turn off; comparing the first output and the second output to determine if the first output is referring to the same core to turn off as the second output; outputting a third output corresponding to the first multi-core processor core if the first output and the second output are b

Abstract: An arrangement provides simulation of important battery factors such as state of charge or state of health, and the estimates are provided to the human user in ways that permit the human user to make better use of the battery, for example in an electric car. The arrangement uses modeling elements that communicate with each other by means of an analog bus. Some lines on the analog bus are voltages that are intended to be inputs to the simulation or actual measured values from a physical system. Other lines, importantly, are “voltages” that are intended to communicate characteristics of interest such as open-circuit voltage of a cell. Still other lines may be “voltages” that merely pass messages between modeling elements, the voltages not necessarily representing any real-life measurable such as the afore-mentioned temperature value.

Abstract: Analyzing one or more physical infrastructure elements of a data center by generating a plurality of outputs from a stochastic process for a set of inputs to the stochastic process. The inputs comprise one or more inputs of certainty and one or more inputs of uncertainty. A statistical output analysis of the outputs is utilized to generate one or more threshold reaching projections for each of the physical infrastructure elements of the data center.

Abstract: A method for modeling a nuclear reactor core that follows the history of each fuel pin and employs fuel pin flux form factors to explicitly track each fuel pin's fluence and burnup along its axial length and uses this information to obtain fundamental data for each fuel rod, i.e. fuel rod cross-sections, for each fuel pin segment. The data obtained for the fuel pins segments are employed to adjust the fuel pin flux form factors to match the real fuel pins' history so that the fuel rod power distribution can be precisely calculated based on the fuel rod cross-sections and the flux form factors.

Abstract: A system and method for providing real-time modeling of an electrical power system for demand response. In an embodiment, real-time data is acquired from an electrical power system. Predicted data is generated for the electrical power system utilizing a virtual system model of the electrical power system. If a difference between the real-time data and predicted data exceeds a threshold, a calibration and synchronization operation is initiated to update the virtual system model to provide predicted data that is consistent with the real-time data. In addition, patterns observed from the real-time data and predicted data may be processed, and an aspect of the electrical power system can be forecasted. The forecasted aspect may then be provided to a demand response market system.

Abstract: In a renewable energy-based electricity grid infrastructure, distributed data analytics enable modeling and delivery of an appropriate, time-sensitive, dynamic demand response from multiple renewable energy resource components to an intelligent power distribution network. Distributed data analytics also enable the electricity grid infrastructure to virtually, optimally and adaptively make decisions about power production, distribution, and consumption so that a demand response is a dynamic reaction across the electricity grid infrastructure in a distributed energy generation from multiple renewable energy resources responsive to various types of grid demand situations, such as customer demand, direct current-specific demand, and security issues, and so that power production is substantially balanced with power consumption.

Abstract: A system and method migrating virtualized environments is disclosed. According to an aspect of the disclosure, a home energy management system and method includes a database configured to store site report data received from a plurality of residential sites using a wireless home energy network at each site. Each residential site includes a thermostat accessible to the wireless home energy network. A processor is operably coupled to the database and configured to access the site report data and detect a current temperature set-point of the thermostat at a first residential site; detect a first seasonal profile of the thermostat; detect a current operating mode of a HVAC system operably coupled to the thermostat; and determine a thermostat schedule of the thermostat using the first seasonal profile and the current operating mode of the HVAC system.

Abstract: A transaction level (TL) system power estimation method and system are provided. The method includes inserting at least a characteristic extractor into an electronic device of a target system. The characteristic extractor extracts at least a power characteristic of the electronic device when a TL simulation is proceeding. The power characteristic provided from the characteristic extractor is converted to at least a power consumption value by using a power model. The power consumption value is recorded into a power database, for analyzing power consumption of the whole target system. In some embodiments, the TL system power estimation method and system can be applied in the target system with dynamic power management. The TL system power estimation method and system also can be used with a high-level synthesizer to develop the power-aware electronic device in a short time.

Abstract: A method for early detection and anticipatory control of consumer-end load shedding in a single-phase or polyphase electrical grid supplied with single phase or polyphase by at least one generator driven by at least one rotating machine includes measuring a current and a voltage between the at least one generator and the electrical grid and/or a current and a voltage in the electrical grid, deriving at least one signal from the measured current and voltage and using the at least one derived signal to act on the at least one rotating machine.