Abstract: A user may simulate wearing real-wearable items, such as virtual garments and accessories. A virtual-outfitting interface may be provided for presentation to the user. An item-search/selection portion within the virtual-outfitting interface may be provided. The item-search/selection portion may depict one or more virtual-wearable items corresponding to one or more real-wearable items. The user may be allowed to select at least one virtual-wearable item from the item-search/selection portion. A main display portion within the virtual-outfitting interface may be provided. The main display portion may include a composite video feed that incorporates a video feed of the user and the selected at least one virtual-wearable item such that the user appears to be wearing the selected at least one virtual-wearable item in the main display portion.

Abstract: Improved 8-node hexahedral elements configured for reducing shear locking in finite element method are disclosed. According to one aspect, aspect-ratio based scale factors are introduced to modify partial derivatives of the isoparametric shape function of the hexahedral element with respect to isoparametric dimensions, respectively. The modified derivatives are used for calculating the Jacobian matrix thereby the rate-of-strain. The scale factor is configured such that no changes for a perfect cubic solid element (i.e., element having aspect ratio of 1 (one) in all three spatial dimensions), while significant changes for element having poor aspect ratio. In other words, elements with poor aspect ratio are mapped to a perfect cubic element using the aspect-ratio based scale factors. According to anther aspect, off-diagonal components in the local Jacobian matrix are directly modified by cancelling terms related to spurious shear deformation modes.

Abstract: A system and methods are disclosed herein for modeling a mechanical system having body elements movable in at least two dimensions in a graphical modeling environment. The system and methods described herein allow constraints on body elements movable in at least two dimensions in the mechanical system to be generalized and represented by a single block in the graphical modeling environment. The system and methods described herein simplify the modeling of a mechanical system by allowing a user to construct a definition of generalized constraints through a connectivity table. Thus, it is possible to model a mechanical system in a graphical modeling environment with less than all the body elements represented by blocks in a graphical model.

Abstract: A method for computer-aided generation determining of a method plan for the manufacture of sheet-metal forming parts by way of forming processes, comprises the following steps: determining a set of geometry features (11, 12, 13, 14, 15) of a part (10) in a geometry model of the part (10), wherein each of the geometry features (11, 12, 13, 14, 15) is described by a feature type and by way of geometric parameters for describing the geometric shape of the geometry features (11, 12, 13, 14, 15); determining an associated method standard for each of the geometry features (11, 12, 13, 14, 15), wherein a method standard describes one variant for manufacturing the respective geometry feature (11, 12, 13, 14, 15), the selection of the method standards which may be associated with a certain geometry features (11, 12, 13, 14, 15), is dependent on the feature type of the geometry feature (11, 12, 13, 14, 15), and wherein a method standard comprises at least one module, and a module represents a processing unit and des

Abstract: A simulation environment for running a process simulation used to validate an industrial control program. The simulation environment exposes the I/O module configurations defined in the control program and retrieves module configuration information therefrom. This I/O module configuration information is combined with generic, module-specific I/O module profiles to create a pool of available controller I/O points, which can be selectively associated with I/O points in the simulation to create an I/O point mapping. During control program validation, simulated I/O data is exchanged between the process simulation and the I/O module instances in the controller in accordance with the I/O point mapping.

Abstract: The present disclosure is directed to a computer-implemented method for modeling a mounting assembly having a mounting strap configured to couple a component to a bracket. The method includes modeling a loosened configuration of the mounting strap, wherein the loosened configuration provides a first substantially continuous curvature of portions of the mounting strap engaged with the bracket and the component. The method also includes applying simulated stresses to the mounting strap in the loosened configuration and outputting failure mode information of the mounting strap based on the simulated stresses on the mounting strap.

Abstract: A method and a system for analyzing turbomachinery is provided. In one embodiment, a system for analyzing turbomachinery is provided. The system includes an intelligent turbomachinery tracking filter (ITTF) system configured to determine one or more performance shifts for one or more components of the turbomachinery based on a plurality of turbomachinery parameters. The system further includes a root cause analyzer configured to determine a root cause of the turbomachinery performance based on the one or more performance shifts. The one or more performance shifts include trended data.

Abstract: Models for predicting ice formation and/or accumulation on wind turbine blades and methods of their use in optimizing performance of wind turbines in the presence of adverse local weather conditions are disclosed. In certain embodiments, the predictive models include historical data of local meteorological conditions including, inter alia, wind speed, temperature, and relative humidity conditions and are useful, inter alia, for preemptively managing performance of wind turbines operation/shutdown cycles in response to a future predicted blade icing event based on a model of the present invention.

Abstract: An engine simulator is utilized for training purposes. The simulator comprises a fully functioning control system and pressure modules, pumps and variable drive motors to simulate a engine faults. A programmable logic controller and other related components simulate engine activities and operational sequences that interface with controls system. A trainer is able to “bug” the system physically, electronically or via programming, thus allowing applied on the job training during the course of instruction without any service interruption to real equipment.

Abstract: A method, system, and computer readable medium for identifying wall features in an object model represented in a CAD system. A method includes loading an object model in a CAD system and receiving a selection of a first face of the object model by the CAD system. The method includes finding candidate wall faces by the CAD system and storing the candidate wall faces in a candidate list, and designating at least one candidate wall face in the candidate list as a counterpart face to the first face. The method includes storing the first face and the counterpart faces as a wall of the object model. Some methods include removing at least one second face from the candidate list based on an exclusion rule.

Abstract: According to one embodiment of the invention, a computerized method for simulating human movement includes storing a plurality of sets of data, in which each set of data is indicative of a measured movement of a first human, receiving a start point and an end point for a desired movement of a second human, and comparing the desired movement to the stored sets of data. The method further includes selecting, based on the comparison, a stored set of data that is representative of the desired movement and simulating the desired movement based on the start point, the end point, and the relative change in position of a first joint associated with the selected set of data from an empirical start point to an empirical end point.

Abstract: A system, method, and computer program product are provided for compiling code adapted to execute utilizing a first processor, for executing the code utilizing a second processor. In operation, code adapted to execute utilizing a first processor is identified. Additionally, the code is compiled for executing the code utilizing a second processor that is different from the first processor and includes a central processing unit. Further, the code is executed utilizing the second processor.

Abstract: Systems and methods for the automated positioning of pads and orienting of slot templates for the pads. The systems and methods also include automated adjustment of well path plans from a pad to selected well targets.

Abstract: A method for operating a service oriented architecture (SOA) based wire harness system, a corresponding system, and a machine readable medium. The method includes storing wire harness data in a wire harness data model in a wire harness data processing system, interactively communicating the wire harness data with an electronic computer aided design (ECAD) system and a mechanical computer aided design (MCAD) system through the SOA interface, and storing the wire harness data in the wire harness data model.

Abstract: A method for determining when a ceramic component on a platform should be replaced. The method includes determining parameters for the ceramic component, the parameters include empirically determined a critical stress intensity factor, and a geometry factor for the ceramic component. The method also includes determining a relationship between platform operational parameters to the generation of stress at the surface of interest of the ceramic component, determining an initial crack size of a crack within the ceramic component at installation, tracking operational parameters of the platform throughout a course of usage of the ceramic component, calculating the corresponding stress at the crack location due to the tracked operational parameters, and calculating a numerical solution that illustrates a crack growth rate velocity and tracks a size of the crack over time. The ceramic component is replaced based on the crack growth rate velocity and the size of the crack.

Abstract: A method for the detection of failure in a turbomachine by monitoring the performance of the said turbomachine, this being a method in which at least one performance parameter of the turbomachine is measured in order to obtain an actual signature for the performance of the said turbomachine; the actual signature of the said turbomachine is compared with a database of failures associating reference signatures for the performance of the said turbomachine with identifiers of failure, the database of failures being obtained by the simulation of failures on the basis of a theoretical model of the thermodynamic cycle of the said turbomachine, and the identifier of failure of the said turbomachine being determined for the said actual signature.

Abstract: A three-dimensional solid geometry modeling method is described that can move or modify any piece of solid or surface geometry, such as a protrusion or depression, when faces are changed in a way that is not obvious or predictable from the original data. The method involves a combination of local changes and a context-based process that uses simplification, detaching, modification, and reattaching algorithms. The method is invoked automatically when a modeling tool (such as Move or Pull) is used to move or modify a piece of geometry. During the movement or modification, the geometry reflects the changes dynamically as the user interacts with the modeling tool. When performing the modification, simplification of the faces and edges can be manually or automatically invoked.

Abstract: A method, apparatus, and computer program product for identifying associations in a model of a structure. A number of fastener locations is identified in the model of the structure. A line segment extends through each of the number of fastener locations to form a number of line segments. The line segment extends a selected distance away from an associated fastener location in the number of fastener locations. A number of parts is identified through which the line segment extends to form a number of identified parts for a fastener for each of the number of line segments.

Abstract: The purpose of this invention is to reduce the calculation time in the numerical structure analysis system based on load-transfer-path method. The parameters are set in the condition that the supporting point B in the objective structure is fixed and the load is applied to the specific loading point A. The FEM calculation means 2 calculates the deformation of the objective structure according to the structural stiffness matrix in the stiffness matrix holding means 1 to find the basic data such as the displacement of each point and so on. The FEM calculation means calculates each deformation to find the displacement under the condition that the specific loading point A and the supporting point B are fixed and three inspection loadings are applied to the variable loading point C.

Abstract: In a design support apparatus, a storage unit stores location data of an assembly including a first member long and flexible and a second member connected to the first member and having a larger cross-sectional shape than that of the first member within a product, and respective positions of installed objects. A geometric center calculation unit virtually extends straight lines from a point on a route along which the first member passes, radially in directions normal to a tangential direction of the route, virtually positions points where the straight lines come into contact with the installed objects, and calculates a geometric center from the positioned points. A route change unit changes the route such that the first member passes the calculated geometric center. A verification unit verifies whether or not the assembly interferes with any of the installed objects during passage of the first member along the changed route.

Abstract: System and method for co-simulation. A first simulator and a second simulator are included in a co-simulation program. The co-simulation program is executed, including executing the first simulator and the second simulator. During execution, the first simulator receives input from the second simulator and provides output to the second simulator, and the second simulator receives input from the first simulator and provides output to the first simulator. Executing the co-simulation program includes the first simulator and the second simulator negotiating step-size as peers to dynamically synchronize the first simulator and the second simulator.

Abstract: The computation of a Load Factor, a Life Factor or a Load Enhancement Factor using Modified Joint Weibull Analysis may include retrieving a test data set from at least one database and analyzing the data retrieved for fit with a Weibull distribution model. The test data may be analyzed to determine if at least two coupons have been tested and if applied loads and duration of testing at a component-level were varied. A shape parameter may be calculated for the Weibull distribution model. A scale parameter may be calculated for the Weibull distribution of the data. A stress to life cycle relationship may be calculated to account for scatter in the data through the Weibull distribution data. The Life Factor, the Load Factor or the Load Enhancement Factor may be calculated based on the stress to life cycle relationship to account for scatter.

Abstract: Methods for obtaining data and for manufacturing a dental component and a physical dental model of at least a part of a dental structure are provided which can improve processing times and provide sufficient manufacturing accuracy. An embodiment of the method can comprise obtaining a first data record for manufacturing the dental component and a second data record for manufacturing the physical dental model. The first data record can comprise data based on a portion of a digital dental model. The second data record can comprise data based on at least the portion of the digital dental model. In this regard, the data upon which the first and second data records are based can be obtained using first and second scanning resolutions in order to improve processing times and provide sufficient accuracy.

Abstract: Techniques for using air flow analysis to model thermal zones are provided. In one aspect, a method for modeling thermal zones in a space, e.g., in a data center, includes the following steps. A graphical representation of the space is provided. At least one domain is defined in the space for modeling. A mesh is created in the domain by sub-dividing the domain into a set of discrete sub-domains that interconnect a plurality of nodes. Air flow sources and sinks are identified in the domain. Air flow measurements are obtained from one or more of the air flow sources and sinks. An air flow velocity vector at a center of each sub-domain is determined using the air flow measurements obtained from the air flow sources and sinks. Each velocity vector is traced to one of the air flow sources, wherein a combination of the traces to a given one of the air flow sources represents a thermal zone in the space.

Abstract: An FEM analysis system is provided which is capable of analyzing with high accuracy and within a short time in a drop shock analysis of electronic devices in which a very small mesh size is incorporated. Processing to be performed by an optimal solution selecting and analyzing section includes a step of checking whether an analysis to be performed is a shock analysis, a step of searching for a minimum mesh size when the analysis to be performed is judged to be a shock analysis, a step of creating a simplified analysis model using the minimum mesh size, a step of performing a preliminary analysis on a simplified model by an implicit method and explicit method, and a step of selecting either of the implicit method or explicit method as an optimal analysis method by comparing results from preliminary analysis, results from these analyses and experiments or exact solution.

Abstract: A system and method of developing better-designed medical devices, particularly cardiovascular stents and endovascular grafts. The system comprises a geometry generator, a mesh generator, a stress/strain/deformation analyzer, and a visualization tool. In one embodiment, the geometry generator receives three-dimensional volumetric data of an anatomical feature and generates a geometric model. The mesh generator then receives such geometric model of an anatomical feature or an in vitro model and a geometric model of a candidate medical device. In another embodiment, the mesh generator only receives a geometric model of the candidate medical device. Using the geometric model(s) received, the mesh generator creates or generates a mesh or a finite element model. The stress/strain/deformation analyzer then receives the mesh, and the material models and loads of that mesh.

Abstract: A process of using finite element analysis for determining the behavior of a system, submitted to predetermined load and displacement boundary conditions with a degree of freedom relative to a local coordinate system released at one system node. For a geometrically non-linear solution scheme, a plurality of incremental steps are carried, for which computing for a finite element of the system a displacement vector at the nodes of the finite element is performed by minimizing the energy of the system. For a geometrically linear solution scheme, a single solving step is carried. The step of minimizing is carried out, for a node having a released degree of freedom, in a local frame of reference, and the released degree of freedom at the node is expressed along one axis of such frame. Hybrid reference frames allow expressing and considering in the formulation the constraints of the non-released degrees of freedom simply.

Abstract: A system for visualizing a print job includes a print job simulator which applies a print job model to print job image data to generate an image which simulates a rendered image of the print job if the print job were to be printed on a specific marking device. The system also includes a display in communication with the print job simulator for displaying the simulation image. The modified image data displayed on the display enables a customer to see a defect in the print job which would appear if the print job were to be rendered on the specific marking device. The print job model may be derived, at least in part, from information derived from the marking device, such as information derived from image data acquired by scanning a test image which has been rendered by the marking device.

Abstract: A method of estimating information on the projection states of projection elements (P) by using an analysis model in which discharged projection elements (P) repeatedly collided with rotation blades (13) in a projection machine having rotating blades (13). The method includes the steps of determining initial conditions including information on the size and rotation of blades (13), discharging information on the projection elements(P), and information on projection elements with respect to the blades (13) the step of storing the initial conditions, a computing step of computing the position of each projection element (P), and its velocity and direction after collision with a blade(13) based on the initial conditions, and the step of estimating information on projection state based on computation results.

Abstract: A computer-implemented method of characterizing elastic properties of a subsurface formation at various fluid saturation conditions is disclosed.

Abstract: A system and method for providing a layout of equipment in a data center, the equipment including a plurality of equipment racks, and at least one rack-based cooling provider. In one aspect, the method includes receiving data regarding airflow consumption for each of the plurality of equipment racks and cooling capacity of the at least one cooling provider, storing the received data, determining a layout of the data center, and displaying the layout of the data center.

Abstract: A method determines overlap regions by identifying a face on a first component part of an assembly that is less than a specified gap distance from a face on a second component part of the assembly. The method is also for determining if a minimum width of each of one or more the overlap regions exceeds a specified maximum value, and if the minimum width of an overlap region does not exceed the specified maximum value, determining a guide curve along a centerline of the overlap region. If the minimum width of an overlap region exceeds the specified maximum value, the method is further for determining two or more guide curves along an offset of two or more edges of the overlap region. The method also is for determining one or more joint locations along the guide curve or curves based upon one or more parameters.

Abstract: A system for implementing a procedure for the diagnosis or treatment of tissue in a body is provided. The system includes an electronic control unit configured to generate a graphical user interface on a display. The interface depicts an image of the tissue. The unit is further configured to receive one or more inputs regarding target locations on the tissue for diagnosis or treatment. The electronic control unit identifies a catheter for use in the procedure and determines configurations for a distal end of the catheter at each target location. The unit superimposes representations of the distal end of the catheter having the determined configurations on the image of the tissue at the target locations. The unit may also generate control signals to guide the distal end of the catheter to the target locations and to assume the determined configurations at each location.

Abstract: A method and system dynamically generates virtualized configurations of sensors and signals used in drilling system equipment. The virtualized configurations may be used for novel operational testing of automation systems on drilling rigs. The methods and systems may be configured to virtualize actual drill floor equipment in order to have enhanced fault coverage of the automation systems. A control network that is a component of the automation systems may implement a testing loop that accommodates virtualized equipment in a manner substantially similar to actual equipment. In this manner, the testing loop may be configured to control elements specific to the equipment under control, and generate testing results for those specific control elements.

Abstract: Computational systems, methods, and articles of manufacture to predict at least one of residual stresses and distortion in quenched aluminum castings. Residual stresses and distortion may be predicted through incorporating thermal strains induced during quenching with the nonlinear constitutive behavior of quenched microstructures of a quenched aluminum casting, wherein thermal strains arise generally from non-uniform transient temperature distribution of the casting during quenching. The transient temperature distribution of the aluminum casting during quenching may be calculated based on heat transfer coefficients specific to one or more nodes, elements and/or zones on the surfaces of the aluminum casting. The nonlinear constitutive behavior of the quenched aluminum casting may be modeled as functions of temperatures, strain rates, and microstructure variations. A material constitutive model accounts for not only strain hardening and creep, but also precipitate hardening.

Abstract: A finite element analysis (FEA) based coil spring design method that utilizes a reverse engineering based concept. The method involves first designing a desired jounce profile, which is typically an output in the conventional FEA based design, and then reversely determining the corresponding free profile necessary for manufacturing a spring having desired performance specifications.

Abstract: A process for redesigning a distressed component, such as a turbine blade in a gas turbine engine, in which the distressed component is under thermal and structural loads, for improving the life of the component. The process includes obtaining the operating conditions of the machine in which the distressed component is used, finding the boundary conditions under which the distressed component operates, producing a 3-dimensional model of the distressed component with such detail that the distress levels are accurately represented on the model, subjecting the model to a series of technical analysis to predict a life for the component, reiterating the technical analysis until the levels of distress on the model accurately represent the distress that appears on the actual component, and then predicting a remaining life of the component based on the analysis, or redesigning the model and reanalyzing the model until a maximum life for the component has been found.

Abstract: A model may be constructed and simulated using processor-in-the-loop co-simulation at a target device. In one implementation, a host environment may provide a graphical environment that facilitates construction of the model defined as a plurality of functional blocks. The host environment may receive, via graphical selection menus associated with the blocks of the model, an indication of which blocks of the model are to simulated at an external target device and which blocks of the model are to be simulated at the host environment. Further, the host environment may receive a command, that may be entered interactively by a user, to start simulation of the model and execute, in response to the command, co-simulation of the model at the host environment and the external target device.

Abstract: Example in-situ stress measurements in hydrocarbon bearing shales are disclosed. A disclosed example method includes lowering a downhole tool into a wellbore penetrating a subterranean shale formation, logging via the downhole tool, a portion of the wellbore adjacent the shale formation to generate logging results, processing the logging results to select test intervals along the portion of the wellbore, performing a stress test at one or more of the selected test intervals to generate stress test results for the shale formation, and adjusting a model representing at least one property of the shale formation based on the stress test results.

Abstract: A method of simulating a tire rolling on a road at a certain speed by using a computer apparatus 1 comprises the steps of: modeling a flexible tire model 2 for numerical calculation by using finite elements having at least one elastic element (step S1), changing at least one elastic element of the flexible tire model 2 to rigid elements so as to make a rigid tire model 5 (step S6), accelerating the rigid tire model 5 (step S7), returning the elasticity of each element of the rigid tire model 5 into the original elasticity when the speed of the rigid tire model 5 has reached the certain speed (step S8), and obtaining at least one physical parameter related to the flexible tire model 2 (step S10).

Abstract: It is an object of the present invention to provide a machining parameter optimizing apparatus deciding a tool axis attitude and a machining zone and deciding a tooling having high stiffness for any profile of a finished workpiece. A tool axis attitude deciding member 21 decides one or plural tool axis attitude. An interference dangerous zone deciding member 23 decides as an interference dangerous zone a zone possible to interfere between a tool or a tool holder and a workpiece during machining by the decided tool axis attitude. A machining simulation member 25 executes a machining simulation based on the interference dangerous zone by the decided tool axis attitude and generates the virtual tool holder in which there is no any interference, and also decides a machining zone in a way of avoiding the interference dangerous zone.

Abstract: A method of generating a mesh of an object (11) that moves through a fluid medium which is used in the design or analysis of the object (11) in connection with a hybrid method combining RANS and LES comprising the following steps: a) creating an inner “C” topology (21) around the object (11) for a boundary layer description; b) creating an outer “C” topology (23) covering a space region including the separation region; c) locating the separation region and adapting to it the inner and outer “C's” topologies (21, 23) so that the outer “C” topology (23) is adapted to the size of the separated region and the inner “C” topology (21) is adapted to the size of the boundary layer; d) refining the mesh in the separation region according to the specifications of the RANS/LES method. The invention also provides a system for carrying out the method.

Abstract: A method is described to let animators control the extent by which kinematically scripted character motions affect dynamically simulated objects' motions. The dynamic objects are connected to the kinematic character, such as clothing or hair, and the motion of the dynamic objects is simulated based on the motion of the kinematic character. Such control is important to produce reasonable behavior of dynamic objects in the presence of physically unrealistic kinematic character motion. An Inertial Field Generator (IFG) is employed to compensate for the unreasonable behavior of dynamic objects when the kinematic character undergoes unrealistic motion.

Abstract: A method for simulating performance of a golf club head includes dividing a model of the golf club head of a hollow structure using shell elements, and arranging the shell elements on a surface of the model of the golf club head.

Abstract: Methods and systems for numerically predicting surface imperfections on stamped sheet metal parts are disclosed. FEM mesh includes a plurality of shell elements and a plurality of nodes that represents a stamped sheet metal part. At least one surface of the part needs to be examined for imperfection, which can be used for adjusting the die for forming the sheet metal part. Each surface is created by fitting all of nodes of a portion of the FEM mesh in a group-to-group scheme. A group is defined to include a center element and its neighbors. Neighbor elements share a side with the center element are always included in the group. Each group includes at least three neighbors in additional to the center element. Node-sharing elements are added into the group such that the criterion of at least three neighbors is met.

Abstract: The method of modeling flexural characteristics of a bar subjected to local heating utilizes thermal diffusion equations and the finite element method to model vibrational frequency and amplitude variation in a substrate material subjected to local heating. Both heated and non-heated cases are considered.

Abstract: A method for designing a drill bit in an earth formation, including defining parameters for a simulation of the drill bit drilling in earth formation, where the parameters comprise at least bit design parameters; executing the defined simulation; obtaining radial forces resulting from the executing of the defined simulation; applying a criterion to the obtained radial forces; and adjusting one of the at least bit design parameters in response to the applying of the criteria.

Abstract: Method for modeling anisotropic elastic properties of a subsurface region comprising mixed fractured rocks and other geological bodies. P-wave and fast and slow S-wave logs are obtained, and an anisotropic rock physics model of the subsurface region is developed (21). P- and fast and slow S-wave logs at the well direction are calculated using a rock physics model capable of handling fractures and other geological factors (22). Calculated values are compared to measured values in an iterative model updating process (23). An upscaled ID model is developed by averaging elastic properties in each layer using an upscaling theory capable of handling at least orthorhombic anisotropy (24). The ID model may be used to generate synthetic seismic response for well ties or AVO modeling (25). Further, a method is disclosed for estimating anisotropy parameters from P- and fast/slow S-wave logs from one or more deviated wells.

Abstract: In one aspect, the invention provides a method for modeling the performance of a fixed cutter bit drilling an earth formation. In one embodiment, the method includes selecting a drill bit and an earth formation to be represented as drilled, simulating the bit drilling the earth formation, displaying the simulating, and adjusting at least one parameter affecting the performance. The method of design is used to make a fixed cutter drill bit. In another embodiment the method includes numerically rotating the bit, calculating bit interaction with the earth formation during the rotating, and determining the forces on the cutters during the rotation based on the calculated interaction with earth formation and empirical data.

Abstract: Torsional, axial and lateral vibrations introduced when a mud motor is used with a drilling tool to drill a borehole are calculated using a model. The model includes different computational modules for each of three distinct motor sections: power, transmission and bearing. The resulting calculated vibration effects are used to enhance the drilling tool and drilling operation.