Abstract: A liquid crystal display includes: a first electrode and a second electrode disposed on a first substrate, the first electrode and the second electrode being disposed at a same layer; a second substrate facing the first substrate; a third electrode and a fourth electrode disposed on the second substrate and disposed at different layers; and a liquid crystal layer including liquid crystal molecules disposed between the first substrate and the second substrate, wherein the first electrode, the second electrode, and the third electrode each include a plurality of branch electrodes, but the fourth electrode does not; and wherein the first electrode is electrically connected to the third electrode.

Abstract: According to an aspect, a liquid crystal display device includes: a first substrate and a second substrate that face each other; a liquid crystal layer provided between the first substrate and the second substrate; and a first electrode and a second electrode provided between the first substrate and the liquid crystal layer. The first electrode includes: an electrode base portion that extends in a first direction; and a plurality of comb-shaped portions that protrude from the electrode base portion at a fixed distance away from each other, and extend in a second direction different from the first direction. Each of the comb-shaped portions is configured such that a width thereof at a protrusion start position of the electrode base portion is smaller than a number obtained by multiplying an array pitch of adjacent comb-shaped portions by 0.5.

Abstract: A liquid crystal panel, a display device, and a manufacturing method and a driving method thereof are provided. The liquid crystal panel comprises an array substrate (20), a color filter substrate (10), and a liquid crystal layer (30) disposed between two substrates; the array substrate (20) is provided with a first electrode (21) and a second electrode (22) thereon in different layers, the color filter substrate (10) is provided with a third electrode (12) and a fourth electrode (11) thereon in different layers, the first electrode (21) and the third electrode (22) are disposed opposite to each other, the first electrode (21) and the third electrode (12) are slit-like electrodes, the second electrode (22) and the fourth electrode (11) are plate-like electrodes, the first electrode (21) and the third electrode (12) are respectively located on sides close to the liquid crystal layer of the second electrode (22) and the fourth electrode (11).

Abstract: A display device includes a first substrate, a gate driver on array (GOA) circuit, a plurality of peripheral conductive wires, a second substrate, a sealant and a semi-transparent pattern. The GOA circuit is disposed in a gate driver region, and includes a plurality of thin film transistor devices. The peripheral conductive wires are disposed in a peripheral region of the first substrate, and the peripheral conductive wires are electrically connected to the GOA circuit. The sealant is disposed in at least a portion of the peripheral region and a portion of the gate driver region, and the sealant overlaps at least a portion of the peripheral conductive wires and a portion of the thin film transistor devices of the GOA circuit in a vertical direction. The semi-transparent pattern is disposed on the second substrate, and a transmittance of the semi-transparent pattern is between 10% and 80%.

Abstract: A liquid crystal display device having a uniform gap between a TFT substrate and a CF substrate even in cases where a sealant is to be applied to a slim frame formed on the outside of the effective display area is provided. A liquid crystal display device includes an effective display area, a color resist coated area, and a seal area which overlaps the color resist coated area and in which a sealant for sealing liquid crystal is provided, wherein the color resist coated area overlapping the seal area has slits formed therein.

Abstract: A display device including: a substrate including a display area in which pixels are positioned and a peripheral area around the display area; a common electrode and a pixel electrode that are positioned on the display area and overlapping with each other, with a first insulating layer disposed therebetween; a common voltage line positioned on or below the common electrode and contacting the common electrode; an edge common voltage line connected with the common voltage line and formed along an edge of the display area; and a first common voltage transfer line contacting the edge common voltage line in the peripheral area and configured to transfer a common voltage to the common voltage line.

Abstract: There is provided a liquid crystal display panel that improves the reliability of thin film transistors while suppressing a degradation in display quality. A G TFT (120g) connected at its drain electrode (125d) to a G pixel electrode (130g) is disposed on the opposite side of the G pixel electrode (130g) from a B pixel electrode (130b). The distance between a B TFT (120b) connected at its drain electrode (125d) to the B pixel electrode (130b) and the B pixel electrode (130b) is greater than the distance between the G TFT (120g) connected at its drain electrode (125d) to the G pixel electrode (130g) and the G pixel electrode (130g). The distance between an R TFT (120r) connected at its drain electrode (125d) to an R pixel electrode (130r) and the B pixel electrode (130b) is greater than the distance between the B TFT (120b) connected to the B pixel electrode (130b) and the B pixel electrode (130b).

Abstract: A thin film transistor (TFT) array substrate includes a first substrate, a plurality of TFTs formed on the first substrate, a color filter layer covered on the TFTs, and a plurality of pixel electrodes corresponding to the TFTs. The color filter layer is directly formed on the TFTs. The color filter layer includes a plurality of photoresist units. Each of the pixel electrodes is to electrically connected to a drain of the TFT via an opening.

Abstract: We describe a wide band variable transmission optical device having an electronically active cell comprising a guest-host mixture of a liquid crystal host and a dichroic guest dye material contained between a pair of plastic substrates. The liquid crystal host has an axis orientation that is alterable between a clear state orientation and a dark state orientation and the dichroic guest dye material includes one or more dichroic dyes. The optical device is characterized in that it exhibits a wide absorption band that is greater than 175 nm within a visible wavelength range of 400-700 nm, has a clear state transmission equal to or above 30% and a dark state transmission equal to or below 40%.

Abstract: Methods of manufacturing electrochromic windows are described. An electrochromic device is fabricated to substantially cover a glass sheet, for example float glass, and a cutting pattern is defined based on one or more low-defectivity areas in the device from which one or more electrochromic panes are cut. Laser scribes and/or bus bars may be added prior to cutting the panes or after. Edge deletion can also be performed prior to or after cutting the electrochromic panes from the glass sheet. Insulated glass units (IGUs) are fabricated from the electrochromic panes and optionally one or more of the panes of the IGU are strengthened.

Abstract: The present invention provides uniformly electrified electret fine particles having excellent electrophoretic properties. Specifically, the present invention provides a core-shell electret fine particle comprising a core part and a shell part, the core part containing a material that has an ability to disperse a pigment therein, the shell part containing an electret resin, and the electret resin being a fluorine-containing resin and being electretized by electron ray irradiation, radial ray irradiation, or corona discharge treatment.

Abstract: The present invention provides a full color display device in which each pixel can display multiple high-quality color states. More specifically, an electrophoretic fluid is provided which comprises four types of particles, dispersed in a solvent or solvent mixture and each pixel can display at least five different color states.

Abstract: A constitution of the display device of the invention is shown in the following. The display device includes a pixel unit including TFTs of which the active layer contains an organic semiconductor material for forming channel portions in the opening portions in an insulating layer arranged to meet the gate electrodes. The pixel unit further includes a contrast media formed on the electrodes connected to the TFTs for changing the reflectivity upon the application of an electric field, or microcapsules containing electrically charged particles that change the reflectivity upon the application of an electric field. The pixel unit is sandwiched by plastic substrates, and barrier layers including an inorganic insulating material are provided between the plastic substrates and the pixel unit. The purpose of the present invention is to supply display devices which are excellent in productivity, light in weight and flexible.

Abstract: Embodiments of the present disclosure provide techniques and configurations for a display apparatus. In one embodiment, the apparatus may include one or more micro-electro-mechanical system (MEMS) devices. The MEMS device may include a first electrode including a partially reflective surface, a second electrode including a partially or completely reflective surface and disposed substantially parallel to the first electrode, and an analog actuation arrangement coupled to the first electrode, the second electrode or both the first and second electrodes to cause movement of the first electrode from a start position to a selected position of a plurality of end positions, responsive to a selected application of an actuation voltage, to cause the MEMS device to selectively output a reflection of a light in a selected wavelength, or no reflection of the light. Other embodiments may be described and/or claimed.

Abstract: An optical semiconductor element includes a ring modulator, and a light absorbing material provided at a position apart from a path for a modulated light which is guided by the ring modulator, the light absorbing material absorbing a light leaked out of a ring waveguide of the ring modulator, and increasing a temperature of the ring waveguide.

Abstract: An optical semiconductor element includes a ring modulator, and a light absorbing material provided at a position apart from a path for a modulated light which is guided by the ring modulator, the light absorbing material absorbing a light leaked out of a ring waveguide of the ring modulator, and increasing a temperature of the ring waveguide.

Abstract: This disclosure provides a second harmonic generator and an optical parametric oscillator, the second harmonic generator and the optical parametric oscillator comprise one or more nonlinear optical frequency conversion crystal and a pump laser source, the nonlinear optical frequency conversion crystal is a monoclinic Ga.sub.2S.sub.3 crystal, the space group of the monoclinic Ga.sub.2S.sub.3 crystal is Cc, and the unit cell parameters are a=11.1.ANG., b=6.4.ANG., c=7.0.ANG., .alpha.=90.degree., .beta.=121.degree., .gamma.=90.degree., and Z=4.

Abstract: A focal plane shutter includes: a board including an opening; a leading blade and a trailing blade opening and closing the opening; a trailing blade actuator driving the trailing blade; a drive member driving the trailing blade by receiving driving force of the trailing blade actuator; and a buffering member abutting with the drive member in a state where the trailing blade recedes away from the opening, wherein the trailing blade actuator causes the drive member to move away from the buffering member from an abutting state therewith and to abut therewith again in a charging operation, and then starts an exposure operation.

Abstract: An optical imaging lens for a mobile device comprising four lens elements positioned sequentially from an object side to an image side. By controlling the convex or concave shape of the surfaces of the lens elements, the optical imaging lens may exhibit better optical characteristics. Furthermore, the total length of the optical imaging lens may be shortened.

Abstract: A camera system is configured to detachably couple to a camera mount, which in turn can be attached to an apparatus such as a sports board. The camera mount includes a top mount portion and a bottom screw portion. The top mount portion includes a buckle component that can detachably couple to a camera system, and includes blade components having cutting edges that can cut through a sports board. The blade components surround a screw hole component, and when the blade components have pierced a surface of the sports board and cut through the board, an opening to the screw hole component is accessible from the underside of the board surface. The bottom screw portion includes a screw thread that can be inserted and screwed into the screw hole component, thus securing the camera mount to the sports board.

Abstract: A device comprising a harness, an arm, and an extendable string. The arm may include a first portion being fixed in relation to the harness and a second portion for supporting of the string. The string may include a first portion and a second portion, the first portion of the string being arranged for fastening of an optical instrument. The device may include an adjustable counter force device, and the second portion of the string may be attached to the adjustable counter force device for providing a counter force on the string. The adjustable counter force device may include a spring, a lever arm, and a support. The counter force exerted by the counter force device on the string may be adjustable.

Abstract: A portable studio unit includes a first main body portion configured to define any one plane among three axes planes constructing a three dimensional figure, a second main body portion connected to the first main body portion, a third main body portion located at an opposite side of the second main body portion with the first main body portion interposed therebetween, and pairs of side surface finishing portions arranged at side surfaces of the three dimensional figure corresponding to open regions defined by the first main body portion, the second main body portion and the third main body portion except for a front surface.

Abstract: There is provided a projector comprising: a polyhedral main body portion made up of a plurality of surfaces which includes a projection unit; and a support plate which has substantially the same size as that of a first surface of the plurality of surfaces of the main body portion and which is detachably attached to the first surface, wherein the support plate has in a substantially central portion a fixing portion to which a second surface of the plurality of surfaces which is smaller than the first surface is fixed, and wherein when the main body portion is placed on the support plate in such a way that the second surface functions as a bottom surface, the second surface of the main body portion is fixed to the fixing portion of the support plate, whereby the main body portion is allowed to stand alone.

Abstract: To provide a projector which enables a stable projection for a long period of time, there is provided a projector comprising a light source unit, a display device, a projection-side optical system, a light guiding optical system and a projector control unit, wherein the light source unit comprises an excitation light source unit comprising an excitation light source and a microlens array and a rectangular green luminescent plate which receives light emitted from the excitation light source to emit light in a green wavelength band, and the microlens array is disposed between the excitation light source and the luminescent plate and has a plurality of micro convex lenses which each have a similar shape to the shape of the luminescent material layer are arranged into a matrix, so as to convert light from excitation light source into a plurality of pencils of light to shine them onto the luminescent plate.

Abstract: There is disclosed a laser projection display including a light source unit for emitting light laser light; a light resolution unit for resolving the laser light into a first light and a second light; an optical scanner for realizing an image by scanning the resolved first light to a screen; a sensing unit for sensing the resolved second light; and an alignment compensation unit for calculating location variation of the second light sensed by the sensing unit and compensating color alignment to correspond to the calculated location variation value, wherein a distance between a light emitting surface of the light resolution and a light incidence surface of the optical scanner is equal to a distance between a light emitting surface of the light resolution unit and a light incidence surface of the sensing unit.

Abstract: A curved back-projection screen having an angle of curvature greater than 180° is described such as a wrap-around cylindrical or dome screen. The screen includes a first layer and a second synthetic resin diffusing layer on the first layer, the second synthetic resin diffusing layer containing a light absorbing material and light diffusing particles embedded in a resin material, with the second synthetic resin diffusing layer having a value of the product of the absorption coefficient and thickness of between 0.1 and 2. The second synthetic resin diffusing layer can be applied by spraying.

Abstract: A first embodiment is a lithography mask comprising a transparent substrate and a first molybdenum silicon nitride (MoxSiyNz) layer. The first MoxSiyNz layer is over the transparent substrate. A percentage of molybdenum (x) of the first MoxSiyNz layer is between 1 and 2. A percentage of silicon (y) of the first MoxSiyNz layer is between 50 and 55. A percentage of nitride (z) of the first MoxSiyNz layer is between 40 and 50. The first MoxSiyNz layer has an opening therethrough.

Abstract: A method for forming a non-deformable patterned template includes providing a stable mesh, wherein the stable mesh is resistant to deformation; providing a curable liquid polymer; placing the stable mesh in the curable liquid polymer such that the stable mesh is completely enclosed within the liquid polymer; curing the liquid polymer to form a polymer sheet with the stable mesh embedded therein; and forming a surface pattern on at least one of the faces of the polymer sheet, the surface pattern including at least two fiducial marks.

Abstract: Provided is a colored photo-sensitive composition having a high sensitivity and a good developablity, even if the ratio of content of a pigment, relative to the total solids of the colored photo-sensitive composition, is 20% by mass or more. The colored photo-sensitive composition includes (A) a resin which is increased, by action of an acid, in solubility into an alkali developing solution; (B) a pigment; (C) a compound which produces an acid upon irradiated by active light or radial ray; and (D) a solvent, wherein the ratio of content of the (B) pigment, relative to the total solids of the colored photo-sensitive composition, is 20% by mass or more.

Abstract: A compound represented by the following formula (I), wherein R1 is a hydrogen atom, a halogen atom, a methyl group or a trifluoromethyl group.

Abstract: Disclosed are a monomer for a hardmask composition represented by the Chemical Formula 1, a hardmask composition including the monomer, and a method of forming a pattern using the same.

Abstract: The pattern forming method of the present invention includes (i) forming a film using an actinic ray-sensitive or radiation-sensitive resin composition which contains a resin (A) which has a repeating unit including a group capable of generating a polar group by being decomposed due to an action of an acid and a repeating unit including a carboxyl group, a compound (B) which generates an acid according to irradiation with actinic rays or radiation, and a solvent (C); (ii) exposing the film using a KrF excimer laser, extreme ultraviolet rays, or an electron beam; and (iii) forming a negative tone pattern by developing the exposed film using a developer which includes an organic solvent.

Abstract: A radiation-sensitive resin composition includes a first polymer including an acid-labile group, an acid generator to generate an acid upon exposure to radiation, and a second polymer including a fluorine atom and a functional group shown by a general formula (x). The second polymer has a fluorine atom content higher than a fluorine atom content of the first polymer. R1 represents an alkali-labile group. A represents an oxygen atom, —NR?—, —CO—O—# or —SO2—O—##, wherein the oxygen atom represented by A is not an oxygen atom bonded directly to an aromatic ring, a carbonyl group, or a sulfoxyl group, R? represents a hydrogen atom or an alkali-labile group, and “#” and “##” each indicate a bonding hand bonded to R1.

Abstract: A compound represented by formula (I): wherein R1 represents a hydrogen atom, a halogen atom, or a C1-C6 alkyl group which may have a halogen atom; R2 and R3 each independently represent a hydrogen atom or a C1-C6 monovalent saturated hydrocarbon group, and R4 represents a C1-C6 monovalent saturated linear hydrocarbon group, a C3-C6 monovalent saturated branched hydrocarbon group, a C5-C12 monovalent alicyclic hydrocarbon group or a C5-C12 monovalent alicyclic hydrocarbon-containing group, or R3 and R4 represent a C2-C6 heterocyclic ring together with an oxygen atom and a carbon atom; A1 represents a single bond, or *-A2-X1-(A3-X2)a— where A2 and A3 each independently represent a C1-C6 alkanediyl group, X1 and X2 each independently represent an oxygen atom, a carbonyloxy group or an oxycarbonyl group, and “a” represents 0 or 1; A4 represents a C1-C6 alkanediyl group; Ad represents a divalent adamantanediyl group.

Abstract: A positive resist composition comprising an organosiloxane-modified novolak resin, a photosensitive agent, and an organic solvent is provided, the resin comprising structural units having formula (1) wherein R1 is an organosiloxy group, and R2 is hydrogen or alkyl. The composition is photosensitive, turns alkali soluble in the exposed region, eliminates any film thickness loss after development, and displays improved resistance to electrolytic plating and O2 dry etching.

Abstract: A process is provided for printing a high resolution pattern on a photopolymeric surface.

Abstract: A composite mask suitable for multiple-patterning lithographic processes and a multiple-patterning photolithographic process utilizing the mask are disclosed. An exemplary embodiment includes receiving a mask having a plurality of sub-reticles and a substrate having one or more regions. A first sub-reticle of the plurality of sub-reticles is aligned with a first region of the one or more regions. A movement pattern is designated relative to the substrate. A first photolithographic process is performed including exposing the substrate using the mask to form a first exposed area on the substrate. An alignment of the mask relative to the substrate is shifted according to a first direction determined by the movement pattern. A second photolithographic process is performed including exposing the substrate using the mask to form a second exposed area on the substrate such that the second exposed area overlaps the first.

Abstract: A method is disclosed to form a patterned epitaxy template, on a substrate, to direct self-assembly of block copolymer for device lithography. A resist layer on a substrate is selectively exposed with actinic (e.g. UV or DUV) radiation by photolithography to provide exposed portions in a regular lattice pattern of touching or overlapping shapes arranged to leave unexposed resist portions between the shapes. Exposed or unexposed resist is removed with remaining resist portions providing the basis for a patterned epitaxy template for the orientation of the self-assemblable block copolymer as a hexagonal or square array. The method allows for simple, direct UV lithography to form patterned epitaxy templates with sub-resolution features.

Abstract: A microporous carbon scaffold is produced by lithographically patterning a carbon-containing photoresist, followed by pyrolysis of the developed resist structure. Prior to exposure, the photoresist is loaded with a nanoparticulate material. After pyrolysis, the nanonparticulate material is dispersed in, and intimately mixed with, the carbonaceous material of the scaffold, thereby yielding a carbon composite structure.

Abstract: The present invention provides a method for manufacturing a suspended single carbon nanowire and piled nano-electrode pairs, and a suspended single carbon nanowire and piled nano-electrode pairs manufactured using said method. A suspended single carbon nanowire, which is manufactured at a high yield by the method for manufacturing a suspended single carbon nanowire according to the present invention, has a minimized dimension, and a suspended carbon nanomesh, which is manufactured at a high yield by the method for manufacturing piled nano-electrode pairs according to the present invention, is thin and dense. The present invention also provides a gas sensor or an electrochemical sensor, to which a suspended single carbon nanowire and piled nano-electrode pairs manufactured by the method according to the present invention are applied.

Abstract: A method of process chemical temperature control for resist stripping of a substrate in a resist stripping system includes selecting at least two temperature control objectives and selecting at least two temperature control operating variables for optimization to achieve the at least two temperature control objectives. The method further includes injecting and mixing a first process chemical and a second process chemical into a treatment liquid delivery system of the resist stripping system, which forms a treatment liquid including an active species. The method further includes injecting vapor into the treatment liquid delivery system. The vapor is injected into the treatment liquid or the treatment liquid is injected into the vapor. Treatment liquid is dispensed from the dispensing device onto the substrate. At least two of the temperature control operating variables are adjusted in response to at least two metrology data values.

Abstract: According to one embodiment, a method for manufacturing a reflective mask includes: forming a reflection layer on a major surface of a substrate; forming a capping layer containing ruthenium on the reflection layer; forming an absorption layer on the capping layer; forming a pattern region in the absorption layer; removing a first resist mask used in forming the pattern region; and forming a light blocking region surrounding the pattern region in the absorption layer, the capping layer, and the reflection layer. The removing the first resist mask used in forming the pattern region includes: performing dry ashing processing using a mixed gas of ammonia gas and nitrogen gas or only ammonia gas.

Abstract: An exposure apparatus irradiates a substrate with light via a projection system and liquid, and includes a stage that moves below the projection system, and a light-receiving element having a light-receiving surface. An optical member provided on the stage has a first surface contacting the liquid when moved to face the projection system, and a second surface contacting a gas and transmitting light having come from the projection system via the liquid and the first surface. The optical member is configured such that at least a large-angle ray of the light, which has an angle with an optical axis of the projection system sufficiently large to undergo total reflection at an end surface of the projection system when the liquid is absent, travels from the projection system to the second surface without passing through gas. The second surface transmits the large-angle ray, which is received by the light-receiving surface.

Abstract: An objective lens system having a high numerical aperture, a large working distance, and low optical aberrations over a wide spectral band of wavelengths is disclosed. The objective lens system includes a first lens group, a second lens group, and a third lens group. The first lens group includes first and second positive meniscus lenses that are positioned at a distance from each other along an optical axis of the objective lens system. The distance may be dependent on a focal length of the objective lens system. The second lens group includes first and second meniscus lenses and a bi-convex lens. The third lens group includes a bi-concave lens and a doublet lens.

Abstract: An illumination optical system can form a pupil intensity distribution with a desired beam profile. The illumination optical system for illuminating an illumination target surface with light from a light source is provided with a spatial light modulator which has a plurality of optical elements arrayed on a predetermined surface and individually controlled and which variably forms a light intensity distribution on an illumination pupil of the illumination optical system; a divergence angle providing member which is arranged in a conjugate space including a surface optically conjugate with the predetermined surface and which provides a divergence angle to an incident beam and emits the beam; and a polarizing member which is arranged at a position in the vicinity of the predetermined surface or in the conjugate space and which changes a polarization state of a partial beam of a propagating beam propagating in an optical path.

Abstract: A lithographic apparatus having a plurality of individually controllable radiation source units each providing a portion of a patterned beam of radiation, a control system configured to monitor a parameter of performance of each of the individually controllable radiation source units, and a replacement mechanism configured to replace one of the individually controllable radiation source units with a replacement unit responsive to the control system determining that a criterion has been met based on the monitored parameter of performance.

Abstract: A projection exposure apparatus for microlithography for the production of semiconductor components includes at least one optical assembly with at least one optical element which can be actuated in a mechanically controlled manner is mounted in a structure. For carrying out the mechanical actuation, a control signal transmission device and/or an energy transmission device are/is provided, which introduce(s) no parasitic mechanical effects into the optical assembly at least during specific operating states of the projection exposure apparatus.

Abstract: An exposure head according to the invention includes: a transparent substrate; a plurality of exposure light sources which is formed in the transparent substrate and emits exposure light; at least one condensing lens which condenses the exposure light from the exposure light sources on the exposure object; an imaging unit which is disposed on the opposite side to the condensing lens with the transparent substrate interposed therebetween and images the exposure object; and a control unit which controls the turning on of the exposure light sources based on image information imaged by the imaging unit. An exposure device according to the invention includes the exposure head according to the invention. By virtue of such a configuration, it is possible to improve alignment precision of the exposure object and to improve exposure precision of the exposure object.

Abstract: Provided is an exposure method that includes setting a first exposure condition so as to calculate a coefficient for predicting the fluctuation in the imaging characteristics of the projection optical system under a certain exposure condition; determining the coefficient and a permissible value calculated from aberration measurement reproducibility based on a fluctuation characteristic model; calculating a predicted amount of the fluctuation in the imaging characteristics under the first exposure condition based on the coefficient; determining whether or not the predicted amount is less than the permissible value for each time instant; and starting calculation of the predicted amount of the fluctuation in the imaging characteristics under a second exposure condition at the time at which it is determined by the determining that the predicted amount is less than the permissible value.

Abstract: Systems and methods for providing improved scanner corrections are disclosed. Scanner corrections provided in accordance with the present disclosure may be referred to as wafer geometry aware scanner corrections. More specifically, wafer geometry and/or wafer shape signature information are utilized to improve scanner corrections. By removing the wafer geometry as one of the error sources that may affect the overlay accuracy, better scanner corrections can be obtained because one less contributing factor needs to be modeled.