An image forming method includes the steps of a) multi-level quantizing a multi-tone image by an error diffusion method, and b) representing each pixel of the thus-quantized image having a quantized level higher than 0 using a dot which is larger as the quantized level thereof is higher. Occurrence of dots having a specific size is repressed in a specific shade region relating to the dots.

1. Field of the Invention
The present invention generally relates to an image forming method, an image processing method and an image processing apparatus using an error diffusion method in multi-level quantization for multi-tone images.
2. Description of the Related Art
For example, in laser printers, digital copiers, display devices, and other various image processing apparatuses, an error diffusion method has been widely used for falsely reproduicng tones of multi-tone images.
With regard to the error diffusion method, the following various improvements have been proposed:
(1) In a system in which image data is two-level quantized according to the error diffusion method, in order to improve continuity of characters and figures, a configuration (continuity) of ON dots output in the periphery of a target pixel is examined, and a quantization threshold is controlled so that an output dot of the target pixel is easily to generate an ON dot when ON dots continue in a certain direction (Japanese Patent Publication No. 8-24338);
(2) In a system in which image data is two-level quantized according to the error diffusion method, in order to prevent a peculiar texture due to close placement of ON dots due to error diffusion in a positive direction from occurring in a light shade portion, a quantization threshold is controlled so that an output dot of a target pixel is determined to be an OFF dot when ON dots are output in the periphery of the target dot in a light shade portion (Japanese Patent No. 2662402); and
(3) Continuity of output dots in the periphery of a target pixel is examined, and a quantization threshold is controlled so that continuity of ON dots or OFF dots is avoided so that chain-like textures and false contours are prevented from being generated (Japanese Patent No. 2756308).

Image processing method, image processing apparatus, image forming method and recording medium


An inverter control unit includes a variable-tap-added step-down transformer. A DC energy unit is connected to a DC side of an inverter unit for supplying or consuming effective power. A control circuit controls a variable tap of the variable-tap-added step-down transformer. The control circuit includes a calculating circuit for calculating an effective value of a system voltage. A setting circuit sets an effective value command value. A deviation calculating circuit calculates a deviation between the effective value and the effective value command value. A tap command circuit operated by the system voltage outputs a tap command value corresponding to the deviation. A tap change judging circuit determines whether an inverter current at least equal to a rated value is output with a change in the variable tap. A tap command circuit changes the tap command value on the basis of the determination of the tap change judging circuit. A tap command value selecting circuit selects any one of the two tap command values. A tap changing circuit changes the variable tap on the basis of the tap command value selected by the tap command value selecting circuit.

1. Field of the Invention
The present invention relates to an inverter control unit that controls active power and/or reactive power.
2. Description of the Related Art
FIG. 4 shows a step-down transformer referred to as a "receiving transformer" and an inverter unit referred to as an "active filter", in Mitsubishi Electric Technical Report, Vol. 65, No. 6, 1991, "Arc Furnace Flicker Compensating Large-Capacitance Active Filter", p. 62 (582). FIG. 4 is a single phase wiring diagram showing FIG. 6 of the referenced publication without a higher harmonic filter and an arc furnace load.
In FIG. 4, reference numeral 5 denotes an invertor unit; 1, an a.c.-d.c. transformer of the inverter unit 5; 2, an inverter transformer of the inverter unit 5; 4, a system voltage source; and 3, a step-down transformer with a variable tap which links the inverter unit 1 to the system voltage source 4. The tap of the step-down transformer 3 is variably controlled by a control circuit 10. Reference numeral 6 denotes a d.c. capacitor of the inverter unit 5.
Reference numeral 7 denotes a d.c. energy unit connected to a d.c. side of the inverter unit 7 that supplies or consumes power to the inverter unit 5. The d.c. energy unit 7 is designed, for example, as follows:
a) a d.c. capacitor circuit; PA1 b) a d.c. circuit connected directly to a d.c. energy storage means such as a battery; PA1 c) a d.c. circuit connected indirectly to a d.c. energy storage means such as a battery, a chopper circuit and so on, and whose d.c. voltage is controlled to be constant; PA1 d) a d.c. circuit that can be charged from an external power supply; PA1 e) a d.c. circuit that can be discharged by a resistor or the like; PA1 f) a d.c. circuit of an inverter unit whose a.c. side is connected to a power generator or the like; PA1 g) a d.c. circuit of an inverter unit whose a.c. side is connected to an electric motor having an energy storage means such as a flywheel; and PA1 h) a transformer and a rectifier circuit having a an AVR (automatic voltage regulation) function.
FIG. 5 shows an example of the control circuit 10 that actuates the variable tap of the step-down transformer 3 with the variable tap.
In FIG. 5, reference numeral 11 denotes an effective value calculating circuit that calculates the effective value of a system voltage V.sub.0 ; 12, a setting circuit for setting an effective value command value V.sub.0 * of the system voltage V.sub.0 ; 13, a deviation calculating circuit for calculating a deviation .DELTA. V.sub.0 between the effective value and a command value V.sub.0 * of the system voltage V.sub.0 ; 14, a tap command circuit for instructing a change in tap position corresponding to the system voltage deviation .DELTA. V.sub. ; and 18, a tap changing circuit for comparing an output of the tap command circuit 14 with a current tap to change the tap position of the step-down transformer 3 with a time delay element.
Then, the operation will be described.
The system voltage V.sub.0 steadily goes up or down, for example, 5% of a rated voltage V.sub.0, according to the operating state of a load connected to the system voltage source 4. In this state, a deviation between an output value from the effective value calculating circuit 11 for the system voltage V.sub.0 and the effective value command value V.sub.0 * from the setting circuit 12 is calculated by the deviation calculating circuit 13. A tap position corresponding to the system voltage deviation .DELTA. V.sub.0 is commanded from the tap command circuit 14, and the tap command value outputted from the tap command circuit 14 is compared with the current tap position for changing the tap with the time delay by the tap changing circuit 18. As a result, the step-down transformer 3 with a variable tap changes the voltage tap position with a load connected so that a secondary voltage V.sub.s is restrained to within a tap width .DELTA. V.sub.s.
FIG. 6 shows a single phase wiring diagram of the step-down transformer 3 with a variable tap for one phase.
When the system voltage V.sub.0 is equal to rated voltage, the variable tap produces a tap voltage V.sub.k shown in FIG. 6, but when the system voltage V.sub.0 steadily goes up and is higher than a rated value, the variable tap is gradually moved toward V.sub.1 shown in FIG. 6, step by step, in predetermined time intervals, and is controlled in such a manner that a secondary voltage V.sub.s is restrained within a given range of the rated voltage.
On the other hand, when the system voltage V.sub.0 steadily goes down and is lower than the rated value, the variable tap is gradually moved toward V.sub.2 shown in FIG. 6 step by step, in predetermined time intervals, and is controlled in such a manner that the secondary voltage V.sub.s is restrained within a given range of the rated voltage.
The a.c.-d.c. convertor 1 of the inverter unit 5 variably controls the fundamental wave voltage magnitude and the phase of an inverter voltage V.sub.a inputted through the inverter transformer 2 with respect to the fundamental wave voltage magnitude and the phase of the secondary voltage V.sub.s of the step-down transformer 3 with a variable tap. For facilitation of description, it is assumed that the winding ratio of the inverter transformer 2 is set to 1:1, and the magnitude of the secondary voltage V.sub.s is equal to the magnitude of the inverter voltage V.sub.a when the inverter current I.sub.a inputted through the invertor transformer 2 is zero.
Since a difference voltage magnitude .DELTA. V.sub.xa =V.sub.a -V.sub.s of the inverter voltage magnitude V.sub.a and the secondary voltage magnitude V.sub.s is applied to the inverter transformer 2 having an inductance X.sub.a, an magnitude I.sub.a inverter is obtained by dividing the difference inverter current value .DELTA. V.sub.xa by the inductance X.sub.a is generated. In this situation, the phase of the inverter current I.sub.a is delayed with respect to the difference voltage, .DELTA. V.sub.xa, by 90 degrees.
The magnitude and the phase of the inverter voltage V.sub.a generated by the inverter unit 5 is variably controlled according to a direction along which the active power and/or the reactive power flows. When the difference voltage .DELTA. V.sub.xa is identical in phase with the secondary voltage V.sub.s, the inverter voltage V.sub.a increases in magnitud by (V.sub.s +.DELTA.V.sub.xa), and the inverter current I.sub.a is advnaced in phase by 90 degrees from secondary voltage V.sub.s, resulting in a capacitor operation where the phase-advanced reactive power is generated.
When the difference voltage .DELTA. V.sub.xa is shifted in phase from the secondary voltage V.sub.s by about 180 degrees, the inverter voltage V.sub.a decreases in magnitude by (V.sub.s -.DELTA. V.sub.xa), and the inverter current Ia is delayed in phase by 90 degrees from the secondary voltage V.sub.s, resulting in a reactor operation where phase-delayed reactive power is generated.
Also, when the difference voltage .DELTA. V.sub.xa is generated so that the inverter current Ia is in phase with the secondary voltage V.sub.s, the inverter voltage V.sub.a becomes .sqroot.(V.sub.s.sup.2 +.DELTA. V.sub.xa.sup.2), resulting in a converter operation where active power flows from the invertor unit 5.
When the difference voltage .DELTA. V.sub.xa is generated so that the invertor current I.sub.a is different in phase from the secondary voltage V.sub.s by about 180 degrees, the inverter voltage V.sub.a becomes .sqroot.(V.sub.s.sup.2 +.DELTA. V.sub.xa.sup.2), resulting in an inverter operation where active power flows from the invertor unit 5.
The inverter rated voltage V.sub.a0 is defined as the inverter voltage V.sub.a when the inverter current I.sub.a is zero, and the capacitance of the inverter is defined by a product of the inverter current I.sub.a and the inverter rated voltage V.sub.a0.
The relational expression (1) of the d.c. voltage E.sub.d and the inverter rated voltage V.sub.a0 of the inverter unit 5 is as follows: EQU E.sub.d .gtoreq.K.times..sqroot.2.times.V.sub.a0 .times..sqroot.((1+X.sub.a .multidot.I.sub.a .multidot.cos .theta.).sup.2 +(X.sub.a .multidot.I.sub.a .multidot.sin .theta.).sup.2) (1)
where sin .theta.=i.sub.p/.sqroot.(i.sub.p.sup.2 +i.sub.q.sup.2), cos .theta.=i.sub.q/.sqroot.(i.sub.p.sup.2 +i.sub.q.sup.2), and I.sub.a =.sqroot.(i.sub.p.sup.2 +i.sub.q.sup.2) are defined; .theta.=0.degree. is the convertor operation, .theta.=90.degree. is the capacitor operation, .theta.=180.degree. is the inverter operation, and .theta.=270.degree. is the reactor operation; and i.sub.p (>0) is the current of the converter operation, i.sub.q (>0) is the phase-advanced reactive current of the capacitor operation, i.sub.p (<0) is the current of the inverter operation, and i.sub.q (<0) is the reactive current of the reactor operation.
Also, a constant K is a constant determined by the structure or the control performance of the inverter unit 5. K>1 is normally satisfied, for example, K=1.2, but since it is a constant irrelevant to the subject matter of the present invention, K=1, which is an ideal state, is assumed.
Of the capacitor operation, the reactor operation, the converter operation and the inverter operation by the inverter unit 5, the inverter voltage magnitude Va or a peak value (.sqroot.2.times.V.sub.a) becomes maximum during the capacitor operation.
At the time of the capacitor operation, from the relational expression (1) when .theta.=90.degree., the following expression is satisfied. EQU E.sub.d .gtoreq..sqroot.2.times.V.sub.a0 .times.(1+X.sub.a .multidot.I.sub.q) (2)
If an upper limit I.sub.q1 of the generatable phase-advanced reactive current I.sub.q is a controllable maximum current or less of a power semiconductor device (hereinafter referred to as "device"), such as GTO or IGBT as a conversion element of the a.c.-d.c. converter 1, the following expression is satisfied. EQU I.sub.q1 =(E.sub.d /(.sqroot.2.times.V.sub.a0)-1)/X.sub.a (3)
At the time of the converter operation or the inverter operation, the following expression is satisfied from the expression (1) at .theta.=0.degree. or 180.degree.. EQU E.sub.d .gtoreq..sqroot.2.times.V.sub.a0 .times..sqroot.(1+(X.sub.a .multidot.I.sub.p).sup.2) (4)
If an upper limit I.sub.p1 of the generatable effective current I.sub.p is a controllable maximum current or less of the device, the following expression is satisfied. EQU I.sub.p1 =(.sqroot.((E.sub.d /(.sqroot.2.times.V.sub.a0)).sup.2 -1))/X.sub.a(5)
The d.c. voltage E.sub.d of the inverter unit 5 is a constant determined by a device rated voltage or the structure of the inverter unit 5 such as the number of series connections. In the case where the inverter voltage peak value (.sqroot.2.times.V.sub.a0) is designed to be a value having no margin with respect to the inverter d.c. voltage E.sub.d, for example, in case of E.sub.d /(.sqroot.2.times.V.sub.a0)=1.1,X.sub.a=0.2, the magnitude .vertline.i.sub.q1 .vertline. of the phase-advanced reactive current cannot equal the current magnitude value .vertline.i.sub.p1 .vertline. such that I.sub.p1 =2.3 when I.sub.q1 =0.5.
In the conventional inverter control unit thus structured, since a reactive power higher than the rated reactive power determined in design cannot be obtained, the structure per se of the inverter is required to be enlarged, for example, by increasing the device rated voltage and the number of connected devices to increase the d.c. voltage.
Also, there arises a problem that an active power higher than the rated effective power determined in design cannot be obtained, etc.


On the rotor, between each blade integral with its folding mount and the member for linking with the hub, an electrical connecting cable comprises a first section of which one part is held, in any position of the blade about the folding axis, above the mount and the radially outer end of the link member on which the mount pivots, in an off-centered position with respect to the folding axis and on the side towards which the blade is designed to be folded. This holding is provided by a cable support tied to the folding pivot and on which an arm, receiving the held part of this section of cable, is mounted in cantilever manner on the folding side.

The invention relates to a rotary-wing aircraft rotor, whose blades are automatically foldable and equipped with electrical equipment, such as de-icing or anti-icing equipment, or even positioning lights or lamp(s) at the blade ends, or an electrical actuator to control a mobile member such as a blade flap, or any other electrical equipment requiring the routing of electrical energy to the blades from an electrical collector placed at the center of the hub of the rotor. This routing of electrical energy is provided by an electrical connection installation, essentially comprising an electrical harness comprising, for each blade, at least one electrical connecting cable, tied to a member for linking the corresponding blade to the hub of the rotor, and provided at its ends with connectors to ensure an electrical connection between the collector and the blade.
More precisely, the invention relates to a rotary-wing aircraft rotor, in particular a helicopter main rotor, of the type known in particular by EP-0 754 623 and FR 2 781 198 and comprising:
a hub, designed to be driven in rotation about an axis of the hub which is the axis of rotation of the rotor,
at least two blades, each of which is connected to the hub by a link member that is substantially radial with respect to the axis of rotation, each blade being firmly connected by its root to a folding mount, mounted in a pivoting manner at a radially outer end of the said link member, about an axis for folding the said blade between two positions, one of which is a flight position, in which the said mount is attached to the said link member in such a way that the said blade is substantially aligned in the projection of the said link member, and the other of which is a position folded along one side of the rotary-wing aircraft, in which the said mount and blade are pivoted about the said folding axis on one side of the said link member, and
an electrical connection installation comprising, for each blade, at least one electrical connecting cable connecting a first connector, carried by the hub and electrically connected on the latter, to a second connector on the blade and connected to at least one electrical device of the said blade.
On a rotor according to EP 0 754 623, the connecting cable, for each automatically foldable blade, comprises (see FIGS. 7 and 13) a first section, radially towards the outside, arranged like an overhead hook and extending from this blade to the corresponding link member, and connecting the second connector on this blade to a rotating part, with which this first section is integral in rotation, of a rotating connector coaxial with the folding spindle about an extension of this spindle, and whose fixed part is connected, mechanically and electrically, to a first end, in a radially outer position, of a second section of connecting cable, held substantially radially on this link member. This overhead hook of the connecting cable has a rounded cross section, possibly an armoured structure, and is connected to the second connector, which is itself connected to the electrical equipment, for example de-icing or anti-icing equipment of this blade, and when an actuator housed in the corresponding link member commands the pivoting of the mount with the blade about the folding spindle, this first section of cable rotates with the rotating part of the rotating connector about this same spindle, at the same time as the blade, which makes any intervention on the second connector useless.
However, during the foldings of the blade, the pivoting of the blade with the mount with respect to the corresponding link member can introduce tensions that can cause damage in the overhead hook and on the rotating part of the rotating connector and also on the second connector, and such a rotating connector is furthermore a relatively complex, costly and fragile component.
In fact, it is not recommended to give this overhead hook a length sufficient to allow the complete folding of the blade whilst guaranteeing the absence of tensions, because an overhead hook of such length would have large forces applied to it and would be subjected to ample flutter movements, favouring its catching on or an unwanted collision with adjacent components, such as blade root pendular anti-vibration devices, aerodynamic dome, sleeve or drag dampers, on a rotor in rotation, on which the corresponding blade carries out angular deflections in pitch, flapping and drag.
FR 2 781 198 proposes improvements to rotors with automatically foldable blades and an electrical de-icing installation according to EP 0 754 623, in particular for avoiding the use of rotating connectors and reducing the stresses and/or displacements of the connecting cable in its overhead hook section connecting the link member to the second connector on the blade, when the rotor is rotating and during the operations of folding and unfolding the blades.
For this purpose, according to FR 2 781 198 (see FIGS. 3 and 4), an elongated part of this overhead hook, of substantially flattened rectangular cross section, whose biggest dimension is oriented substantially parallel with the axis of rotation of the rotor, is held in a member, mounted in a fixed manner or pivoting about the folding spindle, in the substantially axial projection of this folding spindle, and arranged as a fork in which the said elongated part of flattened cross section is engaged and held by at least one elastic tab. This retaining fork prevents the displacements of the overhead hook on either side of the folding spindle, during a blade""s folding or unfolding, which prevents torsions harmful to this section of connecting cable, and is much more simple, economical and reliable than a rotating connector.
But the flattened rectangular cross section of this overhead hook section of cable above the link between the blade root and the link member favours a longitudinal slipping of the section of cable in the fork during the folding of the blade, and in particular generates a large aerodynamic drag, which causes a disturbing slipstream phenomenon. Furthermore, considering the angular movements, in particular of flapping and pitch combined, of this section of cable and of its mechanical link with the link member, when that latter and the blade are carrying out these angular movements, it has proved necessary to form recesses in the periphery of a profiled dome covering the rotor head, and this amplifies the said slipstream phenomenon.
The basic problem for the invention is to overcome these disadvantages whilst avoiding the use of rotating connectors, and avoiding the formation of a disturbing slipstream, caused by recesses in the profiled dome surmounting the rotor head and by a section of connecting cable with a flat profile oriented substantially parallel with the axis of the rotor.
For this purpose, the rotary-wing aircraft rotor according to the invention, of the type described above, is characterized in that the connecting cable comprises a first flexible section, of essentially cylindrical shape with a rounded cross section, preferably substantially circular, connecting the said second connector to a second section, held on the corresponding link member, of the said connecting cable, whose first section comprises a held part which, in all the positions of the blade about the folding spindle, is maintained fixed on a cable support tied to the said folding spindle, such that the said held part is maintained above the said mount and the said radially outer end of the said link member, in an off-centered position with respect to the said folding spindle and substantially on the folding side of the said blade, in order that the folding of the blade by pivoting about the said folding spindle causes the first section of cable to curve and to move naturally in order to accommodate itself to the said folding without extension of the said first section of cable.
The rounded shape of the cross section of the first section of cable sets up only a limited aerodynamic drag and allows, at the level of the connection with the second section of cable, a fixing much closer to the link member, such that it is no longer necessary to form recesses in a protective dome of the rotor head, or at the very least the dimensions of these recesses are limited to the minimum. Furthermore, no matter on which side of the helicopter the folding of a blade is carried out, the first section of connecting cable is held, in all blade configurations, by its part held on a point of the cable support which is not in the projection of the folding spindle, but offset with respect to the latter on the folding side, such that during the folding and unfolding of the blade the first section of cable can deform naturally without extension, and in particular can curve and move in such a way as to accompany the blade during its rotation without applying damaging tension to the second connector or to the rest of the connecting cable.
According to an advantageous, simple, economical and easily removable arrangement, the held part of the said first section of cable is held in a cradle, formed in the said cable support, by at least one collar fixed to at least one side of the cradle and brought down in the closed position onto the opposite side of the cradle, to which the collar is fixed, preferably in a detachable manner, by at least one fixing element in a position of maintaining the said held part between the cradle and the collar.
Advantageously, the cable support comprises a support arm, tied to the said folding spindle, and extending in a substantially radially protruding manner with respect to the said folding spindle and on the folding side of the said blade.
This support arm can be mounted in a fixed or pivoting manner on the folding spindle and, for this purpose, the cable support advantageously also comprises a support spindle, upon which the support arm is mounted in cantilever manner and which is itself mounted substantially coaxially at the end of the folding spindle, and held in a substantially axial direction with respect to the latter, by at least one holding member.
As a variant, at least the support arm is integrated with the first section of cable, at the level of the held part, and protruding laterally from this first section of cable, and the support arm is tied to the folding spindle, for example by the intermediary of the support spindle on which the support arm is mounted in cantilever manner.
When the automatic folding apparatus of each blade is such that at least the upper end of the folding spindle is tubular, as known from FR 2 742 726, it is then advantageous for the support spindle to be partly engaged axially and held, at least axially, inside the upper tubular end of the folding spindle.
In order to reduce the bulk of the cradle and of the collar, the cradle is preferably formed in the lower face of the said support arm, and the collar is disposed between the upper face of the radially outer end of the said link member and the said lower face of the said support arm against which the said collar is fixed.
Furthermore, the held part of the first section of cable can be advantageously delimited by at least one radial excess thickness of the said first section, preferably formed by over-moulding its outer cover, and preventing longitudinal sliding of the said held part with respect to the cradle and the collar.
Also advantageously, as known from EP 0 754 623 and FR 2 781 198, and for the reasons given in these two documents, the second section of cable has an elongated part of substantially flattened rectangular cross section, maintained substantially flat on the top of the said link member, that is to say such that the largest dimension of its cross section is oriented substantially perpendicular to the axis of the rotor, in particular in order to facilitate the fixing of this second section of cable on the link member, to reduce the aerodynamic drag and to attenuate the mechanical forces applied to this section of cable, which preferably furthermore extends in a direction laterally inclined with respect to the longitudinal axis of the said link member, on the folding side of the blade, in order to facilitate the connection of the first section of cable, to limit the length of the latter and to make its installation more favourable between the link member and the second connector.
Thus, the rotor according to the invention can also benefit from the advantages resulting from the use of other features of the electrical connection installation according to EP 0 754 623 and FR 2 781 198, to which reference can be made for more details, and whose descriptions are incorporated in the present description by way of reference.
In particular, the second section of cable can be advantageously connected to the first connector on the hub by the intermediary of a third section of the connecting cable, the said third section comprising an overhead hook, in the shape of a flattened half-loop, of substantially flattened rectangular cross section whose largest dimension is substantially perpendicular to the axis of rotation, and whose concavity is facing substantially towards holding and articulation means connecting the corresponding link member to the hub, and substantially radially towards the axis of rotation, the said overhead hook being thus deformable in flexion and torsion in order to accommodate itself to the angular deflections in pitch, drag and flapping of the blade and of its link member with respect to the hub, as known from the two documents mentioned above.
Similarly, the second section of cable can advantageously be connected to the overhead hook of the third section of cable by a joint connected to the link member by a link which is articulated at least in pivoting manner about an axis substantially parallel with or slightly inclined with respect to the longitudinal pitch change axis of the link member and of the blade, in order to attenuate the mechanical forces applied to the connecting cable whilst allowing a good take-up of the forces applied to the latter when the rotor rotates and the corresponding blade is carrying out its angular deflections in pitch, flapping and drag, as proposed in FR 2 781 198.

Rotary-wing aircraft rotors with automatically folding blades and electrical connection installation for the blades


A coordinate transformation method and apparatus that uses a lookup table to store a sample of transformed output values and an interpolator for interpolating between samples of the output values to provide an output data value. The samples are stored at varying sample spacings to accommodate varying curvatures of the transformation function so as to minimize interpolation errors.

In color image processing it is often required to transform color image signals from one color space such as R,G,B to another such as C,M,Y,K. This transformation is frequently performed by employing three or four dimensional lookup tables to transform electronic image data representing color images from one color space to another, and also to transform color data from an input device into a desired color representation for an output device. These tables consist of sparsely spaced data points regularly populating the three or four dimensional input color space and the output data is derived generally by performing a linear interpolation or signal dependent matrix operations on neighboring values over regularly defined regions within the input space. See for example U.S. Pat. No. 4,275,413, entitled "Linear Interpolation for Color Correction," issued Jun. 23, 1981 to Sakamoto, et al.; U.S. Pat. No. 4,511,989, "Linear Interpolating Method and Color Conversion Apparatus Using This Method," issued Apr. 16, 1985 to Sakamoto; and U.S. Pat. No. 4,346,402 "Image Reproduction Apparatus": issued Aug. 24, 1982 to Pugsley. Generally speaking, these regions in the input color space are defined by a list of points within a lookup table arranged in a manner to facilitate retrieval. As shown in FIG. 2, these points are samples on a three or four dimensional grid. FIG. 2 shows an example of the division of a three dimensional volume where the coordinate axis are labeled A, B and C and may represent for example R, G, B color components. This construction is, however, non-optimal because when a linear or matrix approximation technique is used for interpolation, error is introduced by the straight line approximation of the interpolation technique. The magnitude of the error is related to the local curvature on a slope of the transformation function. This error can become extreme near a color gamut boundary, in certain regions of the color space depending on the specific color transformation.
To illustrate the problem, a function f(x) is shown in FIG. 4, having a high rate of curvature between the samples at n and n+1. The interpolated value f(x) between n and n+1 contains a large error, whereas the interpolated values f(x.sub.o) and f(x.sub.2) do not.
FIG. 3 is a schematic diagram illustrating this prior art technique for performing transformations on data. As shown in FIG. 3, lookup table 10 contains a regular sample of transformed data values f(x), The lookup table 10 and associated control logic is arranged to output a plurality of neighboring transformed values f(n) and f(n+1) where x is between n and n+1, in response to the high order bits of an input data value x. The transformed values f(n) and f(n+1) are supplied to an interpolator 12, along with the low order bits of the input data value. The interpolator 12 employs the low order bits as an interpolation factor F to interpolate a value f(x) between f(n) and f(n+1). Although the example in FIG. 3 is shown as a one dimensional interpolator for ease of description, the concept is readily extended to higher dimensions such as three dimensions for color image signals.
In an attempt to further reduce the size of the lookup table 10, for multidimensional data, such as color image data, it is known to perform a further transformation on each color component of the input image data prior to performing the color transformation to reduce the number of bits in the component data values. See U.S. Pat. No. 4,346,402 issued Aug. 24, 1982 to P. C. Pugsley. Also, for color image signals, special three dimensional interpolation algorithms have been proposed for increasing the efficiency of the interpolator 12. See for example U.S. Pat. No. 4,275,413 issued to Sakamoto et al., Jun. 23, 1981; U.S. Pat. No. 4,477,833 issued Oct. 16, 1984 to Clark et al,; and U.S. Pat. No. 4,511,989 issued Apr. 16, 1985 to Sakamoto.
All of these prior art approaches suffer from the shortcoming that in regions where the multi-dimensional transformation function exhibits a high curvature, the interpolation results in greater error. If this problem is remedied simply by sampling the output values at a higher frequency to reduce the error, the size of the lookup table memory holding the sample of output values is greatly increased, and therefore becomes prohibitively costly.

Apparatus and method for performing coordinate transformation employing stored values and interpolation


Describes a device which embodies a method of providing a periodic test light-source beam directed at a nephelometric turbidimeter's scattered-light detector window to detect any film build-up on the scattered-light detector's optical surfaces by means of a change in reading from a previous reading.

Current detection of film build-up on optical windows in nephelometric turbidimeters is primarily by visual inspection. The particulate response of the turbidity measurement provides a possible clue that build-up and fouling of the optical surfaces may be a cause of the change in unexpectedly low readings of the turbidity response. Attenuation of light caused by fouling of optical surfaces is reflected in lower readings than expected for the actual turbidity concentration.
The USEPA is in the process of changing their procedures to incorporate newer technology around the use of LED and laser light sources, with reference to this inventor's U.S. Pat. No. 7,659,980 B1. These stated light sources are more stable in their output than the older incandescent light sources with their drifting filaments. Associated electronics have also advanced in recent years in the capability to control source light stability through better feedback circuitry.
In order to complete these changes in the EPA procedures and specifications, the EPA recommended that detection for specific film build-up on optical surfaces be a part of the new procedure specifications required for nephelometric turbidity measurement used in water and waste water treatment plants. The patents and accompanying EPA Mitchell Methods M5331 and M5271 addressed drifting in the instruments cited in the Methods and patent above.
Under the older U.S. specifications, primarily using incandescent light sources, plant operators found that only after cleaning of the optical surfaces was a more accurate determination of the measurement response possible. In most incandescent instruments, visual inspection of the optical surfaces requires a breakdown of the instrument in order to determine if build-up has occurred.
Elimination of film build-up on optical windows by plant operators may include: automatic wipers, ultrasonic vibration, air or water jets, and/or disassembly of the unit so that windows can be wiped or cleaned manually. Unfortunately, each of these methods is incomplete in fully removing film build-up, giving a false interpretation of the window's actual cleanliness. In addition these intrusive methods allow unintended changes in the water condition, which then affects an accurate response reading. The object of the present device is to assist the operator in making a better decision about the accuracy of turbidity responses in regards to the attenuation of its light source due to fouling on optical surface(s).
Below is a comparison between the instant invention with patents or patent applications which provide various additional approaches to detection of fouling on optical surfaces. None of these approaches, using scattered-light sensors, use this inventors' unique nephelometric turbidity scattered-light sensor design.
There are a number of prior-art patents suggesting ways to detect fouling in instrumentation in fluid/liquid conditions. U.S. Pat. No. 6,023,070 describes use of a plastic conduit measuring absorbance of the light beam. Control of the beam intensity, detector sensitivity and associated electronics were not included. Two areas of the tube, one fouled and one un-fouled, was measured and compared by the device. This method is not appropriate for use with this inventor's fouling detection device, which is to be used in conjunction with the cited Mitchell patent covering the inventor's nephelometric turbidimeter, functioning in the absorption mode, in which all areas are fouled.
U.S. Patent Application 2002/0108911A1 measures fouling by having two sensors in the fluid; one that has been allowed to foul and a second one that has been cleaned—then measured and compared after re-immersion in the fluid. There is no mention in this patent control of the beam intensity, detector sensitivity and associated electronics. This method is not appropriate for use with this inventor's fouling detection device, which is to be used in conjunction with the cited Mitchell patent covering the inventor's nephelometric turbidimeter, functioning in the absorption mode, in which all areas are fouled.
Another approach found in U.S. Pat. No. 5,185,333 describes a method of measuring fouling by using two sensors; one allowed to foul and the other periodically cleaned. The light transmitted from one side of the container is compared to the opposite side. Again, there is no mention of control of the beam intensity, detector sensitivity and associated electronics. This method is not appropriate for use with this inventor's fouling detection device, which is to be used in conjunction with the cited Mitchell patent covering the inventor's nephelometric turbidimeter, functioning in the absorption mode, in which all areas are fouled.
U.S. Pat. No. 4,896,047 describes a method of measuring gas-stack fouling by successive cleaning and measuring the absorbance of a light beam across the stack and checking for changes. There is no mention of control of the beam intensity, detector sensitivity and associated electronics. This method is not appropriate for use in water or liquid with this inventor's fouling detection device, which is to be used in conjunction with the cited Mitchell patent covering the inventor's nephelometric turbidimeter, functioning in the absorption mode, in which all areas are fouled.
An additional approach in U.S. Patent Application 2013/0003048A1 describes a method similar to the present device but with restrictions which substantially differ:
Claim 14 describes an optical method for measuring the optical transparency of the fluid in a fluid treating device as a means of measuring fouling of surfaces in contact with the fluid. The device measures the transparency of the fluid at two locations, one fouled and one un-fouled. This method is not appropriate for use with this inventor's fouling detection device, which is to be used in conjunction with the cited Mitchell patent covering the inventor's nephelometric turbidimeter, functioning in the absorption mode, in which all areas are fouled.
Claim 17 describes use of a light source for measuring the optical transparency described in claim 14 by use of a light source, transparent window, said fluid, and an optical detector, which is immediately adjacent to the light source window, to detect light scattered by the fouling on the transparent window. This method is not appropriate for use with this inventor's fouling detection device which is to be used in conjunction with the cited Mitchell patent covering the inventor's nephelometric turbidimeter, functioning in the absorption mode, as it would be mechanically and optically impossible to position the measurement device in the stated adjacent position.
Claim 19 describes: (a) Measures the transparency of the fluid for changes in transparency which indicates a change in the fouling of the surfaces. Without control of changes in the light source, changes in the detector and its electronics, which are not mentioned, this approach would not be appropriate for use with this inventor's fouling detection device which is to be used in conjunction with the cited Mitchell patent covering the inventor's nephelometric turbidimeter functioning in the absorption mode.
(b) claim 19 describes use of an equation in the determination of the fouling parameter. A mathematical equation would not be appropriate for incorporation of the present device in this inventor's fouling detection device, which is to be used in conjunction with the cited Mitchell patent covering the inventor's nephelometric turbidimeter, as its device detector, under electronic control, is also the nephelometric turbidity detector, but functioning in the absorption mode.
(c) Measurement within a fouled location compared with measurement of an unaffected location quantifies the level of fouling in Claim 19. Use in this inventor's fouling detection device, which is to be used in conjunction with the cited Mitchell patent covering the inventor's nephelometric turbidimeter, functioning in the absorption mode, would be inappropriate as fouling in this instant device is displayed only in reference to a previous reading and is not quantified by the level of fouling. Claim 19 describes the level of fouling, while this instant invention describes any change in fouling from the last time it was checked.
There are additional factors potentially affecting the response reading. Three of these are stated below to clarify that they have been eliminated or were not factors which needed to be overly considered. Items 1 and 2 were covered in the above cross-referenced sensor design. Item 3 is negligible due to the EPA ruling for variance:
Light Source Attenuation Factors Which Were Previously Resolved in the Cross-Referenced Design and/or Patent, or by the EPA Ruling of Variance:
1. Variation in the source light of the cross-referenced sensor device is controlled by electronic feedback circuitry, removing this as a factor.
2. Changes in sensitivity of the scattered-light detector and its associated electronics were eliminated by use of the Mitchell Self-Check circuit described in the above cross-referenced U.S. patent, removing this as a factor.
3. Attenuation of the light beam passing through particulate matter in the liquid lowers the response reading. Common usage references indicate that a 100 NTU (Nephelometric Turbidity Units) liquid of particulate density through a 10 cm path length has a light loss of 10%. The cross-referenced sensor device was designed with a path length of 4 cm, (EPA specifications limit nephelometric turbidity Methods to 40 NTU) therefore a change in light loss of 1.6% is negligible. The EPA allows a 10% variance, removing this as a factor.
The Two Elements of Focus for the Present Device:                Fouling of the test source-light window, which essentially cannot be eliminated, but acts as a surrogate detection for fouling of the operating source-light window;        Fouling of the scattered-light detector window.
USEPA Guidance Manual for Compliance with the Interim Enhanced Water Treatment Rule: Turbidity Provisions, state: "If the instrument has internal electronic diagnostics, designed to assist in determining proper calibration, the operator should use these tools to verify proper calibration operation." The rules continue to state that "the unit should be thoroughly cleaned."
Determination of fouling of optical windows and fouling elimination falls under this directive. Unfortunately, there is no current system designed to determine fouling on optical windows accept as described above. It is the object of this present device to provide a means of determination of fouling, internal to the nephelometric turbidity system, without disassembling the unit manually for visual inspection.
Internal detection of fouling can be automatic or placed on a periodic schedule by the operator. It has been shown that keeping windows clean is more efficient and effective than cleaning a window after it has become fouled. The object of this present device is to provide a means of determining fouling, or absence of fouling, on a periodic basis, or as needed when the water condition changes. The water plant operator has this data at his disposal 24/7, to a degree far more effective than visual inspection can provide.
Cross-Referenced Patent with the Present Device: Application and use of the present device is to be used in conjunction with the Nephelometric Turbidity Sensor Device referenced in U.S. Pat. No. 7,659,980 B1. The purpose of this present device is to assist the plant operator in determining if the accuracy of the turbidimeter response reading is being affected by fouling on the optical window(s) either by organic or non-organic processes, without increasing contamination of the water condition through manual inspection.

Device for the detector of fouling on optical surfaces of a nephelometric turbidimeter submerged in a liquid


A locking tool includes a handle and an elongated tool blade having a body and a tang. The tool blade has a tang spline opening formed therein which defines an annular array of alternate spline teeth and splined slots. A transversely-extending lock member has a spline ring with an annular array of alternate spline ribs and spline grooves formed thereon complementary to the tang spline opening, and is translatable between a locked position and a released position. The tool blade is attached to the handle by the locking member such that when the lock member is in the released position, the tool blade is freely pivotable about the locking member. When the lock member is in the locked position, the spline ring engages the tang spline opening such that the tool blade is retained in one of a plurality of predetermined angular positions relative to the handle.

This invention relates generally to a folding tool, and more particularly to a folding knife which locks in multiple positions.
Folding tools, particularly including knifes and other cutting implements, are well known. A folding knife typically includes a blade which is pivotally mounted to a handle so that it can swing between an open position and a closed position in which the cutting edge is covered by the handle to protect both the user from injury and the blade from damage. It is also known to provide such knives with a lock to prevent inadvertent closing of the blade during use. However, such locks fail to provide both multiple positions and easy release of the blade.
Accordingly, there is a need for a folding tool which can be securely locked into a plurality of positions.


A system including a switching device for switching an auxiliary display unit between a first state, corresponding to nominal operation, for which a screen of said auxiliary display unit is controlled by a control assembly of a main display unit, and a second, standby state, corresponding to a situation in which the main display unit has broken down, for which state said screen is controlled by a control assembly of said auxiliary display unit.

The present invention relates to a display system for the cockpit of an aircraft, in particular of a transport airplane.
It is known that, on airplanes, the data used in particular for flying, steering and navigation are presented to the crew primarily by means of two display systems: a control and display system (CDS) for nominal use and a standby navigation system (SNS) for emergencies, as set out below. For safety reasons, these two systems are independent from one another and different.
Conventionally, a CDS system is formed of different display units and supplies various data, in particular:                primary flight data (altitude, attitude, speed, etc.);        a (horizontal and vertical) navigation chart;        engine parameters;        the status of the aircraft;        the status of systems and dedicated warnings; and        various pages for determining and altering the flight plan, in order to manage communications with air traffic control and for supervisory purposes.
In recent versions, some of the formats displayed by a CDS system have been interactive.
Moreover, there are attempts to integrate more and more functions into CDS formats, in relation to, for example:                navigation at an airport;        maintenance functions;        systems control;        communications via data transmission, etc.
This has resulted in a significant increase in the total display surface area of the CDS system. At the same time, the size of each individual display unit of the CDS system is also increasing to allow the use of larger formats, such as airport maps. This has led to increases in the number of display units and the total display surface area.
Moreover, the SNS system can be used in particular (but not exclusively, as set out below) as a standby system in the event of a CDS system outage. The SNS system generally comprises:                a pitot probe and a static probe; and        one or more standby display units of the ISIS (or "integrated standby instrument system") type, comprising a small display surface and inertial sensors (accelerometers and gyrometers).
FR-2 784 457 relates to an ISIS standby display unit which displays piloting information (altitude, speed and attitude) for the aircraft on a screen.
The SNS system is formed so as to provide the functions which are essential for the crew to fly and steer the aircraft safely, until completion of the flight under way. The data displayed by an SNS system generally comprise:                air data and inertial reference (altitude, air speed, attitude, etc.) parameters; and        navigation information (crossings, etc.).
While the current display solution based on the CDS and SNS systems are entirely satisfactory on existing aircraft, said systems might show some limitations for future aircraft, in particular for the following reasons.
The operational perimeter of the CDS system increases from one program to the next, supplying the crew with more information and doing so in a smarter manner: the data are thus filtered, processed and presented visually, so as to be easily interpretable by the crew, and this only when necessary.
As regards the operational perimeter of the SNS system, this remains stable. Thus, from an operational perspective, there is a widening difference between the CDS and SNS systems. For the crew, it may become more complicated in the future to manage the transition over to the SNS system after the outage of the CDS system. Indeed, even if future CDS systems make it possible to limit the training of the crew in many situations owing to an intuitive interface and new functions, the crucial aspect of a pilot's training will concern flying the aircraft using the basic SNS system. The SNS system is, therefore, a curb on the evolution of pilot training.
A simple solution would be to increase the operational perimeter of the SNS system. However, this is not possible without increasing the surface area allotted to said SNS system within the cockpit. Yet, space is already limited within the cockpit, and the SNS system needs to located within the pilots' visual field and correctly oriented. Moreover, it needs to be easy to transition between the SNS and CDS systems. The only possible arrangement which meets these requirements would be on the instrument panel. However, the entire instrument panel is already taken up by CDS systems and installing thereon a standby system which will not generally be used is not necessarily a satisfactory solution.


In accordance with embodiments of the present disclosure, an information handling system may include a user interface comprising an interface device, one or more sensors, each respective sensor configured to detect a respective parameter indicative of human proximity to the interface device, and a processor communicatively coupled to the user interface and the one or more sensors. The processor may be configured to in response to a physical interaction with the interface device, read information from the one or more sensors, determine whether the information from the one or more sensors satisfies a condition indicative of human proximity to the interface device, and process the physical interaction with the interface device based on whether the condition is satisfied.

As the value and use of information continues to increase, individuals and businesses seek additional ways to process and store information. One option available to users is information handling systems. An information handling system generally processes, compiles, stores, and/or communicates information or data for business, personal, or other purposes thereby allowing users to take advantage of the value of the information. Because technology and information handling needs and requirements vary between different users or applications, information handling systems may also vary regarding what information is handled, how the information is handled, how much information is processed, stored, or communicated, and how quickly and efficiently the information may be processed, stored, or communicated. The variations in information handling systems allow for information handling systems to be general or configured for a specific user or specific use such as financial transaction processing, airline reservations, enterprise data storage, or global communications. In addition, information handling systems may include a variety of hardware and software components that may be configured to process, store, and communicate information and may include one or more computer systems, data storage systems, and networking systems.
An information handling system may include push buttons or other interface devices to allow a user to interact with the information handling system. A non-limiting example of such a push button is a power button which a user may press in order to power on or power off the information handling system, wake the information handling system from a reduced power state, and/or other functionality. In some instances, certain interactions with a power button may cause performance of other functionality besides power operations. For example, in some instances, in response to a user pressing and holding a power button for more than a minimum amount of time (and, in some instances, less than a maximum amount of time), an information handing system may be configured to delete all or a portion of a memory of the information handling system.
However, such a power button may be susceptible to being pressed accidentally by an object other than a person. For example, in an information handling system packed in a book bag, a power button may be unintentionally pressed and released as the book bag is repeatedly picked up and placed down on the ground or other surface while a user thereof is waiting in a line. As another example, in an information handling system packed in an item of overstuffed luggage and placed in a vehicle, a power button may be unintentionally pressed and released as the vehicle drives over bumps of a road upon which the vehicle drives. As a further example, students may, at the end of a day of instruction, individually load information handling systems into a cart, and while doing so, accidentally cause a power button to be unintentionally pressed and released. Such unintentional physical interaction with a button may cause undesirable power cycling of the information handling system, accidental erasure of memory of the information handling system, and/or other deleterious effects.

Systems and methods for processing of physical interaction with interface device of information handling system based on sensor information indicative of human proximity


A system and method for dewatering particulate materials employs an improved dewatering probe generally including a single non-conducting pipe having a plurality of holes or slots, an anode mounted on the pipe adjacent one end of the pipe, and a cathode mounted on the pipe adjacent the opposite end of the pipe. The pipe serves as both a sonde for mounting the anode and cathode and as a well for extracting water that collects around the outside of the pipe and flows into the interior of the pipe through the holes or slots via gravitational and electro-osmotic forces. A pump may be used to extract both collected water and accumulated electrolytic gases from the pipe's interior. In embodiments, an array of guide electrodes is mounted on the pipe in addition to the anode and the cathode in order to deflect the major current flow out into the body of surrounding particulate materials. The guide electrodes also facilitate rapid depolarization of the probe. An array of probes according to the present invention may be employed as a system to dewater a volume of particulate.

1. Field of the Invention
The present invention relates generally to dewatering devices, and, more particularly, to an improved active and electro-osmotic dewatering system.
2. Background Description
Many common building and insulating materials have a capillary pore system that can become saturated with water. This is especially the case where the material, such as a building's foundation, is in contact with a particulate moisture source, such as soil. Long-term continuation of this saturated condition is undesirable and may lead to deterioration of the materials. Similarly, sludges, dredged spoils, and fine aggregates can become laden with moisture, making them unstable to stockpile and heavy to transport or dispose.
One traditional procedure for dewatering particulate materials is a combination of heating and ventilation. However, these procedures are very slow and utilize large amounts of energy. Further, as with any process utilizing heat, there is a risk of thermally induced warping and cracking of the structure.
Accumulated water may also be pumped from the particulate material. However, employing this method on any significant volume of particulate requires either a substantial number of pumps or a great deal of suction, as capillary forces in fine-grained materials make it difficult to extract water. Additionally, a simple pumping system is relatively easy to overwhelm with wet weather.
Another known technique for eliminating water from porous or particulate materials is electro-osmosis. The walls of the capillaries in most common building materials are covered with an electrically charged, adsorbed water film, referred to as an electrical double layer. It has been established that, if such a porous body is subjected to an electrical field, part of the double layer will tend to migrate under the influence of the field. Some of the free liquid in the pores is carried along with the double layer, leading to a significant reduction in the moisture content of the porous body or particulate.
There are, however, practical drawbacks to the use of electro-osmotic dewatering systems. First, conventional electro-osmotic systems are rather inefficient, and therefore relatively easily defeated by wet weather. The application of an electrical charge to a wall of porous building material typically involves the use of electrodes provided or installed in the porous material, and connected through the material to a grounding electrode. When the electrodes are polarized, there is a migration of water molecules towards the cathode. However, after the system has been in operation for a time, the electrodes become covered with coherent films of gas formed by electrochemical reactions at the electrode surfaces. These films have a very high electrical resistance, leading to deterioration in the electrical characteristics of the system and lowered system efficiency. A similar problem arises from the fact that the anodes of the system are subject to a high degree of electrolytic corrosion. Where electrodes are installed specifically for dewatering, this corrosion results initially in reduced system efficiency, and, eventually, in complete electrical discontinuity at the electrode. Thus, it becomes necessary to discontinue use of the system or replace the electrodes. Alternatively, where the structure's internal reinforcing steel is used as the anode, heavy corrosion of the electrode is damaging to the structure itself.
Accumulated gases present another problem in existing electro-osmotic dewatering systems. As noted above, any passage of current through water will result in some electrolysis of the water. This can generate hydrogen, oxygen, and chlorine gases that can accumulate in an empty extraction casing. These accumulated gases may also react, producing an undesirable energetic event, such as a fire or explosion.
Extant electro-osmotic dewatering systems also require a great deal of space to install. A typical electro-osmotic dewatering system, such as that taught by U.S. Pat. No. 6,372,109 to Bjerke et al., employs horizontally arranged electrodes and a surface array. These horizontally disposed systems generally use a separate steel casing as an anode and collect water at a cathode/extraction pipe situated away from the area to be dewatered—that is, at least two probes are required to accomplish the dewatering.
Prior art dewatering systems are also subject to encrustation in the extraction pipe. Where the metal is a cathode, the pH at the surface of the pipe rises, allowing precipitation of minerals from the groundwater. This precipitate can obstruct or clog the slots or perforations in the extraction pipe.
Electrical isolation is also a problem with existing electro-osmotic dewatering systems. If the surrounding soil is dewatered to such an extent that the resistance around the metal pipe increases, the dewatering circuit is effectively broken. Anyone touching the metal pipe, or even an extraction pump attached to the system, is a better conductor to ground than the metal pipe, making extant systems rather dangerous, especially for systems that run at high voltages.

Method and system for dewatering particulate materials

The United States of America as represented by the Secretary of the Army


A retrieval system for a duck decoy. The retrieval system comprises a bi-directional motor having an output shaft, a housing and a T-shaped member disposed within the housing and attached to the output shaft. The rotation of the motor causes the T-shaped member to engage a post on the reel causing the reel to rotate in the same direction as the motor and T-shaped member. In this manner, the retrieval system is capable of winding the decoy cord to raise the anchor of the duck decoy. The speed of rotation of the T-shaped member can be controlled by the user.

1. Field of the Invention
The invention relates in general to duck decoys, and in particular to a retrieval system that allows the hunter to automatically wind the decoy cord to raise an anchor on a duck decoy.
2. Related Art
In the popular sport of duck hunting, the use of duck decoys is quite common. Oftentimes, numerous duck decoys are deployed by the hunters, sometimes as many as a hundred decoys may be set up by the hunters. In most circumstances, the hunters must set out and retrieve their decoys each day they hunt. It is also possible that while hunting the hunters may want to relocate their decoys due to changing weather conditions or to a location of more desirable duck activity.
Typically, each duck decoy is held in place using an anchor attached to a cord on a reel located underneath the decoy. The reel usually has a winding mechanism that allows the hunter to manually wind the anchor. Because of the number of duck decoys that are deployed by the hunter, the task to wind the anchor becomes very tedious and time-consuming.
Many conventional devices are known in the art that automatically wind the reel of the duck decoy. However, these conventional devices are unreliable because of their complex design, making them unduly complicated.


The invention provides a system for analysing a signal received over a channel to determine the channel characteristics. The determined characteristics are then used to divide the sub-carriers up into groups with similar fading characteristics and allocating a pilot channel to each group. The determined pilot allocation scheme is then used for future transmissions across the channel.

There are now a number of systems which operate at high data rates such as multimedia applications like Wireless Local Area Network (WLAN); Wireless Personal Area Network (WPAN), e.g. Bluetooth; etc. Various arrangements have been proposed in order to facilitate such high data rates in a reliable and practical way. However, there are a number of problems associated with high data rate wireless channels, particularly due to multipath. This is especially problematic indoors where the environment is particularly dispersive due to the large number of objects and surfaces as well as the dynamic nature of structures, particularly people, moving about. Consequently, it can be extremely difficult to extract and retrieve the original information from a transmitted signal reliably and without extremely complex processing. This results in complex receivers which must be capable of estimating and compensating for the multiple versions of the original signal arriving at the receiver due to the different path length of each version.
In order to counter this, a multi-carrier approach has been proposed in which the original data stream is separated into a series of parallel data streams, each of which is modulated and transmitted with a different frequency, generally within the same band. This allows the relative size of the transmitted symbols relative to the multipath delay to be much larger and so inter symbol interference is reduced. One particularly advantageous system, which utilises multiple carriers is Orthogonal Frequency Division Multiplexing (OFDM).
OFDM is very effective at overcoming the problems of fading and multipath. This is achieved by dividing a frequency selective fading channel (i.e. a channel where the fading characteristics at one frequency are likely to be different to those at neighbouring frequencies such that the profile of the received signal against frequency is not flat) into a number of flat fading sub-bands. In this way, the profile within the sub-bands is approximately flat. These sub-bands relate to the OFDM sub-carrier frequencies.
FIG. 1 shows an example of the layout of a transmitter 10 and receiver 20 for an OFDM system. In the multi-antenna receiving unit 21, each of the antennas receives a signal, which is fed to an analogue to digital converter 22 and then into a serial to parallel converter 23 to separate the individual sub-channels. The sub channels are then processed through a Fast Fourier Transform (FFT) 24. Finally, the signals are converted from a plurality of parallel signals into a serial signal for each sub-channel and the coded data extracted.
In such an OFDM receiver system, it is possible to apply adaptive beamforming weights at various points in a receiver as shown in FIG. 1. However, the effectiveness of these weightings will largely depend on the stability and coherency of the propagation channel. If the channel undergoes flat fading (i.e. the signal strength of each of the sub-carriers is affected to the same extent), then it can be regarded as being a narrowband channel. In this case, a single set of weights can be applied at radio frequency (RF) or intermediate frequency (IF), to the received signal just after the antenna array 21, i.e. at position (1) in FIG. 1. Alternatively, the weights may be applied after the analogue to digital unit 22 at position (2) in FIG. 1. Both of these positions should be sufficient for optimum spatial processing.
However, in wideband systems, operating at high data rates such as WLAN, WPAN, etc., where bandwidths of 10 MHz or higher may be required and/or systems operating in highly dispersive environments, signals will occupy a spectrum in excess of the coherence bandwidth. Consequently, there will be significant variation in the quality/signal strength of the channels across the bandwidth. Consequently, it is unlikely that a single set of weights (i.e. as in narrowband beamforming) would be satisfactory for beamforming.
One way to overcome this problem is to process the received data and apply weightings in the receiver for each sub-carrier, after the FFT 24, i.e. at position (3). FIG. 2 shows an example of a receiver. In this system, the signal is received by antennas 101,102,103. Pre-processing units 104,105,106, carry out downconversion, A to D conversion, serial to parallel conversion and FFT processing. The outputs are then fed into an array of adaptive signal processing devices 107,108,109 which include a plurality of multipliers 110 which multiply each of the received signals by a weighting value w determined by a weight determining unit 113. Each of the weighted signals from the multipliers is then summed 111 to provide an output signal. The output signals from each of the weighting units is then fed to a combining unit 112 which extracts a data signal in which the delayed signals and interference signals have been removed from the received signal.
However, in the example shown, the receiver has L antennas and the number of sub-channels that each antenna receives is N. Therefore, the total number of weighting units required is L×N. This can lead to a very large number of multipliers 110 being required. For example, in the HIPERLAN system, there are 48 data sub-carriers and 4 pilot sub-carriers (N=52); there is also a DC channel (CH0) which does not carry data. This means that the receiver is complicated and this results in the receiver being expensive and potentially subject to reliability problems. In addition, the weighting is normally implemented in software and so processor demand is extremely high, again resulting in high expense or poor performance. If the processing to determine the weighting to be applied is unduly complex, then it may take a significant amount of time to complete. During this time, the channel parameters may have changed significantly and so the calculated weightings could be inappropriate. Under these circumstances, the weighting produced would always out of date and hence poor performance will result where the characteristics of the channel change rapidly with time.
One way to reduce the processor demand, is to divide the operating bandwidth into a number of sub-bands and then select one sub-carrier from within each sub-band on which to base all calculations. This method relies upon each sub-band behaving generally as a narrowband, i.e. that the sub-band effectively undergoes flat fading. In other words the chosen sub-carrier is accurately representative of the fade within the sub-band as a whole. However, without prior knowledge of the operational environment, it is difficult to know to what extent the operating band should be divided up. Where large sub-bands are chosen there is a danger that the chosen sub-carrier would not be sufficiently representative of the sub-band and performance would be degraded. In contrast, if the number of sub-bands is chosen to be large (i.e. few carriers per sub-band), whilst the representative sub-carrier is likely to be accurately representative of the sub-band, the amount of processing required is disadvantageously high.
EP-A2-0,852,407, which relates to current standards for 5 GHz WLANs, suggests reducing the total number of adaptive signal processing units and hence the number of weighting units to improve the receivers by reducing the complexity. The document describes dividing the operating band into four equal sub-bands each having a 'pilot' sub-carrier.
Providing pilot sub-carriers at equal intervals amongst the sub-carriers allows the receiver to calculate the average and differential carrier phase errors. This is achieved by knowing the form of the pilots. Using this information, the receiver can fine-tune the carrier and timing tracking circuits such that errors are minimised.
An example of this arrangement is shown in FIG. 3 where the operating band is divided into fifty-three channels or sub-carriers (i.e. as in HIPERLAN), these are then divided up into four separate groups each defining a sub-band. Each sub-band includes a sub-carrier, which acts as a pilot for the group (in the example, channels −21, −7, 7 and 21). The pilot channels do not carry signal data but contain a predetermined sequence for use in equalising the received signal by comparing the received signal to an expected signal. Weighting for the received signals is determined using the pilot sub-carriers and is then applied to each sub-carrier in the respective sub-band. As indicated above this system relies upon flat fading over each sub-band, which in the case of the above referenced document are of the order of 5 MHz in size.
To aid the coherent demodulation process for OFDM systems, pilot sub-carriers are interspersed between the data sub-carriers at equal intervals. Knowing the form of these pilots, it is possible to calculate the average and differential carrier phase errors, which can in turn be used to fine-tune the carrier and timing tracking circuits in the receiver, such that any errors are minimised.
If the bandwidth of the system is increased such that the sub-bands have considerably greater bandwidth, for example in the region of 10 MHz, then the likelihood that the sub-bands will have flat fading is considerably reduced, particularly where the environment is such as to give strong multipath interference, e.g. indoors. Consequently, the pilot is less likely to provide an accurate indicator for the sub-carriers in the sub-band.
Dynamic allocation of the modulation scheme of sub-carriers has been proposed, for example the Atheros system, to extend the basis of 5 GHz systems to allow a wide range of devices to coexist under a unified protocol. In this way, individual sub-carriers are allocated a modulation scheme according to the existing conditions. In the Atheros system, the highest order modulation scheme possible is allocated to each sub-carrier to maximise throughput. If some of the sub-carriers are experiencing more severe fading, then a lower order modulation scheme can be applied. This reduces the potential throughput but provides a more reliable transfer and so the valid data throughput is maximised.
A further problem associated with this arrangement is that if a pilot channel falls in a frequency slot that is experiencing severe fading, the pilot may be unrecoverable and cannot be used in the calculation of the average and differential carrier phase errors. Consequently, a large portion of the band may become unrecoverable due to the reduced estimation and interpolation between the remaining pilots. FIG. 4 shows an example of a dispersive channel based upon the ETSI 5 GHz HIPERLAN/2 channel models, indicating the approximate spacing and locations of pilots. Of the four pilots, one of the pilots is in a deep fade. Consequently, the receiver may not be able to recover the pilot and therefore the group of channels that rely upon the information from this pilot may also be unrecoverable. Referring back to FIG. 3, it will be apparent that the sub-carriers in group 3 would be unrecoverable due to the loss of the pilot in channel 7.
Application number GB0108026.6 describes a system for rearranging the sub-bands according to the channel characteristics. In this way, the sub-carriers can be dynamically allocated to sub-bands so that all the sub-carriers within a sub-band have similar coherency within a limited period of time.


A communication device, including: a processing unit configured to generate a first protocol data unit (PDU) including first sequence number information specifying a first sequence number of a data unit set for each multicast group, multicast group information specifying a multicast group, and a data unit; and a wireless communication unit configured to transmit the first PDU generated by the processing unit. The communication device provides a mechanism capable of improving efficiency of wireless communication even in a case in which a plurality of types of multicast communication which differ in a multicast group serving as a destination are performed.

In recent years, wireless local area networks (LANs) representative of Institute of Electrical and Electronics Engineers (IEEE) 802.11 have been widely used. In addition, the number of wireless LAN-compatible products (hereinafter, also referred to as wireless communication devices) have also increased in accordance with this. In contrast, wireless communication resources available for communication are limited. Therefore, it is desirable to increase the efficiency of communication between wireless communication devices.
As an example of a technique for improving communication efficiency, a technique of reducing a communication volume in an acknowledge is known. Specifically, there is a technique of reducing a block acknowledgment request (hereinafter also referred to as a "BAR") in communication using a BAR and a block acknowledge (hereinafter also referred to as a "BA"). For example, a technique in which a communication device that has transmitted a multicast data frame transmits a BAR frame including information specifying a communication device serving as a BA frame communication target once, and each communication device serving as the BA frame communication target transmits a BA frame for the BAR frame upon receiving the BAR frame is disclosed in Patent Literature 1. As a result, the communication volume is considered to be reduced as compared with a case in which the BAR frame is transmitted to each of the communication devices serving as the BA frame communication target, that is, a case in which a plurality of BAR frames are transmitted.
Note that a communication device that transmits a BA frame generally waits to resend a frame that has been failed to be received. According to IEEE 802.11 standards, for example, sequence numbers are managed for each traffic stream, and data with sequential sequence numbers is provided to a communication upper layer. Therefore, in a case in which a part of the sequence numbers is missing, the wireless communication device waits for resending of the frame that has data corresponding to this part of the sequence numbers until the frame is successfully received.

Communication device, communication method, and program


A lens barrel comprises an outer frame and an inner frame. The lens barrel has a first state, a second state, and a third state during operation in which the outer frame and the inner frame rotate relatively. In the first state, a first cam follower is guided by a first cam. In the second state, the first cam follower is guided by the first cam, and a second cam follower is guided by a second cam. In the third state, the second cam follower is guided by the second cam. In the third state, at least part of the first cam follower enters a space formed by a recess portion or a hole portion.

1. Technical Field
The technology disclosed herein relates to a lens barrel that supports an optical system.
2. Background Information
There are known lens barrels that support an optical system with which the focal distance can be varied. For example, the lens barrel disclosed in Japanese Laid-Open Patent Application 2007-219304 comprises a first moving cam ring in which a cam groove is formed, and a first group lens barrel that supports a first lens group. The first group lens barrel has a follower pin that engages in the cam groove. With this lens barrel, the first moving cam ring and the first group lens barrel allow the first lens group to be moved in the optical axis direction with respect to the first moving cam ring.
A cam mechanism featuring a cam follower and a cam groove is employed in this type of lens barrel. For example, the cam mechanism has three cam followers and three cam grooves. The cam followers are guided in the cam grooves, so that the two frame bodies more relatively in the optical axis direction. To achieve a higher zoom ratio, it is preferable to lengthen the distance that the two frame bodies move relatively in the optical axis direction.
However, to lengthen the distance that the two frame bodies move relatively in the optical axis direction, the lengths of the two frame bodies in the optical axis direction have to be increased, so if an attempt is made to increase the zoom ratio, the lens barrel ends up being larger in the optical axis direction.
It is an object of the technology disclosed herein to provide a lens barrel with which the zoom ratio can be increased while minimizing the increase in size.

Panasonic Intellectual Property Management Co., Ltd.


A structure of hybrid heating equipment according to the present invention is disclosed. The present invention combines a multiple of the thermal sources for heating the interior materials of the container simultaneously, and assures the materials could gain the thermal energy uniformity. Furthermore, the present invention allows users to control the level of the heating simply through adjusting the length of interior heating elements or the flow rate of the incoming gas. In addition, the present invention connect with the tubes of the hot exhaust gas to further lower the influence of the thermal resistance by coordinating the flow of the hot exhaust gas, therefore fully reflect the advantages of the conserving energy and reducing the carbon emissions by reusing the waste heat as the principal source while the electric heating devices as supplement.

At present, most heating apparatuses supply a single type heat source to heat the tanks. Popular configurations include disposing devices such as heat sources, quartz tubes or electrical heating plate below the heating tanks. By burning fuels directly or converting electrical energy to thermal energy, the heat is transferred indirectly via the tank bodies of the heating tanks to the materials inside.
In this heating mode, the material closest to the bottom of the heating tank receives the thermal energy first and the temperature is gradually increased earlier than others. If the materials are in liquid state during the heating process, it is possible to transfer the heat through convection, thus the temperature of the overall materials can be increased more uniformly.
Nonetheless, liquid material with a high viscosity would hinder convection in the heating process. Consequently, the thermal energy provided by the heat sources may concentrate excessively in the region close to the bottom of the heating tanks and lead to nonuniform heating. Some materials may deteriorate due to overheating caused by heat retention.
When the heated materials are granular materials the contact areas among granules are small and nonuniform, resulting in increased thermal resistance (R), which becomes a great obstacle for heat transfer. The thermal resistance is defined as ΔT/q (° C./W or K/W), where ΔT(=Ti−To) is the temperature difference between two contact surfaces and q is the thermal transfer energy. Here, the thermal resistance Rt of the whole system includes the conduction part Rcd and the convection one Rcv. The conduction thermal resistance Rcd represents the resistant effect when heat is transferred by conduction. Taking heat transfer through filter granules as an example, the conduction thermal resistance is defined as Δx/(kA), where Δx is the thickness or distance of the thermal conductor, k is the thermal conductivity, and A is the thermal conduction area in-between. In addition to the interfaces of real contacts between granules, there are gaps without contacts, where gas flows through and results in extra thermal resistance Rt. The thermal resistance Rt, defined as 1/(hA), is caused by convection between the solid surfaces and fluids, where h is the heat transfer coefficient and A is the heat transfer surface area.
The conduction thermal resistance Rcd and the convection thermal resistance Rcv mentioned above cause obstacles to heat transfer; hence, the influence of the thermal resistances should be eased off in order to improve the heating efficiency. Possible options include improving the structural design of the heating tanks, stirring the granular materials by external work, leading in external hot gas, or changing the form of heat sources.
A method for solving the problems described above is to stir the granular materials by external force. This stirring action is to move the heated granules that are closer to the heat sources to the region with lower temperature, which does not rely on the existing heat transfer paths only. In addition, through stirring the granules with higher temperature can contact those not nearby initially, and thus shorten the heat transfer paths. In other words, the stirring action can mainly reduce the overall system conduction thermal resistance Rcd. During the stirring process, the gas flow among the granules can be driven and thereby slightly reduces the convection thermal resistance Rcv to improve the uniformity of the overall heat transfer. Nonetheless, in practice it is not easy to heat the granular materials close to the top as uniformly as those close to the bottom by simply stirring. Only the spin motion of the whole heating tank can provide sufficient stir. Unfortunately, spin motion is not a commonly available system, and is therefore not applicable to most cases; moreover, its installation and operation costs will raise financial barriers.
Another method is to change the type of the heat sources. For example, the heat source can be made in the type of serpentine tubes, which thus improves the range and region of heat supply. Nonetheless, in industrial heating tanks, even if the serpentine quartz heating tubes are adopted or the tubes filled with high-temperature liquid or gas are being used in the inner walls of said heating tanks, there is still room for improvement for supplying heat to the central part of the heating tanks.
Taiwan Patent Publication Number TW M302002 disclosed a baking apparatus combining two heat sources for baking materials. The appearance of the apparatus is a kiln. Inside the apparatus, the hot gas is led in from the bottom, guided upwards, and passes through a vent for heating. Meanwhile, there are multiple heating platforms disposed therein and heated by electric heaters. Nonetheless, such apparatus combining dual heat sources is only applicable to place a plurality of standalone items. There is no contact between the standalone items for heat conduction. Instead, they are arranged on the electric heaters for heating and baking; hence, the application range is quite limited, and the inner space is not utilized effectively, where materials are not fully filled for uniform heating. Accordingly, a real hybrid heating apparatus still awaits new technology for implementation.
In order to solve current technology problems, the present invention proposes a novel design of structure and method. Considering that the thermal resistance of a system comprises the conduction thermal resistance Rcd and the convection thermal resistance Rcv, the structure of the heating tank is improved and changed, and so that different methods are used for reducing the obstacles in the heat transfer caused by said factors. For the part of the conduction thermal resistance Rcd, according to the present invention, multiple sets of heating bars are inserted into the heating tank concurrently for controlling their distribution and thus reducing the conduction thermal resistance Rcd by enabling the heat to be conducted uniformly in the heating tank. For the problem of the convection thermal resistance Rcv, pipes are disposed for leading hot gas having sufficient thermal energy into the tank for reducing the convection thermal resistance Rcv. By applying both simultaneously, the total thermal resistance Rt of the system is lowered and the thermal efficiency is enhanced. Accordingly, the long-term problem of operation in the heating process of the industry is solved.

Hybrid heating apparatus applicable to the moving granular bed filter

Atomic Energy Council—Institute of Nuclear Energy Research


A distributed block-based programming model for control applications such as multimedia based real-time applications is described. According to one aspect of the invention, user program specifies interconnections between a plurality of program blocks distributed across a plurality of processing nodes. The user program is automatically translated into a system-level program having a program fragment for each one of the processing nodes. Each one of the program fragments comprise the program blocks located on the processing node and one or more system-level blocks for establishing connections between the processing node and a different processing node across a network.

The present invention relates generally to control system applications and more specifically to a system for constructing and distributing block-based program fragments for use in such applications.
A portion of the disclosure of this patent document contains material which is subject to copyright protection. The copyright owner has no objection to the facsimile reproduction by anyone of the patent document or the patent disclosure as it appears in the Patent and Trademark Office patent file or records, but otherwise reserves all copyright rights whatsoever. The following notice applies to the software and data as described below and in the drawings hereto: Copyright (copyright) 1998, Honeywell, Inc., All Rights Reserved.
Multimedia is increasingly recognized as an enabling technology with diverse applications from interactive training to medical diagnosis, for example. However, the use of multimedia in control applications has received little attention. A driving force behind the inclusion of multimedia in control applications is the need for sensing higher order material and product properties. In high value added processes such as composite synthesis and semiconductor manufacturing, higher order material and product properties such as look, feel, consistency, and uniformity serve as quality measures for control. Many such property measurements can be inferred by correlating the outputs of multimedia sensors.
In the context of control applications, the term xe2x80x9cmultimediaxe2x80x9d implies a much broader scope than the traditional usage of the term that refers to audio, video and text. In the context of control applications, multimedia encompasses both image data and spectral data. Image data refers to still images, full-motion video, voice, graphics and text data. Image data is obtained from sources such as video, X-ray, and scanning electron microscopy to name a few. Spectral data refers to sensor data. Spectral data is obtained from sources such as infrared, color, acoustic emission, ultrasound, microwave, laser, and other optical devices, for example.
Examples of areas in which control applications using multimedia information can improve product yield and quality include: advanced composite materials, semiconductors, metal processing, pulp and paper industry, petroleum and refining, and virtual reality. Multimedia information is used in such control applications in many ways. For example, multimedia information is used for direct and indirect measurements of quality, as a means of improving process alarm management, and for implementing more effective control strategies such as Multiple-Input Multiple-Output (MIMO) control. In particular, MIMO control using multimedia and spectral sensor data allows control systems to operate on higher level, often intangible, properties of a product such as look, feel, and sound.
A MIMO control strategy refers to the simultaneous processing of multiple sensors (inputs) and actuators (outputs) to provide globally optimal control. This requires that multiple inputs and outputs be synchronized within specified time constraints and in turn places more performance demands on the underlying network. Due to processing and communications limitations, MIMO implements are used currently only for small processes.
What is needed is a network architecture that will support distributed control systems that will operate directly on multimedia data. What is also needed is a programming model for multimedia based MIMO control applications.
A distributed block-based programming model is described. According to one aspect of the invention, a user program is received. The user program specifies interconnections between a plurality of program blocks distributed across a plurality of processing nodes. The user program is translated into a system-level program having a program fragment for each one of the processing nodes. Each one of the program fragments comprise the program blocks located on the processing node and one or more system-level blocks for establishing connections between the processing node and a different processing node across a network.
According to another aspect of the invention, a user program specifying connections between a plurality of program blocks distributed across a plurality of processing nodes is received. At least one program block located on a root processing node is identified. The root node is the processing node controlling execution of the program. The input and output connections from each one of the program blocks located on the root node are traced. Connection between one of the program blocks located on the root processing node and one of the program blocks located on a remote processing node are identified. A first system-level block is inserted on the root processing node. A second system-level block is inserted on the remote node. The first and second system-level blocks provide network services. A program fragment is created for the processing nodes. The program fragment for each processing node comprises the program blocks and the system-level blocks located on the processing node.
Therefore, one aspect of the present invention provides a method of automatically creating and executing distributed programs based on a block based programming model. Another aspect of the invention provides centralized control for the distributed application. Still other and further embodiments, aspects and advantages of the invention will become apparent by reference to the drawings and by reading the following detailed description.

System for constructing and distributing block-based fragments


An apparatus for measuring particle size distribution includes a charging device and a precipitator. The charging device includes a corona that generates charged ions in response to a first applied voltage, and a charger body that generates a low energy electrical field in response to a second applied voltage in order to channel the charged ions out of the charging device. The corona tip and the charger body are arranged relative to each other to direct a flow of particles through the low energy electrical field in a direction parallel to a direction in which the charged ions are channeled out of the charging device. The precipitator receives the plurality of particles from the charging device, and includes a disk having a top surface and an opposite bottom surface, wherein a predetermined voltage is applied to the top surface and the bottom surface to precipitate the plurality of particles.

The subject matter disclosed herein relates generally to monitoring particles and, more particularly, to monitoring exposure to small particles, such as nanoparticles, using miniaturized personal devices.
Particles in the submicron and nanometer size range have been reported in the exhausts of different combustion sources, chemical processes and aerosol reactors. Examples include the exhausts of diesel and jet engines, the emission from coal-combustion power plants, and welding fumes. Such nanoparticulate matter is considered environmental pollution, and thus harmful. Separately, many modern industrial applications have begun to utilize nanoparticles as part of a growing technology. For example, the photocatalysis of nano-sized TiO2 has been proposed or implemented for many practical applications including bacteria sterilization, oxidation of soot particles, decomposition of kitchen oils, super-hydrophilic surface coating, and hydrogen production. Nanoparticles of different materials are synthesized in chemical reactors for a variety of modern industrial, and are the building blocks for the recent national initiative in nanotechnology in the United States. Meanwhile, the number of scientific publications on the toxicity of newly synthesized nanoparticles is increasing. Workers in current and future nanotechnology-related manufacturing facilities are increasingly likely to be exposed to nanoparticles. Low-cost, miniaturized personal devices for monitoring exposure to nanoparticles are lacking in the art.

Miniaturized ultrafine particle sizer and monitor