Showing papers on "Offset (computer science) published in 2002"

Image forming device

Abstract: PROBLEM TO BE SOLVED: To provide an image forming device that can ensure uniformity of a resolution in the lens arrangement direction while maintaining a high basic resolution thereby making an uneven gray scale inconspicuous even in the case of processing half-tone SOLUTION: An object face 14 is placed to be opposed to a one lens end face of a rod lens array 10 and an image face 16 is placed to be opposed to the other lens end face and the operating distance of the object side and that of the image side are selected optically nearly equal to each other An actual distance TC0 between the object face and the image face is limited between a conjugate length TC1 maximizing the average value MTFave of an MTF (modulation transfer function) of the rod lens array single body in the lens arrangement direction and a conjugate length TC2 minimizing ΔMTF (=(MTFmax-MTFmin)/MTFave) and the offset ΔTC (=|TC0-TC1|) with respect to the conjugate length TC1 maximizing the MTFave is selected within a range of 0 mm<ΔTC<+02 mm

Response Corridors of Human Surrogates in Lateral Impacts

Abstract: Thirty-six lateral PMHS sled tests were performed at 6.7 or 8.9 m/s, under rigid or padded loading conditions and with a variety of impact surface geometries. Forces between the simulated vehicle environment and the thorax, abdomen, and pelvis, as well as torso deflections and various accelerations were measured and scaled to the average male. Mean +/- one standard deviation corridors were calculated. PMHS response corridors for force, torso deflection and acceleration were developed. The offset test condition, when partnered with the flat wall condition, forms the basis of a robust battery of tests that can be used to evaluate how an ATD interacts with its environment, and how body regions within the ATD interact with each other.

Distance measurement using half-duplex rf techniques

Abstract: A system, apparatus, and method for determining the distance between two objects using an indirect propagation delay measurement is disclosed. A frequency hopping scheme (such as the Bluetooth™ technology) is used to measure the relative phase offset of the received signal between the various frequencies. For a given distance between the objects, the phase offset vs. frequency curve is a straight line with the slope dependent upon the measured distance. After the phase of the received signals is detected, the data is plotted on a curve and the slope is calculated. A wireless slave device remains phase locked with another device in a half-duplex communication mode by employing a low-drift phase locked loop employing a voltage controlled crystal oscillator. The phase locked loop further employs a mechanism that provides immunity from transitory phase slip at a time when the loop is opened.

Calculating camera offsets to facilitate object position determination using triangulation

Abstract: A touch system includes a reference frame, and at least two cameras having fields of view that overlap within the reference frame. The position of an object relative to the reference frame is determined from captured images of the object based on triangulation. The fields of view of the at least two cameras are rotated with respect to the coordinate system of the reference frame to define offset angles. The touch system is calibrated by: capturing an image of the object using each the at least two cameras at least one location within the reference frame; and for each location: determining the position of the object within each image, the position of the object within each image being represented by an angle φ, the angle being equal to the angle formed between an extremity of the field of view extending beyond the reference frame and a line extending from the camera that intersects the object within the image; and mathematically calculating the offset angles of the at least two cameras based on the angle determined for each image and the position of the at least two cameras relative to the coordinate system assigned to the reference frame.

Method and apparatus for correcting crosstalk and spatial resolution for multichannel imaging

Abstract: A multichannel imaging system generates an ensemble of images for each field of view of an object (401). Each image in the ensemble is intended to contain information from only one source among a plurality of sources for the object. However, due to crosstalk, at least a portion of the signal from a first source appears in a channel intended for a second source (404). Because the accuracy of the correction will be degraded if the images in an ensemble are spatially misaligned with respect to one another, the spatial offset between images is determined (408) and a correction is applied to substantially eliminate the offset. Then, a correction to the signals is determined to substantially reduce the contributions to the signal in a channel from the signals in other channels. The signal processing can be employed to process the output signals for each of a plurality of different disclosed imaging systems (409).

Seismic data mapping and reconstruction

Abstract: Seismic data mapping uses data at source and receiver locations one actually has to create or simulate data at the locations one desires to have. The process is similar to seismic migration, though less demanding in that only data relatively near to the desired output point need be employed. Basic data mapping adjusts phase and amplitude of the data to conform to the geometry at the output location under the assumption that reflectivity does not change with angle of incidence. Full seismic data reconstruction goes beyond basic data mapping by also allowing reflection coefficients to change with incident angle. In the straight-raypath approximation, both data mapping and full data reconstruction are Kirchhoff-like operations of small integration aperture, with data mapping the simpler of the two. Operating on moveout-corrected data, they are (up to a point) velocity independent. The operators can map or continue data from one offset to another [dip moveout (DMO) being a special case of data mapping] or from one source or receiver location to another. Both 2-D and 3-D versions of the operators can be constructed. The 2-D mapping and reconstruction operators apply when input and output offset azimuths are aligned. The 3-D operators are equivalent, at least in principle, to two passes of the corresponding 2-D operators: the first pass a DMO to zero offset, the second an inverse DMO to the desired location. Potential uses for data mapping and reconstruction include filling in missing data, regularizing a data set, consolidating to a smaller data set, removing acquisition footprints, and so on.

Memory module with offset data lines and bit line swizzle configuration

Abstract: A memory module includes an array of N memory devices, each memory device having M data pins, where N is greater than M, and M and N are positive integers; and N bit lines traversing the array of N memory devices, such that each one of the N bit lines is connected to M of the N memory devices.

Self-heating/self-cooling package

Abstract: A flexible temperature changing package (30) for heating or cooling a contained item (12) or product including a temperature changing element (5) adjacent to the item and an offset activation point (40) that prevents damage to item.

Thermomagnetic residual offset in integrated Hall plates

Abstract: Integrated Hall plates show self-induced offset due to the current flow in their current leads. The magnetic field surrounding these current leads generates a magnetic offset signal, while their resistive heating causes thermoelectric offset voltages. This paper reports experimental results on these two effects. They are obtained using a novel test structure enabling to separate the two contributions. In addition, the experimental results concerning the thermal behavior of the test structure are compared with finite element (FE) simulations.

A study of joint tracking algorithms of carrier frequency offset and sampling clock offset for OFDM-based WLANs

Abstract: We present three joint tracking algorithms of carrier frequency and sampling clock offsets for OFDM-based WLAN systems, such as IEEE 802.11a standard. In such systems, one symbol usually contains a few pilots so that the estimation accuracy and robustness of conventional methods do not satisfy the system requirement. In this paper, three joint tracking algorithms for accurate frequency and sampling estimation are presented. The first method is performed by a one-dimensional least square estimation and averaging over L symbols. The second algorithm compares the phase difference of the current symbol with the subsequent D-th symbol and gives better performance, especially when the SNR or synchronization offset is smaller. The third method uses two-dimensional linear least square estimation within the frequency and time domains. Simulations using these algorithms have been performed with 16-QAM modulation schemes. Simulation results show that the three algorithms can improve the estimation accuracy and robustness.

Azimuthal AVO: Methodology and data examples

Abstract: Azimuthal AVO (AVOA) has become a popular method of fracture detection in both carbonate and sandstone reservoirs. Previous methods often relied on stacking the multiazimuth data into offset and azimuth bins, often using only two azimuth sectors perpendicular to each other. This can mix the data over a significant azimuth range and does not allow for meaningful error estimates. Once the data have been stacked into azimuth bins, information on azimuthal distribution is lost. Each azimuth sector is treated as if it has equal weight, even though one sector may have significantly lower fold and thus a lower signal-to-noise ratio. It has also been suggested that the results of azimuth sectoring analyses are often influenced by acquisition geometry.

Maskless lithography with sub-pixel resolution

Abstract: Maskless microlithography provides a sub-pixel voting system using multiple, slightly-offset, digitally-controlled, unit-pixel, partial exposures with cumulative voting to identify regions of full exposure for sub-pixel-selection. Computer control of a virtual-mask pixel-selection device of unit-pixel resolution usually provides pixel-resolution patterns. To achieve sub-pixel resolution, the virtual mask, after a first partial exposure, is offset by less than a pixel-width and a second partial exposure is made. If the offset is ½ pixel-width, the result is a half-pixel size image region of full exposure. Finer voting can be defined by number of pulses, by significantly changing the offset, by offset in another dimension, and by increasing the multiplicity of exposures, thus enabling resolution enhancement by large multiples. The offsetting techniques can also be used to drill controlled-depth vias or to provide topography controls for laser-milling.

Method and apparatus for using an alignment target with designed in offset

Abstract: An alignment target includes periodic patterns on two elements. The alignment target includes two locations, at least one of which has a designed in offset. In one embodiment, both measurement locations have a designed in offset of the same magnitude but opposite directions. For example, two separate overlay patterns that are mirror images of each other may be used. Alternatively, the magnitudes and/or directions may vary between the measurement locations. The radiation that interacts with the measurement locations is compared. The calculated difference is extremely sensitive to any alignment error. If the difference between the patterns is approximately zero, the elements are properly aligned. When an alignment error is introduced, however, calculated difference can be used to determine the error. In one embodiment, the alignment target is modeled to determine the alignment error. In another embodiment, additional overlay patterns with additional reference offsets are used to determine the alignment error.

Scene-based non-uniformity offset correction for staring arrays

Abstract: An approach for processing image data is described. The method comprises correcting a frame of image data received from a detector using existing correction coefficients that comprise a plurality of offset coefficients corresponding to a plurality of detector elements. The method also comprises calculating an update parameter for each detector element using pixel data generated from the correction. The update parameter for a given detector element is calculated from multiple difference values determined from a given pixel value of the pixel data and multiple adjacent pixel values. The given pixel value corresponds to the given detector element. Each difference value is determined by subtracting one of the multiple adjacent pixel values from the given pixel value. The method comprises identifying offset coefficients whose existing values are to remain unchanged based upon the update parameters and changing existing values of offset coefficients other than those identified to remain unchanged.

Apparatus and method for address calculation

Abstract: A dual-cycle address generation unit is described to generate linear addresses The dual-cycle address generation unit includes a first adder to add a product of an index and a scaling factor to an offset and a segment base during a first clock cycle and a second adder to add output of the first adder with a base during a second clock cycle

Object-based bit rate control method and system thereof

Abstract: An object-based bit rate control method and a system therefore provides a user with satisfactory quality of image by using significance of the object. The object is separated from the image, and significance is imposed on each object. A quantization parameter is differently varied according to the significance of the object. Especially, a variable width of the quantization parameter is controlled in a boundary region of the object and the other regions.

High-speed differential sampling flip-flop

Abstract: A high-speed differential sampling flip-flop includes a differential data input, a differential offset control input, a sampling clock input, an output, a sampling latch, and an RS latch. The sampling latch includes a sampling latch reset circuit, a current steering circuit, first and second switches, and a regenerative latch. The sampling latch reset circuit is coupled to a first power supply and the current steering circuit. The current steering circuit has first and second control terminals which are coupled to the differential data input. The first switch is coupled between the current steering circuit and a second power supply. The regenerative latch is coupled to the current steering circuit, the second switch, and a third power supply. The sampling latch also includes first and second offset control current sources coupled to the current steering circuit and the second power supply, and having first and second control terminals coupled to the differential offset control input. The RS latch includes two cross-coupled nand gates and is coupled to the sampling latch and the output. On a transition of the sampling clock input from logic low to logic high, the differential data input is sampled, amplified to a low or high logic level, and transferred to the output. The differential offset control input is used to control the input offset of the sampling flip-flop.

Intelligent ultra high speed distributed sensing system and method for sensing roadway markers for intelligent vehicle guidance and control

Abstract: Methods and apparatus to sense both discrete and continuous magnetic reference systems installed in the roadway, and provide information to support lateral and, to some extent, longitudinal and vertical vehicle control and/or driver assistance. The position of an object, such as a vehicle, relative to a magnetic reference infrastructure, such as that representing a dividing line on a roadway, is determined by sensing, with a sensor associated with the object, at least one axial field strength component of the magnetic field emitted from the magnetic reference, computing a ratio of the sensed axial field strength components, and then determining the positional offset of the object as a function of the ratio. The lateral offset is independent of the magnetic field strength due to the use of the ratio which cancels out the magnetic field strength. The invention is also capable of providing three-dimensional positioning relative to a magnetic reference.

Designing classical offset Cassegrain or Gregorian dual-reflector antennas from combinations of prescribed geometric parameters

Abstract: This paper proposes a simple procedure for the design of classical offset Cassegrain or Gregorian dual-reflector antennas from combinations of prescribed geometric parameters. This procedure has already been applied to classical Cassegrain and Gregorian antennas, to classical displaced-axis Cassegrain and Gregorian antennas, and to classical offset Dragonian antennas. The antenna systems can be fully characterized by 21 parameters, of which only five need to be provided by the antenna designer, as the remaining 16 parameters can be derived in closed form using the procedure described here. In this paper, we assume that the main reflector has a circular aperture, while the subreflector has an elliptical aperture All the antenna geometries presented satisfy the Mizugutch condition (1976), which is the geometric-optics condition for zero cross-polarized radiation. This procedure is very close to the one used for offset Dragonian systems, but all the relevant information is repeated here for completeness.

Gravity based online calibration for monolithic triaxial accelerometers' gain and offset drift

Abstract: In most industry process, periodic sensor calibrations are required to assure sensors working properly. Real-time, online calibration processing for accelerometer is usually needed in some special situation. The paper presents a new and simple method for monolithic triaxial accelerometer gain and offset drift calibration. The procedure uses the fact that the modulus of the inertial mass of the triaxial accelerometer equals 1g under static conditions. The paper consider a state estimate problem where the measure equation is linear but the sensor has a time-varying gain and offset In our study, the input noises of the accelerometers existed in signals are also considered in the calibration procedure.

Cellular system, base station, mobile station and communication control method therefor

Abstract: Growth of interference wave power resulting from the growth of transmission power of the DPCH is prevented to increase line capacity while increasing reliability of control information When a base station compares the reception SIR of the DPCH 1 from a mobile station with the desired SIR of the base station, and the reception SIR is smaller than the desired SIR as a result of the comparison, the base station instructs the mobile station to increase transmission power when the DPCH 1 is sent from the base station to the mobile station, but the base station increments the desired SIR by a predetermined offset value (Δ) when the HS-PDSCH is sent from the base station to the mobile station Consequently, the mobile station increases transmission power compared to the case where only the DPCH 1 is received Also, the HS-PDSCH is sent to each mobile station in different timing, and therefore only the mobile station increases transmission power

Tone scale adjustment of digital images

Abstract: A method of processing data from a digital image to enhance the neutral tonescale estimates a neutral offset, a neutral gain and a neutral gamma from the input data and uses these estimated values to transform the input image data.

Offset projection for slim rear projection displays

Abstract: An offset rear projection display system for displaying an image of an object as a projected image includes a projection lens optically offset from the center of the object, a screen including a light spreading layer, and a mirror disposed to reflect the projected image of the object projected by the projection lens onto the screen.

Method and apparatus for temperature compensation of an uncooled focal plane array

Abstract: A temperature dependent focal plane array operates without a temperature stabilization cooler and/or heater over a wide range of ambient temperatures. Gain, offset and/or bias correction tables are provided in a flash memory in memory pages indexed by the measured temperature of the focal plane array. The memory stores a calibration database, which is accessed using a logic circuit which generates a memory page address from a digitized temperature measurement of the focal plane array. The calibration database is comprised of an array of bias, gain and offset values for each pixel in the focal plane array for each potential operating temperature over the entire range of potential operating temperatures. The bias, gain and offset data within the database are read out, converted to analog form, and used by analog circuits to correct the focal plane array response.

A robust synchronization procedure for blind estimation of the symbol period and the timing offset in spread spectrum transmissions

Abstract: In the context of spectrum surveillance (non cooperative context), a robust synchronization procedure is presented, in order to estimate the period symbol and timing offset of a direct sequence spread spectrum signal. Experimental results are given to illustrate the performances of the algorithm.

Estimation of clock offset from one-way delay measurement on asymmetric paths

Abstract: As the Internet is shifting towards a reliable QoS-aware network, accurately synchronized clocks distributed on the Internet are becoming more significant. The network time protocol (NTP) is broadly deployed on the Internet for clock synchronization among distributed hosts, but is weak in asymmetric paths, i.e., it cannot accurately estimate the clock offset between two hosts when the forward and backward paths between them have different one-way delays. In this paper, we focus on estimating the offset and skew of a clock from one-way delay measurement between two hosts, and propose an idea for improvement of such estimations, which reduces estimation errors when the forward and backward paths have different bandwidths, a major factor in asymmetric delays.

Computing non-self-intersecting offsets of NURBS surfaces

Abstract: A new approach for the computation of non-self-intersecting offset surface of a single G 1 continuous NURBS surface has been presented. The approach recognizes special surfaces, i.e. planes, spheres, cones and cylinders, and offsets them precisely. An approximate offset surface within the specified tolerance is computed for a general free form surface. The method for a general free form surface consists of (1) sample offset surface based on second derivatives; (2) eliminate sample points which can give self-intersections; (3) surface fitting through the remaining sample points; and (4) removal of all the removable knots of the surface. The approach checks for self-intersections in the offset surface and removes the same automatically, if any. The non-self-intersecting offsets for surface of extrusion and surface of revolution are obtained by removing the self-intersections in the offset generator and profile curves respectively using point sampling, cleaning of sampled points, curve fitting and knot removal. The approach has better control on error. It generates offset surface with less number of control points and degree. The methodology works only for a class of problems where in the offset of a single G 1 surface is still a single connected surface without having any holes. The offset methodology has been demonstrated through three types of surfaces namely surface of revolution, surface of extrusion and a general free form surface. This approach has been extensively used in creation of offset surfaces of composite laminate components. The presented approach can also be used to check for self-intersections in any general surface and to remove the same, if any, with little modifications, as long as the cleaned surface is a single connected surface.

Array access boundary check by executing BNDCHK instruction with comparison specifiers

Abstract: The present invention provides a method and apparatus for executing a boundary check instruction that provides accelerated bound checking. The instruction can be used to determine whether an array address represents a null pointer, and whether an array index is less than zero or greater than the size of the array. Three extensions of a boundary check instruction are provided, with each performing a different combination of three boundary check comparisons. One comparison compares a first operand, which may contain the base address of an array, to zero. Another comparison evaluates the value of a second operand, which may contain an index offset, to determine if it is less than zero. The other comparison evaluates whether the value of the second operand is greater than or equal to a third operand. The third operand may indicate the size of an array. A trap is generated if any of the comparisons evaluates to true.