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Pattern decomposition method (PDM) may be thought to be a type of spectral mixture analysis in which each pixel is expressed as the linear sum of fixed, standard spectral patterns. The usage of fixed standard spectral patterns makes possible the comparison of data from different time and also from different sensors with the same criteria. In the development of the PDM, I introduced new point of view to interpret the PDM. It is multi-dimensional analysis. In a sense, the standard patterns in the PDM are thought as a kind of principal axes in n-dimensional space but have physical meaning. To make it possible, the PDM adopts an oblique coordinate system. The standard patterns are the axes of the coordinate system. There is another mathematical analysis method that uses oblique coordinate system. It is factor analysis method. In factor analysis, there is an algorithm that extracts meaningful factors in oblique coordinate system. In this paper, I apply this algorithm to Landsat/TM data and show the obtained factors are quite similar to the three standard patterns of the PDM.

In the medical ultrasound imaging, the synthetic transmit aperture (STA) technique is very promising and has been a hot research topic. It is dynamically focused in both transmit and receive yielding an improvement in resolution. But this imaging technique sets high demands on processing capabilities and makes implementation of a full STA system very challenging and costly. Many attempts have been made to reduce the demands on the system making it a more realistic task to implement. In this paper we don’t consider how to reduce the demands, but consider how to accelerate the processing speed of the system. The recent introduction of general-purpose graphic processing units (GPU) seems to be quite promising in this view, especially for the affordable programming complexity. In this paper we explain the main computational features of STA processing unit, trying to disclose the degree of parallelism in the operations. On the basis of the compute unified device architecture (CUDA) programming model and the extremely flexible structure of the Single Instruction Multiple Threads (SIMT) model, we show that the optimization of STA processing unit can be performed more efficiently. The input data is read from Matlab, the post-processing and display also use Matlab. Performance shows that, using a single NIVDIA GTX-650 GPU board, this amount to a speed up of more than a factor of 30 compared to a highly optimized beamformer running on our test workstation with a 3.20-GHz Intel Core-i5 processor.

This paper presents a proposal of a protocol for communication between the read-out integrated circuit for the STS (Silicon Tracking System) and the Data Processing Board (DPB) at CBM (Compressed Baryonic Matter) experiment at FAIR, GSI (Helmholtzzentrum fuer Schwerionenforschung GmbH) in Germany. The application background, objectives and proposed solution is presented.

Widespread employment of industrial lasers in manufacturing operations has occurred as a result of the technical and economic advantages of the processes. This paper discusses the positive economic factors which singly, or in combination, justify the purchase of a laser for a manufacturing application. Examples of recent industrial installations are cited as evidence of the cost effectiveness of laser processing.

This paper proposes a method for the design of governor foot mechanism on high-speed printing press. According to the technological conditions, an optimal design model is presented to achieve the minimum deviation between the desired and actual track points. The physical dimensions of the linkages and the angular stroke of the driven cam can be gained by solving the presented optimum model.Then the driven cam’s profile is calculated. The effectiveness of the proposed method is proved through an illustrative design example of a governor foot mechanism for high-speed operation . Keywords: Cam-Linkage Mechanisms, Optimum Design, Governor Foot Mechanism, Printing Press. 1. INTRODUCTION In high-speed offset press, the feed system has the task of picking up the sheets from the feed pile, separating them via suction head, conveying them to the feed table, and aligning them at the feed guides [1]. The suitable design of this feed system is very important to ensure the precision of overprint and the quality of the press products, especially in high-speed operation. The governor foot mechanism is one of the key components of the suction head, which is used to separate the sheets and convey them to the feed table one by one. The suction head, also called feeder, has another two main components besides governor foot: lifting sucker and forwarding sucker. Each individual sheet is separated via the well coordinating of them: (1) the lifting sucker lifts the first sheet at the top of the feed pile; (2) the governor foot steps on the top surface of the rest of the feed pile, then its blower blows to help the lifting sucker separate the first sh eet completely; (3) the forwarding sucker moves back, gets the sheet from the lifting sucker, and conveys it to the feed table, (4) the governor foot makes way to the lifting sucker, the latter moves down to suck the second sheet up. Via these repeated technological actions, the sheets are separated and conveyed to the feed table one by one. In the process of stepping on the surface of the feed pile, the governor foot also has task of detecting the height of the pile, a signal will be sent from time to time, and the feed pile will be lifted accordingly to keep its height and en sure the successive separating of sh eets and normal printing process. It is obvious that the structural design, accuracy of manufacturing, the kinetic and dynamic characteristic of the suction head will affect the performance of the printing press in many aspects, such as the printing speed, the precision of overprint and of paper sheet changeover, and the quality of the press products, etc [1]. Hence, as one of the key components of the feeder, suitable design is needed for the governor foot mechanism. Cam-linkage mechanisms are widely used to meet the requir ements of the governor foot used in the feed system on printing press. As shown in Fig.1, is a diagrammatic sketch of a widely used design scheme of the governor foot mechanism. When the driven cam rotates, its follower will swing up and down around a fixed central pointA , and through the planar linkage mechanism, the link foot F P will accordingly complete a series of movements such as stepping on the feed pile, staying for a while and blowing to help the lifting sucker separate the sheet at the top of the pile, and leaving away to let the lifting sucker separate another sheet, etc. This paper proposes a method to solve this kind of design problem. In section 2, we first explain the requirements to the trajectory path of the foot link F P , and then present an optimum model, which is used to achieve the mi nimum deviations between the desired and actual track points of the foot link, to synthesize the linkages’ dimensions and the angular stroke of the driven cam. In section 3, we present the parametric expressions for the driven cam profile. An illustrative design example based on the proposed method is given in section 4, and the effectiveness of the design method was proved by the calculation results. This proposed

Structural Health Monitoring aims to characterize the performance of a structure from a combination of recorded sensor data and analytic techniques. Many methods are concerned with quantifying the elastic response of the structure, treating temperature changes as noise in the analysis. While these elastic profiles do demonstrate a portion of structural behavior, thermal loads on a structure can induce comparable strains to elastic loads. Understanding this relationship between the temperature of the structure and the resultant strain and displacement can provide in depth knowledge of the structural condition. A necessary parameter for this form of analysis is the Coefficient of Thermal Expansion (CTE). The CTE of a material relates the amount of expansion or contraction a material undergoes per degree change in temperature, and can be determined from temperature-strain relationship given that the thermal strain can be isolated. Many times with concrete, the actual amount of expansion with temperature in situ varies from the given values for the CTE due to thermally generated elastic strain, which complicates evaluation of the CTE. To accurately characterize the relationship between temperature and strain on a structure, the actual thermal behavior of the structure needs to be analyzed. This rate can vary for different parts of a structure, depending on boundary conditions. In a case of unrestrained structures, the strain in the structure should be linearly related to the temperature change. Thermal gradients in a structure can affect this relationship, as they induce curvature and deplanations in the cross section. This paper proposes a method that addresses these challenges in evaluating the CTE.

Recently, optical burst switching and aggregated optical packet switching have gained significant exposure as possible future mechanisms for routing aggregated IF traffic over all-optical core networks. However, the limited buffering capacity in all-optical networks presents a major challenge, as current IP traffic displays strong self-similar properties. Reducing the burst loss rate of such long-range dependent traffic can be costly requiring asignificant increase in either the network bandwidth or the buffer size of optical cross connects. In this paper, we revisit the possibility of using buffers to reduce self-similarity before the traffic is routed onto the all-optical core. The aim of this paper is to increase the understanding of the effect of packet/burst aggregation on the self-similarity measure of the traffic. In particular, we implement a simple burst assembly mechanism with twoparameters, the maximum burst length L and the maximum burst delay d, so that incoming traffic is smoothed

Coherent combining is a novel approach to scale the performance of laser amplifiers. The use of ultrashort pulses in a coherent combining setup results in new challenges compared to continuous wave operation or to pulses on the nanosecond timescale, because temporal and spectral effects such as self-phase modulation, dispersion and the optical path length difference between the pulses have to be considered. In this paper the impact of these effects on the combining process has been investigated and simple analytical equations for the evaluation of this impact have been obtained. These formulas provide design guidelines for laser systems using coherent combining.

Two dynamic characteristics, on-line map update and real time traffic information, are currently considered as the most important feature of vehicle navigation system. Therefore, the need of incorporating dynamic information into vehicle navigation system should be emphasized because the lack of data representation to integrate navigation data with models for spatio-temporal processes appears to be a major shortcoming in traditional vehicle navigation system. Consequently, in this paper we briefly summarize spatial and temporal characteristics of the DVNS (Dynamic Vehicle Navigation System). And then, based on these summaries, we propose a data model with spatio-temporal characteristic instead of static data model. In this data model, spatial feature, temporal feature and traffic feature are all integrated into a unified data model in order to supporting dynamic route plan and on-line map update in the DVNS. Finally, a prototype system based on the proposed data model is tested and implemented.

The active alignment of fast axis collimator lenses (FAC) is the most challenging part in the manufacturing process of optical systems based on high power diode laser bars. This is due to the high positioning accuracy in up to 5 degrees of freedom and the complex relations between FAC misalignment and properties of the resulting power density distribution. In this paper an experimental approach for FAC alignment automation is presented. The alignment algorithm is derived from a beam propagation model based on wave optics. The model delivers explicit relations between FAC misalignment and properties of the distorted power density distribution in the near and far field. The model allows to calculate the FAC misalignments and to correct them in one or multiple steps. The alignment algorithm is tested with a demonstrator system. The demonstrator contains an optical system which allows a real time analysis of the near field and far field power distribution of individual emitters. For the tests two different types of FAC lenses and high power diode laser bars are used. The FAC lenses are prealigned within a range of ±50 μm and 0.5 degree around the suitable position. During the automated alignment process the translational and rotational remaining misalignment and the properties of the far field power density distribution are recorded. The experimental results are evaluated regarding reliability and flexibility of the presented FAC alignment algorithm.

Rapid advancements in cost effective sensors and micro computers are now making practical the on-line implementation of pattern recognition based systems for a variety of industrial applications requiring high processing speeds. One major application area for real time pattern recognition is in the sorting of packaged/cartoned goods at high speed for automated warehousing and return goods cataloging. While there are many OCR and bar code readers available to perform these functions, it is often impractical to use such codes (package too small, adverse esthetics, poor print quality) and an approach which recognizes an item by its graphic content alone is desirable. This paper describes a specific application within the tobacco industry, that of sorting returned cigarette goods by brand and size.

A frequently used assessment method of skeletal age is atlas matching by a radiological examination of a hand image against a small set of Greulich-Pyle patterns of normal standards. The method however can lead to significant deviation in age assessment, due to a variety of observers with different levels of training. The Greulich-Pyle atlas based on middle upper class white populations in the 1950s, is also not fully applicable for children of today, especially regarding the standard development in other racial groups. In this paper, we present our system design and initial implementation of a digital hand atlas and computer-aided diagnostic (CAD) system for Web-based bone age assessment. The digital atlas will remove the disadvantages of the currently out-of-date one and allow the bone age assessment to be computerized and done conveniently via Web. The system consists of a hand atlas database, a CAD module and a Java-based Web user interface. The atlas database is based on a large set of clinically normal hand images of diverse ethnic groups. The Java-based Web user interface allows users to interact with the hand image database form browsers. Users can use a Web browser to push a clinical hand image to the CAD server for a bone age assessment. Quantitative features on the examined image, which reflect the skeletal maturity, is then extracted and compared with patterns from the atlas database to assess the bone age.© (2000) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

The MODIS instrument on the Terra and Aqua spacecrafts is a 12 bit sensor with an analog-to-digital (A/D) range of 0 to 4095 DN. Each sensor system is limited by a range at the low and high ends of the dynamic scale. At the low end, quantization noise is the limiting factor whereas at the high end the maximum value is limited by the capability of the amplifier, 4095 in the case of MODIS. However, in both Terra and Aqua MODIS certain detectors in the Reflective Solar Bands (RSB) tend to pre-saturate at a value lower than 4095. This paper serves as a comprehensive report on the algorithms developed to characterize the pre-saturation limit in the RSB. The paper also provides the digital and pre-saturation (analog saturation) limits for the RSB that are currently being used in the Level 1B (L1B) products. The digital and analog saturation limits are well characterized using the Level 1A (L1A) raw Earth-View (EV) data and through the on-board Electronic Calibration (E-CAL). Also, in this paper an analysis is done to study the sensors dynamic range due to the long term changes in the instrument response. In summary, the algorithms and results reported in this paper are important as the radiometric accuracy / uncertainty for instruments such as MODIS, VIIRS (NPP) tends to be coupled to pre-saturation.

The spatial characteristics of noise in X-ray CT can influence object detectability. Now, as three dimensional image reformations become more clinically common, it has become vital to understand the structure of noise in the x, y, and z directions independently. The purpose of this paper is to study noise structure in the radial direction and tangential direction, under varying conditions, including a wedge filter and acquisition techniques (i.e. half scan vs full scan). Because the effect of the reconstruction al gorithm on an image is highly dependent on spatial location w ithin the field of view, the effect of off-center vs centered positioning in each direction is also examined. The noise spatial frequency distribution was investigated via calculation of the noise power spectrum (NPS) through Fourier methods on simulated water images. As expected, noise structure at center was equivalent in both the radial and tangential directions. Towards the periphery, overall noise power was muted. However, in the tangential direction high frequency noise power was preserved more than twice as much as in the radial direction. Towards the periphery noise becomes more low-frequency in the radial direction, while in the tangential direction it becomes more high-frequency. The half scan increased both noise magnitude and low-mid spatial correlation in the NPS compared to full scan. In conclusion, noise spatial structure is directionally dependent off-center and this may have an impact on object detectability in directional reformations. Keywords: x-ray computed tomography (CT), noise, power spectra, spatial uniformity, object detectability.

The complexity of an average electronic circuit pack in industry today has increased immensely in the last several years. The use of surface-mounted devices (SMD) and multilayer circuit packs are the rule, rather than the exception. This acceleration in circuit pack complexity has driven the need for better circuit pack testing. Improvements in design for test (DFT), built-in self-test (BIST), and in-circuit test (ICT) have all contributed to higher yields of electronic circuit packs at the stage where they are first tested following assembly. The percentage of packs to be analyzed is dropping rapidly. Conversely, the task of locating the fault on the population of circuit packs which do have short circuits at this stage has become correspondingly more difficult. In addition, the density of components on the circuit packs has made it more attractive to troubleshoot rather than junk these circuit packs. A technique utilizing computerized color thermography (CCT) has been adopted to physically locate short circuits on these circuit packs. This paper deals with the practical use of CCT at a facility which manufactures and tests populated electronic circuit packs.

In many real-life situations, it is very difficult or even impossible to directly measure the quantity y in which weare interested: e.g., we cannot directly measure a distance to a distant galaxy or the amount of oil in a given well. Since we cannot measure such quantities direcUy, we can measure them indirecily: by first measuring some relatingquantities x1 , . . . , x , and then by using the known relation between x2 and y to reconstruct the value of the desired quantity y.In practice, it is often very important to estimate the error of the resulting indirect measurement. In this paper,we show that in a natural statistical setting, the problem of estimating the error of indirect measurement can be formulated as a simplified (finite—dimensional) version of a tomography problem (reconstructing an image from itsprojections). in this paper, we use the ideas of invariance (natural in statistical setting) to find the optimal algorithm forsolving this simplified tomography problem, and thus, for solving the statistical problem of error estimation forindirect measurements.Keywords: Tomography, error estimation, indirect measurement

The cell phone expansion provides an additional direction for digital video content distribution: music clips, news, sport events are more and more transmitted toward mobile users. Consequently, from the watermarking point of view, a new challenge should be taken: very low bitrate contents (e.g. as low as 64 kbit/s) are now to be protected. Within this framework, the paper approaches for the first time the mathematical models for two random processes, namely the original video to be protected and a very harmful attack any watermarking method should face the StirMark attack. By applying an advanced statistical investigation (combining the Chi square, Ro, Fisher and Student tests) in the discrete wavelet domain, it is established that the popular Gaussian assumption can be very restrictively used when describing the former process and has nothing to do with the latter. As these results can a priori determine the performances of several watermarking methods, both of spread spectrum and informed embedding types, they should be considered in the design stage.

This paper has five purposes. First, to focus upon the key relationships that bound the technology choices for large, archival, digital storage devices; second, to identify the motivations for selecting the optical technology for a petabit-exabit level storage system (10 to the 15th to 10 to the 18th bits); third, to present a generic example and a specific implementation of a terabit-level optical storage device; fourth, to characterize the global design space constraints that will allow one to build a technology-limited optical store; and fifth, to sketch the outline of the BYTERON concept, a wideband 10 to the 16th to 10 to the 17th bit optical store concept and contrast its performance to that of an optical store that is in operation today

Color edge detection is approached in this paper using vector order statistics. Based on the R- ordering method, a class of color edge detectors is defined. These detectors function as vector operators. Specific edge detectors can be obtained as special cases of this class. Various such detectors are defined and analyzed. Experimental results show the noise robustness of the vector order statistics operators. A quantitative evaluation and comparison to other color edge detectors favors our approach.© (1992) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

In recent years, fiber optic sensors have been used for structural health monitoring because of the advantages they have over conventional strain gauges, such as multiplexing capability and immunity to electromagnetic interference (EMI). In addition, they have ability to monitor multiple parameters simultaneously, which is of significant benefit to researchers. However, this diverse sensitivity can cause "cross coupling" leading to imprecision in measurement. In this paper, we report our results on the development and testing of a temperature compensated fiber Bragg grating strain sensor. Results show that the proposed sensor structure can be used to effectively compensate for temperature variations in strain measurement.

Fractal image processing technology has been recognized as having great potential in automatic target recognition (ATR) and image compression. In this paper, Physical Optics Corporation demonstrates the feasibility of using a fractal image processing technique as a new and efficient approach for signature, pattern, and object recognition. Using optical Fourier transform and a ring-wedge detection technique, we generate and measure the power spectral density of an input scene. The log-log plot of the power spectral density vs. spatial frequency provides a very valuable signature for each input. Experimental results show that we can successfully discriminate man-made objects from natural objects in input scenes by analyzing signatures obtained this way.

This paper presents a scheme for estimating two-band amplitude scale attack within a quantization-based watermarking context. Quantization-based watermarking schemes comprise a class of watermarking schemes that achieves the channel capacity in terms of additive noise attacks 1 . Unfortunately, Quantization-based watermarking schemes are not robust against Linear Time Invariant (LTI) filtering attacks. We concentrate on a multi-band amplitude scaling attack that modifies the spectrum of the signal using an analysis/synthesis filter bank. First we derive the probability density function (PDF) of the attacked data. Second, using a simplified approximation of the PDF model, we derive a Maximum Likelihood (ML) procedure for estimating two-band amplitude scaling factor. Finally, experiments are performed with synthetic and real audio signals showing the good performance of the proposed estimation technique under realistic

Paper coatings are porous structures of pigments, binder and air. This research aims at developing a model for the prediction of the bulk optical properties of coating from its structure and material characteristics. Two theoretical approaches have been studied and compared. In both cases the coating is treated as a structured layer consisting of individual scatterers in a medium, and the pores are regarded as scatters. In the first approach they are assumed to be independent. The second approach takes into account that due to their close position the pores are in fact correlated scatterers. The approximation used limits the consideration to pair correlation only. Comparison of the theories to reflectance measurements on polystyrene pigment coatings have uniform pore sizes in the range from 0.13 to 0.95 micrometers showed that for pore size parameters less than 5 the dependent scattering model provides a good prediction for the reflectance, but for larger pore size parameters the reflection behavior approaches that predicted by the independent scattering theory.© (1991) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

This paper describes the TDMA uplink of the ACTS PLANET project, realizing a high split long range access network using optical amplification. An overview of the network topology and the different building blocks is given. In particular, the differentiating burst mode receiver, the optical repeater units and the amplified splitter controller will be discussed. Bit error measurements were performed to define the system limits of the access network. It is shown that a feeder length of 90 km, in combination with a split factor of 2000 and a drop section length of 10 km are feasible.

The Lick Observatory 3-meter telescope has a history of serving as a testbed for innovative adaptive optics techniques. In 1996, it became one of the first astronomical observatories to employ laser guide star (LGS) adaptive optics as a facility instrument available to the astronomy community. Work on a second-generation LGS adaptive optics system, ShaneAO, is well underway, with plans to deploy on telescope in 2013. In this paper we discuss key design features and implementation plans for the ShaneAO adaptive optics system. Once again, the Shane 3-m will host a number of new techniques and technologies vital to the development of future adaptive optics systems on larger telescopes. Included is a woofer-tweeter based wavefront correction system incorporating a voice-coil actuated, low spatial and temporal bandwidth, high stroke deformable mirror in conjunction with a high order, high bandwidth MEMs deformable mirror. The existing dye laser, in operation since 1996, will be replaced with a fiber laser recently developed at Lawrence Livermore National Laboratories. The system will also incorporate a high-sensitivity, high bandwidth wavefront sensor camera. Enhanced IR performance will be achieved by replacing the existing PICNIC infrared array with an Hawaii 2RG. The updated ShaneAO system will provide opportunities to test predictive control algorithms for adaptive optics. Capabilities for astronomical spectroscopy, polarimetry, and visible-light adaptive optical astronomy will be supported.

This paper presents a nonlinear modification of the standard linear adaptive optics controller that greatly reduces the startup lag due to saturation in pyramid wavefront sensors (or any wavefront sensor with 4-cell subapertures). Whenever the pyramid sensor is saturated (as determined by an internal model of the saturation in the controller), the deformable mirror signal is adjusted to quickly remove the saturation of the sensor. When the pyramid sensor is not saturated, a standard linear adaptive optics controller is used to generate the deformable mirror signal. The nonlinear controller is compared with a standard linear controller using a CAOS simulation. It is shown that the startup lag is significantly reduced, and that the steady-state performance is identical to the linear controller.

Next generation EUV optical systems are moving to higher resolution optics to accommodate the smaller length scales targeted by the semiconductor industry. As the numerical apertures (NA) of the optics become larger, it becomes increasingly difficult to characterize aberrations, which broaden the point-spread function and thus limit the ultimate resolution of an optical system. Lateral shearing interferometry (LSI) provides an attractive alternative to conventional interferometric techniques such as point diffraction interferometry due to its experimental simplicity, stability, relaxed coherence requirements, and its ability to scale to high numerical apertures. In this paper we present an analytical solution to the LSI interferogram in various NA regimes. We demonstrate that systematic aberrations present in high NA interferograms due to grating distortion of the diffracted order angular spectrum are measurable and must be compensated for in the reconstruction algorithm.

An iterative reweighted least squares (IRLS) algorithm is presented in this paper for the minimax design of FIR filters. In the algorithm, the resulted subproblems generated by the weighted least squares (WLS) are solved by using the conjugate gradient (CG) method instead of the time-consuming matrix inversion method. An almost minimax solution for filter design is consequently obtained. This solution is found to be very efficient compared with most existing algorithms. Moreover, the filtering solution is flexible enough for extension towards a broad range of filter designs, including constrained filters. Two design examples are given and the comparison with other existing algorithms shows the excellent performance of the proposed algorithm. Published version

The main technological challenge of a future extreme ultraviolet (EUV) light source is the required average power of 115W at the intermediate focus. High repetition rate laser produced plasma (LPP) sources are very promising to face this challenge. We report the current status of the laser produced plasma light source system under development at EUVA. The system consists of the following main components: The plasma target is a liquid xenon jet with a maxium diameter of 50 micrometer and a velocity of more than 35m/s. A Nd:YAG laser oscillating at 1064 nm produces the plasma. The laser is a master oscillator power amplifier (MOPA) configuration with a maximum repetition rate of 10 kHz and an average power of 1 kW. The EUV system currently delivers an average EUV in-band power of 4 W (2% bandwidth, 2π sr) having a stability of 0.54% (1σ, 50-pulse moving average). In order to evaluate a further increase of the repetition rate, xenon jet characteristics and EUV plasma images have been investigated at 10 kHz. In addition, a conversion efficiency of 0.74% (2% bw, 2π sr) has been obtained at low repetition rate operation. This paper presents the progress of our LPP light source development.

This paper introduces our control software design for a tracing system of precise pointing on a balloon-borne telescope to observe the active details on the solar surface. The telescope is an equatorial one with 80 cm in diameter. Borne by balloon, it works at 30 km above the sea level so as to get rid of the image disturbance due to atmosphere. The system contains three parts: basket control, telescope control and tip-tilt control. For telescope control, the crude sensors for pointing detection are two rotating transformers, while the fine sensors two linear CCDs which produce the error signals of pointing. An inserted-type industry-control computer PC104 completes the position close-loop and then drives the servo amplifiers to carry out pointing, searching and tracing automatically. Due to the fact that the position control loop is closed with an improved digital PID arithmetic, the adjustment of the telescope may respond rapidly, therefore the telescope can precisely follow the Sun on the balloon. Simulation test shows that the tracing accuracy may reach as high as 4" (RMS).

In June 1988, the Naval Ocean Research and Development Activity (NORDA) collected some "in-water" data using its Towed Underwater Pumping System (TUPS) in the near-shore waters off St. Andrews State Park, Shell Island, Florida. These in situ data include latitude; longitude; depth in meters; narrow-band upwelling at 465 nm, 507 nm, and 532 nm; broad-band downwelling collected at the surface; temperature; salinity; atid transmissivity. In this paper, we investigate the relationship between depth and the normalized upwelling irradiance (upwelling divided by downwelling) in the three bands. Algorithms used to calculate water depth from remotely sensed airborne and satellite multispectral data are applied to the TUPS data and results compared. The TEJPS data have the advantage over most aircraft- and satellite-collected data because they were collected over an essentially uniform bottom type (smooth sandy bottom with steady slope) and have no atmospheric contamination. A new algorithm for depth calculation is proposed.

In this paper we discuss methods currently being implemented for the visual inspection of defects found on ground metal components. These are then identified and located for the purpose of removal/regrinding using a robotic manipulator. The visual sensing system and 3 dimensional vision algorithms are described.

This paper propose an user characterization technique for optical steppers. The purpose of such technique is to understand and to control those factors which affect stepper performances when fabrication of structures close or below the resolution specifications of the optical system is required. Two main factors are considered to limit stepper capabilities in submicron lithography: the imaging optics as a transmitter of high spatial frequencies with certain image intensity profile and the photoresist as a receiver of this optical information. The reported experiments use as the resist receiver a positive resist with a basic component added (0-4% by weight) in order to increase the resist transfer function and to decrease the K factor (from Rayleigh two points resolution criteria for isolated patterns, R = Kλ/N.A.). From spectral absorption of the in-house doped resist, we found that doping component concentration makes the process suitable for high resolution/ minimizing reflectivity/stepper target recognition. The imaging optics factors, a 0.31 N.A. /10X and 0.30-0.40 N.A./5X g-line steppers have been tested in the reversed resist process for linewidth change with defocus for various first/second exposure doses;exposure-defocus window;depth of focus for tangential/sagittal 1 micron lines/spaces patterns;lens capabilities to reproduce over all 10x10 mm field horizontal and vertical 1 micron lines. The latter is a useful indication in mixing-and-matching two steppers. Minimum 0.5 micron isolated patterns were reproduced in the reversed process, simultaneously in opposite polarities. The imaging optics was tested also for third order distorsion and errors of 50 ppm at optical field edges could be simply detected.

Spectral angle mapper (SAM) has been widely used as a spectral similarity measure for multispectral and hyperspectral image analysis. It has been shown to be equivalent to Euclidean distance when the spectral angle is relatively small. Most recently, a stochastic measure, called spectral information divergence (SID) has been introduced to model the spectrum of a hyperspectral image pixel as a probability distribution so that spectral variations can be captured more effectively in a stochastic manner. This paper develops a new hyperspectral spectral discriminant measure, which is a mixture of SID and SAM. More specifically, let xi and xj denote two hyperspectral image pixel vectors with their corresponding spectra specified by si and sj. SAM is the spectral angle of xi and xj and is defined by [SAM(si,sj)]. Similarly, SID measures the information divergence between xi and xj and is defined by [SID(si,sj)]. The new measure, referred to as (SID,SAM)-mixed measure has two variations defined by SID(si,sj)xtan(SAM(si,sj)] and SID(si,sj)xsin[SAM(si,sj)] where tan [SAM(si,sj)] and sin[SAM(si,sj)] are the tangent and the sine of the angle between vectors x and y. The advantage of the developed (SID,SAM)-mixed measure combines both strengths of SID and SAM in spectral discriminability. In order to demonstrate its utility, a comparative study is conducted among the new measure, SID and SAM where the discriminatory power of the (SID,SAM)-mixed measure is significantly improved over SID and SAM.

Most deep ultraviolet (DUV) resist models available today utilize the Dill parameters to characterize resist exposure. These models assume that the thickness of the resist remains constant through exposure and post-exposure bake (PEB). The thickness is only affected by development in the models when resist is removed from the exposed or unexposed regions, depending on whether it is a positive or negative resist. It has been observed that a number of DUV resists change thickness upon exposure. This effect is expected to have an impact on the post-exposure acid profile calculated for modeling purposes. In this paper, we present data on the thickness changes for different resists and the effect of exposure to PEB delay on the change.

Fundamental to vision enhancement systems for vehicles are sensors that provide precise, real-time attitude and heading information. While attitude and heading reference systems (AHRS) based on high-performance inertial components exist, such systems are traditionally very expensive and inapplicable to price-sensitive applications/markets. This paper demonstrates an AHRS that combines small, low-cost, solid- state inertial sensors with an advanced GPS-derived attitude determination technology. The resulting AHRS is inexpensive, rugged, and provides information with the accuracy and responsiveness needed to drive many enhanced/synthetic-vision displays, such as tunnel-in-the-sky guidance displays. The instrument also provides GPS position, velocity, and time information. Further, by using complementary and overlapping sources of information for integrity checking, the GPS/Inertial AHRS has robustness to individual sensor failures and can operate safely if GPS were to become unavailable.

It is well established that training backpropagation networks with noisy training sets increases the generalization capabilities of the network. Since input set noise is somewhat analogous to faults in the network, networks trained on noisy inputs should exhibit fault tolerance superior to that of similar networks trained on non-noisy inputs. This paper presents results of a study to determine the effect of noisy training sets on fault tolerance. Backpropagation was used to train three sets of networks on 7 X 7 numeral patterns. One set was the control and used noiseless inputs and the other two used two different noisy cases. Several network examples were trained for each of the three cases (no noise, 10% noise, and 20% noise). The noise was injected into each training image uniformly at random, and took the form of toggled (0 to 1 and 1 to 0) pixel values in the binary input images. After learning was complete, the networks were tested for their fault tolerance to stuck-at-1 and stuck-at-0 element faults, as well as weight connection faults. The networks trained on noisy inputs had substantially better fault tolerance than the network trained on noiseless inputs.© (1992) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

This paper describes a novel quantitative phase microscopy based on a simple self-referencing scheme using Michelson interferometry. In order to achieve the homogeneous reference field for accurate phase measurement, the imaging field-of-view (FOV) is split onto the sample and homogenous background areas. The reference field can be generated by rotating the relative position of the sample and homogenous background in the object arm. Furthermore, our system is realized using an extended depth-of-field (eDOF) optics, which allows quantitative phase measurement for an increase of the depth-of-field without moving objective lens or specimen. The proposed method is confirmed by experimental results using various samples such as polystyrene beads and red blood cells (RBCs).

Thinning on two-tone images is widely discussed. Two-tone images can be obtained by thresholding gray-level images. One major advantage of using two-tone images is that a binary image can be transformed into a continuous image to which many properties of topology can be applied. However, its tradeoff is that the thresholding function may lose some information of the original gray-level images. Rosenfeld introduced digital topology in early 1970's and fuzzy digital topology in late 1970's by the stimulation of Zadeh's fussy theory in 1965. It may be natural to process thinning directly on gray-level images. This paper proposes a template-based thinning algorithm on gray-level images and generates gray-level skeletons.© (1997) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

The element sensitivity factors method and the factor analysis are the most important methods for quantification of Auger depth profiles. The present paper puts forward a criterion for the decision in which cases the use of factor analysis is necessary for the quantification. The presented criterion uses the fact, that changed chemical bonds via sample depth are connected with changed element sensitivity factors. A chosen SiC-Si sample was investigated by Target Factor Analysis. The influence of data pretreatment like data selection, normalization and filtering are discussed.

Within the area of broadcasting and entertainment, stereoscopic displays are used to heighten the viewer's sense of excitement and quality. To evaluate these subjective experiences, an appreciation-oriented approach seems to be appropriate. Within this framework, this paper reports on two experiments in which we investigated the influence of image disparity, convergence distance and focus length on the subjective assessment of depth, naturalness, quality and eye-strain. Twelve observers with normal or corrected-to-normal vision and good stereopsis viewed a fully randomized presentation of stereoscopic still images that varied systematically in image disparity, convergence distance and focus length. In the first experiment observers were asked to rate, in separate counterbalanced sessions, their impression of depth, naturalness of depth and quality of depth. In the second experiment observers were asked to rate the eye-strain they experienced on a five point rating scale. Results indicate that observers prefer a stereoscopic presentation of images over a monoscopic presentation. A clear optimum for quality and naturalness judgments was found at 4 cm image disparity, which was also rated by observers as the stereoscopic condition that produced the least eye-strain. Extreme image disparities were found to be annoying, producing low quality and naturalness ratings accordingly. Although there was a strong linear relationship between naturalness and quality (a correlation of r equals 0.96), a small but systematic shift could be observed. This quality-naturalness shift is discussed in relation to similar, yet more pronounced findings in the color domain.

EMI sensors are used extensively to detect landmines, and operate by detecting the metal that is present in mines. However, mines vary in their construction form metal-cased varieties with a large mass of metal to plastic-cased varieties with minute amounts of metal. Unfortunately, there is often a significant amount of metallic clutter present in the environment. Consequently, EMI sensors that utilize traditional detection algorithms based solely on metal content suffer form large false alarm rates. We have at least partially mitigated this false alarm problem for high- metal content mines by developing statistical algorithms that exploit phenomenological models of the underlying physics. The Joint UXO Coordination Office (JUXOCU) is sponsoring a series of experiments designed to establish a performance baseline for a variety of sensors. The experiments to dat have focused on detection and discrimination of low-metallic content mines. This baseline will be used to measure the potential improvements in performance offered by advanced signal processing algorithms This paper describes the result of several experiments performed in conjunction with the JUXOCU effort. In our preliminary work, statistical algorithms have been applied specifically to the problem of detection of low-metal mines, and dramatic performance improvements have been observed with respect to the baseline performance. However, these algorithms improvements have been observed with respect to the baseline performance. However, these algorithms were statistical in nature, did not incorporate phenomenological models, and exploited spatial information. The tradeoffs among these various factors are explored in this paper, along with the performance of alternative statistical approaches. In addition, approaches to classification of the mine-type are discussed and the performance of such classifiers is presented.

Virtual manufacturing that is enabled by rapid, accurate, full-chip simulation is a main pillar in achieving successful mask tape-out in the cutting-edge low-k1 lithography. It facilitates detecting printing failures before a costly and time-consuming mask tape-out and wafer print occur. The OPC verification step role is critical at the early production phases of a new process development, since various layout patterns will be suspected that they might to fail or cause performance degradation, and in turn need to be accurately flagged to be fed back to the OPC Engineer for further learning and enhancing in the OPC recipe. At the advanced phases of the process development, there is much less probability of detecting failures but still the OPC Verification step act as the last-line-of-defense for the whole RET implemented work. In recent publication the optimum approach of responding to these detected failures was addressed, and a solution was proposed to repair these defects in an automated methodology and fully integrated and compatible with the main RET/OPC flow. In this paper the authors will present further work and optimizations of this Repair flow. An automated analysis methodology for root causes of the defects and classification of them to cover all possible causes will be discussed. This automated analysis approach will include all the learning experience of the previously highlighted causes and include any new discoveries. Next, according to the automated pre-classification of the defects, application of the appropriate approach of OPC repair (i.e. OPC knob) on each classified defect location can be easily selected, instead of applying all approaches on all locations. This will help in cutting down the runtime of the OPC repair processing and reduce the needed number of iterations to reach the status of zero defects. An output report for existing causes of defects and how the tool handled them will be generated. The report will with help further learning and facilitate the enhancement of the main OPC recipe. Accordingly, the main OPC recipe can be more robust, converging faster and probably in a fewer number of iterations. This knowledge feedback loop is one of the fruitful benefits of the Automatic OPC Repair flow.

Faces provide important characteristics of a person’s identification. In security checks, face recognition still remains the method in continuous use despite other approaches (i.e. fingerprints, voice recognition, pupil contraction, DNA scanners). With an associative memory, the output data is recalled directly using the input data. This can be achieved with a Nonlinear Holographic Associative Memory (NHAM). This approach can also distinguish between strongly correlated images and images that are partially or totally enclosed by others. Adaptive wavelet lifting has been used for Content-Based Image Retrieval. In this paper, adaptive wavelet lifting will be applied to face recognition to achieve an associative memory.

As our applications continue to become more sophisticated, the demand for more storage continues to rise. Hence many businesses are looking toward data warehousing technology to satisfy their storage needs. A warehouse is different from a conventional database and hence deserves a different approach while storing data that might be retrieved at a later point in time. In this paper we look at the problem of storing and retrieving medical image data from a warehouse. We regard the warehouse as a pyramid with fast storage devices at the top and slower storage devices at the bottom. Our approach is to store the most needed information abstract at the top of the pyramid and more detailed and storage consuming data toward the end of the pyramid. This information is linked for browsing purposes. In a similar fashion, during the retrieval of data, the user is given a sample representation with browse option of the detailed data and, as required, more and more details are made available.© (1995) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

In this paper we demonstrate the preparation of monodisperse particles from a liquid crystalline elastomer with a preferred director orientation. For this we use a microfluidic setup to create droplets from a liquid crystalline monomer which are polymerized in the liquid crystalline phase while flowing. When the obtained particles are heated above the transition temperature of the nematic phase, they show a reversible shape change from spherical to cigar-like. We show, that we can control the size as well as the polydispersity of these microactuators. If the particles are prepared in non-flowing conditions, no or an undefined shape change is observed. Particles polymerized in the isotropic phase show no shape deformation as well. Additionally we provide an experimental proof for the stability of these structures versus acidic and basic conditions.

Conventional test methods use optical switches for testing large port count devices such as couplers and splitters. This method is both capital and labor intensive and the cost of such a system runs between $250 to $300 per test channel. This paper describes a very reliable and low-cost approach for testing a large number of fibers using a mechanical indexer. The method not only reduces the setup time considerably but also offers significant savings in capital equipment. Using this concept, a test system capable of testing 600 channel has been built at a cost of less than $50 per test channel.

The Galileo National Telescope is a 3.6 meter Alt-Az telescope installed at the Astronomical Observatory of the Roque de Los Muchachos in La Palma, Canary Islands. The Galileo drive and control systems were designed and developed by the Technology Working Group of the Capodimonte Astronomical Observatory, Naples. Apart from a short review of the drive system, the paper describes a novelty in the adaptive preload sub-system.

In this paper, the simulation and design of a waveguide for water turbidity sensing are presented. The structure of the proposed sensor uses a 2x2 array of multimode interference (MMI) coupler based on micro graphene waveguide for high sensitivity. The beam propagation method (BPM) are used to efficiently design the sensor structure. The structure is consist of an array of two by two elements of sensors. Each element has three sections of single mode for field input tapered to MMI as the main core sensor without cladding which is graphene based material, and then a single mode fiber as an output. In this configuration MMI responses to any change in the environment. We validate and present the results by implementing the design on a set of sucrose solution and showing how these samples lead to a sensitivity change in the sensor based on the MMI structures. Overall results, the 3D design has a feasible and effective sensing by drawing topographical distribution of suspended particles in the water.

At the receiver of an ultrashort-pulse optical code-division multiple-access (OCDMA) system, a nonlinear thresholder is needed to discriminate between the correctly decoded short pulse and the interference that appears to be a pseudorandom signal. It has been demonstrated that the self phase modulation (SPM) effect can be used to realize this nonlinear thresholder. The performance of a system that exploits this phenomenon is analyzed in this paper. If the spreading code is random, the electrical field of the interfering signal from the multiple users can be shown to be a complex Gaussian random process. The broadened power spectral density (PSD) function caused by the SPM effect can be calculated. When "1" is transmitted, the correctly decoded signal from the desired user, which is a deterministic waveform, is added to the Gaussian random process. Beating between the two signals causes random fluctuations in the power. Since the strength of the SPM effect is proportional to the variation rate of power, the broadened signal spectrum will appear random. The Monte Carlo method is used to obtain the properties of the decision statistic. Finally, the bit-error rate (BER) is calculated, and the simulation results are presented. The result reveals that the performance of the SPM-based nonlinear receiver can outperform the ideal linear receiver in some circumstances.